US236788A - Sewing-machine - Google Patents

Description

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L. H. DAVIS.

ASewing," Machine.

Patented Jan. 18,1881.

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L. H. DAVIS. Sewing Machine.

No. 236,788. Patented Jan. 18,1881.

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ifa/ f [n2/afzien UNITED STATES RATENT.- OFFICE.

LEVIS H. DAVIS, OF GHES'IER, PENNSYLVANIA.

SPECIFICATION forming part of Letters Patent No. 236,788, dated January 18, 1881.

d Application filed J une 18, 1880. (No model.)

To all whom it may concern Be itlrno wn that LLEVIS H. DAVIS, a citizen of the United States, residing at West Chester, Chester county, Pennsylvania, have invented new and useful Improvements in Sewing-Machines, of Awhich the followingis a specification. A

This invention relates to that class of sewing-machines in which `the movement of a vibratory shuttle-lever is derived through an oscillating lever from a driving-shaft journaled in the goose-neck, and which actuates the needle-bar. Its objects are to simplify the connection between the shuttle-lever and the oscillating lever which drives it; to simplify the feed mechanism; to provide a take-up which is simple in construction and prompt to act and accommodate itself to the tension of the needlethread; to providel a simple and reliable tension device for the needle-thread.

In the accompanying drawings, Figure 1 is a vertical longitudinal section through the center of the machine. Fig. 2 is a transverse section ofthe machine on line :1: a: of Fig. 1. Fig. 3 is a front view of the take-up devices. Fig. 4 is a bottom view of the machine. Fig. 5 is a front view of the head of the machine and bed-plate. Fig. 6 is a rear view of the front plate of the head and the lever and spring which actuate the take-up, the lug of the needle-bar which moves the lever being shown in section. Fig. 7 is a detached view of the vibratory lever through which motion is communicated from the driving-shaft to the shuttlc-lever, and showing, also, a section of the crank-bend of the driving-shaft and its friction-roller and the pivot-pin of the lever. Fig. 8 is a similar View of the lever through which motion is communicated to the feed-lever. Fi g. 9 is a top view of the tension-spring. Figs. l0 and 11 are detail views of the take-up mechanism. Fig. 12 is a section on line y y, Fig. fl. Fig. 13 is a section on the line z z, Fig. 4. Fig. 14 is a section on line z' z', Fig. 4. Fig. 15 is a detached bottom perspective View of ther feed-dog carrying-bar. Fig. 16 is a detached view of the cam which operates the lever communicating motion to the feed-lever.

The letter A indicates the drivingshaft arranged through thel goose-neck'B, which is cast .in one piece, flaring at its front to form the head C, and having a screw-threaded opening at its rear end to receive the removable bearing b. Where it opens into the head C the goose-neck has formed in its bore a bearing for the sleeve d, which projects from the center of the rotary disk D, and is removably secured upon the front end of the drivingshaft, forming the front journal thereof. In its rearward portion the driving-shaft has formed a crank-bend, A', upon which lsmoun ted a friction-roller, a, and to the rear of the bend A' there is removably secured upon the shaft a cam-roller, D', having a sleeve, d', which fits in the bearing b and forms the rear journal of the shaft. The bend A', while extending laterally suflciently to give the desired throw, is long and gradual, so that the friction-roller may be freely slipped toits place from the front end of the shaft.

Near the rear end of the driving-shaft is mounted a driving-pulley, E, provided with a sheave, E', and screw-threaded sleeve e, upon which travels a nut, E2, having wings e', by which the nut may be turned to jam it against a fixed shoulder, e2, on the end of the shaft, and force the pulley against the end of the bearing d', thus locking the pulley to the shaft. On releasing the pulley it may run freely and be used to operate the bobbin-winder in the ordinary manner. As such devices are not claimed herein a more particular description is deemed unnecessary.

