MXPA98008124A - Grooved brooch and mét - Google Patents
Grooved brooch and métInfo
- Publication number
- MXPA98008124A MXPA98008124A MXPA/A/1998/008124A MX9808124A MXPA98008124A MX PA98008124 A MXPA98008124 A MX PA98008124A MX 9808124 A MX9808124 A MX 9808124A MX PA98008124 A MXPA98008124 A MX PA98008124A
- Authority
- MX
- Mexico
- Prior art keywords
- slot
- groove
- clasp
- rope
- die
- Prior art date
Links
- 239000000463 material Substances 0.000 claims abstract description 61
- 238000000034 method Methods 0.000 claims abstract description 24
- 238000004519 manufacturing process Methods 0.000 claims abstract description 16
- 238000010438 heat treatment Methods 0.000 claims abstract description 9
- 238000006073 displacement reaction Methods 0.000 claims abstract description 8
- 239000004677 Nylon Substances 0.000 claims abstract description 6
- 230000008901 benefit Effects 0.000 claims abstract description 6
- 229920001778 nylon Polymers 0.000 claims abstract description 6
- 210000004709 eyebrow Anatomy 0.000 claims abstract 2
- 238000005496 tempering Methods 0.000 claims abstract 2
- 239000004033 plastic Substances 0.000 claims description 55
- 229920003023 plastic Polymers 0.000 claims description 55
- 239000002184 metal Substances 0.000 claims description 35
- 229910052751 metal Inorganic materials 0.000 claims description 35
- 238000005520 cutting process Methods 0.000 claims description 25
- -1 polyethylene Polymers 0.000 claims description 12
- 229920001707 polybutylene terephthalate Polymers 0.000 claims description 9
- 239000007769 metal material Substances 0.000 claims description 8
- 230000001419 dependent effect Effects 0.000 claims description 7
- 238000003825 pressing Methods 0.000 claims description 4
- 239000004698 Polyethylene Substances 0.000 claims description 3
- 239000004743 Polypropylene Substances 0.000 claims description 3
- 238000005304 joining Methods 0.000 claims description 3
- 229920000573 polyethylene Polymers 0.000 claims description 3
- 229920000642 polymer Polymers 0.000 claims description 3
- 229920001155 polypropylene Polymers 0.000 claims description 3
- 206010040007 Sense of oppression Diseases 0.000 claims 1
- 150000002739 metals Chemical class 0.000 claims 1
- 239000011324 bead Substances 0.000 abstract 1
- 238000010276 construction Methods 0.000 description 14
- 238000003780 insertion Methods 0.000 description 11
- 230000037431 insertion Effects 0.000 description 11
- 230000007246 mechanism Effects 0.000 description 10
- 230000009471 action Effects 0.000 description 9
- 230000008569 process Effects 0.000 description 9
- 230000000712 assembly Effects 0.000 description 8
- 238000000429 assembly Methods 0.000 description 8
- 230000007423 decrease Effects 0.000 description 6
- 230000003292 diminished effect Effects 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- 238000009825 accumulation Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 229920002292 Nylon 6 Polymers 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009760 electrical discharge machining Methods 0.000 description 1
- 230000009969 flowable effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Abstract
The present invention relates to a clasp and the assembled assembly theris provided, and including a method of forming the clasp and the clasp assembly, the clasp is formed with at least one slot having at least one projection to maintain a cord. resilient press fit in the parallel grooves are provided to receive two cords thereon, having two opposing projections extending towards the groove opening from each side of the groove. The groove projections provide an inherent manufacturing benefit because the punches of the die section that punch pieces of the primordial material feeding the same will not suffer from chipping problems due to the presence of corresponding projections that extend towards the openings of the cavity. of die from each of its sides. Moreover, although the clearances between the projection of the die cavity and the punches are at normal narrow tolerances, the free space between the sides and ends of the cavity and the punches has excessive dimensions so that marks are formed on the sides and ends Corresponding features of the snap groove to grip the bead and provide additional resistance to displacement in the groove, improved settings are also provided for the cords to meet the tolerances required for snapping there, areas of weakness in the cords will be created to assist to your court. Preferred cord materials include those that do not form eyebrows when they are run through spring tempering heat treatment furnaces, such as Nylon and P
Description
GROOVED BROOCH AND METHOD
Field of the Invention The present invention relates to a grooved clasp and method for forming it and, more particularly, to an assembly of attached clasps having an elastic cord inserted into the slots thereof. BACKGROUND OF THE INVENTION In the mattress and bed industry, it has long been known to use pins to join the wires from the shore to the spiral springs. These fasteners have a fairly standard construction generally U-shaped and are formed of a metal preform so that the fasteners have a crown portion and portions of legs that depend on either end of the crown portion. One of the leg portions has a generally bifurcated construction to provide a pair of leg projections that separate from each other, and the other leg portion is formed as a single projection that aligns with the space between the bifurcated leg projections of the leg. so that the projections do not interfere with each other as they are secured around the adjacent wires that have to be joined. For storage, transportation and applications purposes, different ways of collating the clasps have been used in an assembly of joined clasps. Generally, some kind of flexible connecting member is used so that the clips are oriented identically in an end-to-end manner in a row to be loaded into a hand held application tool or a vertical rotation cutting machine (VRC). which cuts individual clips of the assembly and secures them around the wires that have to be held together. Both the manually held application tool and the vertical rotation cutting machine have a piston pulse piston having a blade that cuts the particular connecting member used to hold the clasps together. Various types of connectors have been employed to hold the clasps together in a flexible manner so that the snaps can be wound onto a roll for storage and transport purposes, and so that they can be unwound and fed into the application tool. . Commonly used flexible wire connection elements for interconnecting U-shaped clasps. Parallel wires are attached to the clasps by welding the upper parts of the crowns of the clasps and separated by the aforementioned knife blade on the plunger of the tool. A disadvantage of flexible wire connectors is that they can cause flattening of the plunger blade of the application tool which requires that the plunger blade be sharpened regularly or replaced so that the tool can Consistently separate the clasps from the assembled assembly to secure individual clasps around the wires. It is also known to hold the fasteners together in assembly by plastic cords held in grooves formed in the crown portion of the fasteners, see for example, published application GB 2,023,216 A; U.S. Patent No. 5,303,821; and U.S. Patent No. 5,564,564. Plastic cords have the advantage over their metal wire counterparts that they do not have as much of the flattening effect on the plunger blade of the application tool, and do not require that the blade of the knife be so sharp for the purpose of separating the plastic rope. Because the plastic cords use slots formed in the clasps instead of being welded directly to the snap material, the challenge with the plastic cords is how to better form the slots and properly maintain the cords in them. In this regard, manufacturing and material costs are important considerations, given the additional step required to form the necessary grooves in the fasteners and the generally higher raw material costs for the plastic material against the metal wire. Although it is known to use a friction or pressure adjustment of the plastic cords in the slots of the clasp, this type of connection in and of itself is usually less than desirable to withstand the different tensile forces and the bending and twisting forces to which the rope is to be subjected, such as that caused by the winding and unwinding of the assembly. of the collated brooch, without separation of the rope clasps. Also, due to cost considerations, it is desirable to use the rope of the smallest possible diameter and so that the rope can be separated properly and easily by the application tool, while still maintaining the tolerances required for a consistent friction fit in the brooch snap slot in the collated assembly. Another concern when using very small diameter ropes to adjust by friction in the slots of the clasps is that the slots have to be also of a very small size which can cause problems when they are forming. To form these small slots in a stamping or drilling process, a punch of relatively small size is needed. Small punches that are not very robust can reduce the life of the punch to a level that is not acceptable for large-volume production of glue-cloned snap assemblies. In accordance with the above, the size of the plastic rope and thus that of the slot in which it is adjusted by friction is a compromise between a diameter of the rope that satisfies the desired cost criteria and which allows adequate separation in the Application tool, and an acceptable punch life for the assembly of large volume fasteners. As discussed above, there have been many previous clasps that use special groove constructions to keep the plastic rope in it. It would be desirable to form the grooves of the clasps so that they hold the cord in the grooves without requiring significant modifications to the manufacturing process. In most prior art brooches, their manufacture requires that the additional brooch material be bent or deformed to hold the ropes in the grooves of the brooches, which generally requires an additional manufacturing step, undesirably raising the production costs. In accordance with the foregoing, there is a need for a better formed snap groove to securely receive plastic cords therein. The small diameter plastic cords also tend to have a problem in keeping the cord in a circular cross-sectional shape within the desired tolerances to be properly adjusted by pressure in the slots of the fasteners. With many plastic materials that meet the necessary