GB2265941A - Sliding clasp fastener: end stop application - Google Patents

Abstract

A sliding clasp fastener chain (2) is subdivided into chain lengths by gaps (5) and end stop members (6) disposed in the gap zones. As the sliding clasp fastener chain is advanced, a buffer finger (8) falls into each successive gap (5) and abuts on a final stop member (6) stopping the chain. A drift pin (9) then enters between the two sliding clasp fastener halves, behind the buffer finger (8) and urges the two halves apart. The sliding clasp fastener chain (2) is then retracted in the opposite direction to its advance, until the starts of the rows (4) of interlocking members immediately behind the gap (5) lie against a stop (11). The parted sliding clasp fastener halves are then clamped on the guide table (7). The start members of the two rows (4) of interlocking members are then urged out towards their stringer tapes (3), parallel to the surfaces of the stringer tapes (3), with the aid of cross-slides. Finally. the outwardly urged start members (12) are welded to introduced additional material (14) forming top end stops. <IMAGE>

Description

2265941 SLIDING CLASP FASTENER WORKING PROCESS This invention relates to a

working process for the application of an initial stop member to a sliding clasp fastener chain comprising two sliding clasp fastener chain halves each having a stringer tape and a row of interlocking members attached thereto, the sliding clasp fastener chain being subdivided into chain lengths corresponding to the finished sliding clasp fasteners by gaps and final stop members disposed in the gap zones. A device for carrying out the said process is a further independent object of the invention.

A process of the type initally defined is disclosed in the publication DE 37 12 402. In this process, the starts of the rows of interlocking members encounter a buffer to position the sliding clasp fastener for the application of a is metallic initial stop member. The two sliding clasp fastener halves can be urged apart by means of a drift pin to allow the introduction of additional material to form the initial stop member. The device for carrying out the said process has a clamp to immobilise the sliding clasp fastener chain during the application of the inital stop member. In this process, the sliding clasp fastener chain abutting the buffer continues to advance, bringing with it a tool block into an initial stop member application position, against the action of gravity or a return spring. This has the disadvantage that the sliding clasp fastener chain comes under heavy mechanical loading from the force opposing its continued advance. The force opposing the advance of the chain has the more particularly serious effect of limiting the precision with which the initial stop member can be positioned. A further disadvantage of this process consists in that the applied initial stop members are attached relatively insecurely and can be displaced relatively easily by stronger mechanical loading. It is known, in a process disclosed in DE 38 25 713, for the drawing of the sliding clasp fastener sliders on to the successive chain lengths in a lengthy sliding clasp fastener chain, for a buffer to enter a gap in the sliding clasp fastener chain and abut on the preceding final stop member. The gap is next widened by means of a drift pin, to facilitate the insertion of a sliding clasp fastener slider. A sensor confirms the presence of the sliding clasp fastener slider and effects the immobilisation of the sliding clasp fastener chain with the aid of a clamp. There then ensues a series of forward and reverse movements of the sliding clasp fastener chain, whereby the sliding clasp fastener slider is slid onto the sliding clasp fastener chain. This process has the disadvantages that it involves relatively numerous operations and the associated devices contain relatively numerous components, including various sensors for example. Consequently, the process is complicated and the device occupies a relatively large space.

A basic object of the invention is to devise a process of the type initially described such that the initial stop members are both positioned exactly and functionally reliably and attached relatively securely, whilst the number of operations is minimised and the process is made-as.simple as possible. The further object of the invention is to provide a device for carrying out the process of the invention.

According to a first aspect of the present invention there is provided a working process for the application of an initial stop member to a sliding clasp fastener chain comprising two sliding clasp fastener chain halves each having a stringer tape and a row of interlocking members attached thereto, the sliding clasp fastener chain being subdivided into chain lengths corresponding to the finished sliding clasp fasteners by gaps and final stop members disposed in the gap zones, whereby as the sliding clasp fastener chain is advanced over a guide table a buffer finger falls into each successive gap and abuts on the preceding final stop member, whereby the sliding clasp fastener chain is then halted, a drift pin is inserted between the two sliding clasp fastener halves, behind the buffer finger in the direction of advance of the sliding clasp fastener chain, and the two halves are urged apart for the introduction of additional material, whereby the sliding clasp fastener chain is then retracted in the opposite direction to the advance of the sliding clasp fastener chain, until the starts of the rows of interlocking members immediately behind the gap lie against a stop, whereupon the sliding clasp fastener halves, parted by the drift pin, are clamped on the guide table by clamping means in the vicinity of the starts of the rows of interlocking members, whereby the start members of the two rows of interlocking members are urged out towards their stringer tapes, parallel to the surfaces of the stringer tapes, with the aid of cross-slides, and finally whereby the outwardly urged start members are welded to the introduced additional material with the aid of a welding tool.

