US1332031A - Stop-motion - Google Patents

Description

A. CRAWFORD.

STOP MOTION.

APPLICATION FILEP MAYII, 1912.

Patented Feb. 24, 1920.

fay/31% A UNITED STATES PATENT oEE o I ALFRED CRA FORD, or NEW BRo sWIcn, NEW JERsEY, AssIeNoR TO THE CRAWFORD MANUFACTURING COMPANY, or NEW BRUNSWICK, NEW JERSEY, A coRPoRA'no OF NEW JERSEY.

STOP-MOTION.

Specification of Letters Patent. i Patented Feb, 24, 1920,

Application filed May 17, 1917. Serial No. 169,258.

To all whom it may concern:

Be it known that I, ALFRED CRAWFORD, a citizen of the United States, residing in New Brunswick, Middlesex county, State of New Jersey, have invented a Stop-Motion, of which the following is a specification.

This invention relates to knitting machine stop motions, particularly of the type described and claimed in a Patent #1,17'2,950, dated Feb. 22, 1916, to Frank Crawford, Sn, and has to do more particularly with a novel arrangement of the tension producing means for the fork I or thread engaging member. v

One object of the invention is to so arrange the' connections between a spring and the fork actuating member usually within the head of the stop motion, that the tension on the fork shall be substantially constant instead of increasing, as said fork is, moved from its normal to its thread releasing position.

Another object of the invention is to so construct the thread holding portion of the fork as to cause it to release the thread with less angular movement than hitherto, when an abnormal tension is exerted upon said thread.

These objects and other advantageous ends I secure as hereinafter set forth,ireference being had to the accompanying drawings, in which,

Figure 1 is a plan of the head of a stop motion with the parts associated therewith,

showing my invention as applied to the apparatus;

Fig. 2 is a section on the line 2-2, Fig. 1; and

Fig. 3 is an elevation further illustrating one of the features of the invention.

In the above drawings, 1 represents a portion of the head of a well known form of stop motion for a circular knitting machine and this head has a horizontally projecting arm 2 carrying at its outer end a thread guard 33. Pivoted to said arm is a bell crank lever 1 preferably formed from sheet material and having a forked arm 5 extending adjacent the outer portion of the thread guard 3. Adjacent the outer end of j the arm 4 there is a branch 6 extending at right angles to its general line and said arm 1s pivoted on a screw 7 whose axis 18 inclined to the line of the arm 2 at an angle of from sixty to seventy-five degrees more or less. As a result, when the fork is turned on its pivot, its branched end swings down from what is practically a horizontal position and releases the thread after but a small angular movement has occurred.

The branched end of said arm extends immediately adjacent the outer portion of the thread guard 3' and the second arm 8 of the fork is likewise branched so as to be capable of engaging the downwardly inclined' end 9 of a spindle '10 rotatably mounted in a bearing of a lug 11 and also having a bearing in the side of the casing 1.

Fixed to this spindle adjacent the casingis a body of wire 12 having an angularlybent arm 13 for the support and guidance of the thread as it passes from the outer end of the branched 'arm 5 of thefork, downwardly between the fingers 14 of an arm 17 and a stationary frame '15. Thislatter device is of the well known form and consists of a wire 16 having a sheet metal plate 17 rigidly fixed to it and provided with a pair of slots 18 through which the fingers 14 are movable.

The arm 19 projects from a spindle 2Q journaled in a bearing in the side of the head 1, and extends into the same where it is connected to the well known apparatus for controlling the stopping of the knitting machine. The spindle 10 is acted upon by a device within the head 1 wherebv through its arm 9, the branched end of the fork is normally held in the position illustrated, immediately adjacent the thread guard 3 and beyond which it is prevented from pass ing by a stop 26. The detail arrangement of this portion of the device in the head constitutes one of the features of my invention and it includes a hub 21 iournaled on a spindle 22 and having projecting arms 23.

As shown in Figs. 1 and 2, each of these arms is curved and at its outer end has an opening for the reception. of one end of a coil spring :24 whose second end is connected to an arm 25 fixed to the spindle 10 through a spring coil. The hub 21 with its arms is normally maintained in a fixed positionon the spindle 22 by a screw 27 which extends into the head 1 from the outside thereof and is threaded intoa downwardly projecting lug on one of said arms;the

arrangement being such that rotation of said screw by turning the hub on the spindle will vary the tension of the springs '24 within certain predetermined limits.

As shown in Fig. 3, each of the arms 25 projects from its spindle 10 at an acute angle to the line of its spring 24 so that as it is turned by movement of the fork arm 5, away from the guard 8, the tension of the spring is but slightly increased. This is due to the fact that the arm normally extends in a line at an angle of about 45 of a line drawn from the, spindle through the point at which theaspring 24 is attached to the arm '23, so that as said arm swings toward its dead point position in which it would be parallelto said latter line, there is a minimum elongation of said spring. As a result of this construction the resistance to the turning of the fork on its pivot, under the action of a pull on the thread engagedthereby, remains practically constant instead .of largely increasing as is the case with the apparatus now vgenerally in use.

' Moreover by reason of the peculiar form of the branched .arm 5, of the fork, the thread is released after said fork has made but a relatively small angular movement as a result of an abnormal tension on the-thread.

It is especially to be noted that the thread receiving end of the fork not only extends in a substantially horizontal line and is so supported on its pivot as to be swung downwardly in a plane :at an acute angle to the horizontal, but in addition its extremity is downwardly sloped or pointed so that the thread willslip ofi' withthe utmost ease whenever the fork has been swung down through a comparatively small angle as a result of an abnormal tension.

I claim I 1. The combination in a stop mot-ion for knitting machines, of a spindle; *a thread engaging member connected to one encl of the spindle; an arm at the opposite end; a second spindle having an arm located some distance from the arm of the first mentioned spindle; and a spring connecting the two arms, the first mentioned arm being at an acute angle in respect .to line through the center of the first spindle and the point of attachment of the spring at the second arm so that on the movement of the parts the spring will have a minimum of elongation.

2. The combination a stop motion for knitting machines, of ahead; a horizontal arm projeoti from the head; a horizontal spindle exteiiging parallel with the arm; an arm on the outer end of the spindle; a thread member arranged at an acute'angle .to e spindle {and forked at its outer end to engage the thread; an arm on the inner end-of the spindle;- an arm within the head; means tor adjustin said arm; and a spring connecting the ad ustable arm with the arm .on the inner end oi? the spindle, said arm on the spindle being so 10- cated in respect'to the line of the spring that when the spindle is turned the spring willhave a limited amount of movement.

In witness whereof I affix my signature.

ALFRED CRAWFORD.

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