US2154396A

US2154396A - Feeding mechanism for sewing machines

Info

Publication number: US2154396A
Application number: US176190A
Authority: US
Inventors: Andrew B Clayton
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1937-11-24
Filing date: 1937-11-24
Publication date: 1939-04-11
Anticipated expiration: 1956-04-11

Description

wifne 65 Ap'i'il 11, 1939. A. B. CLAYTON I 2,154,396

FEEDING MECHANISM FOR SEWINGMACHINES Filed Nov. 24, 1937 3 Sheets-Sheet 1 Andrew B. Cla yion April 11,1939. A. B. CLAYTON 5 FEEDING MECHANISM FOR SEWING MACHINES Filed Nov.- 24, 1957 SSheets-Sheet 2 a i x April 11, 1939. AB. CLAYTON 2,154,396.

FEEDING MECHANISM FOR SEWING MACHINES Filed Nov. 24', 1937 s Sheets-Sheet 3 Patented A r. 11, 1939 UNITED STATES PATENT -OFFlCE FEEDING MECHANISM FOR SEWING v MACHINES Andrew B. Clayton, Union, N.J., assignor to The Singer Manufacturing Company,

Elizabeth,

,N. J., a corporation of New Jersey Application November 24, 1931, Serial No. 176,190

9 Claims. (01. 112-214) g This invention relates to feeding mechanism for sewing machines, more particularly of the type having a main four-motion feed-dog the action of which is assisted by an auxiliary'feedmember which may be a step-by'-step driven puller feed-roll arranged in rear of the feed-dog.

Machines ofthis type are commonly used forwhile the machine is sewing, to simultaneously" and equally adjust both the main feed-mechanism and the auxiliary puller feed-mechanism of the machine, so that the stitch-length determining means of the machine are under the constant control of the operator, without stopping the machine or-interfering with the normal v and proper operation of the auxiliary feed-mechanism as an aid to the main orfour-motion feedmechanism of the machine. I

With the above and other objects in view, as

.will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter, set forth and illustrated in the accompanying drawings of a. preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

i In the accompanying drawings Fig. 1, a front end elevation of a sewing machine embodying the invention. Fig. 2 is a plan view of the machine bed and the mechanism mounted thereon. Fig. 3 is a rear elevation of the parts shown in Figs. 1 and 2. Fig.-4'is a section on the line" 4-4, Fig. 2, looking toward the right or in the v direction of. the arrows. 'Fig. '5 is a section on .the same line 4-4 but looking in the opposite direction. Fig. 6 is. a section on the line 6-6,

i Fig. 3. Fig. '7 is a section on the line 1-1, Fig. 3;

Fig. his a disassembled perspective view of the main feed-adjusting lever and parts associated. therewith and Fig. 9 is a; disassembled perspective view of the puller feed-adjusting lever and parts rocatory needlebar 4 and spring-pressed presser- "bar 5. The needle-bar! carries the two needles 6 which cooperate with the usual thread-carrying loopers 1' actuated by suitable mechanism driven by the main shaft 8..

The main feeding mechanism of the machine 5 comprises thefour-motion feed-dog 9 which is carried byv the feed-bar Ill fulcrumed at H on the upstanding'feed-rocker l2. The feed-rocker i2 is pivoted on the lower fulcrum-pin I3 and is formedat one end with a curved, upwardly ex- 10 tending arm. l2, Figs. 2 and 3, having cut thereinthearcuate slot II for the slide-block. l5 carried by the eccentric portion l6of the pin I? which .is clamped between its ends by the split end ID of the pitman l9 embracing the conventional 16 adjustablemain feed-eccentric 20 on the main shaft l. The pin il maybe rotatably adjusted in the pitznan I8 to centralize the feed-dog 9- longitudinally of the usual feed dog slots 9 in the throat-plate 9 I go Obviously, as the slide-block l5 andpin H are shifted upwardly along the arcuate slot is in the feed-rocker extension 127,- the feeding stroke of the feed-dog 8 is shortened. In the present machine, treadle-controlled means are provided for making this adjustment at will without stopping the machine.

