CH621828A5 - Apparatus for cutting the linking cords of a line of zip fastener elements - Google Patents

Description

The invention relates to an apparatus for fixing zipper elements on fabric, for example the fabric of a garment, using which a line of zipper elements can be sewn directly onto the fabric of a garment without the intervention of the usual zipper tape.

The use of a row of U-shaped closure elements, not mounted on a strip of fabric, but only on a pair of cords serving to maintain the reciprocal spacing of the elements and to prevent them from tilting, is known by the US Patent No. 3,414,948.

It is also known to use, to fix these elements on fabric, a sewing machine provided with a mechanism synchronized with the coming and going of its needle and comprising a member which moves along a rectangular trajectory . This member has lugs which are inserted between two adjacent closure elements to move them in the direction of advance of the fabric, after which said path brings these lugs between the two following elements, to advance them, etc.

This mechanism, described in US Pat. No. 3,755,879, is eminently suited to the desired goal, but requires an interruption in the seam after fixing the required length of closure to the fabric, the cords then having to be cut by hand. The invention is intended to automate this process, and to make it possible to automatically cut the cords of a row of elements after fixing to the fabric of a predetermined length of closure, the separation then being carried out without interrupting the sewing operation. . This allows, among other things, to temporarily stop the supply of the machine with elements mounted on cords, after the section of the latter and without interrupting the seam when it is extended beyond the closure to better fix the latter to the fabric.

According to the invention, there is provided an apparatus suitable for use on machines performing the sewing of a continuous line of zipper elements on fabric and for separating the connecting cords from the line of closure elements after completion of the sewing operation. The apparatus comprises a blade driven in an alternating movement and suitable for being engaged between adjacent closing elements of the line, an articulated mechanism driven by the sewing machine to animate the blade in a back and forth movement. on a continuous path to feed the fabric and the slide elements step by step in the sewing machine, and a mechanism that can be actuated at will to deepen the path back and forth of the blade to separate the connecting cords.

The characteristics of the invention will appear from the following description of an apparatus according to the invention, this description being given by way of example and with reference to the appended drawings, in which:

fig. A is a view of a zipper element used in the apparatus;

fig. 1 is a perspective view of the apparatus according to the invention attached to a conventional sewing machine;

fig. 2 is a side view showing the adjacent parts of the sewing machine schematically and on the side opposite to that of FIG. 1, the lower part of the side of the device being partially torn off to show the knife guide means;

fig. 2a is a sectional view along line 2a-2a of FIG. 2;

fig. 3 is a top view of FIG. 2;

fig. 4 is a schematic front end view;

fig. 5 is a sectional view along line 5-5 of FIG. 3; fig. 6 is a sectional view along line 6-6 of FIG. 3; fig. 7 is a sectional view showing the cooperation of the feed and cut-off knife with a line of closing elements;

fig. 7a is a partial enlarged view of the front ends of the knife, as well as of the parts associated therewith in the position shown in FIG. 7;

fig. 8 is a sectional view similar to FIG. 7, but showing the feeding process at a later stage with the knife having fed one of the closing elements (blackened to be more easily recognized);

fig. 8a is a diagrammatic end view on a larger scale of the knife and of the parts which are associated with it in the position shown in FIG. 8;

fig. 9 is a view similar to that of FIGS. 7 and 8, but showing the needle fully inserted with the cutting rod placed to cause cutting of the line of closing elements;

fig. 9a is a diagrammatic enlarged view of the knife and of the parts associated therewith in the position shown in FIG. 9;

fig. 10 is a front end view of a variant provided for sewing side by side of lines of closure elements, this view being partly in section to show the relative position of the feed knife and the lines;

fig. 11 is a side view, partly in section, showing the apparatus of FIG. 10;

fig. 12 is a view showing lines of closure elements fixed to a single piece of fabric by modification of the apparatus shown in FIGS. 10 and 11;

fig. 13 is an enlarged sectional view of the product shown in FIG. 12, the fabric having been cut between the lines;

fig. 14 is a view which illustrates a subsequent step towards completion with respect to the step shown in FIG. 13 and where the

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fabric is folded to arrange the lines of closure elements on the inside of the fabric invisibly;

fig. 15 shows, in section, the closure of FIG. 14, with its lines cooperating with each other;

fig. 16 is a view of the fabric with the assembly of FIG. 15 showing the zipper slider and an end stop;

fig. 17 is a schematic diagram showing the system using the apparatus shown in Figs. 1 to 11, and fig. 18 is a block diagram showing the various stages of the process implemented in the system of FIG. 17.

