US2138403A - Driving and stopping mechanism - Google Patents

Description

DRIVING AND STOPPING MECHANISM Filed Oct. 25, 1934 5 Sheets-Sheet l NOV. 29, 1938. J GOULDBOURN ET AL 2,138,403

DRIVING AND STOPPING MECHANISM 5 Sheets-Sheet 2 Filed Oct. 25, 1934 1938- J. GOULDBOURN ET AL 2,138,403

DRIVING AND STOPPING MECHANISM 5 Shets-Sheet 3 Filed Oct. 23, 1934 1938- J. GOLILDBOURN ET AL 2,138,403

DRIVING AND STOPPING MECHANISM 5 Shets-Sheet 4v Filed Oct. 25, 1954 1933- J. GOULDBOURN ET AL 2,138,403

DRIVING AND STOPPING MECHANISM Filed Oct. 23, 1934 5 Sheets-Sheet 5 Patented Nov. 29, 1938 UNITED STATES PATENT orrics DRIVING AND STOPPING MECHANISM Application October 23, 1934, Serial No. 749,594 In Great Britain November 28, 1933 26 Glaims.

This invention is concerned with improvements in or relating. to driving and stopping mechanisms and is hereinafter illustratively described as concerned with machines which are arranged to sew together parts (such for example as the end, side and bottom portions) of a suit case,

attache case or the like which extend at right angles to each other.

When a high speed machine is used for sewing together. the parts of a case or the like, pronounced difliculties would become manifest if it were attempted to stop the machine suddenly by the use of a single revolution clutch of customary type since great strains would be thrown suddenly on to numerous parts of the machine and excessive wear and possible breakage would be thereby entailed.

An object of the present invention is to provide, for use in a high speed machine, a particularly efficient and novel form of stop motion for bringing the machine to rest from its high speed within a very short time without throwing excessive strain on parts of the machine.

As will be appreciated greater care is necessary on the operators part in controlling the work during the putting in of individual stitches around an end corner of a case than is necessary during the sewing of a seam along a straight edge of the work, and greater care is also necessary in controlling the work when workpieces of small or awkward shapes (such for example as parts of saddle-bags for cycles or parts of cases for musical instruments) are being sewn to gether than when relatively large pieces of simple shape are being sewn together.

Accordingly, another object of the present invention is to provide, in a high-speed machine, a novel form of variable-speed driving mechanism by which the machine may be driven at a high 40 speed when the nature of the work being opereted on will allow of it and by which it may be driven at a reduced speed when the nature of the work calls for greater care on the part of the operator.

The machine hereinafter described is provided with a two-speed driving mechanism, controlled by the operator, by which the machine may be caused to run at a relatively high speed when desired and by which it may be caused to run at a considerably lower speed when desired. A stop motion is provided, which may be controlled by the operator to allow the machine to sew a seam of stitches in a continuous manner before the machine is brought to rest and may also be controlled to cause the machine to come to rest after sewing but a single stitch when the operator so desires, which stop motion, when rendered operative, applies a braking effort to the machine to bring it to rest and a dashpot is provided for automatically causing the braking effort to operate over a longer period when bringing the machine to rest from high speed than when bringing the machine to rest from low speed. Such arrangement allows progressively decreasing braking effort to be applied to the moving parts of machine so that they are brought to rest with great smoothness thus avoiding straining the parts and obviating shock on the stopping of the machine.

The various objects and the several features of the present invention (which latter are set out in the appended claims) will be fully understood from a consideration of the following description with reference to the accompanying drawings.

In the drawings:--

Figure 1 is a left hand side elevation of the machine of the illustrative embodiment.

Figure 2 is a left hand side elevation, partly in section and to a larger scale of the lower portion of the head.

Figure '3 is a front elevation, also partly in section and to the same scale as Figure 2, of the left portion of the machine head.

Figure 4 is an isometric View, on an enlarged scale (from the right hand side) illustrating how certain trip levers cooperate with certain latches of the machine.

Figure 5 is a view similar to Figure 4 but looking from the opposite side.

Figure 6 is an isometric View, from below and from the right, showing details of a pawl associated with the two-speed driving mechanism, and

Figure 7 is a left hand side elevation, partly in section, showing certain parts of a two-speed driving mechanism for the machine.

The machine of the said illustrative embodiment comprises a column I on the upper end of which a head casting 3 which supports the sewing and other instrumentalities together with their actuating mechanisms, is mounted. Near the lower end of the column and on its left hand side is mounted a countershaft 5 which extendforwardly and rearwardly of the machine and has fast and loose pulleys I and 9 on its rear end. The countershaft also has mounted on it, near its forward end, a two-speed driving device hereinafter described which is coupled by a belt 6 l to a driving pulley i3 situated on the left hand and of a horizontal main shaft l5 of the machine iii which extends transversely of the machine (i. e. from left to right) in the machine head. A single treadle H is provided for causing a driven member I9 secured to the machine shaft I5 to engage with the said driving pulley to set the machine in operation and for causing the two speed driving device to drive the pulley I3 at a high speed or a low speed at will.

The machineof the present illustrative embodiment is provided with an external work support 49 (which is similar in general appearance to that referred to as 28 in Patent No. 1,695,? 18) which work support has two relatively long work-supporting faces extending parallel to the line of feed and arranged at right angles to each other to support two work-pieces (e. g.

the bottom or a side and an end portion of a case) which are to be sewn together at right angles.

In order to maintain the two parts of the work to be sewn together in proper position on the external work support 49, a work-entering horn indicated at 53 is provided in the illustrative machine which horn is generally similar in appearance to that referred to as I in Patent No. 1,695,718, but which carries, in place of the work-engaging tablet 43 described in that specification, a pair of small freely rotatable frusto conical rolls 55, 51 (the rear sides, 1. e. the workengaging sides) of which are mutually perpendicular and are maintained in parallel relation to the mutually perpendicular work-engaging faces of the external work support 49.

