US1335374A - Multiple-needle chain-stitching machine - Google Patents

Description

G. S. GA-TCHELL.

v MULTIPLE NEEDLE CHAIN STITCHING MACHINE. APPLICATION man 020.4, 1916- 1,335,374. Patented Mar. 30, 1920.

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G. S. GATCHELL.

MULTIPLE NEEDLE CHMN STITCHING MACHINE;

WITNESS Mex-JAM APPLICATION men b:c.'4. 1.91s.

Patented Mar. 30, 1920 2 shins-sneer 2.

UNITED STATES PATENT onnion.

GEORGE S. GATCI-IELL, OF ROSELLE PARK, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

MULTIPLE-NEEDLE CHAIN-STITCHING MACHINE.

Specification of Letters Patent.

Patented Mar. 30, 1920.

Application filed December 4 1916. Serial No. 135,053.

To all whom it may concern:

Be it known that I, GEORGE S. GA'roHnLL, a citizen of the United States, residing at Roselle Park, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Multiple- Needle Chain-Stitching Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to sewing machines and particularly to an auxiliary for msuring the perfect formation of double chainstitches.

In some machines having a plurality of needles and a single looper cooperating therewith the latter in backing out of the needle-loop assumes an upward inclination which causes the needle-loops to slide or tend to slide off the looper. If the needleloops in such a case are not restrained they will be displaced sufiioiently to be entered by the adjacent needles and the resultant seam will be imperfect. in the present invention by providing'fingers which enter between the needles and restrain the needle-loops from slipping toward the point of the looper.

The looper in backing out of the needleloops leaves a loop of thread through said needleloops and around the needles which have punctured the fabric in making ready for the next stitch. In taking up the needleloops being shed, one of the limbs of the looper loop is drawn into a zigzag or irregular form necessarily of greater length than before the taking up occurred. In multiple needle machines the increased length of looper-thread required has heretofore been drawn entirely from one side of the seam necessarily resulting in additional friction on the looper-thread and imposing in consequence a greater strain on the needle-loops An imperfectly set stitch being drawn up. or a broken thread frequently results. It is an aim of this invention to provide a means, such as a finger, for engaging the limb of looper-thread between the work and the eye of the looper ,to pull off looper-thread from the supply in advance of the taking up of the needle-loops, especially the needle-loop first shed by the looper, in order to furnish looper-thread from both sides of the seam during the taking up of the needle-loops.

My invention consists further in certain details of construction, which will appear This is prevented from the description of an embodiment thereof illustrated in the accompanying drawings, in which Figure 1 is a sectional side elevation of the machlne. Fig. 2 is a plan of the work-supporting arm with parts i removed and other parts sectioned to show the trains of driving mechanism. Fig. 3 is a bottom plan view of the throat-plate with rear of the needles looking toward the free end of the arm showing the conditions of the looper-thread and needle-loops before (Flg-S) and after (Fig. 6) the looper has about to be shed (Fig. 7) by the looper. Fig. 9 is a section similar to Fig. 8 of a modification of my invention. Fig. 10 is a bottom plan view of a seam made with this type of a machine.

In the embodiment of the invention illustially the same lengths with eyes 6 spacedv at different distances from their points. The

needles are carried by a needle-clamp 7 on a needle-bar 8 which is actuated by any suitable mechanism of which. the prior art affords a great variety.

In tubular arm machines where the available surface at the end of the arm is small the looper is usually mounted for movement about an axis from -}g to 1-} inches from the blade of the looper. The looper illustrated is of such short radius type. It comprises a blade 9 provided with an eye 10 in its beak and a thread passage 11 in its heel. WVhen the beak of the looper is di rectly above its axis of rotation the looper occupies an upwardly inclined position with its beak close to the throat-plate as indicated in Fig. 7.

