US438690A

US438690A - Sewing-machine

Info

Publication number: US438690A
Authority: US
Publication date: 1890-10-21
Anticipated expiration: 1907-10-21

Description

(No Model.) 3 Sheets-Shet 1.

M. LAOHMAN. SEWING MACHINE.

No. 438,690. Patented ott. 21, 1890.

(No Model.) 3 Sheets-Sheet 2.

M. LAOHMAN. SEWING MACHINE.

No. 438,690. Patented Oct. 21,1890.

111: NORRI! virus (10., movinmm, WASHINGTON, o. c.

' 3 Sheets-Sheet 3.

(N0 ModeL.)

M. LACHMAN.

SEWING MACHINE.

Patented Oct, 21,

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- UNITED STATES PATENT OFFICE.

MORRIS LACHMAN, OF SAN FRANCISCO, CALIFORNIA.

SEWING-MACHINE.

SPECIFICATION formingpart of Letters Patent N0. 438,690, dated October 21, 1890.

Application filed July 8, 1889.. Serial No. 316,738. (No model.)

To all whom it may concern:

Be it known that I, MORRIS LACHMAN, a citizen of the United States, residing at San Francisco, count-y of San Francisco, and State of California, have invented certain new and useful Improvements in Sewingdl/Iachines, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to that class of sewing-machines which use but a single thread, forming the seam by what is known as the chain-stitch, and in which the loop of the chain-stitch is formed by means of a loose rotating looper which passes through the loop and retains it in a distended condition until it has been pierced by the needle upon its next descent.

In operating the loopers of this class heretofore proposed it has been found that when the looper is driven at high speed the loop held by the looper as it is being opened out to receive the point of the descending needle is liable to escape too quickly from the forked tail of the looper,'and so fail to be pierced by the descending needle, thereby causing a stitch to be dropped. It has also been found in operating these loopers as heretofore proposed at high speed that the loop released from the forked tail of the looper is liable to be caught by the nose of the looper at the same time that the looper takes the next loop from the needle, and when this occurs it results in a breaking of the thread and hinder: ance to the operation of the machine. These difficulties have prevented the attainment of so high a degree of speed in this class of machines as is desirable and as otherwise wouldbe practicable.

It is the object of the present invention, among other things, to overcome these defects in the operation of the machine by providing means for positively holding the loop upon the forked tail of the looper until it has been pierced by the needle, and in providing means for positively removing the loop delivered from the tail of the looper out of the path of the nose of the looper, so as to prevent the possibility of its being taken thereby.

The improvements constituting the present invention may be readily applied by slight modifications to several of the sewing-machines now on the market; but they are more particularly applicable to the well-known Wheeler & WVilsonjand they are therefore illustrated in the present case as applied to a machine of that type.

My improved looper may be provided, also, with a bridge-piece so arranged that the amount of thread drawn through the needle by the looper will conform exactly or approximately to the amount drawn through the needle by the hook of the Wheeler 85 WVilson machine. By this means it becomes possible without any change whatever in the machine, except the provision of the driver with a de: flector, which will be hereinafter referred to, to substitute the loose looper for the loose revolving hook and bobbin holder, and thus convert the Wheeler 85 Wilson machine from a double-threaded to a single-threaded machine, and vice versa, at pleasure.

As the full understanding of the unprovements constituting this invention can be readily gained only by an illustration and a detailed description of an embodiment of the same, all further preliminary description will be omitted and a detailed description given, reference being had to the accompanying drawings, in which Figure 1 is a front view of the looper detached from the other parts of the machine. Fig. 2 is an edge view of the same. Fig. 3 is a side View of the driver of a Wheeler & Wilson machine, provided with the deflector before referred to. Figs. 3 3 and 3 illustrate the construction and operation of the looper-retaining ring and the device carried by the ring, which operates to retain the loop upon the forked tail of the looper until after it has been pierced by the needle, Fig. 3 being an edge View of the ring detached, and Figs. 3 and 3 being front and edge views, respectively, of the ring in position upon the race. Fig. 4 is an end view of the well-known Wheeler & WVilson sewing-machine equipped with a looper embodying the present invention. Figs. 5, 6, and 7 are diagrams showing the looper, driver, and needle in different positions which they take during the formation of a stitch. Figs. 8 and 9 are views similar to Figs. 1 and 2, showing the bridge-piece omitted from the looper, which will be the case when the looper is not intended to be used interchangeably with a hook and bobhi carrier.

Referring to said drawings, it is to be understood that A is the faceplate of the head of the machine; B, the needle-bar; B, the needle; C, the presser-bar, with foot 0; D, the table, with throat-plate D; E, the looper, which revolves in a vertical plane in the race F; F, the looper-retaining ring, which is secured to the race by screws F and G the driver mounted 011 the end of a shaft placed longitudinally of the machine under the table and suitably driven. II is the ordinary lVheeler d: \Vilson take-up, and H the tension device, all of which parts above mentioned, with the exception of the looper and certain additions to the driver and looper-retaining ring, are of the ordinary \Vheeler dz \Vilson construction.

The looper E is of annular form, and is provided with shoulders 2 3 to receive the driver in substantially the same manner that the hook receives the driver inthe XVheeler db Wilson machine. The nose 4 of the looperis pointed and of substantially the common form to take the loop from the needle as the looper.

is revolved by the driver. The tail of the looper is forked, the outer prong 5 terminating at some distance from the nose, while the inner prong 6 is extended to a point slightly beyond the nose 4. The prong 6 will preferably be parallel with the inner face of the looper, as indicated by full lines in Fig. 2; but it may project or curve inward, as indicated by dotted lines in said figure, for a purpose which will be hereinafter explained.

