GB2029888A - Snap-fastener element - Google Patents

Abstract

The invention concerns snap fasteners and a method of manufacturing a component thereof consisting of a plastics material head (2a) and a metallic eyelet (3a). The head (2a) has a recess (5a) formed in the under surface into which a flange (12a) of the eyelet is force fitted by pressing to flatten the flange. In use, the shank (11a) of the eyelet (3a) is staked to rivet a socket component (10) of the fastener to the front piece of fabric (20) in the usual way and an eyelet (3b) is similarly used to rivet the male fastener component to the rear piece of fabric to be fastened, again in the usual way. Instead of the eyelet (3a) a known form of pronged eyelet can be fixed to the head (2a). The advantages claimed are ease of manufacture and the fact that with the improved method of attaching the plastics head and the metal eyelet together, a longer life of the resulting snap fastener is obtained. <IMAGE>

Description

SPECIFICATION Snap fasteners and a method of manufacturing a component thereof This invention relates to snap fasteners or socalled "poppers" or press studs, of the kind used for fastening garments, loose covers on furniture, and so on.

A great variety of snap fasteners have hitherto been used. Snap fasteners comprising a male or female component which itself fastens through the material of one part of the garment for example have hitherto had this component molded in one piece of plastics material. Such plastics components present problems in practical use in that they are inferior to equivalent snap fastener components of other materials in piercing a piece of fabric in the process of fastening the fastener component through it. In order to solve this problem, snap fastener components have been proposed which include a metallic eyelet or claw integrally embedded in a plastics head. The plastics headed, metallic press stud thus formed is more readily attached to the fabric by piercing than is the all plastics version because the metal eyelet or claw is better adapted for this purpose.After piercing, the metal eyelet or claw is staked to a female or male snap fastener component, which is thus attached to the back of the fabric. The plastics headed, metallic press studs which are integrally molded together in the manner described also have a problem in practical use. Because of the considerable differences in physical properties and weather resistance between the plastics head and the metallic eyelet or claw, the plastics head can often crack with changes in temperature and/or humidity after molding. Furthermore, the manufacture of these components is difficult and costly.

The present invention provides from one aspect a snap fastener component comprising a head of plastics material and a metallic eyelet or claw for attaching the head to a further component to form one part of a snap fastener, in which the head has a recess formed in its under surface into which a flange of the eyelet or claw has been forcibly fitted thereby to attach it to the head.

The present invention also provides a method of manufacturing a snap fastener component in accordance with the present invention as defined in the immediately preceding paragraph, comprising forming a plastics material head having a recess in its under surface, forming a metallic eyelet or claw having a frusto-conical flange which enlarges outwardly to a peripheral edge, inserting said eyelet or claw into said recess to engage said flange with an inner end wall of said recess, and forcibly pressing said eyelet or claw against said head so as to deform said flange thereof to a flatter shape, whereby said eyelet or claw is integrally attached to said head, with the peripheral edge of said flange thereof engaged securely with a surrounding wall of said recess.

Preferably, said recess enlarges inwardly.

In one form the recess is circular and reduces from a first diameter in said under surface to a second diameter at said inner end wall, and said metallic eyelet or claw is so formed that the outside diameter of said peripheral edge enlarges from a first diameter to a second diameter during said pressing step, the second diameter of said peripheral edge being greater than said second diameter of said recess.

Preferably, the first diameter of said recess is greater than the first diameter of said peripheral edge.

The snap fastener component in accordance with the present invention has the advantage of being simply manufactured by mass production techniques. The metal eyelet or claw is readily capable of piercing a fabric garment piece when it is to be used to fit a snap fastener part thereon, and because of its construction the head will last without cracking and yet be fitted securely to the garment or the like with small possibility of coming off.

Specific embodiments of the present invention in both its method and product aspects will now be described by way of example, and not by way of limitation, with reference to the accompanying drawings in which: Figures 1 and 2 are diagrammatic sectional views of prior art snap fastener components corresponding with those of the present invention before being used to fit a snap fastener part to a garment or the like; Figure 3 is a diagrammatic sectional view of the component of Fig. 1 after having been used to fit a snap fastener part in place; Figures 4 and 5 are diagrammatic sectional views of another corresponding component of the prior art before and after being used to fit a snap fastener part in place; Figure 6 is a sectional view of a plastics material head for use in practising the present invention;; Figure 7 is a diagrammatic sectional view of a snap fastener component made in conformity with the invention and using the head shown in Fig. 6; Figures 8a and 8b are diagrammatic sectional views of a metallic eyelet and a metallic claw for use in practising the invention; Figure 9 is a fragmentary sectional view of the plastics material head of Fig. 6, shown on an enlarged scale; Figures 10 and ii are diagrammatic sectional views of a plastics material head and a metallic eyelet which illustrate steps in a method of manufacturing a snap fastener component in accordance with the present invention; Figure 12 is a diagrammatic sectional view of a further form of metallic eyelet to be used in practising the invention;; Figure 13 is a diagrammatic sectional view of a further snap fastener component made in accordance with the present invention using a metallic eyelet of Fig. 12; Figure 14 is a diagrammatic sectional view of a still further form of metallic eyelet for use in the practice of the invention; Figure 15 is a diagrammatic sectional view of a still further snap fastener component made in accordance with the present invention using a metallic eyelet of Fig. 14; and Figures 16 to 19 are cross-sections showing different snap fasteners according to the present invention.

