US389788A - bolton - Google Patents

Description

- 2 Sheets-Sheet l.'

(No Model.)

' J. BOLTON.

TAKE-UP POR SEWING MACHINES.

Patented Sept. 18, 1888.

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N. PETERS. Pmlwgrlpher. Washington. DA C.

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J. BOLTON.

TAKE-UP' POR SEWING MACHINES.

' No.1s899788.. .Patented sept. 18, 1888.

NA PETERS. Pnulbumugnpber, wumivgmn. D. C,

UNITED vSTATES vPATENT Ormes.

JAMES BOLTON, OF NEW YORK, N. Y.

TAKE-UPFOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 389,788, dated September 18, 1888.

Application filed December 8. 1887. Serial No. 257,322. (No model.)

To all whom it may concern:

Be it known that l, JAMES BOLTON, a citizen of the United States, residing atNew York, in the county of New York and State of New York, have invented certain new and useful Improvements in Take-Ups for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

The object of my invention is to provide a positive and silently-operating take-up mechanism for sewing-machines, and one which is more particularly adapted for that class of sewing-machines having rotary shuttles. Machines of this class require a large amount of slack needle-thread to make loops of sufficient size for the shuttles to pass through, and as it is necessary in the successful operation of such machines to take up these large loops and tighten the stitches during the time occupied by the shuttlein making about a quarter-revolution, or between the time when a loop of needle-thread will havebeen carried more than half-way round the shuttle and the time when the eye of the needle will have entered the work for the formation of the next stitch, it has been a. somewhat difficult problem to provide a take-up mechanism to meet this require- Y ment, and, which will still have a' smooth,

steady, silent, and positive action. My improved take-up. mechanism, however, meets this desideratuni, and although specially designed for the rotating-shuttle machines it may also be advantageously-employed in revolvinghook machines, as also in vibrating or oscillating shuttle machines.

In carrying my invention into effect I provide the needle-bar-operating crank with an extension forming a second crank, the crankpin of which is about ninety degrees of a circle trom or behind the needle-bar-operating crank-pin. The take-up arm, which extends outside or in front of the face-plate of the machine, is carried by a small rock-shaft pivoted to one side of the head7 at the 'forward-end of the bracket-arm, and preferably having its center in the horizontal plane of the center of the driving-shaft. The said rock-shaft has a slotted operating-arm extending within the head, andV within the slot of the said arm, to

, operate the same, wor-ks the pin of the second crank, above referred to. Thus the needlebar and take-up are operated by what may be termed a double crank, and as the take-up rock-shaft isat one side of the head the takeup crank-pin will be close to the center of motion of the take-up arm at the time when a stitch is to be tightened, so that only a comparatively'short distance need be traversed by the said crank-pin to give a sufcient throw to the take-,up arm to draw up the loop. Thus the first part of the take-up movement will be very rapid; but as the operation ot tightening the stitch is approaching completion the takeup crank-pin will be receding from the takeup rock-shaft in the slotted operating arm of the latter, and as the leverage of the said pin on the said arm will therefore gradually increase tlic movement of the takeup arm will correspondingly decrease as the stitch is being tightened, the take-up arm coming to a full stop before beginning its return movement, just asthe stitch is fully drawn up into the work.. There will therefore bc no sudden jerk on the thread when the strai u comes, and there will consequently be little danger of breaking the thread in the rapid operation of the takeview of a sewing-machine embodying my invention. Figs. 2, 3, and et are front views of the head of the machine, showing the parts in4 different positions, these views also showing the' positions of the needle and shuttle corresponding to the different positions of the takeup. Fig. 5 is a detail perspective view of the double crank for operating the needlebar and take-up.

A denotes the work-plate of the machine, and B the bracket-arm thereof, the latter being provided at its forward en d with the usual depending head, C,` in whichI the needle-bar l) and presser-bar E navet-heir bearings. Fis the driving-shaft,having the crank f, connected by the pitmau-lever G with the rotatingshaft H, beneath the work-plate, the said shaft H carrying at its for ward end the rotating shuttle I. rlhe said shuttle is carried by clamping-arms forming no part of the present invention, but fully shown and described in my application No. 243,061, tiled July 1, 1887.