The rows of interlocking members and the additional material consist of a synthetic thermoplastic material, preferably in a monofilament form.

The advantages accuring from the process of the invention are to be seen substantially in that the initial stop members can be positioned very exactly, so that the proportion of faulty sliding clasp fasteners produced can be reduced. It is also advantageous in that the operations associated with the process are less complicated, so that the process is relatively easy to control. No costly controlling and regulating devices are required. Furthermore, the process of the invention facilitates a relatively speedy application of the initial stop members, so that the process contributes to rapid and low-cost sliding clasp fastener production.

There are numerous possibilities for further modifications of the working process in detail. Thus, a sensor set up behind the buffer finger in the direction of advance of the sliding clasp fastener chain can detect the passage of a sliding clasp fastener slider positioned on a length of the chain and ensure that the speed of advance is reduced before the buffer finger falls into the advancing gap.

In a preferred embodiment of the invention, the process is so organised that the buffer finger abutting on the final stop member is entrained by the still advancing sliding fastener chain until it encounters a further stop whereby the advance of the sliding clasp fastener chain is arrested. In the simplest case, the drift pin is driven into the gap occupied by the buffer finger. It is within the scope of the invention to drive a second drift pin into the opened section of the length of sliding clasp fastener chain adjacent to the gap containing the buffer finger between the two sliding clasp fastener halves. The parted halves of the sliding clasp fastener chain are preferably clamped by means of a clamping plate which descends on to the guide table from above. In a preferred embodiment of the invention, the sliding clasp fastener chain is transported over the guide table with its front face presented to the top face thereof, the additional material being fed in from below to the parted start members of the parted start members of the two rows of interlocking members, through two guide channels disposed under the guide table. The additional material is preferably fed through the guide channels in monofilament form and cut into the lengths required to make the initial stop members by cutters at the ends of the guide channels, underneath the parted start members. The cutters preferably operate from below at right angles to both the sliding clasp fastener chain surface and the guide channels, and also act as backing tools when the sections of additional material are welded in. The welding of the parted start members to the additional material can be effected in various ways, for example by a thermal welding process. In one preferred embodiment of the invention, the process is so organised that the parted start members are welded ultrasonically to the additional material with the aid of a sonotrode as welding tool, in which case the sonotrode is presented to the sliding clasp fastener chain from over the guide table. In a preferred embodiment, the initial stop member is formed by two rectangular segments, one at the start of each row of interlocking members, having a height at right angles to the stringer tape surface of about 1.3 mm, a length in the direction of the sliding clasp fastener chain of about 3.5 mm and a breadth of about 2.45 mm.

According to a second aspect of the present invention there is provided a device for carrying out the process of the first aspect, a guide table for the sliding clasp fastener chain, an attachment for transporting the sliding clasp fastener chain, a buffer finger, a drift pin, an abutment for the starts of the rows of interlocking members, a clamp for the sliding clasp fastener chain and guides for the additional material, the buffer finger which falls into a gap in the sliding clasp fastener chain effecting the arrest of the transport motion of the sliding clasp fastener chain, the buffer finger being movable in the opposite direction to the advance of the sliding clasp fastener chain, the abutment being so adapted that retraction of the sliding clasp fastener chain by the buffer finger brings the starts of the interlocking member rows back to the abutment, 5 cross-slides being provided to urge outwards the start members of the two rows of interlocking elements, and a welding tool being provided for the parted start members. The device of the invention has the oustanding advantages of having a relative small number of easily deployed components and therefore being relatively compact and moreover easy to operate.

