US556715A - Loop-retainer for sewing-machines - Google Patents

Description

(No Model.)

L.MUTHER.

LOOP RETAINER FOR SEWING MACHINES.

.No. 556,715. Patented Mar. 17, 1896.

ANDREW EGHANAIQ]. FHOYOU'MEWKSHINGTONJ C.

UNITED STATES PATENT EEicE,

LORENZ MUTHER, OF OAK PARK, ASSIGNOR TO THE UNION SPECIAL SElVING MACHINE COMPANY, OF CIIIUAGO, ILLINOIS.

LOOP-RETAINER FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 556,715, dated March 17, 1896.

Application filed July 12, 1894. Serial No. 617,345. (No model.)

To all whom it may concern.-

3e it known that I, LORENZ MUTHER, a citizen of the United States, residing at Oak Park, in the county of Cook, State of Illinois, have invented certain newand useful Imp rovements in Sewing-Machines, of which the following is a description, reference being had to the accompanying drawings and to the letters of reference marked thereon.

My invention relates to an improvement in sewing-machines of the general class illustrated in Patent No. 3%,493, dated June 29, 1886.

It has heretofore been proposed in ma chines of this character to provide the looper near its heel with a notch on the grooved inner edge to leave a shoulder to catch and hold the loop of the needle-thread as the looper moves backward, thus drawing the loops of needle-thread out of the way of the needles as they again descend through the material to enter the loop of the thread carried by the looper. To prevent the loops of needle-thread held upon the looper as the latter is retracted or drawn backward, or out of the loops of said needle-thread, from being drawn forward by the strain of the thread so as to get in the path of the descending needles, which are about entering the loop of the looper-thread, it has been proposed to provide the throat-plate at its under side and to one side of the needle-hole with a transverse depression or groove and a finger against which the loops of the needle-thread arrive and bear as the points of the needles descend between the looper and the looper-thread, the outer or free end of said finger substantially holding the said loops until the point of the looper in its backward movement comes to the finger, the outer end of the finger projccting over said depression.

I have found in practice that it the finger does not bear a certain relation to the looper there is liability of skipping stitches, and this necessary relation is destroyed either by deepening the hole for the looper-shank or otherwise setting the looper too low, or by forming the finger a little out of proper shape or allowing it to become sprung. It sometimes happens that the fingers are not made preciscly alike by the workman, and therefore when put on the throat-plate do not project close enough to the edge of the looper and thusleave space suflicient to allow the needleloops to run oiii the looper and to be cut off by the needles orcause stitches to be dropped.

To avoid the above objections the present invention has been made; and it consists in providing means of adjustment for said finger whereby it can always be secured in proper position with respect to the looper, as hereinafter described and claimed.

My invention is illustrated in the accompanying drawings, in which Figure 1 shows a longitudinal section of a portion of a cylinder vamping-machine to which my invention is applied, the looper being shown as just entering the needle-thread loops, the needles moving upward. Fig. 9 is an end View showing the parts while the looper is being retracted and the needles descending to pass between the looper and its thread. Fig. is a detail view of a curved throat-plate, showing the finger, the looper moving backward, and the thread; and Fig. i is a bottom plan view of a flat throat-plate provided with my invention.

In the drawings, A represents a portion of the casing of a cylinder vainping-machine, and B is the throat-plate thereof, the same letter also representing the flat throat-plate shown in Fig. i.

(1 represents the looper having the usual notch forming a shoulder a, behind which in the extreme forward position of the looper the needle-threads slip and by which they are drawn backward as the looper is retracted.

The ordinary looper-guard finger l) is provided as well as the needle-guard c.

D is the needle-bar, herein shown as carrying the two needles d.

The throat-plate B has on its side nearest the heel of the looper a shallow transverse groove 6, and a finger f, composed of a piece of wire or other suitable material, is attached to the under side of the throat-plate by the screw g, the point of said finger lying close to one of the needles and extending partially over the depressed portion to leave a space between the under side of the throat-plate and point of the finger. This finger is preferably made of wire or spring metal; but it IOO sometimes happens that in replacing the parts the finger will become sprung, so that when secured to the throat-plate it will not rest in proper relation to the looper, or it may be that the fingers may not be all alike or that the looper on one machine maybe set a little lower than on another, in which case the ordinary finger would not perform the desired function.

To enable the fingers to be interchangeable to adapt them to machines even after they have been sprung and to allow for inequalities in the setting of the looper, I provide a set-screw h, which passes through the throatplate and bears upon the upper side of the wire, and by tightening or loosening this screw the finger is adjusted to bring it into proper relation with the looper. The forward end of the finger is out out on its under side, as at i, to allow of the backward movement of the looper without danger of it striking the finger.

The operation will be easily understood from the foregoing description. In the for ward movement of the looper the needles descend and the looper passes through the loops of the needle-threads and beyond the end of the finger. lVhen the limit of its forward movement has been reached, the loops of the needle-threads now around the looper slip into the notch thereon, and as the looper takes its sidewise movement and goes backward the shoulder draws the threads aside until the looper has been retracted a portion of its distance, when the loops of the needle-thread slip from the shoulder and move toward the point of the looper. \Vhen they reach the point of the finger, they are passed over it and held on it by the looper and between the finger and the under side of the throatplate, while the needles descend at the rear side of the looper and between it and its thread. Then the looper reaches a point at or near the limit of its backward movement, it releases the need le-loops, which are then drawn up into the goods over said finger.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is

A throat-plate provided with a loopretaining spring-finger, secured rigidly to the throatplate, and a set-screw passing through the throat-plate and bearing on said finger whereby the same is vertically adjustable, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

LORENZ MUJIIER. \Vitnesses:

CHESTER MCNEIL, lllARTIN MCNEIL.

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