US1151534A - Stop-motion mechanism. - Google Patents

Description

lA. R. woon.

'STOP MoloN MECH-ANISM.

` APPLICATION FILED JULY 2|. 19|]- Patented Aug. 24, 1915.

2 SHEETS-SHEET 1.

AY R. WOOD.

STOP MOTION MECHANISM.

APPLICATION FILED JULY 21.1911.

` BntentedAug. 24, 1915.

2 SHEEYS--SHEET 2.

.9 7. m/v/Z NK 0 z W 1. 5 5w 9 /4 /U A TTOHWEY UNITED sTATEs :PATENT OFFICE.

4 ALFRED R. WOOD, OF MAMARONECK, ANEW YORK, ASSIGNOR TO THE SINGER MANU- FACTURING COMPANY, A. CORPORATION OF NEW JERSEY.

STOP-MOTION MECHANIsM.

T0 all whom it may concern Be it known that I, AL'FRED R'. WOOD, a. citizen of the United States, residing at Mamaroneck, in the county of Vestchesterv and State .of New York, have invented cer-` ',tain new and useful Improvements in Stop- Motion Mechanisms, of which the following is a specification, reference being had therein to the'accompanying drawings.

This invention relates to an improvement in stop-motion mechanisms, and more particularly to mechanisms of that class designed i'or control of the stitch-forming and feeding devices ofsewing machines for the production of groups of stitches of predetermined number, as in the stitching of buttonholes and in barring and tacking.

The invention has for its primary object to increase the certainty andprecision of action of this class of mechanism.

In they preferred form of the improvement, the rotary shaft to be controlled has fixed thereon a stopping-cam formed with an operative face inclined 'to its directionof movement and terminating in an inwardly extending shoulder, and also provided with a second shoulder disposed in a different plane.

A laterally swinging vstop-lever mountedupon a 'xed fulcrum carries a longitudinal spring-pressed endwise-movable plunger adapted to engage the operative face of said cam and the adjacent shoulder and also a transverse spring-pressed plunger adapted to engage. the second-named shoulder of the cam. The said shaft has fixed thereon a brake-wheel embraced by a friction-band adapted to be tightened upon the brakewheel by a connection with the longitudinal spring-pressed plunger underthe action of the operative face of said cam but to'be slackened when such plunger passes the adjacent shoulder subsequently to the engage-l ment of the second-named shoulder with the transverse plunger by which the shaft is' brought to rest.

' A spring serves to normally press the stop-lever into active positionwherein said plungers are brought into operative relation with the stopping-cam, and the stop-lever *is provided `with a lateral arm connected with a reciprocating operating rod formed with two opposi'tely presented shoulders adapted for ,engagement respectively by a "primary, .detent-lever' .anda secondary de- Specication ofLetters Patent.

a tripping stud upon a feed-cam or other operative part of the machine, while the operating rod carries a tripping device `for the .auxiliary detent-lever to which is attached l Patented Aug. 24,1915. y Application led July 21, 1911. Serial No. 639,746. i

a treadle connection in such manner that the actuation of the treadle causes first the disengagement of the auxiliary detent-lever from lthe operating rod and then the drawf fully by reference -to the accompanyingv drawings, in which- 4 Figure l 1s a rear side elevation of a portlon of a buttonhole stltchingmachine pro- Fig. 2 a plan of the'same. Fig. 3 is a rear tion of the stop-motion mechanism viewed from the front end, and Fig. 5 a sectional side elevation of' the rear end of the machine v and the stop-motion. Fig. 6 is a detail view of the stopping cam and adjacent portions ofthe' angularly arranged plungersin stopping position. Fig. 7 is a detail view of the .lower portion of the operating rod with the tripping member carried thereby. Figs. 8 and 9 are respectively.an edge view and a bottom plan of the operating rod and the meansv Jfor locking the same in its two extreme positions. l

The present improvement 'is shown embodied in a. stop-motion mechanism siliilar in general construction to that forming the subject of the United States patent to H. lV. Slater and J.'T. Hogan, No. 894,073, dated July 21, 1908. The sewing machine frame is shown constructed with the bed-plate l and the bracket-arm comprising the hollow standard Q and the tubular member 3. the standard 2 having the bearing boss 4 containing the bushing 5 in which is journaled the rearward end of the main or drivingl shaft 6 of the machine carrying the fast and loose pulleys 7 and S, respectively.

