CN1160992A - Differentially formed luggage with integrally molded frame - Google Patents

Abstract

A differential pressure formed piece of luggage has a lid shell(40) and base shell(80). The lid shell(40) has a lid wall member(42) which extends perpendicularly from the lid shell into the interior of the luggage. A lid flange(44) extends perpendicularly downwardly from the lid wall member(42). The base shell(80) has a base wall member(82) which extends perpendicularly into the luggage interior from the base shell(80). Extending obliquely from the base wall member(82) is a base flange(84). The lid flange(44) and base flange(84) overlap in a nonparallel fashion when the luggage is closed. The luggage is held in the closed position by a catch(39) on the lid wall member(42) mating with a latch(90) on the base wall member(82). The two shells are also aligned by the use of alignment pins(110) and recess(111) on the shells(40, 80).

Description

Differentially formed luggage with integrally molded frame

Field of the invention

This invention relates generally to vacuum-formed and pressure-formed products and processes and, in particular, to hard-sided luggage.

Background technique

Luggage cases with hard side walls are generally composed of two shells, commonly referred to as a lid shell and a bottom shell. Typically, each shell is formed from a thin sheet of thermoplastic material that is molded into the shape of a container. The housing is usually in the shape of a rectangular box with rounded corners, a peripheral edge forming one side of its opening. The peripheral edges of the two shells substantially correspond to each other so that the cover shell can be placed concave side down on the concave side up bottom shell such that their respective edges are aligned and/or in contact. After such placement, the two shells can be joined by hinges and releasable latches as is known in the art to form a container with an accessible interior space.

The main purpose of making a luggage case with hard side walls is to provide a shell which is both light in weight and high in strength. In addition to being puncture-resistant and impervious to breakage, a hard-sided enclosure of desirable strength should also be resistant to overall deformation of its overall shape due to external twisting or flexing forces. An advantage of hard sided luggage should be its stiffness, ie withstand forces without much twisting or bending, although some small deformability of the hard sided case is desirable. Any type of twisting of the luggage case may compromise the contents of the luggage case and may also damage the hinges and cause the latch to fail.

The bonded shell of a luggage case with hard sides is usually molded using one of two manufacturing processes. Injection molding involves injecting molten thermoplastic resin, typically polypropylene, under pressure into a heavy steel mold to form a substantially complete shell that includes an integral frame and mountings for wheels, handles, etc. . The nature of the injection molding process and its machinery somewhat limits the final configuration of the molded article. Injection molding also requires the use of very high pressure systems, which can be expensive to acquire and maintain, and which can limit the variety and rapid modification of products.

Another major process, commonly referred to as "vacuum forming," involves applying force to a heated sheet of thermoplastic material against a convex or concave mold. The driving force is provided by a pressure differential whereby the differential pressure of the air on opposite sides of the sheet moves the sheet against the die. Strictly speaking, "vacuum forming" means creating a "negative" pressure or reduced pressure in the space between the sheet and the mold so that the sheet is pulled or "suctioned" towards the mold. Additionally, "pressure molding" involves creating a space of "positive" or elevated pressure on the side of the sheet opposite the mold, thereby blowing or pushing the sheet toward the mold. Also, pressure molding and vacuum molding can and are often performed simultaneously in the same equipment, and this combined process is sometimes referred to generically as "vacuum molding". Unless the specific terms "vacuum forming" or "pressure forming" are used, the general term "differential pressure forming" will be used herein to mean vacuum forming only, pressure forming only, or a combination of both processes.

In differential pressure forming, the heat-bent sheet is removed from the die after it has conformed to the shape of the die surface. Subsequently, the three-dimensionally shaped shell is trimmed to size and edge segments (sometimes referred to as waste or offcuts) are removed which are required for processing but are not part of the final product. Traditionally, in order to make the final box body have proper rigidity, the shell is riveted or stapled to a separate frame member, usually a stamped aluminum or magnesium alloy. metal frame. The hinges are attached to the frame, followed by the other hardware and lining pieces to form the complete case.

One disadvantage of the standard differential forming process used to make luggage is the need to attach separate frame members to the shell. A typical differentially formed shell is itself relatively crush and puncture resistant, has deformable strength when stressed, and deforms plastically and elastically when subjected to any significant load. Frames, on the other hand, are lightweight and strong, but less prone to deformation. The rigidity of the frame and the deformability of the shell do not respond to each other, especially in those areas of local stress where the shell and frame are riveted or stapled together. At these heightened stress locations, rivets or staples tend to pull through, or tear, the thermoplastic housing. In addition, the frame of magnesium or aluminum adds to the cost of the case; the frame itself often requires many finishing steps, since this frame is the main aesthetic distinction of the finished luggage case. Also, the frame is often used to hide the rough edges of the trimmed and formed shell.

Another problem often encountered in the conventional vacuum forming process of making containers is unwanted wall thinning in the finished product, especially near corners and edges. This is a serious disadvantage to the strength of the container, since the corners and edges are the parts of the container which are subjected to greater impact and bending stresses.

Another problem encountered in the prior art is the restriction imposed on the shape of the final product due to the need to remove the finished product from the mold. Once the thermoplastic material is cold, the finished product is simply pulled directly from the mold. In order for this separation process to be completed without cutting the molded product, the mold must be shaped such that no part of the molded product interlocks with the mold itself; If there is no protrusion or recess into which material is pressed, the product will interlock with the mold, preventing the product from being pulled out of the mold in the direction in which separation is intended. Unfortunately, this limitation on the shape of the mold hampers the design of containers, including the design of integral framed luggage shells, in the prior art.

Blow molding and rotational molding processes have also been used to make shells for luggage. In luggage applications, blow molding and rotational molding have several limitations. For example, blow molding and rotational molding processes have poor thickness control, resulting in some thin spots on the wall. These prior art processes also have limitations with respect to the shape and composition of the products produced and cannot easily line or finish interior surfaces.

Accordingly, there remains a need for a luggage product manufactured using a relatively simple and inexpensive differential pressure molding process, but which overcomes the shortcomings of existing products and improves upon the manufacturing process. Against this background, the present invention has been proposed.

Summary of the invention

The present invention relates generally to differential pressure forming products and processes, and more particularly, to luggage cases having hard side walls. The container or luggage unit has two plastic shells, a lid shell is pivotally connected to a bottom shell, each shell has a bottom and sides extending to a flange. When the two shells are placed one on top of the other in a closed position so that their flanges are substantially aligned, the two shells form an interior space between them in which clothing and personal items can be placed . The present invention is an improvement in housings for integrally forming a frame with each housing. The integrally molded frame includes: a cover flange offset by the cover and forming a peripheral edge of the cover; a cover wall connecting the cover flange to the cover a sump flange which is offset by the sump and forms a peripheral edge of the sump; and a sump wall which connects said sump flange to the sump. When the two shells are in a closed state, the flange of the cover shell overlaps at least a part of the flange of the bottom shell. The device according to the invention comprises a latch means provided on these wall parts for releasably connecting said two wall parts together. Thus, the differentially formed sump has a sump wall portion integrally formed with, and suspended from, a sump side portion substantially adjacent to the sump projection. and the sump flange is integrally formed with and extends from the sump wall. Likewise, the differentially formed cover has a cover wall integrally formed with and suspended from a cover side substantially adjacent to the cover projection. At least a section of the rim, and the cover flange is integrally formed with and extends from the cover wall. In a closed state, the cover shell alignably engages with the bottom shell to enclose a space between said shells, and when the two shells are thus aligned and closed, the cover shell flange and the bottom shell The housing flanges are slidably overlapped and two wall portions form a channel between at least one section of each of said housing flanges. When the cover shell and the bottom shell are in a closed state, the latch means for releasably connecting the two shells together as a releasable connection means is arranged at least partially in the in the recessed channel.

The invention is not limited to the combination of two housings, but also includes a single housing formed from a sheet of thermoplastic material, characterized in that a frame comprises an integral extension of at least one side of the housing. The frame is molded from the sheet of material and extends substantially continuously along at least a portion of the housing flange.

A primary object of the present invention is to provide a container with an integrally formed frame.

A major advantage of the present invention is that container products can be produced in a manner that provides improved container strength without a net increase in material requirements.

Other objects, advantages and unique features of the application of the present invention, and further contents will be described in part in the following detailed description in conjunction with the accompanying drawings, and for those skilled in the art, in part by examining the following contents will become apparent, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

Brief description of the drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description serve to explain the principles of the invention. These drawings are only for the purpose of illustrating preferred embodiments of the present invention, and are not intended to limit the present invention. In the attached picture:

Figure 1 is a perspective view of a preferred embodiment of the luggage case assembly of the present invention, the case being partially open;

Fig. 2 is the front view of the embodiment shown in Fig. 1;

Figure 3 is a front view of the luggage case device of the present invention, showing the case in a closed state;

FIG. 4 is a partial sectional side view of the luggage case device of the present invention in a partially open state, the section being taken substantially along the section line 4-4 in FIG. 2;

Fig. 5 is a partial cross-sectional side view of the embodiment shown in Fig. 3, and the section is substantially taken along the section line 5-5 in Fig. 3;

Figure 6 is an enlarged partial cutaway side view of the luggage case assembly of the present invention showing details of the latch and handle member;

Figure 7 is a top view of a preferred embodiment of the luggage case assembly of the present invention showing the case fully opened;

Fig. 8 is a partially enlarged view of the hinge portion of the embodiment shown in Fig. 7;

Fig. 9 is a partially enlarged view of the latch part of the embodiment shown in Fig. 7;

Fig. 10 is a partial enlarged view of the luggage case device of the present invention in a slightly opened state, the cutaway part showing the details of the latch, handle and clips;

Figure 11 is a cross-sectional side view of a preferred embodiment of the manufacturing apparatus of the present invention, showing the platen assembly in a separated state;

Figure 12 is a top cross-sectional view of a portion of the embodiment shown in Figure 11, the section being taken substantially along section line 12-12 in Figure 11, showing the sidedraw die in a substantially retracted position ;

Figure 13 is a side sectional view of the embodiment shown in Figure 11 showing placement of a molded sheet of thermoplastic material;

Figure 14 is a side cross-sectional view of the preferred embodiment showing the sidedraw die in a substantially extended position;

14A is an enlarged fragmentary side cross-sectional view of a portion of the embodiment of FIG. 14 showing details of the pinch-off plates, side pull dies and seal plates, while the pinch-off plates are in a lowered position;

Figure 14B is another view of the embodiment shown in Figure 14A, showing the pinch-off plate in a raised position; and

Figure 15 is a top view of the embodiment shown in Figure 12 showing the sidedraw die in a substantially extended position.

