GB2179968A

GB2179968A - Transport means for fastener stringers

Info

Publication number: GB2179968A
Application number: GB08619307A
Authority: GB
Inventors: Helmut Heimberger
Original assignee: Opti Patent Forschungs und Fabrikations AG
Current assignee: Opti Patent Forschungs und Fabrikations AG
Priority date: 1985-09-06
Filing date: 1986-08-07
Publication date: 1987-03-18
Also published as: SU1577683A3; FR2586910A1; GB2179968B; PT83294A; DE3531812C1; FI863525A; PT83294B; JPS6284705A; GB8619307D0; FI85797C; FI863525A0; FR2586910B1; FI85797B

Abstract

A feed arrangement is for two stringer tapes with rows of interlocked members wherein the slide fastener chain can be moved forward in steps so that completion operations can be performed during pauses in the movement. Drive is via a stepping motor or a direct current servomotor, to which the data for the travel distance and positioning can be supplied via a microprocessor. The positioning drive has a driving sprocket acting on the length of coupled stringer tapes, the teeth of which engage into the interstices between adjacent interlocked members and its tooth flanks lie against at least one side of the adjacent interlocked members. The travel distance and the positioning of the completion areas are determined by the angle of rotation of the driving sprocket. <IMAGE>

Description

SPECIFICATION Transport means for fastener stringers This invention relates to an equipmentto move forward and position a length of two stringertapers with rows of interlocking members in the coupled condition particularly where the interlocking members are made from plastics monofilament, in the course ofthe performance ofcompletion operations in which the length can be moved forward in steps of a specified distance and the completion operations can be performed in positioned completion areas by means of completion tools, during pauses in the movement, with a drive operating on the length according to specified positioning data. It is to be understoodthatthe interlocking members each has an interlocking head, two sides and connection sections atthe rear.The union ofthe rows of interlocking membersto the supportstrips can be produced by weaving in or sewing in and has suitable binding-in orattachmentthreads that grip overthe sides more or less completely. "Completion operations" describes processes that are preformed on the length by the tools of appropriate machines and serve to produce an individual sliding claspfastener. This may be the mounting of connecting members, of end stops, cutting to length, or the mounting ofcompo- nents of a slider to separate the coupled interlocking members.The corresponding operations are not only co-ordinated with the lengths of sliding clasp fastenersto be manufactured, they also require special positioning with reference to individual interlocking members within the bounds ofthe required degree of movement.

With known equipment the forward movement of the length of coupled stringertapes takes place by means of rollers, driven correspondingly in steps, which do not positively engage the length but move the length by frictional contact. The positioning of the length is merely monitored, by an auxiliary device consisting of a sprocket, the teeth of which engage between the adjacent interlocking members, and a cog-wheel seated on the shaft ofthe sensor sprocket, which acts on a switch via a lever bar. The design is so arranged thatthe tools for the completion operations can only operate if the switch is closed -which in turn is only the case ifthe positioning is correct. Forthis reason the auxiliary device is located directly before the completion area.The known means do not work satisfactorily because relative motion caused by slip is possible between the rolls and the length, which is deleterious to the positioning and has to be put right by tedious hand correction. Also the known equip ment cannot be employed with lengths of differnt thicknesses and with plastics monofilaments of different thicknesses.

In other areas ofthe art, computer-controlled positioner drives are known with stepping motors or directcurrentservomotorsthatcan be numerically controlled and make it possible to convertelectroni- cally-specified variable quantities into path lengths and to position articles that are to be worked upon.

Hitherto such positioner drives have not contributed to further development of equipmentforthe production of sliding clasp fasteners, particularly because when rolls are used for the transport of the lengths of stringertapesthe above-described problems remain and the greater resolution potentiality of a computercontrolled positional drive cannot be utilised to good effect.

It is the object of the invention to provide equipment forthe manufacture of sliding clasp fasteners with a computer-controlled positional drive, and at the same time to improve it in such a way that a very accurate positioning ofthe length of coupled stringer tapes in the completion area is achieved, and slide fastener chains the slide fastener links ofwhich are constructed ofstringertapes of different thicknesses and plastics monofilament of different thicknesses can be processed in one and the same equipment without any difficulty.