cost criteria, there is an exchange between achieving the desired cross-sectional shape and having the correct tolerances to press fit the rope in the groove. Another factor in the design of the rope are the casting characteristics of the plastic material that is used. This can be important when the assembled mattress springs that have the __ brackets secured thereon are annealed in a heat treatment furnace. If the heat is sufficient to melt the plastic from the strings in the slots of the brooches, a problem arises if the plastic material gathers in projections so that it creates a bump on the top of the clips. Small bumps like these have to be avoided, since they can create problems when the mattress material is applied on the assembled springs. SUMMARY OF THE INVENTION In accordance with the present invention, a grooved clasp and a collapsed assembly of these fasteners are provided which are connected by at least one plastic cord with the rope or cords securely and captively held in the grooves of the fasteners. Brooches The cords are press fit into the grooves and fastened therein without requiring a separate manufacturing step or deformation of the brooch material to obtain a secure connection of the cord in the grooves similar to many prior collated fastener assemblies. More particularly, projections are provided in the groove so that when the string is inserted and seated in the grooves, the projections resist the rope from slipping off them. In addition, preferably, the groove having the projections is provided with burrs that are intentionally formed in the side walls of the groove to grip the rope to resist movement of the rope in the grooves. Thus, for example, when the blade of a plunger of an application tool is broken, the operation of the same, instead of cutting the cord cleanly, may tend to pull the rope before breaking it causing it to rise in the groove. The projections in the slots of the present clips tend to keep the string properly seated in the slot, and the burrs in the side walls of the slot resist the action of pulling on the string created by the blunt blade of the application tool. . In a preferred form of the invention, a clasp is provided having a body formed of metallic material and having an arched crown portion and dependent leg portions having the clasp a width across the crown and a length transverse to the width . At least one groove extending longitudinally in the body of the clasp and through the portion of the crown thereof is provided to define a slot opening for receiving an elastic cord therein. The lateral surfaces of the groove extend vertically through the body of the clasp and have a predetermined spacing in the transverse direction between them. The previously determined separation is selected to create a friction fit by interference with an elastic cord that is adjusted by pressure in the groove. At least one projection is provided in a predetermined position along the length of one of the side surfaces of the groove and which extends into the opening of the groove to maintain a snap fit of the elastic cord in the groove. the slot against the displacement of the slot. In a preferred form, the side surfaces of the groove include burrs for grasping an elastic cord to resist movement of a rope in the groove in the longitudinal direction. A pair of identical parallel grooves may be provided on the clasp to correspondingly receive a pair of elastic cords fitted by pressure therein. Preferably, a pair of opposed projections is provided which extend into the slot opening from predetermined positions along both lateral surfaces of the slot towards each other. The groove includes opposite ends interconnecting the lateral surfaces of the grooves, and previously determined positions of the projections can generally be midway between the ends of the grooves along the respective side surfaces. To help cut the rope using the application tool, the groove can be formed with V-shaped ends or a thin blade provided therein so that when the rope is seated at the ends of the groove, an area is created of weakness in the rope. In another form of the invention, a joined assembly of attached clasps each having a body of a metal material and including a crown and portions of dependent legs is provided. The clasp assembly includes slots in the bodies of the clasps having slot walls that define slot openings with the bodies of the adjacent snaps having slit openings that are arranged to be in alignment with one another in the snap assembly. A string of elastic plastic material is inserted into the openings of the aligned slots of the adjacent clips to hold the bodies of the adjacent clips together. Burrs are formed on the walls of the slots for grasping the plastic rope to keep the rope substantially fixed in the slot openings of the bodies of adjacent clasps in the snap assembly to hold the clasps together in the collapsed assembly. The grooves may include substantially vertical side surfaces that extend parallel to each other and spaced a predetermined distance through the openings of the grooves one from the other. The plastic rope may have a generally circular cross-sectional configuration with a diameter of a size that provides a frictional fit by interference between the parallel side walls. The rope may be provided with areas of reduced diameter spaced apart therefrom so as to be disposed between adjacent joined clasps or, as mentioned, these can be formed when the rope is inserted into the grooves by the specially formed ends thereof to facilitate the cutting of the rope to separate the clasps from the assembly. The rope may have a contoured surface having a maximum diameter greater than the spacing between the side surfaces of the grooves to provide a pressure fit despite minor variations in diameter along the length of the rope. The contoured surface can be provided as a fluted rope, a fluted rope, a twisted rope, or a helical rope. The helical cord may have a helical projection or helical depression on its outer surface. In this way, the ropes of the invention do not require the adjustment tolerances of a rope having a circular cross-sectional shape to fit by pressure in the grooves while still providing suitable cutting characteristics. Another alternative construction for the rope may be to provide it with a tubular configuration having an outer diameter suitable for the size to be adjusted by pressure in the slot opening between the side surfaces thereof. The tubular rope reduces the amount of plastic material and thus the cost of the rope. In addition, the sheet of the application tool does not have to go through so much plastic material, highlighting its cut-off. Similar to the aforementioned cords, which have an outer contoured surface, the tubular cord may have a larger outside diameter than the cords with circular cross-sectional configurations without significantly impeding the process of insertion of the cord. Preferably, the plastic material of the rope is a polymer that generally flows at temperatures above about 232 ° C (450 ° F). In this way, when the springs of the mattress having the clips applied thereto are annealed in a heat treatment furnace, the string section cut in the groove of an individual broach will melt and flow so that the interfaces between united wires and rolls instead of accumulating. It has been found that a plastic material that satisfies these criteria is polybutylene terephthalate (PBT). Another aspect of the invention is the provision of a die apparatus for forming grooves in a material preform strip. The die apparatus includes upper and lower portions that move towards and away from each other in a cycle to form slots. A perforation is made by the upper portion and includes a groove-forming portion. A die opening is formed in the lower portion and has spaced-apart sides suitable for receiving the groove portion of the punch therein to pierce and separate portions of the material disposed over the die opening when the die portions move a towards the other to form a slot in the strips that have substantially the shape of the die opening. Projections extend to the die opening from one to the other of the sides of the die opening to limit the perforated and spaced portions of the strip material from returning with the punch as the portions of the die move away from each other. According to the foregoing, the projections of the die in the present serve the dual purpose of forming projections in the grooves that help to hold the plastic cord in the same as discussed previously, and enhance the manufacture of the grooves limiting or preventing the drilled metal pieces from being drawn back through the die opening with the punch as it retracts from it. The spaced apart sides of the die opening may extend substantially parallel to each other, and the projections may include a surface spaced apart from the respective sides of the die and extending substantially parallel thereto such that a first space is provided between the portion which forms punch grooves and projection surfaces and a second larger space is provided between the punch groove portion and the sides of the die opening. Preferably, the first space between the groove portion of the punch and the projection surfaces is too large to form burrs on the sides of the corresponding grooves. In another aspect of the invention, there is provided a method for forming an assembly of collated fasteners joined by an elastic cord. The method includes: feeding a section of a metal preform strip over a die opening in a groove-forming die to drill slot openings in the strip; providing projections extending to the die opening from opposite sides thereof; driving a punch against the section of the strip and towards the opening of the punch to perforate an opening of the strip in the section of the strip so that the slot has sides and projections substantially corresponding to the sides and projections of the punch; retract the punch from the die opening; restricting that metal pieces of the strip punched therefrom are attracted from the die opening by projections of the die as the punch retracts; making the section of the grooved strip to a station for cutting the strip and forming brooches by placing a successive section of the strip in position over the openings of the die; cutting and forming a brooch of the section of the grooved strip having the crown broach and portions of legs dependent as the successive section of the strip has a slot opening punched therein, and inserting an elastic cord into the slots of cut grooved brooches and formed to join the clasps together in a collated assembly. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view showing a string insertion station of a process for forming an assembled assembly of grooved clasps joined by plastic cords according to the present invention. Figure 2 is a perspective view of a section of a raw metal strip of material having perforated grooves therein in a groove drilling station of the present process. Figure 3 is a schematic view of the process of forming the assembled assembly of grooved clasps joined by plastic cords according to the present invention. Figure 4 is a perspective view of a generally U-shaped grooved clasp according to the present invention showing a pair of parallel grooves formed in the crown portion of the clasp. Figure 5 is an end elevational view of the clasp of Figure 4 showing "projections extending toward the slot from each side thereof Figure 6 is a side elevational view taken along line 6-6 of FIG. Figure 5. Figure 7 is a view taken along the line
