US2210893A - Sewing machine - Google Patents

Description

B. BREGMAN SEWING MACHINE Aug-13, 1940.

Filed Sept. 3, 1937 2 Sheets-Sheet l Aug 13, 1940' B. BREGMAN 2.210,893

SEWING MACHINE Filed Sept. 3, 1937 2 Sheets-Sheet 2 Patented Aug. 13, 1940 PATENT OFFICE SEWING MACHINE Ben Bregman, Leeds, England Application september 3, 1937, seria No. 162,378 In Great Britain September 9, 1936 4 Claims. (C1. 11a- 176)y This invention relates to sewing machines for producing a chain stitch formed of concatenated needle and looper threads, said machines being of the kind in which a needle is pushed through the material and withdrawn so as to leave be.- hind a loop of cotton which is then pierced by a threaded looper and carried over to the point of entrance of the needle in the cloth where the looper cotton is then pierced by the needle, a spreader coming into operation by passing from above downwards and catching and holding the looper cotton down to enable this to take place.

In this kind of machine the spreader has been operated in vertical guides by a lever and cam mechanism, the cam being actuated from the main shaft of the machine through the medium of a countershaft geared to the main shaft by helical or other spur gear, whilst the looper has been carried by a rod connected at one end to an eccentric on the main shaft of the machine and suspended or supported at a point near its other or looper end in a universal bearing at the lower end of a depending arm pivoted to the machine frame, the arrangement being such that the looper has a lateral semi-circular motion, re-

versing at the two extremes, in addition to a toand-fro longitudinal motion. v

Now the object of the present invention is to simplify this kind of machine with a view to minimising noise in operation and obviating any risk of the spreader fouling the looper or the needle when working at high speeds.

According to the invention, the spreader is operated by the looper motion instead of by a separate drive from the main shaft of the machine.

In order` that the invention may be clearly understood and readily carried into effect, the same will now be more fully described with reference to and by the aid of the accompanying drawings, wherein:

Figures l and 2 are respectively a side elevation and a plan View of a sewing machine constructed in accordance with the invention.

Referring to the drawings, the machine is of the kind in which the curved needle I is pushed through the material and withdrawn so as to leave behind a loop of cotton which is then pierced by a threaded looper 2 and carried over to the point of entrance of the needle in the cloth where the looper cotton is then pierced by the needle I, a spreader 3 coming into operation by passing from above downwards and catching and holding the looper cotton down to enable this to take place.

The needle I is carried by an oscillating or swinging arm 4 ixed to a rockshaft 5 which is actuated by an arm 6 and an eccentric strap I which is mounted upon an eccentric 8 on the main driving shaft 9 of the machine.

The looper 2 is carried by a rod I0 connected at one end by a pivotal joint II to a sleeve I2 freely revoluble upon the inclined pin I2x on a crank disc or eccentric I3 on the main driving shaft 9, and the said looper rod I is suspended or supported at a point near its other or looperV end by a universal ball joint connection I4 with the lower end of a'depending arm I5 which is pivotally mounted by means of a bearing boss I6 on a pin or stud I'I 'lxed to the machine frame I8, the arrangement being such that the looper 2 has a controlled lateral semi-circular motion, reversing at the two extremes, in addition to the to-and-fro longitudinal motion imparted to it by the eccentric I3.

The spreader 3 is formed integrally with the outer or forward end of a lever I9 whereby it is pivotally mounted upon a pin or stud 2D fixed to the machine frame I8 at a short distance to the rear of, or to one side of the pivotal mounting of the depending arm I of the looper motion, and the spreader 3 is given a controlled up and down motion in synchronism with the looper motion by means of a pin 2I carried by a crank disk 22 which is xed to the pivotal bearing boss I6 of the depending arm I5, said spreader operating crank pin 2| being engaged in a cam slot at 23 formed in the spreader lever I9. The pin or stud may be eccentrically carried by a member 24, as shown, which can be rotationally adjusted in a `bearing in the machine frame I8 so as to enable the degree of movement of the spreader 3 to be varied, and also for this purpose the disc 22 is preferably rotationally adjustable upon the pivotal bearing boss I6 of the depending arm I5. Conceivably the spreader operating pin 2l may be mounted directly upon the depending arm I5, and it may be adjustable along it, instead of being carried by a disc such as the crank disc 22. The spreader 3 is of offset form or cranked, so as to give the necessary clearances for the looper 2 and needle I and for the depending looper arm I5 and associated mechanism.

It will be seen that with the present invention the construction is considerably simplified in that a countershaft and associated spur gearing for operating the spreader are dispensed with, whilst the spreader drive is rendered more positive and is in absolute synchronism with the looper motion which operates it.

I claim:

1. In a sewing machine of the character described, a main shaft, a looper mechanism operated from said main shaft, said looper mechanism including an oscillating depending arm, a pivotally mounted spreader, said spreader having a pin and slot driving connection With the depending arm of the looper mechanism.

2. In a sewing machine of the character described, a machine frame, a spreader pivotally mounted on the machine frame, a looper mechanism including an oscillating depending arm, said spreader having a cam slot therein, a pin associated with the depending arm of the looper mechanism to engage the cam slot in the spreader so that oscillation of the depending arm With the looper mechanism Will cause the spreader to have up and down motion in synchronism with the motion of the looper.

3. A sewing machine according to claim 1 wherein the pivotal mounting of the spreader comprises a pin adjacent the pivot of the depending arm of the looper mechanism.

4. A sewing machine according to claim 1 wherein the spreader actuating pin is carried by a crank disc on a pivotal bearing boss of the depending arm of the looper mechanism.

BEN BREGMAN.

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