US1658036A

US1658036A - Make and break switch for adding machines

Info

Publication number: US1658036A
Application number: US741525A
Authority: US
Inventors: Theodore S Bindschedler
Original assignee: BURROUGHE ADDING MACHINE CO
Current assignee: BURROUGHE ADDING MACHINE Co
Priority date: 1924-10-04
Filing date: 1924-10-04
Publication date: 1928-02-07
Anticipated expiration: 1945-02-07

Description

Feb. 7,. 1928.

T. S. BIN DSCHEDLER MAKE AND BREAK SWITCH FOR ADDING MACHINES 3 Sheets-Sheet 1 12v VEN TOR ATT T. s. BINDSCHEDLER MAKE AND BREAK SWITCH FOR -ADDING MACHINES Feb. 7, 1928. 1,658,036

Filed 00?..4. 1924 s Sheets-Sheet 2 [0/ 1N VENTO Feb. 7, 1928.

1,658,036 T. S. BINDSCHEDLER/ MAKE AND BREAK SWITCH FOR ADDING MACHINES Filed 0ct.4. 1924 3 Sheets-Sheet 3 IVENTOR' v ATTORN E? 1'0 fected byl Patented Feb. 7, 1928.

- UNITED STATES PATENT OFFICE- THEODORE S. IBINDSCHEDLER, OF DETROIT, MIG HIGAN, ASSIGNOR TO BUBBOUGEB ADDING- CO., 01 DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN;

ELIE ANDBREAiK SWITCH FOB ADDING MACHINES.

Application filed October 4,

This invention relatesto power-driven machines and its purpose is to provide proved means for controlling the connections ofthe machines with the. source of 6 power. In an adding machine of the Bur.- roughs type, for example, the first half or forward stroke of each operation of the machine is eifected by a motor and the last half or return stroke of the operation is efs rings in which energy is stored during t e orward stroke, the connection of the motor'with the operatin mechanism of .the machine being made and broken at the beginning and ending, respectively, of the.

operation by means of a clutch, but in such machines, as constructed prior to the present invention, the driving motor remains in operation throughout-the series or succession of operations of the adding machine. The principal object of the resent invention is to provide means where y the operation of the driving motor is rendered intermittent, the connection of themotor with the source of power being made and broken intermittently so that the motor idles and comes to rest during each return stroke of the machine operation. A A further object of the invention isto provide means whereby the motor circuit is closed and the motor started in operation by the. depression of the finger; bar which is manipulated by the operator in starting the operation of the machine. A feature of the invention is the provision of means whereby a complete operation of the clutch mechanism is insured even when the manipulation of the finger bar by the operator is incomplete or faulty. Still another object is to provide means whereby the connection ofthe motor with the source of power is made simultaneously with the operation of the clutch by which the connection of the motor with the operating mechanism of the adding machine is controlled. The invention is capable of being employed with particular advantage in connection with series wound electric motors of the universal type, since the automatic circuit control prevents the motor from acquiring excessive speed and the armature thereof slows up or comes to rest after each forward stroke of the adding machine mechanism. 7

Still another object of the invention is to rovide an improved make and break switch or controlling the circuit ofan electric .1924. Serial No. 741,595.

motor. A particular advantage of the improved switchlies in the provision of means or obtaining apositive contact and for effecting a relative movement of the contact ing parts so that dirt and sediment are removed therefrom when the switch is operated. A further feature is the provision of an improved switch-comprising means for efi'ecting a quick or instantaneous action of the means by which the movable contacts are actuated.

