US1385048A - Thread-controlling device for sewing-machines - Google Patents

Description

P. A. HERB. THREAD CONTROLLING DEVICE FOR SEWING.MACHINES.

APPLICATION FILED JULY 27 I9I8.

Patented July 19, 1921.

I I I II IIIII I M I INVENTOR WITNESSES a w-W- I B P. A. HERR.

THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATION FILED JULY 27,1918- 48. I Patented July 19,1921.

4 SHEETS-SHEET 2.

Z 1 L 2/ "M INVENTOR N I N mum-Mm W ATTORNEY P. A. HERR- THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATION FILED JULY 27, 1918.

Patented July 19, 1921.

4 SHEElS-SHEET a.

m ssw mw T0 TAKEUP N ml====7 m WITNESSES ATTORNEY P. A. HERR.

THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATION FILED IULY 27.1918.- 1,385,048, Patented July 19, 1921.

4 SHEETS-SHEET 4.

S E S E N W W.

PARK A. HERB, OF HILLSIDE, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFAC- TURING COIHPILN'Y, A CGRPORATION OF NEW JERSEY.

THREAD-GONTROLLIN DEVICE FOR SEWINGJJIACHINES.

Application filed July 27,

T0 aZZ whom it may concern.-

Be it known that I, PARK A. HERB, a citizen of the United States, residing at Hillside, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in ThreadControlling Devices for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates'to thread-controlling devices for sewing machines 01" that type in which the needle is vibrated laterally to produce zigzag stitches. In machines of this type heretofore constructed and particularly those in which the vibratory movements of the needle produced a seam of extreme width, difficulty was experienced in controlling the under thread so asto properly position it for the take-up action and secure its concatenation with the needle-threadin the proper position within the material.

The invention has for its object the construction of a thread-controlling device whereby that portion of the under thread to be drawn into the work will always be positioned in substantial a-linement with the prospective needle-puncture regardless of the relation to the previous stitch of the tl1readcase supplying such lower thread, so that the upperthread loop shall be subjected below the work in the stitch setting action to a direct pull without appreciable deflection from alinenient with the needlepuncture. V

The device herein shown applied to the machine forming the subject oi my prior Patent No. 1,329,763, issued February 3,1920, and constitutes an improvement upon the under thread pull-off and positioning device disclosed in my said patent.

It comprises a thread-positioning element sustained for movement upon the under side of the throat-plate and actuated by a connection with a crank-arm secured to the lower end of a vertically disposed rock-shaft suitably journaled uponthe upright portion of the sewing machine bracket--arm. Near the upper end of the-rock-shaft is secured a second crank-arm to which'is pivotally attached one end of a link whose other end is adjustably secured to a segment-arm of a rocking member journaled upon the sewing machine bracket-arm. The rocking member is provided with a second arm operatively Specification of Letters Patent. 7

Patented July 19, 1921. 1913'. Serial No. 246,984.

connected with a cam-disk suitably journaled upon the sewing machine bracket-arm and driven from the main-shaft of the ma chine, whereby operative movements are im parted to the thread-positioning element. This cam-disk is also utilized for imparting vibratory movements to the needle-bar sup porting frame as well as bodily movements to the loop-taker to permit the one to cooperate with the other in making a widethrow zigzag seam. The adjustable connection between the link and the segment-arm permit variation in the throw of the thread positioning element to correspond with the variations in the vibrations or throw of the needle.

.The preferred form of the invention is shown in the accompanying drawings in which Figure l'is a rear side elevation of a machine embodying the present improve ment; Fig.2 a top plan and Fig. 3 a bottom plan view of the machine showing the mech anism for actuating the thread positioning element; Fig. l is a side elevation, partly in section, showing the upper and under threads concatenated at the extreme right hand line of needle-punctures (Z, the needle having risen to its highest position and moved to the left in line with the needlepuncture c. Fig. 5 is a similar side elevation showing the needle descending in line with the needle-puncture c with the under thread deflected in the same direction. Fig. 5 is a detail sectional elevation showing the position of the upper and under thread loops during the final portion of the take-up action. Fig. 6 is a bottom plan view of the throat-plate, feed-dog and threadengaging element, Fig. 7 is a sectional elevation of the same parts taken through the line 02-50, Fig. 6' and Fig. 8 illustrates a portion of a seam made by the machine of the present improvement.

' The sewing machine embodying the present improvement comprises the work-supporting bed 1 from which rises the hollow standard 2 with the tubular overhanging arm 3 provided with head 4. The mainshaft 5 extends lengthwise within the overhanging arm and is provided at one end with the balance-wheel 6 provided with grooved belt-wheel 7 while the other end of the shaft has fixed thereon the cam-disk 8 for imparting operative movements to the needle-bar 9 carrying the needle 10 and also for actuating the stitch-setting means or take-up 11 in a well-known manner. Journaled in the head a is the usual springpressed presser -bar 12 provided with the presser-foot 13.