Referring to the drawings, FIG. A shows a U-shaped zipper having a larger head H at its base, legs L and heels N. Notches O form indentations in the legs near the heels. This U-shaped element is made of plastic and, in the heels, are embedded cords M which reign over the entire length of the closure and which serve to immobilize the elements and to space them uniformly. As in the past, the separation of such closure lines is accomplished by simply cutting the cords M between adjacent elements, where desired.

As shown in fig. 1, the apparatus 10 is mounted on the shaft S of the presser foot of a conventional sewing machine having a needle shaft NB with a clamping flange C and a needle N which cooperates with the plate B of the sewing machine. FD feed dogs (fig. 2) cooperate with the fabric and move it into the machine from below.

The apparatus comprises a frame 12 having a foot with a vertical opening 14 suitable for receiving the shaft S of the presser foot to which the frame 12 is fixed by the fixing screw 16 provided in a tapped hole intersecting the opening 14 The front end of the frame comprises a pair of pressing shoes 18 and 20. The shoes are joined by a web 22 on which a spacing cam 24 depends (fig. 5). To stabilize the closing elements E as they move between the shoes 18 and 20 and are separated by the cam 24, the shoes can have flanges 26 and 28 extending inwards and which cooperate with the notches O (fig. A).

A supply arm 30 is disposed above the shoe 20 at the front of the frame, and said arm is mounted so as to be able to move in an alternating movement relative to the frame, with the possibility also of a slight movement vertical. The arm 30 rests against the frame 12 and is held against the latter by the retaining plate 31. The front end of the arm 30 is confined to a vertical movement limited by the stop finger 32, which is fixed by bolts , as shown on the left side of the frame 12 and which extends up above the shoe 18 to present its free end above the arm 30. In addition, the feed arm 30 is shaped to present a slot 34 adjacent to its rear end.

The slot 34 receives a T-shaped spacer 36 which is bolted by a bolt 38 to the frame. The spacer 36 limits the vertical movement of the rear of the arm, but allows an alternative horizontal movement of the arm against the frame (see section 2a).

As shown in fig. 2a, the frame 12 is pierced with drillings with progressively decreasing diameters 37, 37a, 37b from its upper end and moving away downward, the last bore 37b cutting the cutout for the rear end of the arm 30. The last drilling 37b receives a rod 39 which cooperates with the upper surface of the arm 30. The rod 39 has a head at its upper end and is biased downwards by a spring 39a disposed in the drilling 37a between the rod 39 and a screw adjustment 39b which is placed in an adjustable manner in the tapped bore 37. The pressure exerted on the supply arm by the rod 39 serves to dampen the movement of the arm 30 and also to slightly urge the front end of the arm 30 and counterbalancing the weight of said arm. This ensures that the knife 57 releases elements E when the knife moves forward.

Thus, the supply arm 30 is confined to a horizontal movement limited by the opening 34 at its rear end. At its front end, the arm 30 can have a slight vertical movement limited upwards by the stopper 32. Downwards, the movement of the front end of the arm 30 is limited, as will be described below .

An upward extension 40 (Fig. 2) of the arm 30 carries a threaded stud 42 extending perpendicularly to the outside and which is received in an opening of the drive arm 44. The front end of the drive arm 44 is split, as shown in 46, to receive the clamping screw CS of the needle clamping flange C.

A bracket 47, the lower end of which is fixed to the arm 30, a pressure washer 47a and a nut 48 are also received by the stud 42, so that the drive arm 44 is pressed firmly against the supply arm 30. As a result, when the needle moves in a vertical reciprocating movement, as in the sewing movement, the drive arm 44 oscillates around the stud 42. This causes an upward oscillating movement and down from the front end of the feed arm 30.

The cam roller 50 which is mounted for free rotation on an axis 52 of the arm 44 also controls the movement of the feed arm 30 and the drive arm 44. A cam surface 54 is provided in a slot 56 in the frame stationary 12. The cam 54 is shaped according to a peak 54a which,

when the roller 50 passes over it, causes the movement to the right (fig. 2) of the whole of the drive arm / feed arm assembly 44, 30. At this same instant, the feed arm 30 has plunged due to the friction cooperation of the descending drive arm 44 with the feed arm 30. A spring shoe 58, mounted on the frame 12, biases the roller 50 to the left. The spring shoe 58 is pivotally mounted on the frame 12 by a stud 60. The shoe 58 is biased to the left by a spring 58a disposed between the shoe 58 and the frame 12.