Although the present invention is capable of application to various power-driven mw chines, it has been illustrated in connection with an adding machine of the type disclosed in the United States atent to J. G. Vincent, No. 866,750, granted September 24, 1907, to which reference is made for a more complete disclosure of the adding machine. The various objects and advantages of the present invention will a pear more full from the following speci cation taken wit the accompanying drawings in which Fi 1 is a side elevation of so much of an adding machine proper as is necessary to an understanding of the present invention, parts thereof being broken away to illustrate the construction more clearly. Fig. 2 shows an enlarged side elevation of a portion of the machine, including the controlling .mechanism, showing the position of the parts at the. moment of closing the electric swltch for starting .the motor; Fig. 3 shows a partial side elevation similar to Fig. 2, illustrat ing the sitions of the parts at the moment of opening the switch ,and breaking the 011'- cuit of the motor. Fig. 4 is an elevation of the driving mechanism shown in Fig. 1, the view being taken at right an Ice to that of v Fig. 1, anda portion thereo being shown in section on the lines 1-4 of Fig. 1; Fig. 5 is a section on the line 55 of Fig. 2, showing the mounting of the control lever and the switch lever illustrated in Figs. 1, 2 and 3; Fig. 6 is a perspective view showing various parts which make up the yielding'contact portion of the switch, and Fig. 7 is a sectional view taken on the line 77 of Fig. 4, showing the means for controlling the operation of the clutch by which the motor is connected to the operating mechanism ofthe adding machine.

As illustrated in the accompanying drawings, the adding machine is shown as one of the well known Burroughs type, for a more complete disclosure of which reference may be hadto-the above mentioned Vincentpatent-and the United States Patents Nos. 504,- 963 and- 505,078, granted to W. s. Burroughs, on June 12, 1893. The machine comprises a frame having mounted thereon an electric motor 11 which may preferably be a series wound electric motor of the U111- versal type having a relatively low inertia and a high acceleration. The armature of the motor is mounted on or connected to a shaft 12 which extends into andis journaled in the walls of the clutchvhousing 13, as

shown particularly in Fig. 4. A worm 14 is fixed on the shaft 12 and meshes with a worm wheel 15 rotatably mounted on a shaft 16 which is journaled in suitable bearings in the walls of the housing and which has fixed on the projecting end thereof a crank arm .17 pivotally' connected by a .pin 18 with a link or connecting rod 19 which isin turn pivot ally connected with a crank arm 20 fixed on the rock shaft 21 of the adding machine. The worm wheel 15 is adapted to be connected to the shaft 16 in order to efi'ect the operation of the rock shaft 21 by the motor, through the operation of a clutch comprismg an annulus 25 secured to the side of the worm wheel 15 concentrically with the shaft 16. The outer periphery of the annulus 25' is provided with a series of semi-cylindrical recesses 26 any one of which may be engaged by a clutch pin 27, of semi-clrcular cross section, which has the cylindrical end \portion thereof rotatably mounted in a clutch disc 28 having an annular flange 29 surroundmg the annulus 25. The disc 28- has its hub secured to the shaft 16 by means of a pin 30 nulus 25. The clutch operating lever 31 is provided with arms 31 extending downwardly at each side of the segniental gear 35 to limitthe movement of the lever and a plate 37 extending between these armsserves to maintain the clutch pin 27 in its bearing in the clutch disc 28. The upper end of the operating lever 31 is normally moved toward the left as viewed-in Fig. 7 by means of a coil spring 40 which is connected at' one end to the lever and at the other end to .a pin attached to the clutch disc. The extremity 42 of the lever 31 is provided with a curved surface 43 adapted to coact with a" detent 44 of semi-circular cross section which is secured to one end of a pin or shaft 45 jour- When the curved surface of the detent contacts with the curved surface 43 of the operating l'ever', the lever is held in the position illustrated in Fi 7 against the tension of the spring 40 an the clutch pin 27 is then out of. engagement with any of the notches 26, but when the shaft 45 is rotated to permit the'endof the lever 31 .to pass .beneath the flat face of the detent 44, the lever 31 moves toward the left, as viewed in Fig. 7, under the influence of the s ring 40, thereby rotating the clutch pin 27 engagement with one of the notches 26 in the annulus 25. e 4