To this end there is provided a lever 2| having a double-forkedend 22 which straddles the split end ll of the pitman l8 andembraces the pin I1. The lever 2| has a hub 2| which is journaled to tum freely uponthe puller-feed shaft 23 supported in bearings 24 on the auxiliary bed-casti 25 screwed to the rear side of the main bed casting I. clamped upon the'hub 2| of the lever 2| is the lever-arm 26 which extends rearwardly' of the machine and is connected at its free end by a link 21 to a. treadlc-controlled lever 28 fulcrumedat 2! on the machine bed. .The treadle-controlled lever system ii, 28, 21, 28 is biased in a direction 40 to carry the pin 1 I toward the fulcrum I3 01' the feed-rocker l2 (long-stitch position) by a coilspring 38 which is connected at its upper end to the lever II and at its lower end to an anchorage 3| on the auxiliary bed-casting 25. The chain 32 depending from the lever 2' is to be connected to the usual foot pedal. "By the means described, the operator may instantly adjust the feed-stroke of the'main teed-dog 8 to and maintain it at any desired value, within the limitsprovidedywhfle the machine is in operation.

Mounted on the puller-feed shaft 23 is a puller teed roll 83 which is as usual, behind the main feed-dog 9 and in line therewith, so as to engage and pull the rearwardly from under the usual resser-foot 34 carried by the presser-bar 5. 4

The feed-roll 33 cooperates with the free presse'r-roll 35 which is fixed to the shaft 35 journaled in the yoke 31 fixed to the spring-pressed presserbar 38 mounted in the bracket 39 screwed to the frame-head 3. The presser-bars 5 and 38 may be manually lifted, for introduction or removal of work, by the usual handllfter levers 40, ll, respectively; the latter having a latch 42 which engages a corner shoulder 43 on a frame-plate 44, to hold the presser-roll 55 in elevated position.

The puller feed-shaft 231s given a step-by-step rotary motion by means of the conventional adjustable feed-eccentric 45 on the main shaft 8.

This eccentric is connected by a pitman 45 to a slotted crank-arm 41 depending from the live oscillatory clutch-roll spider 45, Fig. 6, loose on the shaft 23 and having a clutch-roll-carrying portion entering a clutch-cavity 48, Fig. 3, in one end of the cylindrical member fast to. the shaft 23. A stationary anchor clutch-roll spider 5! fast to the bearing bushing 52 hasan anchor clutch-roll-carryihg portion entering a cavity 53 in the other end ofthe cylindrical member 50, The stationary spider 5| has depending from it a rigid arm ,54 the forked lower end of which embraces an anchor block 55 fixed to the auxiliary bed 25. The mechanism of .the live and stationary clutch-roll spiders 48, 5|, with the intermediate cylindrical member having clutchroll cavities in its opposite ends, is the convene tional puller-feed operating clutch disclosed, for example, in U. S. Patent No. 1,980,603, dated Nov. 13, 1934. Heretofore, however, the adjustable eccentric 45 on the main shaft was the sole means of varying thev length of feed of the pullerfeedroll. To make this adjustment it was necessary to stop the machine.

According to the present improvement the connection between the pitman 45 and puller-clutch crank-arm 41 is a variable one and is controlled by the same treadlemechanism which controls the stroke of the main feed-dog. To this end, the pitman 46 has clamped in its rearward split end a cross-pin 56 which is supported and guided by the slots 51 in the lever 28 which has formed integral therewith a cheek-piece 28' spaced laterally from the main body of such lever and containing one of the slots 51. The cross-pin 55 carries a 'sliderbl'ock '58 which works in the arcuate slot 59 in the puller-feed-operating crank-arm 41.

Thus the puller feed-stroke will be greater when the pin 56 occupies a position nearer the axis of the shaft 23. A pull on the treadle chain '32 simultaneously actuates the levers 28 and 2| and carries the cross-pins 55 and I! to the respective positions shown in dotted lines in Figs.-

4 and 5. This shortens the feed-stroke or movement of both the main feed-dog 5 and puller feed-roll 33. The two feed-

eccentrics

25 and 45 are independently adjustable enabling the feeding movements of the feed-dog and puller feedroll to be substantially equalized for the long stitch position of the parts (full lines Figs. 4 and The parts of thetreadle-controlled feedadjustlng mechanism are so proportioned that the feed-strokes of the main feed-dog and puller ,feed-rollare maintained substantially equal to each other in any position of the feed-adjusting lever 28.