According to the present invention, an equipment to move forward and position ion a length of two stringer tapes having rows of interlocking members in the coupled condition particularlywith interlocking mem bersformed from plastics monofilament, in the course ofthe performance of completion operations, in which the length is moved forward in steps of a specified length and the completion operations are performed in positioned completion areas ofthe length by means of completion tools, during pauses in the movement comprises a drive constructed as a positioning drive, with a stepping motor or a direct current servomotor to which the data forthe required movement and positioning ofthe coupled stringertapes can be supplied via a microprocessor the positioning drive having at least one driving sprocket, the teeth of which engage in the interstices between adjacent interlocking members with the tooth flanks lying against at least one side face of adjacent interlocking members the required movement and the positioning of completion areas being determined bythe angle of rotation ofthe driving sprocket. The invention makes use of the fact that rows of interlocking members on stringertapes have over a given length, according to the pitch oftheirspacing, a specified and defined number of interlocking members, and that consequentlythe drive sprocket that meshes with the interlocking members, transports a specified number of interlocking members according to the measure of the angle of rotation, thus acting similarly to a gear rack. Thus the length of coupled stringer tapes is pushed or drawn forward by the driving sprocket and is positioned at the sametime.All of this takes place very accurately, because the contact points on the sides ofthe interlocking members are accurately co-ordinatedwith thetooth flanks, and all forward movement and positioning tasks arecorresoponding lyco-ordinated i.e. computed. If plastics monofilament is used the interlocking members that have a different thickness, then the position of the contact points with the teeth ofthe sprocket does indeed alter, which is taken account of by the information, i.e., the input to the microprocessor. In other respects however, nothing in the equipment according to the invention is altered. Consequently lengths of coupled stringer tapes for different types of sliding clasp fastener, i.e. with plastics monofilament of different thicknesses, can be completed in one and the same equipment.It is readily understood that the computer is appropriately programmed.

Preferablythere is feedback of information and therebyfurther control ofthe positioning. In the simplest case a sensor is associated with the positioning drive that measures the actual angle of rotation traversed by the driving sprocket, and this measured value can betransmittedto thepositioning drive as a correction value, thereby providing rotation angle feedback. In addition there can be provided a sensor associated with the positioning drive that measures the actual distance traversed by the length of coupled stringertapes and this measured value can be transmitted to the positioning drive as a correction value.

In this respect distance travelled feedback, normal with computer-controlled positioning equipments, is employed to increase the accuracy by way of autocontrol ofthe equipment. The sensor can be constructed as a sprocket sensor and be adapted to the type of driving sprocket. However, a sensor can be associated with the positioner drive that measures the actual positioning in the completion area, and this measured value can be transmitted to the positioning drive asa correction value. Here positioner measure mentfeedbacktakes place forthe purpose of increasing accuracy. In this case the sensor is advisably constructed as an optical sensor. If rotation angle feedback is used, then the normal small tolerances in respect of angle of rotation usual in positioner drives can be maintained.On the other hand, the pitch ofthe interlocking members on the stringertapes and the angle of rotation must be adjusted to one another.

Should the pitch change for reasons of engineering tolerance then this can be determined by test from case to case and from time to time, and taken into account bya correction input to the positioning drive.

With distance travelled feedback and with positioner measurementfeedback automatic correction in this respecttakes place.

Within the scope ofthe invention, the shape of the driving sprocket is basically optional. As sliding clasp fasteners in which the interlocking members are increasingly made from plastics monofilament nor- mally have binding-in or attachmentthreads that rest on top ofthe slides ofthe interlocking members and coverthem over more or less completely, a form of construction of the invention preferred in this instance is characterised in thatthe driving sprocket orthe sensor sprocket possess tooth sides converging like knife blades towards the tips of the teeth and which can be pressed through any possible covering ofthe slide fastener links by textile binding-in or attachment threads.Of course the pressure of the driving sprocket on the sides of the interlocking members can be brought about either by providing the driving sprocket itself with an appropriate pressure device acting towards the sides of the interlocking members or in the reverse way by pressing the support ofthe slide fastener chain in the neighbourhood of the driving sprocket against the driving sprocket, or both methods can be combined. It is further obvious that the driving sprocket is located as closely as possible before the completion area in orderto minimise errors caused by spacing.It also contributes to the minimisation of errors if the positioning drive has a separate drive sprocket and sensor sprocketfor each stringer tape which are located onthesamedriving shaft and have teeth that are displaced by half an interlocking member spacing pitch relatively to one another.

According to a preferred form of construction of the invention the depth of engagement of the teeth into the interstices between adjacent fastener links is adjustable. Then it is possible so to arrange the design thatthe positioning is adjustable by changing the depth of engagement oftheteeth. The computercontrolled positioner drive can also be arranged for a special process for movement control when automatic completion operations are performed on a slide fastener chain, as is important in combination with the above-described procedures.This known process is characterised in that the actual number of interlocking members on a required length of coupled stringer tapes entering the equipment is measured, thatthe quotient of the actual number of interlocking members and the associated length of sliding clasp fastener is then evaluated by computer, and that by comparisons of this quotient with the numerical value of a specified length of sliding clasp fastener, a required number of control steps is determined by the computer, according to the value ofwhich movement control forthe completion operations is performed.