The shaft 45015 the detent 44 is actuated to control the clutch by certain mechanism comprising a segmental'gear 46 secured to the shaft 45 and arranged to mesh. with another segmental gear 47 mounted on a pin 48 secured to the cover 13 of the clutch housing. The segmental gear 47 is formed on or and bringing it into 7 .secured to the hub of an arm or lever 50, the V outer end of which carries an eye-bolt 51 slida'bly engaged by a rod 52, the lower threaded extremityof which is engaged by nuts 53 while the lower reduced portion thereof is surrounded by coil spring 54 contacting at one. end with the eye-bolt 51 and at the other end with the shoulder 55 on the rod. The rod52 is adapted to be elevated by the manual operating of the finger bar 57 which is manipulated by the operator at the commencement of each operation of the adding machine. The finger bar 57 is connected by members 58 with the extremities of

levers

59 and 60 which are pivoted at the points 61 and connected by a coil spring 62 so that they normally tend to maintain the finger bar 57 in its uppermost position. I The

levers

59 and 60 have a loose pin and slot connection at 63 and the lever 60 is provided with an extension 60 carrying a pin 63 which engages a slot 64 in the upper end of the rod 52. A coil spring 65 connects the extension 60 of the lever with the rod 52 at a point below the slot 64. It will be apparent that the depression of the finger bar 57 operates to elevate the bar 52 and thereby rock the arm 50 through which the detent 44 is actuated. The rod 52 is provided with a lateral extension 52 having av shoulder 66 adapted to be engaged by a roller 67 mounted on the sector 68 which moves downwardly duringthe forward stroke or first half of the operationof the machine, the engagement of the roller with-the shoulder 66 being utilized to restore the member 52 to its normal position, and thereby operate the lever 50 to effect a disengagement of the clutch, due to the ac{ tion of the detent 44 in obstructing its lever 31 and thereby causing angular movement of the clutch pin, as hereinafter more fully described.

sill

neuaoee trols the engagement and disengagement of the clutch, serves also to control the closing of the switch by which the motor is connected to its supply circuit. This control is effected by a roller 70 which. is mounted on the lever and adapted to coact with the head 71 of an inverted T-shaped switch control lever 71 pivotally mounted on astud '72fsecured in the cover 13 of the clutch housing. The lever 71 has two oppositely directed arms 71 and T1 at the lower end thereof and the head 71 is provided with a fiat end face 71 and a curved cam surface 71 these

surfaces

71 and 71 being adapted to coact with the roller for controlling the movement of the lever T1 and tor insuring a complete movement ot' the lever 50 after it has been actuated by the depression of the linger bar 5].- ji-coil spring 73 is connected to the arm 71" ot'the lever and to a pin 74 secured to the clutch casing, this spring serving normally to move the lever 71 toward the left as viewed in Figs. 1 2 and 3, the limit otthis movement being determined by a stationary pin or ahutn'ient 7% which is secured to the cover of the clutch casing The outer end 0'' the arm 71 of the lever also carries a stud 75 having pivotally mounted thereon a yolre-shaped pawl T0 provided with a l-shaped head '16 having anupper inclii :irtac-e To and a lower inclined surface To The pawl T6 is connected by a coil spring Tl with the body portion of the lever 71 so that the pawl is normally moved toward the rigid. as viewed Figs. 1, 2 and 8, thereby tending to maintain one or the other 01"" the inclined suit-races ot the pawl in contact with a roller T8 mounted on a pin attached to'the arm 1 9 of the switch lever 79 which is pivotally mounted on the stud '12 at one side otthe sw ch control lever 71. The other arm 71 the lever T1 is provided at its outer ends with a roller'SO which is adapted to coact with the periphery of a snail cam 81 secured to the end ot the clutch shaft 16 and adapted to control the opening of the electric switch. as hereinafter described. The upwardly extending arm 79 of the switch lever 79 carries the movable switch contacts 83 and 8 1 whichare adapted to coact with the stationary contacts 85 and 86, respectively, when the switch lever is operated to close the switch. lhc stationary contacts 85 and 86 are carried hy l..-shaped plates 8'? and 88. respectively, which are secured to an insulating plate 89 and connected with binding posts 91 and 9'2, respectively, secured in position in the insulating; plate. An insulated cable 93 leading from a'source of supply of electrical energy. earries a pair of line conductors, one conductor 94 being connected to the binding post 92, while the other conductor-95 is connected to a binding post 96 connected to and insulated from the casing 13 of the clutch housin Another insulated cable 97, carries a pair of completed between the conductor 94 and the conductor 98 so that the circuit of the motor is then closed, the other side of the supply circuitbeing completed between the conductors 95 and 99 through the common binding post 96.