The two-speed driving device aforementioned on the countershaft 5 of the machine comprises a gear wheel I 89 fast on the forward end portion of the shaft with which gear wheel mesh two pinions I9I (one only of which is shown in Figure 7) mounted on pins I93 projecting forwardly from a pulley member I95 freely rotatable around the countershaft close to the rear side of the gear wheel, the said pins being arranged diametrically opposite each other on the pulley member. The two pinions I 9I also mesh on their outer sides with an internal gear I91 formed around the interior of the periphery of a drum I99 freely mounted on the forward end of the shaft which drum is arranged to be held stationary when the machine is to be driven at low speed by a relatively fixed pawl 20I (Figures 1 and 6) engaging ratchet teeth 203 formed on an annulus secured to the drum I 99 so that rotation of the countershaft will, through the rotation of the gear wheel I 89, cause the pinions I9l to run around the internal gear I91, and thus impart a rotation to the pulley member I95 which takes place in the same direction as the rotation of the countershaft. The relative dimensions of the gear wheel I89 pinions I9l and internal gear is? are conveniently such that when the pulley member is driven through theepicyclic train just described, it makes one revolution for every three revolutions of the countershaft.

The countershaft has rigidly secured to it just rearward of the pulley member a disc 205 to which is secured on that side nearer the pulley membera leather friction ring 297 and the pulley member I95 is arranged to be slid rearwardly p then inoperative.

along the shaft into firm clutching engagement with this disc whenit is desired to drive the machine at high speed, the epicyclic gearing being controlling treadle I! of the machine is coupled to a quick-pitch plunger 209 arranged coaxially with the countershaft the rear end of which For this purpose the clutch plunger bears against the end of a sleeve on the forward side of the drum I99. Depression of the said treadle to its lowest position causes a rearward movement of the said plunger which thereupon urges the drum I99 rearwardly along the countershaft to press against the pulley member and thus move it also rearwardly, so that the pulley member becomes firmly clamped between the drum I99 and the disc 295, the pulley then being driven uniformly with the countershaft at the same speed and in the same direction as the latter. When the pulley member becomes thus clamped against the said disc the epicyclic gearing before described rotates as a whole with the pulley member, countershaft and drum and therefore is inoperative to drive the pulley member at its reduced speed.

The pawl 29I. aforesaid which engages the ratchet teeth on the drum to hold the latter stationary while the pulley member is being driven at its low speed is secured on a horizontal and freely rotatable pin 2II (Figure 6) and has a short arm 2i9 secured to it which carries a plug of leather 2I5 which contacts with the forward face of the drum I9 9. The pin 2 is mounted in a fixed lug 2I'l and is urged rearwardly to press the leather plug 2I5 against the drum by a spring 2I9 encircling it and bearing against a shoulder on it.

The action of the epicyclic gearing, when the pulley member is being driven at its low speed, tends to cause the drum to rotate in a clockwise direction when-viewed from the front, 1. e. in a direction opposite to that in which the countershaft runs, and the friction between the leather plug and the forward face of the drum swings the pawl into engagement with the teeth on the drum to prevent the drum rotating in this direction. When however the pulley member and therefore also the drum is directly driven from the countershaft through the-disc 205 the drum rotates in a counterclockwise direction and the friction between the leather plug and the drum causes the pawl to swing to a position in which it is out of engagement with the teeth on the drum. A stop pin 22I secured to the arm 2I3 lies within a cut-away portion 223 of the lug 2H and by contact with the lower end thereof limits the swinging movement of the pawl away from the ratchet teeth.

The pulley member I is coupled by the belt II to the pulley I3 which is freely rotatable on the main shaft I5 of the machine by which latter pulley the machine is driven through a cooperating clutch member hereinafter described. Conveniently the two speed driving device is arranged to drive the machine at a high speed of 900 revolutions per minute and a low speed of 300 revolutions per minute. 7

For ensuring that the machine, whether it is being run at its high speed or its low speed, will be brought to rest smoothly and evenly in a single revolution vwlthout imparting severe shock to the machine parts and to ensure that the various operating instrumentalities will occupy the positions desired when the machine has come to rest, there is incorporated in the illustrative machine a stop motion of novel and ingenious character which will now be described.

The pulley I3 on the main shaft of the machine is freely rotatable on the left handend of the main shaft l5 and as shown in Figure 3 is dished inwardly from its right hand face to provide an internal clutching face 225. A cooperating clutch member 227, dished to correspond with the said internal clutching face :225, is'keyed to the shaft [5 ito"the :right of "the pulley and is arranged to be slid axially along the shaft'itowards the left into clutching engagement with the said pulley. The cooperating clutch"member 221 is also 'arranged ito be slid towards the right out of en- 'gagement with the pulley l3 and into engage- 'ment with a "stationary braking face "229 surrounding the main shaft to bring the machine parts to rest. The cooperating clutch member 22 7 "has fa sleeve-likel'hub "2'3l extending to the right along the main :shaft and a cam "groove iifis'ris formed around said hub. A short forwardly and rearwardly extending rod "235 passes below'th'esaid hub at right angles to the main shaft and has pivoted onit two'clutch trip levers 231, 239 which extend upwardly on the forward and :rear sides of the said =hub respectively and carry cam rolls 2 2i (see particularly Figures 4 and :5) which engage in-the opposite sides ofthe 'carn groove 233 in the hub. The lower "ends of these trip levers 'liermore or'less side by side, consideredffor-wardly and*rearwardly of the machine, and the formation of the cam groove'233 is such that the lower ends of the trip levers *move to and'fro, in opposite directions :to each other and at 'a'substantially constant velocity when the machine is running at a constant speed, once in each machine cycle. The rod 235 has eccentric end'portions which enter into fixed bearings so that by rotating the rod the positions of the lower ends of the trip levers towards the left or right of the machine can be adjusted. Four springs 243 housed within the hub of the 00- operating clutch member tend to urge the latter along the shaft towards the left into clutching engagement with the pulley and a pair of latches 2&1, one for-each of said trip levers, is provided to engage with the lower ends of the trip levers at certain times and, by holding these lower ends against movement towards the right, to cause-thecooperating clutch member to be moved out of engagement with the pulley and into engagement with the stationary braking -face, through the action of the'cam groove on the cam rolls at the upper end of the trip levers in a manner which will be clearly understood.

