US1173162A - Stop-motion. - Google Patents

Description

E. C. BASSETT.

y sToPvMoTioN. l "APPLICATION mw ulJLY 8,- nils. 1,173,162. l l l Patented Feb.29',1916.

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BWIER C. ASSETT, OF MILTON, MASSACHUSETTS, ASSIGNOR- T O REECE '.BIITION HIILE-MACHINE `COMPANY;A OF BOSTON, MASSACHUSETTS, A CORPORATION 0T FLAINE.

STOP-MOTION.

Specification of Letters Patent.

Patented Feb. 29, 1916.

Application inea :muy a, 1915.' serial 110.38373.

aleription," .in connection with the accompanying-drawing, is a specification, like characters oli-the drawing representing like parts-1 v y T'hisinvention relates to stop motions for scoring:machines and the like, and the objects ,of .the invention arel to provide a simple stoplmotion which is constructed to bring rthe machine to restwithl an easy cushioning movement and without any j ar or shock, and also to provide a novel stop motion in which when the machine is to be stopped the belt is shifted from the fast to the loose I'p'ulley in advance ofthe action of the stop device thereby giving suilicient time for the belt to be' fully shifted from the fast to the flbose pulleybefore the machine' is to be 'broughttojrest This is especially advantageous in high speed machines because it insures that the machine-will not be brought to rest until after the driving belt has been fully shifted onto the loose pulley.

In order to give an understanding of my invention I have illustrated in the drawings a selected embodiment which will now be described, after 4'which the novel features will-be pointed out in the appended claims.

Figure 1 of the drawings is a Side View of a portion of a machine having one form of my improved stop motion applied thereto; Fig. 2 is an underside view of the machine i showing one. means for automatically throwing the-stop motion into operation; Fig. 3 is atop plan view of the, stop mechanism; Fig. -l is a -yertical'sectional view thereof; Figs. 5, 6, 7, 8, 9, and l0 are side and plan views respectively of thestop cam in different positions; Fig. -11 is a section on the line .Q2-m, Fig. 1. Fig. 12 is a. detail of the.

cam for releasing the locking member.

I wish to state at the outset that my invention is applicable not only to sewing machines, but to other similar machines and is especiallyapplicable for use in connection with high speed machines.

1 designates the frame of the machine hiclris'provided with a driving shaft 2 by bhusetts, have invented an improvement' in topMotions, of. which the following. de"

which it is operated. This shaft is shown as having a pulley 3 fast thereon and a pulley 4 loose thereon.

5 is a driving belt which isfadapted to.

be shifted from the loose to the fast pulley for driving the machineand back to the loose pulley again when the machineis to be stopped. The belt is operated by a belt.

shifter 6 which'is herein shown as carried by 'a rock' shaft 7 mountedin bearings 8 carried by the frame 1. This rock-shaft can be turned to .throw the belt from the fast tothe loose pulley or vice versa' by any suit-A able means.

I have herein shown for'this purpose a handle 9= fast on the ,rock-shaft and have also shown said rock-shaft as pron vided w'ith an arm 10 to which a treadle maybe suitably connected, thus making it possible to shift 4the belteither by hand or by a treadle.` In some'machines the belt shifter is held in position to retain the belt Ion the fast pulley by continued pressure on the treadle, and lin some other machines a locking device or catch, is employed which holds the belt on the fastl pulley until said locking device is releasedwhen the machine is to be stopped. In the embodiment of the invention herein illustrated I have shown a construction of the latter type, and 11 designates a locking pawl pivoted on a stud 12 carried by the frame ofthe machine and acted' upon by a suitable spring 13, said spring operating to throw the dog into locking engagement with the arm 10 when the latter is depressed, thereby locking the vbelt shifter in the position to maintain the belt on the fast pulley. When theloclring pawl l1 is released the belt shifter will be thrown into position to carry the belt onto the loose pulley'by means of a. spring 14 which is herein shown as acting on an arm or plate l5 fixed to the rock-shaft 7, said spring being confined between said plate any suitable way.

E 1,173,162 l i ing pressure to the cam as Lne shaft rotates.

The stop cam is shown at 16 and it may be rigidly secured to the driving shaft 2 in present the eccentric portion 17 which merges into the straight-faced portion 1S.

Said cani is also formed with the inclined face 1S), the inner edge 20 of whicltfis con-V centricA with the shaft.

Thestop dog which coperates with the stop cani in stopping the machine is shown t at 21. Said stop dog is provided with the flat face 22 thatengages the stop cam and 1s carried by a shank `23- that 1s slid-ably mounted in bearings 24 formed in a frame or carrier 25 which is herein shown as sustained on the rock-shaft 7. This stop `digg is acted upon bya spring 2G which is herein shown as encircling the shank 23 and as bearing at one end against oneof the bear-i ings l2 1, and at the other end against a collar 219adjustably mounted on the shaft 23.