The parts by which the movable contacts 83 and 8 1 of the switch are connected are erably so constructed that the contacs relative movement when they engage the s tionary contacts 85 and 86, thereby remo carbon and other deposits from the stu of the contacts and insuring perfectnection. For this purpose the contact 83 is mounted on a transverse flange 100 of a plate 100 and the contact 8 1 is mounted o" transverse flange 101 of a plate 10' plates being pivotally supported on or sulating bushing 102 which is secured on pin 103 projecting laterally from the upper end of the switch lever 79, as shown particularly in Fig. 6. The hashing 10:2 endie apertures 105 which are torme the plates 100 and 101 and the plates maint 'ned out of contact with the lever V insulating washer 1' The pl 5 secured l position against the we. in contact with each other "y me a; ring plate 107 which is sect switch ever 'l9 by a rivet 1 provided at its upper end v 109 adapted to fit ove the I bushing 102 in contact with anot lating washer 106 The projecting rms 0 the plates 100 and 101 which ca flanges 100 and 101, respectivelvi, are connected by a coil spring 110 which tends normally to move the contacts 83 i 81- d in gaged by anir .lating bushing 11% mounted on a pin projecting laterally from the lever 7 9. ll l'ien the switch contacts 83 and 8e are brought into engagement with the stationary contacts 85 and 86, respectively, the contacts 83 and 8t spread apartslightly against the tension of the spring- 110 with the result that a wiping contact is obtained. The movement of the switch lever 79 away from the stationary contacts 85 and 86 is limited by a lug 117 formed on the lever and adapted to engage the stop pin 74 by which the movement of the control lever 71 is limited.

In the operation of the adding machine, after the number to be entered has been set up in the keys, the finger bar 57 is depressed, thereby elevating the rod 52 and producing an upward movement of the crank or lever 50 from the normal position shown in Fig. 1, which throws the clutch detent 44 in such a position that the end of the clutch control lever 31 is permitted to pass beneath the fiat face of the detent under the influence of the spring 40. This movement of the clutch control lever 31 rotates the clutch pin 27 into engagementwith one of the notches 26 in the annulus 25, thereby forming a driving connection between the motor driven worm wheel 15 and the shaft 16 by which the rock shaft 21 of the adding machine is operated. The initial upward movement of the lever 50 carries the roller 70 out of engagement with the flat end face 71 of the lever 71 and into engagement with the curved surface 71 of the lever so that the lever is then free to move toward the left, as viewed in Figs. 1, 2 and 3, under the influence of the coil spring 73. This movement of the lever 71 insures a complete upward movement of the lever due to the engagement of the inclined cam surface 71 with the roller 70 and it also brings about the closing of the switch simultaneously with the engagement of the clutch, the closing of the switch being caused by the downward movement of the arm 71 of the switch control lever which carries with it the pawl 76 until the apex of the head 7 6 of the pawl rides past the roller 78 and the roller 78 contacts with the upper inclined surface 76 of the pawl, as shown in Fig. 2,.whereupon the inclinedsurface 76 forces the lever 79 upwardly and inwardly, under the influence of,the spring 77, until the switch contacts 83 and 84 engage and form a wiping contact with the stationary contacts 85 and 86. The switch remains closed during the forward stroke or first half of the cycle of operation of the adding machine proper, during which time the rock shaft 21 is operated by the power of the motor and energy is stored up in the coil spring 120 by which the subsequent return stroke of the addingmachine mechanism is effected. During. the forward stroke, the snail cam 81, mounted ;on the shaft 16, rotates in a counterclockwise direction until at the end of the forward stroke, the projection of the cam forces the roller 80 on the control lever 71 downwardly to such an extent that the apex of the V-shaped head 76 ofthe pawl 76 is carried upwardly over,

