US1791176A

US1791176A - Driving and stopping mechanism

Info

Publication number: US1791176A
Application number: US92736A
Authority: US
Inventors: Laurence E Topham
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1926-03-06
Filing date: 1926-03-06
Publication date: 1931-02-03
Anticipated expiration: 1948-02-03

Description

Feb. 3, 1931. V 1 TOPHAM 1,791,176 I DRIVING AND STOPPING MECHANISM Filed March 6, 1926 9 Sheets-Sheet l Feb. 3, 1931'. 1.. E. TOPHAM DRIVING Am) STOPPING MECHANISM 9 Sheets-Sheet 2 ,17 7.; I M MWW Filed March 6, 1926 v A f Feb. 3, 1931.

L. E. TOPHAM DRIVING AND STOPPING MECHANISM Filed March 6. 1926 9 Sheets-Shee't 5 mess fivemr M 6? 67 14; 4

Feb. 3, 1931. L. E. TOPHAM 1 DRIVING AND STOPPING MECHANISM 9 Sheets-Sheet 4 Filed March 6 L; @345 w /u Feb. 3, 1931. L. E. TOPHAM 1391,1 1

' muvme AND swormemcnmsu Filed March e; 1926 9 Sheets-Shed 5 mamas fipenior W/wf 7 a aimff Feb. 3, 1931.- E. TOPHAM DRIVING AND STOPPING MECHANISM Filed March 6, 1926 9 Sheets-Sheet 6 Feb. 3, 1931. TOPHAQM 1,791,176

DRIVING AND STOPPING MECHANISM Filed March s, 1926 QSheets-Sheet 7 Feb. 3, 1931. E. TOPHAM 39 9 DRIVING AND STOPPING MECHANISM 7 Filed March 6, 1926 9 Shets-Sheet "8 jjig jl J.

3,12%6355 I I T I a? 2/?- J/% v 4%??? Feb. 3, 1931. 1.. E. TOPHAM DRIVING AND STOPPING MECHANISM 9 Sheets-Sheet 9 Filed March 6,' 1926 Patented Feb. 3, 1931 UNITED STATES:

JERSEY Application filed. March 6,

The invention relates to driving and stopping mechanisms adapted for use in high speed machines.

The object ofthe invention is to provide novel and improved mechanism by which a undue shock and wear upon the parts.

Driving and stopping mechanisms have heretofore been devised which comprise a high speed driving mechanism for driving a machine or mechanism during its normal oporation, and a slow speed driving mechanism which is thrown into operation just before the machine is to be stopped and which acts to drive the machine at a predetermined slow speed to stopping position.

To secure the results attained by these high and low speed driving and stopping mechanisms, but in a much simpler and more efficient manner, a feature of the present invention contemplates the use of an electric motor for driving the machine, means for disconnecting the machine and motor to permit the machine to be finally stopped and means for reducing the speed of the motor to cause the machine to be driven by the motor at a predetermined low speed prior to the final stopping.

1 As herein shown the invention is embodied in a mechamsm 1n whlch current s supplied to the motor through a high and low speed switch, said switch being moved to low position when the machine isto be stopped and I being controlled in such a manner that the means for disconnecting the machine and motor will not be rendered operative until after the machine is being driven at the low speed.

Also, as herein shown, the present invention is embodied in a mechanism in which the slowing down or retardingof the machine from the high to the low speed is accomplished by the drag on'the armature or rotor of the motor due to the alteration in its electroeynamic torque by the change in the conditions in the motor produced by the shift of the switch from high to low speed position PATENT OFFICE manner en E. rornnra, or WEnHArr, MASSACHUSETTS, nssienon To UNITED SHOE MACHINERY CORPORATION, or PATERSON NEWJERSEY, AconroRA'rron or NEW DRIVING AND STOPPING MECHANISM 1926. Serial No. 92,736.

and thus the necessity of intermediate gearing or brakes such as have heretofore been used in high and low speed stopping mechanisms to secure this result is avoided.

