US2318200A

US2318200A - Automatic cutoff for sewing machines

Info

Publication number: US2318200A
Application number: US329114A
Authority: US
Inventors: Cobble Joseph; Cobble Albert
Original assignee: GERHARDT H RAUSCHENBERG
Current assignee: GERHARDT H RAUSCHENBERG
Priority date: 1940-04-11
Filing date: 1940-04-11
Publication date: 1943-05-04
Anticipated expiration: 1960-05-04

Description

y 1943- J. COBBLE ET AL 2,318,200

AUTOMATIC CUTOFF FOR SEWING MACHINES FiledApr'il 11, 1940 INVENT R F\ s. 1. JbSEP/I arroll Cobb/e ,s

y mes Alba)? Cobb/ Udwu (4 A TTORNE Y Patented May 4, 1943 UNlT AUTOMATIC CUTOFF FOR SEWING MACHINES Joseph Cobble and Albert Cobble, Chattanooga, Tenn., assignors, by direct and mesne assignments, to Gerhardt H. Rauschcnberg, Dalton, I

Application April 11, 1940, Serial No. 329,114

15 Claims.

Our invention relates to a device for clipping final loops on a tufting machine, and more particularly to a device for clipping final loops on a tufting machine by halting the operation of the needle and maintaining same in a raised position while the feed dog and cutter blade of the machine continue in operation to clip said final loops.

In the prior art, it has been customary for a tufting machine to always retain one or more uncut loops of thread upon the looper hook while the machine is in operation. These uncut loops prevent the thread from being pulled out of the fabric by the downward movement of the needle in forming the next succeeding stitch, and obviate the necessity of the costly gripper mechanism that was used with other types of tufting machines to prevent the thread from pulling out.

Whenever the operator reaches a point in the pattern where it is desirable to change threads or to end the pattern or for any other reason to terminate the formingof tufts at a particular point, it is necessary by some means to clip the remaining uncut loops that are held by the looper hook, so that tufts may be formed from these loops and so that the fabric may be withdrawn from the machine. The common practice is for the operator to rock the handwheel of the machine back and forth while trying to ease the fabric and uncut loops backward along the looper to a point where the cutter blade by reason of this rocking of the machine will clip the remaining loops. The extent of the rocking is limited by the operation of the needle, which must not be permitted to penetrate the cloth and form additional loops while the rocking is taking place. This method of clipping the final loops is awkward and consumes considerable time. It also results in a loosening of the thread held in the machine, and requires that the thread be properly tensioned again before renewing tufting operations.

It is generally desirable that the presserfoot be raised whenever the final loops are to be clipped, since the final loops are only clipped at points where the fabric is to be moved or the machine re-threaded. However, it is not desirable that the lifting of the presserfoot should result in clipping the final 100ps since the presserfoot is lifted frequently to turn the fabric when tufting is to be continued from the point of change in direction of the tufting row.

' Knowing of the above described diificulties and disadvantages of the prior art, our invention has for its object a means of disconnecting the needle from the needle driving shaft while the final loops held by the looper hook are clipped.

A further object of our invention is to maintain the needle in a raised position after it has been disconnected so that it will not interfere with the movement of the fabric, or the movement of the unclipped loops in'toa position where they can be cut by the cutter blade 'of themachine. I

A further object of our invention'is a means of lifting the presserfoot from the fabric simultaneously with the disconnecting of the needle drive shaft so that by a'single operation of the operator the presserfoot maybe lifted, and the machine put into condition for clipping the final loops,- and then removing the fabric.

A further object of our invention is a connection between the means of halting the operation of the needle and the presserfoot of the machine, such that while the halting of the needle will automatically raise the presserfoot preparatory to removing the'fabric; the lifting of the presserfoot by the customary handle will not put the machine into condition for clipping the final loops held by the looper hook.

Other objects and advantages of ourinvention will appear from the following description and the accompanying drawing, and the novel. features thereof will be particularly pointed out in the annexed claims. I

In the accompanying drawing;

' Figure 1 is an end 'viewof a tufting machine showing our invention thereon.

