US418716A - Charles f - Google Patents

Description

C. P. HARLOW.

, SEWING MACHINE.

pro/418,716.

Patented Jan. "7, 1890.

' V UNITED STATES PATENT OFFICE.

CHARLES F. HARLOW, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE SEAM MACHINE COMPANY, OF SAME PLACE.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 418,716, dated January '7, 1890. Application filed November '7, 1888. Serial No. 290,196. (No model.)

- To all whom it may concern.-

Be it. known that 1, CHARLES F. HARLOW, of Boston, county of Suffolk, and State of -Massachusetts, have invented an Improveparts.

. My invention is embodied in a sewing-inachine of that class in which an enchained or .looped stitch is made by means of an eyepointed needle and loop-holder, the machine being. adapted for operating with waxed thread as well as with dry thread.

The invention relates, mainly, to the loopholder or device that engages the loop of thread extending from the fabric to the eye of the needle and holds the same while the needle is being withdrawn and again passed through the fabric or material being sewed and into the loop thus held by the loopholder, which latter is then withdrawn, leaving the loop previously held by it around the shank of the needle, and. is then again carried forward to engage the new loop extending from the material to, the eye of the needle below the 100p. .preyiously held by the loop-holder. e

In chain-stitch sewing-machines having a vibrating or reciprocating loop holderas heretofore made, so far as known'to me, the forward movement of the loop-holder into the new loop isin the same path as the rearward movement out from the previously-held loop,

and in such construction and mode of operation there is danger that the loop-holder in coming forward to engage the new loop will also catch again in the old loop and prevent it from being drawn up properly to make the stitch.

The main object of the present invention is to overcome this objection; and the invention consists, mainly, in means for operating the loop-holder in such manner that it advances to engage the new loop in a different path from that which it followed in leaving the old loop, the said loop-holder having, in

addition to its vibrating or reciprocating movement into and outfrom the loop, also a lateral motion, which takes place Just after it leaves the old loop and before it enters the I it leaves the old loop around the shank of the needle. In the construction shown inthis instance the loop-holder is a curved hook or finger, and is pivoted on an axis about which it oscillates in its vibratory endwise movement toward and from the said needle, and the said pivot is itself supported on a slidebar having a reciprocating movement by which the entire loop-holder is moved bodily in its plane of vibratory or oscillating movement.

The loop-holder occupies but little space in a direction at right angles to the seam in the material being sewed, and a number of said loop-holders may be mounted side by side on a single pivoted carrying-block, so that all will partake of the same movement, each cooperating with a corresponding needle, anumber of which needles may be carried by a single needle-bar forthe purpose of sewing two or more parallel seams simultaneously.

Figure 1 is a front elevation showing the main operative parts of a sewing-machine 'embodying this'invention; Fig. 2,a similar elevation with the feed mechanism removed in order to show more clearly the loopholder and its operating mechanism; Figs. 3

to 8, inclusive, details showing the relative 'position of the needle at different points in the operation of making the stitch; and Figs. 9 and 10, modifications to be referred to" The invention is embodied in a machine having a shaft a above the plate or work sup- I 7 port I), and a shaft 0 below the said'wo'rksupport, the said shafts aand c-being connected to rotate simultaneously andoperate the stitch-forming devices above and below the fabric, respectively. The parts operated:

or more eye-pointed needles 6 in the usualmanner, forcing the needle down and carrying its pointbelow the fabric and then withdrawing the needle until its point is some distance above the fabric at each rotation of the said shaft. The pre'sser-foot f and feeding devices g may also be of any suitahle construction, the latter being shown as a foot formed at the end of a bar g connected at its lower end with a crank or eccentric on the shaft 0, the said bar workinginaguide g, which is adjustable along the bar, the upper end of which thus has a lateral and vertical movement produced by the rotary movement of its lower end, and the amount of lateral movement depending on the position of its guide g which is adjustable up and down the bar for the purpose of shortenin g or lengthening the feed, as will be readily understood.

The loop.- holder It consists of a curved hook or finger, the end of which is made very thin, and passes, close by the side of the needle when thelatter is projected downward below the under surface of the fabric, while the shank of the said loop-holder is thicker or wider than its point, and thus spreads the loop open when around the shank, so that the needle will pass through the loop held on the loop-holder when the needle descends, while the loop-holder is moving backward from its forward position, as shown in Figs. 4, 5, and 6, The said loop-holder h is supported on a block i, pivoted at upon the slide-bar it, working in its guide 70 upon the frame-work of the sewing-machine, and the said looperblock is oscillated upon its pivot i so as to throw the loop -holding finger forward toward the needle and back from the needle by means of a pitman m, connected with the said block eat one side of its pivot, and also connected with a slide-bar 'It, that works in a guide-groove in the slide-bar k, the said slidebar at being provided with a cam roller or projection 12 working in a cam-groove 0 in a cam-disk p on the shaft 0. Assuming that the slide-bar 76, were stationary, or that the pivot i were stationary on the frame-work of the machine, the cam-groove 0, in connection with the slide-bar n and pitman m, would give the loop-holder finger h an oscillating movement at each rotation of the main shaft by which its point would be thrown forward into the loop of thread extending from the eye of the needle to the fabric just as the needle was rising, and thus tending to open the said loop, which would remain held by the loop-holder until the needle again descended and passed through the loop thus held by the loop-holder, which would, immediately after the needle had passed through the loop, be vibrated back out from said loop and leave it around the shank of the needle, and would then be vibrated forward again just as the needle began to rise, so as to engage the new loop at the eye of the needle, as before described.

