US3732651A - Fiberglass shoe for sanding tools - Google Patents

Abstract

A shoe for sanding and rubbing tools is made of laminations of fibre glass of predetermined thickness to provide the right amount of stiffness, flexibility and 100 percent memory. For orbital machines, a vinyl rubbing surface is bonded to the circular shoe with a peripheral edge part forming a tire bonded to the edge of the shoe.

Description

llnited States Patent 1 Rodstein FIBERGLASS SHOE FOR SANDING TOOLS Inventor: Harvey B. Rodstein, 6419 Shenandoah, Los Angeles, Calif.

Filed: Sept. 9, 1970 Appl. No.: 70,849

U.S. C1 ..51/358, 51/170 TL, 51/170 MT Int. Cl. ....B23b 23/04, B24d 11/02, B24d 15/04 Field of Search ..51/358, 364, 170 T, 51/170 TL, 170 MT, 394, 400, 401, 407; 161/93 References Cited UNITED STATES PATENTS 8/1960 Welch ..51/378 11 3,732,651 51 May 15, 1973 3,510,992 5/1970 Hutchins ..51/358 X 2,606,947 8/1952 Happe ....5l/17O MT X 2,334,172 11/1943 Champayne ..51/170 MT 3,082,582 3/1963 Jeske ..51/358 3,533,193 10/1970 Dudek ....5l/170 MT 2,561,449 7/1971 Ruderman ..161/93 Primary Examiner-Donald G. Kelly Attorney- Herzig & Walsh [57] ABSTRACT A shoe for sanding and rubbing tools is made of laminations of fibre glass of predetermined thickness to provide the right amount of stiffness, flexibility and 100 percent memory. For orbital machines, a vinyl rubbing surface is bonded to the circular shoe with a peripheral edge part forming a tire bonded to the edge of the shoe.

2 Claims, 9 Drawing Figures PATENTED 3.732.651

SHEET 2 BF 2 I BY M mu A rrae/vfys I FIBERGLASS SHOE FOR SANDING TOOLS SUMMARY OF THE INVENTION The invention relates to the field of sanding or rubbing tools. Tools of this type are well known, many of them being pneumatically driven. They are provided with a shoe which may be reciprocated back and forth or moved orbitally; the shoe may be rectangular and elongated or circular. In the prior art conventionally the shoe has been made of aluminum for various reasons. The first is that the weight must be minimized otherwise the tool as a whole would be much too heavy and further the vibration of the tool would be excessive. Typically these tools have been subject to a number of serious deficiencies. One of course was that the movement of the shoe occasioned vibration of the tool in use which is a very definite drawback from the standpoint of use by the human operator. More importantly, however, the aluminum does not have complete memory and when bent will not return to its original position or condition thus destroying its usefulness as a shoe because of loss of its planar condition. In use, tools of this type, quite often a portion of the working surface of the tool is applied to the material and considerable pressure may be applied. Thus this part of the surface may be an end part of an elongated reciprocating shoe or an edge surface of a circular or orbital shoe. The pressure will deform an aluminum shoe which will not return to a planar surface thus effectively destroying its usefulness. Furthermore, it is extremely easy forthese aluminum shoes to become bent or deformed in use as a result of rough handling, dropping or the like.

A further drawback to shoes of the type referred to is that the aluminum shoe necessarily at the edge has a rounded bead or fillet rather than a sharp square shoulder. Sanding material which may be paper is attached to the shoe and because of the edge configuration it cannot extend fully to the edge because of the rounded bead or fillet. This creates a serious drawback. Often the edge of the shoe may be used for feathering and because of the fact that the paper does not come all the way to the edge this purpose is defeated and furthermore the edge of the paper tends to fray, tear and wear out so that it has to be replaced after a very short time.