The latches 245, 24! comprise a pair of fingers pivoted side by side (considered forwardly and rearwardly of the machine) on a horizontal forwardly and rearwardly extending pin 249 which is carried by a depending arm 25! of a bell crank carrier lever which is mounted to rock about a fixed horizontal shaft 253 and has a laterally projecting arm 255 to which is'co-nnected means hereinafter described. The latches are normally urged upwardly by springs 25! (indicated only in Figure 3) secured to them until their left hand ends contact with the lower ends of the trip levers.

The rearward one 24'? of the two latches has an upwardly extending shoulder 259 formed on it against which the right hand side of the lower end of the rearward trip lever 239 is arranged to strike in the manner hereinafter described when the machine is to be brought to rest when running at low speed (the forward latch and the forward trip lever playing no part in braking the machine when it is being brought to rest from low speed) and by which, since movement of the lower end of this trip lever towards the right is thus prevented, continued rotation of the main shaft causes, through the cam groove 233, the cooperating clutch member to be disengaged from the pulley and brought into firm contact with the stationary braking f'alc'e 2'29 tofstop tlfe- 'machine. The forward one 2B5 6f 'thef-two latches also has an upwardly extending shouldr 2 3! formed on it"which shoulder is speeeo rurther towards 'the right 'of the machine than the shoulder 259 on *the rearward latch for a purpose hereinafter described and cooperates with the 'forward'on'e 2 3'! of the trip levels to assist the rearward'latch and tlierearward trip lever' to bring thema'oh-ine smoothly to rest in a single cycle when running at high speed in the "manner hereinafter explained. To enable the machine to be started into operation at low speed the rearward latch 24-! is ar'r'anged 't'o be drawn'downwardly out of engagement with the trip lever 239 and th enable the machine to be started into operation at high speed both latches are arranged to be "drawn downwardly away rrem the lower ends of the trip levers to 'allow the cooperating clutch 'member to be moved by *the springs 253 to engage the pulley 'oh th'ehiaih shaft by connections to the clutch treadle 11' the precise arrangement of the means "for withdrawing the latches being hereinafter "described.

It will be appreciated that if the latches were held in fixed position after the trip lever 23! has engaged the shoulder 26! on the forward latch 2 35 when the treadle has "been released to bring the machine to rest from high speed the cooperating clutch in-ember aforesaid "would be likely to be thrust and held against the stationary braking face "with great "force and'therefore great strain would be likely to be imposed on the machine parts since the action of the cam groove 233 would be to endeavour to bring the cooperating clutch member to rest almost immediately it engaged the braking face, If on the other hand the latches were able to move towards the right against but a light resistance under the action 'of the trip lever 237 as the latter 'ehgag'es't'he shoulder 25! on the latch 255 in stopping from high speed it would quite likely be found that theresistan'ce offered by the latch to movement *of the trip lever 23! "would be insufiicientto bring the machine to rest smoothly in the manner desiredJ In "order to overcome these. difficulties there'is provided in the present illustrative embodiment an adjustable dashpot device which is so coupled to the latches as to offer such a firm yet yielding resistance to movement of the latches towards the right as the machine comes to rest from high speed that, immediately the trip lever 28! engages the latch 245, the cooperating clutch member will be moved out of clutching engagement with the pulley and into firm .yet not excessive engagement with the stationary braking face, the said dashpot also acting to control the braking pressure between the cooperating clutch member and the stationary braking face in such a manner as to'bring the parts of the machine smoothly to rest within the final cycle.

The said dashpot device comprises a main oil chamber 263 of substantially cylindrical shape which is enclosed on all 'sidesan'd has a vertical valve 255 passing axially through it which seats on a valve seating 261 in the bottom 'of the oil chamber. An oil duct 259 runs from the bottom of the chamber 2&3 below the valve to the bottom of a vertical open topped cylinder Eli secured to the side of the oil chamber. A dumbbell'plunger 273 is 'slid in'gly mounted in this cylinder and makes a fairly tight fit in the cylinder. A rounded lower end of a rod 21? rests within a d'epressidn in the upper end of the plunger 213 55, sage 289 is bored upwardly in the valve 265 and this rod is connected'at its upper end to the arm 255 of the bell crank lever to which the latches are pivoted.

This arrangement is such that when either of the trip levers 231, 239 engages the shoulder on one of the latches 245, 241 and therefore acts to move the latches toward the right, the pushing action of the trip lever on the latch will swing the arm 255' downwardly and thus cause the plunger 213 to be urged downwardly along the cylinder 21L Downward movement of the plunger is resisted by the presence of the oil beneath it which however is allowed to escape from below the lower head on the plunger (which alone of the. two heads on the plunger is actually submerged in the oil) upwardly through the latter by means of an adjustable port 219, constituting a bleed valve, the eifective opening of which can be varied by adjustment of a conicalended stem 29! threaded into the plunger and projecting at its lower end into the port 219. As will be understood therefore the plunger 213 and the cylinder 21! constitute a dashpot device which offers a firm but yielding resistance (which is variable by adjustment of the stem 29!) to movement of the latches towards the right during the final cycle of the machine and therefore causes the cooperating clutch member 221 to be urged firmly against the stationary braking face 229 without however being jammed too severely against it.