The cam-groove 0 and intermediate devices between it and the looper do, in fact, give it substantially the movements just described; but in addition to such oscillating or endwise movement of the loop-holder it around its pivot 1' the said pivot itself is also given a reciprocating movement by means of a cam proj eetion or roller working in a camgroove 0 being so shaped and arranged with relation to the groove 0, which vibrates the loop-holder, that the said pivot 1Z descends in the interval between the backward and forward movements of the loop-holder, so that its forward movement is made at a lower level than its backward movement, or, in other words, it enters the new loop, as shown in Fig. 8, below the point at which it left the old loop, as shown in Fig. 6. The cam 0 then causes the pivot 2' to rise gradually while the loopholder is coming to and remains in its forward position, during which time the needle is being withdrawn from the fabric and the last loop is being drawn up, so that when the needle again enters the fabric the loopholder will be in its higher position, and the loop, which is at all times held tightly by it, will be left by it around the shank of the needle at such point that when the loop-holder again advances at the lower level it isimpos sible for it to engage the loop previously cast off from it, as might take place if the loopholder advanced and receded in the same path.

If desired, the looper-block 11 :night carry a number of different looper-hooks, as shown in Fig. 9, co-operating with a number of different needles to form several scams or lines of stitching simultaneously, and when two such seams are to be placed very near together the bop-holding fingers will be made right and left handed with relation to one another, as shown in Fig. 9, and their thin point-s will be adjacent to one another, so as to require but very small space between theneedles.

The relative positions of the needle and the loop-holder in the process of forming the.

stitch are illustrated in Figs? to 8,inclusive.

The substantially coneentric portions of the cam-grooves in the cam-plate p, between the radial lines 2 and 3 thereof, (see Fig. 1,) in passing the cam-rollers retain the pivot of the loop-holder in its highest position and the loop-holding finger in its forward position, as shown in Fig. 3, during the greater part of the rise and descent of the needle while its point is above the fabric. In the latter part of the descent of the needle the portion of the cam-groove 0 between the lines 3 and 4 throws the loop-holder back to the position shown in Fig. 4 just as the point of the needle passes through and below the fabric, and thus enters within the loop, as will be understood from Figs. 4: and 5, the latter showing a plan view of the loop-holding finger and section of the needle. During this part of the movement the cam-groove 0 has not changed the position of the pivot t. Then while the portion of the cams between the lines 4: and 6 passes over the cam-rollers the slide-bar 7c and pivot 2' will be drawn down; but the pitman we will be drawn down much more rapidly, so that the loop-holder will continue to be oscillated back from the position shown in Fig/Ito the position shown in Fig. 6 and then to that shown in Fig. 7,

' while at the same time the pivot 2' will have if any, change in the position of the looperpivot '5 such movement projecting the point of the finger into the loop of thread which is then being formed by the beginning of the rise of the needle, as will be understood from Fig. 8, after which the portion of the camgrooves between the lines 8 and 2 will cause the pivot 2' to rise, but will cause the pitman m to rise more rapidly, so that the loop-holder will have a bodily lateral upward movement simultaneous with its endwise forward vibrating or oscillating movement, by which it is again brought to the position shown in Fig. 8.

It is obvious that the mechanical construction of the loop-holder and its operating devices may be widely varied while retaining substantially the same mode of operation, and various other devices might be substituted for the specific ones shown for giving the loop-holder the movements described with relation to the needle.

The pivott' practically constitutesa guide which determines the path of the reciprocating or vibrating movement of theloop-holder, and the said guide, instead of being stationary, as heretofore practiced, is itself made movable, so that the path of movement of the loop-holder is shifted with relation to the frame-work of the machine during the said movements of the loop-holder on its guide.

Fig. IO represents a mechanical modification by which a similar result is attained. In this case the cam o for the slide-bar k is dispensed with, andthe said slide-bar has a slight frictional resistance to its movement, and the pi votal movement of the looperblock t' thereon is limited by suitable stops t By this construction a single cam groove that acts on the pitman or equivalent connection with the looper-block, gives the latter both of its movements, first rocking the same forward on its pivot until such rocking movement is arrested by the stop, when the further upward movement of the pitman will cause an endwise upward movement of the slide-bar, which will remain in its uppermost position until the loop-holder is moved back until arrested by the stop, after which a further downward movement of the pitman will cause the slide-bar to move downward, so that the endwise and lateral movements of the loop-holder will alternate with one another.

It is considered preferable to move both the looper-block and its guide separately and positively, as herein shown, and so that the lateral movement may in part accompany the endwise movement instead of having one movement wholly finished before the other begins.

I claim 7 1. In a sewing-machine, the combination of a reciprocating eye-pointed needle and.

work-support with a vibrating loop-holding finger at the opposite side of said work-support from that at which the needle enters the work, said loop-holding finger having a thin point portion and a wider shank portion, a supporting-guide on which said loop-holding finger vibrates, said guide being movable substantially in line with the needle, and two cam-surfaces, one co-operating with and vibrating the said loop-holding finger and the other co-operating with and reciprocating its supporting-guide, substantially as described.

2. The combination of a reciprocating eyepointed needle and work-support with the loop-holding finger at the opposite side' of said work-support from that at which the needle enters the work, said loop-holding finger having a thin point portion andwider shank portion, a pivoted carrying-block for said loop-holding finger, and a reciprocating slide-bar upon which said block is pivoted, substantially as described.

3. The combination of areciprocating needle-barand two or more eye-pointed needles carried thereby with a pivoted looper-block and two or more loop-holding fingers supported thereon, each of said fingers having a thin point portion substantially in line with one side of the shank portion, said point portions on two adjacent fingers being at opposite sides of the shank portions, respectively, substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CHARLES F. HARLOW.

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