7-7 of Figure 6 and extending through the groove showing the portion of the crown of the brooch in section including the opposing projections extending into the grooves. Figure 8 is a plan view of the clasp showing the crown portion of the clasp and the slots formed therein. Figure 9 is a side sectional view of the clasp taken through one of the slots of the clasp and showing one of the projections thereof. Figure 10 is an enlarged fragmentary perspective view of the clasp of Figure 4 showing one of the grooves and the projections thereof and including in an amplified form the burrs formed in the lower part of the groove. Figure 11 is a plan view of a pressure adjustment of the plastic cord in one of the slots of the clasp. Figure 12 is a sectional view taken along line 12-12 of Figure 11 showing the cord compressed in the groove and the burrs of the groove grasping the material of the plastic cord. Figure 13 is an elevated view of an alternative chord having areas of reduced diameter separated along its length. Figures 14a and 14b are elevational and cross-sectional views, respectively, of a rope having a helical depredation formed around its outer surface along the length of the rope. Figures 15a and 15b are elevational and cross-sectional views, respectively, of a rope having a helical projection extending around its outer surface along the length of the rope. Figure 16 is an elevated view of a twisted rope. Figure 17 is a representation of the shape of an external contour surface of a rope having a grooved configuration. Figure 18 is a representation of the shape of an outer contour surface of a rope having a fluted configuration. Figure 19 is a plan view of a cutting section of the preform strip with slots formed therein having V-shaped ends to create an area of weakness in the string when it is snapped into it. Figure 20 is an enlarged view of one of the V-shaped ends of the slot. Figure 21 is a sectional view taken along line 21-21 of Figure 20. Figure 22 is a plan view of a section of the preform strip having grooves formed therein with the ends of the slot including a thin edge to create an area of weakness in a snap fit of the string in the slot. Figure 23 is an enlarged view of one end of the groove showing the thinned edge thereof. Figure 24 is a sectional view taken along the line 24-24 of Figure 23. Figures 25 and 26 are views of alternative constructions for the plastic rope showing the cross sectional configuration thereof with a upper portion and a lower foot portion to be adjusted by pressure in the slots of the clasp. Figure 27 is a perspective view of a die press including the upper and lower portions thereof and showing punches to be urged into the die openings to form the slots in the metal preform strip. Figure 28 is a plan view of a die insert including die openings with projections extending toward the opening on each side thereof. Figure 29 is a sectional view taken along line 29-29 of Figure 28 through one of the die openings and showing the opening step toward a larger opening in the insert and which has a decrease to it. Figure 30 is an enlarged view of the shape of one of the die openings.
Figures 31-34 are several views of a punch carried by the upper portion of the die press. The Figure 35 is a perspective view of an extension arm to be operatively connected to the upper portion of the die press and having an air spring to control the operation of the cord insertion station. Figure 36 is a plan view of the extension arm of Figure 35 showing an opening in the arm for mounting the air spring therein. Figure 37 is an elevational view of the extension arm and showing a fastening portion for mounting the upper part of the die and a reinforcing portion for providing strength to the arm. Figures 38-41 are several views of a string insertion block including parallel diminished edges that push the string into the slots and progressively settle them. Figure 42 is a perspective view of the clasps herein anchored around an edge wire and spiral springs of a mattress; and Figure 43 is a sectional view of a hand-held clasp application tool showing a collapsed row of clasps loaded thereon with the front clasp in position to be cut out of the assembly by a plunger blade. the application tool. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGURES 1-3 show a process or method for forming an assembled assembly 10 of individual grooved clasps 12 which are joined by at least one elastic cord 14 of plastic material that is inserted at least a corresponding slot 16 formed in the clasps 12 accommodated in an end-to-end orientation with their respective grooves 16 aligned. In the preferred form, two parallel slots 16 are formed in each clasp 12 to receive a pair of strings 14, as shown. Referring to Figures 4-6, the clips 12 are of identical construction because each has a body 18 of metallic material having a generally U-shaped construction that includes an arcuate crown portion 20 with leg portions 22 and 24 depending on each end of it. As is known, one of the leg portions 22 can be provided with a bifurcated construction with a pair of leg projections 26 and 28 that are separated from each other on either side of the clasp 12 so as to provide a space intermediate 30 between them. At the other end of the crown portion of the clasp 20, the dependent leg portion 24 thereof includes a single intermediate leg projection 32 which is aligned with the intermediate space 30 between the leg projections 26 and 28 in the other. end of the brooch crown portion 20. Thus, when the brooch 12 is secured by the application tool 34 around the wires 36 and 38 to be connected (Figure 43), the leg projections 26 and 28 and the projection of leg 32 will move toward each other with respect to wires 36 and 38, the intermediate projections having space to move past projections 26 and 28 through space 30 formed therebetween. As shown in Figure 3, the present grooved pins 12 and, in particular, the assembled assembly 10 thereof, can be formed in a three-step process relatively directly by providing a slotting station 40 before and a station. rope insert 42 after a conventional material cutting and pin forming station 44 that cuts a preform strip 46 of grooved metal material as it leaves the slotting station 40 and shapes it into the shape previously described. of the body of the clasp 18. Unlike the assembled slotted snap assemblies, there is no separate or additional step that is required to obtain a secure connection of the string 14 in the slots 16 of the present snaps 12, as will be more fully described. at the moment. To keep the plastic cords in the slot 16 of the clasps 12, an interference friction fit is provided by press fitting the cords 14 in the slots 16 in the string inserting station 42. More particularly, the size of the slot 16 is coordinated with the size of the strings 14 so that when the string 14 is inserted into the slot 16, it will be compressed against the opposite sides or the side walls 48 and 50 of the slots 16, as best seen in FIG. Figure 12. Since the rope 14 is made of elastic plastic material, it will deform in the groove 16 having an engagement by friction between the outer surface of the rope 52 and the surfaces 48a and 50a of the sides of the groove 48 and 50. When the string 14 is snapped into the aligned slots 16 and frictionally maintained therein due to interference fit, a flexible collapsed assembly 10 of the attached snaps 12 is provided which is similar in flexibilida d to that of the clasps joined by metal wires for ease in rolling and unrolling them. As it is apparent and as commented above, when the assembled assembly 10 of the clasps 12 is subjected to various tensile forces and bending and twisting forces as may occur during winding and unwinding, a problem arises if these forces are sufficient to overcome the frictional resistance between the surface the rope 52 and the surfaces of the slots 48a and 50a so that the strings 14 slip out of the slots 16, separating the clasps 12 from the collated assembly 10. This can also be a problem when the knife blade 54 of the plunger of the Application tool 56 is blunt and begins to exert a pulling action on the strings 14 to separate them from the rest of the strings 14, instead of applying the clean cutting action the strings 14 between adjacent clasps 12 in the assembly 10 will count. this occurs, the operation of the plunger 56 of the tool 34 can pull the cord 14 through the slots 16, overcoming the frictional resistance between the surfaces is of the slots 48a and 50a and the surface of the rope 52, and may also cause the rope 14 to rise in the slots 16 to move up and out of the same as the plunger 56 pushes down on the string 14 before of breaking it without a clean cutting action between the cord section 14a in the front clasp 12a of the clasp assembly 10 loaded in the tool 34 and the remainder of the cord 14. In accordance with the present invention, at least one projection, and preferably a pair of projections 58 and 60 are formed in the slotting station 40 and extend from the respective sides 48 and 50 towards the slot opening 62 defined therebetween, as can be seen in Figures 5 and 7. -12. Projections 58 and 60 are described in the co-pending co-pending patent application of applicants with Serial No. 08 / 942,533, which is incorporated as if reproduced in its entirety herein. More particularly, the side surfaces 48a and 50a are formed so as to extend substantially vertically all the way through the body of the clasp 18 so that when the slots 16 are perforated, they extend from the top surface 64 through the surface lower 66 of the metal preform strip 46.