Figure 2 is a side view of the needle end of a sewing machine head with our invention thereon.

Figure 3 is an enlarged View of the latch, and pivotal'wedge by means of which the needle bar is connected and disconnected withthe needle drive shaft Figure 4 is an enlarged view of a looper hook and cutter blade of a tufting machine showing an uncut loop in the normal position.

Figure 5 is an enlarged view 'ofa looper hook and cutter blade showing the final loop in a position on the looper hook to which it is brought by the operation of our invention so that it will be clipped. i 5

Referring to the drawing in detail [designates a standard Singer sewing machine head such as is customarily used with tuftingattachments; gHead l carries the usual presserfoot bar2 and needlebar 3, upon the lower ends of which respectively are the usual presserfoot 4 and needle 5. A tufting attachment of any customary type is posiing looper hook 6 for catching and holding loops of thread 34 from needle 5, and cutter blade I for cutting threads from looper hook 5. As is customary blade I does not engage the entire length of hook 6 when brought into cutting engagement therewith, so that one or more uncut loops remain held upon the end of hook 6 and the thread therefore does not pull out of the fabric on the upward stroke of needle 5. See Figure 4. Bar 8 activated by the feed dog shaft of the machine holds feed dog 3|] which cooperates vvith presserfoot 4 to carry the fabric backward across the bed plate under needle 5.

Arm Ill is rigidly fastened to presserfoot bar 2 and presserfoot bar 2 and presserfoot 4 are urged downward by compression spring l3 which presses downward upon arm I0, so that presser foot 4 is pressed down upon feed dog 33. Presser foot 4 is lifted by raising arm 9 the irregular end of which abuts against the underside of arm 16 and serves as a lever to lift it and hold it in a raised position in opposition to the downward pressure of spring l3.

.1 Collar 26 is reciprocated up and drawn by a link 26 which connects it with the usual crank army 21' of the main drive shaft 28 of the sewing machine head. Sleeve is rigidly attached to collar 26, and is open on one side. Contained in the open side of sleeve 25 is latch 21 which pivots on pin28, the ends of which rest in openings in the sides of sleeve 25. Compression spring 29 abuts on needle bar 3 and the lower end of latch 21 so as to push the lower end of latch 21 away from needle bar3 and to urge the upper end of latch 21 toward needle bar 3. Collar 24 is rigidly held upon needlebar 3 by set screw 35. Collar 26 and sleeve 25 slidably engage needle bar 3. When collar 26 and sleeve 25 slide .upward along needle bar 3 to a point where the upper edge of sleeve 25 abuts against the lower end of collar 24,.latch 33 catches and firmly holds collar 24 as is shown in Figure 2, so that needle bar3 is then reciprocated up and down by reason .of the grip of sleeve 25, and latch 21 upon collar 24. Collar 24 is urged upward by the pressure of sleeve. 25 upon the underside of collar 24, and is pulled downward by the pressure of the offset .in latch 33 upon the upper side of collar 24.

Bracket 23 is fastened to' the end of head I by brad l4. Lever I1 is pivoted on bracket 23 by pin IS. The upper end of link 20 is fastened by pin H! to the end of lever which is farthest from needle bar 3. The lower end of link 20 is fastened to the reduced end 2| of cross bar 22,

'it will go, the reduced end 2| after traveling upward the length of groove l2 raises link II and presser foot 4 to the height that they are raised by lifting handle 9 to its highest position. However, when crossbar 22 is at its lowest position,

the raising of presser foot 4 by lifting handle 9 to its highest position does not affect crossbar 22 because stand ll only travels upward the length of groove l2 so that the reduced end 2| end of groove l2 instead of at the upper end of groove 2.

