US285536A

US285536A - John j

Info

Publication number: US285536A
Authority: US
Publication date: 1883-09-25
Anticipated expiration: 1900-09-25

Description

(No Model.)

J. J. WHEAT.

SEWING MACHINE. No. 285,536. Patented Sept. 25, 1883.

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UNITED STATES PATENT OFFICE.

JOHN J. W'HEAT, OF INDIANAPOLIS, INDIANA, ASSIGNOR TO CHARLES LILLY, OF SAME PLACE.

SEWING-MACHINE.

SPECIFICATION formingpart of Letters Patent No. 285,536, dated September25, 1883.

Application filed March 24, 1883. (No model.)

' and useful Improvement in Needle-Bar Movements for Sewing-Machines, of which the following is a description, referencebeing made to the accompanying drawings, in the several figures of which like lettersindicate like parts.

lVIy invention relates to an improved method of connecting the needle-bar of a sewing-ma chine with the actuating mechanism, and in such a manner that a short needle-bar can be used, and will be readily understood from what follows.

In the drawings, Figure l'is a view of my device in front elevation with the face-plate removed, showing the needle-bar inthe guides and the connection of the bar to the actuating mechanism. The dotted lines indicate the positions of the various parts when the needle is drawn up. Fig. 2 is a vertical section of the arm, showing the operating parts from a rear view.

In detail, A is the arm of the machine, Ow, a crank-wheel fixed upon the end of a revolving shaft; Or, a crank-rod working on a wristpin on the crank-wheel; R, abell-crank lever, to the short arm of which the crank-rod Or is connected, the bell-crank lever being pivoted' by a pivot, l, to the stationary arm at a point substantially midwaybetween the crank-wheel and the bottom of the arm in order to effect the return movement of the needle-bar at the proper moment; and Nbc is alink connected at its upper end to the long arm of the bell-crank and at its lower end to about the center of the needle-bar. The latter, as will be observed, is short andlight, thus preventing friction and the wearing away in spots, and offering less resistance than the long needle-bars commonly in use. Any lost motion in the needle-barcan be readily taken 'up by the adjustable guide and key shown in Fig. 1.

By pivoting my bell-crank lever at about the center, vertically, of the stationary arm I am enabled to hold my needle longer at rest without increasing the diameter of the crank at the driving-shaft than I could if the lever were pivoted higher up, audthis longer rest is desirable when a long shuttle is used, and it is this peculiar point ofpivoting that enables me to use the short needle-bar with good results.

The operation of my device is as follows: Power being applied to the revolving-shaft, the crank-wheel Ow revolves, and the crankrod revolves also, its center pivot describing the circle indicated by the dotted lines on the crank-wheel. The short arm of thebell-crank is drawn upward in an are indicated by the dotted lines, and the long arm describes a larger arc upward, also indicated by a dotted line. This movement carries the needle-bar connection Nbc toward the needle-bar and upward, and as it approaches the inner line of the guide the needle-bar will then, and not sooner, begin to lift, it being then at its lowest point of descent. This gives ample time for the shuttle to enter and pass through the loop of the upper thread. When the needle-bar is at its lowest point, the pivot that connects the,

link with it will be at the place indicated by the small dotted circle in Fig. 1, thus dropping the needle-bar about three-siXteenths of an inch below the position therein indicated.

WVhat I claim, and desire to secure by Letters Patent, is the following:

The needle-bar movement herein described, consisting of the combination and arrangement of a crank-rod connected at its upper end to a crank-wheel driven by a revolving shaft and at its lower end to the short arm of a bell-crank lever pivoted to the stationary arm at a point substantially midway between the revolving shaft and the lower end of the arm, the long arm of the'bell-crank lever connected by a link to the central part of a short needle-bar, substantially as and for the purpose described.

In witness whereof I have hereto set my hand this 16th day of March, 1883.

- JOHN J. WVHEAT. Witnesses: O. P. JACOBS,

(l. S. SPRI Z.