DESCRIPTION OF THE PREFERRED EMBODIMENT (BEST MODE FOR CARRYING OUT THE INVENTION)

The improvement of the present invention pertains to the manufacture of luggage with hard sides, but it will be appreciated that the principles of the present invention are certainly applicable to the manufacture of containers in general. The advantages of the present invention can be realized whenever it is desired to provide an integrally fabricated frame with respect to a thin hollow shell of thermoplastic material having an opening leading to the shells connected by the integrally fabricated frame middle.

Attention is drawn to Figure 1, which shows a perspective view of a luggage case 30 made in accordance with the present invention. The article shown is a "pullman" type of case, but the invention is equally applicable to the popular "upright" type of luggage. Additionally, although the case 30 shown in FIG. 1 has no wheels or handles, it will be readily understood that alternative embodiments of the luggage device of the present invention may have wheels and pull handles as known in the art so that the Wheels to drag luggage, not by hand.

See Figure 1-3. The case 30 of the present invention includes a cover shell 40 and a bottom shell 80 . The process of the present invention can be used to make the bottom shell 80 and the cover shell 40, and, in the preferred embodiment, the shells 40, 80 are very similar in structure and shape. Alternative variations of the invention may include an embodiment in which only one of the shells of the case 30 is made in accordance with the invention; indeed, one of the shells (perhaps the cover shell 40) may consist of stitched cloth panels, usually Known as the "soft side" structure.

In the preferred embodiment, each housing 40, 80 is molded from a thin sheet of thermoplastic material. In particular, the invention is well suited for molding sheets of acrylonitrile-butadiene-styrene terpolymer (ABS plastic). The invention may also be practiced with vacuum formable polypropylenes such as low melting polypropylenes. Thus, the present invention can be used to form polypropylene, and the present invention can produce an inventive product that has the appearance of being injection molded even though it is differentially formed.

Blank sheets are generally rectangular and planar sheets of material, perhaps extruded sheets, with edge portions surrounding a central portion. In the following description, the sheet will be described referring to a center portion, an edge portion and trim portions. The offcut portion is a relatively small portion of the overall sheet formed by the sheet boundary adjacent the original edge of the sheet. This offcut portion is needed to secure the sheet in the vacuum forming machine; it does not become part of the finished product, but is trimmed off during or immediately after the molding process is complete. The central portion of the sheet is the majority or main portion of the sheet which is molded into the main body of the housing. The ratio of the size of the edge portion to the center portion can vary significantly from one product to another, the edge portion being the portion of the sheet forming the periphery of the center portion; its outer border being the portion intersecting the trim portion. The edge portion becomes an integral part of the finished product and actually forms the edge of the finished shell once the offcut portion has been trimmed away. The sheet is heated to make it soft and pliable, and although it is in a softened state, it can be molded into a shape similar to the bottom shell 80 shown in FIG.

Except where stated otherwise, the description of the bottom case 80 is equally applicable to the description of the cover case 40 . In the preferred embodiment, the shells 40, 80 are each fabricated to obtain a generally concave shape with a bottom 81 and integral side portions 83a, 83b extending away from the bottom 81. In this way, the side portions 83a, 83b and the bottom 81 enclose the inner space of the casing 80 with five sides, and articles can be stored in this space. However, the device of the present invention is not limited to any particular general shape and may include cylindrical containers. The molding and shape of certain faces of the side portions 83a, 83b is an aspect of the invention and will be further explained.

The side portions 83a, 83b extend away from the base 81 to a flange 86 . The cover shell 40 has a cover shell flange 46 and the bottom shell 80 has a bottom shell flange 86 . The flanges 46,86 preferably extend around the entire perimeter formed by the side portions of the respective housings 40,80. Preferably, but not necessarily, when the case 30 is completely closed and placed on a horizontal support surface, at the position where the plane tangent to the space of the housing 80 is substantially perpendicular to the support surface, the flange 86 is exposed, such as shown in Figure 3.

The two housings 40,80 are shaped to provide a frame that is integrally molded about their respective flanges 46,86. This frame has many advantages in that it is molded integrally with the housing, eg from the same sheet of thermoplastic material as the housing. The formation of the integral frame eliminates the need to staple or otherwise attach a separate frame, such as an extruded clip, to the housing. This greatly reduces fabrication time and cost, and avoids problems associated with attaching a separate rigid frame to the deformable shell.

See Figures 1 and 2 in conjunction. The general description of housing 80 likewise describes corresponding and analogous components of cover shell 40 . In the preferred embodiment, the integrally molded frame includes a wall portion 82 depending from the housing 80 in the vicinity of a flange 86 and a flange 84 extending from the wall portion 82 . Each housing 40, 80 has a wall portion 42, 82 extending inwardly (ie, into and toward the interior space) from a respective flange 46, 86 . The cover shell 40 has a cover shell wall 42 and the bottom shell 80 has a bottom shell wall 82 . As shown in FIGS. 1 , 2 and 7 , each wall portion 42 , 82 , like the flanges 46 , 86 , preferably (but not necessarily) extends about the entire edge of the case 30 . In the preferred embodiment, the wall portions 42, 82 are vertically depending from the flanges 46, 86 of the respective housings 40, 80, i.e., the wall portions 82 are substantially parallel to a horizontal support surface on which the case 30 may be placed. on the surface (see Figure 3). Thus, the angle that wall portion 82 makes with respect to the immediately adjacent side portion 83a or 83b of housing 80 when viewed in cross-section (eg, in FIG. 4 ) is preferably about 90 degrees. However, in another embodiment, the angle between a side portion of the housing and its overhanging wall portion may be inclined at any suitable angle.

Bottom shell flange 84 and cover shell flange 44 protrude from respective wall portions 42 , 82 . Like the walls 42 , 82 , the flanges 44 , 84 are integrally molded from the same sheet of thermoplastic material as their respective housings 40 , 80 . Thus, the housing 80, the wall portion 82 and the flange 84 are not separable parts, but rather extensions of one another, all molded from the same sheet of virgin thermoplastic material. One of the flanges 44 , 84 preferably the cover flange 44 extends perpendicularly from its corresponding wall portion 42 . As shown in Figures 1 and 2, the flanges 44, 84 extend outwardly from the wall portions 42, 82, ie they project outwardly from the interior space.

The free edges of the flanges 44,84 form respective peripheral edges 48,88 of the housings 40,80. Peripheral rims 48, 88 extend about the periphery of the open side of each housing 40, 80, thereby defining and dimensioning the opening.

As shown in FIGS. 1-3 and 7, the bottom shell 80 and the cover shell 40 are configured to be connected for use, and the cover shell 40 is aligned on top of the bottom shell 80. As shown in FIG. When the case 30 is closed (see FIG. 3), the peripheral edges 48, 88 abut in close proximity. The housings 40, 80 are pivotally connected together along corresponding lengths of their respective back sides 45, 85 (see FIG. 1). The pivotable connection is preferably a pair or more of hinges 71, 71', or a piano hinge, or similar connection. Therefore, the cover shell 40 can be swung upwards from the bottom shell 80 to expose the internal storage space of the box, or can be lowered to completely enclose the internal space and form the internal space.

Alternative embodiments of case 30 may be without hinges. For example, a box or box-shaped container may consist of a lid that slides directly onto the base in the manner common to hat boxes and shoe boxes. In such an embodiment, the flanges 44 and 84 would still slide over each other in an overlapping fashion; the cover shell 40 and bottom shell 80 could simply be separated completely, with no hinge connection. A latch or other type of latch on one of the housings engages one or more ridges surrounding the other housing to secure the two housings together.

4 and 5 show partially enlarged cross-sections of the luggage case body 30 of the present invention. These figures show in further detail the specific configuration of the overall framework features of the device of the invention. 4 is a cross-sectional view of the housings 40, 80 taken substantially along section line 4-4 in FIG. 2, the housings 40, 80 being oriented when the case 30 is partially open. Figure 5 is a cross-sectional view taken substantially along section line 5-5 in Figure 3, showing the relative positions of the components of the overall housing frame when the case 30 is closed. The housings 40, 80 may be molded in gently curved cross-sections extending to their respective flanges 46, 86. At each flange 46,86, the housing 40,80 is bent inwardly to create the wall portion 42,82 according to the machining process previously described. In the preferred embodiment, each wall portion 42, 82 protrudes into the interior space enclosed by the case 30, substantially perpendicular to an imaginary plane that meets the respective shell at its flange 46 or 86. The curves of bodies 40, 80 are tangent. The distance that the wall portions 42, 82 protrude inward is not absolutely critical, but it must be of a certain size (for example, about 3.0 cm in a standard-sized "people pull" (pullman) type luggage), in order to The perimeter of the housing provides the required section moment to provide proper stiffness to the housing 40,80.

Cantilevered from the cover wall portion 42 and from the bottom wall portion 82 are the cover flange 44 and the bottom flange 84 , respectively. The housing flanges 44, 84 are formed substantially simultaneously with the formation of the walls 42, 82, using the same inventive process. Like the wall portions 42,82, the housing flanges 44,84 are molded from the original sheet of thermoplastic material so that they are integral extensions of their respective wall portions 42,82. In the preferred embodiment, the cover flange 44 extends perpendicularly from the wall portion 42 ; the cover flange 44 extends downwardly toward the bottom case 80 . Bottom shell flange 84 extends upwardly toward cover shell 40 as shown in FIG. 4 . However, the sump flange 84 is preferably sloped or skewed relative to the sump wall 82 . It has been determined that having the bottom casing flange 84 with a slight inward (towards the enclosed space) slope facilitates the smooth and automatic sliding of the cover casing flange 44 over the bottom casing flange 84 and around the bottom casing flange. 84. Facilitates self-alignment and alignment of the housings 40, 80 during closing of the case 30.