A feed knife is mounted on the front end part of the arm 30 and, when it moves down and to the right (fig. 2), it engages between adjacent closing elements E of the line of fasteners to move the entire line a short distance backward in the sewing machine.

In operation, the feed arm 30 preferably reaches its rear limit when the needle shaft reaches its lower limit. From this position, when the shaft rises, the arm 44 is driven upwards in correspondence. This causes the front end of the arm 30 to rise. When the needle N moves further upwards, the spring shoe 58 biases the arm 44 forwards (fig. 7), also driving the knife forwards.

It will be understood that, when the arm 30 and the knife 57 execute their movements by driving the closing line step by step through the machine, the needle N is synchronized with this movement to sew the closing elements E one by one to the fabric F.

The mechanism for cutting the line of slide fasteners E comprises the feed arm 30 and the knife 57, as already described. It will be noted that the straight end (FIG. 2) of the drive arm 44 is cut along a slot 62. On the other side of the frame 12 is mounted an electric solenoid 70 whose core is provided with a rod 72. The rod is biased in the retracted position by a spring 73 and a stop element 74 limits the path towards the rear of the rod (fig. 1).

When the solenoid 70 is excited, the rod is driven into the slot 62. The rod has a conical front end (fig. 2), so that, even if, as shown in fig. 2, the rod is not precisely aligned with the slot, the driving action by

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the solenoid 70 causes a jamming movement of the rod in the opening 62 to move the assembly of drive arms 44 and supply arms to the right. This is done against the action of the spring shoe 58.

The movement to the right, as described, results in the knife 57 taking a new position to the right (fig. 9) in which the knife is free to be driven entirely downwards to cut the connecting cords of the line of zipper elements between adjacent elements (fig. 9a). It will be understood that the knife 47 is normally held above such a lower level by the horizontal retaining guide 76 (fig. 9) comprising the upper surface of the cam 24. This guide normally prevents movement of the knife 57 to a level low enough that the closing line is cut. However, as shown in fig. 3, the guide 76 ends just to the right of the normal end of the path of the feed knife 57. Consequently, the normal reciprocating movement of the knife 57 is at a level where the cords, holding the closing elements E together, are not in contact with or cut by the knife; the knife normally engages only between adjacent elements E and advances the line of elements. It is only when the solenoid 70 is actuated and when the rod 72 enters the slot 62 that the assembly 30, 44 is driven to the right towards its limit which allows the cut-off position of the knife 57 .

It is clear that after cutting the cords M, the continuation of the actuation of the solenoid with the machine in operation causes a continuation of the sewing of the machine and the continuous advance of the fabric F, but not the supply of the line of elements E. This allows the machine to make the anchor points before and after stitching of the line of elements E.

The basic principles and the operation of the supply foot and of cutting of zipper lines having now been explained, the variant shown in FIGS. 10 and 11 can be easily understood.

In fig. 10 and 11, elements similar to those of the previous embodiment bear the same references marked with the index 'when such elements exist.

We first refer to fig. 10 which is a front view of a presser foot having a double means of feeding and cutting a closure line. In this variant, the frame 12 'supports a pair of cams 24' for spacing closing elements and element guide rails 26 ', 28' formed in the shoes 20 ', 18'. The front end of a feed arm 30 is provided with a pair of knives 57 '. As in the embodiment of fig. 1 to 9, the knives 57 ', when they are supported by the guides 76 and are driven in their movements, serve to make step by step lines of elements E' arranged side by side. When the solenoid, not shown, is excited, the arm 30 ′ and the knife 57 ′ move to their rightmost position and operate to the right of the guide 76 ′ to cut the cords of the closing lines simultaneously. With the device shown in fig. 10 and 11, closing lines arranged parallel side by side can be stitched directly to a thickness of fabric, as shown in fig. 12. As shown, the relative inclination of the two elements E ', shown in FIG. 10, arranges the closing lines in an opposite manner (FIG. 12), that is to say with the heads of the closing elements pointing outwards with respect to the other closing line. The intermediate product, therefore, is as shown in fig. 13, a pair of closure lines with their U-shaped openings opposite each other.

As shown in fig. 13, the fabric F between the elements can then be cut along a line parallel to and between the two lines (see the broken line CL in fig. 12 indicating the cutting line). In the following operation, during the garment manufacturing process, the fabric F can be folded to the positions FF just outside the lines of closure elements E ', thereby providing the following intermediate product shown in FIG. 14. A cursor X can finally be applied and the lines of elements E 'mesh through this cursor, as shown in FIGS. 16 and 15. A slider stop SS can be applied to the link 5 of the fabric and complementary seams can be made along the cut line, as is well known to technicians.

