US2496130A - Method of casting separable fastener stringers - Google Patents

Description

Jan. 31,, 195%!) 1 H. MORIN z9496vfi3w METHOD OF CASTING SEPARABLE FASTENER STRINGERS Original Filed May 23, 1942 INVENTOR [00/5 bf flaw/v BY 7 W ATTO NEY Patented Jan. 31, 1950 iJlTED 'iA'ilES PATENT FFIQ METHOD OF CASTING SEPARABLE FASTENER STRINGERS ceased Qriginai application May 23, 1942, Serial No. 444,191. Divided and this application August 22, 1945, Serial No. 612,091

1 Claim. 1

This invention relates to separable fasteners employing stringers adapted to be coupled and uncoupled. More particularly, the invention relates to a method of simultaneously casting two or more links or scoops of a fastener of this kind upon a tape or other mounting and a core element and further in stripping or otherwise removing the core element from the castings, The novel features of the invention will be best understood from the following description when taken together with the accompanying drawing, in which certain embodiments of the invention are disclosed, and in which the separate parts are designated by suitable reference characters in each of the views; and in which:

Fig. 1 is a diagrammatic sectional view illustrating the method of forming a pair of links or scoops on a mounting member.

Fig. 2 is a perspective view of two of the scoops shown in Fig, 1 indicating the core removed and showing the form of gate employed.

Fig. 3 is a side and sectional view of a part of a stringer showing another type of link or scoop and indicating the method of producing the same.

Fig. 4 is a view similar to Fig. 3 showing another form of link or scoop.

Fig. 5 is a diagrammatic view illustrating the type of gate employed in casting end links.

Fig. 6 is a view similar to Fig. 5 illustrating the method of casting a multiplicity of links; and

Fig. '7 is a diagrammatic View showing the spacing between successive groups of castings.

This application constitutes a division of my prior application, Serial No. l4=l,l91 filed May 23, 1942 and issued January 8, 1946, as Patent Number 2,392,684.

In the die casting of links or scoops of sepa rable fasteners of the well known kind employing stringers and a slider movable along the stringers to couple and uncouple the same, it has been the common practice to cast the links or scoops one at a time and this has been essential in order to form the male and female interlocking portions on the scoops and particularly the undercut female portion, Many attempts have been made to die cast a multiplicit of links or scoops in forming complete stringer lengths but such attempts have been impractical and inoperative or have presented such outstanding difficulties as to result in the production of stringers which were not commercially practical.

After lon and careful study and experimentation, the desired objective, namely castin of .2 two or more similar links or scoops, has been accomplished in a commercially practical manner by utilizing a common core element to form the undercut or female coupling portion of all of the links and either stripping this core element from each group of links and utilizing the same for casting the next successive group, or in using a separate core element for each group of castings and afterwards removing the same from the links or scoops, as more fully herein after set forth.

In order to diagrammatically illustrate the general method employed in forming castings of the kind under consideration, I have indicated in Fig. 1 one-half of the die i a in which is formed one-half of the two similar cavities or impressions i l shaped to form a pair of links it as well as the gate 13 through which metal from an injector nozzle M is pressure injected into the cavities H. The ends are also provided with recesses or cavities l5 for the reception of the mounting member or tape it and with another cavity I! for the reception of the core element 18.

The method of forming the pairs of castings I2 will be readily understood from the foregoing and the following description. When both parts of the die II] are in open position, the mounting member 16 is arranged between adjacent surfaces thereof, as is also the core element iii. The die parts are then brought into firm engagement with each other and at this moment heated casting material, which may be metallic or plastic, is pressure injected through the nozzle M, in forming the castings !2 simultaneously on the mounting member 46 and around the core element i8 and filling the gate it. The dies are then opened; the core element 18 and tape [6 are moved downwardly bringing the first cast pair of links I 2 into the position indicated at (9 in Fig. 1, after which the core element It is stripped from the castings, moved up to its original starting position, after which the dies are again closed and the above operation repeated. In the stripping operation, the uppermost link 12 of the first cast pair of links is arranged adjacent the lower surface- 20 of the dies and this serves as means to properly space the successive pairs of links on the mounting member [6. It will appear that the gate passage has an initial opening 2! which branches upwardly and downwardly as indicated at 22 and the latter terminates in yokes 23 which encircle half of the core element 13, note Fig. 2 of the drawing.