3QV is a stop collar fast on the shaft 23 and adapted to engage one of ,the bearings 21 for limiting the expansive movementof the spring 26. This collar is provided with the forked portion 31 which straddles the frame 25 and prevents turning-movement o f the shank.

' .A connection lbetween the frame or carrler and the rocleshaft isprovided by which when the rock-shaft is turned to shift the beltonto the fast pulley 3, the frame is moved into position to carry the stop dog to one side of the stop cam 16, While when the belt shifter is shifted to carry the 'beltonto the loose pulley, the frame 25 will bemoved to 'carry the stop dog into position to engage the stop cam 16. When the belt shifter is moved to carry the belt onto the loose pulley the stop dog will move over the inclined face 19 of the stop cam so as to bring the square end 22 thereof against the face of the stop cani. As the shaft rotates the eccentric portion 17 of the stop cam acts en the stop dog 21 and forces it rearwardly against the spring 26 whereby an increasing frictional braking pressure is applied to the stop cam. As the shaft continues to rotate the. braking pressure .increases with the increasing eccentricity of the portion 17 until the cam is turned sullicicntlv to bringthe fiat face 18 against the flat face 22 of the dog, as shown in Fig. 1. If the machine has not been completely brought to rest at this time, the further continued movement of the cam will cause the flat face 18 thereof to act on the point 27 of the dog, as shown in dotted lines Fig. 9, thus bringing the machine to rest with a .cushioning or yielding action.

It will be noted that the point 27 of the stop dog against -which the flat face 18V operates when the4 stop cam is in the-dotted line position shovvn in Fig 9 isfsituated out Said cam is formed to engagement with the rstop cam 1S.L

of the axial line of the shank and considerably above thefaxial line of the shaft2. As a result a slight angular turning mover ment of the stop cam will placethe spring 26 under a very greatly increased tension and, therefore, the shaft 2 will be quickly brought to rest afterlit` has passed the position shown in Fig. l. This final movement of the shaft in coming to rest will, however,

be a cushioned movement which will be freeV from shock or jar.4 Itwvill -be understood,

of course, that after4 the forward rotation ,of the shaft is stopped, 'the'action of the springi26 will turn the shaft 2 baekivardly slightly until the flat-face 22 oftliestop dog rests 'flatly-against the'flat face 18of1the stop cam,zas shown in Fig. '1.v. y The eccentric 't portion 17 ofthe stopfcam'coperates with' `the stop dog 21 to` provide-a `brake device for gradually bringing the shaft to rest, 'and the 4Hat face 18of` thestop Lcam coperaties with the .flat face- 22'of the.v stop dog and y The stop dog 21- is` so sustained -that the axial line of the shank 23 thereof `intersects the corner 27. thereof :to bring-the shaft to rest quickly but with acushioned movement. p

" the diameter'fof the shaft25and thestraight 'i i face 18 of the stop learn is so 'shapedthat pendicnlarto thefaceflS would intersect theA latter' 1s4 a less distance from? the 'center 'of the'shaft'than the point29 vvhere the eccen- `the point 28 thereofwhere afra'dial line pertric portion 17 merges inte thestraight p'oif` tion. As a result, When-the stop dog A21 leaves the eccentric portion 17 and comes onto the straight "portion 18, the frictional pressure will bereleased slightly until'the parts come into theposition shown in Fig. 1, after which the frictional'braking pressure will be increased,v as above described.`

One feature of my invention relates to a ico construction whereby when the' machine is i 4viding a construction which prevents the frame 25 from moving 'until after the ,belt

vshifter .has'been given its movement.

The carrier 25 is shown as loosely mounted on the rockshaft 7, and the arm or plate 15 is provided with an extension 32 that over'- lies the frame so thatwhen the rock-shaft the fast pulley, the engagement' of the ex-V tensio n 32 with the frame will 'move it into a position to carry the stop dog 2 1 out" of ,is turned to shift the belt from the loose to' rsa imanes frame 25 is acted upon by a suitable spring 33 which tends to move it laterally into a position to carry the stop dogQl into the plane of movement of thev cam 16. Vlhen the rock-shaft 7 is turned to shift the belt to the loose pulley the frame 25 will be pxiigventedfrom swinging outwardly under t e action of the springI by the engagement of the stop dog with some portion.. of the stop cam outside of the eccentric face, which portion is referred to generally by the nu-YY meral 34.y This is the position shown in Figs. 5 and .6, As the stop cam turns and the inclined face 19 comes opposite the stop dog, as shown in' Figs. 7 and` 8, then said stop. dog will move down the inclined; face under the action of the springv 33, thus bringing saidddog into position to engage. the eccentric portion 17 of the stop cam 16. There is, however, a sufficient interval of time between the shifting of the belt shifter and the movement'of the frame 25 to permit the belt to be completely shifted onto the loosel pulley before the stop dog comes into engagement with the eccentric face 17 of the stop cani and begins to apply a frictional braking pressure thereon. v

