US20686A - johnson - Google Patents

Description

A. I. JOHNSON. SEWING MACHINE.

Patented June 2 2 by. J.

.forms no part ofmy UNITED STATES PATENT OFFICE.

ALBERT E; Jomv'somor BOSTON, MASSACHUSETTS, ASSICNOR To EIMSELE ANDA FRANCIS E. EMEEY.`

IMPROVEMENT I N SEWING-MACHINES.

.Specication forming part of. Letters Patent No. 20,686, dated June 22, 1858.

To all whom it. may concern.'

Be it known that I, A. F. JOHNSON, 'of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Sewing-Machines, of which the following is a full, clear, and exact description, reference being had to the accom# panyingdrawings, making part of this specification, in -whichf- Figure 1 is a side elevation; Fig. 2, an end view. Figs. 3 and fare details to be referred to. I

My invention consists in improved mechanism for forming the loop and drawing up the thread, by which I'avoid the friction of many moving`parts,andam enabled toconstruct a sewingmachine more durable and eihcient than anywith which I am acquainted.

That' others skilled in the art may understand and use my invention, I will proceed to describe the manner in which I have carried it out.

In the drawings, AJ is the frame of the machine; B, the stationary arm, which carries the presser-bar; C, the vibrating arm, which carries the needle. v The lower branch, C', of this4 arm is connected by a crank, a, to a shaft,v D, which is supported in suitable bear- "ingsin the frame of the machine. This shaft is driven by a band and pulley, actuated by a treadle, or in anyv other suitable manner.- The shaft Dcarries, near 4one end, a cam, b, which actuates the feed-bar; but as this feed need not be more fully described.

Attached to the end of the shaft D, beneath the slot through'whichA the needle plays, is a hook-cam, E, of a peculiar form, (shown in detail in-Figs. 3 and 4,) by which alo'p is formedy in the thread after the needle has passed through the cloth, and the loop is held open until .the next stitch is made, when the thread is drawn up as'tight as required, the whole operation of forming the loop and drawing up.

the thread being'performed. by this one hookcam 4E, as willbepresently described. The p present invention, it;

vibrating needle-arm, being connected directly' tothe shaft which carries this looping and drawing apparatus, insures .the proper succession of movements. The camE iS formed, as shown in the drawings, with a hook, l, on its periphery, a deep groove or slot, 2, into which the needle descends after it has passed through the cloth, and la shallow groove, 3, which runs out on the outer face of the cani, forming a lip, 4, which catches the loop of thc thread and holds it distended mtil the hook has caught another loop and drawn it through this one, when, as the lip 4 comes round, the irst loop slips off from it and the hook l draws the second loop through the iirst, taking up, as the cam revolves, the slack of thethread, and drawing it sufficiently tight without any spri n g or other device for the purpose. The metal is cut away behind the hook and the different lpartsv are rounded oif, as shown, so that thc loop Slides from the hook l as the cam revolves, and is caught by thc groove Sand lip 4, and is'held distended, as in thj,e positionshownin Figs. 1 and 2.

The cam E Imay b e attached directly to the face ofthe ca b, or to the end ofthe shaft, or may be formd from the end ofthe shaft itself.

By the 'abo e-describcd improved machine I do away with-,a multiplicity of parts, which cause friction, are liable to dcrangement, and require nice adjustment..

What I claim as my inyention, and desire to secure by Letters Patent, is-

1. Taking the loop from the needle bya revolving hook, operating in the manner substantially as set forth.

2. In combination with the revolving hook 1 the groove 3 and thc lip 4, or its substantial `equivalent, 4for holding the lop distended,` in the manner substantially as de# scribed. l

ALBERT F. JOHNSON.

"Witnesses: i

Trios. R. ROACH, SAMUEL COOPER.

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