US1439468A - Thread-controlling mechanism for sewing machines - Google Patents

Description

G. s. GATCHELL.

Dec. 19, 1922.

I THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

3 SHEETS SHEET 1 FILED MAR. 10. 1921.

WITNESSES;

3 SHEE IS SHEET 2.

Dec. 19, 1922.

G. S. GATCHELL. THREAD CONTROLLING MECHANISM r05 SEWING MACHINES. FILED MAR. 10. I921.

WITNESSES:

Dec. 19, 1922. 1,439,468. G. s. GATCHELL.

THREAD CONTROLUNG MECHANISM FOR SEWING MACHINES.

FILED MAR. 10.1921. s SHEETS-SHED 3.

VIIIIIIIII'IIII WITNESSES: 4 INVENTO mm N 7 Patented Dec. 19, 1922.

UNITED STATES 1,439,468 PATENT OFFICE.

GEORGE S. GATCHELL, OF ROSELLE PARK, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A. CORPORATION OF NEW JERSEY.

"f' A THREAD-CONTROLLING MECHANISM :E/OR SEWING M ACHINES.

Application filed March 10, 1921. /Serial No. 451,188.

T 0 all whom it may concern:

Be it known that I, GEORGE S. GATCHELL, a citizen of'the United States, residing at Roselle lark, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Threadontrolling Mechanisms for Sewing Machines. of which the following is a specification, reference being had therein to the accompanying drawings. v

This in'iprovement relates to thread-controlling mechanism for sewing machines, more particularly of the chain-stitch type and has for an object to provide a compact thread controlling mechanism of simplified construction which in a chain-stitch machine will accomplish the delivery and the taking up of the looper-thread, to and from the looper, in the proper amounts and at the proper times during the stitch-forming cycle to insure the uniform and correct for mation of stitches with a minimum amount of the relatively expensive upper or needlethread and a maximum amount of under or looper-thread of poor quality.

A further object of the invention is to provide a looper-thread controlling mecha nism particularly adapted for installation in machines having the sewing point close to the standard or vertical member of the bracket-arm.

Still further. the invention has for an object to provide a looper-thread take-up which will permit the use of relatively weak looper-thread of poor quality and which will not tend to wind up the looper-thread, even though the latter should break while the machine is in operation. a

In the embodiment of the invention illustrated the objects of the invention are attained by mounting upon the oscillating looper-carrier a thread-guiding fork between the tines of which oscillates a thread cam mounted upon a vibratory looper-actuating lever. The cam is so shaped as' to cooperate with the oscillatory thread-guiding fork to take thread from and pay it out to the looper as required for the correct formation of stitches. The looper-carrier also supports a pair of looper-thread'nipper-springs which are depressed into contact relation with an adjustable stationary nipper-closing stop by the lateral motion of the loopercarrier in carrying the looper from one side of the needle 'to the other at the end of the loop-seizing stroke of the looper. The nipper-springs are thus held closed during the loop-shedding stroke of the looper. A suitable pull-oti' device is preferably provided for the looper-thread at the supply side of the thread-nipper and its function is to provide slack thread to be drawn through the open nipper by the advancing looper, so that the looper may go forward on a loose thread and thus avoid undue shortening of the previous looper looplying on the under side of the work.

In the accompanying drawings, Fig. l. is a side elevation of the bed of a sewing machine embodying the improvement, the needle being at its hi hest point and the looper fully forward. Fig. 2 is a plan View of the same. Fig. 3 is a perspective view of the looper-carrier. Fig. 4 is a perspective View of the oscillating support for the looper-carrier. Fig. 5 is a vertical sectional view through the bracket-arm standard transversely of the main-shaft. Fig 6 is .a view of the take-up elements at the period of the cycle when the needle is fully down and the looper retracted. Fig. 7 is a similar view with the looper advancing to seize a needle-gloop, and Fig. 8 shows the looper retracting and the needle entering the triangle 'formed by the looper-thread looper-blade and previous needle-loop.

In the specific embodiment of the invention illustrated. the sewing machine frame comprises a bed 1. bracket-arm standard 2 and head 3 in which the needleand presserbars are mounted; said bars carrying respectively, the needle 4 and presser-foot 5. The presser-foot 5 cooperates with a suitable four-motion feed-dog 6 which operates through the usual apertured throat-plate 7 let into the cloth-plate 8. It will be noted that, in the machine illustrated. the line of seam-formation represented by the. position of the needle 4, is close to the standard 2,

so that space between the sewing point and the standard 2 for working parts beneath the cloth-plate 8 is at a premium.

