US3356054A

US3356054A - Apparatus for back tacking loose ends of sewing machine stitching, and the like

Info

Publication number: US3356054A
Application number: US449418A
Authority: US
Inventors: Wyndham F Southwell; Wehrmann Nicholas
Original assignee: L AND L Manufacturing Inc
Current assignee: L AND L Manufacturing Inc
Priority date: 1965-04-20
Filing date: 1965-04-20
Publication date: 1967-12-05
Anticipated expiration: 1984-12-05
Also published as: IL25577A; GB1069309A; FR1476367A

Description

Dec. 5, 1967 w. F. SOUTHWELL ETAL 3,356,054

' APPARATUS FOR BACK TACKING LOOSE ENDS 0F SEWING MACHINE STI-TCHING, AND THE LIKE Filed April 20, 1965 3 Sheets-Sheet l MIMI.

INVENTORS:

Dec. 5, 1967 w. F. sOUTHWELL ETAL 3,356,054

' APPARATUS FOR BACK TACKING LOOSE ENDS OF SEWING MACHINE STITCHING, AND THE LIKE Filed April 20, 1965. 3 Sheets-Sheet 2 Dec. 5, 1967 w. F. SOUTHWELL ETAL 3,356,054

' APPARATUS FOR BACK TACKING LOOSE ENDS OF SEWI MACHINE STITCHING AND THE LIKE 3 sheets sheet 5 Filed April 20, 1965 I /Z7 66 A2761 6 5 cs5 I (E6 TD mum/ W i c5A ATTORN Y5.

United States Patent 3,356,054 APPARATUS FOR BACK TACKING LOOSE ENDS OF SEWING MACHINE STITCHENG, AND THE LIKE Wyndham F. Southwell, Wilkesboro, and Nicholas Wehrmann, North Wilkeshoro, N.C., assignors of L & L Manufacturing, Inc., a corporation of Delaware Filed Apr. 20, 1965, Ser. No. 449,418 8 Claims. (Cl. 112-252) Many types of sewing machines, including trimming and overedging machines, are arranged to operate even at times when no fabric or other material is under the foot of the sewing machine. In such cases stitching tends to be formed, as by chaining off, prior to the sewing of scams or other stitches in the fabric, and this prior stitching remains as a loose end which is unsightly and which may tend to ravel. In order to prevent this unsightliness and/or the raveling thereof, this stitching needs to be caught into the fabric stitches before its free end is cut Oil. While such a loose end may be swung back manual- 1y into the part of a seam or other line of stitching to be formed in a fabric (for example a seam joining two pieces of fabric) that is a difficult operation to perform manually and is an exceedingly diflicult one to carry out with any degree of uniformity in successive pieces of fabric. In this connection it should be borne in mind that excessive looseness and excessive length between the point where the loose end meets the fabric and the point where it is back-tacked to the fabric is undesirable in the finished stitching. Lack of uniformity in the operation not only is undesirable in itself, but also results in various undesir able conditions in a certain proportion of the (joined or single) fabric pieces, or other material being sewn.

With the foregoing and other considerations in view, the present invention contemplates the provision of looseend pulling means (more specifically suction means) for catching up a loose end and carrying it along a course which, after sewing has started on a piece of material so that a thread extends upwardly therefrom, moves around the thread and crosses the intended course of seaming or other sewing on fabric pieces or other material to be sewn. Of importance in many instances is the holding of the loose end at a controlled and/or generally uniform degree of tautness while it is swung back and back tacked and, commonly, also cut.

Whereas, under manual operation, the back tacking step for the seaming of a ten-inch fabric portion may often consume up to 40% to 45% of the time of each seaming operation, the present invention permits the back tacking step to be performed in only to of the time required for each seaming operation, and in a much more uniform, accurate, and effective manner.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplified in the constructions hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:

FIGURE 1 is a fragmental top View of one form of device embodying the invention;

FIG. 2 is a front view thereof, partly in section and showing the swinging arm in a partially-swung position;

FIG. 3 is a detail view of the lower end of the swinging arm on an enlarged scale; 7

FIG. 4 is a diagrammatic view of the swinging arm, a loose end, and a partially-sewn fabric, at the time of the initiation of the swing of the swinging arm;

FIG. 5 is a similar view showing an intermediate stage in the rearward movement of the swinging arm;

FIG. 6 is a similar view showing the swinging arm at the end of its rearward movement;

FIG. 7 is a similar view showing the elements after the fabric has resumed its forward movement, the sewing machine resumed sewing, the cutter brought into operation, and the swinging arm ready to start its forward movement;

FIG. 8 is a perspective view on a larger scale showing the fabric after the loose end has been automatically caught and has been cut, and when the trim is in the process of being cut; and

FIG. 9 is a circuit diagram.

