US231568A - Sewing-machine - Google Patents

Description

G. P. HARLOW. Sewing Machine.

No. 231,568. Patented Aug. 24, 1880.

UNITED STATES PATENT OFFICE.

OHARLES F. HARLOW, OF BOSTON, MASSACHUSETTS.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 231,568, dated August 24, 1880.

Application filed August 18, 1879.

T 0 all whom it may concern:

Be it known that I, OHARLEs F. HARLOW, of Boston, Massachusetts, have invented certain Improvements in Sewing-Machines; and I do hereby declare that the same are fully described in the following specification and illustrated in the accompanying drawings.

The object of my improvements is to simplify and cheapeu sewing-machines, and to render their operation more satisfactory than those heretofore used.

My improvements relate to the shuttle mechanism and to the means for actuating and regulating the feed apparatus.

My invention consists in the devices and combinations of devices set forth in the appended claims.

In the drawings, Figure 1 is a plan of the under side of the bed-plate of my sewing-machine with the mechanism attached thereto. Fig. 2 is a vertical section of the inverted machine on line 00 as of Fig. 1; and Fig. 3 is atop view of the eccentric and cam, right side up, with the bed-plate removed, showing the essential shape of the cam-groove.

A is the bed-plate of the machine, and a a curved rib formed integral therewith and project-ing vertically downward, so as to form an upright wall for the outer face of the shuttle to bear against as it vibrates in a short are.

B is a shaft passing vertically through the bed-plate, and having motion imparted to it in any suitable manner.

0 is a cam-wheel secured upon the shaft B, and having in its horizontal upper or lower surface a recess or groove of the form indicated in Figs. 1 and 8 of the drawings, for the purpose of giving the required movement to the shuttle, and also of allowing it a certain period of rest equal to and corresponding exactly with the time occupied by the needle in forming the loop through which the shuttle passes.

D is the shuttle-lever, bent or formed with an elbow and pivoted to the table at E, and engaging by a stud or sleeve at one end with the groove of the cam 0, while at the other end a cradle, d, is formed, open at the top for insertion of the shuttle, and on the outer side toward the curved wall a to permit the shuttle to bear against the said wall, but supporting or carrying the shuttleby means of the bottom and ends of said cradle as the lever is vi brated back and forth with every revolution of the cam O. The shuttle being carried in the cradle cl is subject to friction only against the vertical wall of the rib a, and no race is required in which it would otherwise be driven forward and back with friction on two or three of its sides.

The shaft B also bears an eccentric, G, which is embraced by a strap at the end of a lever, H, which lever passes between the knife-edges of a fulcrum-block, l. with a screw passing through a slot in the table A, and wit-h a nut, J, by means of which its position may be varied at will or fixed permanently.

The lever H, having a suitable hearing, it, is formed with a bend or offset, H, which passes diagonally through the feed-bar K, bearing the roughened feed-surface K, and the feed-bar is provided at its other end with a short slot, through which its pivot passes.

From this construction of the parts it follows that rotation of the eccentric G will actuate the bent lever H and thefeed-bar, the lip-anddown movement of the feed-surface being due to the reciprocation back and forth of the bend or ofi'set H through the feed-bar K, while the forward-and-back movement of the feedsurface is produced by the lever H playing freely through the fulcrum I. In this simple manner I give to the feed-surface K four positive m0tionsup, forward, down, and backwithout any spring action.

The rapidity of the feed, and consequently the length of the stitch, is regulated by adjustment of the fulcrum-block by means of the nut J or otherwise.

I usually provide the fulcrum with a long slide-bar, I, with which the clamp-screw engages, so that the nut J may not be in the way of the operator in using the machine.

The fulcrum-block may be merely slotted to receive a pin projecting from the lever H, or it may be swiveled to permit the desired movement of the lever.

The movement of the fulcrum itself is upon a rod, L, parallel to the table A and lever H, whereby milling a path for it on the under side of the bed-plate is avoided. The rod L is This block is provided mounted in brackets or proiections beneath the bed-plate A, or its ends may be bent and inserted in holes in the table.

This simple contrivance effects a material saving in labor, the rod L being of ordinary round iron, and passing through a hole drilled of proper size in the block I, instead of which the usual method is to mill four sides of an angular bar and the corresponding faces of the ways for such bar.

1 do not deem it necessary to describe in detail the parts of a sewing-machine not shown in the drawings, since it is obvious they may be of ordinary construction and arranged in any manner adapted to the requirements of shlittle-machines, and that variations therein would not materially affect the operation of my im u'ovements.

I claim as of my invention-- 1. The shuttle-driving mechanism hereindescribed, consisting of a single bent lever, I), of the first class, pivoted to the under side of the bed-plate, and having a cradle, II, at one end to receive the shuttle, in combination with a vertical driving-shaft and a horizontal camwheel thereon, provided with a groove having a convex curvature, flattened on one side, as shown, with which groove the lever l) engages by means of a stud or roller thereon at the end opposite the shuttle, substantially as set forth.

2. The feed mechanism herein described, consisting, of an eccentric mounted upon a vertical shaft and a vibrating lever provided at one end with an eccentric strap to engage with said eccentric, and at the other end formed with a bend or offset, H", in combination with a rough-surface feed-block mounted on a feed bar, K, having a perforation through which the offset II reciprocates, and a sliding fulerum, I, made adjustable to and from the. feedbar, whereby the four motions of the feedblock are all made positive and the length of the stitch is regulated, substantially as set forth.

3. The variable fulcrum herein described, formed of a block made adjustable by means of a slot and screw, and arranged to slide back and forth upon a guide-rod, L, substantially as set forth.

4. In a shuttle sewing-machine of otherwise suitable construction, a feed-bar and a bent feed-lever, ll, having a sliding fulcrum, the vertical shaft B, and eccentric G thereon, as described, in combination with a shuttle-lever of the first order and a grooved cam-wheel, (J, on said shat't B, substantially as set forth.

CHARLES F. HARLOW.

Witnesses:

WM. P. BARKER, A. H. SPENCER.

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