Cooperating with the needle 4, below the throat-plate T is the looper 9 which is mounted on the looper-carrier 10 formed with an apertured and split hub 11 which is journa led for rocking movement upon the lateral pin 12 secured in the split socket 12' block 16 on the eccentric 1? fixed to the main-shaft 18. This eccentric and the described connections therewith operate to im part the usual sidewise or so-called needleavoiding movements to the looper J.

The looper derives its loop-seizing or endwise movements through a train of connections including the link 19 joining the ball 20 on the looper-carrier with a similar ball at the upper end of the arm 21 of a bellcrank lever fulcrumed at 22 to the bed 1. T he other arm 23 of the bellcrank-lever is connected by the pitman 24 to one arm 25 of an upper bellcrank-lever fixed to and having for its fulcrum support the usual needle-actuating shaft 26. The other arm 27 of the upper bellcrank-lever is connected by the pitman 28 to the crank 29 on the main-shaft 18.

To avoid the danger of winding up the. looper-thread, the present looper-thread take-up is made oscillatory in character, rather than rotary. Also it is of a character such that it may be compactly installed in a short arm and bed sewing machine, where there would not be room for a rotary or other known looper-thread take-up. Mounted upon the looper-carrier is one element 30 of a take-up comprising coacting tl'iread-engaging devices, preferably the coacting thread-guide. and thread-cam type. In the embodiment of the invention illustrated the member 30 is the thread-guide member and is in the form of a fork, the tines of which are apertured at 31 to receive the looper-thread 1 The thread fork 30 is fixed relatively to the looper 9 and moves with the latter both endwise and sidewise.

Cooperating with the oscillating threadguiding fork 30 is the oscillating threadcam 32 having the active edge which passes between the tines of the fork 30. The cam 32 is mounted on an arm 34, which is adjustably secured by means of a slotand-screw connection 35 to a recessed seat 35, Fig. 5, in the arm 21 of the bellcranklever 21, 23.

The support 13 for the looper-carrier 10 is formed with a hub extension 36 on which is mounted the pair of thread-nipper springs 37 extending parallel -to the rockshaft 14. v The opening and closing action of the springs 37 is controlled by a stopscrew 38 which is adjustably threaded into the bed 1.

A free supply of slack loo .)er-thread may be assured if desired by providing a pull-off device comprising a pair of spaced arms 31) mounted on the pitman28 and projecting forwardly through a slot 10 in the front side of the standard 2. Bisecting the slot 40 is a cast-oti' plate a1. Mounted on the standard 2 at the sides of the path of motion of the pull-off arms 39 are the thread-guides As the crank 29 revolves, the free ends of the arms 39 are moved in an egg-shaped path, as shown in Fig. 5, and seize the looper-thread between the guides 12, lifting said thread until the latter is cast oli' of the ends of said arms by the outwardly and upwardly inclined edge '43 of the cast-off plate 11. The pull-oif action is timed to occur when the nipper-springs 37 are closed, thereby providing a bight of slack thread which is drawn through the Dipper-springs by the looper or take-up, when said springs are open. The amount of thread pulled off may be varied by adjusting the threadguides -12 and the cast-off plate vertically; adjustable screw and slot connections 42 being provided for this purpose.

The operation of the take-up elements 30, 32, is substantially as toll0ws:.'-Starting in the position shown in Fig. (3 with the needle down and the looper retracted; as the looper advances to seize a needle-loop, the rising thread-eyes 31 and forwardly tilting edge 33 of the cam 32 operate to absorb thread and take up the thread in front of the eye of the looper, thereby preventing buckling of the looper-thread. As soonv as the looper beak is well into the needle-loop, or a little past the position shown in Fig. 7, the thread betweenthe guide-eyes 31 slips over the central hump of the cam-edge 33 andslack is afforded so that the looper may go forward to the end of its stroke, on a slack thread. \Vherrthe looper reaches the end of its loop-seizing stroke, Fig. 1, substan tially all the slack looper-thread has been absorbed by the looper. As the looper moves'sidewise in the early stage of itsretracting stroke, the nipper springs 37 are closed and the descending thread-eyes 31 coact with the cam-edge 33, to take up the thread given up by the retracting looper, as shown in Fig. 8. After the needle has entered the loopcrloop. the thread between the guideeyes 31 slips downwardly over the central hump of the cam-edge 33 and slack looper-thread is afforded to permit the needle-loop to be readily and fully tightened so as to draw the requisite amount of slack looper-thread into the stitch being formed. By the means described, correct formation of the stitches is assured without straining the looper-thread: the needle-loops being fully drawn up and only the tips thereof being visible at the under side of the work. The use of a maximum amount of looperthread and a minimum amount of needlethread is thus assured.

