US1878091A - Stop-motion device - Google Patents

Description

Sept. 20, 1932. ALLEN ET 1,878,091

STOP MOTION DEVICE Original- Filed April 24. 1928 5 Sheets-Sheet l 66m; M a ATTORNEY Sept. 20, 1932. E. B. ALLEN ET AL STOP MOTION DEVICE Original Filed April 24, 192? 5 Sheets-Sheet 2 INVENTOR figura flA/len/ 7/6110) {Myers A TORNEY Original Filed April 24, 1928 5 Sheets-Sheet 3 I!lIlllllllllllllllllllllllllln...

N V E N TO R Ell/aid BAl/en/ i Walter Z@ers ATTQRN EY WITNESS Q Sept. 20, 1932. E. B. ALLEN ET Al.

, STOP MOTION DEVICE 5 Sheets-Sheet 4 INVENTOR Zia/and flAl/en/ ATTORNEY Original Filed April 24. 1928 Sept. 20, 1932.

E. B. ALLEN ET AL STOP MOTION DEVICE 5 SheetS-Sheet 5 Original Filed April 24, 1928 Eli. 1| ll ITNESS Patented Sept. 20, 1932 UNITED STATES PATENT 0mm I EDWARD B. ALLEN, OF NEWTOWN, AND WALTER.MYERS, 0F BRIDGEPORT, CONNECTI- CUT, ASSIGNORS TO THE SINGER. MANUFACTURING COMPANY, OF ELIZABETH, vNEW j JERSEY, A GORPGRATI ON OF NEW ERSEY STOP-BIOTION DEVICE Application filed April 24, 1928, Serial No. 272,416. Renewed September 11, 1931.

This invention relates to devices for stopping machines, such as sewing machines, at a'predetermined'time and with the parts in a predetermined position.

One form of stop-motion device commonly used is shown in the patent to Allen, No.

743,213, of Nov. 3, 1903. 'It comprises a termined position. The shock of stopping the moving parts of the machine is borne by the butter-spring means between the stopcam and the machine shaft. This shock is in the nature of a sharp hammer blow and is such that quite a strong buffer-spring is re,- quired to absorb it. Known stop-motions of this character area speed-limiting factor of machines to which they are applied. In fact a machine with such a stop-motion must be operated at a moderate speed or considerable difliculty is experienced with buffer-spring breakage and distortion or undue-wear on the parts. r

The present invention has for an object to provide a stop-motion device, which .will permit of higher machine speeds withincreased production, and in which the shock of stopping the machine is materially reduced and bufi'er-spring breakage is overcome. Another object of the inventionis to adapt the stop-motion device for use moreparticularly with buttonhole sewing machines in which the power for operating the buttonhole cutter is derived from the momentum of the machine acting preferably through the stop-motion device after the machine is disconnected from its driving means;

a further object being to secure increased ower for operating thev buttonhole cutter.

Still further, the invention has for an object to provide a stop-motion device in which usual stop-cam of the stop-motion devi'ce, 'in+ stead of being mounted upon the driven shaft of the machine, is associated preferably with "an idly running gear meshing with afsmaller pinion fixed to the driven shaft, whereby the stop-cam is caused to run, say, at one-half the speed of the driven shaft. When applied to a buttonhole sewing machine, this gear and stop-cam may conveniently be mounted on a stud carried by the machine frame at one side of the main-shaft; the usual stop-motion lever being moved laterallyfrom its old position below the main-shaft, to its new position below the gear. Since the stop-cam runs at half its former speed, it follows that the machine hastwice the time to run under its own momentum from the time thejpower is thrown ofl? until the positive stop comes into play, This increased coasting time results in an absorption of energy by friction inthe machine bearings and a lessening of the energy to be absorbed by the stop-motion de- 1 vice. Furthermore, the character of the blow I imparted to the buifer-spring means is changed. Instead of being in the nature of a sudden or sharp hammer below, it is more like a push and can be better absorbed'by the buflier-sp'ring with less strain upon thelatter.

Still further, when applied to a buttonhole sewing machine of the type where the *but tonhole cutter is operated by the down-motionof the stop-plunger under the influence of the eccentric portionqof the usual stopcam, the two-to-one reduction gearing gives increased power for cutting the buttonhole, as may be desirable with heavymaterials or when cross-seams are encountered.

