US2376648A - Sewing machine - Google Patents

Description

T. A. ANDERSON SEWING MACHINE Filed May 28, 1943 Maylzz, 1945.

3 Sheets-Sheet l` ZF 31m/vento@ `Mmmmndemon Sito: mun-1A TVA'. 21g@ May 22, 1945.

vT. A. ANDERSON SEWING MACHINE s sheets-sheetl 2 Filed May 28. 1943 May 22, 194:5 T. A. ANDERSON 2,376,648

SEWING MAGHINEv Filed May 2B, 1945 3 Sheets-Sheet 3 @bro/maj Patented May 22, 1945 SEWING MACHINE Thomas A. Anderson, Hartwell, Ga., assigner to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application May 28, 1943, Serial No. 488,808

(Cl. ML2-219) 26 Claims.

This invention relates to sewing machines and has for its primary object to provide means whichV facilitate bringing the needle or other part o-f the sewing machine mechanism into a predetermined position of rest.

In power-driven sewing machine installations, in which the starting and stopping of the sewing machine mechanism are both operator-controlled, the mechanism may come to rest in various different positions of the needle, take-up, etc. For reasons such as to permit shifting of the work from one position to another, or for turning the work about the needle, or for insuring that the take-up is at the upper end of its stroke before restarting the machine, it has heretofore been the common practice of operators to grasp the hand-wheel of the machine and to turn it to bring the actuating mechanism of the machine into the desired position thereof. This prior prac-I tice has resulted in a substantial loss of time and therefore in production.

` Various expedients have hitherto beenA devised for overcoming the above noted condition, such as stop-motion devices designed to stop the sewing machine in a predetermined position each time that the power is disconnected from the machine. These prior stop-motion devices are unadapted for use with sewing machines of the higher speed types, because of the strains to which the parts are thereby subjected each time that the machine is stopped. In many sewing machine operations the runs are short and the parts do not need to come to rest in any particular position thereof. Consequently, when employing stop-motion devices which arrest the sewing machine mechanism in a` predetermined position thereof each time that the power is disconnected from the machine, the mechanism of the sewing machine is in many cases unnecessarily subjected to frequent shocks and strains.

The present invention has therefore for a iurther object to provide improved means facilitating bringing the sewing machine mechanism at will into a predetermined position of rest,'whi1e permittingconventional control of the operation of the machine at other times.

The invention has also for its object to provide means insuring a predetermined position` ofrest of a sewing machine mechanism when the presserfoot ofv the machine is lifted from the work.

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

The invention `comprises the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawings, which illustrate an embodiment of the invention and in which:

Fig. 1 is a rear elevation of a power-driven sewing machine installation containing the present improvement, the supporting table and the treadle-connections being partly broken away. Fig. 2 is an enlarged front elevation, partly in vertical section, of the sewing machine. Fig. 3 is a fragmentary-front elevation, partly in section, of the belt-pulley end portion of the sewing machine. Fig. 4 represents an enlarged, substantially vertical section. of the arm-shaft and its bearing on substantially the line 4 4 of Fig. 2,

and shows in side elevation the driven disk1 the' trip-ring and the trip-ring supporting arm with its bracket detached from the machine. Fig. 5 represents an enlarged vertical section of the armshaft on Substantially the line 5-5 of Fig. 2 and shows the driving pulley in side elevation as viewed from the driven disk side thereof. Fig. 6 illustrates, in perspective, the driven disk, the driving pulley and the pulley retaining means in disassembled relationship and detached from the machine.

Thepower-driven sewing machine installation shown in the accompanying drawings comprises a table ID, upon which is supported a sewing machine I l, and to the under side of which table is suitably secured a treadle-controlled electrictransmitter I2 and presser-lifter knee-shift means The sewing machine II has the usual frame including a bed-plate I4, from one end of which rises the standard I5 of a hollow bracket-arm I6 overhanging the bed-plate and terminating in a head IT.

The bracket-arm I6 has a cylindrically segmental frame-boss I8 supporting a bearing-bushing I9, A rotary actuating or needle-reciprocating shaft 20 has one end portion thereof journaled in the bearing-bushing I9; said shaft being additionally journaled at its opposite end in a bearing-bushing 2l and intermediate its ends in a bearing lug 22, both provided within the bracket-arm I6.

