US1285310A - Thread-controlling mechanism for sewing-machines. - Google Patents

Description

J. R. MOFFATT.

THREAD CONTROLLING MECHANISMYFOR SEWING MACHINES.

APPLICATION FILED AUG.8. I917.

Patented Nov. 19, 1918.

2 SHEETS-SHEET I m: "mull: runs :0. Pnaro L J. R. MOFFATT.

THREAD CONTROLLING MECHANISM FOR sewme MACHINES.

APPLICATION FILED AUG.8. 19H.

, Patented Nov. 19,1918.

2 SHEETS-SHEET 2.

' anism for Sewing-Machines,

JAMES R. MOFFA'IT, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

THREAD-CONTROLLING MECHANISM FOR, SEWING-MACHINES.

To all whom it may concern:

Be it'known that 1, JAMES R. MOFFATT, a citizen of the United States, residing at Chicago, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Thread-Controlling Mechof which the following is a description, referencebeing had to the accompanyingdrawing, and to the figures of reference marked thereon.

' ;The invention relates to new and useful improvements in thread controlling mecha 'nisms for sewing machines and more particularly to athread controlling mechanism wherein a rotating member takes up and re-' leases thread and a releasing finger and a "check finger cooperate therewith in per forming the thread controlling functions.

An object of the invention is to provide a detachable bracket for supporting both the releasing finger and the check finger so that said fingers may be assembled on the bracket and thebracket quickly attached to a sewing machine or removed therefrom.

' ing'finger and the check finger, of the above" nmounted and said bracket 1s capable of be- .ing quickly attached or detached from the fingers carried thereby,

for immediately supporting the same, parts being separated to show the structure;

A further object of the invention is to provide a supporting bracket for the releascharacter, and means whereby both the fingers maybe vertically and simultaneously.

adjusted on said bracket, and independently adjusted horizontally.

A still further object of the invention is to providemeans whereby the check finger "may be angularly adjusted independently of the releasing finger.

These and other objects wlll lnpart be obvious and will in part be hereinafter more Figure 1 1s a vertical sectional View 7 through a part of a sewing machlne havlng my improvement attached thereto;

' Fig. 2 is a top plan view of the same;

Fig. 3 is a perspective View of the take-up cam, the operatingshaft therefor, the supporting bracket and the releasing and check the clamping screw for thebracket also being shown as separated from the bracket;

Fig. 4 is a perspective view of the releasing finger and check finger and the devicles t e Specification of Letters Patent.

which show by way of Patented Nov. 19, 1918.

Application filed August 8, 1917. Serial No. 185,065.

Fig. 5 is a side view of the take-up cam and the thread fingers, showing the thread just after it has been released from the shoulder of the cam by the releasing finger and as held by the check finger.

My improvement is directed to a thread controlling mechanism which is preferably used for the controlling ofv thelooper thread of a chain stitch sewing machine. The thread controlling mechanism, broadly, to which the invention is applied is shown and described in the patent granted to R. G. Woodward, November 27th, 1906, No. 836,849.

In said patent a rotary take-up cam operates to take up and release the looper thread, and cooperating with this rotary take-up cam is av releasing finger. which causes the thread to.be released from the shoulder of the take-up cam, and a thread finger which, for a certain period of time retains the thread after it is released from the shoulder of the take-up cam.

The present invention is directed particularly .tothe means for supporting the thread fingers. Said invention consists broadly in a detachable bracket on which both the releasing finger and the check finger are sewing machine, carrying with it both the thread fingers. {The releasing finger is,

mounted for vertical adjustment in the bracket and may also be'adjusted endwise I bracket and is also endwise adjustable in its supporting means. 1

Referring more in detail to the drawings, I have shown part of the sewing machine consisting of a bed plate 1 which carries suitable bearings in which is mounted the main shaft 2. Mounted on this shaft is a take-up cam 3 consisting of two spaced disks k4. At each side of the take-up cam is an arm 5 having a guide 6 for the looper thread. This arm is carried by a movable support 7. The take-up cam 3 is provided with a concentric thread retaining surface 8 and a non-concentric thread retaining surface 9. This non-concentric surface is disposed substantially radially of the cam and forms with the concentric surface a shoulder 10. There is also a second non-concentric thread,retaining surface 11. Cooperating with the take-up cam is a thread releasing finger 12 and a check finger 13. These thread fingers extend between the disks. The cam rotates in the direction of the arrow, as shown. in Fig. 1. The non-concentric surface will engage the thread passing through the thread guides 6 andwill take up thread. The releasing fingerslides the thread outwardly along this surface 9 and over the shoulder 10. The thread is released from the shoulder 10 just as the looper leaves the thread. loop and the position of the check finger 13 determines the amount of slack in the looper thread when the needle is reaching lower end of stroke andprevious stitch is being set and last needle loops pull up. The surface 11 controls the looper thread while the looper is at rear end of stroke to prevent too much slack by a bracket 14. This bracket 14 is secured to an upwardly extending lug or bearing 15 formed integral with the bed of the machine socket 17 in which is mounted the post 18.