In. accordance with another feature of the invention, the means for disconnecting the machine and motor to permit the machine to be finclly stopped is arranged to actin timed relation to a driven shaft of the m achine and after at least a predetermined in-- terval ofslow speed conditions in the motor caused by the movement of the switch to low speedvposition. 7 y I I Another feature ofthe invention contemplates the provision of means whereby .as the machine is brought to a stop the switch is moved again to high speed position so that the motor vruns at high speed at all times except when .the stopping mechanism is in operation and no shift from low to high is required in starting.

Other features of the invention consist in the combinations, devices, and arrangement of parts hereinafter described and claimed. Among these features is a novel and improved clutch actuating and controlling mechanism which is well adapted for use in driving and stopping mechanisms which donot comprise both a high and a low speed driving mechanism, as well as in high and low speed driving and stopping mechanisms which comprise either slow speed gearing or a high and low speed electric motor.

7 -The invention together withv the advantages obtained thereby will be readily understood by those skilled in the art from the following description taken in connection with the accompanying drawings which illustrate one embodiment of theinvention applied to the machine disclosed in application ofthe with, the parts being shown in the positions 7 which they assume when the machine is at rest. Fig. 2 is a right'side elevation of the parts shown in Fig. 1. Fig. 3 is a sectional plan view of the parts shown in Fig. 1. Fig. 4 is a detailed front view partly in section of a portion of the mechanism shown in Fig. 1, but with the parts in the position they assume when the machine is running. Fig. 5 is a right side elevation of certain of the parts shown in Figs. 1. and i. Fig. 6 is a left side elevation of certain portions of the stopping mechanism including the high and low speed switch and its controlling mechanism with the machine in rest position. Fig. 7 is a detailed front elevation of certain portions of the stopping mechanism with the parts in the positions they assume immediately after the mechanism is thrown into operation by the elevation of the control into engagement with its actuating lever. Fig. 8 is a. right side elevation of certain of the parts shown in Fig. 7. Fig. 9 is a front elevation. of the same parts showing the control bar further advanced and with the slow speed switch thrown in. Fig. 10 is a right side elevation of certain of the parts as shown in Fig. 9. Fig. 11 is afront elevation of the parts illus trated in Fig. 9 showing the control bar advanced to throw into operation the mechanism by which the clutch is thrown out and the brake set to bring the machine to its final stop. Fig. 12 is a right sideelevation of certain of the parts as shown in Fig. 11. Fig. 13 is a detailed front elevation of parts of the stopping mechanism advanced slightly beyond the positions indicated in Figs. 11 and 12 and illustrating particularly the mechanism for disengaging the control bar from its actuating lever. Fig. 1 1 is a right side elevation of certain of the parts, including the high and low switch, in the position shown in Fig. 13. Fig. 15 is a detailed front view of the parts shown in Fig. 18 with the control bar at the limit of its advancing stroke and about to return to starting position. At this time the switch has returned to high speed position. Fig. 16 is a right side elevation of parts of the high and low switch mechanism prior to the return of the control bar and with the switch in, high speed position.

The driving and stopping mechanism hereinafter specifically described includes a main driving shaft, an electric motor connected thereto adapted to be driven at high or low speed, sleeve loosely mounted on the shaft and arranged to be connected thereto by a friction clutch and gearing connecting the sleeve with the cam shaft of the machine which is to be driven. A flange formed on the upper end of the sleeve carries one face of the friction clutch which is adapted to enga e a corresponding clutch member formed on the driving shaft. A heavy spring bearing against the lower end of the sleeve tents to hold the clutch members in engagement. The sleeve is also adapted to cooperate with the stationary member of a friction brake so that when the sleeve is forced downward against the pressure of its spring the clutch is disengaged and the braling surfaces are brought into contact to stop the machine. A cam groove formed in the sleeve and adapted to engage lock bolt carried on one end of a bell crank lever forms a convenient means for controlling the position of the sleeve.