The shaft 20 extends into the bracket-arm head I'l and carries a crank-member 23 operatively connected by a link 24 to a needle-bar 25 which is journaledl for endwise vertical reciprocation in the bracket-arm head Il; the lower end of said needle-bar carrying a needle `26. The crankmember 23 is also operatively connected to a needle-thread take-up member 21 for actuating said take-up member in a conventional manner.

vto the upper end of a lifter-rod 33.

Journaled for endwise vertical movement in the bracket-arm head I1 is a presser-bar 28, to the lower end of which is suitably secured a conventional presser-foot 29. The presser-foot 29 is yieldingly urged downwardly, toward the worksupport by,a suitable spring 36. The presserfoot 29 may coact with any usual or suitable work-feeding mechanism to advance the work past the needle. Pivotally mounted upon a fulcrum-stud 3| at the rear side of the bracket-arm I6 to extend lengthwise thereof is a presser-lifter lever 32. One end of the lever 32 is operatively connected in a conventional manner to the presser-bar 28 to lift said presser-barl against the action of the spring 30. For this purpose, the opposite end of said lever 32 is pivotally connected The lower end of the lifter-rod 33 is operatively connected to one arm of a two-armed lever 34 fulcrumed upon a suitable bracket 35 depending from the bed-plate I4- The lever 34 is acted upon by a spring 36 to depress the downwardly curved end of said rock-lever opposite to the lifter-rod 33 end thereof.

The presser-lifter knee-shift I3 comprises a knee-pad 31 adjustably carried by a rod 38 depending from and fulcrumed for swinging movement upon a bracket 39 suitably secured to the under side of the table I0. Supported-:by the bracket 39 for movement with the knee-pad rod 38 is an arm 46 positioned to engage and rock the lever 34, thereby to lift the presser-foot. 29, when the knee-pad rod 38,is swung to the left from the position thereof shown in Fig. 1. The -described presser-lifter device is structurally of conventional form and any other well known or suitable presser-lifter device may be substituted therefor.

The electric transmitter I2 shown in the drawings is more fully disclosed in the U. S. patent of H. J. Goosman, No. 2,048,501, July 21, 1936. This transmitter provides power means in the form of an electric-motor 4I for rotating a combined clutch-member and iiy-wheel 42. Complemental to the clutch-member 42 is a combined clutch-member and belt-pulley 43 adapted to be axially shifted into and out of clutching engagement with the clutch-member 42. For this purpose, there is provided a yclutch-lever 44 fulcrumed between its ends upon an arm 45 extending from the frame of the electric-motor 4I. One arm of the clutch-lever 44 is disposed to engage the hub of the clutch-member 43; and connected to the other arm of said clutch-lever 44 is a lengthwise adjustable treadle-rod 46 connected for actuation by a suitable treadle 41. The clutch-lever 44 carries a brake-shoe 48 adapted to engage the periphery of the clutchmember 43 under the action of a spring 49, which spring at the same time functions to retract the clutch-lever 44 from effective engagement with the clutch-member 43.

The clutch-member 43 is connected by a belt 50 to a belt-pulley 5I comprising the driving member of the sewing machine. The belt-pulley I is journaled for rotation coaxially of and relatively to the needle-reciprocating shaft 20. To this end, the belt-pulley 5I is freely journaled upon the hub 52 of a driven disk-member 53 secured by screws 54 to the shaft 20 for rotation therewith. The belt-pulley 5I is held upon the shaft 20, in close proximity to the disk-member 53, by a screw 82 threaded into the end of the shaft and by a washer 83 interposed between the head of the screw 20 and the pulley 5 I.