The driver G is of the ordinary \Vheeler dc YVilson form, it being provided with shoulders 7 8, which act against the shoulders 2 3 of the looper.

It has been stated that in operating this class of machines at high speeds difficulty has been encountered owing to the tendency of the loop to slip ofi the forked tail of the looper before being pierced by the needle. If this tendency is overcome by increasing the length of the prongs of the tail of the looper, so as to retain the loop for a longer time relatively to the movements of the needle, then difficulty has been experienced in preventing the loop which has just been pierced by the needle from being taken by the nose of the looper, thus deranging the operation of the machine. To avoid the first difficulty I have made the outer prong of the looper comparatively short, as before explained, so that the loop will be retained in a distended condition upon the fork but a short time; and to prevent the loop from slipping off the short prong of the fork before it has been pierced by the needle I provide a retaining-plate 9, which is supported upon the looper-retaining ring F, or in any other convenient manner, and projects inward so as to overlap and lie in close proximity to the short prong of the tail of the looper as the latter passes beneath it. By this means the forward edge of the retaining-plate 9, which is inclined, as will be observed, acts to positively retain the loop upon the fork of the looper in a distended condition until the end of the short prong of thefork has passed the forward end of the plate, and the parts of the looper are so timed with relation to the needle that this does not take place until the needle has descended sufficiently to pierce the loop. Even when the fork of the looper is constructed in this manner and is provided with the cooperating retaining-plate there is liability in rapid operation that the loop delivered from the tail of the looper will remain in position to be caught by the advancing nose. To partially guard against this the inner prong 6 of the looper is continued so as to extend slightly past the nose 4, thereby holding the loop to one side of the path of the nose. If the prong 6 is curved inward, as indicated by dotted lines in Fig. 2, it is alone sufficient in many cases to prevent theloop delivered from the looper from being caught by the nose of the looper; but in most cases it is preferable to supplement the extended inner prong of the looper with a deflector G, projecting from and carried by the driverand so located as to occupy a slightly oblique position between the nose and the longer prong of the tail of the looper, extending forward beyond the nose considerably, as indicated in the drawings. By this means the loop which is held by the longer prong of the tail of the looper is, as it is approached by the nose of the looper, acted upon by the deflector so as to be raised and move laterally out of the path of the nose of the looper, so as to permit the latter to pass without danger of passing through it. It will thus be seen that the loop upon the looper is under positive control until the next loop has been taken by the nose of the looper.

A very brief statement of the operation of the mechanism thus far described will be sufficient.

Referring to Figs. 5, 3 and 3, the parts are seen in the position they occupy as the needle is descending and just as it has pierced the loop held in a distended condition upon the forked tail of the looper by the retainingplate 9. Directly after the needle has pierced the loop the rear end of the short prong of the tail of the looper passes beyond the plate and the loop at once slips off said prong, but is still retained by the longer prong, as shown in Fig. 6. Just before the nose of the looper arrives at the needle and in position to take the needle'loop the deflector G acts upon the loop to move it inward and upward and hold it out of the path of the nose, as shown in said Fig. 6, so as to prevent all danger of its being taken thereby, and immediately after the needle-loop has been taken by the nose of the looper the previous loop passes off the longer prong of the tail of the looper, and so the operation is repeated.

here the invention is applied to a n1achine, such, for example, as the WVhceler &:

Wilson type, as shown in the present case, and it is desired that the machine should be used interchangeablyas a lock-stitch or chainstitch machine, it is desirable that the looper should be provided with a bridge E, which, as shown in Fig. 1, has an operating surface, preferably made convex in its plane of rotation, for the purpose of drawing more thread through the needle, and, as shown in Fig. 2, is arched over the face of the looper to allow the needle as it descends between the forks of the tail to pass between the bridge and the plane of the looper, as shown in Fig. 6, thus avoiding any interference with the movement of the needle. The arch of the bridge serves also to increase the amount of thread drawn through the needle, and it is evident that the extent to which the bridge is arched may be varied in the construction of thelooper in accordance with the amount of thread to be so drawn. This bridged looper will act, as shown in Fig.7, to draw through the needle an amount of thread equal or substantially equal to the amount drawn through the needle by the hook or other similar device when the machine is used in forming the lock-stitch. This is desirable, as by this means the machine can be used interchangeably without any necessity of changing or adjusting the take-up mechanism. WVhere, however, the invention is applied to a machine which it is not desired to use interchangeably as a lock-stitch or chain-stitch machine, the bridge will preferably be omitted, as indicated in Figs. 8 and 9, the looper in other respects remaining the same as already described. By the omission of the bridge the amount of thread drawn through the needle by the looper is reduced to the minimum, and as a consequence the take-up mechanism can be correspondingly modified, which is highly advantageous.

What I claim is 1. The combination, with the. needle and the rotating looper having the forked tail, of the stationary retaining-plate projecting over the path of the tail of the looper to retain the loop thereon, substantially as described.

2. The combination, with the needle and the rotating looper having a forked tail consisting of a long prong and a short prong, of the stationary retainingplate projecting over the path of the tail of the looper to retain the loop thereon, substantially as described.

3. The loose rotating looper havinga forked tail, one prong of which terminates in advance of the nose of the looper and the other prong of which is extended past the nose of the looper, substantially as described.

4. The combination, with the needle and the loose rotating looper, of the driver for the looper and the deflector carried by the driver and arranged just in advance of the nose of the looper and acting to remove the previous loop from the path of said nose, substantially as described.

5. The combination, with the needle, of the loose rotating looper havinga forked tail, one prong of which terminates in advance of the nose of the looper and the other prong of which is extended past the nose of the looper, and the deflector arranged just in advance of the nose of the looper and acting to remove the previous loop from the path of said nose, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

GEORGE I-I. Borrs, J. J. KENNEDY.