The letter F designates the oscillating lever, through which motion is transmitted from the driving-shaft to the shuttle-lever Gr, pivoted on a pin, g', projecting downward from the bed-plate and extending forward in the usual manner. At its upper end the oscillating lever F is provided with a cam-slot, F', in which plays the friction-roller a, mounted upon the bend A of the driving-shaft. The pivot-pin f, supported in the walls of the vertical portion B of the goose-neck, passes through a bearing, f formed at about the middle of the lever F, the lower end of which terminates in any adjustable ball, f2, which lits loosely in a circular holeor bearing, g, formed for it in the rear end of the shuttle-lever G. The lower half of the Ioscillating lever F consists of a spring-plate, F2, which is rigid edgewise, but elastic iiatwise, its oiiice being to permit the oscillating lever F to accommodate itself' to the are of movement of the rear end of the IOO shuttle-lever. By this means I am enabled to dispense with the cams and slip-joints which have heretofore been used in connecting the shuttle-lever with its driver in this class of machines.

Instead of making the lower arm of the oscillating motion-transmittin g lever elastic, an d having its lower end passing through a hole in the feed-lever, I may make the rear portion of the shuttle-lever or a hook-lever elastic, and insert its end in a hole in the lower end of the motion-transmittin g lever, which may then be rigid throughout its length.

The shape of the slot F' at the upper end of the lever F is such that when the drivingshaft is turned to the right and the roller has just passed upward around the elbow f 3 of the slot the shuttle will have reached the farthest point in its forward movement and has drawn tight the lower thread. At the same time the needle has ascended to its highest position, and thus both threads are drawn at the same time to complete the stitch. Now, as the shaft continues to revolve,tlle bend A' travels up farther and then down to the elbow f3, throwing the shuttle back rapidly to its rearmost position. At this time the needle has descended to its lowermost position and raised sufcientl y to throw a loop, and the bend of the shaft is passing downward in the slot F',`throwing the shuttle through the loop while the needle remains nearly stationary. Then the needle rises rapidly for a short distance and then slacks somewhat, the shuttle moving slowly as the needle ascends, and both arrive at the extreme points of their movement simultaneously, their motion being reversed at the same instant, and they then operate as before.

The oscillating lever H, which drives the feed-lever I, is also pivoted on the pin f, and inclines upwardly to the right, as shown in Fig. 2. It has a somewhat curved bearing-face, h, which bears against the periphery of the cam D', and its lower end has formed in it a hole, h', which fits over a stud, i, projecting from the curved rear end of the feed-lever. The throw of the cam D' is arranged to cause the lever I to drive forward the feed-dog at proper intervals to feed the cloth forward in connection with the feed-raising devices, which will be presently described.

Near the forward end of the lever I is a lateral projection, 1',which I call the feed-steadier, and which, with the lever, plays in a slot formed in the ilange k of the bed-plate. This steadier and its slot prevent the lever I from turning on its longitudinal axis or wabbling, and cause it to preserve a steady back-andforth motion. The extreme forward end of the lever I extends through a slot, l, formed in the end of a bar, L', which carries the feed-dog L. This bar L' is connected with an arm extendingdownward from the bed-plate by means ofa spiral spring, l', which tends to draw the bar backward and downward. The bar L' has a lip, l2, extending from its lower edge beyond the feed-dog, the under surface of said lip being nished to form a bearing-surface, upon which, at proper intervals, presses the end of an arm, m, to raise the bar L' and feed-dogs, so that the teeth of thedog will take properly into the work. The arm m projects from the forward portion of a rock-shaft, M, journaled in bearings under the bed-plate, and from the rear portion ot said rock-shaft there projects another arm, M', having at its end a laterallyprojecting stud, on which is journaled a friction-roller, m', which bears upon the cam-face of a cross-bar, M2, lixed to the rear portion of the shuttle-lever. This cam-face has an elevated portion, m",which, as the shuttle is moved rearward and the feed-dog forward, passes under and against the roller m', pressing the arm M' upward, rocking the shaft M to throw the arm m upward also, and this arm m, striking the lip l, and thus raising the bar L' and the feed-dog, so that it will be seen that the dogis given an upward movementto catch the work, and, by the operation of the feed-lever upon the bar L', a forward motion to carry it along. As the shuttle then moves forward the depressed portion ol' the cam-face of the crossbar M2 comes under the friction-roller m', and then the spring l' draws the bar L and feeddog downward and backward.