' Thus both feeds may be simultaneously and equally adjusted bymeans under the control of arouse the operator, without stopping the machine. Short stitches may be" readily applied at will to the beginning and endingor' other desired portions of a seam, and the original set stitch-length restored at a moment's notice.

As shown in Fig. 1, the main shaft 8 carries the usual feed-lift eccentric 60 which is embraced by the strapped end 6| of the feed-lift pin 62 slidably received in a bore in the feed-bar l0.

The adjusting lever system H, 25, 21, 28 constitutes' means interconnecting the pitmen l9 and 45 to adjust them simultaneously along the slots i4, 59 in the respective crank-arms H, M to which they are connected.

The two

eccentrics

20 and 45 are so set or timed upon -the main shaft 8 as to impart simultaneous feed-impulses to the feed-dog 9 and feed-roll 38.

The invention is not to be understood as limited to the details of construction and relative arrangements of parts of the particular embodiment of the invention chosen for the purposes of the present disclosure. The foregoing specification is to be read as illustrative of and not in limitation of the invention which may obviously be embodied-in many specifically different forms within the spirit and scope of the invention.

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

l. A sewing machine having stitch-forming mechanism, a main shaft, a main feeding mechanism including a four-motion feed-dog, auxiliary puller feed-mechanism including a puller feedwork-feeding speeds of-said feed-dog and pullerfeed roll, without stopping the stitch-forming mechanism.

2. A sewing machine having stitch-forming mechanism, a main shaft, an adjustable main feed eccentric thereon, main feeding mechanism receiving its feed-stroke movements from said eccentric, auxiliary. feed-mechanism, a second and independently adjustable eccentric on said main-shaft connected to actuate said auxiliary feed-mechanism in step with the main feeding mechanism, and manually controlled means exclusive of and additional to saideccentrics and operable without stopping the machine to simultaneously varythe work-feeding movements of said feeding mechanisms.

3.'Feeding mechanism for sewing machines comprising afe'ed-dog, a feed-bar carrying said feed-dog, a feed-rocker to which said feed-bar is pivotally connected, a slotted crank-arm connected to said feedrocker, an eccentric-driven pitman connected to said slotted crank-arm, a

puller feed-roll, a feed-roll-actuating clutch having a slotted crank-arm to actuate it, an eccentric driven pitman connected to the slotted crank-arm, of said puller feed-clutch, and adjusting means interconnecting said pitmen to adjust' them simultaneously along the slots of the respective crank-arms to which they are connected.

4. In feeding mechanism for sewing machines, the combination with two work-engaging feedelements, of means to impart simultaneous stepby-step work-feeding movements to said elements including means to adjust the amplitude of the work-feeding movement of each of said elements relative to the other, and means tosimultaneously and equally vary the amplitude oi the work-feeding movements of both ofsaid elements.

5. The combination with a main four-motion feed-mechanism, of a step-by-step driven puller 5 feed-mechanism, adjusting means to substantially equalize the work-feeding movements of said mechanisms, and other means to simultaneously and equally alter the work-feeding move- 'ments of. said mechanisms, while said mecha- 10 nisms are in motion.

- 6. The combination with main and puller-feed mechanisms anda main shaft connected to, drive said mechanisms, of means to substantially equalize the workfeeding speeds of said mecha- 15 nisms, and means to simultaneously alter the work-feeding speeds of said mechanisms relative to the speed. of said main shaft while maintaining-the substantial equality of said work-feeding speeds.

0 IJ'I'he combination with a four-motion feedmechanism, of a puller feed-mechanism substantially equalized and synchronized therewith,

a main shaft connected to drive said feed-mechanlsms, and means to simultaneously and equally receiving its feed-and-return movements from one of said feed-eccentrics, a puller feed-roll receiving its feed-movements from the other of said eccentrics, and means under the control of the operator to simultaneously and instantly change the amplitudes of the feed movements of said feed-dog and puller feed-roll, while the main shaft continues to run at its full normal operative speed. v

9. In a sewing machine, a main shaft, fourmotion and puller feed-mechanisms actuated thereby, independent adjusting means to vary the work-feeding speeds of each of said mecha nisms, and other means to simultaneously vary the work-feeding speeds of said mechanisms while the speed of the main shaft remains constant. ANDREW B. CLAYTON.