Secured upon the driving shaft interme-y .vided with the present improvements, and' -end view of the machine, Fig. 4 an elevai stopping-cam comprising the rigidly connected disks 9 and 10. thel former having a .substantially snail-'shaped -periphery 1l terthe brake-strap 42 which is shown provided minating in its outer portion in the in wardly extending shoulder l2 forming. a

step connecting the inner and outer operative portions of the periphery. The disk 10 ing thev alined center screws 20 upon which' is shown provided with a lateral projection 13 having a facing afforded by the forward edge of a hardened block 14 let into a lateral recess in said disk and secured therein by means of a fastening screw 15, the forward edge ofthe block 14 providing a stopping shoulder by means of which the shaft is iina-lly brought to rest. l

The rearward end of the standard 2 is formed with a seat'16 upon which is secured by means of the bolt 17 the foot 18 of a. bracket formed with spaced lugs 19 carryis journaledthe swinging stop-lever 21. The stop-lever is formed with the split bearing boss 22 enteredI by the externally threaded bushing 23 which forms one of the bearings.

. of the i endwise reciprocating plunger 24 whose upperl portion is journaled in the bearing member 25 of the stop-lever and lwhosepupper extremity is adapted'to engage thep'eriphery of the stopping-cam disk 9. The' 4 plunger 24 is normally pressed upward A y oper-ativeengagement with the stoppirigp'am'by means of the spring 26 interposed -betweenthe inner ends of thebushing -23 and the collar 27 adjustably secured upon said plunger within the central aperture 21X i of the stop-leverby means of the lset-screw 28 and provided withv the p rearwardly extending lug 29.

At its rearwardl edge, the stop-lever is'- 'in normal position upon thev stop-lever by.

means of a second spring 38 which is' interposed between the outer extremity or head of the bushing 31 and the adjustable thrustnut l3.9 applied to thefthreaded outer eXtrem-l ity of the plunger .and secured in position by means ofthe lock-nut '40. 'y

Fixed upon the driving shaft 6,l and preferably formed integral'with the stoppingcam, is the brake-whel 41,surrounded by with a facing 43 of soft material such as rawhide, and having one end secured by Y. l'means of screws 44 upon the`lug 45 formed upon one of theears 19 of the stop-lever 35 aording an r threaded to receive the thrust-nut 47 with supporting bracket. The opposite end of the brake-strap is attached to a pull-rod 46 the lock-nut 48 and the thrust-nut 49 with l thumb-nut 50. i

lFulcrumed upon the stud-screw 51 tapped into the lug of the bracket to which one end of the brake-band is attached is alever 52 extending transversely beneath the lug 29 carried by the plunger 24 and .apertured at. its opposite end to receive the pull-rod 46. The outer end of the lever 52` is maintained yieldingly in contact with the thrust-nut 47 by means of a spring 53 interposed between the same and the thrust-nut 49 which latter is adjustable-upon the pull-rod for varying,

`the tension of theY spring. As will be ob` served, the descent of the plunger-bar 24 under the action of the cam edge 11 operates through the engagement of the lug 29 with the lever 52 to draw downwardly the free end of the brake-band so as to produce an additional resistance to arrest the driving shaft in addition to that imposed by the enl i gagement of the plunger-bar 24 upon the cam-disk 9.;

The bushing 23 carries a loose washer 54 .Y

having a perforation entered by one end of a spring 55 whose other .end enters a trans- .verse aperture in a pin 56 depending from the bed-plate, by lmeans of which thestoplever is normally drawn into uprightposition upon its center-screws 20 so as to bring its longitudinal and transverse plunger-rods into operative relation with their respective portions of the stopping-cam. The upper transverse member of the stop-lever has secured thereto by means of the screws 57 the foot 58 of a forwardly extending.' arm 59 to which is secured' byl means of screws 60 the shank 61 of the belt-shipper` 62 adapted to 'register with the fast and loose pulleys re.- v