The driving-shaft is provided at its forward In the drawings, Figure l is a sectional side' IOO end with a double crank consisting of the arm f, having the pin or studfi, provided with an extension, f3, having a pin or roller-stnd,f",

the pinf2 being surrounded by the upper end 5 of the pitman d,conneeted to the needle-barD by the collared stud d. The armf is rigid with the said driving-shaft, and the arm or extensionf3 is rigid with the said armf.

The take-up arm J is carried by a sleeve or Io tubular rock-shaft, L, supported bya stud or pin, M, screwed into one side of the head C, said take-up arm extending outside or in front of the faceplate c. rIhe sleeve or rock-shaft L is provided with an operati rig-arm, N,having a slightly-curved slot in which works the pin or roller-studj" of the double crank, and the said rock-shaft is preferably so located that its center is in the same horizontal plane as the center of the driving-shaft F.

To Secure a proper timing of the parts, the studs or crank-pins f2 and f* are arranged about ninety degrees in the arc of a circle from each other, the latter following the former; but the exact arrangement of these pins is not essential, as the correct timing can be effooted by making the slot of the operating-arm N more or less curved or irregular. By making the slot of the arm N somewhat curved,

as shown in the drawings7 a better timing of 3o the parts is secured. The crank-pinsf" and f4 are in different radiiof the circle or circles in which they rotate, and are preferably at aboutninety degrees from each other,as shown in the drawings.

In the operation of my machine the ncedle descends and the loop thrown out therefrom is caught by the shuttle when the parts are in the position shown by Fig. 2, and as the shuttle moves forward to the position 4o shown by Fig. 3 the take-np arm descends,

giving up or yielding the thread to permit the loop to he properly expanded around the shuttle, and when the body of the latter is about half through the loop the take-up begins its upward movement, quickly drawing up the loop out of the way of the advancing point of the shuttle, the take-up operation being completed and the stitch tightened when the parts arrive at the position shown in Fig. 5o -1 when the needle is inst beginning its descent for the next stitch. rIhus the whole take-up operation is effected during the time required for about a quarter-revolution of the driving-shaft, the larger part of the movement of the take-up being effected rapidly,

owing to the close proximity of the crankpin f to the center of movement of the takeup arm; but when the operation of tightening the stitches is approaching completion 6o the said crank-pin has reeeded considerably from the take-up rock-shaft, traveling in the slot of the operating-arm, and the leverage of the said pin on said arm is therefore correlextending in front of the face plate and servspondingly increased, and the movement of the take-up arm is correspondingly lessened, so that by the time the last pull of the takeup on the thread in tightening the stitch occurs the take-up has nearly come to a stop, and there is therefore no sudden jerk on the thread when the greatest strain comes, and the danger of breaking the thread by the takeup is therefore reduced to a minimum, as above stated.

I claim- 1. In a sewing-machine, the combination, with the needle operating shaft provided with a double crank having two crank pinsor studs which are in different radii of the circle or circles in which they rotate, of a needle-bar operatively connected with one of the said crank-pins, and a take up rock-shaft having rear and front arms, the said rear arm being operatively connected with the other of the said crank-pins, and the said front arm ing as the take-up proper.

2. In a sewing-machine, the combination, with a bracket-arm and its head, of a needleoperating shaft jonrnaled in said arm and provided at its forward end with a double crank having two crank-pins which are in different radii ofthe circle or circles in which they rotate, a needle-bar operatively connected with one of the said crank-pins and having vertical bearings in the said head, and a take-up rock-shaft journaled to one side of the said head and provided with a take-np arm extending in front of the face-plate of the said head, and with a slotted operating-arm extending within ihe head and being engaged by the other of the said crank-pins.

3. In a sewing-machine, the combination, with a bracket-arm and its head, of a needleoperating shaft jonrnaled in said arm and provided at its forward end with a double crank having two crank-pins which are in different radii of the circle or circles in which they r0- tate, a needle-bar operatively connected with one of the said crank-pins and having vertical bearings in the said head, and a take-up rock-shaft journaled to one side of the said head, and provided with a take-up arm extending in front of the face-plate of said head, and with a slotted operating-arm extending within the head and being engaged by the other of the said crank-pins, the center ofthe said rock-shaft being in the same horizontal plane as the center of the said needle-bar-operating shaft.

In testimony whereof I affix mysignatnre in presence of two witnesses.

JAMES BOLTON.

Vitnesses:

HENRY CALvnn, EWELL A. DICK.

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