It is within the scope of the invention to fit the device with a sensor, set up behind the buffer finger in the direction of advance, to detect the appearance of a sliding clasp fastener slider. A second abutment for the buffer finger can be provided, behind the buffer finger in the direction of advance, and in the simplest case the sensor can be adapted as the second abutment. The drift pin is so positioned, in the simplest case, that it can be driven into the gap in which the buffer finger is disposed. A preferred emobidment of the invention is characterised in that a second drift pin is provided, at a distance from the first drift pin such that it can be driven into the opened segment of the sliding clasp fastener chain. The clamping means are preferably adapted as a clamping plate, whilst in the simplest case the drift pins are mounted on the underside of the clamping plate. In one embodiment of the device of outstanding simplicity and functional reliability, a tooling component is disposed under the guide table, carrying the abutment for the starts of the rows of interlocking members, the two cross-slides and the guides for the additional material, in the form of guide channels. The tooling component preferably carries the cutters for sectioning the additional material, disposed at the ends of the guide channels under the parted start members. In a preferred embodiment of the invention, the cutters are disposed in pits at rights angles to both the sliding clasp fastener chain surface and the two guide channels and are adapted as backing tools for the welding of the sectioned additional material. The guide channels are preferably square in cross-section, with side lengths of 1.2 to 1.8 mm. In a preferred embodiment of the device, the welding tool is sonotrode mounted over the guide table. one embodiment of the invention will now be described in greater detail, by way of example with reference to the accompanying schematic drawings, in which:20 Figure 1 is the side elevation of a device of the invention for carrying out the process of the invention, showing an initial functional position; Figure 2 shows the device of Figure 1 in more detail and in another functional position; 25 Figure 3 is a plan view of Figure 2 in a third functional position, looking in the direction of the arrow A; Figure 4 is a view of the area B of Figure 3, on a much larger scale and showing more detail; 9 - Figure 5 corresponds to Figure 4 but shows a fourth functional position; Figure 6 is a view from the direction of the arrow C in Figure 3 of the device of Figure 3 on a larger scale and in a fifth functional position; Figure 7 is a view of the area D of Figure 6, on a much larger scale than Figure 6 and showing more detail; Figure 8 shows the device of Figure 7 in another functional position; and Figure 9 is a plan view of a sliding clasp fastener chain after applying an initial stop member designed in accordance with the invention.

The device shown in the drawings is designed to carry out a working process for the application of an initial stop member 1 to a sliding clasp fastener chain 2 comprising two sliding clasp fastener chain halves each having a stringer tape 3 and a row 4 of interlocking members attached thereto. The sliding clasp fastener chain 2 is subdivided into chain lengths corresponding to the finished sliding clasp fasteners by gaps 5 and final stop members 6 disposed in the gap zones.

The basic structure of the device for carrying out the working process incorporates a guide table 7 for the sliding clasp fastener chain 2, an attachment not shown for transporting the sliding clasp fastener chain 2, a buffer finger 8, a drift pin 9, an abutment 11 for the starts of the rows 4 of interlocking members, a clamp 10 for the sliding clasp fastener chain 2 and guides 19 for the additional material 14.

A comparison of Figures 1 and 2 will show that as the sliding clasp fastener chain 2 advances over the guide table 7, the buffer finger 8 falls into each successive gap 5 and abuts on the preceding final stop member 6. In the preferred embodiment shown, the process is so organised that a sensor 16 is set up behind the buffer finger 8 to detect the passage of a sliding clasp fastener slider 17 positioned on a length of the chain and ensure that the speed of advance is reduced before the buffer finger 8 falls into the advancing gap 5. In one preferred embodiment of the invention, the process is so devised that the buffer finger 8 abutting on the final stop member 6 is entrained by the still advancing sliding clasp fastener chain 2 until it encounters a further stop whereby the advance of the sliding clasp fastener chain 2 is arrested. In a preferred embodiment of the invention, the sensor 16 is adapted as the second abutment for the buffer finger 8.

In the process of the invention, a drift pin 9 is next driven between the two sliding clasp fastener halves, into the gap left behind the buffer finger 8 in the direction of advance of the sliding clasp fastener chain 2, whilst the sliding clasp fastener 2 is immobilised, and the two halves are urged apart for the introduction of additional material 14. Figure 2, which shows a preferred embodiment of the invention, shows that the drift pin 9 is driven into the gap 5 in which the buffer finger 8 is disposed. Figure 2 also shows that in this preferred embodiment a second drift pin 18 is provided, at a distance from the first drift pin 9 such that it can be driven into the opened segment of the sliding clasp fastener chain adjacent to the gap 5 between the two halves containing the buffer finger 8.