A relatively strong and adjustable spring 299 bearing at its lower end upon the upper end of the valve 265 in the oil chamber 293 and bearing at its upper end against a vertically adjustable stud 285 tends normally to maintain the valve tightly upon its seating 261 and therefore to prevent oil from being forced out of the cylinder 21! through the duct 269 and into the chamber 263 by the descent of the plunger 213 except when the plunger is moved downwardly at a relatively high speed (as occurs in the manner hereinafter described as soon as the trip lever 231 engages the shoulder 26| on the forward latch 245 in stopping from high speed). The precise condition under which the valve 295 will rise from the seating is of course determined by the strength of the spring 283 acting on the valve which is' adjustable by means of the stud 295. In order however to allow oil to flow freely from the chamber 263 into the cylinder 21| as the plunger 213 is raised by means of a spring 291 located between it and the bottom of the cylinder 21! on the restarting of the machine into operation in the manner hereinafter described, a pasfrom its lower end and communicates by means of lateral openings 29! at its upper end with the interior of the chamber 263. A light spring 293, seated upon an inturned rim around the lower end 'of the valve bears at'its upper end against a ball 295 and urges it upwardly against a narrowed neck in the passage 289. The ball 295 and the passage 289 constitute a one-way valve through which oil may readily flow downwardly under the suction created by the upward movement of the plunger 213 but which prevents upward flow of oil through the valve from the cylinder 21| to the chamber 263.

From what has just been said it will be appreciated'that the separation of the cooperating clutch member 221 from the pulley l3 and the pressure with which it is forced against the stationary braking face 229 are controlled by the cooperation of the trip levers 231, 239 with the latches 2 3-5, 241 and that the lateral displaceits cylinder but that, owing to the bleedvalve 219 being of relatively small diameter, the dashpot will offer a greater resistance to quick downward movement of the plunger than it will offer to comparatively slow movement of the plunger and therefore that at the instant when the clutch member 22? is first forced against the braking face 229 in stopping from high speed, the pressure exerted between these two members will be greater than at any other period in the stopping of the machine parts. It will moreover be appraciated that as the speed of the moving parts falls, the speed with which the plunger 213 is forced downwardly along its cylinder will also falland therefore the resistance offered to its movement by the dashpot will likewise fall, thus giving the result that the braking pressure exerted on the moving parts will gradually decrease in accordance with the decreasing speed of movement of the parts.

In the machine now being described means is provided to allow the cooperating clutch member 221 to be held pressed against the stationary braking face 229 for a longer portion of the final cycle of the machine when stopping from high speed than when stopping from low speed to provide ample time for the parts to be brought to rest relatively gradually.

This is effected by causing the latches 245, 241 to move towards the left of the machine (1. e. towards the trip levers) through a chosen distance when the machine is started into operation at high speed so that the trip lever 231 will engage the ,latch 245 at an early time in the final cycle of the machine and by causing the latches to move through a lesser distance in this direction (so that the trip lever 239 will engage the latch 241 at a later time in the final machine cycle), when the machine is started into operation at low speed.

lhe means for so moving the latches toward the left comprises the spring 291 aforementioned which lies beneath the plunger 213 of the dashpot, this spring acting, when the treadle l1 is depressed to start the machine into operation, to rock the bell crank lever 25l, 255 in a clockwise direction looked at from the front and thus to move the latches in the desired direction. In order to limit the extent of movement of the latches towards the left when the machine is started into operation at low speed, there is pivoted on the pin 249 on which the latches are mounted, a finger 291' which lies behind and close against the latch 241, this finger being normally upheld against the lower face of a forwardly extending stop plate 299 secured to the machine frame. This finger has an upstanding shoulder 39! (see Figure 4) which. in the sto ped position of the machine, lies a short distance away from the right hand face of the stop plate 299. When the treadle is depressed only far enough to cause the machine to run at low speed the arrangementhereinafter described which then draws the latch 241 downwardly away from the trip lever 239 does not disturb the heightwise position of the finger 291 and therefore when the latches are moved to- 7 towards the left until their movement is arrested by""co'n'tact of the arm 255 of the bell crank lever 25L 255with a fixed stop 333 on the machine frame? The arrangement above referred to for withdrawing the latches downwardlyaway from the trip levers when the treadle ill is depressed to start the machinednto operation comprises a rising and falling plate 335 held normally in a vertical position against "a 'stoplailfi (Figure 3) contacting with its right harid'face' by a spring 368; This plate hasan opening Sill cut' in it through which the lefthan'd'ends of the latches and of the finger 29,; extend. The plate 335 iss'ec'ured'to tnenppr end or a stem 35 9 which is pivotedat its lower end on a for- \vardly rearwardly extending pin 35! carried by an arm 353 which is secured on a rock'- shaft 3? whichalso carries a second arm L winch is connected by a rod Bi to the rearward end of the treadle l'ifa spring 32 (figure 1) connected at its upper end to the rod and at its lower end to a fixed pin tending to raise the plate 325 to the position shown best in th fi re he en i the Plate 3% is substantially rectangular in shape but has a downwardly projecting tongue 323 located on its uper edge, the tongue being arranged directly o t latch 2 hen th tre d H is depressed only far enough to start'the mah ne o p a on at l w s e d h ate 5 5 will be drawn downwardly far enough only to cause the tongue 323 to urge the latch 341 out of engagement with the trip lever 239, leaving posi of h l t h 5 5 in P finger Z undisturbed. As will hereinafter become clear the latch 241i alone of the two latches is in engagernent with its trip lever when the machine is stepp d an th r W hdrawal f t w t from the trip lever will allow the sprip s 2.43 to ur e he pe tin e li e membe .2" m e engagement with the pulley L3. When this latch has been withdrawn from its trip lever the spring 26'! in the dashpot will cause the latches to IQPYB t war s t e until t ey ar rre d by contact of the shoulder 3Q! on the finger 2&3] it t e st p e .9.9-

When the treadle is depressed far enough to cause the machine to run at high speed, the pertions of the upper edge of the opening an in the l'late 385 on opposite sides of the tongue 323 will be brought down sufficiently far to abut against the latch 245 and the finger 291 and to move them respectively away from the trip 1ever'23'i and the stop plate 239, the latch 2M being of course also depressed by'the tongue 323 at this time. When this has taken place the latches will be rnoved towards the left until they are arrested by the stop 3 03.

