US129131A

US129131A - Improvement in feed-wheel-operating mechanisms

Info

Publication number: US129131A
Authority: US
Publication date: 1872-07-16
Anticipated expiration: 1889-07-16

Description

H. A. M. HARRIS.

Feed-Wheel Operating Mechanism.

Patented July 16, 1872. E91

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UNITED STATES 'PATENT OFFICE.

HARMAN A. M. HARRIS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO HIMSELF AND THOMAS E. GLENN, OF SAME PLACE.

IMPROVEMENT IN FEED-WHEEL-OPERATING MECHANISMS.

Specification forming part of Letters Patent No. 129,131, dated July 16, 1872.

To all whom it may concern:

Be it known that I, HARMAN A. M. HAR- RIS, of the city and county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Feed- Mechanism for Sewing-Machines, of which the following is a specification:

My improvements relate to the class of feed mechanism termed feeds-wheel, in which a serrated-edged wheel having an intermittent rotary motion feeds the fabric to the needle; and the object of my invention is to provide an improved friction-clutch for rotatin g the feed-wheel, as well as to afford means for compensating wear of the clutch.

In the accompanying drawing, Figure 1 is a view, partly in elevation and partly in section, of a feed-Wheel with my improvements attached; Fig. 2, a section through the same at the line :0 a: of Fig. 1; Fig. 3, a view in perspective of a friction-clutch detached; and Fig. 4, a similar view of the compensating-lever.

The feed-wheel A has a serrated rim, a which feeds the fabric to the needle, and a hollow boss or hub, a through which a spindle, A, secured to the table B in proper relation to the cloth-bed'U, passes, the feedwheel being loose upon the spindle A. A center block, D, provided with a lever-arm, D, and toe d, is journaled upon the hub a*. The lever-arm is operated by a cam, E, on a shaft, E, properly connected with the driv-.

ing mechanism of the machine, and is retracted after each stitch by the spring (1 The frictionclutches F, which transmit motion from the lever-arm to the feedwheel, bear against the edges of notches d in the center block D, and are provided with jaws, which embrace a flange, a on the feed-wheel. Springs f, attached to hooks f on the center block D, serve to keep the clutches F in close contact with the flange a and carry them around with the lever-arm when it is retracted by the spring (1 during which period the wheel re mains stationary.

As heretofore constructed a slot has been cut in the clutch, so as to form a jaw, substantially straight, or curved ,in correspondence with the rim a. This form of jaw operates successfully when new, but as its surfaces wear by use the slot becomes Wider, and the clutch slips upon the flange and fails to carry the wheel round with the lever-arm; My improved clutch is constructed with a circular recess, f, the center of which coincides with the center line of the flange a, and a slot, f transverse to the circular recess f and wide enough to fit easily upon the flange 01. The wearing surfaces are thus formed at the opposite corners of the intersection of the recess and the slot, and as the clutch wears along the side of the recess the sides of the jaw remain equivalent, and it continues to clamp the flange of the wheel without tendency to slip thereon. A jaw thus formed, moreover, gripes the flange more firmly than if provided with single bearing-surfaces-only.

The friction-clutches when new are set with a limited'amount of lead or advance of the radius which passes through their rear ends, and will be available until worn about a corresponding distance in rear thereof.

In order to utilize the entire circular jaw and compensate for wear thereon, I provide a compensating-lever, G. When the compensating -'lever is employed its toe G bears against the edge of the notch d of the center block D, and the clutch F is formed with a threaded stem, f, concentric with the recess f and is secured to the compensating-lever by a nut, f its free end resting in one of a series of grooves, g, formed in the compensating-lever. As the clutch wears the nut may be slackenedand the clutch moved back into another groove, thereby correspondingly varying its inclination with a radial line, and compensating for the wear upon the circular jaw. By this means the whole surface of the jaw may be made available and the durability of the clutch consequently increased.

To prevent displacement of the clutches from the flange I provide a plate, H, which rests upon the spindle A, and is held up against the clutches by the spring h, which serves to maintain the parts in proper relation without excessive friction.

I claim as my invention-- 1. The combination, with a feed-wheel for In testimony whereof I have hereunto'sub sewing-machines, of a friction-clutch, the jaws scribed my name. o

of which are formed with a circular recess and ,H. A. M. HARRIS. a transverse slot, substantially as set forth.

2. The combination, with a feed-wheel for Witnesses: sewing-machines, of a friction-clutch and com- J. SNOWDEN BELL, pensating-lever, substantially as set forth. J NO. H. HOGAN.