The exemplified apparatus comprises a conveyor 14) for carrying a pair of overlying pieces 11 and 12 of fabric (knitted fabric pieces to be seamed together, as exemplified) to and along a work plate 14 of a sewing machine 15 (which may be of any well known or suitable type) to be seamed or otherwise sewn. The sewing machine comprises a needle is from which a thread 17 extends, lower and upper looper means (not shown) from which there extend respectively, a lower looper thread 18 and an upper looper thread 1841, a brake 19, a presser foot 29, an upper cutter 22, and a lower cutter 23, assembled and operating in a manner Well known to the art, and adapted to sew a seam 24 on the fabric when a portion thereof passes the needle, but, when the pair of pieces of fabric has passed, to form a strand of unattached sewing extending between the trailing edge of a pair of leading pieces of fabric and the leading edge of a pair of following pieces of fabric. This strand can be cut, broken, or otherwise severed at a point rearward of a leading pair of pieces of fabric, but the loose end 25 extending forwardly of the following pair of pieces of fabric needs to be back tacked and (ordinarily also) cut off so that a part 26 of it is attached to the pair of fabric pieces by the subsequent sewing, and any remaining part 27 is cut off (and, desirably, disposed of). To this end the exemplified apparatus further comprises a swinging arm 30 in the form of a hollow tube having an opening 31 at or near its lower end, and carried on a hollow rotatable member 32 and swingable thereby against the pull of a spring 33 from a stop 34 at a position A, where it can pick up a loose end 25 which extends forwardly of a following piece of fabric, to a position B wherein it will draw the loose end around an upwardly extending portion of the thread 17, and across the path of sewing to be formed by the sewing device so as to be back tacked (and, in the present instance, to have the portion 27 thereof cut off by the cutters 22 and 23). After the arm 3'!) crosses the path of intended sewing, the foot 20 is dropped.

As exemplified, there is provided a flexible tube 35 leading to a suction device such as a vacuum pump (not shown) for providing a suction in the swinging arm 30 for drawing a loose end thereinto when it is in position A and for yieldably holding the loose end by the suction as the arm swings to position B, so as to draw the loose end across the path of future sewing and beyond the edge of the fabric, so that sewing by the sewing device thereafter will tie down the loose end by the sewing to be formed along a projected path of sewing on the fabric. In the present instance, the portion 27 of the loose end is then cut off by the cutters 22 and 23 (at the same time, in the present instance, that they cut the trim 36 off at the edges of the fabric pieces 11 and 12 beyond the seam) and is sucked up thru the tube 30 for suitable disposal.

The sewing machine is arranged to be started by the movement by the conveyor 10 of a pair of overlying pieces of fabric into the path of a light source PLl of an electric eye FBI, and forms on the fabric a line of sewing which, in the present instance is the seam 24 forming a continuation of the part 26 of the loose end 25. When, however, the fabric moves into the path of light to electric eye PE2, the brake 19 is actuated, stop ping the sewing device, and, after a short time-delay, raising the foot 20, which, in turn actuates a lever 38 which, in turn, actuates a limit switch LS which energizes a rotating solenoid 40 which causes the arm 30 to swing and to carry the loose end 25 rearward and under the foot, and then around the needle thread (and, if the needle is down, the needle itself) and across the intended path of sewing of the seam. When the arm 30 reaches the position B, it contacts a switch LS4 which resets the circuit, drops the foot to hold the loose end in place, and releases the brake to start the sewing device up again, andafter the portion 26 of the loose end has been sewn the portion 27 cut otfreturns the swinging arm to position A. As soon as it is cut off, the portion 27 will be sucked into the hollow swinging arm 30.

In this manner the loose end is back tacked by the succeeding sewing, to produce the result shown in FIG. 8.

When a pair of overlying pieces of fabric moves into the path of light to electric eye PE3 from a source above it, it will stop the sewing device unless another pair of overlying pieces of fabric has actuated the electric eye PEI to override PE3 and continue the operation of the sewing device.

By the exertion of a steady uniform pull on the loose end, either by a suction means as exemplified, or otherwise; the loose end can be pulled to just the degreeof tautness desireda tautness, for example, which will assure easy and effective back tacking, but which will be insufficient to pull up or back or otherwise displace the (right-hand upperFIG. 6) corner of the fabric piece to which the portion 26 of the loose end was originally and still is attached.

As will be seen from FIG. 9, line 115 and line 116 are connected to a power source (not shown). Line 116 connects to line 117 thru a on-oif switch 117a, and line 117 connects to line 118 thru a protective fuse 118a.