the roller 78, whereupon the lower inclined surface 76 of the pawl operates to force the switch lever 79 toward the left, as viewed in Figs. 1, 2 and 3, thereby snapping the switch into open position. This position of the parts of the switch is illustrated in Fig. 3 where the switch is shown in open position and the lever 50 is shown approaching the normal position illustrated in Fig. 1. The return of the lever 50 to its normal position with the roller engaging the end face 71 of the lever 71 is brought about by the down-' ward movement of the sector 68 of the adding machine which moves the roller 67 into engagement with the shoulder 66 on the elevated rod 52 which moves the rod downwardly and creates a compression in the spring 54 so that the lever 50 is in readiness to return to its normal position under the influence of the spring 54 as soon as the head 71 of the switch control lever has moved toward the right, as' Viewed in Fig. 3, to a suflicient extent by the snail cam 81 during the forward stroke of the adding machine. The parts are so constructed and arranged that the downward -movement of the rod 52 returns lever 50 to the normal position shown in Fig. 1, during the forward stroke, so that the detent 44 is turned,

into a position to obstruct the end of the rotation at the end of the return stroke, the

detent 44 engages the curved surface 43 on the end of the lever 31 and produces a movement of this lever on its bearing sufficient to disengage the clutch pin 27 from its notch 26. Thus the electric power is cut off simultaneously with the ending of the forward stroke and the armature of the motor is permitted to idle and come to rest during the return stroke of the adding machine mechanism which is effected by the spring 120. In this way the operation of the electric or other driving motor is rendered intermittent and the connection of the motor circuit is made in synchronism with the engagement of the clutch.

This improvement is of advantage in connection with any power driven adding machine or other machine but it is particularly advantageous where an electric motor of the Universal type is employed, particularly a series wound motor. W1th a motor of this type the speed which may be obtained is ordinarily variable and uncertain and may rise to unsafe limits if the power remains connected to the motor after the load is removed, and since the speed with which the adding machine may be successfully operated is limited, the present invention achieves the important result of preventing an undue speed of-the motor by; reason of the fact that the motor circuit is intermec nism even when the linger bar 7 been shown and rupted intermittently and the armature brought to rest, or reduced greatly in its speed during the no-load condition of the return stroke, between successive operations or the finger-bar. In the cycle of operations of the adding machine, the forward stroke during which the machine in driven by the motor and energy is stored up in the spring 120, constitutes a working cycle while the return stroke of the machine which is efiected by the energy stored up in the spring may be termed a no-load cycle since no power is then taken from the source of electric energy and motor is disconnected. The disconnection of the motor not only prevents it from acquiring undue speed under the no-load condition but also efiects a saving or the power required to operate a motor without load. -ne invention not only serves to operate e electric switch simultaneously with the o eration of the clutch, thcreby preventing damage to the machine, but it also in ures complete operation of the clutch control ctly or incompletely manipula ht depression or the finger bar is Suficient to raise the roller "l0 out of engagement the end face 71 of the switch control and, thereafter, a complete u ward movement of the lever 50 is b ought about the inclined surface 71 on. the lever so ,L'l

th t e detent e; is moved to the 'oper exam" to release the lever 31 a proper engagenie t or the cl ore the :3 1115 are set in motion by the driving motor; The construction duces raoid eration of the switch mechanism a: d snitch control mechanism the contact of the switch contact of relatively oroduce a mo." feet circuit connecti n than can be obtained with swi" of the type heretofore know Although one term oi. the invention has described by way of illustration, it will be und rstood may be c structed in various other embodiments out departing from the scope of the ap pended daims.