The herein invention is one that effectively overcomes all of the drawbacks described. The concept was originated of a shoe which would have 100 percent memory so that upon being bent or deformed it would return to a true planar condition and further, one that would be a configuration such that sanding paper could extend all the way to the edge of the shoe, and further one that would be sufficiently light as to eliminate or reduce vibration to a minimum. A solution to the problem and realization of the concept came about as a result of a search for and discovery of a construction having the desired characteristics and properties. A shoe having the desired characteristics was realized by a construction comprising two laminations of fiberglass material of different thickness and the laminations being bonded together. Fiberglass is of course a readily available commercial material available in sheets. It was discovered that two laminations bonded together, one lamination being in a thickness of 0.0040 inches to 0.0080 inches and the other in a thickness of 0.0070 inches to 0.00110 inches provided the desired characteristic of stiffness but yet with the ability to bend and percent memory in return to a planar condition after bending. This combination also provided the necessary strength with lightness of weight. Furthermore, this combination provided a shoe which could have a square shoulder at the edge making it possible to secure the sanding paper all the way to the edge and typically by adhesive. It was found that this combination overcame all the deficiencies of the prior art while at the same time bringing forth a number of bonus advantages. The pieces of fiberglass are laminated, that is, bonded together with epoxy, a particular machine having been designed and constructed to perform this operation. The machine is a power press with heating resistors installed in place to provide the necessary heat while laminating under pressure. The sanding paper is typically glued onto the shoe, that is, attached with adhesive. It has been found that a fiberglass shoe of this construction will last a year or more and it is of such construction that it is possible to feather an edge with it.

In the preferred form, a further layer of fiberglass is secured to the shoe by being bonded thereto with overhanging extending side flanges or shoulders to form side guideways to receive guides to provide for the reciprocating movement of the shoe. Thus the entire moving shoe including its attachment means to the tool is made of fiberglass thus contributing to the lightness in weight.

Orbital type tools are at times provided with a disc of rubber or similar composition with a rubbing surface. This material in the past has been bonded to an aluminum shoe but this gives rise to serious deficiencies. When the tool is used in a manner as described in the foregoing the rubber or other composition comes loose ,from the aluminum and readily wears, tears, frays and becomes detached. A construction has been devised to jeliminate these drawbacks. In a preferred form of this construction the rubbing surface is made from a mate- 'ial such as a vinyl which is constructed with an edge Lart in the form of a tire so to speak which is formed pr molded around the edge of the vinyl or fiberglass disc shoe and is bonded thereto.

In the light of the foregoing, the objects of the invention include the following.

The primary object is to reduce the weight of tools of this type, to reduce vibration and to facilitate manual handling.

Another object is to provide a shoe which is flexible and which has 100 percent memory and will retain its planar condition.

Another object is to make available a shoe of the type referred to, to which sanding material can be attached all the way to the edge of the shoe so that the shoe can be used for feathering. A further object is to provide a shoe formed of fiberglass comprised of laminations of fiberglass of particular thicknesses bonded together, whereby to provide the desired characteristics.

Another object is to provide a construction of shoes for orbital types of tools or sanders, wherein the rubbing surface is covered with vinyl having an edge part formed as a tire around the edge of the shoe and is bonded thereto.

Further objects and additional advantages of the invention will become apparent from the following description and annexed drawings wherein:

FIG. 1 is a perspective view of a tool having the shoe of the invention embodied therein;

FIG. 2 is a perspective view of the fiberglass laminations from which the shoe is formed;

FIG. 3 is an illustrative view, illustrating the process of lamination of the fiberglass layers;

FIG. 4 is a sectional view of an end part of a tool of FIG. 1;

FIG. 5 is a section view taken along the line 5-5 of FIG. 4;

FIG. 6 is a sectional view illustrating utilization of the tool;

FIG. 7 is a perspective view of an orbital type tool having the construction of the invention embodied therein;

FIG. 8 is a partial view of the shoe of the tool of FIG. 7; and

FIG. 9 is a sectional view taken along the line 99 of FIG. 8.

