US2106129A - Method of making separable fasteners - Google Patents

Description

Jan. 18, 1938. e. SUNDBACK 2,106,129

METHOD OF MAKING SEPARABLE FASTENERS v Filed Feb. 4, 1955 2 Sheets-Sheet l Jan. 18, 1938. asuNDBAcK 2,106,129

METHOD OF MAKING SEPARABLE FASTENERS Filed Feb. 4, 1935 2 Sheets-Sheet INVENTOR. Gideon Sundbac k srA'rEs METHQD F MAKINERSSEPABABLE FASTEN- Gideon Snndback, Meadville, Pa., assignor to Talon, Inc., Meadville, Pin, a corporation of Pennsylvania Application February 4, 1935, Serial No. 4,794

12 Claims.

My invention relates to the art-of making fastener stringers, particularly for fasteners of the type'having multiple series of spaced elements attached along the corded edge of a flexible tape. A pair of such fastener stringers are usually fitted with a slider for engaging and disengaging the fastener elements.

This application is a continuation in part of my copending application, Serial No. 414,156, filed December 14, 1929, now Patent No. 1,992,- 253, dated February 26, 1935,- in which there is disclosed a new and improved form of wire fastener element, for the making of which my invention is especially adapted. It is to be understood, however, that the method invention claimed in this application is not limited to any particular form of element since the interlocking construction as well as other features may be varied in many ways.

Slide fastener stringers have been manufactured by various methods in most of which a fiat metal blank is cut out with spaced clamping jaws for attaching the element to a stringer, and with a head at the other end. After the blank is out it is usually placed in a suitable die and by operation of a reciprocating punch a projection and recess are formed on the head end.

An important object of this invention is to provide a slide fastener whose elements are smooth and free from so-called tool marks and other uneven surfaces.

In the ordinary die forming of a blank which has been punched out of sheet metal, during the operation in which the recess and projection are simultaneously formed, the metal swells in all directions, causing uneven outer surfaces. This is particularly true after the die has become somewhat worn.

Furthermore, the original surface of a blanked element or of one which has been severed from a formed wire may be uneven or, at least have uneven and sharp corners. By using the original surfaces of a wire as the finished external surfaces of the fastener elements-I am able to secure a smoother fastener than has been known before.

In my improved method the projection and recess are formed in distinct and separate operations. One advantage of this is that the entire thickness of the metal is not placed under heavy forging pressure which would cause swelling and distortion of the outer surfaces of the fastener member.

Another object of theinvention is to provide a method of making the'recess and projection at the bend in a wire fastener element whether the wire be round or square, in such'a way that the placing of metal will not materially weaken the fastener element at the bend. It will be understood that this might easily proveto be the weak point of the fastener since the clamping effect of the jaws depends on the strength of the element at the bend. I

My invention also contemplates a new sequence of steps in making fastener stringers. Instead of forming the elements with the desired interlocking projections and recesses before attaching them to the tape, the blanks are first secured firmly to the tape in properly spaced relation, and then the interlocking projections or recesses, or both, areformed. In this way the problem of locating and holding the small elements while being operated upon by punches and dies is simplified.

Various other objects and advantages of my invention will appear during the following specification and will be particularly pointed out in the claims.

In the accompanying drawings, I have shown for purposes of illustration. two embodiments which my invention may assume in practice. In these drawings: 7

Figs. 1 and 2 are diiferent views .of a wire blank used in making a fastener element from round wire;

Fig. 3 is a plan view of a small section of fastener stringer after the wire blanks are secured thereto andbefore the interlocking means are formed;

Fig. 4 is a transverse section through the stringer in Fig. 3; v

Fig. 5 is a perspective view showing diagrammatically the tools for, forming the interlocking recess; I

Fig. 6 is an elevation view showing diagrammatically the tools for forming the interlocking projection; r

Fig. 7 is a longitudinal section through a small portion of a fastener showing the construction of a typical fastener element .formed from round wire; 7 Y

Fig. 8 is a transverse section through the fastener showing the projection side of the element; I

Fig. 9 is a front view of a fastener element;

Fig. 10 is a plan view of a completed fastener made in accordance with my invention with the top portion of the slider removed to facilitate illustration;

Fig. 11 is a cross-section through the die with Figs. 13 and 14 are various steps in a modified method wherein a wire of square cross-section is preformed and cut 011;

' the tape 2| with its attached U-shaped blanks Fig. 15 shows the wire in cross-sectio with the preforming tools diagrammatically illustrat- ,ed;