In the accompanying drawings, Fig. 1 is a side elevation of a buttonhole sewing machine embodying theinvention. Fig. 2 is a bottom plan view of the machine. 3

Fig. 100

is a rear end elevation of the machine.

4 is a disassembled perspective view of the idly running gear and associated parts, including the stop-cam. Fig. 5 is a top plan view of the upper parts of the machine carried by the bracket-arm. Fig. 6 is a section, on an enlarged scale, on the line 6-6, Fig. 1. Fig. 7 is a section on the line 7-7, 5. Fig. 8 is a section on the line 8-8, Fig. 5. Fig. 9 is a transverse vertical section through the machine bed and bracket-arm, showing the driving connections for the feed-wheel shuttle mechanism 8 to form the buttonhole stitches. The cutter-bar 6 has fixed to its lower end theusual buttonhole cutting knife 6 which, at the end of the sewing operation, is projected downwardly to cut the buttonhole slit.

The needle and shuttle mechanisms are driven in the usual manner from the mainshaft 9 which is ournaled within and lengthwise of the bracket-arm 3 and carries at its rearward end the tight and loose belt-pulleys 10 and 11. The pulley 10 has an elongated hub 12 in which gear-teeth are cut forming a pinion 13; the hub 12 being fixed to the mainshaft 9 by means of the taper-pins 14 disposed on opposite sides of the pinion 13 and bearing a 90 angular relation to one another, as shown in Fig. 6. The loose pulley 11 is journaled on the bushing 15, Fig. 7, which is confined to rotate with the shaft 9 by means of the pin 16 which enters a notch 17 in the bushing.

The sewing machine frame is formed at the bend of the bracket-arm, adjacent the upper end of the standard 2, with a boss 18 which is laterally offset from the rear main-shaft bearing 19 and has fixed thereto the stud-pin 20 on which is journaled the gear-wheel 21 meshing with the pinion 13. As will be noted 'in Figs. 3 and 5, the stud-pin 20 is parallel to the main-shaft 9 and is disposed substantially at the level of such main-shaft; being merely displaced to one side of the latter. The gear-wheel 21 has a forwardly eXtending hub 22 on which is journaled the usual stop-cam 23 having the eccentric stop-plunger-depressing portion 24 followed by the stop and rebound-preventing notch 25. Thestopcam 23 has fixed thereto a pin 26 which eX- tends through a slot 27 in the face of the gear 21 and has fitted thereon a block 28. The block 28 is disposed within the cavity 29, Fig. 4, of the gear 21 and there is also fixed withwardly into the stop-notch 25.

The stop-motionlever 38 is heldinits run- Mounted on the standard 2, at the base of the latter, is the bracket 35 having spaced arms 36 for the trunnion-screws 37 which support the tilting stop-motion lever 38 formed at its upper end with a lateral arm 39 carrying the belt-shipper fork 40. Mounted to slide verticallyin the stopanotion lever 38 is the usual stop-plunger 41' which is pressed upwardly by the spring 42. When the stop-motion lever 38 is in running or dotted line position, Fig. 1, the upper end of the plunger 41 is disposed forwardly of the cam 23 and is out of range of the latter.

When the stop-motion lever 38 assumes its stopping or full line position, Fig, 1, the plunger 41 is moved to a position under or within range of the cam 23, whereupon the eccentric portion 24 of such cam first depresses the stop-motion plunger 41 against the force of the spring 42 and then releases the plunger as the latter rides off of the end of the eccentric portion 24 and is projected upning or dotted line position, Fig. 1, by means of a latch-lever43 -which enters the notch 44 in the side of the rod 45 connected 'by the screw 46 to the arm 47 rigid with thestopmotion lever 38. The latch 43 carries the adjustable tripping-point 48 which is acted upon-at the end of the sewing'cycle by the tripping-point 49 carried by the feed-wheel 50; the feed-wheel being connected in the usual manner to move the work-clamp 50' on the bed 1 to feed the work. 1

Fixed to the stop-motion plunger 41 by means of the screw 51 is the horizontal bar 52 carrying at its outer end the roller 53 enterlever 55 which is fulcrumed at 56 on the standard 2. The lever 55 is connected in the usual manner to the cutter-bar 6 by means of the link 57,-lever 58 and link 59. The link 57 has pivoted thereto at 60 the lower end i of the latch 61 having at its upper end a shoulder 62 which engages under the pin 63' carried by the lever 58 and passes through the slotted -upper end of the link 57. This is the usual No. 743,213, for preventing the operation of the cutter-bar by the stop-motion device; the release being efiected by manually swinging the slot 54 in the rearward end of the l manual release, disclosed in said Allen patent ing the link 61 to carry its shoulder 62 out from under the pin 63.