The size and general cross-sectional configuration of the base housing flange 84, base housing wall portion 82, cover housing flange 44 and cover housing wall portion 42' are preferably uniform around the entire perimeter of the housings 40,80. However, it should be noted that alternative effective embodiments of the present invention may vary the size (or configuration) of the walls 42, 82 and flanges 44, 84 as they move around the perimeter of the respective housing 40 or 80. The specific location on the map varies. Also, alternative embodiments of the present invention may include discontinuities in the flanges 44, 84 and/or the walls 42, 82 to accommodate other structural members, reduce weight, or meet other requirements. Thus, while in the preferred embodiment the frame comprising the walls 42, 82 and housing flanges 44, 84 extends completely around the opening of each housing 40, 80, other embodiments may only extend around the housing perimeter. Some parts provide frame pieces.

Thus, the advantage of molding a sheet of thermoplastic material to form the walls 42, 82 and flanges 44, 84 and incorporating them into the housing 40, 80 is that an integral frame is produced, eliminating the need for a separate The frame parts need to be mounted on the shell. Each housing 40 , 80 is stiffened and stabilized by the rigidity provided by its associated flange 44 , 84 and in particular by its respective wall portion 42 or 82 . This increase in stiffness is observed in any single shell 80 that is considered isolated (eg, when the case 30 is opened, or in those embodiments of the invention that are associated with only one rigid shell). Additional stiffness comes from the moment of inertia of the section of the housing 80 , the flange 84 and the wall 82 next to the flange 86 . The moment of inertia of flange 84 , wall portion 82 and housing 80 about any imaginary axis in housing 80 (eg, an axis parallel to flange 86 ) increases due to the relative displacement of housing flange 84 away from housing 80 . By offsetting the flanges 44,84 from their respective housings 40,80 and rigidly connecting the housings and flanges to the walls 42,82, the resistance of the housings to bending is significantly improved. The wall portion 82 in combination with the flange 84 effectively acts as an L-shaped beam frame surrounding the opening of the housing 80 and being completely integral with the housing 80 .

One notable aspect of the preferred embodiment of the device of the present invention is the operative relationship of the lid housing wall 42 and lid housing flange 44 to the base housing wall 82 and base housing flange 84 . This relationship can be best understood with reference to Figures 2, 4 and 5. FIG. 5 shows in cross-section the relative positions of the two housings 40 , 80 , and their respective overall frames when the case 30 is fully closed, as shown in FIG. 3 . These figures show that in the preferred embodiment, the cover housing wall 42, cover housing flange 44, base housing wall 82 and base housing flange 84 are carefully dimensioned so as to cooperate to provide an improved cabinet . The cooperating action of the cover frame with the corresponding components of the bottom case 80 provides an improved manner of closing the case and increases the rigidity and security of the closed case.

FIG. 5 illustrates an overlapping relationship provided between lid flange 44 and bottom flange 84 when case 30 is closed. The cover shell wall portion 42 extends inwardly from the cover shell 40 for a distance that is less than the inwardly extending distance of the bottom shell wall portion 82 . This difference in distance is preferably approximately equal to the combined thickness of the two flanges 44,84. Therefore, the peripheral dimension of the peripheral edge 88 of the bottom shell is slightly shorter than that of the peripheral edge 48 of the cover shell. Figures 4 and 5 also show that the bottom shell flange 84 extends in length a slightly longer distance than the cover shell flange 44 (for example, this difference in distance is approximately equal to the thickness of one of the flanges). These differences in dimensions between the frame components of the lid shell 40 and corresponding components of the bottom shell 80 provide the overlapping relationship shown in FIG. 5 when the shells 40, 80 are brought together to close the case. Cover flange 44 overlaps bottom casing flange 84 and is in light slidable contact with bottom casing flange 84 . In addition, the cover peripheral edge 48 preferably contacts the base wall 82 when the case 30 is closed.

An added benefit of the configuration of the flanges 44, 84 is that they interact during closure of the case 30 so that the case 30 is properly closed. The housings 40, 80 are substantially self-aligning during closing due to the slightly longer circumference of the peripheral edge 48 of the cover housing 40 than the peripheral edge of the bottom housing 80 and due to the fact that the housings 40, 80 are are hinged together at least in one location so that the lid shell flange 44 is positioned outwardly of the bottom shell flange 84 (see FIG. 8 ). The cover shell flange 44 will always slide out of the bottom shell flange 84, and around the bottom shell flange 84, and subsequently, rest on the bottom shell wall 82, as shown in Figure 5, even when the two shells are initially closed. The same goes for bodies 40, 80 not being properly aligned.

This arrangement of the flanges 44, 84 and the walls 42, 82 gives a strength advantage when the box 30 is fully closed. Figure 5 shows that when the case 30 is fully closed, the walls 42, 82 are preferably substantially parallel and separated by a distance (e.g., about 3.0 cm in a standard "pullman" type luggage case) . Therefore, when box 30 is closed, the function of wall portion 42,82 and flange 44,84 of respective casing 40,80 is to cooperate to form a U-shaped beam frame around the periphery of box 30; , 82 serve as the legs of the U-beam, while the flanges 44, 84 function as the back of the beam. This cooperative strength function is greatly enhanced when the housings 40, 80 are snapped together, for example, when a latch mechanism securely connects one wall portion 42 to the other wall portion 82 . The cooperating work of the flanges 44, 84 and the wall portions 42, 82 of the two shells 40, 80 forming a kind of U-shaped beam frame around the closed box 30 serves to significantly increase the box's resistance to bending, warping and warping. The ability to bend, or fold. Thus, despite the absence of an expensive, separately mounted frame, case 30 still provides very secure storage of the contained items. Externally applied forces are readily transmitted from either housing to the other via the walls 42,82 and flanges 44,84.

Additionally, the overlapping and joined flanges 44, 84 and walls 42, 82 serve to add strength to the case 30 to withstand the carrying load when the case 30 is filled, closed, and carried by the carrying handle 34. In the preferred embodiment shown in FIGS. 3 , 5 , 6 and 10 , the carrying handle 34 of the case 30 is securely attached to the wall 42 of the cover 40 . Accordingly, the force of the weight of the loaded box 30 starts to be transmitted from the handle 34 to the cover shell 40 . However, in a preferred embodiment, these carry loads, in addition to the loads distributed on and generated by the cover 40, are also transferred directly to the cover wall 42 by the carrying handle 34, and then Transfers to the clips 39, 39', then to the attachment latches 90, 90', and then to the bottom case wall 82 for transfer to the bottom case 80 itself. Certain loading forces (such as the weight of a user sitting on the case when the case is in the upward standing position, and the carrying force on the handle 34) are also transferred directly to the bottom case projection by the cover case flange 44. The rim 84 is then passed to the bottom casing wall 82 and is dispensed through the bottom casing 80 . The overlapping configuration of the flanges 44, 84 engages the alignment pins 110, 110' into the alignment holes 111, 111', and uses a pin 90 and clip 39 to bridge the opposing wall 42, 82, so that the load originally applied to the case 30 at the handle 34 or elsewhere is effectively transmitted to the entire case 30.

FIG. 8 shows in detail the use of one or more hinges 71 to pivotally connect the cover shell 40 to the bottom shell 80 . The connection shown in FIG. 8 is fastened by screws, rivets or the like to the hinges 71 on the wall 82 of the bottom shell and the flange 44 of the cover shell. Hinge 71 may be suitably fastened to cover housing wall 42 for added strength and durability. Thus, the hinge 71 is mounted to the hardest, strongest portion of the housing 40,80, ie, the integral frame member formed by the flanges 44,84 and the wall portions 42,82. The hinge 71 is fixedly mounted on the bottom shell wall 82 so that when the cover shell 40 is closed down on the bottom shell 80, the cover shell flange 44 can be swiveled into an overlapping position relative to the bottom shell flange 84. When the box 30 is fully closed, the hinge 71 is on the outside of the box 30 and the lid shell flange 44 is placed between the hinge 71 and the bottom shell flange 84 .

Figures 2, 6, 7 and 10 taken together illustrate the preferred mounting of the carrying handle 34 to the cover shell 40, and the preferred mounting of at least one latch 90 to the bottom shell 80. The installation of the handle assembly consisting of the handle 34, the handle baffle 35 and the handle base 36 on the cover shell 40, and the installation of the latches 90, 90' on the bottom shell 80 are different from conventional techniques. In the known art, the handle assembly and latch are usually mounted on the bottom shell, often for reasons related to the provision or configuration of a separate metal alloy frame. The arrangement of the present invention allows the handle 34 to be securely attached to the cover 40, which is advantageous to the user. Intuitively, the handle 34 should be attached to the cover 40 where it can be used as a handle for lifting the cover 40 when opening the case 30 .

However, the latches 90, 90' of the preferred embodiment are on the bottom housing 80. In the preferred embodiment, the latches 90, 90' engage the catches 39, 39' on the cover 40 to secure the case 30 in the closed condition.

Attention is drawn to Figures 6 and 10, which illustrate the mounting of the handle 34 to the cover 40 in detail. The handle 34 and the handle guards 35 , 35 ′ are fixedly connected to the handle base 36 . Handle base 36 is preferably securely mounted to the exterior surface of cover wall 42 by rivets 38, 38' or the like. Preferably, but optionally, on the outside surface of the cover wall portion 42 . Preferably, but alternatively, a thin rigid back panel 37 can be attached to the inside surface of the cover shell wall 42 (see FIG. 6 ), opposite the handle base 36, to provide reinforcement and a An incompressible surface against which a nut can be screwed, or a rivet can be pulled. The mounting of the handle base 36 to the cover shell wall 42 is preferably done without attaching it to the cover flange 44 because the flange 44 is a cantilever away from the body of the cover 40. Flanges are somewhat more susceptible to deformation, bending or breaking.