The high and low switch for controlling the speed of the motor comprises a switch lever adapted to swing between the high and low speed positions and actuated by means of a switch cocking device which is set to swing the switch lever to the low speed position when the machine is started, and is set to return the switch lever to the high speed position when the clutch is thrown out in stopping the machine. At all times except when the stopping mechanism is in operation, the switch is locked in high speed position against the pull of the switch cocking device.

The operation of the switch mechanism and the clutch and braking mechanism is controlled and coordinated by means of a control bar which is actuated, when thrown into operation, by means of a lever continuously oscillated from a cam groove in the clutch sleeve. To stop the machine the oscillating lever is operatively connected to the normally inactive control bar which is lifted by successive steps and acts first to throw the motor into slow speed and then after about two revolutions of the cam shaft to throw into operation mechanism for disconnecting the clutch and applying the brake. As the machine stops the motor is again returned to high speed and the control bar permitted to drop back to its original inoper ative position.

Referring to the drawings, a shaft, indicated at 18 has loosely mounted thereon a sleeve 20 which is directly connected to the cam shaft of the machine through a spiral gear 22 mounted on the sleeve and a similar gear on the cam shaft. A flange 24- formed on the upper end of the sleeve carries one face of a conical friction clutch the other member of which, indicated at 26, is mounted on said shaft 18 which is driven from the electric motor through a pinion formed on the lower end of the armature shaft 19 of the motor which meshes with an internal gear formed on an upward extension of the clutch member 26. A heavy compression spring 28 hearing against the lower end of the sleeve tends to hold the clutch members in contact. The outer surface of the flange 24 forms one member of a friction brake, the opposing surface. indicated at 29, being lined in the machine frame. It will be seen that as the sleeve is moved downward against the pressure of the spring 28 the clutch is disengaged and the braking surfaces are brought into contact to bring the sleeve and cam shaft connected thereto to a stop. p

The mechanism for disengaging the clutch and applying thebrake to stop the'cam shaft at the proper time comprises a cam groove.

formed in the sleeve 20 and arranged to be engaged by a lock bolt 32 slidably mounted in a sleeve 34 on one arm of a belljcrank lever 36 which is mounted on a rock shaft 38. A spring 40 coiled about the lock bolt inside the sleeve 34 with one end resting against a shoulder in the sleeve and the other end bearing against a shoulderon the lock bolt tends to hold the lock bolt in engagement with the cam groove. When the machine is at rest as in Figs. 1, 2 and 3, the bell crank lever, acting in conjunction with the cam groove 30, is held in a position to hold the sleeve 20 downward against the pressure of its spring with the clutch released and the brake set by means of a latch lever 44 which is notched to engage the lower end of the bell crank lever 36. A

compression spring 46 tends to hold'the latch lever in locking position.

For starting the machine; mechanism is.

- of the lever 52 and at its lower end slidably mounted in the machine frame. The lever 52 is pivoted at 54 and is connected by means of a pin and slot connection'56 at its other end to the vertical bar 58 for cooking the high and low speed switch. When the machine is at rest, the spring 60 stretched from the'rod 48 to a point on the machine frame holds the rod in an elevated position, the upward movement being limited by theengagement of a nut 62 on the lower end of the rod with a projection on the machine frame. Two parallel arms 64 extend downwardly from the hub of lever 52 into engagement with the shoulder 42 onthe rear end of the lock bolt 82 so that by depressing the rod the lock bolt may be withdrawn from the cam groove in the sleeve to permit the engagement of the clutch. The rod 48 is depressed by the operator to start the machine either by means of a hand lever 63 pivoted at 65 on the frame and connected at 6? by a pin and slot connection to the rod, or by a foot treadle through connections which include the plunger 69 and angle lever 71 pivoted at 73 to the frame The rod is then held'in its depressed position by the engagement of a latch lever 66 mounted on the machine frame and pressed downwardly by the action of its spring 68 with a catch 70 on the upper part of lever 52.

When the rod 48 is depressed to start the machine a block 72 adjustably mounted on the rod is brought into contact with and depresses the latch lever 44 to re lease the bell crank 36which is then turned about its pivot by the spring 74 stretched uetween tne lower arm of the lever and a point on the machineframe. The exact posi the frame.