The strip 46 is formed in its U-shaped configuration at station 44 so that the upper surface of strip 64 is oriented as the outer surface of the body of the clasp and the lower surface of strip 66 is oriented as the inner surface of the body of the brooch. Thus, the walls of the slot 48 and 50 extend through the body of the clasp 18 from the outer surface 64 to the inner surface 66 thereof so that the opening of the slot 62 is an opening through the body of the clasp. 18. In this regard, the surfaces of the walls 48a and 50a are formed in the slotting station 40 so as to be orthogonal to the surfaces of the clips 64 and 66, and extend substantially vertically from the outer surfaces of the clips. clasp 64 to the inner surface of the clasp 66. The projections 58 and 60 preferably have a substantially paired configuration and are disposed opposite one another through the opening of the slot 62. In other words, the projections 58 and 60 extend each toward the other in the slit opening 62 to form a restrictive throat section 68 therebetween, as best seen in Figures 7 and 8. Referring to Figure 1 2, when the rope 14 is fully seated in the groove 16 compressed between the walls 48 and 50 thereof, the peripheral compressed portions of the rope 14 will be disposed below the bottom portions 59 and 61 of the projections 58 and 60 in a manner that the projections 58 and 60 resist the displacement of the string 14 in the slot 16 and, in particular, in a direction upwards and around the bottom parts 59 and 61 and passing the projections 58 and 60 and out of the slot 16 away of the body of the brooch 18. As described herein, the body of the brooch
18 will be considered to have a width extending between sides 70 and 72 thereof and a length that is transverse to the width at which in the preform cut from a particular brooch, see for example, Figures 19 and 22, the length is considered to run from the distal ends 74 of the leg projections 26 and 28 to the distal end 76 of the leg projection 32. In accordance with the above, it will be understood that when referring to the transverse direction generally will be in one direction through the body of the clasp 18 and particularly the crown portion 20 thereof, and the longitudinal direction will be in the direction parallel to the sides 70 and 72 of the body of the clasp 18, such as along the portion of crown 20 thereof. As previously described, the projections 58 and 60 extend toward the opening of the slot 62 and define the throat 68 therebetween. "The throat 68 is bounded by substantially flat and vertical surfaces 58a and 60a of the respective projections 58 and 60 that they are parallel to the corresponding vertical wall surfaces 48a and 50a.The distance through the wall surfaces 48a and 50a in the transverse direction, wl r is in accordance with the above greater than the distance across the surfaces of the walls. projection 58a and 60a in the transverse direction, w2 as shown in Figure 12. Furthermore it can be seen from a comparison between Figures 11 and 12 that the outside diameter, d, of the outer surface of the rope 52 is made the size which is greater than both x and w2 so that the rope 14 undergoes two different stages of compression as it is inserted into the groove 16. With respect to this the plastic material for the rope 14 t It must be sufficiently deformable so that its diameter d can be compressed to one equal to w2 to fit through the throat 68 between the projection surfaces 58a and 60a. In addition, the string material should be selected so that it is easily cut by the plunger blade of the plunger 54 of the application tool 34. Generally, the smaller diameter of the rope 14, the better the characteristics of cutting or separation of the same. However, the rope 14 must have the elasticity together with a non-deformed diameter of sufficient size, d, which provides a tight friction fit, well, in the groove 16. While a smaller width vx the opening of the the groove 62 can be formed so as to exert greater compression on a rope of a given diameter for proper frictional engagement therewith, it should be kept in mind that the punches 78 used to form the grooves 16 can not be so small as to negatively impact about its resistance and durability. Thus, the cords 14 and the grooves 16 have their sizes coordinated to give the cords 14 suitable cutting ability characteristics while maintaining a good friction fit in the grooves 16 and provide an acceptable life for the punches 78 By way of example, the distance through the opening of the groove 62 between the surfaces of the vertical side walls 48a and 50a, wlf is preferably approximately 0.127 centimeters (0.050 inches), and the distance across the surfaces of protection 58a and 60a, 2, is preferably approximately 0.107 centimeters (0.042 inches-). Thus, the thinned throat section 68 of the slot opening 62 is reduced by approximately 0.203 centimeters (0.008 inches) over the remainder of the slot opening 62 defined between the walls 48 and 50. Given these dimensions for the slots 16, the Plastic rope 14 such as polyethylene or polypropylene material has a diameter of which is preferably in the range of about 0.1168 to 0.1371 centimeters (0.046 to 0.054 inches). It has been found that forming the rope 14 from polyethylene or polypropylene material within the above diameter range provides the rope 14 with an acceptable cost and has good cutting characteristics, and the rope 14 can be adjusted by pressure through the section of throat 68 to be compressed in slot 16 between the side walls, 48 and 50 thereof. A nylon 6 polyester plastic material having minimal stretch or no stretch during the manufacture thereof could also be used. Minimizing the stretching of the nylon reduces its strength sufficiently so that it can be cut properly by the application tool 34. It has been found that with these plastic materials that in very small diameters in the present, it is difficult to keep them circular in cross section inside. of tolerances of ± 0.0127 centimeters (± 0.005 inches) along its length as with particularly low density materials, tend to oval under cooling after extrusion in the stretching process. Another significant feature of the present invention is the formation of burrs 80 in the side walls of the slot 48 and 50 during the slotting step in the station 40. The following is a description of the relationship between the dimensions of the punch 78 and the slots 16; for the purposes of the following description the dimensions should be understood as substantially corresponding to the dimensions of the die openings 160 and 162 which will be described more fully hereinafter. The burrs 80 are formed as the punches 78 are urged through the preform metal strip 46 due to the larger space provided between the groove portion 82 of each of the punches 78 and the side walls 48 and 50 against the punches. tight spaces between the portion forming the slot 82 and the projections 58 and 60.
Normally, burrs such as those formed in the walls of the slots 48 and 50 in the manufacture of metal parts such as the snaps 12 in the present would be avoided. However, applicants have found that the burrs 80 are advantageously provided in the grooves of the fasteners 16 to enhance the holding power to keep the cords 14 fixed in the grooves 16. More specifically, the portion forming perforated grooves 82 has its respective internal and external sides 84 and 86 that have a gap only slightly smaller than the spacing w2 through the projection surfaces 58a and 60a, such as in the order of 0.0076 centimeters (0.003 inches), which is within the suitable stamping tolerances to avoid burr formation on these surfaces 58a and 60a. On the other hand, the space between the sides 84 and 86 of the perforated slot-forming portion 82 is approximately twice that of the space described above, ie 0.0152 centimeters (0.006 inches), which is normally beyond the tolerance of desired embossment to form the slots or slot openings 62. Thus, when the punches 78 are propelled through the metal material 46, elevated burrs 80 are formed in the slot 16 in the bottom side 64 of the preform metal strip 46. When the strip 46 is cut and forms the U-shaped snap body 18 in the station 44, the raised burrs 80 of the bottom of the surfaces of the walls 48a and 50a are oriented so that they generally extend from a way that is longitudinally opposed to the displacement of the rope 14
< - ~. ) / in the groove 16. In other words, the burrs 80 are formed due to the too large gap between the sides 84 and 86 of the portion of the punch forming grooves, and the surfaces of the corresponding side walls 48a and 50a are such that as the punch 78 is driven through the metal strip 46, there is no clean cutting action and instead the pieces of metal 88 are
separate from the bottom of the surfaces 48a and 50a in a manner that is more like the tear action. This causes burrs 80 to be formed therein which will generally project downwardly from the underside 64 of the strip 46 and in a direction toward the opposite surface 48a or 50a from one in the
which are formed. As the preform 46 having slot openings 16 punctured therein is cut into a section, the strip section is also folded around a mandrel (not shown) in its U-shaped shape with the slotted walls 48 and 50 which now they have an upward or convex orientation
The curve coincides with that of the crown portion of the body of the clasp 18. According to the above, there will be burrs 80 which, instead of extending downwards from the walls of the slots 48 and 50, now tend to project at an angle relative to the vertical and inward toward the opposite wall 48 or 50.