Figures 6, 7 and 10 show the clips 39, 39' protruding through the handle base 36. Each clip 39 is secured to the cover wall 42 and extends inwardly, forming a small space between the clip 39 and the inner side surface of the cover wall 42 . The latch member 90 engages the catch 39 to lock the case 30 in a closed position in a manner to be described hereinafter.

Figures 6, 7 and 10 also show that case 30 is preferably provided with a pair of latches 90, 90' for fastening the shells together to lock case 30 in its closed condition. Alternative embodiments of the device of the invention may have one, three or even four latch mechanisms. In a preferred embodiment, the latches 90, 90' are spring operated "lift lever" type latches. The general principles and operation of lifter bar type latches are known in the art; however, the latches 90, 90' used in the preferred embodiment of the present invention are modified to operate in an innovative manner and are mounted in an unconventional manner. onto box 30. The latches 90, 90' are attached to the bottom housing 80 as shown. Importantly, the latches 90, 90' are attached to the bottom casing wall 82 and preferably do not fit over or contact the bottom casing flange 84. In the preferred embodiment, the latch 90 is spaced from the bottom housing flange 84 to provide a gap or slot space between the bottom of the latch 90 and the bottom housing flange 84 .

As best shown in Figures 6, 9 and 10, the latch 90 is securely mounted directly to the outside surface of the bottom housing wall 82 using rivets 91, 91' or the like. Screws or rivets 91, 91' pass through pins 90, through bottom housing wall 82, and they may be fastened with nuts or the like. A latch back plate 89 may optionally be mounted on the inside surface of bottom housing wall 82 to provide reinforcement and a rigid surface against which a nut may be screwed, or a rivet may be pulled.

6 and 10 illustrate how the handle base 36 and latch 90 are mounted in such a way as to avoid interfering with the overlapping engagement of the two flanges 44,84. Both latches 90, 90' function identically and engage the rest of the case 30 in the same manner, so a description of one latch can be used to describe both latches. Since the pin 90 is mounted on the bottom shell wall 82 somewhat away from the bottom shell flange 84, a space is provided between the pin 90 and the bottom shell flange 84, and the cover shell flange 44 can slide inserted into this space. Thus, when the box 30 is fully closed, the lid flange 44 rests against the bottom flange 84 and the lid peripheral edge 48 rests against the bottom wall 82 (as seen in FIG. 5 ) without any movement from the latch. 90 interference. In this way, when the case 30 is closed, a portion of the cover flange 44 is smoothly sandwiched between the bottom of the latch 90 and a portion of the bottom flange 84 . Thus, the present invention allows the housings 40 , 80 to be bolted together without any type of protrusion or hole having to pass through the bottom housing flange 84 or the lid housing flange 44 .

Figures 2, 3 and 10 show the case 30 closed with the handle 34 and handle base 36 positioned between the two latches 90, 90'. The inner ends of the latches 90, 90' are substantially aligned with the corresponding outer ends of the handle guards 35, 35'. The handle bezels 35, 35' have a space between a portion of each handle bezel 35, 35' and the cover flange 44, so that when the case 30 is closed, one of each latch 90, 90' is shortened. A portion of the baffle fits under a portion of a corresponding baffle 35, 35', as shown in detail in FIG. 10 . Thus, the case 30 can be fully closed with the cover flange 44 outside and surrounding the bottom flange 84 and the latches 90, 90' also accessible outside the case 30, as shown in FIG.

Conventional lift bar latches known in the art are "bottom mounted", ie they are attached to the luggage case by means of screws or rivets that pass through the bottom plate of the latch and into the frame of the luggage case. Similarly, most latch levers are usually "bottom locked". Bottom locking snib bars utilize a locking cylinder that passes through the bottom plate of the snib bar and through the frame of at least one housing in order to lock the latch to the frame and thereby secure the housings together.

The latch 90 of the present invention shown enlarged in Figures 9 and 10 is similar in general operation to the lifting lever latches known in the art, but differs from known devices in that it is modified to be side mounted, Rather than being bottom mounted, it only locks to its own base plate 92 and not to a frame member. As previously mentioned, one side of the plug 90 is attached to the wall 82 of the bottom housing 80 ; (Installing latch 90 to housing 80 according to standard methods may include more directly attaching base plate 92 to base housing flange 84 with screws or bolts.)

Similarly, latch 90 is side-attached. The latch 90 has a hooked pin 94 extending from the side of the latch 90 . The hooked pin 94 engages with the catch 39 protruding from the handle base 36; when the case 30 is closed, the engagement of the pin 94 with the catch 39 (together with the hinges 71, 71') is used to hold the lid Shell 40 is securely latched to bottom shell 80 . Thus, the latch 90 is characterized as being side-attached.

Continuing to refer to FIGS. 9 and 10 , which illustrate the configuration of the latch 90 . The latch 90 has a body 93 which is securely attached to the wall 82 of the bottom housing 80 . The main body 93 has a rail 95 on which the reciprocating member 96 can slide, that is, the reciprocating member 96 is slidably mounted on the rail 95 . The handle bar 98 can be lifted and lowered by hand to disengage and engage the latch 90. A handle pivot 98 is pivotally connected to a reciprocating member 96 by means of an axle post 97 . Axle 97 extends through handle bar 98 and shuttle 96, and is preferably also positioned through a slot in track 95 so that shuttle 96 can be in a horizontal direction (e.g., parallel to bottom housing flange 84) It slides back and forth on track 95, but is restricted from moving up and down (perpendicular to bottom case flange 84). Hooked pin 94 is rigidly mounted or integrally mounted to shuttle member 96 and extends transversely therefrom. The handle bar 98 is also rotatably connected to the main body 93 by a connecting arm 99, the ends of which are pivotally connected to the handle bar 98 and the body 93, respectively. The protrusion 101 and the pawl 102 are pivotally attached to the distal end of the handle bar 98 . When the case 30 is closed, the handle bar 98 may be depressed so that the pawl 102 engages the iron horn 100 . A resilient member 104 (such as a spring or the like) connects the reciprocating member 96 to the main body 93 and biases the reciprocating member 96 toward the distal end of the main body 93 (eg, toward the iron horn 100).

These figures show the components of the latch and handle assembly as they are just prior to closing the case 30 in order to understand the action of the latch 90 . The latch 90 is open and the handle bar 98 is raised. When the case 30 is fully closed, the peripheral edge 48 of the cover flange 44 preferably rests against the outside surface of the bottom wall 82 and a portion of the latch 90 moves below the protruding portion of the handle flap 35 . When the case 30 was closed, the handle bar 98 was pressed down; when the handle bar was pushed downward toward the cover flange 44, it pivoted relative to the shaft post 97 and the connecting arm 99 (while the connecting arm 99 also pivoted Swing along its connecting part with the main body 93). Simultaneously, the reciprocating member 96 slides on the track 95 , overcoming the tension of the elastic member 104 , while the entire handle bar 98 moves downward and slightly towards the proximal end of the main body 93 , eg towards the handle 34 .

When the handle bar 98 is fully depressed, it is substantially parallel to the floor 92 of the body 93 and parallel to the flanges 44, 84 (which now overlap each other). Shuttle 96 is translated to its position closest to handle fence 35 , which causes hooked pin 94 to engage catch 39 . Hooked pin 94 is inserted between clip 39 and cover housing wall 42 to latch housings 40, 80 together by connecting their respective wall portions 42, 82. The engagement of the claws 102 with the iron horns 100 makes the latch secure. This engagement can be double secured by the action of the cylinder of the key lock 103 on the handle bar 98, if desired. When the key lock 103 is engaged, it secures the handle bar 98 on the base plate 92, which prevents the handle bar 98 from being lifted and the hooked pin 94 disengaged from the catch 39. The latch 90 of the present invention differs from prior lifting handle latches in that the handle bar 98 locks directly to the base plate 92, and only to the base plate 92, rather than to the base shell flange 84, which allows the The housing flange 44 is inserted between the latch 90 and the flange 84 . The latches 90, 90' are preferably at least partially recessed into the passages formed by the walls 42, 82 and the cover flange 44 when the case 30 is closed and the latch handle bar 98 is depressed.

The latching of the housings 40, 80 is accomplished by repeating the latching process in reverse order. First, the protruding part 101 is lifted to release the claw 102 from the iron angle 100 . A slightly upward pulling protrusion on the handle bar 98 pulls the handle bar 98 out of its closed position, at this time, the energy stored in the stretched elastic member 104 is released, causing the reciprocating movement member 96 is pulled rapidly along track 95 toward the distal end of latch 90, and as a result, handle bar 98 rotates about axle post 97 and connecting arm 99, and "pops" upward to a fully extended position, as shown in FIG. . The resilient member 104 pulls the shuttle 96 to its furthest position (away from the handle 34 ), which causes a concomitant movement of the hooked pin 94 , thus disengaging it from the catch 39 . The user can then grasp the handle 34, lift the lid shell 40, and swing it up and away from the bottom shell 80 to open the case 30.

However, the lift handle 90 is essentially independent of any particular portion of either housing 40 , 80 . It can be locked on itself (instead of being locked to an opposing housing member) with the iron angle 100 and the pawl 102, and it engages the clip 39 which can be mounted vertically on the opposite anywhere on the housing. As a result, the function of the latch is achieved with a minimum of penetration into the housing to weaken it.

Figures 2, 7 and 10 illustrate an auxiliary system used to guide the proper alignment of the two shells 40, 80 when closing the case 30. Rigidly projecting from the sides of the handle base 36 is one or more alignment pins 110, 110'. Corresponding pin holes 111 , 111 ′ are provided in bottom housing wall 82 . The pins 110, 110' are aligned with the pin holes 111, 111' and during closing of the case 30, the pins 110, 110 are inserted into the holes 111, 111'. The engagement of the pins 110, 110' with the pin holes 111, 111' helps prevent parallel relative movement of the overlapping flanges 44, 84 when the case 30 is closed. The pins 110, 110' also help transmit the shear force between the two shells 40, 80 of the case 30; The contact of the sump walls 82 transfers the force of the load between the walls 42 , 82 .