An end of lever l1 forms slanted wedge I8 which slants toward needle bar 3 and almost touches needle bar 3. When the rear end of lever I! is moved upward by raising crossbar 22, wedge l8 moves downward along, but not quite in contact with needle bar 3' until the slanted of bar 22 merely changes its relative position with respect to stand H by being at the lower edge of wedge l8 passes downward between needle bar 3 and the rear side of the upper end of catch 21, thereby forcing the upper end of latch 21 away from needle bar 3 in opposition to spring 29, and causing catch 21, to release collar 24. As long as wedge I8 remains in a downward position, catch 27 is unable to grip the upper end of collar 24, on the upward movement of collar 26 and sleeve 25. When wedge I 8 is so positioned, needle bar 3 ceases to be reciprocated by collar 26 and sleeve 25, which collar and sleeve slide freely upon needle bar 3, the upper end of sleeve 25 striking the lower end of collar 24 on each upward movement, so that needle bar 3 is knocked upward by sleeve 25, but is never pulled downward. Collar 3| fits rigidly upon the top of head I and permits needle bar 3 to slide within it, but collar 3| is of such size as to grip needle bar 3 firmly enough frictionally to hold it in a raised position when latch 21 is prevented from exerting a downward pull upon needle bar 3 by wedge I8.

Our invention is operated by lifting crossbar 2| while the tufting machine is in operation. Crossbar 2| may be connected with a knee bar or any other suitable handle or means for raising and lowering it. The raising of crossbar 2| raises the rear end of lever IT by means of link 20, causing the wedge end I8 of lever I1 to be lowered, so that latch 21 strikes wedge l8 as latch 21 moves upwardly near its highest point. Latch 21 is pushed away from the needle bar by sliding upward and outward on wedge l8, so that collar 24 is released and the needle bar is thrown upward. The friction of collar 3| and the hole in the sewing machine head through which the needle bar passes tend to hold the needle bar in a raised position or at least to retard its fall so that it does not fall downward as fast as sleeve 25 and latch 2'1 move downward. As the needle 'bar falls downward, it is met by sleeve 25 and latch 27 returning upward. Collar 24 may be clasped by latch 21 as latch 21 moves upward, but as long as wedge l8 remains in a downward position latch 27 is open at the top of its stroke and fails to clasp collar 24 to pull it downward. As long as wedge I8 remains downward, therefore, the needle is retained in a raised position by friction combined with repeated upward thrusts of sleeve 25.

The lifting of cross bar 2| to pivot wedge l8 downward raises the presserfoot by means of stand I I that is connected to the presserfoot arm. When bar 2| is lowered the presserfoot may be raised by handle 9 for turning the fabric without raising bar 2|, since groove I2 permits stand H to be raised a sufficient length to raise the presserfoot without affecting bar 2|.

While the needle and presserfoot. are maintained in a raised position the feed dogs, looper hook and cutter blade continue to work. Normally there remain on the looper hook one or more uncut loops, as shown in Figured which are held by that part, of the looper hook that extends beyond the cutter blade. After the presserfoot is lifted, the fabric is h81d dOWn upon the "feed dogs by these uncut loops which'are tensioned upon the looper hook. The feed dogs carry the fabric and the uncut loops backward until the loops reach a point shown in Figure 5, where they are clipped by the cutter blade. The fabric may then be withdrawn. 1

When it is desired to resume tufting, bar 2|, is

21 clasps collar 24 on its upward stroke and collar 24 is firmly held between clasp 21 and sleeve 25, causing the needle to reciprocate in the customary manner. I

Having thus described our invention, we claim: l. A method of clipping the normally unclipped loops held by a tufting machine looper hook comprising simultaneously disconnecting the -needle from the needle drive shaft and raising the presser foot, maintaining the needle in a raised position, continuing the operation of the feed dogs to carry the unclipped loops along the looper hook, continuing the operation of the cutter blade until all loopsare clipped.

2. In a tufting machine, means for halting the operation of the needle and maintaining the needle in a raised position while continuing the operation of the machine, a connecting element connecting said halting means with the presserfoot for lifting same simultaneously with the halting of the needle, means for clipping the loops held by the looper hook, said clipping means normally clipping some, but not all loops, held by the looper hook, means for carrying the unclipped loops held by the looper hook toward said clipping means, whereby to clip all loops held by the looper hook when the needle is halted and raised.