Thus, when the string 14 snaps into the slot 16, the burrs 80 will grip the string 14, and when a pulling force is exerted such as along the length of the string 14, the burrs 80 will tend to dig and bite on the rope 14 to resist the longitudinal displacement of it. Applicants have found a significant advantage in intentionally providing burrs 80 on the walls of the slots 48 and 50 during forming thereof so as to improve the clamping power of the slots of the clasps 16 on the strings 14 over that provided by the friction fit described above and the projections 58 and 60. Accordingly, when the formed fastener bodies 18 come from the station 44 to the cord insert station 42, the cords 14 are snapped into the grooves 16 by first compressing the strings 14 the projections 58 and 60 from their undeformed diameter, d, down to a width equal to aw, through them. The continuous insertion force eventually causes the string 14 to substantially pass the projections 58 and 60 so that its diameter through the opening of the slot 62 now expands to equal x which is still less than its non-deformed diameter. , but greater than 2. With the string 14 fully inserted into the slot 16, it will settle at the curved or arched ends 90 and 92 interconnecting the slot walls 48 and 50 at either end thereof. The seated rope 14 will be grasped by the burrs 80 in the walls of grooves 48 and 50 between which the rope 14 is compressed, and also at the ends of the groove 90 and 92. The projections 58 and 60 are formed approximately halfway between the ends of the groove 90 and 92 in their respective side walls 48 and 50. With the rope 14 seated at the ends 90 and 92 and compressed between the side walls 48 and 50, the rope 14 extends generally linearly between the ends of the rope. the slots 90 and 92 so that a portion thereof extends below the underside 66 of the crown portion 20, as can be seen in Figure 43. As discussed above, with the small diameter plastic cords 14, it can be difficult to maintain an outside diameter that at all points along the length of the rope is greater than the distance Wj through the side walls of the slot 48 and 50. In addition, provide the cue 14 is too large in diameter so that even when it is in its minimum tolerance the diameter of it is still larger than the distance w2 through the walls of the slot 48, 50 can create problems in both the process of inserting the rope as when the rope is to be cut by the application tool 34. In accordance with the foregoing, several alternative constructions of plastic cords are shown which are designed to meet the aforementioned needs in Figures 13-18. In Figure 13, a rope 94 is shown which is provided with areas "96 of reduced cross-sectional diameter formed during the extrusion of the rope 94. The areas of reduced diameter 96 can be separated along the length of the rope. rope 94 at predetermined locations such that these areas 96 fall between adjacent clasps 12 in the collated assembly 10. In this manner, the blade of the application tool 54 will be able to cut through the cord 94 along the areas of small diameter 96 thereof to provide for the easier separation of the rope 94 therein As an alternative, instead of extruding the rope 94 with these areas 96, the plastic rope can be mechanically notched or notched. before insertion into the groove of the clasp 16. The Figures 14a and 14b show a rope 98 having a surface with external contour 100 having a maximum diameter that is greater than the distance wx through the slot walls 48 and 50. The contoured surface 100 has a helical depression or recess 102 formed therein and along the length of the rope 98 so that in diametrically opposed positions at all places along the length of the rope there will be opposed notches 102a of the recess 102 disposed therein, as best seen in Figure 14b. The provision of the hollow surface 100 allows the diameter of the rope 98 to be increased slightly to provide looser tolerances to satisfy the cord insertion and shear characteristics required for the collated assembly of slotted clasps 10 herein. The larger diameter rope 98 also provides an increase in the frictional forces exerted between the slotted walls 48 and 50 and the surface of the rope 100. Figures 15a and 15b show a variation on the rope 94 in that instead of providing a helical recess 102, the cord 104 has an outer surface with contour 106 by means of the elevated helical projection 108 which extends along the length of the cord 104. As can be seen in Figure 15b, the projection 108 provides the rope with 104 diametrically opposed raised projection portions 108a at all places along the length of the rope. The maximum diameter of the cord 104 is presented as measured by the projection portions 108a which may be greater than the maximum outer diameter of the cord 14 having a circular cross-section since there is not much cord material of the cord. plastic in this diameter. In this way, the projection portions 108a can be compressed past the slot projections 58 and 60 and loaded against the walls of the slots 48 and 50 with increased frictional resistance due to their larger diameter. In addition, the tolerances for the cord 104 are not as critical due to the larger outside diameter in the projection 108 thereof. Figure 16 'shows a twisted rope 109 having a helical twist to form reduced helical cross-sectional areas 109a along its outer surface providing many of the same or similar benefits as the strings 98 and 104. A metal can also be provided. tubular construction for the rope 14 to obtain similar benefits provided by the ropes of Figures 13-16 in terms of having a larger diameter while still retaining the ability to be easily cut by the application tool 34. Figures 17 and 18 show alternative contoured surfaces 110 and 112, respectively, which can be used for the rope to provide it with a maximum diameter larger than possible with the cord with regular circular cross-section 14. These two contoured surfaces 110 and 112 have projections longitudinals 110a and 112a, respectively, which can be adjusted by pressure through of the slot projections 58 and 60 to bear against the slot side walls 48 and 50 to maintain a strong friction fit therebetween while allowing looser tolerances to form the respective strings due to the larger maximum diameter. Figure 17 shows a fluted rope with the projections being elongated channels 110a, while Figure 18 shows a fluted rope with raised fluted projections 112a formed between "concave longitudinal depressions 114. Another way to improve the cutting characteristics of the strings 14 is to provide special shapes to the ends of the rope for notching or notching the rope 14 as an incident of inserting the rope 14 into the groove 16 and seating it at the ends thereof With reference to Figure 19-24, two different constructions of the ends of the slots 116 and 118 are illustrated, respectively, Figures 19-21 modify the normally rounded ends 90 and 92 and give them a V-shape. Accordingly, each of the ends of the slots 116 are provided with converging walls 120 and 122. As shown, the wall 120 extends from either end of the wall of the wall. slot 148, and wall 122 extends from either end of the wall of slot 150 with walls 120 and 122 at respective slot ends 116 meeting to form a sharp corner 124 at their junction. Thus, when the string 14 is pressed into the slot 16 in the string insertion station 42, the string 14 will be tightly seated at the V-shaped ends 116 with the acute corner 124 effective to enmesh the string 14 in the same. This notch formation of the rope 14 creates an area of weakness therein which allows it to be more easily cut and separated by the plunger blade 54 of the application tool 34. Instead of modifying the curved ends 90 and 92 for to provide the V-shape thereto, Figures 22-24 show slot ends 118 which are provided with a thin edge 126 such as by forging or wedging thereof. In other words, the material of the body of the clasp 18 adjacent the ends 118 has pressure applied thereto along the outer and inner surfaces 64 and 66 thereof so that the decreased surface portions 62a and 64a are formed by extending to the openings of the same. the grooves 62. The diminished surface portions 62a and 64a lie on a thin edge 126. Accordingly, wedging the ends of the grooves 118 provides an area of thinned material 128 that includes the thin edge 126 of the groove. same at the slot ends 118 so that when the string 14 snaps and sits on the ends 118, the thin edge 126 will cut a notch in the string 14 to provide an area of weakness therein aiding the cutting of the string. the rope 14 by the application tool 34. Figures 25 and 26 are directed to alternative ropes 130 and 132 respectively, each one including a configuration in section t different transverse. As shown, each of the ropes 130 and 132 includes the respective upper and lower portions. The upper portion 134 of the rope 130 has a lower foot portion 136 which depends thereon, and the upper portion 138 of the rope 132 has a lower foot portion 140 which depends thereon. The only difference between the ropes 130 and 132 lies in the configuration of their respective foot portions 136 and 140. While the sides 136a and 136b of the foot portion 136 are substantially straight and vertical except for the round curved bottom portion 136c of the same, the foot portion 140 has a substantially circular configuration except at its junction with the upper portion 138 thereof. The configuration of the upper respective portions 134 and 138 are substantially identical and will be in the upper portion of the crown portions of the clasp 20 with the respective foot portions 136 and 140 pressurized in the slots 16. The rope 132 through its foot projection 140 provides greater frictional engagement with the walls 48 and 50 of the grooves 16 due to the greater diameter of the foot portion 140 thereof against the spacing between the sides 136a and 136b of the lower foot portion of the foot. the rope 130. The reason for this is due to the circular configuration of the foot portion 140 provided by the free areas 142a and 142b in which the projections of grooves 158 and 60 can be extended, as opposed to the wall surfaces right 136a and 136b of the foot projection 136, where the projections 58 and 60 will puncture in the projection 136. On the other hand, the reduced friction engagement between the surfaces foot portion ices 136a and 136b and the walls of slots 48 and 50 due to the narrower nature of the portion of the foot 136 on the circular foot portion 140 is compensated for by the aforementioned puncturing action exerted by the projections 58 and 60 on the portion of the foot 136 for keeping it secured in the groove of the clasp 16. Referring now to Figure 27, there is shown a die press apparatus generally designated with reference