Thus, it can be seen that the manner and means of latching the housings 40, 80 of the present invention provide secure closure of the case 30 without the need for any holes, bolts, screws, clips or other parts to penetrate the flanges. 44, 84. This does not require any holes through the flanges 44, 84 or any device to be mounted on the flanges 44, 84 is advantageous, resulting in a stronger flange, and overlapping of the flanges without hindrance, making the case 30 closes smoothly and unhindered. In addition, limiting the attachment of the latches 90, 90' and handles 34 to the outwardly facing surfaces of the walls 42, 82, respectively, helps simplify factory assembly. The housings 40, 80 are conveniently fixed on a horizontal work surface (such as in FIG. 7 ), and various screw fasteners are inserted from above to install each hardware component to the wall 42 in a "top-down" manner. , 82 on. Since there are no parts to be added to the flanges 44, 84, no complicated positioning means are required to vertically fix the housing 40, 80 and to rotate and/or reposition the housing to secure the fasteners. Insert through these flanges.

As shown in Figures 4-6, the housing 40, 80 can be molded with one or more shock-absorbing narrow strip channels 50, 50', which are shallow channels or not deep grooves, adjacent to the flange 46 or 86 extends around the perimeter of the housing 40,80. Narrow channels 50, 50' are optional and are used to improve the appearance of the housing. Narrow channels 50, 50' accommodate and retain shock absorbing narrow strips. Shock absorbing straps (not shown) are elastic straps or cords that are wrapped around the perimeter of the luggage case shell to absorb the normal wear and tear that some luggage cases are subject to. The shock-absorbing strips are often colored in a color that contrasts with the color of the housing 40 or 80 or is pleasing, so that these strips serve two purposes: to improve the aesthetics of the case 30, and prolong its service life. The inventive process also enhances the ability to mold other desired functional and/or aesthetic features into the housing in the vicinity of the housing flanges 46,86.

Known pressure forming or vacuum forming devices and systems are not capable of producing the described luggage device. In existing systems, the wall portions 42, 82 and/or the flanges 44, 84 are formed in the configuration shown (i.e., the wall portions 42, 82 project substantially perpendicularly inwardly from the side portions 83a, 83b). May seriously hinder the removal of the molded product from the mold. The wall portions 42, 82 may catch, or"hang"over, corresponding annular shoulders of the mold forming the wall parts, locking the product into the mold.

Figures 11-15 show the main components of the invented device implementing the process of the invention. The apparatus includes an upper platen assembly 200 and a lower platen assembly 240 which are disposed in parallel, preferably horizontal, relation to each other, one above the other. A hydraulic system or other known system allows upper die plate assembly 200 and lower die plate assembly 240 to move vertically relative to each other, eg, closer together or farther apart. Known techniques allow controlled adjustment of the distance between the platen assemblies 200, 240 by moving the upper platen assembly 200 or the lower platen assembly 240, or both. Accordingly, the compression plate assemblies 200, 240 may be substantially separated, or they may be brought into contact. For example, FIGS. 11 and 13 show the compression plate assemblies 200, 240 in a far apart position, while FIG. 14 shows the compression plate assemblies 200, 240 drawn together.

In the preferred embodiment, the upper platen assembly 200 includes a vacuum box 202 and a shell mold 206 . As generally shown, housing mold 206 has an outer surface 207 and an inner surface 208; the latter being the mold surface for forming the shape of the product being molded. In the present invention, the shell mold 206 is removable and replaceable so that the apparatus can be used to make luggage shells, or other products, with virtually no restrictions on the variety of shapes, surface finishes, and surface textures. The function of the outer surface 207 of the housing mold 206 is to form and enclose the evacuated space 210 in conjunction with the vacuum box 202 and substantially surround it. The shell mold 206 is in sealing contact with the vacuum box 202 . The vacuum box 202 has one or more vacuum holes 205 connected to corresponding vacuum lines 204 . Vacuum line 204 is in fluid communication with known pumping means. A pump (not shown) is used to evacuate air (or other gas) from the evacuated space 210 in the vacuum box 202 .

The evacuated space 210 is defined by the components of the upper platen assembly 200 such that the evacuated space 210 can be sealed and isolated from the surrounding atmosphere. FIGS. 11 , 13 and 14 show that this can be achieved by placing the shell mold 206 in sealing contact with the vacuum box body 202 . The vacuum box body 202 is sealed with the outer surface 207 of the housing mold 206 by a gasket. Upper platen assembly 200 and vacuum cassette 202 are adapted to function with different types of housing molds 206 . In the embodiment shown in FIGS. 11-15, the shell mold 206 is a concave or "female" mold used to shape the luggage shell. The final shape and surface finish (smooth, grained, stippled, etc.) of the shell being molded is determined by the mold surface 208 of the shell mold 206 . The mold space 212 is in a concave portion of the housing mold 206 such that the mold space 212 is partially formed.

Referring to Figures 13 and 14, the shell mold 206 is porous throughout with a plurality of vacuum holes (not shown), the holes being more or less evenly distributed on the shell mold 206, substantially in accordance with known techniques. These holes allow air to flow from the mold space 212 into the evacuated space 210 . During molding, a pressure differential developed across the housing mold 206 exerts a force on the heated sheet of housing material 216 against the mold surface 208 . This pressure differential is typically due to a raised air pressure in the mold space 212 and a lowered air pressure in the evacuated space 210 . Additionally, the mold space 212 may be pressurized without simultaneously depressurizing the evacuated space 210, or, more generally, the alternative may be to evacuate the evacuated space 210 without pressurizing the mold space 212 at all.

In a preferred embodiment, sheet 216 is constructed of ABS plastic. Alternative embodiments may utilize polypropylene sheets. Other thermoplastic materials may also be used, but with varying degrees of success. The preferred differential pressure is between approximately 35p.s.i. and 40p.s.i., with a maximum limit of approximately 125p.s.i. A differential pressure below 35p.s.i. must be used at the same time as a plastic with an extremely low melt flow index; however, low melting Flow index has an adverse effect on other key material properties such as impact strength and flexural modulus.

The hold-down template assembly 240 includes a support box 242 that supports a seal plate 244 and at least one pinch-off plate 246 on the seal plate 244 . An optional sealing key 245 can protrude from the sealing plate 244 and extend over the entire circumference of the sealing plate 244 . Sealing keys 245 correspond to one sealing shoulder 217 in each side draw die 230 , 232 . When the upper die plate assembly 200 and the lower die plate assembly 240 are brought into contact with each other, the sealing key 245 can contact the underside of the side drawing dies 230, 232 and engage the shoulder 217, as shown in FIG. 14 . Housing mold 206 , side pull molds 230 , 232 and sealing plate 244 seal mold space 212 and substantially completely enclose mold space 212 when sealing key 245 substantially abuts shoulder 217 .

At least one pneumatic line 248 supplies gas (eg, air) to the mold space 212 . A pump (not shown) pumps air or other suitable gas through air pressure line 248 to increase the air pressure in mold space 212. Pneumatic line 248 may pass through support box 242 and seal plate 244 via injection hole 249 at mold space 212 . Depending on the specific configuration of the pinch-off plate 246, the air pressure line 248 may also pass through the pinch-off plate.

Corner cooling plugs 250, 250', 250", 250'' are above the pinch-off plate 246, and these plugs protrude from the seal plate 244 when the two platen assemblies 200, 240 are pressed together, and Occupies a position in the mold space 212. For ease of operation, the corner plugs 250, 250', 250", 250'' can be controllably moved up and down relative to the sealing plate 244 so that they can be alternately retracted into the support box 242 and protrude outwards from the support box (by passing through the sealing holes in the sealing plate 244 and the pinch-off plate 246). Corner cooling plugs 250, 250', 250", 250'' are used to cool and shape preselected localized segments of the heated sheet 216 prior to pressure differential formation. In the illustrated embodiment In this case, the corner plugs 250, 250', 250", 250'' are shaped to provide a convex or "male" mold for the corners of the housing prior to final molding in the differential forming process. initial shape. The corner cooling plugs 250, 250', 250", 250'' are in fluid communication with a source of cooling fluid (not shown), which is circulated to and through the plugs via cooling lines 252.

In a preferred embodiment, the pinch-off plate 246 is disposed on and parallel to the sealing plate 244 . The outer edge 247 of the pinch-off plate 246 is beveled at an obtuse angle such that the edge 247 of the pinch-off plate 246 slopes outwardly across its entire perimeter, away from the middle of the plate 246 . When the side drawing dies 230, 232 are moved to their innermost positions prior to creating a pressure differential for vacuum forming and/or pressure forming, the sloped surface of the beveled edge 247 comes into close proximity to the side drawing dies. The position of the lower edge of the inside surface 236,237 of 230,232. During the pressure forming and/or vacuum forming of the luggage shell, the sheet material 216 is placed between the side drawing dies 230 , 232 and the pinch off plates 246 .

In a preferred embodiment, the pinch-off plate 246 is removable from the seal plate 244 . A known hydraulic or other system controls the movement of the pinch off plates 246 . As shown most clearly in Figures 14A and 14B, the pinch-off plate 246 can move up and down a relatively short distance so that it can come into contact with the seal plate 244, or move away from the seal plate 244 in parallel, and in the seal plate 244. 244 above. Moving the pinch off plate 246 upwardly into contact with the side drawing dies 230, 232 cuts off or "pinches off" the offcut portion 222 of the sheet of thermoplastic material 216, leaving a neat, uniform, trimmed profile along the formed shell. edge.

At least one, but preferably two or four side drawing dies 230 , 232 are provided below the housing die 206 and above the sealing plate 244 . Implementation of the invention includes movement of the side pull dies 230,232. The side drawing dies 230 , 232 may move separately from either die plate assembly 200 , 240 . As shown most clearly in Figures 12 and 15, side draw dies 230, 232 are laterally movable moldings which are used to shape the final product. The side pull dies 230, 232 can be moved radially inward and outward from the center of the pinch-off plate 246 by a hydraulic system, pneumatic system, or mechanical jack system, or the like, as indicated by the directional arrows in FIG. 12 . FIG. 12 shows the sidedraw dies 230 , 232 in a retracted state, withdrawn outwardly by the pinch-off plates 246 .