Referring first to Figs. 1 to 5, a snap fastener has a front part made of two components 1 and 10 in Fig. 3 or 1" and 10" in Fig. 5. The component part, indicated 1, 1' or 1" in Figs. 1, 2 and 3 respectively consists of a head 2, 2' or 2" of plastics material and a metal eyelet 3, 4 or 3', 4' or again a metal claw 3", 4" which is in the form of an eyelet in which the hollow cylindrical wall 3 or 3' constituting the shank portion is formed by a series of circumferentially spaced prongs, e.g.

five prongs 3", seen in Fig. 4. The eyelet or claw is integrally embedded in the head 2' or 2" during molding of the head in Figs. 2 and 3. In Fig. 1 the flange 4 of the eyelet is wrapped round so as to embrace the plastics material head 2.

The front part of the snap fastener is attached to one piece of fabric 20 of a garment for example by piercing the fabric from the front with the shank portion 3 or 3' of the eyelet or with the prongs 3" and then staking the shank portion or the prongs to a socket component 10 or 10" thereby to attach the socket component of the fastener securely to the back of the fabric 20. The socket component then secures the head 2, 2' or 2" securely to the front of the fabric 20.

With reference now to Figs. 6 to 1 9 of the accompanying drawings, a snap fastener component corresponding with that shown in Fig.

1, 2 or 4 and in accordance with the present invention is shown in Fig. 7 and consists of a molded, plastics material head 2a and a metallic eyelet 3a fitted in a recess 5a in the under surface of the head. The metallic eyelet takes the form shown in Fig. 8a but instead it may take the form of a five pronged claw as shown in Fig. 8b. The head 2a is decoratively finished on its upper surface with a design as desired. The opposite surface, or the under surface, is formed with the recess 5a (Refer to Fig. 6). As best shown in Fig. 9, the recess 5a is desirably formed so as to be wider at its inner end i.e. as measured across its inner end wall, than at its opening flush with the under surface of the head, that is to say, the recess enlarges inwardly, its side wall tapering at an angle A.Referring to Fig. 6, this relationship is d2 > dt where d1 and d2 are the minimum and maximum diameters of a circular sectioned recess employed. The angle A should be within the range that permits the molded plastics head to be released from the mold. As shown in Fig. 8a, the metallic eyelet consists of a hollow cylindrical shank 11 a and a frusto-conical flange 1 2a formed in one piece with the shank and which enlarges outwardly to a peripheral edge.The outside diameter of this edge is desired to be such that a relationship D2 > d2 > d1 > Dl holds, in which D1 is the outside diameter of the flange before being fitted in place, as in Fig. 8aor 8 b, D2 is the diameter of the flange fitted in place as in Fig. 7, d1 is the diameter at the opening of the recess 5a of the plastics head 2a, and d2 is the diameter at the inner end of the recess. The numerical values may be given, as an embodiment, as below: d1 = 8.9 mm d2 = 9.4 mm A = about 20 deg.

D1 = 8.7 mm D2=9.5 mm Fig. 8b shows a metallic claw which may be used instead of the eyelet of Fig. 8a and in which the hollow cylindrical shank portion is formed by a series of five circumferentially spaced prongs 11 a forming the hollow cylindrical wall in this case.

In manufacturing the snap fastener components of the present invention, each plastics material head 2a and metallic eyelet or claw 3aformed to the shape and size as defined above are placed together, with the recess 5 a of the head and the flange 1 2a of the eyelet or claw facing each other. (Fig. 10). Next, the flange 1 2a of the eyelet or claw is inserted into the recess 5a of the head 2a until the outer peripheral edge of the flange touches the inner end wall of the recess 5a (Fig. 11).