The face o1 said belt-pulley proximate to the disk-member is cut away to provide concentric inner and outer flanges 55 and 56. The inner flange 55 defines an axial pulley-cavity 51 in which is housed a torque-transmitting coil-spring' 58. The inner end of the coil-spring 58 is anchored in a slot 59 formed in the hub 52 of the driven member, while the outer end 0f said coilspring is anchored in a selected one of a plurality of notches 60 formed in the inner pulley-ange 55. The spring 58 is coiled in a direction so that the spring becomes more tightly wound upon rotation of the belt-pulley 5I relatively to the diskmember 53 by means of the electric-transmitter I2; it being understood that the Abelt-pulley 5I is rotated in one direction only by the electrictransmitter. When the spring 58 becomes wound to an extent sufficient to overcome the inertia of the sewing machine mechanism, said spring will transmit to the shaft 20 a rotation-torque which will result in rotation of the shaft 20 in unison with the belt-pulley 5I.

The spaced belt-pulley anges 55 and 56 deiine therebetween an annular recess 6I providing clearance for a buffer-element 62 carried by and extending from the side face of the disk-member 53 proximate to the belt-pulley 5I. A complemental buffer-element 63 is carried by the beltpulley 5I to extend across the recess 6I, thereby to arrest 'movement of the buffer-element 62 in the recess 6 I. Upon rotation of the belt-pulley 5I relatively to the disk-member 53 and in the power-driven direction thereof illustrated by an arrow in Fig. 5 of the drawings, the buffer-element 63 will be initially carried clockwise away,

from-the buffer-element 62 and may ultimately engage said buffer-element 62 from the opposite .side thereof. It is possible, dependent upon the inertia of the sewing machine mechanism and the acceleration speed of the belt-pulley 5I, that rotation of the shaft 20 by the torque action of the spring 58 may be induced before the bufferelement 63 engages the buffer-'element 62; it being understood that the initial tension of the spring 58 may be regulated by anchoring the outer end of said spring in different ones of the pulley-notches 60. In any event, the described comp-lemental buffer- elements 62, 63 limit the extent to which the spring may become tensioned by rotation of the belt-pulley 5I; said buffer-elements at the same time providing a positive drive for the shaft 2D. The increasing tension imposed upon the spring 58 by rotation of the belt-pulley 5I relatively to the shaft 20 tends to minimize buffer-element engaging shock by reason of the shaft-rotating torque transmitted by the tensioned spring.

Recovery of the spring 58 from the imposed torque-transmitting tension is normally prevented by operator-controlled releasable latching means. To this end, the rim of the outer pulley-flange 56 is provided with a circular series of ratchet-teeth 64 concentric with the shaft 20. The ratchet-teeth 64 are engaged by a latchmember in the form of a latch-lever 65 which eX- tends through an arcuate slot 66 formed in the disk-member 53; said latch-lever 65 being mounted upon a pivot-screw 61 threaded into the disk-member, whereby the latch-member is supported for rotation with said disk-member. The tail of the latch-lever 65 at the bracket-arm side of the disk-member 53 is engaged by a spring 68 to urge the lever-nose at the opposite side of. said disk member into engagement with the ratchet-teeth 64.

Encircling the frame-boss la andA therefore` surrounding the shaft 2l),` is a. latch-releasing trip-ring 69 supported for bodily` movement lengthwise of the shaft 20 from a spring-retracted position andV into engagement with the latch-lever' S5 in any angular position of rotation ofV said latch-lever about' the `shaft 20. The tripring 63 is carried by the upper end ofan upright supporting-arm lll; of which the lower end is pivotally mounted upon a screw 1| threaded into a bracket l2; a clearance-slot 'I3 being' provided in the bracket l2 for the lower end of the arm T0. The bracket 12 `is secured by a screw 14 to a recessed seat provided in the bracket-arm standard |5. The supporting-arml is yieldingly biased by a spring l5 into a position in' which the trip-ring 69 is retracted from the latch-lever E5.

Fulcrumed upon the rearward side -of the* frame-boss I8, by a screw 15, is a trip-ring shifting lever l1. One arm of the lever 'l1 is positioned for engagement `with the trip-ring |55l thereby to swingthe supporting-arm 'lll in a direction to carry said trip-ring into tripping engagement with the latch-lever 65. The other arm of the lever 'Il is connected by a spring 'I8 to anVV disk-member 53, the tensioned spring 53 is free to exert upon the shaft a torque tending to rotate or to turn said shaft '20 in the direction of rotation of said shaft with the pulley 5 I; it being understood that the pulley 5| is at this time held against rotation by the elet'cric-transmitter brake 48 acting through the belt 50.