The above operation of casting pairs of links or scoops on the mounting member i5 repeated until such time as a predetermined series of links have been formed on the mounting member, after which the mounting member may be independently fed to produce a wide spacing thereon to space successive series of links in forming what is ten ied stringer or chain lengths as is known in the art.

Each link [2 is of the same construction and comprises upwardly and downwardly extending triangular projections 2e adapted to enter corresponding recesses in links of an opposed stringer when the stringers are coupled together. On the outer surface of each link, the core element it forms an arch-shaped recess 26 which will engage correspondingly formed projecting elements 2i arranged in the recessed portions 25 of the opposed stringer links. In other words, the links or scoops 12 are what I term double acting type, both upper and lower surfaces being of identical construction which permits coupling of the links by a slider movable in both directions on the stringers, In other words, it is immaterial which way the slider is positioned on the stringer to produce the coupling engagement and, of course, the same is true for the uncoupling of the stringers. This construction further adapts the stringers for the use of two sliders operating on a single pair of stringers or chains.

At this point, it is well to bring out the distinct advancement in the art which is accomplished by the conception of the method to produce let us say, for example, two links or scoops in one casting operation. Heretofore, individually cast links or scoops have been commercially produced at the rate of approximately 350 castings a minute, although higher speed castings have also been produced. But on the basis of 350 per minute, it will readily appear that by simultaneously casting two links or scoops in each casting operation, the production has been increased one hundred per cent. In like manner, by casting three links or scoops at one time this production will be increased two hundred per cent. From a practical standpoint the size of the link or scoop will govern to some degree the practicability in casting, according to the teachings in Fig. 1 of the drawing, the predetermined number of links. For example, with the smaller size links a larger number of links may be formed in each casting operation, by this I mean, in the process where a complete stringer length or chain is made up of a series of multiple castings.

Where short stringer lengths are required, all of the links of the complete stringer length may be cast in one operation, as more specifically described hereinafter. On the other hand, where extremely long stringers are required, these long lengths may be cast in multiple groups, and where the groups are comparatively long, a single core element may be used for all groups on each stringer length.

With the construction shown in Figs. 1 and 2, the core element 58 is arranged upon the outer surface of the links or scoops to form the resulting recesses or undercut sockets 26. Instead of this method of procedure, I have illustrated in Fig. 3 of the drawing another method which comprises arranging a core element 28 inwardly of the outer surfaces 29 of a pair of links or scoops 3G and centrally of the projecting portions 3i which are equivalent to the portions 24. With this type of construction, sockets or apertures 32 are formed through the links or scoops which are 4 adapted to receive projecting couplings 33. centrally of the recess portions 34 thereof. In other words, with this type of link the apertures or sockets 32 receive the projections 33 of the links or scoops of the opposed stringer when the stringers are coupled together, in the same manner as the engagement of the projections 2'! with the recesses 26. With this method of procedure, the gate 35 simply has two extensions 35 which are disposed on the surfaces 2% of the links. At this time, it will be well to mention that the gates are removed from the links in the production of the resulting fastener stringers in what is generally known as the trimming operation.

In Fig. 4 of the drawing is shown another method of procedure wherein the core element 31 forms in the links 38 apertures 39 which are arranged inwardly of projecting portions 4!) disposed on upper and lower surfaces of the links or scoops outwardly of the apertures 39. With this construction, it will be apparent that the projections ii! of the links or scoops of one stringer will engage the apertures or sockets 3Q of the links or scoops of the opposed stringer. The gate M of Fig. 4 is the same as the gate Eli of Fig. 3.

From a comparative consideration. of the structures, as seen in Figs. 1, 3 and 4, it will be apparent that in Fig. l the core element is disposed outwardly of the projecting elements of the scoops. In Fig. 3 it is disposed centrally of the projecting elements of the scoops; whereas in Fig. 4 it is arranged inwardly of the projecting elements. These illustrations are simply to show general adaptations of the invention without limitation to the particular structure of each link or scoop.

In Fig. 5 of the drawing, I have diagrammatically illustrated the general form of gate which may be utilized in simultaneously casting three links or scoops. In this figure, :2 represents the gate which has three branches 53 leading to the resulting three castings, partially indicated at 44, these castings being all formed on a single core element 45. It will thus appear that if four castings are formed, four branches will be provided in the gate instead of three.

In Fig. 6 of the drawing, I have diagrammatically illustrated a short section of a complete gate arrangement which would be utilized in forming a large number of links or scoops or a complete stringer length. The gate in this construction will have an admission portion 45 opening into a large distributing portion 41 from which there will be a multiplicity of independent branches 48 leading to the individual links or scoops 49 all arranged on a core element 50.