The tool shown in FIG. 1 is exemplary of sanding tools of the type shown, for example, in U. S. Pat. No. 3,563,134 issued on Feb. 16, 1971. Typically tools of this type are pneumatically driven, the details of these mechanisms being well-known in the art.

As shown in FIG. 1, the tool comprises a generally elongated body 10, having a tapered front part as shown at 11, and a rear part 12, which has flat inset side portions. The tool has a'handle or grip, as designated at 14. The back part of the grip is secured to the rear part of the tool body and then extending up and over the rear part of the tool, the front part of the grip being secured to the top of the tool body, as designated at 18. A further grip or holding knob, as designated at is attached to and extends upwardly from the forward narrower part of the tool body 11.

The shoe is designated generally by numeral 24. It reciprocates longitudinally with respect to the tool body. As stated, typically the tool may be a pneumatically driven tool, a source of compressed air being connected to the tool through tube or pipe 26, which connects to fitting at the back part of the tool.

Suitably secured to the sides of the tool body by rivets, or the like, are side guide plates 32 and 34, which have inwardly extending foot portions 36 and 38, which form guides for a guide plate 40. The guide plate 40 reciprocates in the guides. The shoe 24 is attached to the guide plate 40, as will be described.

The fiberglass shoe is of rectangular configuration as designated at 44 and is formed of layers or laminations of fiberglass laminated together as described in the foregoing.

Numeral 46 designates a layer, which is a pad of cushioning material which may be sponge rubber, or the like, which is adhesively bonded to the fiberglass shoe. The sanding paper, designated at 50, being secured to the pad 46, by adhesive bonding.

The figures illustrate a preferred form of construction in which the guide plate 40 is also a strip of fiberglass material. Between the shoe 44, and the strip 40, is another narrower strip of fiberglass material, as designated at 52. The strip 52 is adhesively bonded to the shoe 44, and the strip 40, that is the guide member, is adhesively bonded to the strip 52, so that the entire reciprocating assembly other than the pad and the sanding paper is constructed of fiberglass.

The shoe assembly as described, can be secured to the reciprocating drive mechanism by way of pins such as shown at 56, in FIG. 5. FIGS. 2 and 3 illustrate more clearly the construction of the shoe 44. FIG. 2 illustrates two layers or laminations of fiberglass as designated at 60 and 62. These laminations are commercially available in fiberglass, and the preferred thicknesses of the two layers are as follows. Lamination 60 is preferably in a range of thickness of 0.004 inches to 0.008 inches, and lamination 62 preferably has a thickness in the range of 0.0070 inches to 0.00110 inches. The laminations are placed together, overlying each other in a Iiminating machine or tool as illustrated in FIG. 3. Appropriate heat and pressure are applied to bond the two laminations together, the laminations resting on an anvil or a support bed, as designated at 64 and the pressure being applied by a die 66, so that the laminations become a single, integral member, which is the member 44.

The resulting product 44 possesses the desired combination of characteristics, particularly as to strength and lightness of weight. The member 44 has 100 percent memory, meaning that it is bent when pressure is applied to an end or edge, as illustrated in FIG. 6, and after release of pressure, the shoe will return to its exact planar, original condition. The edges of the shoe 44, provide square shoulders so that the pad 46, and/or the sanding paper can be adhesively bonded all the way to the edge of the shoe.

As will be observed in the shoe assembly, it is made of fiberglass, which can flex as shown in FIG. 4, particularly when pressure is applied to an edge, as shown in FIG. 6, and the material having 100 percent memory, will return to its original, planar condition. This is a remarkable advantage compared with metal shoes, particularly considering the weight advantage, the tool being one that is manually handled and the minimization of vibration being critical in importance.

