GB1558611A

GB1558611A - Sliding clasp fastener

Info

Publication number: GB1558611A
Application number: GB3035676A
Authority: GB
Original assignee: Opti Patent Forschungs und Fabrikations AG
Current assignee: Opti Patent Forschungs und Fabrikations AG
Priority date: 1975-07-22
Filing date: 1976-07-21
Publication date: 1980-01-09
Also published as: FR2318599A1; DE2532683A1

Description

(54) SLIDING CLASP FASTENER (71) We, OPTI PATENT-, FORSCHUNGS UND FABRIKATIONS-AG, a company organised under the laws of Switzerland, of Burgstrasse 24, Glarus, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a sliding clasp fastener having two rows of fastener members carried by respective continuous carrying strips, each fastener member comprising a neck and a coupling head, and recesses provided between fastener members of each row for receiving the coupling heads of fastener members of the other row. In sliding clasp fasteners of this kind, the row of fastener members of one slide fastener half is the mirror image of the row of fastener members of the other slide fastener half.When the two rows of fastener members are coupled, the recesses between the necks of the fastener members, together with the coupling heads which engage in the recesses, provide the secure interlocking which is required in order to enable the fastener to withstand the lateral stresses which occur in the plane of the fastener.

The term orthogonal locking shoulders, as used hereinafter, refers to locking shoulders which prevent the fastener members from becoming disengaged when stresses occur at right angles to the plane of the fastener while the rows of fastener members are coupled.

Although it has been proposed to provide fastener members with orthogonal locking shoulders in the form of grooves and ribs which constitute side faces of the fastener members, it is very difficult to produce locking shoulders like these in small sizes of sliding clasp fasteners such as used in the clothing industry. Moreover, such fastener members having orthogonal locking shoulders can only be produced by an injection moulding process and, because of the tolerances resulting from the shrinkage of the moulded material, the break-open strength of the fasteners is reduced even if they are of a heavy-weight type.

An object of the invention is to provide orthogonal locking shoulders on fastener members in a manner which will facilitate the production of small sizes of sliding clasp fasteners.

According to the present invention, a sliding clasp fastener has two rows of fastener members carried by respective continuous carrying strips, each fastener member comprising a neck and a coupling head, and recesses provided between fastener members of each row for receiving the coupling heads of fastener members of the other row, the fastener members being formed from two laminae of synthetic plastics material each formed with coupling head portions and are joined together in a staggered condition so that adjacent coupling head portions of the two laminae jointly provide orthogonal locking shoulders.

Preferably, each orthogonal locking shoulder terminates at each end in a crescent portion. The fastener is flexible when bending stresses occur in the plane of the fastener due to the orthogonal locking shoulders ending in a crescent portion which does not produce a stiffening effect at the bottom of the recesses for receiving the coupling heads. Holes or indentations may be provided in the carrying strips to increase flexibility. In order to make the sliding clasp fastener flexible for bending out of the plane of the fastener, at least some of the indentations may be weakening grooves between the fastener members. The two laminae may be formed from synthetic thermoplastics material and be fused together.

Each carrying strip may be provided with holes for the passage of a sewing needle when attaching the carrying strip to a garment or to a textile carrier tape by sewing.

If the carrying strips are to be attached to separate carrier tapes, the edge of each carrying strip remote from the fastener members may define a U-shaped groove to receive an edge of the carrier tape which is secured to surfaces of the groove. Alternatively, a textile carrier tape may have been secured to one of the two laminae by passing the carrier tape through an extension nozzle which forms the lamina.

At least one of the laminae may extend laterally to provide a carrier tape which is integral with the corresponding carrying strip and its fastener members. Alternatively, each carrying strip may be woven or knitted into a textile carrier tape.

One embodiment of the invention will now be described, by way of example on)y with reference to the single accompanying drawing which is a perspective view on a considerably enlarged scale of a portion of sliding clasp fastener which is partially unfastened.