Fig. 16 is a perspective view of the preformed wire element ready for bending;

Fig. 1'7 shows the next step of the method wherein the blank is bent to U-shape;

Fig. 18 shows the step of forming the recess and also the step of forming the projection;

Figs. 19 and 20 show the following step of forming the clamping jaws;

Fig. 21 shows the step of spreading the jaws and Fig. 22 shows the last step of. closing the jaws on the beaded edge of a tape; and

Fig. 23 is a view of a slide fastener made ac-. cording to the second embodiment of the invention. A

Referring to Figs. 1 and 2, a blank II is cut from a piece of round wire and formed with suitable means such as indentations l2 adjacent the ends of the blank to engage around the corded edge of the tape when the member is clamped to the stringer. In this form the wire blanks may be tumbled to remove all burrs and hoppered by any suitable mechanism such as described in my Patent No. 1,653,320. The indentations I! may, if desired, be formed at some latter stage of production such as described in said patent.

In this embodiment of the invention the next step comprises bending the wire blank around. 'the corded edge 20 of a stringer 2| and thus securing the blanks firmly to the stringer in the proper spaced relation for the finishedfastener elements. The, member in this form comprises U-shaped element with clamping sides or legs l3, l1 and a bend l5. It is now necessary to form the interlocking projection and recess at the bend II. There stepsmay occur simultaneous or either may precede the other.

Fig. 5 illustrates the forming of the recess. During this operation it will be understood that having a forming end 25 which moves into the blank at an acute angle between a pair of adjacent elements on the stringer. By reason of this kind of movement the material which is displaced. to form the recess It, moves inwardly toward the inside of the bend as seen in Fig. '7 whereby the resulting structure is not weakened.

The forming of the interlocking projection is 'shown in Fig. 6. The side operating tools 28 and and 26a enter: between the blanks along the stringer and support each of the elements in turn while the projection is being formed. The tool for forming the projection is indicated by the numeral 21 and is provided with a suitable forming edge which pushes downwardly the material on the outer front surface of the blank ps0 as to form a projection l'l. 'Only a small amount of material need 'be moved in this operation so that, the resulting member is not materially weakened. By forming the projection and recess in two separate operations, the shape and size of the one is not controlled by the other.

This method results in a fastener as shown in Fig. 10, having interengaging recesses and projections l6 and i1 respectively, and sloping front end surfaces l8, which assist in guiding the members into engagement with one another.

strength materially, is however, common to both methods.

In the second method I start with a wire 3| of square cross-section, it being understood that the corners will have a substantial radius in order that they will be smooth to the touch.

. A section of this shape may readily be formed by extruding or by simple rolling operations.

The first steps are the cutting of the wire into individual lengths and the preforming ofthe wire to provide recesses '32 having an unsymmetrical shape, as illustrated. This preformlng mayibe done. before cutting .of the blanks or afterwards, by suitable reciprocating tools, such as illustrated at .33 and 30 or by rotary die members. These recesses are formed so as to extend across one corner of the wire section and the forming ofthese recesses leaves a portion .of metal 36 in the middle which has been somewhat enlarged during the forming of the recesses. After bending of this preformed element into the'shape shown in Fig. 17, the portionof metal" is left at the bend and can be utilized for forming the projection. The forming of the projection and recess is indicated in Fig.18, and is'carried out by suitable forming tools 36, 31, which act similarly to the forming tools 21. 24 respectively in the first method.

The next step as illustrated in Fig. 19, comprises punching out therecesses 38, 39 leaving one leg ll of the bent member thicker than the' other leg I. The'punch and die which cut out the recesses 38, 39 are, of course, slightly ofl center with respect to the fastener element. The punch and die are indicated at 2, 43. This punching out operation leaves the surfaces on the inside of the legs 40 and ll very rough with burred edges which tend to make the legs more securely grip the corded edge-of the tape when clamped thereto, holding the fastener members in place, thus eliminating any danger of the members slipping out of place along the corded edge. It is now necessary to spread these legs or at least one of them before placing the members on the cordededge of the tape. In the spreading operation, preferably only the leg 40 is bent as shown in Fig. 21. The final step comprises closing of this leg 43 around the corded edge of the tape 2| by any suitable tools, one of which is illustrated at M. It has .a somewhat different appearance from the fastener of Fig. 10 inthat the sides will.

be fiat and smooth. All rough corners and-burrs.

however, can be removed by tumbling of the.

members either in the form shown in Fig. 16 or wire leaves side sloping surfaces 43 which make the fastener more easily flexible without becoma Fig. 17. In this fastener the preforming of the e ing a piece of material from original uniform.

ing disengaged. The slider for operating this fastener is indicated by the numeral 46.