The upper end of the supporting arm 10 is suitably provided with a stop-element E0, and the disk-member 53 carries a stop-element 8| for rotation with the disk-member and therefore with the shaft ZB. InA the operator-actuated movement of the supporting arm 1U to trip the latchlever 65, the stop-element 80 will be brought into the path of rotation of the stop-element 8|, The shaft 20 will therefore be brought to rest in a predetermined position of the needle 2E and of the take-up member 2l. The stopping position of the shaft 28 will, of course, be dependent upon y the location `of the stop-element 80 angularly of the disk-member 53.

From the foregoing description, it will be understood that upon actuation by the operator' of the treadle 4T to release the electric-transmitter brake 48 and to effect rotation of the clutchmember 43 with the motor-driven clutch-member 42, the belt-pulley 5I will be driven by the belt 50. Initially, the belt-pulley 5| will be rotated relatively to the disk-member 53 which is fast' on the shaft 20, owing to inertia of the sewing machine mechanism. In said initial rotation of the belt-pulley 5|', the torque-transmitting spring 58 becomes wound more tightly, thereby imposing on the spring 58 a tension which is sufficient to effect rotation ofthe shaft Zin unison with the' belt-pulley 5|; This winding of the" spring 58 may be limited bythe complemental buffer-ele- `ments 62, (i3 which', thereafter, may' function positively to rotate the shaft 2li. 'Recovery-of the spring 58 from thev tension thus imposed' upon it is normally prevented by the latching meansV comprising the` latch-lever 65 carried by the vided uponftne driving puueyf s r.

vThe latchingmeans described and the interbestopped and? thereafter repeatedly started and stopped, under the rcontrol of the operatorand in the conventional manner, without disconnecting the driven member 53 from the driving pulley 5| and without imposing any additional tension upon the springV 58.

Should it be desiredfor any reason to bring the sewing machine mechanism from any stopping position thereof into a predetermined position of rest, the'knee-shiftglB may be atv will operatoractuated to bring the trip-ring 69 into latchreleasing engagement with the latch-lever 65. The spring 58 isthereby rendered free to recover fromthe tension imposed thereupon in the initial rotation of the pulley 5| and, as the pulley 5| is held against rotation by' the belt-connections with the brakedclutch-member 43l of the electrictransmitter I2, the spring 58 transmits a torque to the shaft 20v to turn said shaft in the direction in which the shaft rotates during the operation of the machine. This further turningv movement of the shaft 20 is arrested in a predetermined position of the parts by the engagement of the rotary stop-element 8| with the stop-element 8|); the stop-element 8|)k having been brought into effective position by shifting the trip-ring 69 into latch-releasing' position.

While the trip-ring shifting and stop-element carrying supporting-arm 'l0A is in the present construction operatively connected for actuation by the presser-foot lifter device, it will be obvious that said supporting arm or a functionally equivalent member could be actuated independently of the presser-foot lifter, without departing frornthe spirit and scope of thapresent invention. lnasmuch as the additional turning movement imparted to the shaft 20 to bring it into a predetermined position of rest is in a direction which is the same as when the sewing machine is in operation, the stitch-forming implements are thereby actuated in their normal thread-handling direction.

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

l. The combination with a sewing machine having stitch-forming mechanism including a reciprocatory needle, a rotary needle-reciprocating shaft, and primary operator-controlled means for at will starting rotation of said shaft and for bringing saidshaft to rest in an indeterminate position of said needle, of supplemental operator-controlled means for initiating a further turning movement of said shaft from an intermediate position of rest of the shaft, a rotary stop-element carried to turn with said shaft, and a complemental stop-element shiftable by said supplemental operator-controlledmeans into the path of movement of said rotary stop-element for arresting said turning movement of the shaft in a predetermined position of said needle.