combination, machine, a motor for ClVlllg said machine, means for forming a said machine, means actuated by a common control said named means for connecting said motor with a source of ower, means for disconnecting said motor from d source of power while permitting said connection to be maintained.

in combination, a machine, an electric motor for driving said machine, a clutch for L'Iorming a driving connection between said motor and said machine, a switch connecting said motor with a source oi power, means havinga common control for simultaneously said mac 2 ng connection between said motor and operating said clutch and closing said switch, and means for permitting said lest named means to be operated thereafter for opening said switch while continuing the engagement of said clutch.

3. in combination, a machine having a working cycle and a no-load cycle, a motor for driving said machine, a switch o connecting said motor with a source power, and means for disconnecting said motor 1:5 ing said no-load cycle.

s. En combination, a machine having cycle of operations including worlrin period and a no-load period, a series woun electric motor for driving said chine, source of electrical energy connected to said motor, and means for automatically disconnecting said motor from said source during the no-load period of each cycle operations. i

5. in combination, a machi cycle of operations includ' period and a no-load period, s electric motor -iordriving said clutch for forming a driving co tween said otor and mac said motor wit tor closing said clutch at the cried, and me 95 r forming drivin i motor said ma said motor u ane "for simultaneo o closing se sch of said we automatically 0? of each of (I) in} periods. 7 I T combination, driving said machine, a clu a driving connection between said V -e, ch; 11 operating mechanism, a

nipulative member for act ing said clinch operating mechanism, a means by the initial iovement said manually manipulative member ror insuring a complete operation said clutch operatin in cnsnism.

8. combination, a machine having a definite working period oro eration, an electric motor for driving said machine, a clutch for forming driving connection between said motor and said machine, a switch for connecting said motor with a source of power, means having a common control for closing said switch and engaging said clutch, and means operative automatically at the end of saidperiod or operation for opening 1% said clutch and closing said switch while emitting the continued engagement of said clutch.

9. In combination, a machine, a motor for driving said machine, a clutch for connecting said motor with said machine, a switch for connecting said motor with a source of power, means including a manually manipulative member for actuating said clutch, means actuated by said manually manipulative member for effecting the closing of said switch, and means actuated after a redetermi-ned operation of said machine or automatically opening said switch.

10. In combination, a machine, a motor for driving said machine, a clutch for connecting said motor with said machine, a switch for connecting said motor with a source of power, means including a manually manipulative member for actuating said clutch, means actuated by said manually manipulative member for effecting the closing of said switch, and means actuated by said switch closing means for insuring a. complete operation of said clutch actuating means.-

11. The combination with a machine having a cycle of operations including a working period and a no-load period, of a motor for driving said machine, a clutch for connecting said motor to said machine, a clutch for connecting said motor to a source of power, means for simultaneously actuating said switch at the beginning of said worklng period, means for opening said switch at the end of said working period, and means for disengaging said clutch at the end of said cycle of operations.

12. The combination with an adding machine, of a motor for driving said machine, a clutch for connecting said motor to said machine, a clutch operating member, a detent normally restraining movement of said member, means for actuating said detent, a manually manipulative member for operating said detent actuating means, and means actuated by the initial movement of said manuall manipulative member for insuring a comp ete actuation of said detent actuating means independently of said manually manipulative member.