Line 118 then connects to a normally closed set of contacts C2A on a coil CR2. The other side of C2A, normally-closed contacts connects in series to a normally closed set of contacts C4A on a coil CR4 by line 119. Line 120 connects the normally closed contacts C4A t0 normally open contacts PIA on photocell PEI and also normally open contacts C1A on CR1 coil in parallel. Line 121 connects to photocell PEI contacts PIB and, in parallel, a set of normally closed contacts P3 on photocell PE3. Line 122 connects contacts PIB and P3 to (in parallel) the hold-in coil CR1, one side of the coil M which controls the operating motor (not shown), and an indicating light RA. The other side of CR1 coil, motor coil M, and indicating light RA are connected to line 115.

When coils CR2 and CR4 are deenergized and when contacts PIA are closed, voltage will then flow thru the contacts C2A of CR2 (lines 1I3119), C4A of CR4 (lines 119420), contacts PIA (lines 120-121), contacts P3 or PIB (lines 121 and 122), to the coil CR1, motor coil, and indicating light RA. Coil CR1 will then lock itself in thru its own contacts C1A (lines 120 and 121) until photocell PE3 is broken, or coils CR2 and CR4 are energized.

Line 118 then connects to normally open contacts P2 on photocell PEZ; also, in parallel, normally open contacts C2B on CR2. Contacts P2 and C2B are connected in parallel by line 123 to normally closed contacts on CSA time delay coil CR3T D. Line 124 is connected to one side of the coil of CH2, CR3 time delay coil CR3TD, and an indicating light RB. The other side of CR2 coil, CR3TD coil, and light RB are connected to line 115.

When photocell PE2 is closed, voltage is fed from line 118 thru the contacts P2, to CR3TD normally closed con- 4 tacts along line 124 to the coil of CR2, coil of CR3TD, and indicating light RB. CR2 then locks itself in, holding CR3TD and light RB thru its own contacts, (lines 118 and 123) until the time on time delay relay runs out, clearing the circuit thru the normally closed contacts C3A of CR3TD,

lines

123 and 124. Note that when coil CR2 energizes, it clears the first circuit by means of opening lines 118and 119.

When the time on CR3TD is at an end, line 118 is connected to line 125 thru normally open contacts C3B on CR3TD. There is also a set of CR4 normally open contacts

C4B connecting lines

118 and 125. Line 125 goes to the normally closed contacts of LS4. From the normally closed contacts of LS4, line 126 feeds the coil CR4, the coil F of the foot lift, and indicating light RC. The other side of CR4 coil, foot lift, and light are connected to line 115. Connected in parallel to line 118 are normally open contacts LS4a and normally open contact C-5B from which a line 127 runs to normally closed contacts C6 from which a line 127a runs to coil CR5 and coil CR6TD which are arranged in parallel and connected to line 115. The contacts C6 are under control of. the coil CR6TD and the contacts CSB are the holding contacts of coil CR5.

Voltage is then fed from line 118 thru the contacts C3B of CR3TD, along line 125, thru normally closed contacts L4A of switch LS4, along line 126 of the coil of CR4, foot lift coil F, and light RC. CR4 then locks in thru its own contacts C4B,

lines

118 and 125, keeping the foot lift coil F energized until limit switch LS4 is actuated by engagement of arm 30, opening L4A, opening CR4 contacts C4B and letting the foot pedal down. The engagement of switch LS4 by swinging arm 30 closes contacts L4B causing voltage to flow from line 118 thru line 127 and normally closed contacts C6 of time delay coil CRGTD energizing coils CR5 and CR6TD. The normally open contacts C5B are then closed holding the circuit in. CR6TD now starts to control a time delay.

Line 118 also connects to limit switch LS5 normally open ocntacts. Thru these contacts is line 128 to the coil BT of the back tack which is a rotating solenoid. The other side of the coil connects to line 115. The closing of limit switch LS5 is accomplished by the energizing of the foot lift coil. In parallel with limit switch LS5 are normally open contacts C5A controlled by coil CR5. After the timed delay by coil CR6TD, contacts C6 open thus clearing the circuit held in by CSB contacts. At the same time CSA contacts are closed by CR5 coil. LS5 contacts at this stage are open so that, when CSA reopens, the back-tacking coil ET is deenergized permitting the spring 33 to return the swinging arm 30 to position A. The circuit is now cleared for another operation when called for by a photocell PEI, by closing the contacts C4A of CR4 (lines 119 and Line 118 connects to a normally closed set of contacts C1B on CR1, from these contacts line 129 leads to the brake coil B. The other side of the brake coil is connected to line 115. Light RD is in parallel with coil B. The deenergizing of the brake coil is accomplished by energizing of CR1.