Controllable hydraulics are used to simultaneously translate the sidedraw dies 230, 232 inwardly toward or outwardly away from the pinch-off plates 246, as indicated by the directional arrows and dashed lines in FIGS. 11 and 12 . FIG. 15 shows the side pull dies 230 , 232 moved to a position closer to the pinch off plate 246 . As shown in Figures 13, 14, 14A and 14B, in a preferred embodiment, when the side pull molds 230, 232 are extended to the closed position, their inner side surfaces 236, 237 pass over the mold inner side of the housing mold 206. Surface 208 protrudes and projects inwardly into mold space 212 . As shown in FIG. 11 , the side pull dies can be retracted to a fully open condition and the inside surfaces 236 , 237 are drawn outwardly, past the inside surface 208 of the die. In their fully "extended" state or "closed" state, the ends of the side pull dies 230, 232 actually contact each other so that the dies 230, 232 form a ring around the pinch-off plate 246, and the ring Substantially surrounds and forms the perimeter of the molded product.

These figures show an embodiment of the invention employing two side dies 230, 232, each having two vertical legs. The movement of each side drawing die 230, 232 is substantially linear along the diagonal axis, as shown in FIG. The diagonal axis of translational motion of each die may be roughly described as a straight line running through the center of the pinch off plate 246 and through the corner of the plate adjacent the respective die 230 or 232 . As each plate 230, 232 moves inwardly, its vertical legs move and mold two adjacent sides of the molded product.

Those skilled in the art will appreciate that the number of sidedraw dies employed in the present invention can vary and can be used to customize the equipment for a particular molding project. For example, if it is desired to use sidedraw dies to create steep-sided recesses or deep pockets (such as wheel wells) on the side of a molded housing, it is best to use four independently movable sidedraw dies , one mold for one side of the shell. Using four side draw dies, although more complex and expensive, allows each die to involve vertically a respective single side of the luggage case to form vertical recesses into the sides of the shell. (In the variant of the invention employing two side-draw dies, each die obliquely engages both sides of the shell simultaneously, limiting its ability to produce structures that enter perpendicularly into any given side.) However, the present invention A further embodiment of the present invention may employ a side draw die where it is not necessary to form the entire perimeter of the final product, but only one or two sides.

The side pull dies 230, 232 are also independently movable up and down between the two platen assemblies 200, 240. For ease of drawing, for example, FIG. 11 shows the side pull dies 230 , 232 in a lowered position, nearly in contact with the sealing plate 244 . FIG. 13 shows the side pull molds 230 , 232 raised so that there is a sealing contact with the outer periphery of the housing mold 206 .

The manufacturing apparatus of the present invention shown in the figure has a concave shell mold 206 installed in the upper die plate assembly 200 , and a pinch-off plate 246 and a sealing plate 244 disposed in the lower die plate assembly 240 . However, it should be readily understood that the entire device may be reversed as to its function or position without impairing its function and without departing from the scope of the present invention. For example, the lower die plate assembly 240 may additionally include a housing mold and a vacuum box forming an evacuated space, while the upper die plate assembly 200 may consist of a sealing plate positioned under a support box with a A pinch-off plate suspended by the seal plate. Such an "upside down" embodiment may interfere with the use of cooling plugs in the corners, but would otherwise meet the objectives and advantages of the present invention. Similarly, acceptable alternative embodiments of the present invention may include the use of "male" shell molds, whereby a force is applied to the thermoplastic sheet against a concave mold.

The practice of the process of the present invention and some of its advantages can now be described. Referring to Figures 11 and 12, these figures show the apparatus of the present invention at the very beginning of a production cycle. In FIGS. 11 and 12 , the upper die plate assembly 200 is in a raised position to provide a working space between it and the lower die plate assembly 240 . For pictorial clarity, FIG. 11 shows a large separation distance between the upper die plate assembly 200 and the lower die plate assembly 240 . In practice, the compression plate assemblies 200, 240 may actually be separated by only a relatively small distance, just enough to allow a sheet of thermoplastic material to be inserted therein (see Fig. 13).

The contact between the vacuum box 202 and the outer surface 207 of the housing mold 206 is sealed against air leakage. The contact between the sealing plate 244 and the support box 242 is likewise sealed. The selected side pull dies 230, 232 are loaded in the retracted state (dashed lines in FIGS. 11, 12 and 13), but then moved to its extended position (dashed lines in FIGS. 14 and 11) . Figure 15 shows that the molds 230, 232 have just not reached the inwardly fully extended position; in the fully inwardly extended position, the respective distal ends of the legs of the molds 230, 232 actually touch around the formed sheet 216 , forming a circle. Cooling water or other cooling fluid is pumped to the corner plugs 250, 250', 250", 250'' through cooling line 252 and is continuously recirculated in order to transfer heat from the The heated and softened thermoplastic sheet 216 is carried away. Corner cooling plugs 250, 250', 250", 250'' are located in a position above the pinch-off plate 246 as shown in Figure 11, or, alternatively, It can be positioned below the pinch off plate 246, but it is easily moved up to the position shown in FIG.

A sheet of thermoplastic material 216 is heated to make it malleable and compressible. The sheet 216 is held around its edges by control clips 213, 213' and moved (up and down and reciprocating) as shown in FIG. The control clip 213 is used to fix and maintain the length of the outer edge of the sheet 216 . As also shown in FIG. 13, the two compression plate assemblies 200, 240 are separated and the side pull dies 230, 232 are positioned so that the hot, deformable thermoplastic material sheet 216 can be moved between the compression plate assemblies 200, 240. of a location. The sheet 216 is placed centrally above the pinch off plate 246, above the corner cooling plugs 250, 250', 250", 250''', and below the shell mold 206 and side pull molds 230, 232 .

After the heated sheet 216 has been moved into place, the sheet is connected to the cooling plugs 250, 250' at the corners by lowering the sheet 216, by raising the plug, or by raising the entire lower die plate assembly 240. , 250″, 250 surface contact. At this time, the plugs 250, 250′, 250″, 250 play a role in supporting the sheet 216 partly. As shown in FIG. 13, the portion in contact with the cooling plugs 250, 250', 250", 250'' of the corners supports the sheet 216, which softens at the elevated temperature, and does not support the sheet elsewhere. When the sheet 216 is initially placed between the compression plate assemblies 200, 240, the sheet may be substantially planar, but the elevated temperature makes it moldable. Due to gravity, the sheet's The central portion 219 that is not supported between the plugs 250, 250', 250", 250'' may hang or hang down, tending to take the shape of a depending line of suspension in the section taken between the plugs. Importantly, as the central portion 219 of the sheet 216 hangs down, it is also pulled on the trim portion 222 of the sheet 216 on the outside of the plug 250, 250', 250", 250'', thereby bringing the sheet up and extend toward the center of the pinch-off plate 246 on the plug, as shown by the directional arrows in Figure 13.In this way, the thermoplastic material sheet is moved from the part of the sheet 216 that may become waste to the section where the sheet is The part that is made into the final product.

A disadvantage of many typical vacuum-formed or pressure-formed articles is that the corners of the exterior are weak; the corners of typical luggage shells in the state of the art are often crushed or collapsed under impact loads. This weakness is at least in part due to conventional vacuum forming or pressure forming processes reducing the amount of housing material at the corners of the housing. Applying force to the softened thermoplastic sheet fully into the extreme corners of the housing mold will stretch the sheet near the corners, resulting in a thinner, and therefore weaker, sheet at these locations. Less extension of the sheet is required in order to push the main portion of the sheet against the generally flat portion of the mold to form the panel portion of the housing. As a result, conventional differential formed luggage shells are often thinnest at the corners and thickest at the main panel sections. This is the opposite of optimal because the corners of the shell experience the greatest stress, so ideally these should be the thickest and strongest parts of the shell.

Another disadvantage inherent in known differential pressure molding methods is that all portions of the sheet of material must be extended to a greater or lesser extent in order to compress the sheet into the shell. Since the total surface area of the formed shell in three degrees of freedom is larger than the original surface area of the planar sheet material used to form the shell, and since a fixed volume of thermoplastic The material can be pressed into the die with necessarily a net reduction in the average thickness of the sheet with the application of force to the sheet against the die.

Here, therefore, the advantages of the present invention are evident. It is known that, in the technique of differential pressure forming, a plug is provided to help form a sheet of softened thermoplastic material just before differential pressure is applied to mold the product. In the present invention corner plugs 250, 250', 250", 250'' are shaped and positioned to assist only those portions of the tab 216 that will form the corners of the housing. , perform preforming, and actively cool these parts. The cooling plugs 250, 250', 250 ", 250'' at the corners not only help the sheet 216 to form, but also reduce the cooling of those parts of the sheet 216 corresponding to the corners of the housing. extend. When the hot, softened foil 216 is moved to the corner cooling plugs 250, 250', 250", 250'', those parts of the foil 216 that are actually in contact with these plugs are significantly cooled, reducing the Their plasticity. This reduced plasticity has suppressed the undesired extension at these specific parts of the sheet 216. When the sheet 216 was formed into a shell, the cooled part was less affected than in the prior art. Therefore, a greater thickness is maintained compared to other parts of the shell. In the present invention, those parts of the sheet 216 that form the corners of the luggage case are cooled by the plugs, thereby providing a thicker strength Tall housing corners.

Figure 13 also shows that, in the present invention, most of the plastic foil 216, specifically the cooling plugs at the corners, can be tolerated for a short time before the differential pressure used to shape a shell is applied. 250, 250', 250", 250'' between those portions of the overhang. This underhang of the sheet 216 causes all sections of the sheet 216 to be moderately pre-stretched except the corners. Thus, the present invention effectively places the sheet 216 The central section 219 of the present invention has carried out pre-stretching, and these parts will form the bottom 81 of shell or panel part, and the product shell of these parts is thinner and can be accepted.Therefore, an advantage of the present invention is that, in actual vacuum forming or prior to pressure forming, the hot softened sheet 216 is cooled at those portions forming the corners of the shell and pre-stretched at those portions forming the shell panels, forming stronger corners with Vacuum-formed shells with slightly thinner panels.