numeral 144 that can be used in the station. slotting 40. The die press apparatus 144 generally includes a portion of upper perforation plate 146 carrying the pair of punches 78, and a lower guide plate and die block portion 148. More particularly, portion 148 includes the upper guide plate 150 having a pair of parallel oval guide slots 152 and 154 extending therethrough in alignment with the punches 78, and a block of lower die 156 in which the die insert 158 is secured by having a pair of parallel die cavity openings 160 and 162 formed therein. The cycling of the upper and lower die portions 146 and 148 towards and away from each other pierces the grooves 16 in the preform strip 62 of the metal material fed over the openings of the die 160 and 162. Preferably, is the upper perforated plate portion 146 which moves toward and away from the fixed lower portion 148 during a groove forming cycle. The piercing plate portion 146 runs up and down along guide pins 164 which extend through the corresponding openings 166 formed in the plate 146. The guide pins 164 are rigidly fixed at each corner of the lower plate and the block portion 148 with the traversed apertures 166 correspondingly formed in each corner of the upper plate portion 146. The plate portion 146 is biased to its open position with the punches 78 and more particularly the groove portion 82 thereof retracted outside the guide slots 152 and 154 and the corresponding die cavities 160 and 162 by means of spiral springs 168. The guide plate 150 has an elongated recess 170 formed in its lower side_172 extending longitudinally in a direction towards and passing the guide slots parallel 152 and 154 and having a width sufficient to receive the width of the preform metal strip 62. Thus, with the With guide 150 assembled to die block 156, lower side 172 of guide plate 150 will be embed with top surface 174 of die block with recess 170 cooperating with surface 174 to provide a passage through for the strip preform 62. which is to be fed in position over the die openings 160 and 162 to have the slots 16 punctured therein by the punches 78 as the puncher plate 146 is pushed down against the inclination of the springs 168. After that the section of the metal strip 62 has a pair of slots 16 punctured therein, is fed outwardly from the downstream end of the recess 170 to the preform cutting and snap forming station 44 for further processing by placing the section successive of the preform strip 62 in position over "the die openings 160 and 162. A problem that occurs when very small pieces of metal are drilled 88 rather lightweight metal foil preform material such as the preform strip 62 is that the lubricating fluids tend to create sufficient surface tension so that the pieces of metal 88 can be attracted with the punches 78 as they retract out of the apertures of die 160 and 162 which can cause problems with the subsequent cycle of the die press 144 to form slots 16 in successive sections of the strip 62. To handle this problem of the return of the metal pieces, the openings of the die 160 and 162 they have projections 176 and 178 that extend into die openings 160 and 162 from respective sides 180 and 182 thereof. To complete the generally oval shape of the die cavity openings 160 and 162 minus the projections 176 and 178 extending therein, the substantially parallel, straight die cavity sides 180 and 182 are interconnected by arcuate ends or rounded 184 and 186 at either end of the die openings 160 and 162. As previously explained, the dimensions of the openings in the die cavity 160 and 162 are substantially the same as the previously described dimensions for the brooch slots. 16. Referring to Figures 31-34, the construction of the punches 78 is illustrated and shows an enlarged head 188 having a generally circular configuration with a plane 188a on one side thereof for joining in an opening (not shown) on the underside of the perforation plate 146. Beneath the head 188, an enlarged body portion 190 of the punch 78 is provided having superf decreased arched and converging icies 190a and 190b in the lower part and on either side thereof. The converging surfaces 190a and 190b are interconnected at their distal ends by the flat bottom surface 190c to which the piercing groove portion 82 is attached. The groove-forming portion 82 has a generally oval cross-sectional configuration for adjustment in the openings of the die cavities 160 and 162 and between the projections 176 and 178 extending therein, as best seen in Figure 34. Accordingly, the sides 84 and 86 of the portion forming the slot 82 are interconnected with rounded ends 192 and 194. The construction and size of the previously described punches 78 are has found that it provides the punches 78 with sufficient sturdiness for the high volume production of the snap assemblies 10 herein. When the upper portion of the die apparatus 146 is urged toward the lower portion 148, the groove portion of the punch 82 pierces the metal pieces 88 of the section of the preform metal strip 62 placed over the die cavities 160 and 162 to form slots 16 therein that have a substantially mated configuration with these cavities. As the slot-forming portion 82 of each of the punches 78 enters the die cavities 160 and 162, the space provided between the sides of the punch slot 84 and 86 and the projections of the die cavity 176 and 178 is substantially the same as that described above with respect to the slots of the clasps 16, that is to say in the order of approximately 0.0076 centimeters (0.003 inch-days), while the space between the sides 84 and 86 and the sides of die cavity 180 and 182 are too large, on the order of 0.152 centimeters (0.006 inches). In this way, the perforation of the grooves 16 in the preform strip 62 will create burrs in the side walls of the groove 48 and 50 due to the too large space between the sides of the perforated groove portions 84 and 86 and the sides of the groove. the die cavity 180 and 182. The very fair dimensions between the piercing portion 82 and the projections 176 and 178 make it very difficult for the metal pieces 88 to come loose from the cavities 160 and 162 with the punches 78. Any attraction of the pieces of metal 88 requires that they be properly aligned between the projections of the cavity 176 and 178, which is very unlikely due to the larger spaces, and thus there is room for the metal pieces to move between the piercing portion 82. and the sides of the cavity 180 and 182. As it is apparent, the formation of the projections 58 and 60 in the grooves of the clasps 16 facilitates the improved fastening of the rope 14 therein as well as provides beneficial Manufacturing processes by limiting the attraction of the metal pieces 88 back to the cavities 160 and 162.
Referring to Figure 29, die insert 158 may include an upper portion of carbide plate 196 attached to a lower portion of metal mounting block 198. Cavities 160 and 162 may be machined as by electrical discharge machining ( EDM) in an identical manner to each other showing Figure 29 the construction of die cavity 160. As shown, die cavity 160 preferably has an upper portion 200 that is stepped opening to a larger lower portion 202 in the assembly block 198 and opens in the lower part thereof to provide an empty hole for the perforated metal pieces 88 of the preform strip 62 with the shoulder 204 formed between the upper and lower portions 200 and 202. Also, as discussed previously, the projections 176 and 178 will also limit any attraction of the metal pieces through the upper portion of the cavity 200. To further assist the cr In the case of a path of least resistance outside the lower part of the die insert 158, a slight inclination or decrease such as of the order of half a degree can be machined by electric discharge in the cavities 160 and 162 of about the midpoint of the upper portion. from the cavity 200 and through the lower portion of the cavity 202 to the lower part of the assembly block 198. After the slotting station 40, the sections of the perforated preform strip 64 are successively fed to the station. of preform cutting and forming of clasps 44 where the bodies of slotted U-shaped clasps 18 are formed which are then fed to the string insertion station 42. A shape of one of these stations is shown in Figure 1 where a pair of strings 14 are shown on the reels 206. The strings 14 are unwound from the reels 206 and are directed over a nose guide 208 having guiding grooves. parallel arcuate as 210 formed therein which redirects the strings 14 again under a pressure mechanism 212 and string under which the bodies of individual pins 18 run with their respective slots 16 in linear alignment with each other. The rope pressure mechanism 212 includes a lower wedge block 214, as best seen in Figures 38-41. The wedge block has an upper inclined surface 216 that decreases downwardly from upstream to downstream in the direction of travel of the clasp 218 and a substantially flat horizontal bottom surface 220 in which a pair of elongated cord insertion ridges is formed. 222. The ridges 222 similar to the upper surface of the block 216 are slightly diminished downwards from upstream to downstream, such as with a decrease of 2o with respect to the horizontal. The grooves 222 are laterally spaced a distance equal to that of the parallel grooves 16 formed in the bodies of the fasteners 18 so as to be aligned thereon. The cords 14 fed over the slots of the bodies of the clips 16 are pushed and inserted into the slots 16 by the diminished wedges 222 as they make the path under the block 214. More specifically, the pressure mechanism of the cord 212 makes reciprocal movement in a vertical manner up and down in synchronization with the upper plate of the die press apparatus 146 so that a pair of slots 16 are drilled from a section of metal strip 62 which is to be formed as a die body. individual snap 18 at station 44, pressure mechanism 212 will go through a corresponding stroke up and down. As the wedge block 214, and specifically the diminished grooves 222 thereof, are longer than the length of the bodies formed of U-shaped clasps 18 as by approximately three to seven times, each snap body 18 will be subjected to a corresponding number of strikes of the string pressing mechanism 212. And due to the progressively increasing downstream decrease of the wedges 222, the strings 14 will be pushed progressively downwards and will settle more in the grooves 16 as they move downstream under the wedge block 214. As the strings 14 progressively settle in the grooves 16, the opportunity for the breaking of the strings is reduced. the rope during the insertion stage of the rope. To mount the lower wedge 214 in a suitable position in relation to the bodies of the snaps 18 running under it, an upper adjusting