The eyelet or claw 3 a is then pressed against the head 2ato obtain a force fit. Consequently, the frustoconical flange 1 2a of the metallic eyelet or claw 3a is permanently deformed to a flatter shape or flattened, as indicated in Fig. 7. Since the diameter d2 at the inner end of the recess 5a of the head 2a is slightly less than the outside diameter D2 of the metallic eyelet or claw 3a in the flattened state, the peripheral edge region of the eyelet or claw plastically fits in, or partly bites into, the surrounding frusto-conical wall of the recess 5a. The metallic eyelet or claw 3a is now securely fixed to the head 2a. The force fit of the metallic eyelet or claw in the recess of the head, accomplished in the manner described, enables the head to maintain a firm hold on the eyelet or claw, the bite of the metal into the plastics material and the relative rigidity of the metal ensuring the formation of firm con nection between the metallic eyelet or claw and the plastics material head without any cracking of the latter.

The component integrally made up in this way is subsequently secured to an article of clothing or the like using a socket component 10 or 10" as shown in Fig. 3 or 5 to form the front part of a snap fastener as shown in Fig. 16 or Fig. 18.

While the flange 1 2a of the metallic eyelet or claw 3a has been described as an extension direct from the cylindrical or claw-like shank 11 aas illustrated in Figs. 8aand 8b, it is also possible to interpose therebetween an intermediate flange 1 3a of any desired contour as shown, for example, in Figs. 1 2 and 14. Figs. 1 3 and 1 5 show snap fastener components in accordance with the invention made by incorporating metallic eyelets 23a and 23a' shown in Figs. 12 and 14.It will be seen that unlike the flange 1 2a of the component shown in Fig. 1 3 the flange 1 2a of the eyelet in Fig. 1 5 is not completely flattened.

The method of manufacturing snap fastener components in accordance with the invention has the advantage of simplicity and adaptability for mass production.

In addition, the components easily pierce a fabric to be fastened when they are fitted thereon, and serve their purpose for a long time without cracking of the plastics material head. Furthermore, the components fit securely to the fabric and do not easily come off.

Figs. 1 7 and 1 9 show snap fasteners having headed components 1 a of the invention used to secure male components 10bat the rear of the front piece of fabric 20 to be fastened. In this case sockets 10 are secured to the rear piece of fabric 20b, in Fig. 1 7 with an eyelet 36 having originally a hollow cylindrical shank and in Fig. 19, with a claw 3b having a shank formed by five prongs as described above.

Figs. 1 6 and 18 likewise show rear parts for the snap fasteners fixed to rear pieces of fabric 20b and conprising a male snap fastener component and an eyelet or claw 3b fixing it to the fabric.

The head of plastics material is preferably formed in each case from polyacetal resin, for example, that marketed by E.I. du Pont de Nemours a Co. Inc., of the U.S.A., under the trade mark DELRIN-500. However, it is believed that nylon would also be suitable.

Claims (9)

1. A snap fastener component comprising a head of plastics material and a metallic eyelet or claw for attaching the head to a further component to form one part of a snap fastener, in which the head has a recess formed in its under surface into which a flange of the eyelet or claw has been forcibly fitted thereby to attach it to the head.

2. A snap fastener component as claimed in claim 1 in which said recess enlarges inwardly.

3. A snap fastener including a component as claimed in any preceding claim.

4. A method of manufacturing a snap fastener component as claimed in claim 1 comprising forming a plastics material head having a recess in its under surface, forming a metallic eyelet or claw having a frusto-conical flange which enlarges outwardly to a peripheral edge, inserting said eyelet or claw into said recess to engage said flange with an inner end wall of said recess, and forcibly pressing said eyelet or claw against said head so as to deform said flange thereof to a flatter shape, whereby said eyelet or claw is integrally attached to said head, with the peripheral edge of said flange thereof engaged securely with a surrounding wall of said recess.

5. A method as claimed in claim 4 in which said recess enlarges inwardly.

6. A method as claimed in claim 5 in which said recess is circular and reduces from a first diameter in said under surface to a second diameter at said inner end wall, and said metallic eyelet or claw is so formed that the outside diameter of said peripheral edge enlarges from a first diameter to a second diameter during said pressing step, the second diameter of said peripheral edge being greater than said second diameter of said recess.

7. A method as claimed in claim 6 in which the first diameter of said recess is greater than the first diameter of said peripheral edge.

8. A snap fastener component as claimed in claim 1 when made by a method as claimed in any one of claims 4 to 7.

9. A snap fastener component substantially as hereinbefore described with reference to, and as shown in, Figs. 6, 7 and 8a and 9 or Figs. 6, 7 and 8band 9 or Figs. 12 and 1 3 or Figs. 1 4 and 1 5 of the accompanying drawings.

1 0. A snap fastener substantially as herein before described with reference to, and as shown in, Fig. 16 or Fig. 17 or Fig. 18 or Fig. 1 9 of the accompanying drawings.