At the free end of the tubular arm is a throat-plate 12 having a plurality of stationary fingers 12 defining needle-holes started back and when the needle-loops are p 12". On the lower side of the throat-plate is mounted for movement, substantially in a plane intermediate the back of the looper and the lower face of the plate, a plurality of movable fingers 13 of progressively greater length from the beak to the heel of the looper. As shown, but not necessarily, these fingers are formed integral with a bent plate 14 provided with a slot 15 for adjustably connecting it by a screw 16 threaded in an arm 17 pivoted at 18 to a slide 19 in which is threaded a stud 21 passin freely through a hole 22 in the arm and afi ording, in connection with a reach strip 23 secured to an arm 24 fast on a rod 25 which is reciprocated in any suitable manner, means for actuating the fingers 13. In the illustrated construction the rod 25 is conveniently reciprocated from an eccentric 26 on the thread-controlling cam-shaft 27, .geared at 28 with the main-shaft 29 of the machine,

through an eccentric strap 30 loosely pinned at 31 to a collar 32 fixedly connected to the rod 25, the strap of course encirclin the eccentric on the cam-shaft. Throug the stud 21 the slide 19 is therefore reciprocated and with it the arm 17 to carry the fingers into engagement with the needle-loops, in the present embodiment, in the direction of feed.

As the arm 17 carrying the fingers 13 across the back of the looper into engagement with the needle-loops reaches the forward end of its stroke it is given a movement laterally or sidewise to shift the fingers toward the heel of the looper in which movement they cross from one side to the other of the needle-holes 12" in the throatplate 12. lVhen the arm 17 moving away from the looper to disengage the fingers from the needle-loops reaches the backward end of its stroke, it is given a lateral movement in the opposite direction to that above mentioned in order to position the fingers for their entrance on the proper side of the needles. In this case the proper side is to the right when looking down on the top of the throat plate from the end of the arm.

For giving the above mentioned lateral motions to the fingers any suitable mechanism can be used. In one form an arrangement of 'bevels or stationary cam-surfaces has been used. The arm 17 is provided with oppositely extending projections 40 and 40 on its sides which projections are beveled at their rear and forward edges respectively as indicated at 41 and 41 to lift the forward extremities of the pivoted fingers 42 and 4.2 which are provided with cooperating cam-noses 43 and 43. The fingers 42 and 42 are pivoted at 44 and 44 to the side bars 45 and 45 below the ribs 46 and 46 which, as shown in Fig. 4, define with the throat-plate 12 a guide-way in which the slide '19 reciprocates. Screws 47 secure the side bars to the throat-plate. A leafspring 48 holds each pivoted finger yieldingly against the rib on each of the sidebars. At their forward ends each side-bar is equipped with a fin 49 on which is mounted a deflecting cam 50 or 50 respec tively adjustable by means of the elongated slots 51 for receiving the screws 52. With the deflecting cams 50 and 50 cooperate the oppositely faced inclined cams 53 and 53 on the forward end of the arm 17.

In Fig. 3 of the drawing the swinging arm 17 is shown just after it has been swung or deflected to carry the fingers 13 across the needle-holes and ready to be retracted longitudinally of the fingers. The pivoted fingers 42 and 42 are both resting against the ribs 46 and 46 but finger 42 is about to be lifted by the projection 40 when the arm is retracted in a direction substantially parallel to that of the edge 54 of the sta tionary deflecting cam 50 which direction it is constrained to keep because the projection 40 on the opposite side of the arm abuts against the nose 43 of the finger 42. IV hen the arm 17 has been retracted and the inclined faces of the deflecting cams 50 and brought into contact, nose 43 no longer abuts projection 40 and the arm is free to be deflected by the said inclined faces. And in this lateral movement of the fingers when they are in retracted position the pivoted finger drops down against the rib 46 and the arm is ready to start forward to carry the fingers into engagement with the needle-loops on the opposite side of the needle-holes. In the forward movement of the arm it is constrained to move with the side face of the projection 40 abutting the side-wall of the nose 43 of the pivoted finger 42. During this movement nose 43 of the other finger 42 is lifted up by the wedge-shaped edge of the projection 40' on which it rides until the deflecting cams 50 and 53 engage and shift the front end of the arm laterally to the position shown in Fig. 3 from which the foregoing description of the operation started.

Each of the fingers 13, which are given four motions in this manner, is in the machine illustrated only long enough to engage one limb of a needle-loop but obvi ously could be made longer or shorter if desired.