From this p tion of the bell crank lever and the lock bolt while th'e'machine is running is determined by an adjustable screw 76 in the lower arm of the lever which engages an abutment 78 on The control bar of the stopping mechanism is ac uated when the stopping mechanism is thrown into operation by means of a lever 80 pivoted at 82 on the machine frame and continuously oscillated by the engagement of the roll 84 mounted on one end of the lever with the cam groove '30 in the clutch sleeve.-

It pawl 86 is mounted to slide in arecess in the other end of the lever 80, and 1s thrust -into"engagcmentwith the stopping mecha-' nism control bar 88 by means of a spring 90 wrapped around the shank of the pawl in the recess and lit-earingagainst a shoulder 92 on the pawl. To prevent the pawl from turning in its r cess, the pawl is equipped'with two pins 94 which project through slots 96 in the lever 80. lhecentrol bar 88 is mounted to slide vertically in the machine frame-in

brackets

104 and 106 and has three notches indicated at 108 to be by the pawl 86 of the'actuating lever 80. Normally thefcontrol'bar 88 is held in its lowest position by means of a spring 110 tastened/at one end to a pin 112 on the bar ai'uil the other end to a projection 114 on V the bracket 106 so that the pawl 86is' out of engagement with the notches and rideson a smooth portion of the bar. The lower extremity of the bar is in the form of awedge to engage a V shaped holder 116 on one end of the lever 118.

The stopping mechanism of the machine is thrown into operation automatically by means more fully disclosed in application, Serial No. 312,366 hereinbefore referred to, acting through intermediate connections including the link 120 and lever 122 to move the lever 118 one way or the other causing the control bar to slide up the in'clinedsurface of the holder 116 so that the upper notch 108 is brought into a position to be engaged by the pawl 86 onthe oscillating lever 80. it the control bar is raised step by step to p orni the various operations'to stop the ma'c after which itis released "from its 9.051151tlIlQnlQCllMllSn] and permitted to drop again to its original position. To prevent the bar from sliding back during each retracting strolre of the actuating lever 80,

a pawl 124 is pivotally mountedat 126 on the frame of the machine to engage successively the notches 128+1nd 130 fornied in the control bar. A sprir fastened at one end to a pin 184 on thepawl and'at the other end to the machine fraine normally holds the pawl in operative position. An arm 136 formed on the hub of the pawl'l24 is adapted slide in a recess 138 out inthe control bar,

and is also connected at 140 to the lower end of a. link 142 which is mounted at its upper end to slide between a stationary pin 14:4 and a pawl releasing device 145 consisting of a bail shaped member pivoted on the frame and provided with fingers projecting downwardly in front of the laterally projecting pins 94 of the pawl 86. As the control bar is raised to its most advanced position, the arm 136 comes into contact with the lower end of the recess and is turned about the pivot 126 swinging the pawl away from the control bar and causing the link 1&2 to wedge the pawl releasing device 145' outward to release the control bar from the influence of the pawl 86 mounted in the actuating lever 80. As the control bar drops to its original position, the arm 186 engages the upper end of the recess 188 and is swung downward returning the pawl 12-4 and the link 142 to their first positions.

The electric motor for driving the machine, the armature shaft of which motor is indicated at 19 may be of any usual or well known construction which adapts it to run at either a high or a low speed. Also except for its controlling and actuating mechanism the high and low speed switch for the motor may be of any usual or suitable construction. A. type of motor and arrangement of high and low speed switch contacts which may be used is disclosed in applicants pending application for a driving and stopping mechanism filed September 24, 1925, Ser. No. 58,352. In the construction illustrated in the drawings, the high and low speed switch comprises an actuating arm or lever 146 secured to the inner end of a shaft 148 the outer end of which carries the movable contact or contacts of the switch arranged to cooperate with the stationary contacts. The arm 146 is provided with a crosspiece 150 formed on its lower end and having right angled extensions at its extremities to engage the high and low speed stops 152 and 154: respectively and cooperate with pins 156 on the control bar 88 as will be described.