3. In a tufting machine, means for disconnecting the needle from the needle drive shaft, a connecting element having a slot connection for connecting said disconnecting means with the presserfoot, whereby the operation of said needle disconnecting means lifts the presserfoot, but the handle lifting of the presserfoot does not' operate said needle disconnecting means, means for clipping the loops held by the looper hook, said clipping means normally clipping some, but not all loops held by the looper hook, means for carrying the unclipped loops held by the looperhook toward said clipping means when the needle is disconnected, whereby to clip all loops held by the looper hook. Y

4. In a tufting machine, a sleeve element slidably engaging the needle bar, means for reciprocating said sleeve element, an abutting element rigidly attached to the needle bar and positioned above said sleeve element, spring latch means for fastening together said sleeve element and said abutting element, obstructing means for obstructing the closing of said latch means, said obstructing means being movable into and out of obstructing position, control means for moving said obstructing means into and out of obstructing position, a slotted connecting element connecting said control means and the presserfoot bar, whereby said control means lifts said presserfoot bar and the hand lifting of said presserfoot bar causes said connecting element to travel along said slot without lifting said control means, cutting means for clipping the loops held by the looper hook, and feed dog means for carrying the uncut loops into cutting engagement with said cutting means.

5. In a tufting machine, a sleeve element slidably engaging the needle bar and means for reciprocating same, an abutting element rigidly attached to the needle bar, above said sleeve lowered pivoting wedge l8 upward, so that latch element. for abutment upon the upper end of said sleeve element to drive the needle bar ,upward, a latch element for fastening said sleeve to the needle bar to reciprocate the needle bar, a lever the forward end of which moves down: ward to obstruct the closing of said latch means, a lifting bar connected with the rear end of said lever for turning said lever, a slotted link rigidly connected to the presser foot bar, said lifting bar traveling within the slot of said slotted link, said slot being of such length that the normal raising of said presserfoot bar does not lift said lifting bar, whereas the lifting of said lifting bar sufliciently to turn said lever into obstructing position lifts the presserfoot bar and presserfoot, cutting means for clipping the loops held by the looper hook, and feed dog means for carrying the uncut loops into cutting engagement with said cutting means.

6. In a tuftingmachinaareciprocating sleeve slidably engaging the needle bar, an abutting collar rigidly attached to the needle bar above said sleeve for abutment with the upper end of said sleeve on its upward movement to drive the needle bar upward, a spring latch attached to said sleeve for clasping and holding said collar to said sleeve, said latch being operated by the impact of said sleeve upon said collar, a lever that pivots upon a pin affixed to the sewing machine head, said lever having a slanting wedge end positioned to wedge between the upper end of said latch and the needle bar and thereby to open said latch near the top of its upward movement, releasing said collar, manually actuated means for pivoting said lever to open said latch and release said collar, whereby the needle is driven upward by said sleeve, but not. pulled downward by said latch and is thereby maintained in a raised position, cutting means for clipping the loops held by the looper hook, and

. feed dog means for carrying the uncut loops into cutting engagement with said cutting means.

'7. In a tufting machine a reciprocatingsleeve element slidably engaging the needle bar, an abutting element rigidly attached to the needle bar above said sleeve element for abutment with said sleeve element on its upward stroke, a spring latch upon said sleeve element for latching upon said abutting element when said sleeve element abuts against saidabutting element, an upwardly extending slanted head upon said latch, a wedge manually movable into sliding engagement with said extended latch head, whereby .said latch is opened on its upward stroke releasing said abutting, element, whereby to halt the reciprocation of said needle and maintain same in an upraised position while operating the loop cutting mechanism of said machine.