2. The combination with a sewing machine having stitch-forming mechanism including a recipiocatory needle, a rotary needle-reciprocat` ing shaft. and primary operator-controlled means for at will starting rotation of said shaft in one direction and for bringing said shaft torest in an indeterminate position of said needle, of supplemental operator-controlled meansffor initiating driven member 53 and: the ratchet-teeth s4 pm-v a further turning;movexnentof said shaft in the same direction, a rotary stop-element carried to turn with said shaft, and a complemental stopelement shiftable by said supplemental operatorcontrolled means into the path of movement of said rotary stop-element, thereby to arrest said turning movement of the shaft in a predetermined position of said needle.

3. In a sewing machine installation, vthe combination with relatively rotatable driving and driven members of sewing machine actuating mechanism, and power-transmitting means for rotating and for stopping rotation of said driving member, of a torque transmitting spring interposed between said members for effecting rotation of said driven member in unison with said driving member, said spring being connected for effecting a winding thereof upon rotation in one direction of said driving member relatively to said driven member, releasablemeans normally preventing recovery of the wound spring, and means for tripping said releasable means.

4. In a sewing machine installation, in combination, relatively rotatable driving and driven members, power-transmitting means operatively connected for rotating and for stopping rotation of said driving member, a torque-transmitting spring connecting said members for effecting unison rotation of said driven member with said driving member, said spring being connected for effecting a winding thereof upon rotation in one direction of said driving member relatively to said driven member, releasable means for latching said members together and normally preventing recovery of the wound spring, and means for tripping said releasable means, said spring being wound and connected for effecting a further turning movement of said driven member in the same direction.

5. In a sewing machine installation, the combination with relatively rotatable driving and driven members of a sewing machine actuating mechanism, and power-transmitting means for rotating and for stopping rotation of said driving member, of a torque-transmitting spring interposed between said members for effecting rotation of said driven member in unison with said driving member, said spring being connected for effecting a winding thereof upon rotation in one r direction of said driving member relatively to saiddriven member, releasable means normally preventing recovery of the wound spring, means for tripping said releasable means to permit said spring to transmit to said shaft an additional turning movement in the same direction, and stop means for arresting said turning movement of said shaft in a predetermined position of the sewing machine mechanism.

6. In a sewing machine installation, in combination, coaxially journaled and relatively rotatable driving and driven members, power-transmitting means operatively connected for rotating and for stopping rotation of said driving member, a torque-transmitting spring yieldingly interposed between said members for effecting unison rotation of said driven member with said driving member, said spring being connected for effecting a winding thereof upon rotation in one direction of said driving memberrelatively to said driven member, means limiting the extent of winding of said spring, releasable means normally preventing recovery of the wound spring, and means for tripping said releasable means.

'7. In a sewing machine installation, in combination, coaxially journaled and relatively rotatable driving and driven members, power-transmitting means for rotating and for stoppmg rotation of said driving member, a torque-transmitting spring interposed between said members for' effecting rotation of said driven member in unison with said driving member, said spring being connected for effecting a winding Vthereof upon rota-.

tion in one direction of said driving member relatively to said driven member, releasable latching means preventing recovery of the wound spring, operator-controlled means for tripping said latching means, and stop means brought into effective position by said operator-controlled means for arresting rotation of said driven member under the action of the released spring.

8. The combination with a rotary actuating shaft of a sewing machine, of a driving member journaled coaxially of said shaft for rotation relatively thereto, a driven member carried by said shaft for rotation therewith, power-transmitting means for actuating said driving member, a torque-transmitting spring yieldingly connecting said members for effecting rotation in unison of said members, said spring being connected for effecting a winding thereof upon rotation in one direction of said driving member relatively to said driven member under the action of said power-transmitting means, releasable latching v means normally preventing recovery of the wound `9. The combination with a rotary actuating shaft of a sewing machine, of a driving member journaled coaxially of said shaft for rotation relatively thereto, a driven member carried by said shaft for rotation therewith, a shaft-rotating torque-transmitting spring yieldingly connecting said members for effecting a winding of said spring upon rotation in one direction of said driving member relatively to said shaft, releasable latching means normally preventing recovery of the wound spring, and tripping means for said latching means.

l0. The combination with a rotary actuating shaft of a sewing machine, of a belt-pulley journaled coaxially of said shaft for rotation relatively thereto, a driven member carried by said shaft for rotation with said shaft, a torque-transmitting spring yieldingly connecting said beltpulley and driven member for effecting a winding of said spring upon rotation in one direction of said belt-pulley relatively to said shaft, releasablelatching means normally preventing recovery ofthe wound spring, means for tripping said latching means and thereby permitting a further rotation of said shaft under the action of said spring, and` stop means effective to arrest said further rotation of said shaft in a predetermined position.