While I have specifically shown and described in this application two embodiments which my invention may assume in practice, it will be understood that these embodiments are merely for the purposes of illustration and descriptio isand that various other forms may be devised within I the scope of my invention as defined in the following claims.

What I claim as my invention is:

l. The method of making fastener elements comprising forming attaching means on each fastener member for securing it to a tape, a portion of the member being adapted to project beyond the attaching means, punching out a recess in one side of such projecting portion of said member, and deforming material from an outer surface of said member to provide a projection opposite said recess.

2. The method of making a fastener element comprising forming a clamping portion adjacent one end of the element, providing interlocking means at the other end by steps including punching out a recess on one side of said element with a punch moving at an acute angle to the plane of said element so as to deform the material from said recess in the plane of said element in a direction toward the clamping portion? .1"

3. The method of making a fastener elemen comprising bending a piece of wire to form clamping portions between the ends of the wire, deforming material from adjacent the bend toward said clamping portions to form a recess, and forming an interlocking projection, on the bend of said wire.

4. The method of'making a fastener element comprising bending a piece of substantially round wire to form parallel side portions and a connecting portion at the bend, deforming material, wholly from the outer side of said bend on then front of said element to form a' projection on one side of said connecting-portion, and punching out a recess wholly in the other side of said connecting portion.

5. The. method of making a fastener stringer which comprises cutting a plurality of blanks, attaching them in spaced relation to the edge of a piece of material, and deforming the material of each of said blanks while so attached to form interlocking projections and recesses.

16. The method of making fastener stringers for slide fasteners which comprises securing fastener member blanks to said stringers along the adjacent edges thereof, said blanks being of the approximate size and shape of the finished fastener element and having the same spacing as the elements of a finished fastener, and then operat ing on the projecting portions of each of said blanks to complete the formation of interlocking projections and recesses.

7. The method of making a fastener elementfor attachment to 'a flexible stringer inthe manu 'facture of slide fasteners, which comprises forgcross-section to concentrate material at the cen-' tral portion of said piece of material, bending said piece of material to U-shape with said eoncentrated portion at the bend, the legs of said 5 U-shaped member constituting means for em-.

bracing and'clamping the edge of a stringer, and

deforming material at said bend after the bend-' ing operation to provide an interlocking projection and recess. a

8. The method of making a fastener element for attachment to a flexible stringer in the manufacture of slide fasteners, which comprises forging a uniform piece of material from" uniform cross-section to concentrate material at the cen- 15 tral portion thereof and to provide indentations on opposite sides of said enlarged portion, bending said piece of material to U-shape with said enlarged portion at the bend, the legs of said U-shape member constituting means for embrac- 20 ing and clamping the edge of a stringer, and deforming material at said bend after the bending operation to provide an interlocking projection on one side and an interlocking recess on the opposite side. 25

9. The method of making a fastener element for attachment to a flexible stringer in the manufacture of slide fasteners, which comprises forging a uniform piece of material from uniform cross-section to concentrate material at the central portion thereof and to provide indentations on opposite sides of said enlarged portion, bending said piece of material to U-shape with said enlarged portion at the bend, forming recesses in the opposed faces of the leg portions of said bent member to provide means for engaging the beaded edge of a flexible stringer.

10. The combination defined in claim 10 with the further step of spreading said legs apart to facilitate assembly with the beaded edge of the 40 flexible stringer.

'11. The combination defined in claim 10 wherein the recess in one of said leg portions is deeper than the opposite recess to make one leg weaker against bending stresses than the opposite leg.

12. The method of making fastener elements for attachment to a flexible stringer in the manufacture of slide fasteners which comprises forging a piece of material of generally square cross-section to provide an enlarged portion at 50' the middle with material concentrated along one corner of said piece of material, and to form indentations extending across the same corner, and the opposite sides of said enlarged portion, bending said piece of material to Usha'pe in sucha way that-the parallel legs of the bent member have flat faces opposite each other and with said enlarged portion at the bend, and then forging the material at said enlarged portion to provide an interlocking projection on one side of the 50 member and forming an interlocking recess on the opposite side of said member.

GIDEON SUNDBACK.

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