8. In a tufting machine a reciprocating sleeve slidably engaging the needle bar, a collar rigidly attached to the needle bar above said sleeve and being driven upward by said sleeve, a spring latch, upon said sleeve for clasping said collar, a wedge pivoted upon the frame of said machine, said latch being unclasped from said collar on its upward stroke by sliding engagement with said wedge, manually actuated means for pivoting said wedge into and out of sliding engagement with said latch, collar means for frictionally maintaining the needle bar in a raised position when said latch is released by said wedge, whereby to clip all loops held by the looper hook of said machine while the needle bar and needle are maintained in a raised position.

9. In a tufting machine a reciprocating sleeve slidably engaging the needle bar, an abutting element rigidly attached to the needle bar above said sleeve and being driven upward by said sleeve, a spring latch upon said sleeve for clasping said abutting element, a wedge pivoted upon the frame of said machine, said latch being unclasped from said abutting element on its upward stroke by sliding engagement with said wedge, control means attached to an end of said wedge forpivoting said wedge into sliding engagement with said latch and for pivoting said wedge out of said sliding engagement by lowering said con-c scribed comprising a sewing head carrying a reciprocating needle bar having a needle and a presser foot, means for raising said presser foot, work feed. means for progressively moving fabric through the machine, loop forming and holding 'means, means for normally clipping some but not all of the loops on the said loop holding means, and means responsive to movement of the presser foot raising means to disengage said needle from its drive and for rendering it in I operative while the feed means moves the fabric rearwardly and brings the uncut loops into clipping position with said clipping means.

11. In a tufting machinehaving a reciprocating needle bar and a presser foot, means for raising said presser foot, a sleeve slidably engaged with said needle bar, means for reciprocating said sleeve, an abutting element rigidly joined to the needle bar for engagement with .theupper end of the sleeve on its upward movement for driving the needle bar upward, latch means for fastening said abutting element to said sleeve and moving same downward, means re- .sponsive to movement of said presser foot raising means for controlling the operation of the latch means and disengage it'from said abut- .ment, looper means for forming loops, and cutter means for normally clipping some but not all the loops on the looper, and feed means for carrying all of the uncut loops into cutting engagement with the cutter while said latch is disengaged from said abutment.

12. In a tufting machine, a work support, work 'feedmeans, means todrive the work feed means,

a presser foot, a reciprocatory needle bar, a stop element mounted upon the needle bar, a sleeve slidable upon the needle bar'beneath the .stop element, a latch device for connecting the sliding sleeve with the needle bar so that the needle bar moves downwardly with the sleeve when the latch device is active, means to render the latch device inactive when the needle bar is raised, means to actuate the last named means and also serving to raise the presser foot, a looper to receive the loops from the needle, and a blade to sever the loops upon the looper during the sewing period and leave at least one unsevered 100p upon the looper.

13. In a tufting machine, a work support, Work feed means, a reciprocatory presser foot bar, a presser foot carried by the presser foot bar, a reciprocatoryneedle bar for carrying a needle, a looper to receive the loop from the needle, a blade to sever the loops upon thelooper during the sewing period and leave-at least one unsevered loop upon the looper, a linkconn-ected with the presser foot and having an elongated slot, a movable member having a part to enter the slot and spaced from one endof the slot, and means to stop the operation of the needle bar and operated by the movable member.

14. In a tuftingmachine, a work support, work feed means, a presser foot, a reciprocatory needle bar to carry a needle, a looper to receive the loops from the needle, a blade to sever the loops upon the looper during the sewing period and leave at least one unsevered loop upon the looper, means to operate the needle bar, means to stop the operationof the needle bar, a movable member to actuate the stopping means, and means effecting a lost motion connection between the movable member and the .presser foot.

15. In a tufting machine, a work support, work feed means, a presser foot to cooperate with the work feed'means, a reciprocatory needle bar, a

looper to receive the loops from the needle, a

blade to sever the loops upon the looper during the sewing period and leave at least one unsevered loop upon the looper, a drive-shaft, driv- 1 the needle bar, an element to raise the presser foot, and means to render said means inoperai 'tive with respect to lowering the needle bar and also serving to move the element and thereby