Thus, using the double application device described in FIGS. 10 and 11, it is possible to achieve economically, and i ° without the use of the usual intermediate ribbons, a closure of the invisible type attached directly to the fabric of a garment. Those skilled in the art will appreciate the elimination of the costly and time consuming intermediate steps including what was previously thought to be necessary, namely the provision of slide elements already attached to intermediate tapes. Obviously, the apparatus offers significant advantages over known methods.

Figs. 17 and 18 show, in the form of a block diagram, the control means of the device described.

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Referring to fig. 17, a keyboard is connected to a control and calculation device, which in turn is connected to the sewing machine motor, as well as to a cycle detector capable of counting the number of rotations of the main shaft of the sewing machine.

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In a commercial embodiment, the control and calculation device is in the form of a microprocessor and can be obtained from the company Pro-Log Corporation of Monterey, California, USA, under the model number PLS-402. 30 Complementary connections of the control and calculation device go to the point solenoid 70, to a start switch, to a digital display element indicating the number of points on which the control and calculation device is adjusted according to the length preprogrammed introduced by the keyboard and to a form circuit which establishes a general program for the operation of the machine.

Fig. 18 illustrates the method of operating the machine, using the means shown in FIG. 17.

As will be understood, prior to starting 4o of the sewing machine, the keyboard is used to introduce into the control and calculation device the information essentially comprising the desired length of the zipper. The pre-established shape circuit then establishes from this information the number of stitches involved and also supplies the control and calculation device with the number of end stitches which are used to stitch the tissue before and after the stitching. effective closing line, so that at either end of the line there are additional attachment points to prevent inadvertent separation of the ends so of the closing lines.

Following the instructions entered into the machine by the control and calculation device, the sewing operation begins with the solenoid 70 actuated. The operational setting of the solenoid causes, when the end of the needle 55 moves with an alternating movement, a simple alternating movement of the blade 57 in its cutting position without any effective supply of the line of elements of closing.

When the cycle detector has counted the appropriate number of prepoints, the control and calculation device automatically turns the solenoid 70 inoperative, so that, during the subsequent reciprocating movement of the needle, the drive arm 44 drives the feed arm 30 in the manner described above, that is to say somewhat following a hoe movement, feeding the closure line with each movement of 65 back and forth movements of the needle, with the needle sewing in correspondence of the individual elements with fabric F.

When the cycle detector has counted the predetermined number of rotations of the machine drive shaft

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sew which corresponds to the number of centimeters of zipper which must be fitted, the control and calculation device actuates the solenoid 70 to cause an operation of cutting the line of elements E as indicated above.

Finally, when the solenoid 70 is in operating condition and the knife 57 moving back and forth in its cutting position without feeding any line of elements whatsoever, the number of end points or postpoints is counted by the cycle detector before the machine stops.

The apparatus described allows significant savings in the manufacture of clothing, while improving the quality of the final product obtained.

4 sheets of drawings

Claims (5)

621,828 1. Apparatus for cutting the connecting cords of a line of zipper elements, after they have been sewn onto fabric in a sewing machine, characterized in that it comprises a blade driven by a reciprocating movement and being able to engage between adjacent elements of the closing line, an articulated mechanism driven by the sewing machine to animate the blade back and forth on a continuous path to feed the fabric and the slide elements step by step in the sewing machine and a mechanism that can be actuated at will to deepen the path back and forth of the blade to separate the connecting cords. 2. Apparatus according to claim 1, characterized in that the mechanism which can be actuated at will comprises a member actuated by a solenoid associated with the articulated mechanism and which is operative when it is excited to increase the path of movement of the blade towards the line of fasteners sufficient for the blade to pass through and cut the cords. 2 3. Apparatus according to any one of the preceding claims, characterized in that the blade has a hoe structure and is actuated with an alternating movement similar to that of a hoe so that the blade engages successively behind successive elements of the line of fasteners to pull them through the machine. 4. Apparatus according to claim 3, characterized in that it is arranged so that the path of movement of the blade in a direction towards the connecting cords is increased upon actuation of the mechanism which can be actuated at will. 5. Apparatus according to any one of the preceding claims, characterized in that it comprises a guide which is stationary relative to the blade and which has guide surfaces with which the legs of the respective closure elements cooperate to guide the elements through the machine with a head of the respective closure elements cooperating with the fabric and the legs of the elements moving away from the fabric.