Opposed to the presser-foot is the feeddog 14L supported by the feeding frame 15 which receives reciprocatory feeding movements from the feed rock-shaft 16 actuated from the main-shaft 5 by means including a pitman 17 pivotally connected to a crankarm 18 of the feed-rock-shaft 16. Rising and falling movements are imparted to the feed-dog by means of the feed-lift rockshaft 19 having at one end an arm 20 operatively connected with the feed-bar frame 15 while near its other end the rock-shaft is provided with a yoke 21 embracing and re ceiving motion from the eccentric 22 carried bythe rock-shaft 23 journaled in bearing bosses depending from the work-supporting bed 1. The rock-shaft 23 is actuated from the main-shaft 5 by means including the pitman 21, a rocker 25, link 26 and crank-arm 27 in the well known nianner.

The needle-bar 9 is fitted to reciprocate within a pair of vertical sleeves 28, one of which is shown in Fig. 4, each sleeve being carried at the end of a rod 29 adapted to slide within suitable apertures formed in the head 1. Vibratory movements are imparted to the needle-bar from the cam-disk 29, secured upon a cross-shaft 30 suitably journaled upon the bracketarm and driven by gearing from the main-shaft 5'. The disk 29 is provided with a cam-groove 31 entered by a roller-stud 32 carried by the swinging segment-lever 33 'which lever is embraced by the clamp-block 3 1 adjustably secured thereon by the screw-stud 35. The clamp-block has pivotally secured thereon one end of a link 36 whose other end is operatively connected with the rocker 37 j ournaled upon the cross-shaft 38 carried by the standard 2. The upper end of the rocker 37 has a link connection 39 with a crankarm to of a vertically disposed rock-shaft 11 provided with a second crank-arm 12 having a link connection 13 with the needlebar sleeve 28. a

Opposed to the needle and adapted to cooperate with it inthe formation of stitches is the lower thread mechanism. It coinprises the loop-taker, shown in the form of a shuttle let, whose field of action is crosswise of the line of seam, containing the thread-case 45 and actuated by the driver 46 carried by the-cross-shaft 47 and suitably driven by bevel gears 4.7, shaft 18 and gears 419 and 50, the latter of which is secured to the oscillating rock-shaft 23. The loop taker is suitably journaled for oscillatory movement in a raceway formed in the carrying frame 51 mounted to slide upon abar 52 suitably supported upon the under side of the work-supporting bed 1. The looptaker 44 with its supporting frame 51 receives bodily movementsby means of a link 53 one end of which is pivotally connected with the frame 51 by the screw-stud 54: while its other end is operatively connected tothe lower end of rocker 37 by the screw-stud 55. Recessed in the work-supporting bed 1 is the usual throat-plate '56 secured to the bed by the screws 57, the throat-plate being provided with suitable apertures 58 through which project the toothed work-engaging portions of the feed-dog 14;. The throatplate is also provided with the elongated needle-aperture 59 to receive the vibratory needle 10. A supplementary throat-plate 60 is provided to close the opening in the worksupporting bed 1 so as to make it flush with the. main throat-plate 56.

From the foregoing it will be readily understood that vibratory movements are imparted by the cam disk 29 to both the needle 10 and the loop-taker or shuttle 4: 1, the two performing lateral movements in unison in the production of a zigzag seam, the amplitude of lateral throw of the needle and the loop-taker being determined by suitable adjustment of the position of the clamp-block 34 upon the segment-lever 33. The mechanism for actuating the needle and loop-taker t just described is all substantially like that Vshrown in my patent above referred to.

In the operation of the machine which, in the present instance, produces a fourstitch zigzag seam, the needle 10 makes four descents through therinaterial m before reversal of its direction of vibration, as clearly shown in Figs. 1 and 5. In order to make a zigzag seam of the extreme width of two and one-half inchesor more for which the machine of the present improvement has been especially constructed it is important that special means be devised to draw ofif and 7 control the under thread so that when the take-up 11 acts to set the stitch the portion of the under thread to be concatenated with the upper-thread loop will be disposed in substantial alinenient with the needle-puncture just made regardless of the lateral position of the needle. 1

To this end, the under side of the throatplate 56 is formed with a channel 61 adapted to receive and guide the thread-positioning element 62 in the shape of a flat bar.

