US2254794A

US2254794A - Feeding mechanism for sewing machines

Info

Publication number: US2254794A
Application number: US304285A
Authority: US
Inventors: Frederic M Card
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1939-04-01
Filing date: 1939-11-14
Publication date: 1941-09-02
Anticipated expiration: 1958-09-02
Also published as: CH218347A; DE868098C; CH217202A; GB534346A; GB534345A; DE750200C; FR863965A; US2216096A

Description

Sept. 2, 1941. v F. M. CARD 2,254,794

FEEDING MECHANISM FOR SEWING MACHINES Original Filed April 1, 1939 5 Sheets-Sheet 1 Freda/i0 all Car-(1x W LtneM: Z: 4

F. M. CARD Sept. 2, 1941.

, 1939 5 Sheets-Sheet 2 Original Filed April 1 3 1 vv 2444 we ederi0 JZ ain arty/rm;

Sept. 2, 1941. F. M. CARD FEEDING MECHANISM FOR SEWING MACHINES Original Filed April 1 5 Sheets-Sheet 5 31 won fox w w Z L I 4 6 2 I 7 6 96 4 n 3. w w E m w 7 Sept; 2, 1941. F. M. CARD 2,254,794

FEEDING MECHANISM FOR SEWING MACHINES Original Filed April 1, 1939 5 Sheets-Sheet 4 31 vuc/nf/o v .E-ederie I ard Sept. 2, 1941. CARD 2,254,794

FEEDING MECHANISM FOR SEWING MACHINES 4 Original Filed April 1, 1939 5 Sheets-Sheet 5 Patented Sept. 2, 1941 T OFFICE 2,254,794 FEEDING MECHANISM FOR. SEWING MACHINES Frederic M.- Card, Bridgeport, Conn., assignor to The Singer beth, N. J

Original application A 265,397. Divided and ber 14, 1939, Serial No.

16 Claims.

This is a division of my prior patent application Serial No. 265,397, filed Apr. 1, 1939, the pres- Manufacturlng Company, Elizaa corporation of New Jersey pm 1, 1939, Serial No. this application Novem- 304,285.

ent invention relating to feeding mechanisms for sewing machines and having for its primary ob ject to provide comparatively quiet running and durable means for automatically controlling. the work-advancing movements of the feeding mechanism of a sewing machine, at high speeds of operation of the machine.

More specifically, the present invention aims to provide means operable at comparatively high speeds for automatically controlling forward and reverse work-advancing movements of a sewing machine feed-dog.

A further object of the invention is to provide convenient means for changing the effective work-feeding movements of a sewing machine feed-dog performed in a complete cycle of operation of automatic controlling means for the feeddog actuating mechanism.

Other and more specific objects of the invention will be apparent from the following description and claims.

The invention consists in, the feed-actuation controlling mechanism as hereinafter described in connection with the accompanying drawings which illustrate a preferred embodiment of. the invention and in which:

Fig. 1 represents a vertical longitudinal section, partly in front elevation, of an ornamental-stitch sewing machine containing the improved feeding mechanism. Fig. 2 represents a bottom plan view of the machine. Fig. 3 represents a vertical section through the bracket-arm standard of the machine on substantially the line 33 of Fig. 1. Fig. 4 represents a cross-section of the bracketarm to include both of the cross-shafts which carry the needle-vibration and feed-controlling eccentrics. Fig. 5 is a detail view in front elevation of the feed-indicator disks. Fig. 6 is a diagrammatic representation of the feed-controlling connections.

The sewing machine illustrated in the drawings has the usual work-supporting bed-plate I. from one end of which rises the tubular standard 2 of a bracket-arm 3 which overhangs the bedplate I and terminates at its free end in a head 4.

Rotat'ably journaled in the bracket-arm 3, to extend horizontally lengthwise thereof, is a main actuating or needle-reciprocating shaft 5 carrying at oneend a belt-pulley 6. At its opposite end, the shaft 5 carries a counterbalanced crankdisk I connected by the usual link 8 with a vertically disposed needle-bar .9 carrying at its lower end a needle I0.