Another advantage of the present invention is that it increases the net volume of thermoplastic material that can be molded into the final product. This increase is due to the increased efficiency of material utilization without requiring a net increase in actual material.

Some shell material will be overhanged and outwardly hung by the corner plugs 250, 250', 250", 250'', and gradually sandwiched between the shell mold 206 and the seal plate 244. However, in shell material The tab 216 is allowed to sag between the corner plugs 250, 250', 250", 250''' before being sandwiched between the underside surfaces of the housing molds 230, 232 and the seal plate 244, as previously described. Due to this drooping, the offcut portion 222 of the sheet is extended because the edge of the sheet 216 is held by the control clips 213,213. This extension manifests itself as a somewhat inward sliding of the tab 216 over the top of the plug 250, 250', 250", 250'', as indicated by the directional arrows in Figure 13. This sliding and extending causes the thermoplastic material to A net volume moves radially inwardly from the scrap portion 222 of the sheet 216 into the boundary portion. Material can also move up and over the corner plugs 250, 250′, 250″, 250′′, sliding through these plugs into and Towards the central portion 219 . A net increase in the volume of the portion of the thermoplastic material sheet 216 facing the mold 206 is achieved; the advantageous result of this movement of the thermoplastic material is that more material is available from a given sheet 216 to face the mold 206. The mold 206 is pressed. A relatively reduced volume of material remains in the scrap portion 222 of the sheet.

Due to this increase in the volume of material available to mold against the mold 206, the undesired stretching of the flakes 216 to fit the mold surface 208 (especially the corners) is reduced. The greater volume of material available creates thicker molded housing walls, producing a relatively stronger housing. Thus, the performance of the final housing product is enhanced without the need for additional material.

See Figure 13. Once the sheet 216 has been pre-extended to the optimum state as described above, and shortly after the sheet 216 comes into contact with the corner plugs, move the seal plate 244 together with the side pull dies 230, 232 (perhaps by moving the platen assembly 200, 240 or both), the waste or scrap portion 222 of the sheet 216 is clamped between the sealing key 245 and the underside surface of the side drawing die 230, 232. Clamping the seal plate 244 with the sidedraw dies 230, 232 provides an annular seal around the die space 212, with the scrap 222 serving as a temporary gasket. (Alternative methods can be used to seal between the side drawing dies 230, 232 and the sealing plate 244, but the overall purpose is to seal and substantially completely enclose the die space 212.) In a preferred embodiment, during the process At this stage, the shell mold 206 , the seal plate 244 and the side drawing molds 230 , 232 completely surround the mold space 212 . The platen assemblies 200 , 240 may be releasably locked together to ensure a proper seal surrounding the mold space 212 .

Subsequently, increasing the air pressure to the mold space 212 and evacuating the evacuation space 210 are started. Air or an inert gas is rapidly pumped into the mold space 212 through the air pressure line 248 while air is drawn out of the evacuated space 210 through the vacuum line 204 . The result is a sudden drop in pressure in the evacuated cavity 210 and an increase in pressure in the mold space 212 . These changes in pressure create a pressure differential across the housing mold 206 that causes gas to flow from the mold space 212 through the vacuum holes in the housing mold 206 to the evacuated cavity 210 . The pressure differential across the housing mold 206 and the forced flow of air through the holes penetrating the housing mold 206 creates a corresponding fluid pressure differential across the housing 216 itself, essentially according to principles known in the art. This pressure differential is due to the lower pressure between housing 216 and housing mold 206 than the pressure between housing 216 and seal plate 244 . This pressure differential quickly presses the softened sheet 216 tightly against the inside surface 208 of the shell mold 206, as shown in FIG. 14 . Applying pressure to the sheet 216 against the shell mold 206 using a pressure differential is the "differential pressure forming" step of the process. Maintaining this pressure differential for a period of time ensures that every feature of the inner mold surface 208 is fully applied to the shell 216 .

Beginning to apply the pressure differential and apply pressure to the shell 216 against the shell die 206 while the side pull dies 230, 232 are in an extended state close the side pull dies 230, 232 towards the pinch off plate 246 and form a complete A side draw die surrounds the perimeter of die space 212 as shown in FIGS. 13 and 14 .

FIG. 14 shows that the increased pressure in the die space 212 exerts a force on the edge of the sheet 216 against the inside surfaces 236 , 237 of the side drawing dies 230 , 232 . The inner side surfaces 236, 237 of the side drawing dies 230, 232 may be shaped or configured such that molding can be performed by applying pressure to the edge portions of the sheet 216 against these inner sides. These inner side surfaces 236, 237 are preferably removably mounted to the inner ends of their respective sidedraw molds 230, 232, and these inner side surfaces may be bolted to the molds 230, 232 or slidably attached (e.g. keyway lock) plate or block on mold 230,232. Since the inner side surfaces 236, 237 are preferably removable, they can be replaced independently of the side pull dies 230, 232 and independent of the main housing die 206.

Thus, the present invention makes it possible to change the appearance, shape, and even dimensions (eg, depth) of the molded shell without changing the entire shell mold 206 . The side pull molds 230, 232 are also replaceable with respect to the housing mold 206, but the preferred embodiment allows the user to customize or modify his product by simply replacing the inside surfaces 236, 237. Special individual inner side surfaces 230, 232 can be configured to provide shock-absorbing narrow channels, and/or localized markings for hardware installation, and/or aesthetically pleasing lines, marking strings, bumps, and/or The analogue is molded onto the housing of the final product. Likewise, the inner side surfaces 230, 232 can be configured to mold desired structural features, such as wheel wells and/or handle wells, into the final housing.

Similarly, the various inner side surface sets 230, 232 that may be used with a particular corresponding side draw die 230, 232 and a given housing die 206 may be of different sizes. The overall depth of the molded container or shell can be changed from cycle to cycle by replacing a narrower (eg shorter) or wider inner surface part without the need to change or replace the shell mold 206 Or side pull dies 230,232. Thus, an advantage of the present invention is that the independent replacement of the inner side surfaces 236, 237 allows the use of a relatively limited number of different shell molds 206 and side pull molds 230, 232 to alter the appearance and/or configuration of the finished shell. .

FIG. 14A is an enlarged cross-sectional view showing details of molding edge 220 of sheet 216 with a side pull die 232. FIG. The side draw die 232 extends inwardly, preferably over the inside surface 208 of the housing die 206, and molds the edge portion 220 of the sheet 216 accordingly. Side drawing die 232 can shape edge 220 to produce a wall portion 42 and a flange 44, as those parts similarly shown in FIGS. 4 and 5 (respectively labeled 42 or 82, and 44 or 84). The main or central portion of the sheet material 216 shown in FIG. 14A makes up the bulk of the housing 40 or 80 shown in FIGS. 4 and 5 . Thus, the side draw molds 230, 232 mold the shell 40 or 80 of the preferred embodiment luggage case, providing the wall portions 42, 82 and flanges 44, 84 formed by FIGS. 1-8 and previously described. The resulting frame features, as well as other housing features, such as shock-absorbing narrow channels and the like.

Like this, side drawing dies 230,232 mold the edge portions of sheet 216 which gradually include the frame portion of the perimeter of the finished shell (and side drawing dies 230,232 may also be configured to also mold the sides of the shell or other partial forming). As pressure is applied to the hot sheet 216 against the inside surface of the shell mold 206, it simultaneously exerts force against the side drawing molds 230, 232, which protrude inwardly into the mold space 212. The portion of sheet 216 located between dies 230, 232 and pinch-off plate 246 is deformed from a planar sheet to a shape having a cross-section as shown at 14 and 14A. Considering FIGS. 4 and 8 in conjunction with FIG. 14, it is shown how the edges of the sheet 216 are molded using side draw dies 230, 232 to form the flanges 44, 84 and wall portions 42, 82 of the finished housing 40, 80. . FIG. 14A also provides details of the sealing key 245 which crimps the waste or scrap portion 222 of the sheet 216 against the shoulder 217 in the sidedraw die 232.

After the sidedraw die plates 230, 232 are moved to the extended position shown in FIGS. 14 and 14A to shape the edge 220 of the sheet 216, the sheet 216 is maintained in the configuration of FIG. 14 for a short period of time. Subsequently, an optional feature of the present invention may be performed to remove offcut portions 222 from the edges 220 of the sheet 216 . It is known in the art to cut excess housing material from the molded housing in a separate process step using a band saw or similar tool after differential forming has been completed. 14, 14A and 14B taken together illustrate how the sheet 216 is severed using the pinch off plate 246. 14A and 14B are enlarged cross-sectional views of that portion of FIG. 14 showing sidedraw die 232 forming edge 220 of sheet 216, inwardly beyond housing die 206, to abut the vicinity of pinch-off plate 246 , or even slightly in contact with the pinch-off plate 246 . In one direction perpendicular to the seal plate 244, as indicated by the directional arrow in FIG. 14A, the pinch-off plate 246 is movable, eg, hydraulically. Typically, the pinch-off plates 246 are in a parallel position and contact the underlying seal plate 244 on which the pinch-off plates 246 rest. A powered mechanism (not shown) may be located just below the seal plate 244, in the middle of the support box 242, extending through the seal plate 244 to the pinch-off plate 246.