FIGS. 7, 8 and 9 illustrate an adaptation of the invention to an orbital type tool. Tools of this type are also well-known in the art. These tools also typically being pneumatically driven. In FIG. 7, numeral illustrates generally a typical pneumatically driven tool of this type having a generally rectilinear body part 72, and an extending handle part 74. On the upper side of the handle is a controlling lever 76, which controls the supply of driving air through tube connected to a fitting 82 on the handle. At the lower part of the body 72, is cylindrical portion 86 from which extends the shaft 90, which orbits. That is the shaft does not rotate about its own axis, but rather it orbits about a central axis as designated at 92. The stem 90 has an end flange 94, and secured to the stem is the shoe 100. Shoe is made of fiberglass and is of the same construction as the shoe 44. Bonded to the circular shoe 100, is circular fiberglass disc 102. Between the disc 102 and the flange 94 is a metal washer 104. The shoe assembly is secured to the stem 90 by way of a screw 108, having a head 110.

The particular tool illustrated is a rubbing tool. Typically tools of this type in the prior art have been provided with a circular aluminum shoe with a disc of rubber adhesively bonded to the shoe to form the rubbing surface. As previously described, in use the rubber or other composition on such a tool comes loose from the aluminum and readily wears, tears, frays and becomes detached. In the construction of FIGS. 7, 8 and 9, numeral 112 designates a disc formed of vinyl of appropriate thickness which may be a few thousandths of an inch or thicker of perhaps even an eighth of an inch in thickness, which disc is bonded to the shoe 100. Additionally, the disc 112 is provided with peripheral edge parts as designated at 114, having an inwardly extending angular flange 116 adjacent to an angular slot 118, so that the peripheral edge engages over the edge of the shoe 100, as shown, and is securely bonded thereto.

The shoe shown in FIGS. 7, 8 and 9 has all of the desirable characteristics in connection with the previous embodiment. Further, by reason of the rubbing material 112, being formed as described to in effect form a tire around the periphery of the shoe 100, the deficiencies of the prior art constructions are avoided. The vinyl material cannot become unbonded or tear loose from the shoe, and is not similarlY subject to wearing, tearing and fraying and the fact will last practically indefinitely without deterioration.

FIG. 8 illustrates how all edge portions of the shoe can deform or bend and still return to the planar condition with 100 percent memory. This permits operations where pressure is applied to an edge of the sanding disc causing the shoe to bend and to return to normal after the pressure is released. The bonding of the edge of the vinyl material to the sanding disc accomplishes the purposes referred to in the foregoing.

From the foregoing, those skilled in the art will understand the nature and construction of the invention and the manner in which it achieves and realizes all of the purposes and objectives set forth in the foregoing.

The foregoing disclosure is representative of preferred forms of the invention and is to be interpreted in an illustrative rather than a limiting sense, and the invention to be accorded the full scope of the claims appended hereto.

I claim:

1. As an article of manufacture, a shoe adapted for use with sanding or rubbing tools, comprising: a member made of fiberglass material of predetermined thickness, said member being constructed to have sufficient stiffness for rubbing purposes, but having enough flexibility to bend when subjected to pressure and possessing characteristics that after being bent, it will return fully to its original planar condition, a second fiberglass member forming a slider and means securing said second member to the first member in a manner to provide edge portions adapted to be guided for longitudinal reciprocating motion.

2. An article as in claim 1, including a third flat fiberglass member between the first and second members,

and the three members being bonded together.

Claims (2)

1. As an article of manufacture, a shoe adapted for use with sanding or rubbing tools, comprising: a member made of fiberglass material of predetermined thickness, said member being constructed to have sufficient stiffness for rubbing purposes, but having enough flexibility to bend when subjected to pressure and possessing characteristics that after being bent, it will return fully to its original planar condition, a second fiberglass member forming a slider and means securing said second member to the first member in a manner to provide edge portions adapted to be guided for longitudinal reciprocating motion.

2. An article as in claim 1, including a third flat fiberglass member between the first and second members, and the three members being bonded together.

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