The needle-bar 9 is journaled for endwise reciprocation in a laterally swinging frame ll pivotally hung at its upper end upon a fulcrum-pin l2 within the bracket-arm head 4. The frame I I is, as usual, provided adjacent its lower end with an arcuate slot I3 to receive a guide-stud l4, and is also pivotally connected by a screw l5 to one end of a needle-bar vibrating pitman I 6. At its opposite end, the pitman l6 has a split strap l'l embracing a rotary needle-vibrating eccentric l8 constructed substantially as more fully disclosed in the U. S. patent to C. F. Gray, No. 1,020,089, Mar. 12, 1912. In general, the eccentric l8 has an enlarged shaft-aperture l9 and extends laterally from a frame 20 adjustably carried by a disk 2| secured by a screw 22 upon a cross-shaft 23. The cross-shaft 23 is disposed below and substantially normal to the needle-reciprocating shaft 5, being journaled at the front of the brack= et-arm 3 in a bearing provided by a detachable cap-plate 24. and at its rearward end in a frameboss 25. Adjacent the eccentric l8, there is secured to the cross-shaft 23 a gear-wheel 26 driven by a spiral-gear 21 carried by the needle-reciprocating shaft 5.

The spiral-gear 21 is the shaft 5 to provide said gear 21, thereby to change eccentric l8. To this end, the a hub 28 extending into an annularly recessed collar 29 secured by screws 30 upon the shaft 5, said collar 29 being secured to the gear-hub 28 by set-screws 3|. By freeing the set-screws 3|, the shaft 5 and spiral-gear 21 may be relatively rotated to change the timing of the eccentric I8, the gear-hub 28 being preferabl provided with spanner-apertures 32 to receive a suitable tool for effecting adjustment of the spiral-gear 21.

In the present case, the ratio of the

gears

26 and 21 is such that the cross-shaft 23 rotates once for six rotations of the needle-reciprocating shaft 5. Consequently, the needle I0 reciprocates six times in each complete'rotation of the eccentric l8, i. e., the needle reciprocates three times while moving laterally in one direction and three times in its return lateral movement to complete a sixstitch cycle. The amplitude of the complete lateral vibration of the needle, or, in other words, the width'of the ornamental seam is determined by adjustment of the eccentricity of the eccentric it, which may be eifected by means of the usual regulating spindle 33, as disclosed in said prior Patent No. 1,020,089.

Cooperating with the needle I0, .in the formation of lock-stitches, is a loop-taker in the form preferably secured upon for angularly adjusting the timing of the spiral-gear 21 has of the usual rotary hook 84 having its axis of rotation substantially parallel to the cross-shaft 23, whereby the rotary hook beak rotates in a plane parallel to the lane of lateral vibration of the needle. The rotary book 84 is carried by a shaft 85 rotatably journaled in a bushing 88 secured in a lug 31 at the under side of the bedplate I. Suitably secured to the hook-shaft 88 is a bevel-gear 38 in mesh with a similar gear 88 carried by one end or a rotary hook actuating shaft 48. The shaft 48 extends horizontally lengthwise of the bed-plate I and is journaled for rotation in a tubular feed-lift rock-shaft 4| which, in turn, is journaled to rock in spaced bearing-

lugs

42 and 43 depending from the bedplate I. At its end opposite to the bevel-gear 88, the hook-actuating shaft 48 carries a pulley 44 connected by a clip-belt 45 to a pulley 48 carried by the needle-reciprocating shaft 5, the

pulleys

44 and 46 being proportioned so that the hookactuating shaft 48 rotates twice for each rotation of its driving shaft 5.

The work is advanced by a feed-dog 41 of the drop-feed type, said feed-dog being opposed by a suitable presser-foot and operating through slots provided in a throat-plate 48, secured upon the bed-plate I and having the usual needle-slot 48. The feed-dog 41 is carried by a feed-bar 58 having a slot BI receiving a slide-block 52 connected by a pivot-bolt 53 to a crank-arm 54 clamped upon one end of the feed-lift rock-shaft 4|. Secured upon said feed-lift rock-shaft 4|, at the opposite end thereof, is a crank-arm 85 connected by a pivot-bolt 56 to the lower end of a pitman 81. The pitman 51 extends upwardly within the armstandard 2 and has, at its upper end, a strap embracing a feed-lift eccentric 58 carried by the actuating shaft 5. It will therefore be understood that the feed-dog 41 is raised and lowered once for each reciprocation of the needle.

