US2392793A - Means for timing loop-takers of sewing machines - Google Patents

Description

Jan. s, 1946.

A. WOQD MEANS FOR TIMING LOOP-TAKERS OF SEWING MACHINES Filed Sept. 4, 1944 2 Sheets-Sheet l Jan. 8, 1946. 2,392,793

MEANS FOR TIMING LOOP-TAKERS OF SEWING MACHINES R. woon Filed Sept. 4, 1944 2 Sheets-Sheet '2 .5. o lfi'ed 2000a l 6 2g SHouu/i,

Patented Jan. 8, 1946 MEANS :FOR. TIMING LQQPAEAK-ERS 49F- SEWING MACHINES Alfred 3- Wood. .Iirjideeport. Con assignor .t

he Sin er Manufa in Company E iza: 'beth. "N. J.,,' a corporation of New Jersey Applicat on September 19% Se ia -2 9, 5.5.2,;iiil

:1 Cla minv ntion relates to sewingmachines and more particularly to sewing machines in which the loop-taker operates in a circular path and cooperates with a reciprocatory eye-pointed In sewing machines of this kind, it is needle. essential to the perfect functioning of the machine that the beak of the loop-taker be accurately timed relative to the needle to insure that the beak enters the needle 1001) during each stitch-forming cycle, thereby to avoid defective stitching.

One of the objects of this invention is to provide an improved means for varying the position of the beak of the loop-taker in its orbital path, thereby properly to time the loop-taker beak relative to the reciprocatory needle.

Another object of this invention is to provide a simple and inexpensive device for accurately varying the timing of the loop-tzflzer relative to the needle and in which the device for varying the timing of the loop-taker acts as a counterbalance to reduce vibration of the machine.

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, fromwhich the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings,

Fig. 1 is a front elevation, partly in section, of a buttonhole sewing machine having my inven tion embodied therein.

Fig. 2 is an enlarged sectional view taken substantially along the line 22 of Fig. 1.

, IJI carriesacrank .15! rwhichds connected bygneans Fig. 3 is an enlarged sectional view taken along y the line 33 of Fig. 1.

Fig. 4 is an enlarged sectional view taken along the line 44 of Fig. 1.

Fig. 5 is a side elevation, and Fig. 6 is a top plan view of the member used to vary the timing of the loop-taker relative to the needle.

In the embodiment of the invention selected for illustration, the invention is' shown applied to a buttonhole sewing machine comprising a frame including a. bed I0 from one end of which rises a standard II carrying an overhanging bracket-arm l2 which terminates in a hollow head l3. Journaled in the bracket-arm I2 is a rotary needle-bar shaft l4 driven by means of gears l6 and pulleys I 5, which may be operatively connected through a belt to any suitable source of power. The other end of the needle-bar shaft of a link alt-to the --usual reciprocating bar I9 carrying an eye-pointed needle 20.

J ournaled in suitable bearings beneath the bed I0 is a hook carrying shaft 2| having *fixed to one of its ends a rotary hook 22 which is adapted to cooperate with the reciprocating needle 20 in the formation of lock stitches. Secured to the hook-shaft 2| and located beneath the standard II is a gear 23 which meshes with a gear 24 secured to the lower end of a vertical shaft 25 journaled in bearings 26 located within the hollow standard II. To the upper end of the shaft 25 there is secured a second bevel gear 21 which meshes with a gear 28 carried by the needle-bar shaft 14. The ratio of the gearing between the shafts l4 and 2| is as l is to 2 and, therefore, the shaft 2| makes two complete rotations for each complete rotation of the needle-bar shaft 14. v I

From the foregoing, it will be understood that the needle 20 reciprocates and the hook 22 retates in timed relation with the needle. In some instances it is necessary to change the timing of the hook relative to the needle and in order to simplify the hook timing and thereby permit mechanics in the field readily andeasily to time the hook relative to the needle, I have provided a member 30 formed with a circular opening 3| which is adapted to receive the shaft l4. The member 30 abuts the hub 34 of the gear 28 and is fixed to the shaft M by the set screw 32 and Pin 33.

The member 30 is formed with two spaced laterally extending ears 35, 36 which are adapted to overlie the hub 34 of the gear 28. The ears 35, 36 are provided with complemental set- screws 31, 38 which cooperate with a screw 39 carried by the hub 34 of the gear 28, the screw 39 being located between the spaced ears 35, 36.

With the above described construction, the rotary hook 22 may be adjusted or timed relative to the needle 20 in the following manner. The screws 39 and 40 which secure the gear 28 to the shaft I4 are backed off just enough to free the gear 28 from the shaft [4. Depending upon the direction it is decided to shift the hook 232 relative to the needle, one of the screws 31' or 38 is backed off a slight amount and the other screw is screwed in until the desired position of the hook-beak relative to the needle is obtained. The first mentioned screw is then screwed in until it engages the shank of the screw 39. The screws 39 and 40 are then tightened to further lock the gear 28 to the shaft [4.

From the above description it will be understood that a micrometer adjustment for varying the timing of the hook relative to the needle has been provided and that the hook may be adjusted relative to the needle from a point above the bed plate; It will also be'understoocl that a careful and accurate adjustment may be readily and easily made without thenecessity of turning the machine upside down or on its side for the purpose ofgaining access to the hook, and that it i is not necessary to loosen the hook 22 on its shaft and then turn the hook as has been the practice heretofore.

forma counterbalance which is utilized to bal-' ance the actuating mechanism and thus reduce vibration.

From the foregoing description it willbe apparent that my hook timing device may be located on the hook-shaft as well as the'needleprivilege is reserved of resorting to all such legitimate changes therein as may be fairly embodied in the spirit and scope of the appended claim.

Having thus set forth the nature of the inven tion, what-I claim herein is: 7 7

' A sewing machine having in combination, a frame comprising a bed-plate and anpverhang in g bracket-warm; a hook-shaft journaled beneath said bed-plate, a needle-bar actuating shaft journaled in saidbracket-arm, a gear carried by said needle-bar shaft and formed with a hub,'a mem- It will be observed that the mem- I :ber' 39 together with the ears 35, 36 are shaped to V bar shaft and'that the construction disclosed is susceptible of other variations. Therefore, the

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