' When the treadle has been depressed only far enough to start the machine into operation at low speed (and has therefore pulled downwardly only the latch 24'!) and istherea'fter allowed to rise to bring the machine to "restfthe' latch 2H i'sfallow'ed't'o rise by gthe risingof the tongue 323 and its shoulder 259 will be engaged by the trip lever 239'when the" latter next springs towards the right. When -this occurs'the trip lever will immediately commence 'to move the latches to- Wards the right against the action of the dashpo't and the brakingeffort will immediately become operative to reduce the momentum of the movingparts'; the movement ofthe latches continuing until a face 325 on the right hand side of thearm 25i ofthe bell crank lever 25L 255 strikes against a fixed part of the machine frame "therefore arrests the further movement of the latches. The arresting of the movement of the latches causes'thecooperating clutch member g2} tobe urged somewhat more firmly, for a'vei y shortpe'riod, against the stationary braking face 229 to ensure that the parts will be brought td'rest'with the needle and awl in the desired positions out of the work.

When'howeve'r the treadle has been depressed far enough to start themachine into operation at high speed (and has therefore pulled downwardly both 'thelatche's 2 35i, 24'?) and is thereafter allowed to rise to bring the machine to rest it is desirable toavoid wearing away of the shoulder 26! of the latch 245 by the lower end of the'trip lever 23? due to premature engagement of the latch with'the trip lever and for this purpose means is provided for ensuring that the latch 245 will be allowed to engage the trip lever only when the lowerend 'of the latter occupies a position to the left" of the shoulder. The said means comprises a rearwardly extending spring pressed plunger 32? arranged in a fixed part of the machine, the" rear end of theplunger having a nose arranged, when the latch 245 has been drawn downwardly by the treadle in the starting of the machine into high speed, to project over the forward side of this latch. When the treadle is later released'the latch is allowed to rise until it is arrested by this plunger which'occupies such a heightwise position that the latch will be'maintained temporarily by it out of contact with the trip lever 23"]. The rearward latch 2 has secured 'to'its underside a forwardly projecting lug 329 (Figures 2 and 3) which is arranged, when the latch 245 is engaged'by the plunger 32?, to contact withthe underside of the latch 2&5 and thus prevent the latch 24'! from rising into contact with'the lower'endof thetrip lever 239 until the latch 2 4 5 is'released from the plunger, thus avoiding the'unnecessary wear which would take place on the upper face 'of the latch 24'! if it were allowed toabut against the trip lever 239 immediately the treadle is released.

"In order tocause the plunger 321 to release the latches 'to allow them to ride into engagement with their triplevers, the plunger is provided at the right hand side of its rear end with a bevelled face 33 l and the plate 305, which is provided with a bevellededge 333 extending upwardly along its forward edge; isarranged to be rocked to the left about the pivot 3i l' at the appropriate time to urge the plunger32l forwardly to release the latches. In order to rock the plate for this purpose, the lever 231 is provided on its lefthand face with a thickened portion 335 which when the plate occu'pies its highest position, is arranged to strike against the plate as the lower end of the trip lever 231 reaches the left hand end portion of its travel and thus rock the plate towards the left. the plate being returned to its original position as the tripdever swings back by the spring afprernentioned whichds coupled to it.

Th efclriv'in'gmechanism and the stop motion of the machine operate 'as follows: Assuming the treadle ll not to be depressed the pulley l3 on the main shaft will be driven idly at low speed by the pulley member I95 through the epicyclic gearing "on the countershaft. When the treadle is depressed only far enough to cause the machine to Operate at low speed (an indication being given to the operator when the treadle has reached this position by means of aspring 331 Figure 1 encircling the rod 3l9 abutting against a relatively fixed but adjustable stop screw 339 through which ithe rod passes) the latch 24'! is drawn downwardly away from contact with the trip lever 238 to disengage its shoulder from the trip lever (the shoulder on thelatch 2 35 being spaced away to the right in an inoperative position relatively to the trip lever 23'! when the machine is in stopped position and it being unnecessary to disturb the position of this latch at this time) and the springs 243 in the cooperating clutch member 221 will therefore act immediately to cause the cooperating clutch member to become clutched to the pulley i3 to drive the machine at low speed. Sufficient clearance is provided in the two speed driving device between the members 2535 and 99 to ensure that the partial depression of the treadle will not cause the member I95 to become clutched to the member 205.

Immediately the latch 24'! is drawn downwardly away from the trip lever 239 the spring 28'! in the dashpot will cause the latches to move smartly towards the left until the shoulder Sill on the finger 231 abuts against the stop plate 2953, this plate however being so positioned that it will arrest the movement of the latches before the shoulder 26| on the latch'245 reaches a position such that the lower end of the trip lever 23? can strike against it as this lever rocks to and fro. The parts remain in this position until the treadle is released to cause the machine to be brought to rest and when this is done the latch 24'! is immediately allowed to rise into contact with the lower end of the trip lever 23%! which latter as it next swings towards the right strikes against the shoulder 259 on the latch and therefore commences to move the latches back again towards the right. The backward movement of the latches is resisted by the dashpot which therefore causes the cooperating clutch member 221 to become unclutched from the pulley l3 and to be pressed firmly against the stationary braking face 229 whereupon the speed of the moving parts immediately begins to fall. As the speed falls, the plunger 213 in the dashpot moves more slowly down its cylinder and thus allows the bleed valve 279 to become gradually more effective to reduce the oil pressure below the plunger and thus to bring about a gradual and even decrease in the braking effort applied to the moving parts. When the parts have almost reached the positions in which it is desired that they shall be stopped the face 325 on the arm 25! abuts against its cooperating stationary face and thus brings about a momentary increase in the braking pressure which ensures that the parts will in fact be brought to rest in the desired positions. By arranging for the trip lever 239 and the latch 24? to cooperate in this manner, the braking effort may be applied to the moving parts throughout about the last one hundred and fifty degrees of the final machine cycle.