The rearward end of the feed-bar 58 is pivotally supported by and between the upstanding arms 58 at one end of a feed-advance rock-shaft 88, disposed in substantial parallelism wth the feedlift rock-shaft 4| and journaled in bearing-lugs 6| and 82 depending from the bed-plate I. Clamped upon the opposite end of the feed-advance rock-shaft 88 is a depending crank-arm 88 connected by a pivot-bolt 84 to one end of a link 85, of which the opposite end is connected by a pivot-bolt 86 to a slide-block 81. The slide-block 81 is shiftably disposed in a segmental guideway 88 provided in a rocking-member 68 having a fulcrum-pin 18 extending laterally from said member substantially medianly between the ends thereof. The fulcrum-pin 18 is journaled for rocking movements in an apertured boss 1| at the lower end of a bracket 12 secured by screws 18 to the under side of the bed-plate I.

The rocking-member 88 has an ear 14 to which is pivotally secured, by a screw 15, the lower end of a pitman 18. At its upper end, the pitman feed-dog 41 is raised by the feed-lift mechanism actuated by the feed-lift eccentric 88.

In order to control the effective action of the feed-dog 41 automatically, the slide-block carrying link 88 is connected by a ball-joint 18 to the lower end of a link 18 reciprocating endwise within the arm-standard 2. At its upper end, the link 18 is connected by a ball-joint 88 to an arm 8| of a two-armed lever 8I, 82 fulcrumed upon a pivot-screw 88 threaded into the inner wall of the bracket-arm 8, the fulcrum-axis of the lever 8I, 82 being substantially parallel to the cross-shaft 28. The arm 82 of the lever II, 82 is pivotally connected to the lower end of a pitman 84 having a strap 88 embracing a feedcontrolling eccentric 88. As illustrated more particularly in Fig. 4 of the drawings, the eccentric 88 is secured by a set-screw 81 upon a shoulder cross-shaft 88 journaled at its rearward end in a bushing 88 suitably fixed in an aperture in the rear wall of the bracket-arm 8, the crossshaft 88 being disposed above the needle-reciproeating shaft 5 and in substantial parallelism with the cross-shaft 28. The forward reduced portion of the cross-shaft 88 is journaled in a shaft-sleeve 88 which is itself journaled for rotation in a bearing-bushing 8I suitably fixed in the front wall of the bracket-arm 8.

Secured upon the sleeve 88, by a set-screw 82, is the hub 88 of a spiral gear 84 in mesh with a spiral pinion 88 suitably secured upon the needle-reciprocating shaft 8, the ratio of the

gears

84 and 85 being such that the cross-shaft 88 rotates once for three rotations of the needle-reciprocating shaft 8. The spiral gear 84 preferably has its side face annularly recessed adjacent the feed-controlling eccentric 88 to receive a disk-flange 88 of said eccentric.

At the front side of the bracket-arm 8, the shaft-sleeve 88 has a disk-flange 81 preferably having a beveled indexed periphery and provided with a series of apertures 88. Adapted to releasably enter any one of said apertures 88 is a coupling-pin 88 extending from a side face of a coupling-disk I88 secured by a key I8I upon the shaft 88 for rotation therewith, but permitting limited movement of the coupling-disk I88 endwise of said shaft. The coupling-disk I88 has a knurled head I82 centrally apertured to receive the head I88 of a screw threaded into the forward end of the cross-shaft 88, the screw-head I88 serving as an abutment for a spring I84 which functions to hold the coupling-disk I88 yieldingly in contact with the disk-flange 81, with the coupling-pin 88 disposed in one of the disk-flange apertures 88. By uncoupling the disk-flange 81 and coupling-disk I88. the crossshaft 88 may be turned to change the timing of 'the eccentric 86, as will be self-evident. An

16 has a strap embracing an adjustable feedadvance eccentric 11 carried by the needle-reciprocating shaft 5. The adjustable eccentric 11 is constructed, in the present case, substantially in accordance with the disclosure in the U. S. patent to J. H. Stearns, No. 2,029,218, Jan. 28, 1936, although any other suitable or desired form of adjustable eccentric may be employed. From the foregoing description, it will be understood that the feed-dog 41 derives work-advancing and return movements of variable amplitude from the eccentric 11 and that said work-advancing movements are timed to occur when the angular cover-plate I85 is detachably secured upon the bracket-arm 8 and provides for access to the mechanism within the bracket-arm.