A switch cocking device is provided consisting of a lever arm 158 mounted on the pivot 160 in the machine frame and controlled by a gear segment 162 formed on the hub ofthe arm 158 and a rack 164i on the switch cock bar 58. A tension spring 166 is stretched between the switch cocking arm 158 and a pin 168 on the switch lever 1 16 to exert the required pull to cock the switch.

lVhen the rod 48 is depressed to start the machine the lever 52 is turned about its pivot to raise the switch cock bar 58 and cause the lever arm 158 to swing about its pivotand exert the desired pull tending to swing the switch to low speed position.

In operation the control bar 88 acts in conjunction with the actuating lever 80 a timing device to switcn the motor into slow speed and then after a predetermined period to throw into operation the clutch releasing and braking mechanism. The posi tion of the parts at the end of the first step in the cycle of operations immediately after the control bar has been lifted into engagement with the lever and pawl 86 is illustrated in Figs. 7 and 8 of the drawings.

During the first effective stroke of the actuating lever 80 after the control bar has been lifted as illustrated in Figs. '4' and 8, the upper pin 156 is withdrawn from the path of the switch lever which is then permitted to spring into contact with the low speed terminal under the influence of the switch cocking device. The changed conditions which result in the motor alter the electro-dynamic torque so as to produce a braking or retarding effect which operates quickly and smoothly to reduce the machine to the desired low speed. In Figs. 9 and 10, the parts of the stopping mechanism are shown in their relative positions after the completion of this operation when the motor is running at slow speed and the actuating lever 80 has begun its second upward stroke.

The second stroke of the lever 80 raises the upper end of the control bar 88 into contact with the latch lever 66 to lift it out of engagement with the catch 70 and set in motion the clutch and braking mechanism. At the same time the lower pin 156 on the control. bar is lifted into the path of the switch lever looking it for the moment in low speed position. The lever 52 and rod 4-8 released from the control of the latch lever are free to move under the influence of spring into rest position releasing the lock bolt 3:2 and latch lever l so that the bell crank lever 36 and cam groove 30 will cooperate to throw out the clutch. and apply the brake in the manner hereinafter described. The switch cock bar 58 fastened to the end of lever 52 is moved downward to cock the switch exerting a tension to return it to high speed position. The relative positions of the parts at this time is shown in Figs. 11 and 12 with the actuating lever 80 about to begin its next effective stroke.

The third effective stroke of the lever raises the control bar to its most advanced position lifting the lower pin 156 out of the path of the switch lever 146 to allow it to return to high speed position and at the same time operating the devices for disconnecting the control bar from its aetuat. mecha- (See Figs. 13, 14. 15 and As the control bar is: lifted, the lower end of the slot 138 in the bar is brought in contact with the arm 136 and acts to turn it about its pivot to throw the pawl 124 away from the control bar and also to raise the link 142 causing the pawl 86 in the end of the actuating lever 80 to be forced out of contact with the control bar. The control bar is now drawn down by its spring 110. As the bar reaches its original inoperative position, the