If, while the, machine is operating at low speed or while it is stopped, the treadle is fully depressed to cause the machine to operate at its high speed, the pulley member I95 on the countershaft will become clutched to the member 235 to be driven thereby at high speed and,

if the latch 24'! has not already been pulled downwardly by depression of the treadle to start the machine into operation at low speed, both the latches 245 and 241 will be drawn downwardly out of engagement with the trip levers and the finger 29? will also be drawn downwardly out of engagement with the stop plate 299. The spring 287 in the dashpot will immediately cause the latches to move towards the left a distance further than theywere moved by the spring when the machine was started into operation at low speed, until their movement is arrested by the stop 333. When this occurs, the shoulder 26| on the latch 245 will have moved so far towards the left as to occupy the same position, considered forwardly and rearwardly of the machine, as the shoulder 259 on the latch 24! occupies during the low speed operation of the machine, this latter shoulder having, of course, moved still further towards the left.

The latches remain in their downward position until the treadle is released to cause the machine to be brought to rest from high speed. When the treadle is released the latches 245, 24'! rise until they are arrested by the nose on the plunger 32?, the finger 291 also rising until that portion of its upper face to the right of the shoulder 35! abuts against the lower edge of the stop plate 259, the plate 305 continuing to its highest position (which is determined by contact of the forward portion of the treadle with a fixed but adjustable stop screw 341, Figures 1 and 2).

As previously stated, the lower ends of the two trip levers 231, 239 move continually to and fro during the running of the machine, the lower end of the trip-lever 239 moving to the left as the lower end of the trip lever 237 moves towards the right and vice versa.

When, after the plate 305 has risen to its highest position, the lower end of the trip lever 23'! next swings towards the left, the thickened portion 335 on it will strike against the plate 395 and swing it towards the left to cause the plunger 32? to be cammed forwardly to release the latches and allow them to rise into contact with the lower end of their respective trip levers. When the latch 245 thus engages the lower end of the trip lever 231, the shoulder 26I on it will rise almost into contact with the right hand face of the lower end of the trip lever (which latter will at this time be at substantially the left hand limit of its stroke) and therefore when the lower end of this trip lever next swings towards the right, its engagement with the; shoulder will cause the latches to commence also to move in this direction. Since the machine will at this time be running at its high speed, the trip lever will tend to urge the latches rapidly towards the right and thus urge the plunger 273 in the dashpot rapidly down its cylinder. As however, the bleed valve 219 in the plunger is of but a small area, the oil beneaththe plunger will offer a very firm resistance to downward movement of the plunger and will thus cause the cooperating clutch member 22'! to be moved firmly into contact with the stationary braking face 229. In order, however, that therbraking effort thus exerted on the moving parts shall not be so severe as to result in shock to the machine, the spring 283 above the central valve 265 in the dashpot will have been so adjusted that the valve can be 75.

forced upwardly temporarily away from its seating under the pressure exerted on the oil by the downward movement of the plunger, and thus relieve to a desired degree the force with which the cooperating clutch member is initially forced against the stationary braking face. As will be understood, this valve regains its seating when the pressure below the plunger diminishes to an extent which allows the valve to be forced downwardly by the spring 283.

As the trip lever 231 continues to move the latches towards the right, the braking effort will act to decrease progressively the momentum of the moving parts and, therefore, the speed with which the latches are urged towards the right and the speed with which the plunger 213 is forced downwardly along its cylinder. The more slowly the plunger descends along its cylinder, the more effective will the bleed valve 219 become in relieving the pressure on the oil beneath the plunger and, therefore, the smaller will become the resistance of the downward movement of the plunger, thus bringing about the result that a decrease in the braking effort accompanies the decrease in momentum.

The lower ends of the two trip levers move, as will be understood, through equal distances as they move to and fro and the distance which the shoulders 259, 26! are spaced apart on their latches from left to right of the machine is equal to the stroke of the lower ends of the trip levers, the shoulder 259 being further to the left of the machine than the shoulder 26!. Therefore, when the trip lever 231 has moved the latches as far towards the right as it can, the shoulder 259 on the latch 241 will have been brought into line with the right hand face of the lower end of the trip lever 239, the latch then being caused by its spring 251 to rise until the portion to the left of the shoulder rests against the end of the trip lever. The trip lever 231 then commences to retire to the left away from engagement with the shoulder 26! on the latch 245 and the trip lever 239 commences to move towards the right to continue the movement of the latches in this direction by engagement with the shoulder 259. From that time until the face 325 abuts against its cooperating stationary face to arrest the movement of the latches and ensure that the parts are actually brought to rest in the positions desired, the trip lever 239 and the latch 2 31 continue to maintain the co-operating clutch member pressed against the stationary braking face 229 under a progressively decreasing pressure through the action of the dashpot in the manner previously described with reference to the stopping of the machine from low speed.

Conveniently, the spring 283 above the valve 265 in the dashpot will previously have been so adjusted to control the resistance offered to descent of the plunger 213 that immediately the latter is urged down its cylinder at the commencement of the stopping from high speed to cause the trip lever 239 to engage the shoulder 259 on the latch 241, the speed of the parts will have been reduced substantially to the speed at which the parts will be moving when that lever engages that shoulder in the stopping of the machine from low speed in the manner hereinbefore described.

It will therefore be seen that in the stopping of the machine from high speed the two trip levers operate to impart to the latches a movement towards the right which is substantially equal in extent to twice that which they receive,

under the action of the trip lever 239 alone, in the stopping of the machine from its low speed and that, therefore, the braking effect on the machine parts will continue during a portion of the final machine cycle when stopping from high speed substantially equal to twice that during which the braking effort is effective during the final cycle when stopping from low speed, i. e. the braking effort is effective throughout about the last three hundred degrees of rotation of the final machine cycle.