The described feeding mechanism is so designed that in one complete rotation of the feedcontrolling eccentric the work is fed twice forwardly and once backwardly. By employing an eccentric for the purpose described, instead of a pattern-cam, the speed of operation of the machine may be substantially increased beyond the maximum speed capacity of prior machines while, at the same time, reducing objectionable noise and wear. Furthermore, by the provision for convenient adjustments of the relative timingof themeedle-vibrating and feed-controlling eccentrics, a large variety of ornamental seams may be readily produced.

The length of the stitches is not only dependent upon the amplitude of lateral vibration of the needle I8 between successive work-penetrations thereof, but also upon the feeding mechanism, which is illustrated diagrammatically in Fig. 6 of the drawings. The feed-dog the feed-bar 58 is, as usual, raised and lowered by the feed-lift eccentric 58 having the described connections with the slide-block 52, and forward and backward movements are imparted to said feed-dog 41 by the feed-advance eccentric 11 which functions to rock the segmental guideway 68 about its fulcrum-axis 18. In any ofi-center position of the slide-block 61 in its guideway 68, the rocking movements of said guideway are transmitted by the link 65 to the feed-

rocker

59, 68, 63, as will be readily understood.

The shifting movements of the slide-block 61 in the guideway 68 are controlled by the feedcontrolling eccentric 86 through the described connections with said slide-block 61, the throw of the eccentric 86 being such that the slideblock 61 travels from one side to the other of the fulcrum-axis 18 of the guideway 68. In the position 1:, Fig. 6, of the point of maximum eccentricity of the eccentric 86, the slide-block 61 is substantially at x in the portion of the guideway 68 above the fulcrum-axis thereof and the feed-dog 41 is in a median position of its forward Work-advancing movement. In a onethird revolution of the eccentric 86, from the position a: to position 1 of its point of maximum eccentricity, the slide-block 61 travels downwardly across the fulcrum-axis in the guideway 68, during the return movement of the feeddog 41, to bring said slide-block to the point in the succeeding median position of the feeddog 41 in which the work is fed backwardly.

In the next one-third revolution of the eccentric 86, from y to z, the slide-block travels upwardly across the fulcrum-axis 10 of the guideway 68 to substantially the point 2', during the time that the feed-dog 41 has its return idle movement to a median position of forward feeding movement. In the final one-third revolution of the eccentric 86, from a to the starting point :0, the slide-block 61 travels slightly upwardly and then downwardly to the position x thereof wherein the feed-dog 41 is again advancing the work forwardly.

From the foregoing description, it will be understood that different varieties of seams may be produced by merely adjusting the timing of the feed-controlling eccentric 86, which may be conveniently effected by pulling forwardly upon the coupling-disk head I82, partly turning the feedcontrolling cross-shaft 88 and recoupling the disks 91, H10, in a newly selected relative position thereof. By means of any suitable indi-' cator-expedient, the desired relative position of the disks 91, I88, may be obtained with precision.

Still further varieties of ornamental seams may be produced by adjusting the timing of both the needle-vibrating eccentric l8 and the feedcontrolling eccentric 86, as will be apparent. In connection with the timing adjustments described, it is to, be understood that said adjustments do not'interfere with the complemental action of the reciprocating needle l8 and rotating loop-taker 34 to form stitches. The looptaker 34 accommodates the maximum lateral throw of the needle l8 eifected by the needlevibrating eccentric I8 of the machine. For still 41, carried by wider lateral throws of the needle, any wellknown or other suitable device may be employed either to accelerate and retard the loop-taker or to bodily shift the loop-taker laterally in timed relation with the needle.

It is also to be understood that the timing adjustments of the feed-controlling eccentric 88 do not interfere with the proper feeding of the work, because the timing of the rocking-member 68 to actuate the feed-dog I1 and the timing of the feed-lift mechanism is unaffected by said timing adjustments of the feed-controlling eccentric 86.