Referring to the drawing, a sliding clasp fastener comprises two rows 1 of fastener members 2 carried by respective continuous carrying strips 3. Each fastener member 2 comprises a neck 4 and a coupling head 5 which is wider than the neck. Recesses 6 are provided between the fastener members 2 of each row to receive the coupling heads 5 of fastener members 2 of the other row. The fastener members 2 have orthogonal locking shoulders 7,8, and may be symmetrical with a bulbous form as shown in the drawing, or may be asymmetrical.

From the top part of the drawing, which shows the fastener in opened condition, it will be seen that the fastener members 2 are formed from two laminae 9,10 of synthetic plastics material which are each formed with portions of the coupling heads 5 and are staggered in the direction of the longitudinal axis of the sliding clasp fastener so that adjacent coupling head portions of the two Iaminae form orthogonal locking shoulders 7,8. Both pairs of laminae 9,10 are then joined together in the staggered position illustrated. Whilst various methods may be used for joining the laminae together, it is preferred to manufacture the laminae from a synthetic thermoplastics material and to fuse the abutting surfaces of the laminae using a suitable welding technique to produce a permanent integral structure.Each lamina 9,10 is preferably a continuous strip of the synthetic plastics material having a profiled edge defining the coupling head portions and formed by a stamping process. Whilst the shape of the orthogonal locking shoulders 7 is clearly seen from the drawing, the inverse orthogonal locking shoulders 8 face in the opposite direction as indicated by arrow 11 on the right-hand side of the drawing. It will be seen from the top right-hand corner of the drawing that each of the orthogonal locking shoulders 7,8 is generally of a sickle shape which is defined by the staggered edges of the two coupling head portions and terminates in crescent portions 12,13 that taper off to zero. In this manner the fastener is flexible when bending stresses occur in the plane of the fastener as the crescent portions do not produce a stiffening effect at the bottoms of the recesses 6.

The carrying strips 3 are each provided with transverse weakening grooves 14 between the fastener members 2 to increase flexibility, and also define guide edges 15 for a slider of which the general outline is indicated by dash-and-dot line 16. The grooves 14 may be replaced or supplemented by other holes or indentations to achieve a specific degree of flexibility in the carrying strips 3.

Each carrying strip 3 is attached to a respective carrier tape 17 of textile material.

For this purpose each carrying strip 3 is provided, in the edge remote from the fastener members 2, with a U-shaped groove 18 accommodating an edge of the carrier tape 17 which is secured to the carrying strip 3 in any suitable manner such as by bonding using an adhesive or by fusing the carrying strip 3 to the carrier tape 17. The U-shaped groove 18 may also be used for attaching a carrier tape made of synthetic plastics or thermoplastics material in a similar manner, and the carrier tape may have a selected surface texture or coating if required.

The carrying strips 3 may be provided with holes or indentations, such as those indicated by reference 19, which serve for the passage of a sewing needle when a carrying strip 3 is attached to a garment or to a textile carrier tape by sewing.

The carrier tapes 17 may alternatively be formed integrally with the carrying strips 3. In one example, a textile carrier tape may be led through the nozzle of a plastics extruder whilst one of the laminac 9 or 10 is being formed whereby one edge of the textile carrier tape will be welded or fused or otherwise bonded to the adjacent edge of the lamina. In another example, one or both of the laminae 9,10, is formed sufficiently wide that an integral portion will be left on the side of the carrying strip 3 remote from the fastener members 2 and will serve as the carrier tape; this is a particularly economical construction as the step of securing a separate carrier tape to the carrying strip is avoided.