provided with a thread aperture 63 near one end. The thread-positioning element is retained in its channel by means of a cap-plate 6 1 secured in position by the screws 65. To impart the desired operative movements to the thread-positioning element 62, its thickened end 66 is rigidly secured to a sliderod 67 by a screw-stud 68 the other end of the slide-rod having pivotally attached thereto by the screw-stud 69 one end of a link 7 0 whose other end is connected by the pivot screw 71 with, the cranlearm 72 secured to the lower end of the vertically disposed rock-shaft 73 suitably journaled in bearing bosses 741 at the side of the standard 2. The upper end of the rock-shaft 73 has rigidly secured thereto a crank-arm 'Z' 5 connected by a screw-stud 76 with one end of a linlr77 whose other end is provided with a screw-bolt 78 whose head enters the guideway T9 formed in the segment-arm 80 of the rocker 81. The rocker is secured upon a bearing stud 82 journaled in the boss 83 upon the bracket-arm 3. The rocker is also provided with a second arm 8-1 having a roller-stud S5 entering a cam-gro0ve 86 formed upon the cam-disk 29. It will be understood that through the connections just described the movements of the thread-engaging element 62 are maintained in timed relation with the lateral jogging movements of the needle 10 and the loop-taker 44, all of these parts deriving operative movements from the cam-disk 29. It will be observed that the thread positioning element 62 is actuated entirely independently of the lower thread handling mechanism.

As represented in Figs. at and 5 the fourstitch zigzag seam, comprising stitches at the punctures a, b, c and (Z, has been completed and the needle 10 has moved suliiciently to the left to again enter the material m in line with the puncture 0 the material having in the meantime been advanced by the feeding mechanism. In this position of the parts, the under thread extends in a substantially straight line from its source of supply in the loop-taker to the position where it is last locked with the needle-thread within the material at the previously formed stitch in the puncture (Z. As the needle performs its lateral movement preparatory to its next. descent the thread positioning ele ment 62 has drawn off and moved the under thread to the left, as clearly shown in Fig. 5, or in a direction toward the needle-puncture about to be formed at a, so that when the loop-taker has passed through the loop of needle-thread, the under thread will occupy a position favorable for the take-up action. As the take-up begins to draw up the slack needle-thread it will readily slide along the lower thread until both upper and lower threads are securely locked in the material at the puncture 0.

After the setting of the stitch at c the needle 10 and loop-taker 41-4: continue their movement to the left to form successive stitches in line with the punctures at 7) and a, the thread positioning element 62 moving correspondingly to draw oil and deflect the lower thread to a position favo able for the take-up action.

When the stitch has been set in line with the puncture a, the needle and loop-taker begin to retrace their movements to the right thread to the to form successive stitches in line with punctures Z), c and (Z, the thread-positioning clement following such lateral movements so as to draw off and position the lower right and favorably to the take-up action, as in the formationof the previous stitches of the zigzag seam.

Having thus set forth the nature of the invention, what I claim herein is- 1. In alock stitch sewing machine, in combination, upper thread mechanism including a reciprocating needle, cooperating lower-thread mechanism including a looptaker, means for producing relative jogging movements between both needle and looptaker and the work, means engaging the lower thread leading from the last stitch to position the same in substantial alinement with the location of the succeeding stitch in either direction, and means acting upon the upper thread for setting the stitch.

2. In a lock stitch sewing machine, in combination, upper thread mechanism including a reciprocating needle, cooperating lower thread mechanism including a looptaker whose field of action is crosswise of the line of seam, means for producing relative jogging movements between both needle and loop-taker and the work, means engaging the lower thread leading from the last stitch to position the same in substantial alinement with the location of the succeed ing stitch in either direction, and means acting upon the upper thread for setting the stitch.

3. In a sewing machine, in combination, upper thread mechanism including a reciprocating needle, cooperating lower thread mechanism including a loop-taker, a mainshaft, an actuating element thereon, connec tions with said actuating element for imparting lateral movements to the needle and loop-taker, a thread positioning element for drawing oti" lower thread, and connections with said shaft, independent of the firstnamed connections, for imparting to the threadpositioning element movements similar to and in timed relation with those of the needle and loop-taker.

a. In a sewing machine, in combination, upper thread mechanism including a reciprocating needle, cooperating lower thread mechanism including a loop-taker, a mainshaft, an actuating element thereon, connections with said actuating element for imparting lateral movements to the needle and loop-taker, a thread positioning element for drawing oft lower thread, a connection with said shaft, independent of the first-named connections, for imparting to the thread positioning elements movements similar to and in timed relation. with those of the needle and loop-taker, and means for adjusting the amplitude of movement of said thread drawing element.

"mechanism including a '5. In a sewing machine, in combination, upper threadrmechanism including a reciprocating needle, cooperating lower thread loop-taker, a mainshaft, means actuated by said main-shaft for imparting to said needle and loop-taker lateral movements, a rock-shaft operatively connected with the main-shaft, a thread p0- sitioning element adapted lateral movements of the needle and looptaker, and a connection between said rockshaft and thread positioning element for imparting operative movements to thelatter. Intestimony whereof, I have signed my name to this specification. V V

PARK A, HERE.

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