11. The combination with a rotary actuating shaft of a sewing machine, of a belt-pulley journaled coaxiallyof said shaft for rotation relatively thereto, a driven member carried by said shaft adjacent said belt-pulley for rotation with said shaft, a torque-transmitting spring yieldingly connecting said belt-pulley and driven member for effecting a 'winding of said spring upon rotation in one direction of said belt-pulley relatively to said shaft, coacting buffer-elements carried by said belt-,pulley and driven member for limiting rotation of said belt-pulley relatively to said shaft, releasable latching means normany preventing .recovery of .the wound spring, "means `for tripping said latching means `thereby to .permit a further :rotation .ofsaid shaft in the same direction-under the action of said spring,

.and stop meanseieotive `to, arrest .said further unison rotation of said disk-member with said puHey-mEmbensaid .spring being housed in one .of said .members andzbeing .connected foreffecting a `winding of said spring upon rotation .in one direction of `said `pulley-member relatively to said :disk-member, releasable latohing means normally ipreventing recovery of lthe .wound spring, and [means vfor vtripping said ylatching meansthereby to permit relative rotation of said Amembers under the `action of Said spring.

iffllhe `icorn-bination with a .rotary actuating shaft of .a sewing machine, of a driving member journaled coaxially of said shaft vfor rotation relatively thereto, a ydriven member carried by said shaftadjacent `said driving member forrotation with said shaft, Aa torque-.transmitting spring interposed :betweenv said members for effecting .rotation fofsaid driven member in-unison `with saididriving-mernber, said spring being connected foreffectinga .winding thereof upon rotation infone `direction of said driving rmember relatively .to said vdriven member, rlatching means normally preventing recovery .of the Wound spring, .said latching means lcomprisingia series of ratchet-teeth carried Abylone of said r.members and a spring-pressed latch-,4ever `ca.f'xied.1l.iy the otherof said members `for `engagement with said ratchet-teeth, andk operator controlled Ameans for tripping said llatchelever.

14. in a .sewing machine, in combination, a rotary actuating shaft, la driven member having a hub seoured'upon said shaft for rotation therewith, a `driving member .disposed at .one side lof said driven member and journaled upon'said hub for rotation relatively to said shaft, said driving member having an annular cavity fand being provided at the driven member side thereof with a circular series of "ratchet-teeth, a coil-spring housed in ysaid cavity of `the-driving member, said spring Vhat/ringtone of its ends connected to said driving member and `having its other end connected to the hub of said driven member for transmitting `a shaft rotating-torque -to said driven member upon rotation of said driving member in one direction, alatoh-lever carried bysaidgdriven member for engagement with said ratchet-teeth, and operator-controlled means for tripping said latch-lever.

15. In a sewing machine, in combination, a rotary actuating shaft, a `disk -havinga hub secured upon said shaft -for Irotation therewith, a belt-pulley journaled upon said hub for rotation relatively `to said shaft at one side of said disk, said belt-pulley having a circular series yof ratchet-teeth concentric with said belt-pulley, a coil-spring Vhaving one of its ends connected to said belt-pulley and Vhaving its other end connected to transmit ashaftrotating torque to said disk `upon rotation of said belt-pulley in one direction, coacting buffer-elements carried lbysaid belt-pulley iand elisir permitting `limited initial rotation oi'-said`-beltpulleyrelatively to said shaft ,for effecting :a sanding 0f Said coibsprins, .a

iatale-lever v,carried by :said disk .for iengagement with said :ratchet-teeth ,a direction normally :preventing recovery :of the wound spring, operator-controlled means for tripping said latchllever `in anyangular :Position of rest of lsaid actuating shaft, a 'rotary'.stop-element Acarried by .said disk, and a complemental .stop-element brought into` effectiveY position by `said operatorcontrolledqmeans for-shaft-arresting engagement .by said' :rotary stop-element.