In continuation of the process of the invention, the sliding clasp fastener chain is retracted in the opposi-te direction to the advance of the sliding clasp fastener chain 2, with the buffer finger 8 abutting on the final stop member 6, until the starts of the rows 4 of interlocking members immediately behind the gap 5 lie against a stop 11. This can be clearly seen from a comparison of Figures 2, 3 and 4. Thereupon, the sliding clasp fastener halves, parted by the drift pins 9, 18, are clamped on the guide table 7 by clamping means 10 in the zone of the starts of the rows 4 of interlocking members. The clamping means 10 are preferably adapted as a clamping plate lowered onto the guide table 7 from above. In the preferred embodiment of the invention shown, the drift pins 9, 18 are mounted on the underside of the clamping plate. As can be seen by comparing Figure 4 and 5, in the next step of the process of the invention, the start members 12 of the two rows 4 of interlocking members are urged out towards their stringer tapes 3, parallel to the stringer tapes 3, with the aid of cross-slides 13. Finally, the outwardly urged start members 12 are welded to the introduced additional material 14, with the aid of a welding tool 15, to form the initial stop member 1. This is clearly seen on comparing Figures 6, 7 and 8.

In the embodiment of the working process shown, the sliding clasp fastener chain 2 is transported over the guide table 7 with its front face presented to the top face of the guide table. This is indicated in Figure 1. As Figure 2 shows, the additional material 14 is preferably fed in from below to the parted start members 12 of the two rows 4 of interlocking members, through two guide channels 19 disposed under the guide table. In the preferred embodiment of the invention shown in Figures 2 and 3, a tooling component 21 is disposed under the guide table 7, carrying the abutment 11 for the starts of the rows 4 of interlocking members, the two cross-slides 13 and the guides 19 for the additional material 14. The additional material 14 introduced through the guide channels 19 in monofilament form for example is preferably cut into the lengths required to make the initial stop members 1 by cutters 20 at the ends of the guide channels 19, underneath the parted start members 12. As shown in Figures 2 and 6, the cutters 20 are preferably disposed in pits 22 in the tooling component 21, so that they operate from below at right angles to both the sliding clasp fastener chain surface and the guide channels 19 and are also adapted as backing tools for the welding of the sectioned additional material 14. The guide channels 19, which are shown in Figures 2, 4 and 5, are preferably square in cross- section, with side lengths of 1.2 to 1.8 mm.

In a preferred embodiment of the invention, the process is so organised that the parted start members 12 are welded ultrasonically to the additional material 14 with the aid of a sonotrode as the welding tool 15 (Figures 6, 7 and 8), in which case the sonotrode is presented to the sliding clasp fastener chain 2 from over the guide table 7.

In the process of the invention, as shown in Figure 9, the initial stop member 1 is formed by two rectangular segments, one at the start of each row 4 of interlocking members, having a height at right angles to the stringer tape surface of about 1.3 mm, a length in the direction of the sliding clasp fastener chain 2 of about 3.5 mm and a breadth of about 2.45 mm.

Claims (27)

1. A working process for the application of an initial stop member to a sliding clasp fastener chain comprising two sliding clasp fastener chain halves each having a stringer tape and a row of interlocking members attached thereto, the sliding clasp fastener chain being subdivided into chain lengths corresponding to the finished sliding clasp fasteners by gaps and final stop members disposed in the gap zones, whereby as the sliding clasp fastener chain is advanced over a guide table a buffer finger falls into each successive gap and abuts on the preceding final stop member, whereby the sliding clasp fastener chain is then halted, a drift pin is inserted between the two sliding clasp fastener halves, behind the buffer finger in the direction of advance of the sliding clasp fastener chain, and the two halves are urged apart for the introduction of additional material, whereby the sliding clasp fastener chain is then retracted in the opposite direction to the advance of the sliding clasp fastener chain, until the starts of the rows of interlocking members immediately behind the gap lie against a stop, whereupon the sliding clasp fastener halves, parted by the drift pin, are clamped on the guide table by clamping means in the vicinity of the starts of the rows of interlocking members, whereby the start members of the two rows of - is interlocking members are urged out towards their stringer tapes, parallel to the surfaces of the stringer tapes, with the aid of cross-slides, and finally whereby the outwardly urged start members are welded to the introduced additional material with the aid of a welding tool.

2. A process as in Claim 1, whereby a sensor set up behind the buffer finger in the direction of advance of the sliding clasp fastener chain detects the passage of a sliding clasp fastener slider on a length of the chain and ensures that the speed of advance is reduced before the buffer finger falls into the advancing gap.

3. A process as in Claim 1 or 2, whereby the buffer finger abutting on the final stop member is entrained by the still advancing sliding clasp fastener chain until it encounters a further stop whereby the advance of the sliding clasp fastener chain is arrested.