upper end of the slot 138 engages and turns the lever arm 136 about its pivot so that the awl 124 is swung back into contact with the barv and the link 142. retracted to permit the pawl86 to ride again on the smooth portion of the ban w The manner in which the'bell crank lever '36 and cam groove cooperate to throw out the clutch and apply the brake will be readily understood from an inspection of Figures 1, 3, 5, and 6. lVhile the machine is running, theparts are in the positions illustrated in Figures 3, 4, and 5,. with the lock bolt 32 out of engagement with the cam groove, which position of the lock bolt may be termed its normalposition. When the, latch lever 66 is moved out of engagement with the catch 7 O, the rod 48 is allowed to move upwardly and thereby the latch lever 44, best shown in Figure 5, is allowed to rest against the lower end of the vertical arm of the bell crank lever 36. Also, as the rod 48 moves upwardly, the lever 52 is swung in a counter-clockwise direction and its arms 64' release the lock bolt 32 so that thelockbolt is pressed towards the left, asviewed in Figures 3 and 4, by'the spring 40. The end of the lock bolt 32 bears against the'sleeve 20 and as the sleeve with its cam groove 30 continues to rotate, a portion of the cam groove will be caused to reg-V ister with the lock bolt which will be forced into the cam groove. As'the sleeve with'its cam groove continues its rotation, the bell crank lever 36 carrying the loolrbolt will be actuated so that its vertical arm is moved towards the-left, as viewed inlFigure 5. This movement towards the left will permit the latch lever44 to move upwardly so that its shoulder will be in a position to engage the lower end of the bell crank upon its return movement. As the sleeve with its cam groove 3Qcontinues its rotation, the movement of the bell crank lever 36 will be reversedand before this reverse movement is completed, the movement of the bell crank will be stopped by the engagement of the lower end of the vertical arm of thebell crank with theshoulder of the latch 44, The bell crankwill now be held stationary, and duringthe continued rotationof the sleeve20 with its cam groove 30 the sleeve will be movedbodily in an axial direc tion against the force ofthe spring 28, (see- Figure 1) soasto disengage the

clutch members

24 and 26. I 7 To enable the stopping mechanism to be thrown into operation manually, a lever 170 is pivotally mounted on the frame of the machine and is provided at one end with a handle and at the other end with a surface arranged to engage the lower pin 156 on the controller bar and lift the bar when the lever is actuated manually against thetension of its retracting spring 17 2. Thenature and object of the present invention having been indicated and a mechanism what is'claimed is: 1

- ing, in

I driventhereby, means for supplying current embodying'the several features ofthe invention having I been specifically described,

1. A driving and stoppingmechanism having, in combination, an electric motor, means for supplying current to the motor, a shaft driven by the motor, means'forreducing the speed of the motor to cause the driven at a predetermined low speed and means for thereafter disconnecting the shaft from the motor. a c r 2. A driving and stopping mechanism having, in combination, an electric motor, means for supplying current to the motor, means for changing the conditions in the motor to alter its electrodynamic torque and means for thereafter disconnecting the shaft from the motor. 7

3. A driving and stopping mechanism'havring, in combination, an electric motor, means for supplying current. to themotorincluding a high and low speed switch, means for movingthe switch from high to low speed position and means acting automatically at least a predetermined interval after the move 5;

ment of the switch'to'low speed position to disconnect-the shaft from theimotor.

4 A driving-andstopping-mechanism having, incombination, an electric motor, means for supplying current to the motor,'a shaft driven bythe motor, means rendered; operative in stopping the, machine for changing the conditions in-the motor to alter its electrodynamic torque, and means acting automatically thereafter from the motor.

to disconnect the shaft shaft to be 5,. A driving and stopping mechanism havto alter the 6. A driving and stopping mechanism having, in combination, an electric motor, a shaft driven thereby,

and after at least a predetermined period of low speed conditions to disconnect the shaft. 7. A driving and stopping mechanism having, in combination, anelectric'motor, a shaft driven thereby, means for supplying current to the motor, means for changing the conditions in the motor to cause it'to runat a high or low speed, and means acting in timed relat-ionto'the angular position of the shaft and after the changeeto low speed conditions to disconnect the shaft. r

8. A driving and stopping mechanism havcombination, an electric motor, a shaft to the motor including a switch, means acting operation to I and means acting aumeans for changing the con 1 dltions 1n the motor to cause t to run at when thrown into operation to operate the switch to cause the motor to operate at slow speed and means acting automatically while the motor is operating at slow speed to stop the shaft.

9. A driving and stopping mechanism having, in combination, an electric motor, a shaft driven thereby, means for supplying current to the motor including a high and low speed switch, means actuated by the shaft and acting when thrown into operation to move the switch from high to low position and after a predetermined the shaft.