Q16. In a `sewue machine, .in combination, a rotary actuating shaft, a disk `having ahub secured upon said shaft `for ,rotation therewith, a

;cular flanges, vone of said yanges being circumferentiallyprovided with'a-series of ratchet-teeth and the other of said `.flanges `providing an axial .cavityin said :belt-pulley, acoil-.Slorina housed in said cavity of :the belt-pulley and having one of itsendsanohored to saidv vbelt-pulley and hav- .ing .its I.opposite .end .anchored to the hub `of said disk,.a1buffer=element carried v.by .said disk and extendingbetween :theflanges of said belt-pulley, a complemental buffer-element carried by said belt-pulley :for rotation therewith and disposed rtoengage the buffer-element carriedby said disk,

, allatchalever pivotally mounted upon said disk for engagement vwith said ratchet-teeth in a direction normally 4preventing .rotation of said shaft responsively toztheacton of said spring and relatively to saidxpulley, a latchalever tripping ring .surrounding said shaft and supported for movement into and out of .engagement with said llatch-eleven and `manually `operable means for shifting said ring `into tripping' engagement with said latch-lever.

1'7. The combination with a rotary actuating shaft of a sewing. machine, of adriving member Ajournaled coaxially of said shaft for rotation relatively thereto, a driven `member carried by said shaft for rotation therewith, a torque-transmittingspring yieldinglyconnecting said members` for effecting a .winding of said spring upon rotation in one direction of said rdriving member relatively to 'said shaft, releasable means including' `a vlatch-member rotatable with said shaft for normally preventing recovery of the wound spring, and operator-controlled means for releasing said `latchamemherin any angular position of rotation of said latch-member.

18. 'I'he combination with a yrotary actuating shaft of a'sewing machine, of a driving member journaled -coaxially of said shaft for rotation relatively thereto, a driven member carried by said shaft for rotation therewith, a torque-transmitting spring yieldingly connecting said mem `bers for `effecting a winding of said spring upon rotation in-one direction of said driving .member relatively to said shaft, releasable means including a vlatch-member rotatable .with said shaft `for normally .preventing recovery `of the wound spring, a. latch-member releasing tripring V.surrounding said shaft, la-nd operator lcontrolled `means for shifting said trip-ringendwise of said shaft into engagement with' said latchmember.

:19. In a power-driven sewing machine installation including a sewing machine having a needle, land a rotary 'needle-reciprocating, shaft, ypower means, `and a ,clutch-andsbrke .device interposed between said 'power means and said.

after said machine has been brought to rest,y

thereby permitting a further rotation' of said shaft under the action of said spring for needlepositioning purposes.

20. In a power-driven sewing machine installation including a sewing machine having an endwise reciprocatory needle, a rotary needlereciprocating shaft, a work-engaging presserfoot, presser-foot lifter mechanism for disengaging the presser-foot from the work, power means, and a clutch-and-brake device interposed between said power means and said sewing machine for controlling the-operation of said sewing machine, the improvement which consists in the interposition between said clutchand-brake device and said rotary shaft of a torque-transmitting spring with releasable latching means normally preventing recovery of said spring from the tension imposed thereupon in starting rotation of said shaft, operative connections with said presser-foot lifter mechanism for releasing said latching means upon disengagement of said presser-foot from the work, thereby permitting rotation of said shaft under the action of said spring, and stop'means effective upon release of said latching means for arresting rotation of said shaft in a predetermined position of said needle.

21. The combination with a sewing machine having an endwise reciprocatory needle, a rotary needle-reciprocating shaft, a Work-engaging presser-foot, and operator-controlled presser-foot lifter mechanism, of a driving member ,journaled coaxially of said shaft for rotation relatively thereto, a driven fmember carried by said shaft for rotation therewith, power-transmitting means operatively connected for rotating and for stopping rotation of said driving member, a torque-transmitting spring connecting said driven member for rotation in unison with said driving member, said spring being yieldingly connected for effecting a winding thereof upon rotation of said driving member relatively to said driven member by said powertransmitting means, releasable latching means normally preventing recovery of the Wound spring, and means operatively connected to said presser-foot lifter mechanism for releasing said latching means during lifting of said presserfoot.