4. A process as in any of Claims 1 to 3, whereby the drift pin is driven into the gap occupied by the buffer finger.

5. A process as in any of Claims 1 to 4, whereby a second drift pin is driven into the opened section of the length of sliding clasp fastener chain adjacent to the gap occupied by the buffer finger, between the two sliding clasp fastener halves.

6. A process as in any of Claims 1 to 5. whereby the parted halves of the sliding clasp fastener chain are clamped by means of a clamping plate which descends on the guide table from above.

7. A process as in any of Claims 1 to 6, whereby the sliding clasp fastener chain is transported over the guide table with its front face presented to the top face thereof, the additional material being fed in from below to the parted start members of the two rows of interlocking members, through to guide channels disposed under the guide table.

8. A process as in Claim 7, whereby the additional material is fed through the guide channels in monofilament form and cut into lengths required to make the initial stop members by cutters at the ends of the guide channels, underneath the parted start members.

9. A process as in Claim 8, whereby the cutters operate from below at right angles to both the sliding clasp fastener chain surface and the guide channels, and also act as backing tools when the sections of additional material are welded in.

10. A process as in any of Claims 1 to 9, whereby the parted start members are welded ultrasonically to the additional material with the aid of a sonotrode as welding tool, in which case the sonotrode is presented to the sliding clasp fastener chain from over the guide table.

11. A process as in any of Claims 1 to 10, whereby the initial stop member is formed by two rectangular segments, one at the start of each row of interlocking members, having a height at right angles to the stringer tape surface of about 1.3 mm, a length in the direction of the sliding clasp fastener chain of about 3.5 mm and a breadth of about 2.45 mm.

12. A process as claimed in any preceding Claim, wherein the rows of interlocking members and the additional material consist of a synthetic thermoplastic material, preferably in a monofilament form.

13. A process as claimed in Claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.

14. A device for carrying out the process as in any of Claims 1 to 13, comprising a guide table for the sliding clasp fastener chain, an attachment for transporting the sliding clasp fastener chain, a buffer finger, a drift pin, an abutment for the starts of the rows of interlocking members, a clamp for the sliding clasp fastener chain and guides for the additional material, the buffer finger which falls into a gap in the sliding clasp fastener chain effecting the arrest of the transport motion of the sliding clasp fastener chain, the buffer finger being movable in the opposite direction to the advance of the sliding clasp fastener chain, the abutment being so adapted that retraction of the sliding clasp fastener chain by the buffer finger brings the starts of the interlocking member rows back to the abutment, cross-slides being provided to urge outwards the start members of the two rows of interlocking elements, and a welding tool being provided for the parted start members.

15. A device as in Claim 14, in which a sensor is set up behind the buffer finger in the direction of advance, to detect the appearance of a sliding clasp fastener slider.

16. A device as in Claim 14 or 15, in which a second abutment is provided for the buffer finger, behind the buffer finger in the direction of advance.

17. A device as in Claim 16, in which the sensor is adapted as the second abutment.

18. A device as in any of Claims 14 to 17, in which the drift pin is so positioned that it can be driven into the gap in which the buffer finger is disposed.

19. A device as in any of Claims 14 to 18, in which a second drift pin is provided, at a distance from the first drift pin such that it can be driven into the opened segment of the sliding clasp fastener chain.

20. A device as in any of Claims 14 to 19, in which the clamping means are adapted as a clamping plate. 20

21. A device as in Claim 20, in which the drift pins are mounted on the underside of the clamping plate.

22. A device as in any of Claims 14 to 21, in which a tooling component is disposed under the guide table, carrying the abutment for the starts of the rows of interlocking members, the two cross-slides and the guides for the additional material, in the form of two guide channels.

23. A device as in Claim 22, in which the tooling component carries the cutters for sectioning the additional material, disposed at the ends of the guide channels under the parted start members.

24. A device as in Claim 23, in which the cutters are disposed in pits at right angles to both the sliding clasp fastener surface and the two guide channels and are adapted as backing tools for the welding of the sectioned additional material.

25. A device as in any of Claims 22 to 24, in which the guide channels are square in cross-section, with side lengths of 1.2 to 1.8 mm.

26. A device as in any of Claims 14 to 25, in which the welding tool is a sonotrode mounted over the guide table.

27. A device as claimed in Claim 14, substantially as hereinbefore described with reference to the accompanying drawings.