10. A driving and stopping mechanism having, in combination, an electric motor, a shaft driven thereby, means for supplying current to the motor including a high and low speed switch, means actuated by the shaft and acting when thrown into operation to move the switch from high to low position and thereafter to disconnect and stop the shaft.

11. A driving and stopping mechanism having, in combination an electric motor, a shaft driven thereby, means for suppl ing current to the motor including a high and low speed switch, an actuating lever for the stopping mechanism continuously operated in timed relation to the shaft, mechanism acting when operatively connected to the actuating lever to throw the switch into low speed and thereafter to disconnect and stop the shaft, and meansfor causing this mechanism to be engaged by the actuating lever to stop the machine' 12. A driving and stopping mechanism having, in combination, an electric motor, a shaft driven thereby, means for supplying current to the motor including a high and low speed switch, an actuating lever for the stopping mechanism continuously operated in timed relation to the shaft, a control bar normally inactive, and means for causing the actuating lever to movethe control bar to change the switch to low speed and thereafter to disconnect and stop the shaft.

13. A driving and stopping mechanism having, in combination, an electric motor, a

shaft driven thereby, means for supplying current to the motor including a high and low speed switch, a clutch and braking mechanism for the shaft, a control bar acting when actuated to change the switch to slow speed position and after a predetermined period to set in motion the clutch and braking mecha nism' to stop the shaft, and thereafter to return the switch to high speed position and means for actuating the'control bar.

14. A driving and stopping mechanism having, in combination, an electric motor, a shaft driven thereby, means for supplying current to the motor including a high and low speed switch, 'a'clutch and braking mechanism for the shaft, a control bar acting when actuated to change the switch to slow speed period to disconnect and stop,

position and after a predetermined period to set in motion the clutch and braking mechanism to stop the shaft, and means for actuating the control bar.

15. A driving and stopping mechanism having, in combination, an electric motor, a shaft driven thereby, means for supplying current to the motor including a highand low speed switch normally set at high speed, a clutch and braking mechanism, a switch cocking device, means acting when the clutch is thrown in in starting the machine to cock the switch for low speed and thereafter when the clutch is thrown out in stopping the machine to cock the switch for high speed, a control bar actingwhen thrown into operation to permit the switch to move to slow speed position, and thereafter to cause the clutch and braking mechanism to stop the shaft and finally to permit the switch to return to high speed position and means for actuating the control bar. 16. A driving and stopping mechanism having, in combination, an electric motor, a shaft driven thereby, means for supplying current to the motor including a high and low speed switch, an actuating lever continuously oscillated in timed relation to the shaft, a switch cocking device, a control bar acting when operatively connected'to the actuating lever to permit the switch to move to slow speed position and thereafter while the motor is operating under low speed conditions to disconnect and stop the shaft, and finally to permit the switch to return to high speed position and means rendered active in stopping the machine to cause the control bar to be actively connected to its actuating lever.

17. A driving and stopping mechanism having, in combination, a shaft, driving mechanism therefor, means for discennecting the driving mechanism from the shaft comprising a rotatable and axially movable cam acting during its axial movement in one direction to disconnect the driving mechanism from the shaft and during its movement in the opposite direction to connect the driving mechanism with the shaft, a spring for moving the cam axially to' connect the driving mechanism with the shaft, a member nor 'mally disconnected from the cam, means for connecting said member to the cam to cause the member to be shifted first in one direction and then. in the reverse direction r the cam, and means for stoppin the rc ersc movement of said member before it reaches its initial position to cause the cam to be moved axially during the continued rotation of the cam to disconnect the dris-ing mechanism from the shaft.

'18. A driving and stopping mechanism having, in combination a (l1l\ rig clutch member, a driven clutch member, a cam rotated by the driven clutch member and a2;-

ially movable in opposite directions to move the driven clutch member into and out of en gagement with the driving clutchn'iember, a spring for moving the cam axially to engage the clutch members, a member normally disconnected from the cam, means for connecting said member and cam to cause said member to be shifted first in one direction and then in the reverse direction by the cam, and a pawl for stopping the reverse movement of said member before it reaches its initial position to cause the cam to be moved axially during the continued rotation of the cam to disengage the clutch members.