spectively when the stop-lever is in retracted andjsto-p-ping position. 4

Tlie. forward end of the arm 59 is formed with a slot 63 entered by the cross-pin y64 in the forked upper end 65 of the operating rod 66 journaled in an aperture in the bedplate through which it extends'. The rod 66 has secured thereon beneath the bed-plate by'means of the set-screw 67 the collar 68 shown formed with a flat upper face 69aand with its lower end-provided with a notch 70 at one side ofthe rod' 66. rlhe upper face 69V and-the notch 76 in the lower 'face afford'oppositely presented shoulders for engagement i with the detent-levers by which the rod is locked in upper and lower position, respectively. Upon the .fulcrum-screw 71 depending from the bed-plate is journaled the hub 72 of the main detent-lever havinga rearwardly extending arm 73., adapted for engagement ,f`f v with the upper face 69 o'f the collar 68 and 1 forwardly projecting arm 74 upon which is rar y adjustably secured by means of .screws 75 the plate T6 formed with the laterally projectilig nose TT normally lying within the path ot` 1novement of the tripping pin TS proJec-ting from the upper face ot' the rof tary leed-wheel 79. Secured to the outer edge of the arm-71 by means of the screw' S0 is the flat spring'Sl whose outer portion normally rests in contact with the dependf ing rib 1x of the bed-plate to normally maintain the nose-.piece yielding'ly within the path of movement of the tripping pin7S.

Overlying the detent lever-arm l73 is the auxiliary detent-lever S2 which is fnlcrnmed at one end upon the stiid-screw 71 with its other end continedfwithin the stirrnp 83 secured upon the lever-arm 7 3 by means oiJ the screws ,81. The-lever S2 is normally drawn toward the collar GS by means ot' the spring 85 attached to the same at one end and at the opposite end to the bed-plate rib l", and is adapted to enter the notch 70 in id collar 'ivhose inner wall affords a stop therefor.

The flattened lower end 66 of the rod 66 is formed with a transverse aperture entered by and serving as a bearing for the axial stud 86 of 4the segmental tripping cam-disk STornied upon one side with the wedgeshaped cam portion -SS adapted to engage the beveled edge S2x of the auxiliary de-` tent-lever 82. The camdisk 87 is provided 'opposite the operative 4portion 88 'and near the periphery'with the aperture 89 in ywhich is hooked the upper end of the chain 90-or other connection with a treadle or knee-lever by which the stopmotion is initially actuated. The cam-disk'S is provided with an eye 91 entered by one end' of the spring 92 whose-opposite end embraces the set-screw 67, whereby. the disk is normally maintained with itsl cam ortion SS retracted from the 4detent-lever ,8L and the connection with the i chain' 90 arranged at one sideof the pivotal ,-stiid`86: .The operatine rod '66 has secured T thereto'above the bed-p ate by means of the set-Screw 93 the stop-collar 91 whose eng'agement with the upper face of the bedplate .servesto limit the downward movelment ofthe rod 66 and the forward' retracted movement oli theI stop-lever whose movement in4 theppposite direction under theac- ,A resented n;

tion of its` spring isjarrested' by means of the jaminiit 96..

i f a the-stud' 95 securedl inpositionvby means of `Vhenthe achine is 'at rest; the stop-lever isI in itsuijeai'wa'rd retracted position as repi Eig.l 1, 'theaipperl endV of the plungerbar; 211*- hayvingdropped'4 ot the high point' of 1 thef'fperlpheral -iciini' 11 behind the .-slion'l-derilZ, andxvthe striking member-1l of thev stopping-"cam resting in engagement with thel shoiilder'g'of the'transverse pluri gef-lln1- fi sfifepresegted. inf; '6.l 4Atfthiposition and the auxiliary dctent-lever 82 is in engagement with the operative tace of the notch 'iO-inv thc collar 68,- as represen-ted in Figs. 1., 3 and 8, the tripping cala-disk S7 being maintained in retracted or 1nop'erative position by means ot' the' spring 92. The

drawing down'of the treadle connection 90 causes an initial quarter-turn ot the trip- Y ping cam-disk S7 for engagement ot' the o ierative cam portion SS with the adjacent e ge oit' the auxiliary detent-lever 89. which latter is pressed backwardly in opposition to its spring S5, and after such release ofy the collar GS the continued drawing'down lof said connection causes the descent of the rod 66 and the tilting of the stop-lever into its forward or retracted position, thereby disengaging its plunger-bars from the stopping cam and throwing the belt-shipper to carry the drivin belt from the loose to the fast pulley. Ast e collar 68 reaches its lowest position, the