Having thus set forth the nature of the invention what I claim herein is:

1. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a feeddog, actuating mechanism for imparting operative work-advancing movements to said feeddog, a rotary feed-controlling eccentric in addition to said actuating mechanism, means actuated by said eccentric and operatively connected to said actuating mechanism for controlling the eflective action thereof, and means for rotating said eccentric continuously in one direction. I i

2. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a feeddog, actuating mechanism for imparting operative work-advancing movements to said feed-dog,

a rotary .feed-controlling eccentric in addition to said actuating mechanism, means actuated by said eccentric and operatively connected to said actuating mechanism for controlling the direc-- tion of feed of the work, and driving means for rotating said eccentric continuously in one direction.

3. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a rotary needle-reciprocating shaft, operative connections with said shaft for reciprocating said needle, a feed-dog, actuating mechanism for imparting operative work-advancing movements to said feeddog, a rotary feed-controlling eccentric operatively connected to said actuating mechanism, and means for rotating said eccentric at onethird the speed of rotation ofsaid needlereciprocating shaft.

4. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a feeddog, actuating mechanism for imparting operative work-advancing movements to said feeddog, a rotary feed-controlling eccentric, means actuated by said eccentric and operatively connected to said actuating mechanism for controlling the direction of feed of the work, and

means for rotating said eccentric in timed relation to successively feed the work twice forwardly and once backwardly.

5. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a workadvancing feed-dog, a feed-bar carrying said feed-dog, feed-advance and feed-lift mechanisms connected to'said feed-bar and effective to im part work-feedingmovements to said feed-dog, a rotary feed-controlling eccentric, means actuated by said eccentric and operatively connected to said feed-advance mechanism for controlling the work-advancing action of said feed-dog, and driving means for rotating said eccentric continuouslyin one direction.

6. In a sewing machine, stitch-forming'mechanism including a reciprocatory needle, a feeddog, actuating mechanism for imparting operative work-advancing movements to said feed 1 8. tion to said actuating mechanism, means actuated by said eccentric and operatively connected to said actuating mechanism for controlling the direction of feed of the work, driving means for rotating said eccentric continuously in one direction, and means providing for adjusting the timing of said eccentric.

I. In a sewing machine, stitch-forming mechanism including a. reciprocatory needle, a feeddog, a feed-bar carrying said feed-dog, feedadvance and feed-lift mechanisms connected to said feed-bar and effective to impart workfeeding' movements to said feed-dog, a rotary feed-controlling shaft, driving means for rotating said shaft, a feed-controlling eccentric, manually adjustable means for securing said eccentric for rotation with said shaft in differently timed positions of said eccentric, and meansactuated by said eccentric and operatively connected to said feed-advance'mechanism for controlling the work-feeding action of said feed- (E. 1 V I 8. m-a sewing machine, stitch-forming mechanlsmg'including a reciprocatory needle, a rotary needle-reciprocating shaft, voperative connections with said shaft for reciprocating said needle, 9. feed-dog, a feedbar carrying said feed-dog, feedadvance and feed-lift mechanisms connected to said feed-bar and effective to impart work-feeding movements to said feed-dog, a rotary-feedcontrolling shaft, driving means for rotating'said feed-controlling shaft at a feed-controlling shaft in slower speed than the speed of rotation of said needle reciprocating, f shaft, an eccentric, manually adjustable means L35 for securing said eccentric 'forrotaticn-vwithsaid. differently timed p0si a rotary feed-controlling eccentric in addiguideway,

11. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a feeddog, a feed-bar carrying said feed-dog, feed-lift actuating mechanism operatively connected to said feed-bar, a feed-advance rocker operatively connected to said feed-bar, a rocking member provided with a guideway, means for rocking said member, a slide-block shiftably disposed in said guideway and connected to said feed-advance rocker to impart feeding and return movements to said feed-dog, a rotary feed-controlling eccentric, a strap embracing said eccentric and operatively connected to shift said slide-block in said eccentric continuously in one direction.

I 12. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a feeddog, a feed-bar carrying said feed-dog, feed-lift actuating mechanism operatively connected to said feed-bar, a rocking member provided with a guideway extending across the fulcrum-axis of said member, means for rocking said member, a slide-block shiftably disposed in said guideway and operatively connected to said feed-bar to impart feeding and return movements to said feeddog in an off-center position of said slide-block in said guideway, a rotary feed-controlling eccentric, a strap embracing said eccentric and operatively connected to shift said slide-block in said guideway from one to the other side of the fulcrum-axis of said rocking member, and driving means for rotating said eccentric continuously in one direction.