19. A driving and stopping mechanism having, in combination, a criving clutch member, a driven clutch member, a cam rotated by the driven clutch member and axially movable in opposite directions to move the driven clutch member into and out of engagement with the driving clutch member, a spring for moving the cam axially to engage the clutch members, a member normally disconnected from the cam, means for connecting said member and cam to cause said memher to be shifted first in one direction and then in reverse direction by the cam, a pawl for stopping the reverse movement of said member before it reaches its initial position to cause the cam to be moved axially during the continued rotation of the cam to discngagethe clutch members, and treadle controlled means ior actuating the pawl to release said member.

20. A driving and stopping mechanism having, in combination, a driving clutch member, a driven clutch member, a cam rotated by the driven clutch member and axially movable in opposite directions to move the driven. clutch member into and out of engagement with the driving clutch member, a

spring for moving the cam axially to engage the clutch members, amember normally disconnected from thecam, means for connectmg said member and cam to cause sald member to be shifted first in one direction and then in the reverse direction by the cam, a

7 pawl for stopping the reverse movement of comprising a rotatable and axially movable cam acting during its axial movement in one direction to disconnect the drivlng niechanism from the shaft, a locking bolt carrier, a lock bolt on the carrier normally out of engagement with the cam, and means for moving the locking ibolt into engagement with the cam to cause the cam to be moved axially during the continued rotation, of the cam to disconnect the driving mechanism from the shaft. I v

22 A driving and stopping mechanism having, in combination, a driving clutch member, a driven'clutch membena cam rotated by the driven clutch member andaxially movable in opposite directions to move the driven clutch member into and out of engagement with the driving clutch memher, a lock bolt carrier, a locking bolt on the carrier normally out of engagement'with the cam, and means for moving the locking bolt into engagement with the cam to cause the cam to be moved axially during the continued rotation of the cam to disengage the clutch members.

'23. A driving and stopping, mechanism having, in combination, a driving clutch 7 member, a driven clutch member, a cam rotated by the driven clutch member and axially movable in opposite directions to move the driven clutch member into and out of engagement with the driving clutch member, a spring for moving the cam axially to ei'igage the clutch members, a lock bolt carrier, alocking bolt on the carrier normally disconnected from the cam, means for moving the locking bolt into engagement with the cam to cause the lock bolt carrier to be shifted first in one direction and then in the reverse direction by the cam, and a pawl for stopping the reverse move- ,ment of the lock bolt carrier before it reaches its initial position to cause the cam to be moved axially during the continued rotation of the cam to disengage the clutch members.

24. A driving and stopping mechanism having, in combination, a driving clutch member, a driven clutch member, acam. rotated by the drlven clutch member, and

axially movable in opposite directions to move the driven clutch member into and out of engagement with the driving clutch member, a clock bolt carrier, a' locking bolt on the carrier normally out of engage ment with the cam, means for moving the locking bolt into engagement with the cam to cause the cam to bemoved axially during the continued rotation of the cam to disengage the clutch members, and treadle con-. trolled means for withdrawingthe locking. bolt from the cam.

, 25. A driving and stopping mechanism having, in combination, a drlving clutch member, a driven clutchj member, a cam rotated by the driven clutch member and axially movable in opposite directions to move the driven clutch member into and out of engagement with the driving clutch member, a spring for moving the cam axial- .ly to engage the clutch members, a lock bolt carrier, a'locking bolt on the carrier normally disconnected from the cam, means for moving the looking bolt into en gagenient with the 0am to cause the lock bolt carrier to be shifted first in one direction and then in the reverse direction by the can], a pawl for stopping the reverse movement of the lock bolt carrier before reaches its initial position to cause the (321111 to be moved axially during the continued rotation of the cam to disengage the clutch members, and treadle controlled means for Withdrawing the locking bolt from the cam and for actuating the pawl to release the look bolt carrier.

In testimony whereof I have signed my name to this specification.

LAURENCE E. TOPHAM.