lWhere a locking pawl such as 11 is used 'forholding the belt shifter on the fast pulley, the operation of ystopping the machine involves releasing this locking pawl. ln the illustrated embodiment lof my invention l have shown means for automatically releasing this pawl at the end of a predetermined cycle' of movements. Such means comprises ai cam35 on a rotary part 36 of the machine, which cam is adapted to engage fanarm 37 extending from the locking pawl ll when the part 36 reaches a predetermined point in its rotation, thus releasing the latch. The parts are so timed that this release of the latch il will take place when the stop cam is in such, a position that the portion Si thereof is opposite the stop dog 21 with the result that-when the latch is released the stop dog will come against the portion 34 of the cam and thus be prevented from moving over into its operative position until the cam has rotatedsuiiiciently to bring the inclined face 19 opposite the stop dog. The belt shifter will, however, be shifted to carryl the belt onto the loose pulley as soon as the llocking dog l1 is released and, therefore, there will be an interval of time elapsing between the shifting offthe belt onto the loose pulley and the action of the stop dog on the eccentric portion of the stop cam which is sufficient to insure Ithat the belt will be entirely shifted onto the loose pulley before the stop dog begins to apply its braking pressure. i-

My invention is applicable to machines of various types and while l have illust'iiated herein a selected embodiment of myinvention l do not wish to be limited to the constructional features shown. t

bring the shaft to rest, a support for saidstop member, said stop cam having associ- Y,

ated therewith means controlling the movement of said support whereby the stop member is prevented from coming into operative engagement with the stop cam until after the belt shifter has been shifted into position to bring the belt onto the loose pulley.

2. In a stop motion, the combination with a driving shaft, of a driving element therefor, means to establish an operative or non operative connection between said driving element and driving shaft, a stop cam fast on the driving shaft, said stop cam being provided with an leccentric surface which merges into` a straight surface,'a stop member, means supporting said stop member for movement in a directionat right angles to i vtheaxis of said shaft, said stop member having a substantially fiat face extending in a plane at right angles to' its direction of vmovement, a spring acting on the stop member, and means to move said stop member into engagement with the eccentric face of the stopk cam whenthe driving element is disconnected from the driving shaft, the flat face of the stop member coperating with ythe at face of the stop cam to bringthe drivingA shaft to rest with a cushioned movement. y

3. ln' a stop motion, the combination with a driving shaft having a fast and .a loose pulley thereon, of a rock-shaft, a belt shifter fast on the rock-shaft, a stop fast on the driving shaft, a frameloosely pivoted on the rock-shaft, anda spring-pressed stop member carried by said frame, said stop cam having associated therewith means to hold the stop member from operative engagement therewith for a time interval after the belt shifter vis operated to throw the belt onto the looseV pulley. f 4. In a stop motion, the combination with a driving shaft, of a fast and a loose pulley thereon, a belt shifter for transferring the driving belt from one pulley to the other, means to actuate the belt shifter, astop cam fast on the shaft and having an eccentric,

holding the stop member out of operative f 130 position while the driving shaft makes a a driving shaft haring a fast and loose pnlley thereon, of a rock shalt, a belt shifter rigid with the roc-lt shaft lor shifting a belt frein one pulley 'to the other, a stop cam f .fast on the driving shaft, a frame mounted on. the .rock shaftand capable Aof a limited turning movement relative thereto, a springpressed stop member carried by said trame and movable therein in .1 direction at right angles to said shaft, movement of the'frame on the rock-shaft operating to carriv said step member into and ont of engagement with said stop cam, said stop cam having means aeelieiated therewith to prevent the trame from, turning on the roel; Shaft into e position to carry the stop member into op- 'slidabbY mounted in sai( erative engagement with the stop cam for a time interval after the belt has been shifted by the belt shifter.

(l. In a stop motion, the combination with a drivingr shaft, of a tast and a loose pulley thereon, a lock shaft, a belt ebifter rigid therewith for transferring the bult from one pulleyr t the other, a trame :Bfimounted on the rock shaft for turning movement relative thereto, a stop dofr 2l having a stem lzframe, and a spring acting on said stem, said stop czam having provision for preventing the stop member from engagg'img, the periphery thereof for a predetermined time interval after the belt has been shifted onto the loose pelley.

In testimony whereof, l have signed my name to this speeilieation.

ELMER C. BA SSETT.

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