wedge block 224 is provided having a sloping lower lower surface 224a which has a decrease substantially matched to that of the upper surface 216 of the wedge block 214. The upper surface of the adjustment block 224 is fixed to the impact plate 226, and the wedge block 214 is slidable relative to the block 224 so that its position in the direction of travel of the clasp 218 can be adjusted or fine-tuned to provide the desired chord pressure action for proper seating of the chords 14 in the slots of the clasps 16. To cause the vertical reciprocating action up and down of the mechanism that presses the rope 212, an extension arm assembly 228 is provided, as shown in Figures 35-37. The extension arm assembly 228 includes a fastener portion 230 at one end that is operatively connected to the piercing plate 146 of the die apparatus 144 so that the extension arm assembly 228 moves up and down therewith. At the other end of arm 228, an air cylinder mounting portion 232 is provided which includes an internally threaded opening 234. An air cylinder 236 having an outer cylinder housing 238 with a lower portion with external thread 240 is it screws into opening 234 and is securely huddled in place therein as by bolts. A piston piston 242 is externally inclined from the cylinder housing 238 from the bottom thereof to engage the impact plate 226 of the rope pressing mechanism 212 as the extension arm assembly 228 is traversed vertically downward when the punch plate of the die apparatus 146 is urged downwardly to form the slots 16 in the strip 62. In order to give strength to the extension arm assembly 228, a reinforcing portion 244 extending from the fastener portion can be formed. 230 to the air cylinder mounting portion 232. In this manner, the extension arm assembly 228 is provided with sufficient force to withstand repeated impacts against the impact plate 226 for the production of high volume grooved fastener assemblies. 10. After the strings 14 are fully inserted into the grooves 16 as they move downstream past the pressure mechanism of rope 212, collated clips 12 can be formed into rolled assemblies for storage and transport or cut into assemblies with a predetermined number of clasps 12 by a cutting mechanism 244, such as that shown in Figure 1. The cutting mechanism 244 may include a roller wheel 246 having a cutting blade 246 loaded with spring 248 inserted in a peripheral recess thereof. The cutting blade 248 is effective to cut the strings 14 with each rotation of the wheel 246 with the rotation of the roller and the travel speed of the clasp in the downstream direction 218 coordinated so that the desired predetermined number of clasps 12 is provided. in each assembly. As previously discussed, the assembled clip assemblies 10 can be loaded into a warehouse 250 of an application tool 34 with a front clasp 12a of the collapsed assembly exposed outside the warehouse 250 to be driven by the plunger of the tool 56 to secure around the wire sections 36 and 38 such as the edge wire 252 and a top spiral wire 254 of the mattress coil spring 256 (Figure 42) which are positioned to be secured in a hook jaw member 251 of the toolAs the fasteners 12 herein are used primarily in the mattress and bedding industry, it is important that the plastic cords 14 used in the grooves 16 of the bodies of the individual fasteners 18 do not adversely affect the performance of the product in the which are used. In particular, with spiral springs 256 that are annealed in a heat treatment furnace such as at temperatures between about 232 ° C and 260 ° C with drying times of between 15 and 30 minutes, it is important that the String plastic 14 has the proper cast characteristics, and specifically in terms of flow capacity. It has been found with certain plastic materials that when the small pieces of rope sections cut into the slots of the clasps 16 are subjected to temperatures as found in heat treatment ovens, they tend to accumulate or become pellets leaving a chipote elevated in the outer surface of the clasp 64. ~ The discontinuities along the outer surface of the clasp 64, and in particular those created by raised chipotes, are especially undesirable in the bedding industry and when the mattress material is placed thereon, the discontinuities of the raised chipotes can be felt by the user particularly when the chips are relatively large and / or sharp. In accordance with the foregoing, it is important that the plastic of the ropes 14 does not cause the aforementioned accumulation problem when heated in the heat treatment ovens. It is particularly desirable that the rope material flow so as to disperse outwardly in the slots of the clasp 16 and move toward the interface between the edge wires and the spiral springs 252 and 254 held by the clasps 16 and the surface interior of the clasp 66 so that after cooling and solidification, the plastic material can highlight the clamping power of the clasp 16 on the secured wires 252 and 254. In this regard, polymers that are normally flowable at temperatures about 232 ° C are particularly desirable for use in forming the ropes 14. As soon as this particularly preferred rope material is a polybutylene terephthalate (PBT) material. It has been found that when subjected to heat levels and drying times as found in heat treatment furnaces, the polybutylene terephthalate melts and flows particularly well, such as to connect between the clasps 16 and the secured wires 252 and 254, and does not cause any accumulation problems, as previously described. Alternately, nylon can be used for the rope 14 and run through heat treatment furnaces without causing a ball to be formed on the outer surface 64 of the crown portion of the body of the brooch 20. Although illustrated and Described particular embodiments of the present invention, it will be appreciated that many changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all these changes and modifications that fall within the true spirit and scope of the invention. present invention.
Claims (33)
- CLAIMS 1. A brooch for joining to another identical brooch mediane a resilient rope, the brooch comprising: a of the brooch formed of a metallic material and having an arched portion of crown and dependent leg portions, the brooch having a width of through the crown and a length transverse to the width; at least one groove extending lengthwise in the of the brooch and through its crown portion to define a groove opening for receiving a resilient rope; lateral surfaces of the groove extending vertically through the brooch and having a predetermined spacing in the widthwise direction between them, the predetermined predetermined spacing to create a frictional fit by interference with a resilient rope which is snapped into slot; and at least one projection in a predetermined position along the length of one of the side groove surfaces extending toward the slot opening to maintain a press fit of resilient string towards the slot against displacement out of the slot . The clasp of claim 1, wherein the slot side surfaces include burrs to grip a resilient string to resist movement of a string in the slot in the lengthwise direction. 3. The clasp of claim 1, wherein the at least one slot comprises a pair of identical parallel slots for correspondingly receiving a pair of resilient strings snapped therein. The clasp of claim 1, wherein the at least one projection comprises a pair of opposed projections extending toward the slot opening from predetermined positions along both side groove surfaces toward each other. 5. The clasp of claim 4, wherein the slot includes opposite ends interconnecting the slot side surfaces and the predetermined positions of the projections are generally midway between the slot ends along the respective side surfaces. The clasp of claim 1, wherein the slot includes opposite ends interconnecting the slot side surfaces and having an arcuate shape to provide a seat for a string in the slot. The clasp of claim 1, wherein the slot includes opposite ends interconnecting the slot side surfaces with the ends, each having a V-shape to create an area of weakness in a string snapped into the slot and seated at its V-shaped ends. The clasp of claim 1, wherein the slot includes opposite ends interconnecting the slot side surfaces with the ends, each including a thin edge to create an area of weakness in a tight string. Pressed into the groove and seated on the thin edge of its ends. 9. A collated assembly of attached clasps, each having a of a metal material and including a crown and foot portions dependent thereon, the clasp assembly comprising: slots in the clasp es having slot walls defining openings slotted with adjacent snap es having snap openings that are arranged to be in alignment with each other in the snap assembly; a string of resilient plastic material inserted into the aligned slot openings of adjacent clasps to hold the adjacent clasp es together; and burrs formed in the groove walls for grasping the plastic rope to keep the rope substantially fixed in the groove openings of adjacent brooch es in the brooch assembly to hold clasps attached together in the collated assembly. The clasp assembly of claim 9, wherein the groove walls of each groove include substantially vertical side surfaces that extend parallel to each other and spaced a predetermined distance through the groove opening relative to each other., and the plastic rope has a generally circular cross-sectional configuration with a diameter sized to provide a frictional fit by interference between the parallel side walls. The clasp assembly of claim 9, wherein the slot walls of each slot include opposing projections extending toward the associated slot toward each other to hold the string in the aligned slots against upward and forward displacement of the slots. the brooches. The clasp assembly of claim 9, wherein the rope has areas of reduced diameter spaced along it so that the areas of reduced diameter are disposed between adjacent attached clasps to facilitate the cutting of the rope in that point to separate broaches from the set. The clasp assembly according to claim 9, wherein the slot walls of each slot include side surfaces extending substantially parallel to one another spaced apart through the slot opening one from the other, - and the plastic string has a length and an external contoured surface with a maximum diameter greater than the spacing of the lateral groove surfaces such that the cord is received in the groove by a snap fit despite minor variations in diameter along the length of the groove. rope. 14. The clasp assembly of claim 13, wherein the rope is a striated rope, rope cord, braided rope and helical cord. The clasp assembly of claim 13, wherein the cord is a helical cord having a helical projection or helical depression on