primary detent-lever snaps over the same anc locks it therein. The machine now continues itsoperation until the feed-cam 79 has' nearly completed a rotation, when its tripping pin 7 S engages the nose'77 of the primary detent-lever and rocks the same in oppositionto its spring S1 to disengage the arm73 from the collar 68,there by permitting it to rise under the action of the stop-lever spring 55 by means of which the stop-lever 1s thrown backwardly into` stopping position with the operative fportions of its plunger-bars disposed within erative edge of the cam-disk 9 which continnes to thrust it' downwardly and under the 4 engagement ofthe lng 29 with the lever 52 to compress the brake-spring 53, thereby. p

yieldingly drawing down the adjacent end of the brake-band and applying with i-ncreasing intensity a lErictional drag upon the brake-wheel Lil. When the stoppingcam reaches a position wherein the shoulder 12 is `above the plunger-bar 2st, as representedl in Figs. 1I to 5 inclusive, the striking block 1-t engages the shoulder 36 of the mo.-

'mentum-absorbing plunger, the shockof such engagement in overcoming the iernaining momentum being taken up by the spring '3i'.v As the cam-shoulder 12 passes the upper., extremity of the plnngei-bar Q4, the lati terf'snaps' behind the same and serves asa stop' to Vpreventithe recoil ofthe stopping- #cam and the main-,shaft under the action of. As the plunger-bar 52-1 rises.

[the Springlfi'..

Iehind the cam-shoulder 12, the pressure of 'Y'tiiner-tlesl ireiatins inv-its., uiier'*fhebrkefpring 53. is relieved and the fic- I tion of the brake ceases; but the operationy the operation lof thecu'shion'-sp ring 37.111

absorbing the remaining momentum of the machine communicated through the stopping-cam. Thus the operation of the diiferent successively acting members in absorbing the momentum of the machine is continuous and thereby insures against the noisy operationof the stop-motion and the injury of the interengaging parts through the-in- A tensity of their impact, which has been a Y serious` defect of 4'certain other constructions. rlhe adjusting means for the brake obviously affords provision for reducingthe momentum vto the required extent for a given speed of rotation of the shaft before the nal action of the transverse plunger-bar.

By timing the parts to effect the engagement ofthe striking block 14 with the shoul-y der 36 of the momentum-absorbing plunger while the shoulder 12 of the cam-disk 9 is still above the end of the upright plunger 24, as represented in Fig. el, the plunger 24 is not permitted to rise for engagement with the shoulder 12 until the buffer-spring 37 has been materially compressed in absorbing the remaining momentum of the mechanism, so that whentlie niachinecomes to rest the stopping cam is held securely against turning in either directionby engagement of the members 11 andi andthe cam-shoulder 12 against the side of the plunger 24.

In throwing the stop-lever for starting the machine, 'before the plungers are wholly retracted from operative relation with the stopping-cam the belt-shipper has drawn the driving belt from the loose pulley partially over upon the tight pulley so was to produce a tendency to turn the main-shaft in opposition to the yielding resistance of the bufferspring 37. Tere the latter not under a considerable tension, this would produce the repeated slipping and` engagement of the belt upon the fast pulley with a corresponding pounding of the interengaging parts of the stop-motion; but in practice the tension of the springs and adjustment of the Various parts is such that the then compressed spring 37 serves to resist the imperfect action ef-Y the belt'to'induce the rotation of the tight pulley until the *interengaging parts of the stop-motion are Wholly disengaged,` when the I operation of the machine is permitted to proceed. 4

It haslong been common heretofore, in`

connection with machines for producing groups ofjstitches of predetermined num-` ber, to provide means for locking the stopmotion in retracted positionduring the performance4 of'a cycle of. operation of they In machines in which the motion-arresting member of the stopping mechanism is thrown by means of a spring into the path of cperation of 'al rapidly moving part to be acted upon thereby, it frequently happens v that continued wear or the'chipping of the 'edges of such parts by continued use pro- .duces avtendency to force the spring-pressed part backwardl'y in opposition to its actuating spring so as tofrender the stop-motion ineffective and produce a liability of breakage.