The feed-lever I has formed in its upper face a longitudinal groove, in which fits a swiveling tulcrum-block, n, pivoted on a pin projecting downward from a longitudinal adjustable bar, N, the upper edges of which are fitted into dovetail guides formed on the bed-plate. A set-screw, N', passes down through a slot in the bed-plate, engages the rear end of the adjustable bar N, and serves to bold it at any point to which it may be adjusted. The position of the swiveling block n, of course, governs the extent ofthe movement of the forward end of the feed-lever.

From the foregoing description it will be perceived that I have produced a new four-motion feed, the various elements of which are so combined and arranged as to have a steady and certain movement easily and accurately' adjusted.

In Fig. 3, which illustrates the general structure of my improved take up, I have shown the front plate of the head C in dotted lines simply to indicate the relative positions of the parts. The letter O in this figure, and also in Figs. 1 and 4. designates the needlebar carrying the cam-grooved cross-head O', in the groove of which, indicated by dotted lines, the wrist-pm o, projecting from the face of the rotary disk D, plays to give the proper up-and-down movement to the needle-bar in a well-known manner. Just below the crosshead O' there projects from the needle-bar to the right, as viewed from the front, a lug, o', from which projects forward a pin carrying a friction -roller, o2. This friction-roller o, as the needle-bar moves up and down, plays against the irregularly-curved or cam-shaped edge oi IDO IOS

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2Min!- an arm, P,whichis held-against it-bya spring, i p, (shown'indotted lines in Fig. t3, and| in lfull `of said plate.

Q indicates adisk (having its edge-serratedfor a purpose Ahereinafter explained) arranged against theprojecting end of thestud p, and having a central hole coinciding; with the, screw-.hole of said stud.

R indicates the take-up arm having the usnalhook at its lower end, and atits upper end acentrally-bored ,circular head, R', having formed in its rear` facean annular irecess, r, in which is arranged aconvolute spring, S, the outer end of which is secured to the head of the arm B. by being passed .througha hole in the same, while its inner end is ,similarly secured to the disk Q. A `shoulder-,screw,.Q, is passed through the head R of thearm R, and its annular shoulder-q sets against the disk Q,.while its screw is driven into the central screw-hole of the stud pv. V The arm P- is thus held in proper position and the spring S secured in the-recess 1', between the. head R and 4the disk Q, the plain-shouldered portion of the screw Q forming a pivot, on which the arm R swings. A stud, t, projecting from the face of the front plate, limits the ymovement of the arm R tothe right or outward.

The parts being-in posit-ion as now described and shown, whenthe disk Q, by means of its serrations, is turned in the direction of the arrow, Figf, the inner end of the spring S will be carried with it, the outer end of said spring moving in the opposite direction andl carrying the arm Ragainst the stud t, and it is obvious that the flirtherthedisk is then turned the greater will be the tension with which the spring holds the armR outward or against the stud t, and the disk Q, -it will be seen, thus serves to regulate the tension of the spring. Now, when the needle-bar is at theL upper por- 'tion of its movement, as shown Ain Fig. 3, the

friction-roller o2 bears against the but slightly curved portion Pl ofthe edge of the arm P, and consequently the said arm is forced to the left, against the tension of its spring p, and the stud p in turning carries the disk Q with it, moving the inner endof `the spring Sain the direction opposite to that indicated by the arrow, and consequentlyd'ecreasing the tension of said spring and they force with which it presses the arm R outward. At this point of the movement of the needle-bar it will be understood that the needle-thread isfdrawn up bythe bar, and there is no slack to be taken up hence the decreased vtension of the convolute spring S permitsthe arm R to readily answer the pull of thethread and move inward to assume a positionready to move, outward andtake up the4 slack ofthe thread when the bargagain.,moves downward and brings thel roller o2 against the edge of the iextended .curve P2, at :which point the spring p is permitted to draw the arm P to the right, and turn the stud p and disk Q'to increase the tension `of-the spring S, so` that the take-up ,arm Rf. will be forced outward to take up the 'slack inthe thread. As the needle-bar now moves farther downward, the roller o? is carriedk out of4 ithe curve P2, and against the straight .edge P3, forcing. the arm P again to the left, decreasing the tension of spring S as before, so that thetake-up arm R readily gives up the slack thread, lessening, the tension on the thread isolas not to interfere with the formation of the loop. Asmthe needle-bar rises the operation of the take-up is-repeated in inverse order. I