its external surface. The clasp assembly of claim 9, wherein the slot walls of each slot include lateral surfaces that extend substantially parallel to each other spaced through the slot opening with respect to each other, and the plastic string has a tubular configuration with a outer diameter which is greater than the spacing of the side surfaces through the slot opening so that the tubular rope is received in the slot by a snap fit. The clasp assembly of claim 9, wherein the rope plastic material is one of polyethylene, polypropylene and nylon. "18. The clasp assembly of claim 9, wherein the plastic rope material comprises a polymer that is generally capable of flowing at temperatures of about 450 degrees Fahrenheit 19. The fastener assembly of claim 18, wherein the plastic material is a polybutylene terephthalate material 20. A die apparatus for forming grooves in a primordial strip of material of a brooch, the apparatus comprising: an upper portion and a lower portion of the die apparatus that are moved toward and away from each other in a groove-forming cycle, a punch carried by the upper portion and having a groove-forming portion; of die in the lower portion having spaced sides sized to receive the groove-forming portion of the punch therein to puncture and know portions of the strip material disposed on the die opening when the die portions are moved towards each other to form a groove in the strip having substantially the shape of the die opening; and projections extending towards the die opening toward each other from the sides of the die opening to limit the pulling of the punctured and spaced portions of the strip material backed with the punch as the die portions move away from each other. The die apparatus of claim 20, wherein the spaced sides extend substantially parallel to each other and the projections each include a surface spaced from the respective sides and extending substantially parallel thereto such that a first clearance is provided between the punch groove forming portion and projection surfaces and a second, larger gap is provided between the groove forming portion of the punch and the sides of the die opening. 22. The die apparatus of claim 21, wherein the second clearance between the punch slot forming portion and the sides of the die opening is oversized to form burrs on corresponding slot sides. 23. A method of forming a collated set of fasteners joined by a resilient cord, the method comprising: feeding a section of a primary metal strip over a die opening in a groove-forming die to puncture slot openings in the strip; providing projections extending to the die opening from opposite sides thereof; driving a punch against the strip section and toward the die opening to punch a slot opening in the strip section so that the slot has sides and projections substantially corresponding to the sides and die projections; - retract the punch from the die opening; restricting strip burrs punched from it being pulled out from the die opening by the die projections as the punch retracts; and inserting a resilient string into grooves of the cut and shaped section in a grooved clasp to join multiple clasps together in a co-located assembly. 24. The method of claim 23, where the string is inserted into the slots by aligning the string over the slot, pressing the string against the slot projections and towards the slot, deforming the string as an incident of oppression of the string against the projections and towards the slot beyond the groove projections, and holding the string in the groove by frictional bonding with the groove sides and with the projections against pulling up and out of the groove further. beyond the projections. The method of claim 23, further comprising providing a first narrow clearance between the punch and the die opening projections and a second larger clearance between the punch and the die opening sides, forming burrs on the sides of the slot as a result of the second over-sized free space, and causing the burrs to grip the string when the string is inserted into the slot. 26. The method of claim 23, further comprising forming ends of the groove interconnecting the sides with a cord-wrapping area, seating a string at the ends of the slot when the string is inserted, and stitching the string with the areas Cutting notch of the slot ends as an incident of inserting the string into the slot and seating it on the slot ends. 27. The method of claim 26, wherein the ends are formed by wedging the material of the clasp at the ends of the slot to provide a thinned area of material at that point. 28. A brooch for joining to another identical brooch and to be fastened around wires to hold together, the brooch comprising: a brooch body having a U shape including a crown portion and dependent leg portions, the body portions of the clasp having external and internal surfaces, at least one slot in the crown portion; and a rope for attaching fasteners together and having a predetermined cross-sectional configuration; the at least one slot defining a slot opening in the crown portion extending therethrough from the outer surface to its inner surface, sized to receive the predetermined configuration of the resilient string by an interference fit, recessed below the outer surface of the crown portion; the rope being made of a plastic material which, when subjected to temperatures of more than about 450 ° F and then solidified, will not be projected onto the outer surface of the crown portion. 29. The clasp of claim 28, wherein the rope material is one of a nylon and a polybutylene terephthalate material. 30. The fastener of claim 28, wherein the cord material is a polybutylene terephthalate material that flows when heated to temperatures about 450 ° F at the interface between the inner surface of the clasp body and the fastened wires and solidifies at that point. 31. A method of making a resilient clasp assembly, which includes the steps of: stamping primordial brooch metal sheet materials, each primordial material having two spaced parallel openings, punched through the metals that will form in a crown of a brooch in the form of ü; forming each clasp around a mandrel to form a U-shaped clasp with a crown portion and two leg portions; placing a plurality of the U-shaped clasps in series, juxtaposed in a line or row with the openings on each side of the clasp in respective alignment to form an extended and continuous opening and on each side of the clasp; placing a flexible filament member in each extended opening; and pressing the filament strip towards each of said openings such that the filament strip is frictionally contacting the lateral edges of said groove, where said filament strips are plastically deformed so as to be maintained mechanically by each side projection of each slot of said pin. 32. The method of claim 31, including the step of forming each groove with rounded ends. 33. The method of claim 32, further comprising the step of making said filament member of a plastic material. Summary A brooch and the set collected from it are provided, and including a method of forming the brooch and the brooch set. The clasp is formed with at least one groove having at least one projection to keep a resilient cord pressed against the groove against forces tending to move it out of it. Preferably, two parallel grooves are provided to receive two cords therein, having two opposing projections extending towards the groove opening from each side of the groove. The groove projections provide a manufacturing benefit - inherent as the punches of the die apparatus that punch pieces of primordial material fed thereto will not suffer from chipping problems due to the presence of corresponding projections extending into the apertures of the die. Die cavity from each of its sides. In addition, although the clearances between the projection of the die cavity and the punches are to normal narrow tolerances, the clearance between the sides and ends of the cavity and the corresponding punches of the clasp slot to grip the cord and provide additional resistance to displacement in the slot. Improved configurations for the cords are also provided to meet the tolerances required for snap fit in the slots and to be easily cut by an application tool. Special shapes for the groove ends can be provided so that the strands press fit there, areas of weakness in the laces will be created to help your cut. Preferred cord materials include those that do not form eyebrows when they are run through spring tempering heat treatment furnaces, such as nylon and PBT.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US942533 | 1997-10-02 | ||
| US039079 | 1998-03-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| MXPA98008124A true MXPA98008124A (en) | 2000-06-01 |
Family
ID=
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6378350B1 (en) | Seat belt anchorage plate for seat belt device and method for manufacturing the same | |
| EP0907033B1 (en) | Slotted clip and method | |
| US5303821A (en) | Resilient clip assembly | |
| CN1120983A (en) | Slide fastener elements and method and apparatus for forming the same | |
| DE60106028T2 (en) | CONTROLLED MATERIAL FLOW IN PUNCH NIET PROCESS | |
| US5303571A (en) | Method of producing a one-piece band clamp | |
| CA1157246A (en) | Method and apparatus for manufacturing slide fastener coupling elements | |
| US4189523A (en) | Sheet metal fastener assembly and method of forming the same | |
| CA1156181A (en) | Method and apparatus for feeding conductive wire for anodizing process of slide fastener chain | |
| MXPA98008124A (en) | Grooved brooch and mét | |
| US4638542A (en) | Method and apparatus for forming element-free spaces in slide fastener chains | |
| EP1845026B1 (en) | Locking clip and method for its manufacture | |
| US1727574A (en) | Staple strip and method of making same | |
| US5878880A (en) | Collated clip assembly | |
| US3685130A (en) | Method and apparatus for gapping and cleaning slide fastener chain | |
| US4054973A (en) | Slide fastener chain with wide gap and method and apparatus for manufacture | |
| DE2608086A1 (en) | COUPLING ELEMENT FOR ZIPPERS AND PROCESS FOR THE PRODUCTION THEREOF | |
| AU2004203306B2 (en) | Improved Pillar Anchor and Method for Manufacturing the Same | |
| EP0205959B1 (en) | Method of and apparatus for removing coupling elements from a slide fastener stringer tape | |
| CN220734602U (en) | Full-automatic multifunctional lower stop machine | |
| US4489456A (en) | Tool for making rivet or expansion nails | |
| GB2180030A (en) | Rivetted structural connection | |
| CN113976758B (en) | Continuous production molding equipment for zipper teeth | |
| EP3705417A1 (en) | A clip for closing sausage casings by constriction | |
| JPH1034253A (en) | Manufacturing method of metal mesh material |