" v 13; In a sewing machine, stitch-forming mechtions of said eccentric, and means actuated by T 9. In a sewing machine, stitch-forming mach-- anism including a reciprocatory needle, a feedsaid eccentric and'operativelyconnected to said dog, actuating mechanism for imparting operative work-advancing movements to said feed-dog,

coaxially disposed feed-controlling shafts, driving connections with one of said shafts for rotating the same, an eccentric carried by the other of said shafts for rotation therewith, manually releasable coupling means connecting said shafts for unison rotation and providing for changing the timing of said eccentric with respect to said driving means, and means. actuated by said eccentric and operatively connected to said feeddog actuating mechanism for controlling the work-feeding action of the feed-dog.

10. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a feeddog, actuating mechanism for imparting operative work-advancing movements to said feed-dog, coaxially disposed feed-controlling shafts, driving connections with one of said shafts for rotating the same, an eccentric carried by the other of said shafts for rotation therewith, relatively movable coupling-disks carried by said shafts, one of said disks having a coupling-pin and the other of said disks having a plurality of circumferentially disposed apertures adapted to receive said coupling-pin, yielding means normally holding said disks in coupled engagement and providing for relatively turning said shafts to adjust the timing of said eccentric, and means actuated by said eccentric and operatively connected to said anism including a reciprocatory needle, 9. feeddog, a feed-bar carrying said feed-dog, feed-lift actuating mechanism operatively connected to said feed-bar, a rocking member provided with a guideway extending across the fulcrum-axis of said member, means for rocking said member, a slide-block shiftably disposed in said guideway and operatively connected to said feed-bar to transmit the rocking movements of said member to said feed-dog in an off-center position of said slide-block in said guideway, a feed-controlling element operatively connected to shift said slideblock in said guideway from one to the other side of the fulcrum-axis of said rocking member, and

feed-dog actuating mechanism for controlling the work-feeding action of the feed-dog.

means for actuating said feed-controlling element in timed relation to the rocking movements of said member to impart successively two forward and one backward work-feeding movements to said feed-dog.

14. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a feeddog, a feed-bar carrying said feed-dog, feed-lift actuating mechanism operatively connected to said feed-bar, a rocking member provided with a guideway extending across the fulcrum-axis of said member, means for rocking said member, a slide-block shiftably disposed in said guideway and operatively connected to said feed-bar to transmit the rocking movements of said member to said feed-dog in an off-center position of said slide-block in said guideway, a rotary feed-controlling element operatively connected to shift said slide-block in said guideway from one to the other side of the fulcrum-axis of said rocking member, and driving means for rotating said feed-controlling element once for three complete rocking movements of said rocking member.

15. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a rotary needle-reciprocating shaft, operativ connections with said shaft for reciprocating said needle, a

and driving means for rotating said work-advancing feed-dog a feed-bar carrying said feed-dog, a rocking member provided with a segmental guideway extending across the fulcrum-axis of said member, means for rocking said member in opposite directions once for each complete reciprocation of said needle, a slideblock shiftably disposed in said guide-way and operatively connected to said feed-bar to transmit the rocking movements of said member to said feed-dog, a rotary feed-controlling shaft, means for rotating said feed-controlling shaft at one-third the speed of rotation of said needlereciprocating shaft, a feed-controlling eccentric secured for rotation with said feed-controlling shaft, and a strap embracing said eccentric and operatively connected to shift said slide-block in said guideway across the fulcrum-axis of said rocking member.

16. In a sewing machine, stitch-forming mechanism including a reciprocatory needle, a rotary needle-reciprocating shaft, operative connections with said shaft for reciprocating said needle, a work-advancing feed-dog, a feed-bar carrying said feed-dog, a rocking member provided with a segmental guideway and having a fulcrum-axis intersecting said guideway, means for rocking said member in opposite directions once for each complete reciprocation of said needle, a slideblock shiftably disposed in asid guideway and operatively connected to said feed-bar to transmit the rocking movements of said member to said feed-dog, a rotary feed-controlling shaft extending crosswise of said needle-reciprocating shaft, means for rotating said feed-controlling shaft once for three rotations of said needle-reciprocating shaft, a feed-controlling eccentric secured for rotation with said feed-controlling shaft, and means actuated by said eccentric and operatively connected to shift said slide-block in said s'uideway.

FREDERIC M. CARD.