In sewing around the end corners of rectangular cases or the like it is often desired to sew a single stitch actually in the corner while the machine is in operation at low speed and the stopping mechanism above described is found particularly suitable for allowing the machine to insert single stitches in the work since it operates to bring the machine to rest in a very smooth and shock-free manner with the parts in precisely the positions desired.

Moreover, the pressure exerted by the trip lever 239 on the shoulder of the latch 241 as the machine actually comes to rest will be so light as to require but a small effort. to pull this latch awayv from the trip lever in the starting of the machine, this being a matter of considerable advantage in a machine, such as is described above, which is often required to insert single stitches in successive corners of the work and which, therefore, may require to be tripped a number of times when sewing rounda single case or the like.

Such a stopping mechanism as is just above described may be found of advantage not only in machines which are particularly arranged to sew together parts of suit cases or the like, but also in other machines which are arranged to ron at high speed such, for example, as boot and shoe outsole sewing machines of the type disclosed in Patent No. 2,056,670 or of other similar types.

The sewing machine disclosed in this application, as originally filed, forms the subject-matter of divisional application Serial No. 200,635 filed April '7, 1938.

The nature and scope of the invention having been indicated, and a machine embodying the several features of the invention having been specifically described, what is claimed is:

l. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley for causing the driven shaft to be rotated, a brake for bringing the driven shaft to rest, and mechanism actuated by the driven shaft when set into operation to apply the brake with a progressively decreasing effort.

2. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley for causing the driven shaft to be rotated, a brake for bringing the driven shaft to rest, and mechanism actuated when set into operation toapply the brake with an effort decreasing progressively with the speed of the driven shaft.

3. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley for causing the driven shaft to be rotated, a brake for bringing the driven shaft to rest, mechanism actuated by the driven shaft when set into operation to apply the brake with a progressively decreasing effort, and means for finally bringing the driven shaft to rest at a predetermined position.

4. A driving and stoppingv mechanism having,

in combination, a driven shaft, a main driving pulley for causing the driven shaft to be rotated, a brake for bringing the driven shaft to rest, a cam on the driven shaft, a lever operated by the cam, connections for causing the cam lever to actuate the brake, and means for progressively decreasing the effectiveness of the connections in applying the brake as the speed of the driven shaft is reduced.

5. A driving and stopping mechanism having, in combination, a driven shaft, a driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the cam, means for restraining the lever to cause the clutch member to be disengaged from the driving pulley and engaged with the brake member, and means for progressively decreasing the restraining effort of the restraining means as the speed of the driven shaft is reduced.

6. A driving and stopping mechanism having, in combination, a driven shaft, a driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the cam, a dashpot, and means connected to the dashpot for restraining the lever to cause the clutch member to be disengaged from the driving pulley and forced against the brake member with an effort decreasing as the speed of the driven shaft is reduced.

7. A driving and stopping mechanism having, in combination, a driven shaft, a main driving clutch for causing the driven shaft to be rotated, a brake for bringing the driven shaft to rest, means actuated when the shaft reaches a predetermined position to render the main clutch member inoperative and to apply the brake when the shaft is rotated at one speed, and means actuated to apply the brake at another predetermined position of the shaft when the shaft is rotated at a different speed.

8. A driving and stopping mechanism having, in combination, a driven shaft, a driving pulley on the shaft, a brake for bringing the shaft to rest, means including a treadle for causing the shaft to be driven by thedriving pulley at a number of diiferent speeds, and connections controlled by the treadle for applying the brake during a. greater angular rotation of the shaft when the shaft is rotated at high speed than when the shaft is rotated at low speed.

9. A driving and stopping mechanism having, in combination, a main driven shaft, a driving pulley on the shaft, a brake for bringing the shaft to rest, a counter shaft connected to rotate the driving pulley, a treadle for causing the main shaft to be connected or disconnected from the driving pulley, mechanism controlled by the treadle for rotating the counter-shaft at either of two speeds, and connections controlled by the treadle for applying the brake during a greater angular rotation of the shaft when the shaft is rotated at high speed than when the shaft is rotated at low speed.

10; A driving and stopping mechanism having, in combination, a driven shaft, a driving pulley on the shaft, means including a treadle for causing the shaft to be driven by the driving pulley at a number of speeds, a brake for bringing the shaft to rest, a dashpot for controlling the operation of the brake, and connections actuated by the treadle for changing the effect of the dash pot on the brake according tothe position of the treadle.

11. A driving and stopping mechanism having, in combination, a driven shaft, a driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the cam, a dashpot, a piston in the dashpot, means connected to the piston for restraining the lever to cause the clutch member to be disengaged from the driving pulley and forced against the brake member as the piston is moved by the lever, and means for changing the range of relative movement between the piston and the dashpot required to bring the main shaft to rest at a predetermined position when driven at different speeds.

12. A driving and stopping mechanism having, in combination, a driven shaft, a driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the cam, a dashpot, a piston in the dashpot, means connected to the piston for restraining the lever to cause the clutch member to be disengaged from the driving pulley and forced against the brake member as the piston is moved by the lever, means including a treadle for causing the driving pulley to drive the shaft at a number of different speeds, and connections actuated by the treadle for changing the range of relative movement between the piston and dashpot required to bring the main shaft to rest at a predetermined position when driven at said different speeds.

13. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the cam, a latch for restraining the movement of the lever to cause the clutch member to be disengaged from the driving pulley, and engaged with the brake member, a carrier for the latch, and a dashpot for resisting movement of the carrier.

14. A! driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the cam, a. latch for restraining the movement of the lever to cause the clutch member to be disengaged from the driving pulley, and engaged with the brake member, a carrier for the latch, a dashpot for resisting movement of the carrier, a treadle for releasing the lever from the latch, and connections actuated by the treadle to change the movement resisting effect of the dashpot.

15. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, levers oscillated by the cam, latches for restraining the movements of the respective levers to cause the clutch member to be disengaged from the driving pulley and engaged with the brake member, a

movable carrier for the latches, a dashpot for resisting movement of the carrier, a treadle,mechanism actuated when the treadle is depressed to rotate the driving pulley at different speeds, and latch actuating connections controlled by the treadle when the driving pulley is rotated at low speed to cause the carrier after the treadle is released to be moved by the oscillating levers a predetermined distance in stopping the driven shaft, and when said mechanism rotates the driving pulley at a higher speed, to cause the carrier to be moved by the oscillating levers a greater distance in stopping the driven shaft.

16. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake mem ber, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, levers oscillated alternately by the cam, latches for restraining the movements of the respective levers to cause the clutch member to be disengaged from the driving pulley and engaged with the brake member, a carrier for the latches, a dashpot for resisting movement of the carrier, treadle, mechanism actuated when the treadle is depressed to rotate the driving pulley at different speeds, and latch actuated connections controlled by the treadle when the driving pulley is rotated at low speed to cause the carrier after the treadle is released to be moved by one only of the oscillating levers in stopping the driven shaft, and when the driving pulley is rotated at higher speed to cause the carrier to be moved successively by said levers in stopping the driven shaft.

1'7. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to. the clutch member, levers oscillated alternately by the cam, latches for restraining the movements of the respective levers to cause the clutch member to be disengaged from the driving pulley and engaged with the brake member, a carrier for the latches, a dashpot for resisting movement of the carrier, a stop plate, a stop latch on the carrier for engaging the stop plate to hold the carrier in predetermined position, a treadle, mechanism actuated when the treadle is depressed to rotate the driving piuley at different speeds, and latch actuating connections controlled by the treadle when the driving pulley is rotated at low speed to cause the carrier, after the treadle is released, to be moved by one only of said levers in stopping the driven shaft and, when the driving pulley is rotated at higher speed, to release the stop latch from the stop plate and cause the carrier to be moved successively by the oscillating levers in stopping the driven shaft.

13. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, levers oscillated by the cam, latches for restraining the movements of the respective levers to cause the clutch member to be disengaged from the drivingpulley and engaged with the brake member, a movable carrier for the latches, a dashpot for resisting movement of the carrier, a treadle, mechanism actuated when the treadle is depressed to rotate the driving pulley at different speeds, and connections controlled by the treadle when the driving pulley is rotated at low speed to locate the carrier in a position in which it will be moved after the treadle is released by one only of the levers in stopping the driven shaft and, when the driving pulley is rotated at higher speed, to locate the carrier at a position in which it will be moved successively by the oscillating levers in stopping the driven shaft.

19. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the cam, a latch for restraining the movement of the lever during its movement in one direction to cause the clutch member to be disengaged from the driving pulley and engaged with the brake member, a treadle for releasing the lever from the latch, and means for preventing the latch from engaging the lever during movement of the lever in the other direction.

20. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the cam, a latch for restraining the movement of the lever during its movement in one direction to cause the clutch member to be disengaged from the driving pulley and engaged with the brake member, a treadle for actuating the latch to permit the latch to engage or disengage the lever, means engaging the latch to prevent the latch from engaging the lever prematurely.

21. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the cam, a latch for restraining the movement of the lever to cause the clutch member to be disengaged from the driving pulley, and engaged with the brake member, a carrier for the latch, a dashpot for resisting movement of the carrier, and means for limiting the resistance with which the dashpot acts.

22. A driving and stopping mechanism having, in combination, a driven shaft, a main driving pulley on the shaft, a stationary brake member, a clutch member on the shaft arranged to engage either the driving pulley or the brake member, a cam connected to the clutch member, a lever oscillated by the earn, a latch for restraining the movement of the lever to cause the clutch member to be disengaged from the driving pulley, and engaged with the brake member, a carrier for the latch, a dashpot for resisting movement of the carrier, and a spring loaded valve connected with the dashpot for limiting the resistance with which the dashpot acts.

23. A driving and stopping mechanism having, in combination, a driven shaft, a pulley on the shaft, a driving mechanism for rotating the pulley at high or low speeds, a ratchet wheel in said mechanism, a pawl engaging said ratchet wheel to permit the ratchet wheel to rotate in one direction relatively to the pawl when the pulley is rotated at high speed and to hold the ratchet wheel when the pulley is rotated at low speed, and friction means for actuating the pawl out of engagement with the ratchet wheel when the wheel is rotated relatively to said pawl.

24:. A driving and stopping mechanism having, in combination, a driven shaft, a constantly rotating countershaft, a driving pulley on the counter-shaft for rotating the driven shaft, pinions on the driving pulley, a gear or counter-shaft engaging the pinions, an internal gear surrounding the pinions, a ratchet wheel on the internal gear, a spring pressed pawl engaging the ratchet wheel to hold the internal gear from rotation in a direction opposite from that of the countershaft, a clutch member for driving the internal gear in the same direction as the'counter-shaft, and a friction producing element on the pawl engaging the internal gear to throw the pawl out of engagement with the ratchet wheel when the internal gear rotates in the same direction with the counter-shaft.

25. A driving and stopping mechanism having, in combination, a driven shaft, a pulley on the shaft, a driving mechanism for rotating the pulley at high or low speeds, a spring actuated treadie for controlling the speed at which the driving mechanism rotates the pulley, yielding means connected to the treadle for indicating to the operator by a marked increase in pressure required to operate the treadle whenever the treadle is moved from low speed to high speed position,

and means for regulating the position of the of the respective levers to cause the clutch member to be disengaged from the driving pulley and engaged with the brake member, a carrier on which the latches are mounted with their shoulders spaced from each other in the direction of lever oscillation a distance substantially equal to the stroke of said levers, means for resisting movement of the carrier, and means for suitably positioning the carrier to cause one or both of the latches tobe engaged by the levers.

JOSEPH GOULDBOURN. THOMAS AUBREY KESTELL.

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