The tension device proper of the needlethread, which is arranged upon the goose-neck between the needle-bar and the spool, consists ofa flat-spring-plate, T, curved downward at its rear end and supported by two fiat-topped l lugs, v`t and t2, from the front one, t', of which projects yupward a split stud, U, which fits loosely through a hole, t3, in the forward end of said `plate T, a thread-slot, t4, being cut through from said hole to the end of the plate. The rearend of the plate T is tapered to a point, T', which rests upon the top of the lug t2, towhich the plate is secured by means of a screw, V, which passes through it and .into a hole tapped in the lug, the shoulder c of said screw bearing upon the upper surface of the plate. On the under side of the plate T is preferably secured a thread hook or guide, t3. The thread is to be drawn from the spool under the plate T, through the guide t3, between the forward end of the plate and the top hat face of the lug-t', and then through the split stud U, through a thread-eye, u, on the head C, and thence through an eye, u', formed in the top of the needle-bar. It is led thence down in front of the front plate, C', as shown in Fig. 4, through a guide, w, through the hook ofthe take-up arm, and then through the lower guide, fw', to the needle. This tension device is in the main similar to one long in use, and my improvement consists in pointing the rear end of the plate T, so that the plate will rock on the point and permit the entire width of the front end to press upon the face of lug t when the plate is warped by variations of temperature or the varying strain put upon it. The similar tension-springs heretofore used have had extended rear bearing-edges, and, owing to the great difficulty in forming and keeping this edge of a spring-plate precisely parallel with the front bearing-face, the spring so formed is very unreliable, as is well known, for when the rear transverse edge is forced snugly against its seat one edge only of the front bearing-face is generally close upon the top face of the forward lug, so that there will not be a proper pressure upon the thread.

InV placingthe parts of the machinetogether ICO IIO

the oscillating levers F and H are inserted through the lower openingr of the goose-neck, and secured in place by the pin f, inserted from the outside. The friction-roller a is then slipped upon the shaft and secured by any suitable means. In the present instance a a shoulder is formed on the shaft to limit the rearward movement ofthe roller, and a washer, a', held by a pin, is placed in front. The shaft is then inserted through the rear screwthreaded opening of the goose-neck to the left of the lever H, through the slot F' in the upper end of lever F. and its front end projected far enough in front to permit the disk D and sleeve d to be placed thereon and secured in any suitable manner-as, for instance, a pin passing through the sleeve and shaft. The shaft is then drawn rearwardly to seat the sleeve din its bearing, this sleeve forming the (as will be remembered) front journal of the shaft. The cam D', with its sleeve d', is then slipped upon the rear end of the shaft, an opening in the front end ofthe cani titting over a projection, d, on the shaft, in order to prevent the cam from turning independently. The removable screw-threaded bearing b is then passed over the rear end of the shaft and screwed firmly into the opening in the gooseneck, passing also over the sleeve d' and forming the bearing of this sleeve, which, it will be borne in mind, forms the rearjonrnal ofthe shaft.

Theinteror parts of the machine, it will be seen, are, by their construction and arrangement, all enabled to be properly placed and secured from the outside, and thus a great convenience effected.

I do not confine myself to any particular shape ofcam at the upper end ofthe oscillating arm F, as a di'erent shaped cam might be used and the driving-shaft turned in the opposite direction 'with the same result.