The invention is not to be understood as limited to the precise construction and arrangement of parts'shown and described as. various modifications within the scope and spirit of the invention will doubtless be suggested to those skilled in the art from the foregoing disclosure.

Having thus set forth the nature of the invention, what I claim herein is 1. Looper-thread controlling mechanism for sewing machines comprising .a threadcarrying looper having the usual endwise and sidewise movements, and a looper-thread take-up including coacting thread-engaging .devices one of which is fixed relative to said looper.

2. Looper-thread controlling mechanism for sewing machines comprising a threadcarrying looper having the usual endwise and sidewise movements, and a looper-thread take-up including coacting thread-guide and thread-cam elements, one of which is fixed relative to said looper.

3. In a sewing machine, in combination, a reciprocating needle, a thread-carrying looper, a thread-guide moving with said looper and an oscillating cam cooperating with said threadguide to control the looper-thread.

4. In a sewing machine, in combination, a reciprocating needle, a thread-carrying looper, a looper-carrier, an oscillating lever and connections for imparting loop-seizing and shedding movements to the loopercarrier, and cooperating thread-cam and threadguide elements mounted on said looper-carrier and oscillating lever.

5. In a sewing machine, in combination, a

reciprocating needle, a thread-carrying looper, coacting looper-thread guide and cam elements mounted to oscillate about independent fulcra, and means for oscillating 'said thread-guide and cam elements in time with the needle and looper.

6. In a sewing machine, in combination, a looper, a looper-carrier, a thread-guiding fork mounted on the looper-carrier and an oscillating thread-cam operating between the tines of the thread-fork to control the looperthread.

7. Looper-thread controlling mechanism for sewing machines comprising, a looper, means including a looper-carrier for imparting the usual loop seizing and sidewise movements to the looper, and coacting thread-guide and thread cam elements vfor the looper thread, one of said elements being mounted on the looper-carrier.

8. Looper-thread controlling mechanism for sewing machines comprising, a looper, means including a looper-carrier for imparting the usual loop-seizing and sidewise movements to the looper, a thread-guide mounted on the looper-carrier, and a thread cam cooperating with said guide to control the looper-thread.

9. Looper-thread controlling mechanism for sewing machines comprising, a looper, means including a looper-carrier for imparting the usual loop seizing and sidewise movements to the looper, a thread-guide mounted on the looper-carrier, and an oscillatory thread-cam cooperating with said guide to control the looper-thread.

10. Thread controlling mechanism for sewing machines comprising coacting threaduide and thread-cam elements mounted to oscillate about spaced axes, and means for oscillating said elements synchronously;

ll. Thread-controlling mechanism for sewing machines comprising coacting threadguide and thread-cam elements mounted to oscillate" about spaced axes, and means for oscillating said elements synchronously and simultaneously in the same angular direction about their respective axes.

12. Thread-controlling mechanism for sewing machines having, in combination, a pair of pivoted arms, a link connection between said arms, means for oscillating said arms, a thread-guide mounted on one of said arms, and a thread-cam mouinted on the other of said arms in cooperative relation with said thread-guide.

13. In a sewing machine, in combination, a thread-carrying looper, a looper-carrier, a rocking support for the looper-carrier, a thread-nipper mounted on said rocking sup port. and a looper-thread takeup including coacting thread-cam and thread-guide elements one of which is mounted on and derives its movement from the looper-carrier.

1&.' In a sewing machine, in combination, a looper, a looper-carrier, a rocking support for the looper-carrier, a pair of tl'n'ead-nipper springs mounted on said support in substantial parallelism with the axis of rocking motion of the latter, and a stop coacting with said springs.

In testimony whereof, I have signed my name to this specification.

GEORGE S. GATCHELL.

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