The joined laminae 9,10 may alternatively merely define the fastener members 2 and the carrying strip 3, and be woven or knitted into the edge of a textile carrier tape. An advantage achieved by the pre- sent invention is that small sizes of sliding clasp fasteners can be produced. Even if the fastener members have a thickness of only 1 mm or less, it is possible to stagger the two laminae 9 and 10 to form the orthogonal locking shoulders 7 and 8. The orthogonal locking shoulders themselves ensure that the fastener can withstand considerable stresses at right angles to the plane of the fastener without the slide fastener's flexibility being impaired, especially since the carrying strips 3 can be thinner than the fastener members 2.A particular advantage is that rows of fastener members having orthogonal locking shoulders can be produced in a simple process such as that described in our U.K. Specification No.

1494985.

WHAT WE CLAIM IS: 1. A sliding clasp fastener having two rows of fastener members carried by respective continuous carrying strips, each fastener member comprising a neck and a coupling head, and recesses provided between fastener members of each row for receiving the coupling heads of fastener members of the other row, the fastener members being formed from two laminae of synthetic plastics material which are each formed with coupling head portions and are joined togather in a staggered condition so that adjacent coupling head portions of the two laminae jointly provide orthogonal locking shoulders.

2. A sliding clasp fastener, according to Claim 1, wherein each orthogonal locking shoulder terminates at each end in a crescent portion.

3. A sliding clasp fastener according to Claim 1 or 2 wherein holes or indentations are provided in the carrying strips to increase flexibility.

4. A sliding clasp fastener, according to Claim 3, wherein at least some of the indentations are weakening grooves between the fastener members.

5. A sliding clasp fastener, according to any preceding claim, wherein the two laminae are formed from synthetic thermoplastics material and are fused together 6. A sliding clasp fastener, according to any preceding claim, wherein each carrying strip has holes for the passage of a sewing needle when attaching the carrying strip to a garment or a textile carrier tape by sewing.

7. A sliding clasp fastener, according to any preceding claim, wherein each carrying strip defines a U-shaped groove in its edge remote from the fastener members to receive an edge of a carrier tape which is secured to surfaces of the groove.

8. A sliding clasp fastener, according to any of Claims 1 to 5, wherein a textile carrier tape has been secured to one of the two laminae by passing the carrier tape through an extrusion nozzle which forms the lamina.

9. A sliding clasp fastener, according to any of Claims 1 to 5, wherein at least one of the laminae extends laterally to provide a carrier tape which is integral with the corresponding carrying strip and its fastener members.

10. A sliding clasp fastener, according to any of Claims 1 to 5, wherein each carrying strip is woven or knitted into a textile carrier tape.

11. A sliding clasp fastener substantially as described herein with reference to and as shown in the accompanying drawing

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the carrying strip 3, and be woven or knitted into the edge of a textile carrier tape. An advantage achieved by the pre- sent invention is that small sizes of sliding clasp fasteners can be produced. Even if the fastener members have a thickness of only 1 mm or less, it is possible to stagger the two laminae 9 and 10 to form the orthogonal locking shoulders 7 and 8. The orthogonal locking shoulders themselves ensure that the fastener can withstand considerable stresses at right angles to the plane of the fastener without the slide fastener's flexibility being impaired, especially since the carrying strips 3 can be thinner than the fastener members 2.A particular advantage is that rows of fastener members having orthogonal locking shoulders can be produced in a simple process such as that described in our U.K. Specification No. 1494985. WHAT WE CLAIM IS:

1. A sliding clasp fastener having two rows of fastener members carried by respective continuous carrying strips, each fastener member comprising a neck and a coupling head, and recesses provided between fastener members of each row for receiving the coupling heads of fastener members of the other row, the fastener members being formed from two laminae of synthetic plastics material which are each formed with coupling head portions and are joined togather in a staggered condition so that adjacent coupling head portions of the two laminae jointly provide orthogonal locking shoulders.

5. A sliding clasp fastener, according to any preceding claim, wherein the two laminae are formed from synthetic thermoplastics material and are fused together

6. A sliding clasp fastener, according to any preceding claim, wherein each carrying strip has holes for the passage of a sewing needle when attaching the carrying strip to a garment or a textile carrier tape by sewing.