Having now described my invention, what I claim is- 1. The combination, with the needle -bar of a sewing-machine, the connected drivingshaftjonrnaled in the goose -neck above the bed-plate and provided with a crank -bend, and a shuttle-lever fulcrumed below the bedplate, of an intermediately-fulcrumed motiontransmitting lever having at its upper end a curved cam-slot, substantially as described, embracing the crank-bend of said drivingshaft, and having its lower end suitably connected with the shuttle-lever, the lower arm of said motion-transmittin g lever being elastic in a direction at an angle with its movement of oscillation, but rigid in the direction of its said movement, essentially as set forth, whereby a varying movement with respect to the needle is given to the shuttle, and the lower end ofthe motion-transmittin g lever is enabled to accommodate itself to the arc of movement of the rear end of the shuttle-lever.

2. The combination, with the driving-shaft of a sewing-machine and an oscillating lever fulcrumed under the bed-plate, of an intermediate motion-transmitting lever connected to the lever below the bed-plate, and with the drivin g-shaft, the said levers beingconstructed, as specified, whereby the end of one may yield to conform to the are of movementof the connected end of the other, substantially as described.

3. The combination, with the driving-shaft of a sewing-machine, journaled in the gooseneck, and a shuttle-lever fulcrumed below the bed-plate, ofan in termediately-fulcrumed oscillating lever having its opposite ends suitably connected with the driving-shaft and shuttlelever, respectively, and its lower arm elastic in a direction at an angle with its movement, but rigid in the direction of its movement, substantially as and for the purpose set forth.

4. The combination, with the driving-shaft of a sewing-machine,journaled above the bedplate, and a lever fulcrumed below the bedplate, of the motiontransmitting oscillating lever F, having its lower arm formed of a flatspring plate, F2, provided at its lower end with suitable means forits connection to the lever, and its upper end loosely connected with thc driving-shaft, substantially as described.

5. In a sewing-machine, the combination, with the vibrating feed-lever I and the looselyconnected bar L', carrying the feed-dog L and a suitable spring for holding said bar normally in its lowermost and rearmost positions,of the rock-shaft M, provided with the arm m, bearing against the under side of said bar, the shuttle-lever and suitable intermediate devices operated thereby for rocking said rockshaft at proper intervals, substantially as and for the purpose set fort-h.

6. In a sewing-machine, the combination, with the vibratory feed-lever I and the looselyconnected bar L', carrying the feed-dog L, of the rock-shaft M, provided with the arm m, bearing against the under side of said bar, and the rear arm, M', extending under the bedplate, the shuttle-lever provided with the camfaced cross-bar m2, arranged to operate upon the free end of said arm M', and a suitable spring arranged to hold the bar L' normally in its rearmost and lowermost positions, sub stantially as described.

7. In a sewingmachine, the combination, with suitable thread-guides, the spring-actuated cnrved arm P, take-np arm R, loosely pivoted to said curved arm, and the spring S, having one end connected to said take-up arm, and the other end connected to the said curved arm, and the needle-bar provided with a suitable projection for operating against the edge of said curved arm, substantially as described.

8. The combination, with the curved arm P, having the stud p' arranged to turn in a hole in the front plate, C', of the disk Q, arranged against the t'ront end of said stud, the take-np arm It, having its head arranged against said disk, and the spring S, having one end secured to said disk and the other t0 the head of the IOO lever, and the shouldered screw Q', securing said tension-plate, substantially as and for the said disk to said stud and forming the pivot purpose set forth.

of said take-up arm, substantially as described. In testimony whereof I have hereunto set 9. The oombination,with the atfcopped supmy hand in the presence of two subscribing 5 porting-lugs t' t2, the former or front one of Witnesses.

which is provided with an upWard-projectin g split stud, U, of the flat elastic tension-plate LEVIS H' DAVIS' T, having at its forward end a hole tting Witnesses:

loosely around the stud U, and an open slot J AMES L. NORRIS,

Io leading from said hole through the end of the ALBERT H. NORRIS.

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