Said post is adj ustably held in the socket by a set screw 19. The upper end of the post is provided with a head 20 which has a transverse opening to receive the shank of the thread releasing finger 12. Said shank is adjustable endwise of the head and is held in adjusted position by a set screw 21. Adjustably securedto the head 20 is a supporting bracket 22 for the check finger 13. Said head has a transverse opening 23. The bracket 22 has a depending ear 24: formed with an opening 25. A screw 26 is adapted to pass through the opening 25 and into the transverse opening Said screw is threaded into the opening in the head but the bracket is free to turn on the screw. By tightening the screw the bracket may be held in an adjusted position. Said bracket is provided with an opening 27 for the shank of the check finger 13 and the check finger is adjustable endwise in this opening. A set screw 28 serves as a means for clamping-the check finger in the bracket 22.

From the above description, it will be apparent that I have provided means for supporting the thread fingers which consistsv of a bracket adjustable so as to position the thread fingers properly between the disks of the take up cam. Both thread fingers are carried on a supporting post and are verti- Cally adjustable so that the thread fingers may be adjusted to properly position the same for releasing the thread at the proper time. The releasing finger can also beadj usted endwise in the supporting head there for and this together with the vertical adjustment of the releasing finger enables the releasing finger to be set so as to forcethe thread over theshoulder 10 just at the right time. The check finger may be angularly adjusted by shifting the bracket 22 and: it

also has an endwiseadjustment. This anguplace when the post is raised. This enables the proper setting of the check finger so. that the non-concentric portion 11 ofthe take up cam will pass the same atthe proper time and the thread be released.

In the drawings, I have shown my :improved thread controlling mechanism .applied to the control of the looper thread of the sewing machine. The looper is indicatedat 29. The looper thread is indicated at 1. This looper moves transversely of .theline offeed. The feeding dog isindicated at 30 and the needles are indicatedat 31. There are two needles shown. i

It is obvious thatminor changes in the details of construction may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described my invention, what,

I claim as new and. desire to secure by Letter's Patent, is

1. The combination of a take up cam having a thread. retaining surface, a releasing finger for releasing the thread fromsaid re taining surface, a check finger for holding the-threadafter it is released, a detachable bracket for supporting said releasing finger and'said check finger, means for supporting said releasing finger on saidbracket, where-Vv by it may be adjusted endwise thereon and means for supporting said check finger on said bracket, whereby it may be angularly adjusted and endwise adjusted thereon. 5

2. The combination of a take up cam hav ing a thread retaining surface, a releasing finger for releasing the thread from said retaining surface, a check finger for holding the thread after it is released, a detachable bracket, means for supportingsaid releasingfinger on said bracket, whereby it may be 3. The combination of a take up cam having a thread retaining surface, a releasing finger for releasing the thread from said retaining surface, a check finger for holding the thread after it is released, a bracket, a vertically adjustable post carried by said bracket, means for supporting said releasing finger on said post whereby it may be adjusted endwise thereon and means for supporting said check finger on said post whereby it may be angularly adjusted and endwise adjusted thereon.

4. The combination of a take up cam having a thread retaining surface, a releasing finger for releasing the thread from said retaining surface, a check finger for holding the thread after it is released, a bracket, a vertically adjustable post carried by said bracket, said post having a head at its upper end provided with an opening for the thread releasing finger, said thread releasing finger 20 check finger may be adjusted endwise therein 25 and means whereby said second bracket may b angularly adjusted on said post and held in adjusted positions.

In testimony whereof, I affiX my signature, in the presence of two witnesses.

JAMES R. MOFFATT. Witnesses:

STEDMAN THOMAS, J. H. MASLAND.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

Images