US2096932A - Thread-controlling mechanism for sewing machines - Google Patents

Description

P. J. A-NTON Oct. 26, 1937.

THREAD CONTROLLING MECHANISM FOKSEWING MACHINES Filed Jan. 11, 1936 2 SheetsSheet l zlwuc/Mo'n Wyn webs: Perci val Jflnon Get. 26, 1937. P. J. ANTON 2,096,932

THREAD CONTROLLING MECHANISM FOR SEWING MACHINES Filed Jan. 11, 1936 2 Sheets-Sheet 2 Patented Oct. 26, 1937 UNITED STATES Application January 11, 1936, :Serial No. 58,639 i 3 Claims. (01. 112-4241) This invention relates to thread-controlling mechanism for sewing machines and more particularly to the overedge type of sewing machines as represented in patent No. 933,033, to A. Grieb and dated Aug. 31, 1909.

One of the objects of this invention is to provide an improved thread-controlling mechanism which will maintain the needle-thread taut so as to'cause the needle-loop to lie closely around the blade of the looper and thus insure an even tension on the thread. Another'object of the invention is to so reduce the size of the previously cast-ofif needle-100p that the looper will not enter the cast-ofi loop on its next loop-seizing movement A still further object of the invention is to.provide an improved thread controller which Will gently pull the thread from the supply, with the result that a light tension may be placed on the thread thereby reducing the, possibility of breaking the thread. 7

With .the above and other objects in View, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings:

Figure 1 is a front elevation of an over edge stitching machine embodying the invention, the work-plate being omitted to expose the mechanism below the same.

Figure 2 is a topplan View of the machine shown in Figure 1.

Figure 3' is a perspective view of a portion of the machine showing the stitch-forming and thread-controlling mechanism of the machine. 40 In the embodiment of the invention selected for illustration, I represents the base in'which is journaled in suitable bearings the main shaft 2 provided with a needle-actuating ball crank 3. Carried by the base I is a bracket-arm 4 pro- Vided with a head 5 formed with lateral bearing bosses 6 in which is fitted the reciprocating needle-bar 1 carrying a needle 8. Fixed to the needle-bar I is a collar 9 having a laterally ex-" tending lug l0 connected by means of'the link I l with the forward end of the needle-bar actuating rock-lever l2 mounted upon the fulcrum-pin [3 arranged at an angle to the horizontal and 'journaled in the bearing bosses I4 and having a rearwardly extending crank-arm I5. ,The crankarm [5 carries a ball lfiembraced by a strap I! at the upper end of the pitman I8 having at.

its lower end a strap 19 embracing theHballcrank 3 on the main shaft 2. From thevabove it will be observed that the actuating lever l2 op-, crates in a plane inclined upwardlyland backwardly to the vertical. v

'As shown, the machine is provided with a primary thread-carrying looper 2|] and a secondary thread-carrying looper 2 l .The needle operates through the usual needle-opening in the throatplate 22 in cooperation with the primary looper 20 which enters the needle-thread loops beneath the throat-plate, and the secondary looper. 2|

" which enters the primary looper loops and presents its own loops to the needle above the throatplate. The above, described mechanism is the same as that shown and described in the Grieb Patent No. 933,033, dated Aug. 31, 1909, to which reference may be had for a more detailed descripffi tion.

e In order 'to improve themechanism for maina 28, respectively. Adjustably mounted on the rock-lever 12 by the screws 29and slots 30 is a flat-sided thread-controlling finger 3| which extends upwardly between the'arms 21 and 28. The

fiat-sided thread-controlling finger 3| is ar- 7 ranged in a plane parallel to the plane of movement of the lever I2 and is formed with a suit:- able convex-shaped edge 32 which is adaptedto engage the needle-thread between the stationary eyes 21 and 28'.

The lead of the needle-thread A is as follows; from the supply through the apertures 24. in

the guide-plate 24, then betweenthe usual ten sion-disk's of the tension 25, the stationary eyes 21' and 28, the guide 33 and thread-check 34, both of which 'are carried'by the needle-bar I, and finally to the needle 8.

Assuming the parts ofthe machine to be in' the position shown in Figure 1, the needle being the stationary eyes 21' and 2B and movesit outwardly, the cam surface 32 being so shaped as to keep the thread under control at all times.

the thread and the needle-loop is maintained snugly about the blade of the primary looper 20. By maintaining the needle-thread snugly about the blade of the primary looper the needle-loop.

is reduced in size and consequently when the primary looper 20 is withdrawn from: the needleloop, this loop is too small to be accidentally seized, together with the needle-loop, by the primary looper on its succeedingneedle-loop seizing movement. 7

The stitch is set on the upstroke of the needle and the cam-edge 32 is so shaped as to gradually pull the thread from the supply through the tension 25. The gradual pulling of the thread from the supply permits the tension placed on the thread to be reduced thus minimizing the possibility of breaking the thread.

. From the foregoing description it will be obvious that the elements employed are susceptible of material variation. The privilege is therefore reserved of resorting to all such legitimate changes therein as may be fairly embodied within the spirit and scope of the appended claims.

Having thus set forth the nature of the invention, what I claim herein is:-

1. A sewing machine having, in combination,

a base, an overhanging bracket-arm fixed to said base and terminating in a head, 'a reciprocatory needle-bar journaled in said head and carrying a needle, a looper cooperating with said needle to form stitches, a needle-bar actuating lever piv- On further ascent of the needle the oted on said bracket-arm, means for actuating said lever, a member fixed to said bracket-arm and having two spaced parallel arms arranged in planes parallel to the plane of the bracket-arm, said arms being provided at their free ends with thread-eyes arranged in a plane at right angles to the plane of the bracket-arm, and a threadcontrolling finger fixed to said needle-bar actuating lever and extending upwardly between said arms, said thread-controlling finger having a thread-engaging cam edge.

' 2. In a sewing machine in combination, a base, a bracket-arm fixed to said base and terminating in a head, a reciprocatory needle-bar journalled in said head and'carrying a needle, a looper cooperating with said needle to form stitches, a

needle-bar actuating lever pivoted to said bracket-arm at'a point intermediate its ends, means for actuating said lever, a member carried by said bracketam and having two spaced parallel arms each arm being provided with a thread-eye, and

a thread controlling finger fixed to said needle-' baractuating lever at a point between the needlebar and the pivot point of said lever, said finger extending upwardly between the arms of said member and having a thread-engaging convexshaped edge.

3. A sewing machine having, in combination,

a base, an overhanging bracket arm fixed to said needle-bar actuating lever and having a thread, engaging convex shaped edge, said thread con trolling finger extending upwardly between the two spaced parallel arms of said member.

PERCIVAL J. ANTON.

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