According to ythe present improvement, the stop-lever is not only provided with the customary locking means yfor maintaining it in retracted position during the normal operation of the machine, but it also has means whereby, when once thrown into` operative or stopping position,l it' is securely locked in such 'position' so as to insure the proper action of the interengaging rotary and non-rotary parts.

In stop-motion'mechanisms employing a plurality of endwise movable springpressed yplungers adapted to be shifted laterally into and out of operative relation with the stopping-cam respectively when f stopping and starting the machine, it has been the practice to grind the upper extremity of the initially acting plunger with an incline having its higher edge on the side toward the stopping-cam, so that when said plunger is thrown into operative relation with'the latter a corresponding slight inoline in thev operative face of such cam in the other direction will insure the effective cooperation of the interengaging "parts Under such conditions, the reaction produced by the brake-spring upon the plungerA has a tendency to throw the sam laterally out of operative relation with the stoppingcam, which causes the operative end of the plunger to become slightly worn. sult only the forward edge of the striking block carried by the cam engages the shoul-l der of the transverse plunger, so that'the edges of both these members become battered and worn after continued use stifliciently to cause the mainshaft of the machine tomake oneormore revolutions after the stop-motion has been tripped, andg thereby repeatedly thrustthe first-named 'plunger out of operative position to be retiirneil-byV its laterally acting spring. Ac-

'cording to the present improvement, these plungers .are both positively locked in operative relation with `the stopping-cam promptly uponbeginning their motionar-resting operation which is completed without the described premature disarrange- `ment of the operative parts.

i--It Will'be readily understoodfthat the As a rethe shaft for locking said p liiiiger `.against lateral-movement rtrom both operative and L means t'or locking the motion-arresting member of the stop-motion in operative relation with the rotary ineml'ier cooperating therewith is not limited to the. embodiment herein shown and-described nor to association with the stop-motion mechanism represented in the accompanying drawing, as itis susceptible ot' construction and arrange-r ment in very diHerent forms and associations within the scope of the present 'invention.

Having thus set forth the nature of the invention, what I claim herein is z- 1. The combination with a driven rotary shatt ,of a stop-motion comprising a rotary member mounted upon and movable with said shaft and having a shoulder transverse to its direction of movement, a motionarresting member adapted to be shifted into and ont of operative position for engagement ywith said shoulder of the rotary member in effecting the starting and stopping of said'shaft, and means acting independently of the rotary movements of the shaft for positively locking said motion-arresting member within the range 'of movement of 'said shoulder, said means acting automatically when the motion-arresting member is shifted into operative position.

:2. The combination with a driven rotary shaft, ot a stop-motion comprising a ro-l tary member mounted upon and movable with said shaft, and having a shoulder transverse to its direction of movement, a-

motion-arresting member adapted to.y be shifted into and out of operative position for engagement with said shoulder of the rotary member in effecting the starting and stoppingof said shaft. means acting automatically and independently of the rotary movements of the shaft for positively locking said motion-arresting member within 4rz nge ofinoveinent of said shoulder, and

'. said rotary member. A

3. A stop-motion comprising a rotary `means for successively rendering ineffective said lockingmeans andl vshifting the arresting member out o f operativev relation with shaft and a stopping cam carried thereby, a laterallyniovable spriiig-presscd plunger ."adapted' Jfor operative uigagenient with said cam, a spring ltor throwing said plunger laterally into opei'ative relation with the I cani, means acting automatically and wholly independently of the rotary movements of inoperative` relation with said cam, automatically acting means for rendering the locking meansineti'efctivevwhile the plunger-L is in inoperative relation with the cam, and L manually controlledlimean's movable independently of the `locking means ineffective whilethe plunger is inoperative relation with the cam.

4. A stop-motion comprising a rotai'y shaft and a stoppingV cam earriedlthereby,`

a swinging stop-lever,- a spring-pressed pli'ine'er for shifting saidstop-lever to carry said plunger into operative relationl with. the' carried by said stop-lever. a spring stopping cam,automatically acting means.l

controlled independently of the :rotary stop-lever 'in extreme positions with said plunger respectively in operative and-inoperative relation with the stopping cam. automatically controlling means `tor unlocking said stop-lever in. one of its extreme positions, and manually controlled means'for unlocking said lever in itsother extreme position.