13. The combination with an adding machine, of a motor for driving said machine, a switch for connecting said motor with a. source of power, a clutch for connecti said motor to said machine, clutch operatlng mechanism, means including a manually manipulative member for actuating said clutch operating mechanism, means actuated by the initial movement of said manually manipulative member for insuring a complete operation of said clutch operating mechanism, and means actuated by said last named means for closing said switch.

14. The combination with an adding machine, of a .motor for driving said machine, a clutch for connecting said motor to.

for actuating said switch lever, and means for operating said controlling lever.

16. In apparatus of the class described, a controlling lever, a switch lever, contacts actuated by said switch lever, means carried by said controlling lever for actuating said switch lever, manually controlled means forefl'ectin'g actuation of said controlling lever in one direction to produce a closing movement of said switch lever, and means actuated by the operation of said apparatus for producing a movement of said controlling lever in the other direction to eflect an opening movement of said switch lever.

17 The combination with a machine of the class described, of a controlling lever having relatively inclined cam faces, a spring tending to move said lever in one direction, 7

an actuating lever having a part adapted to co-act with said cam faces, and a switch actuated by said controlling lever, said part of said actuating lever being adapted normally to engage one of said cam faces to hold said controlling lever in a restrained position against the tension of said spring, said actuating lever being adapted by the mitial movement thereof to bring said ,part into engagement with the other of said cam faces and thereb permit a switch closing movement of sald lever under the action of said spring.

18. The combination with a machine of the class described, of a controlling lever, a switch lever mounted adjacent said controlling lever, a roller mounted on said switch lever, a detent having divergent inclined faces each adapted to co-act with said roller, switch contacts controlled by said switch lever, manually operated means for actuating said controlling lever to effect a contact closing movement'of said switch lever b the engagement with said roller of one of s inclined faces, and means actuated by said machine for effecting a reverse movement of said controlling lever and the engagement of said roller with the other of said inclined faces for effecting a contact opening movement of said switch lever.

19. The combination in'a machine of the class described, of a controlling lever, a

aid

switch lever mounted adjacent said controlling lever, a pawl mounted on said controlling lever and having a pair of divergent to move said controlling lever in one direction, a manually releasable member acting normally to restrain said controlling 1ever from movement in said' direction, switch contacts moved into circuit closing position of said manually releasable member, and means for effecting a reverse movement 'of said controlling lever to disconnect said contacts by the movement of said switch lever through the action thereon of the other of said cam faces.

20. The combinatiorr in a machine of the class described, of a controlling lever, a

- switch lever mounted adjacent sald'controlling lever, a pawl mounted on said controlling lever and having a pair of divergent cam faces adapted'to co-act with a part of said switch lever, a spring tending normally to move said controlling lever in one direction, switch contacts moved into circuitclosing position by said switch lever through the operation of one of said cam surfaces ,upon actuation of said manually-releasable member, a rotatable cam driven by said machine, and means carried by said controlling lever co-acting with said cam for effecting a reverse movement of said controlling lever and an opening movement of said switch contacts through the action on said switch lever on the other of said cam faces.

21. The combination in a machine of the class described, of a controlling lever having a laterally projecting arm, a pawl pivotally mounted on said arm and having a pair of divergent cam faces, a spring tending to move said pawl inwardly towards said lever, a switch lever having a part adapted to coact with said cam faces, means for effecting relative movement of said controlling lever to bring one or the other of said cam faces into engagement with said switch lever, and Twitch contacts controlled by said switch ever.

22, The combination in a machine of the clam described, of a controlling lever having a laterally projecting arm, a pawl pivotally mounted on said arm and having a air of divergent cam faces, a spring tending to move said pawl inwardly towards said lever, a switch lever having a part adapted to coact with said cam faces, means for effecting relative movement of said controlling lever to bringone or the other of said cam faces into engagement with said switch lever, a pair of switch contacts mounted on said switch lever and having a limited relative movement, and a pair of stationary contacts adapted to be engaged by said movable contacts.

THEoDoRE s. BINDSCHEDLER.