One embodiment ofthe invention will now be described in detail with reference to the accompanying drawings, in which Figure lisa diagrammatic representation of equipment according to the invention, with rotational angle feedback; Figure 2 is a perspective view of a portion of an equipment according to the invention; and Figure3showsto an enlarged scale,the conditions when a tooth ofthe driving sprocket engages into the intertices between two adjacent interlocking members.

The equipment represented in the Figures, serves two moveforward and to position a continuous length of two stringer tapes 3 each having a row of interlocking members 2 of plastics monofilament and with the rows of interlocking members in the coupled condi tion, in the course of performance of completion operations. The continuous length 1 is moved forward in steps of a specified length. The length W is determined, for example, by the length ofthe slide fasteners to be manufactured and bythe location along the length ofthe completion areas K. During pauses in the movement, the completion operations are performed atthe required positioned K by means of completion tools position at the point indicated at 4.

A drive 5 operates on the continuous length 1 according to prescribed, predetermined positioning date. The positioning data indicates at what pointthe particular completion operation required at the time, for example the provision of end pieces or stop members, isto be performed.

The drive is constructed as a positioning drive 5. It operates with a stepping motor or a direct current servomotor. In any case the date forthe length of movement and its positioning can be supplied via a microprocessor 7. The positioning drive 5 has a driving sprocket 8 acting on the continuous length 1, connected to the shaft ofthe positioning drive5 by a toothed belt 6. Figure 3 shows that the teeth 9 ofthe driving sprocket 8 engage into the interstices 10 between adjacent interlocking members 2 and that the tooth flanks 11 act upon the side faces 12 ofthe adjacent interlocking members 2 at at least one contact point 13. The design is so arranged thatthe length of movement W is determined by the angle of rotation 14 of driving sprocket 8. This applies also to the positioning. The start and stop positions ofthe driving sprocket 8 are of course taken into account. In the form of construction shown in Figure 1, a sensor 15 is associated with positioning drive 5, which measuresthe actual angle of rotation and the measured value can be supplied as a correctional value to positioning driveS via microprocessor 7. It can be seen from Figure3thatthedepth of engagement of the teeth 9 into the interstices 10 between adjacent interlocking members 2 is adjustable. Consequently the positioning ofthe completion areas K can also be adjusted by changing the depth of engagement of teeth 9.

Claims

1. An equipmentto move forward and position a length of two stringertapes having rows of interlocking members in the coupled condition, particularly with interlocking members formed from plastic monofilament, in the course ofthe performance of completion operations, in which the length is moved forward in steps of a specified length and the completion operations are performed in positioned completion areas of the length by means of completion tools, during pauses in the movement comprising a drive constructed as a positioning drive, with a stepping motor or a direct current servomotorto which the data forthe required movement and positioning of the coupled stringertapescan be supplied via a microprocessorthe positioning drive having at least one driving sprocket, the teeth of which engage in the interstices between adjacent intelocking members with the tooth flanks lying against at least one side face of adjacent interlocking members the required movement and the positioning of completion areas being determined by the angle of rotation of the driving sprocket.

2. An equipment according to Claim 1, wherein a sensor is associated with the positioning drive that measures the actual angle of rotation traversed by the driving sprocket th is measured value being transmit tedto the positioning drive as a correction value.

3. An equipment according to any one of Claims 1 or2, wherein a sensor is associated with the positioning drive that measures the actual length of movement of the coupled stringertapes, this measured value being transmitted to the positioning drive as a correction value.

4. An equipment accordingto Claim 3,wherein the sensor is constructed as a sprocket sensor and is adapted to the type of driving sprocket employed.

5. An equipment according to Claim 1 or Claim 2, wherein a sensor is associated with the positioning drive that measures the actual positioning in the completion area this measured value being transmitted to the positioning drive as a correction value.

6. An equipment according to Claim 5, wherein the sensor is constructed as an optical sensor.

7. An equipment according to any one of Claims 1 to 6, wherein the driving sprocket or a sensor sprocket has tooth sides converging towardsthe tips of the teeth that can penetrate through any possible covering ofthe rows of interlocking members by textile binding-in orattachmentthreads.

8. An equipment according to any one of Claims 1 to 7, wherein the positioning drive has a separate drive sprocket and sensor sprocket for each stringertape of the length which are located on the same driving shaft and have teeth that are displaced by halfthe spacing pitch ofthe interlocking members.

9. An equipment according to any one of Claims 1 to 8, wherein the depth of engagement ofthe teeth into the interstices between interlocking members is adjustable.

10. An equipment according to Claim 9, wherein the positioning ofthe length is adjustable by changing the depth of engagement of the teeth between adjacent interlocking members.

11. An equipmentto move forward and position a length of two stringer tapes having rows of interlocking members in the coupled condition substantially as hereinbefore described with reference to the accompanying drawings.