22. The combination with a sewing machine having an endwise reciprocatory needle, a rotary needle-reciprocating shaft, a ywork-engaging `presser-foot, and operator-controlled presser-foot lifter mechanism, of a driving member journaled coaxially of said shaft for rotation relatively thereto, a driven member carried by said shaft for rotation therewith, power-transmitting means operatively connected for rotating and for stopping rotation of said driving member, a torque-transmitting spring connecting said driven member for rotation in unison with said driving member, said spring being yieldingly connected for effectinga winding thereof upon rotation of saiddriving Amemberrgrelatively to said .driven member lby said power-transmitting means, releasable latching means normally preventing recovery of the Wound spring, means operatively connected for releasing said latching means upon actuation of said presser-foot lifter mechanism, thereby to permit a further rotation of said shaft under the action of said spring, and stop-means effective upon release of said latching means for arresting said further rotation of said shaft in a predetermined position.

23. The combination with a sewing machine having an endwise reciprocatory needle, a rotary needle-reciprocating shaft, a work-engaging presser-foot, and operator-controlled presserfoot lifter mechanism, of a driving pulley journaled coaxially of said shaft for rotation relatively thereto, a driven member carried by said shaft for rotation therewith, power-transmitting connections with said pulley for rotating and for stopping rotation of said shaft, a torque-transmitting spring connecting said driven member for rotation in unison with said pulley, said spring being yieldingly connected for eiecting a winding thereof upon rotation of said pulley under the action of said power-transmitting means, releasable latching means rotatable with said shaft for normally preventing recovery of the wound spring, a latch-releasing trip-ring surrounding said shaft, a support for said ring providing for axially shifting said ring endwise of said shaft, operative connections with said presser-foot lifter mechanism for shifting said trip-ring into latch-tripping engagement with said latching means, thereby to permit further rotation of said shaft under the 'action of said spring, a stop-element rotatable with said shaft, and a complemental stop-element rendered effective upon release of said latching means for arresting rotation of said shaft.

24. The combination with a rotary actuating shaft of a sewing machine, of a driving member journaled coaxially of said shaft for rotation relatively thereto, a driven member carried by said shaft for rotation therewith, a torque-transmitting spring yieldingly connecting said members for effecting rotation of said driven member in unison with said driving member, said spring being connected for producing a winding thereof upon initial rotation of said driving member in one direction relatively to said driven member, releasable latching means normally preventing recovery of the wound spring, a latch-tripping member, operator-controlled means for shifting said latch-tripping member into latch-releasing engagement with said latching means, thereby to permit rotation of said shaft under the action of said spring, a rotary stop-element carried for rotation with said shaft, and a complemental stop-element shiftable by said operator-controlled means into the path of rotation of said rotary stop-element.

25. The combination with a rotary actuating shaft of a sewing machine, of a driving member journaled coaxially of said shaft for rotation relatively thereof, a driven member carried by said shaft for rotation therewith, a torque-transmitting spring yieldingly connecting said members for effecting rotation of said driven member in unison with said driving member, said spring being connected for producing a winding thereof upon initial rotation of said driving member in one direction relatively to said driven member, complemental latchingr means normally preventing recovery of the wound spring andincluding a ,latch-member carried for rotation withsaid shaft, a latch-releasing trip-ring surrounding said shaft, a trip-ring carrying arm pivotally supported for movement'of said trip-ring into and out of latch-releasing engagement lwith said latch-member, a rotary stop-element carried for rotation with said shaft, a complemental stopelernent carried by said arm for movementI into the path of rotation of said rotary stop-element, and operator-controlled means for actuating said arm in a direction to trip said latch-member and to arrest subsequent rotation of said shaft.

26. The combination with a sewing machine having stitch-forming mechanism including a reciprocatory needle, anda rotary needle-reciprocating shaft, of primary power means for effecting rotation of said shaft, primary operator-conelement carried for rotation with said shaft, and

a complemental stop-element shiftable by said supplementaI operator-controlled means into the path of movement of said rotary stop-element.

THOMAS A. ANDERSON.-

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