In forming complete stringer lengths which are comparatively short, it would be desirable to form these complete stringer lengths on individual core elements 5! as is indicated in Fig. 7 of the drawing, the elements being spaced apart at the wide spacing portions 52 of the tape or mounting member which subdivide the complete stringer lengths from each other. For example, the stringer length 53. diagrammatically shown in Fig. 'l, is spaced from the end stringer lengths as, 55. Where very long stringer lengths are required, a long strand may be used as the core element 5! and this strand will be continuous through the multiple groups of castings to form the complete stringer length and if desired may continue or bridge across the spacing between the long stringer lengths. With this type of construction, it would be desirable to employ a core element havin flexible characteristics.

In some instances and particularly where the core element is used as a means for feedin groups of links, for example, as is referred to in Fig. 1 of the drawing, it is preferred that the core element comprise a relatively rigid body prefcrably of metal. In all other instances, however, the core element may comprise, for example, an endless strand of wire, along which may be formed the successive group castings or this core element may comprise a flexible and yet substantially firm strand of any type or kind so long as it is possible to strip or otherwise remove the core element from the resulting castings. In some instances a very low melting point metal may be used and in other instances materials capable of being chemically or otherwise removed would also be practical. The only precaution that is required is to use a strand-like element for the core which will have a surface which will provide free removal of the element from the resulting casting without marring or obstructing the casting.

In forming complete stringer lengths on a long mounting member, it will be understood that means will be provided to feed the mounting member to successively bring spaced sections thereon in position between the multiple impression dies employed for forming on the mounting member sections of the complete stringer length. On the other hand, where the complete lengths are made from series of group castings, the mounting member will be fed to bring the groups of castings into proper spaced relationship to each other so that adjacent links of each group, in a complete stringer length, will be properly spaced with respect to each other in the same manner as taught in the series of links formed as illustrated in Fig. l of the drawing.

It will also be apparent that the gate portions of the resulting castings which are removed by trimming or other operations are reheated or melted so that these gate portions do not amount to waste. Therefore, the size of these gate portions is of no particular consequence from a standpoint of production cost.

In all instances, the dies employed will be cooled in accordance with known methods and no detail showing is required in this respect as it is quite old in the art of forming pressure die castings.

From the foregoing, it will be apparent that my improved method, in addition to materially speeding up the production of products of the kind under consideration, in a more specific sense may be said to comprise the steps of simultaneously forming two or more castings by the use of a single core element. The socket or female portions of the links or scoops serve for the reception of projecting coupling elements which retain the coupled links or scoops against separation. Furthermore, two or more identical link or scoop structures are formed.

It is also preferred that each part of the die include an auxiliary stripping element 56, as seen in Fig. 1, which will engage the lower link of the pair of links in removing the core. In stripping long core elements from a multiplicity of castings, a suitable jig or fixture will be used to receive the links or scoops so that all of the links or scoops will be supported in this pulling or stripping operation. In stripping the core element l8, as taught in Fig. 1, the operation is performed while the dies are in a partially open position and the cavities of the dies support the links or scoops in this operation. In other words, after the dies are first opened, to move said cast links and tape to the position IS, the dies are partially closed.

In casting a plurality of links or scoops, it is, of course, not essential that these scoops be formed directly upon a tape or other mounting and may be simply cast on the long core element which will maintain the castings in desired spaced relationship to each other and the castings thus formed and arranged can be applied to any suitable mounting. It will be understood that a core element will be provided in the dies for forming the forked or U-shaped ends of the links or scoops to receive the mounting. In employing core pins or elements for the multiplicity of cast links or scoops having coatings thereon to facilitate removal, coatings such as graphite may also be used.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is:

The method of producing separable fasteners employing stringers with scoops spaced longitudinally thereof, which comprises simultaneously die casting in a pair of dies a plurality of complete scoops, each scoop including a tape gripping portion and a coupling portion, in spaced relation on a preformed core element; removing the core element including the scoops thereon from the dies; directly applying said scoops to a tape by attaching the tape gripping portion of each scoop directly to the edge of said tape; removing said core element from all of the scoops, and then trimming all of said scoops.

LOUIS H. MORIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,307,410 Kuna Jan. 5, 1943 FOREIGN PATENTS Number Country Date 391,146 Great Britain Apr. 18, 1933

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