Line 118 is connected to one side of the light sources PLI, PL2, and PL3 of photocells PEI, PE2, PE3, the other side being connected to line 115.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. Apparatus for back-tacking a loose end formed prior to a sewing operation of a sewing device; comprising a sewing device, yield'able loose-end-pulling means movable along a course from a position in proximity to a loose end in advance of said sewing device, back past said sewing device, and across an intended path of sewing on material being sewn; means to move said pulling means along said course after a loose end of sewing has been formed and so as to cross said path after a few stitches have been sewn in the material and While the loose end is yieldably pulled by the pulling means; means to cause further sewing past a portion of such loose end while the loose end is yieldably pulled by the pulling means whereby the loose end is caught by such further sewing; and means to return said pulling means to its advance position.

2. Apparatus as in claim 1 wherein said pulling means is arranged to exert on said loose end a pull which is insulficient to cause it to pull out of place the portion of the material to which it is attached.

3. Apparatus as in claim 1 wherein said pulling mean is in the form of a suction means.

4. Apparatus as in claim 1 wherein means are provided for cutting off the free end of said loose end after the loose end is caught by said further sewing and before the operation of said returning means.

5. Apparatus as in claim 4 wherein means are provided for disposing of said free end after it is cut off.

6. Apparatus for back-tacking a loose end formed prior to a sewing operation of a sewing machine equipped with a sewing device and with start means and stop means therefor; comprising a sewing machine having a sewing device and a start means and a stop means, means to feed material to said sewing device; means to actuate the start means of the sewing machine when a piece of material to be sewn is approaching the sewing device thereof; suction means movable along a course from a position in proximity to a loose end in advance of the sewing device and the material to be sewn, past a thread running from the sewing device to the beginning of a line of sewing on a piece of material, and across the intended path of said line of sewing thereon; means to actuate the stop means of the sewing machine after a few stitches have been sewn in the material; means to move said suction means along said course after a loose end of sewing has been formed and so as to cross said path after the beginning of said line of sewing and while the loose end is held taut by the suction means; means to reactuate the start means to cause further sewing past a portion of such loose end while the loose end is held taut by the suction means whereby the loose end is caught by the further sewing; means to release the operative connection between the suction means and at least the caught portion of said loose end, means to return said suction means to its advance position, and means to actuate said stop means after the material has been sewn.

7. Apparatus for back-tacking a loose end formed prior to a sewing operation of a sewing device; comprising a sewing device, means for receiving and yieldably pulling a loose end which is in advance of a said sewing device and for moving the loose end back past said sewing device and across the intended path of sewing on material being sewn so as to cross said path after a few stitches have been sewn in the material and while the loose end is pulled, said means comprising an element movable transversely of a portion of said material to cause the loose end to cross said path while it is pulled; and means to cause further sewing past a portion of such loose end whereby the loose end is caught by such further sewing.

8. A device as in claim 7 wherein means are provided for determining the extent of stitching of the material prior to the movement of the loose end across the line of stitching.

References Cited UNITED STATES PATENTS 2,313,433 3/1943 Golden 112 -104 2,756,704 7/ 1956 Lawber 112254 2,849,974 9/1958 Tishler et al 1l2-254 X 2,858,783 11/1958 Lawber 1l2-254 X 2,989,935 7/1961 Butler 1l2252 3,123,033 3/1964 Weigert 112-197 JORDAN FRANKLIN, Primary Examiner.

J. R. BOLER, Assistant Examiner.

Claims

1. APPARATUS FOR BACK-TACKING A LOOSE END FORMED PRIOR TO A SEWING OPERATION OF A SEWING DEVICE; COMPRISING A SEWING DEVICE, YIELDABLE LOOSE-END-PULLING MEANS MOVABLE ALONG A COURSE FROM A POSITION IN PROXIMITY TO A LOOSE END IN ADVANCE OF SAID SEWING DEVICE, BACK PAST SAID SEWING DEVICE, AND ACROSS AN INTENDED PATH OF SEWING ON MATERIAL BEING SEWN; MEANS TO MOVE SAID PULLING MEANS ALONG SAID COURSE AFTER A LOOSE END OF SEWING HAS BEEN FORMED AND SO AS TO CROSS SAID PATH AFTER A FEW STITCHES HAVE BEEN SEWN IN THE MATERIAL AND WHILE THE LOOSE END IS YIELDABLY PULLED BY THE PULLING MEANS; MEANS TO CAUSE FURTHER SEWING PAST A PORTION OF SUCH LOOSE END WHILE THE LOOSE END IS YIELDABLY PULLED BY THE PULLING MEANS WHEREBY THE LOOSE END IS CAUGHT BY SUCH FURTHER SEWING; AND MEANS TO RETURN SAID PULLING MEANS TO ITS ADVANCE POSITION.