A stop-motion comprising 4a rotary shaftvand a stopping cani carried thereby. a laterally movable spring-pressed plunger adapted for operative engagement with said cam, a spring for shitting said plunger lat- `movement of said main-shaft for locking rthe erally into operative relation with the cam` and a locking device comprising two springactuated detent levers movable relatively to each other upon a common pivotal support and adapted to automatically and succesf 'sively'loek said plunger against lateral movement from both operative and inoperative relation with said cani.

6. A stop-motion comprising a rotary stopping-cam. a laterally movable springpressed plunger adapted for operative enj gagement with the saine` plunger-shitting means adapted t'or moving the plunger into and out of operative relationwith the stopping-cani and including a reciprocatory element having oppositely presented shoulders.'

to engage said shoulders. and means t'or, operating said detent-levers.

' separate detent-levers respectively adapted i T. A stop-motion comprising a rotary y stopping-cani, a laterally iuovahle springpressed plunger adapted tor operative enmeans adapted t'or moving the plunger into i and 'out ot operative relation with the stoppliinger toi",(reuderingthe tipping-cani and including a recipro vatory element having oppositely,presented shoulders'.

separate detent-levers respectively* adapted 1'3'0" (the other extreme 4 stopping-cam.

to engage saidvshoulders, an oscillatory tripplng cam plvotally mounted upon and movable Wlth sald reciprocatory element and ladapted for operative engagement with one of said detent-levers, means independent thereof for retracting the other ofv said detentlevers, and Vmeans connected with said tripping cam for actuating the same to retract the firstnamed detent-lever and to thereafter' act through said reciprocatory element to shift said plunger from one to position. relative to the 9. The combination with alrotary driven shaft, of a stopping-cam mounted thereon and` movable therewith, a brake device applied' to said shaft, a yielding motion-ar resting member adapted to engage said stopping-,cam for arresting the motion Aof said shaft, and means-connected with and convtrolled by said motion-arresting member for operating said brake device to apply a to 'its stoppage and-to relieve said frictional .drag subsequent to vthe engagement of said motion-arresting device With the stoppingcam and prior to the iinallstoppage of the shafts 10. The combination Witha rotary driven shaft, of a rotary member mounted upon and movable with said shaft and formed with a cam surface inclined to its direction fof rotation and an adjacent shoulder and with a second shoulder disposed ina different plane fromthe first-named shoulder, a swinging stop-lever movable transversely of the direction of movement of said cam, a spring-pressed plunger, mountedl insaid stop-lever and adapted to engage the cam surface and the adjacent shoulder of said rotary member, a second spring-pressed plunger mounted upon said stop-lever transverse to the first-named plunger and adapt-` ed to engage thesecond-named shoulder of said rotary member, means for shifting said stop-lever to throw said plungers into and out of operatlve relation with` said rotar'y .frictionaldrag upon -said shaft preparatory L member, and a brake device applied to said shaft and having an operative connection with the first-named plun er ivhereby it is caused to produce a frictional drag upon said shaft While the plunger is'in'operative relation Withsaid cam surface, they parts being so arranged and operated that theI second-named plunger engages its respective shoulder of said rotary member While the first is still in operative engagement with said cam surface.

4 11. The combination with ya rotary driven shaft, of a rotary member mounted upon and movable 'with said shaft and formed with an eccentric peripheral cam surface and an adjacent shoulder and with a second shoulder disposed in a different plane from the first-named shoulder, a brake-Wheel movement of. said cam, a longitudinal spring-pressed plunger mounted in said atop-lever and adapted to engage the cam surface and the adjacent shoulder of said rotary member, a second spring-pressed plun'ger mounted upon saidstop-lever transverseto the first-named plunger and adapted to'engage the second-named shoulder of In testimony whereof, I have signed my name to this specification, in the presence of two subscribing Witnesses.

ALFRED R. NVOOD.

Witnesses y JOHN J SHAW, HARRIS lV. RAND.

a5 fixed upon said shaft, a swinging stop-lever 1 movable transversely of the direction of4

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