When the looper being withdrawn from the needle-loops it assumes an inclination as shown in Fig. 7, such that the needleloops slide toward the end of the looper, despite the factthat the looper in retraction tends to drag the needle-loops with it. To hold the needle-loops back on the looper so that they will not be entered by the needles and so that each needle will descend in its proper triangle of the four formed by the blade of the looper, the several needle loops, and the limb of the looper-thread leading to the work from the eye of the looper, the fingers pass to the side of the needles and sweep across the needle-holes at the proper time in a direction toward the heel of the looper. The fingers are timed to enter between the needle-loops slightly before the needles complete their upward movement. The needles complete their upstroke and start down as the looper starts back and at about this time the fingers carried by the arm are swung quickly across the needle-holes thus crowding the needle-loops toward the heel of the looper and counteracting their tendency to slide off the beak of the looper.

It will be noticed from Fig. 8 of the drawing that the fingers lie in a plane inclined upwardly toward the throat-plate and by inspection of Fig. 3 together with Fig. 8 that the longest finger is nearest the heel of the looper. By this arrangement it is found that the work-limb of the looper-loop, that is, the limb a Fig. 10 of looper-thread leadin from the eye of the looper to the previ ous stitch is engaged by the long finger which is relatively close to the throat-plate. lVhen the long finger is given a lateral movement toward the heel of the looper, thread will be pulled back through the eye of the looper from the supply, thereby furnishing looper-thread from both sides of the seam in the subsequent drawing up of the needle-loops by the descending needles. See dotted lines Fig. 8.

The fingers 13, as shown, lie in a plane slightly inclined to the throat-plate but it is to be understood that the invention is not limited to this specific arrangement as the fingers may be arranged in various ways so long as they lie close to the back of the looper without interfering with its operation. An arrangement which has also been found satisfactory is shown in the modification, Feb. 9, in which it will be noted the long finger indicated at 60 has been bent up above the plane of the other fingers so as to insure engagement with the looper-thread to efit'ect a pulling off from the supply, such as occurred in the preferred form of my invention, as indicated in Fig. 8 in dotted lines, while obtaining substantially a proper control of all of the needle-loops.

And it is obvious that while I described the invention as used in combination with a short radius looper, the broad principles could be applied to a machine with a long radius looper. the retracting movements of which usually cause the needle-loops to assume an inclination in the opposite direction to that previously described due to the fact that the needle-loops are dragged back with the looper. In such case the fingers 13 could be given a lateral movement across the needle-holes in a direction opposite to that mentioned in the foregoing description of the preferred construction. The broad principle of this phase of my invention, as I understand it at this time, is to locate the needle-loops so that they will be compelled to occupy their correct position in order to insure as far as possible the formation of a perfect seam.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine having work-feeding mechanism including a feed-dog and stitch-forming mechanism including a plurality of spaced needles and a cooperating looper, in combination, a throat-plate having one or more stationary stitch fingers thereon, movable fingers operatively supported below the stationary fingers for restraining during certain times movement of needle-loops on the looper, and means for shifting said movable fingers laterally of the looper and in the direction of feed to engage and in the opposite direction to release the needle-loops.

2. In a double chain-stitch sewing machine having a plurality of needles, and a thread-carrying looper, a throat-plate, fingers for engaging the needle-loops on the looper, and means for imparting four-motions to said fingers substantially in a plane intermediate the looper and the throat-plate.

3. In a double chain-stitch sewing ma chine having a plurality of needles and a thread-carrying looper, fingers for engaging the needle-loops on the looper, said fingers being progressively longer from the beak to the heel of the looper whereby successive shedding of the needle-loops is insured, and means for moving said fingers toward and from said looper.

4. In a two-thread chain-stitch machine having a plurality of needles and a sidewise and endwise movable looper cooperating therewith to form stitches, a finger for engaging the looper-thread leading from the looper to the previous stitch, and means for relatively moving said looper and finger to pull the thread from the supply whereby, in drawing up the needle-loops, looper-thread will be supplied to its irregular limb from both sides of the seam.

5. In a two-thread chain-stitch machine having a plurality of needles and a sidewise and endwise movable looper cooperating therewith to form stitches. a finger for engaging the looper-thread leading from the looper to the previous stitch and means for relatively moving said looper and finger to pull upon the looper-thread between the looper and the previous stitch before the needle-loops are drawnup by the descending needles.

(3. In a two-thread chain-stitch machine having a plurality of needles and a sidewise and endwise movable looper cooperating

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