The feed-wheel 50 is mounted on the shaft 64 to the upper end of which is fixeda gear 65 meshing with the pinion 66 fast to the gear 67 meshing with the pinion 68 secured to the lower end of the shaft 69. The shaft 69 has fixed thereto the usual star-wheel 7 0 which is given a step-by-step motion by the pins 71 carried by the bevel gear 72 which meshes with the driving pinion 73 fixed to the mainshaft 9.

It will be noted from the foregoing description that the power for driving the machine is not transmitted through the gearing 13, 1,

' but is transmitted directly from the pulley 10 to the main-shaft 9; the gear 21 which carries the stop-cam 23 running idly without noise or wear and tear while the machine is in operation.

The tripping-point 48 should be adjusted to release the stop-motion lever38 at a time when the concentric or low portion of the stop-cam 28 is adjacent the upper end of the plunger bar 41. On the cam 23 there is an angular space of about 90 where the tripping may take place and permit the plungerbar 41 to pass under the cam for engagement by the eccentric cam-portion 24. As the cam 23 is geared to run at half the speed of the main-shaft 9, it follows that the main-shaft may turn through a space of 180 or twice as far as would be permissible were the cam 23 mounted on the main-shaft. Hence it is not necessary to adjust the setting of the tripping point 48 to the degree of accuracy heretofore required.

It is found that with the present stopmotion device lighter buffer-springs may be used with increased machine speed and, due to the more gradual character of the blow absorbed by such buffer-springs, breakage of the latter is eliminated.-

Having thus set forth the nature of the invention, what we claim herein is 1. In a stop-motion device, the combina tion with the driven machine shaft, driving means, and means for establishing and interrupting driving relation between the driving means and driven shaft, of a stop-cam geared to said driven shaft to run idly at a reduced speed while the machine is in operation, said stop-cam having an eccentric portion followed by a stop-notch, a stopmotion lever, and a spring-pressed plunger carried by said lever and movable into and out of cooperative relation with said stopcam, and buttonhole cutting mechanism connected tobe operated by the movement of said plunger under the influence of the cocentric portion of said stop-cam.

2. In a buttonhole sewing machine having a main-shaft, the combination with a stopmotion device including means geared to the main-shaft to run at a reduced speed and a stop-cam driven by said means, ofbutto-nhole cutting mechanism connected to be operated by said means' 3. In a buttonhole sewing machine having a main-shaft, the combination with a stopmotion device including a stop-cam geared to said main-shaft to run at a reduced speed, of buttonhole cutting mechanism connected to be operated by said stop-cam.

4. In a buttonhole sewing machine, a main shaft, stitch-forming mechanism, rotary means driven by the main-shaft at a reduced speed during a stitching operation, a stop motion device including means for disconnecting the main-shaft from its source of power, and buttonhole cutting mechanism connected to be operated by said rotary means under momentum after the main-shaft has been disconnected from its source of power.

5. In a buttonhole sewing machine, a mainshaft, power-means, means for establishing and interrupting driving relation between the main-shaft and said power-means, stitchforming mechanism, and buttonhole cutting mechanism including a rotarybuttonholecutter-actuator connected to said main-shaft to run at a reduced speed and timed to actuate the buttonhole-cutter while the machine is running under momentum.

6. A buttonhole sewing machine having, a main-shaft, stitch-forming mechanism, a work-clamp, means for relatively moving the stitch-forming mechanism and work-clamp during a sewing period, power-means, a. stopmotion device for disconnecting the mainshaft from the power-means at the end of a sewing period, a buttonhole cutting mechanism and a power-multiplying gear-connection between said main-shaft and said buttonhole cutting mechanism for actuating the latter-under the momentum of the machine after the main-shaft has been disconnected from said power-means.

In testimony whereof, we have signed our names to this specification.

EDWARD B. ALLEN. WALTER MYERS.

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