After differential pressure forming of the sheet 216 against the shell die 206 and the side draw dies 230, 232 (see FIG. 14A ), the pinch-off plate 246 is moved a small distance up and away from the seal plate 244 to the end of FIG. 14B . location shown. Movement of the pinch-off plates 246 is preferably performed just before the pressure is relieved from within the mold space 212 and the pressure differential across the housing mold 206 is terminated. Thus, the pressure differential holds tab 216 in place during the pinch off process. FIG. 14B shows that the movement of the pinch plate 246 pinches the sheet 216 between the sloped surface 247 of the flat plate 246 and the lower edge of the side drawing die 232 . The pinch-off plate 246 may be brought into contact with the die 232, in which case the web 216 may be severed between the two contacting parts 232,246. In this way, the side pull die 232 is used as a kind of immobile cutting block against which the pinch off plate 2546 can act. In this way, the pinch-off plate 246 separates the scrap 222 (eg, the portion of the sheet 216 below the side-draw die 232 ) from the portion of the sheet 216 (that is above the sloped surface 247 of the pinch-off plate 246 and in the housing die 206 ). 216) the edges are cut off. Alternatively, the surface 247 of the plate 246 can be moved close to the edge of the mold 232, but not in contact with it, as shown in FIG. 14B, to compress the sheet 216 without completely severing it. This creates a permanent crease in the tab 216, making it easier to separate the waste material from the housing later. Pinching off, completely cutting off or creasing the sheet 216 provides a clean, uniform cut of the sheet 216 between the edge 220 and the trim 222 . Such a cut should be uniform as it occurs at the location along which it evolves the peripheral edge 48 or 88 of the housing 40 or 80 as shown in FIGS. 1 , 2 and 4 .

An advantage of the present invention is that its peripheral edges 48, 88 are exposed, not surrounded by an expensive and bulky metal frame, but are exposed, making it economical, aesthetically pleasing, and easy to close the case. The peripheral edges 48, 88 are preferably ground or machined to a pleasing smoothness, perhaps using a computer-guided trimming tool for this process.

After moving the pinch off plates 246, the sheet 216 is held against the shell mold 206 long enough to allow it to cool and harden, if necessary, in order to sever the sheet 216 (see FIG. 14B). Once the casing sheet 216 is cooled, it loses its plasticity and becomes rigid, taking the general shape and form of the final product.

As already mentioned, the side drawing dies 230, 232 can be moved radially outwardly from the extended position shown in FIGS. 13, 15 and 14 and shown in dashed lines in FIG. The retracted position is shown and shown in phantom in FIG. 13 . While the applied pressure differential secures the sheet 216 against the housing die 206 and inside surfaces 236, 237, as shown in FIG. The compression platen assemblies 200, 240, and move between the compression platen assemblies 200, 240 outwardly from the positions shown in FIGS. 13 and 14 . The side drawing dies 230, 232 are pulled away from the cooled sheet 216 and retracted outwardly to the positions shown in phantom in Figure 13 and in Figures 11 and 12 . Subsequently, the platen assemblies 200, 240 are removed so that the sheet 216, now a molded shell, is removed from the molding apparatus for further processing, hardware and lining, and the like, if desired. things.

It can be observed that the movable side drawing dies 230, 232 allow the shell to substantially form the shell walls 42, 82 which hang inwardly from the shell itself at an angle of approximately ninety degrees, also making it easy to The molded housing is removed from the housing mold 206 . The movable feature of the side pull dies 230, 232 overcomes the disadvantage of the prior art that differential pressure formation of these pronounced protrusions can significantly hinder removal of the molded housing from the housing mold 206. If the side drawing dies 230, 232 cannot move radially outwardly, the annular wall portion 82 of the molded housing 80 may be pressed against the immovable side drawing die, and the wall portion 82 is pressed onto the die, top is locked, and the entire housing may be molded virtually permanently in its own mold. Conversely, if it is not possible to mold a substantially substantially vertically projecting wall portion 82, cantilevered inwardly or outwardly from the main or central portion of the housing, if there is no effective increase in the moment of inertia of the housing, and thus The inability to mold integrally formed frame members virtually precludes the use of differential pressure molding. The present invention overcomes the disadvantages of known systems by allowing integrally formed container frames to be molded, consisting of distinctly protruding walls 82 and flanges 84, while also allowing the integral frame to be The shaped mold parts 230 , 232 are retracted so that the molded container can be separated from the mold 206 .

Although the invention has been described in detail with specific reference to these preferred embodiments, other embodiments can obtain the same effect. Modifications and improvements of the present invention will become apparent to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire publication of the above-mentioned patent is hereby incorporated by reference.

Claims (32)

1. In a differentially formed luggage case with two plastic shells, the two shells being a lid connected pivotally, such as by a hinge or the like, to a bottom shell shells, each shell has a bottom and a plurality of sides extending from the bottom to a flange, the flange of the cover shell roughly corresponds to the flange of the bottom shell, so that when the two shells are put together in a closed state On the other, with their flanges substantially aligned, the two shells form between them an interior space in which clothing and personal effects may be placed, the improvements comprising: a cover flange is offset by the cover and forms a peripheral edge of the cover; a first wall portion connects the cover flange to the cover; a sump flange is offset by the sump and forms a peripheral edge of the sump; a second wall portion connects the bottom case flange to the bottom case; When the two shells are in a closed state, the cover shell flange overlaps with at least a part of the bottom shell flange; and Means are provided on said first wall portion and said second wall portion for releasably connecting said two wall portions together. 2. The device of claim 1, wherein the first wall portion is formed integrally with the cover and is suspended by the cover. 3. The apparatus of claim 2, wherein the first wall portion extends substantially perpendicularly from the cover, generally proximate to the cover flange. 4. The device of claim 1, wherein the second wall portion is integrally formed with the bottom shell and is suspended from the bottom shell. 5. The apparatus of claim 4, wherein the second wall portion extends substantially perpendicularly from the bottom casing, generally proximate the bottom casing flange. 6. The device of claim 2, wherein said cover flange is integrally formed with said first wall portion and extends substantially perpendicularly therefrom. 7. The device of claim 4, wherein said bottom housing flange is formed integrally with said second wall portion and extends obliquely therefrom. 8. The apparatus of claim 7, wherein said lid flange and said bottom flange overlap in a non-parallel relationship when the case is in a closed condition. 9. The device of claim 1, wherein the cover peripheral edge and the bottom casing peripheral edge are exposed. 10. The device of claim 1, wherein said means for releasably connecting comprises a latch means mounted on one of said wall parts, and a latch device mounted in said wall part. Snap-on device on the other. 11. The device of claim 10, wherein said latch means is mounted directly to one of said wall parts by means of a fastener which penetrates said wall from the outside of the bottom shell to its inner space. 12. The device of claim 11, wherein said latch means is spaced from said sump flange. 13. The device of claim 12, wherein the cover flange is slidably inserted between the hook means and the bottom housing flange. 14. The device of claim 13, wherein said latch means is a lift handle latch with a movable hook. 15. The apparatus of claim 14, wherein the lifting handle latch comprises: a bottom plate; a handle; and a key lock; It is characterized in that the handle can be locked to the base plate by means of the key lock. 16. A luggage arrangement comprising: a differentially formed sump comprising a plurality of pan sides; a sump flange formed by said sump sides; a sump wall integrally formed with and suspended from said sump sides substantially adjacent at least a section of said sump flange; and a sump flange integrally formed with and extending from said sump wall; A differentially formed cover housing comprising a plurality of cover shell sides; a cover flange formed by the side of the cover; a cover wall portion integrally formed with and suspended from said cover sides substantially adjacent at least a section of said cover flange; and a cover flange integrally formed with and extending from said cover wall; and Means for releasably connecting said cover to said base; wherein said cover is alignably engaged with said base in a closed state so as to be in said a space is enclosed between the shells; and, when the cover shell is alignably engaged with the bottom shell, the cover shell flange and the bottom shell flange are slidably overlapped together, and the cover shell wall and the bottom shell wall form a channel between at least a section of each of the shell flanges; and, it is characterized in that when the cover shell and the bottom shell In a closed position, said means for releasably connecting is disposed at least partially within said recessed channel. 17. The device of claim 16, wherein said cover wall extends substantially perpendicularly from said cover side, and said base wall extends substantially perpendicularly from said base side. Stretch vertically. 18. The device of claim 17, wherein the cover flange extends substantially perpendicularly from the cover wall. 19. Device according to claim 17, characterized in that, at least approximately to the means for the releasable connection, the sump flange extends obliquely from the sump wall. 20. The device of claim 19, wherein when the cover and the bottom are in a closed state, the flanges of the cover and the flange of the bottom are arranged in a non-parallel manner. The formations are slidably overlapped. 21. The device of claim 20, wherein when the cover and the bottom are in a closed state, the flange of the bottom is between the inner space and the flange of the cover. 22. The apparatus of claim 16, further comprising handle means attached to said cover housing wall. 23. The device of claim 16, wherein said means for releasably connecting comprises at least one latch means mounted on said bottom housing wall, and at least one latch means mounted on said cover housing wall. At least one corresponding engaging device on the part. 24. The apparatus of claim 23, wherein said latch means is spaced from said bottom housing flange, and wherein said cover housing flange is slidably inserted into said latch means and the bottom shell flange. 25. The device of claim 23, wherein said latch means has a lift handle latch with a movable hook, and said engaging means includes a protruding from said cover wall. Fork. 26. The apparatus of claim 16, further comprising means for aligning said bottom shell with said cover shell when said cover shell and said bottom shell are in a closed position, said Devices to be aligned include: at least one alignment hole in said sump wall; At least one alignment pin protrudes from the wall of the cover and can be inserted into the alignment hole. 27. A housing formed from a sheet of thermoplastic material, said housing having a base and sides, said base and said sides forming substantially a containment space, and further comprising a flange formed on said side, said base and said side being vacuum formed, said housing characterized by: A frame comprising an integral extension of at least one side, the frame further comprising: a wall portion suspended by at least one side portion; a flange suspended from said wall portion generally in a direction away from the bottom; and a peripheral edge formed by said flange, said peripheral edge at least partially forming an opening in the housing; characterized in that said frame is molded from sheet material, and in that said The frame extends substantially continuously along at least a portion of the flange. 28. The device of claim 27, wherein the wall portion projects substantially perpendicularly from the side portion. 29. The device of claim 28, wherein the wall portion projects substantially inwardly, towards the contained interior space. 30. The device of claim 27, wherein said flange projects substantially perpendicularly from said wall portion. 31. The device of claim 27, wherein said flange protrudes obliquely from said wall portion. 32. The device of claim 27, wherein the peripheral edge is exposed.

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