US2530974A - Safety handle for controllers - Google Patents

Description

Nov 21 1950 H. c. KRAPF ETAL 2,530,974

SAFETY HANDLE FOR CONTROLLERS Filed Dec. 18, 1947 2 Sheets-Sheet 1 m INVENTOR5 WITNESSES Her/nan C. A rap/ a d l aul A. 1/0 Umer.

ATTOR 1950 H. c. KRAPF ET AL 2,530,974

SAFETY HANDLE FOR CONTROLLERS Filed Dec. 18, 1947 2 Sheets-Sheet 2 WITNESSES: INVENTORS Her/nan 6. Arap/ and l aul L. l/a/knerz Patented Nov. 21, 1950 SAFETY HANDLE FOR. CONTROLLERS Herman C. Krapf and Paul L. Vollmer, Wilkinsburg,. 2a., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa a corporation,

of Pennsylvania ApplioationDecember 18, 1947, Serial No. 192,380

7Claims. 1

Our invention relates generally, to controllers and, rnore,particularly, to safety handles for con- (rollers of .a type suitable forcontrollingthe operatibn, of electric locomotives. v

locomotives, cars, and other equipment nowin service, particularlyinmines, require the addition of safety devices in order to meet the safety requirements setby, industry and government regulations.

object of our invention, generally stated, is toprovide a safety handle. for acontroller which shallbe simple and eiiicient in operation and which be economically manufactured and installed A morespecific object of our inventionis to provide a safety handle which may be readily attached to existing controllers .Another-objectof ourinvention is to provide a controller handle which must be depressed while power is appliedto the motors controlled by. the controller.

' A further object of our invention is to so operate a contactor disposed externally of a controller that circuit interrupting duty is removed from the controller.

Stillanother object of our invention; is to provide a controller handle which must be returned to the .off position and then advanced to reapply;.p0wer. to the motors after a. power failure.

Other objects of our invention will be-explained ful y, e e na e r i be appa ntq os skilled in. the art,

I In accordance with one embodiment. of our in vention, a safety handle} device ispso. constructed;-

that itmay belreadil y attached to the top of an exieting controller, The operating shaft of the. handle is: connected to the. controller shafthye;

15st; motion device which permitsthelhandleto be rotated a suitable number of degrees before the controller shaft is rotated; Cam SWitiCheS diS-r,

posed within the safety, device are: so operated and connected in thecontroller circuits that power is. shutoff if; the operator releases thehandle or moves the handle toward 1 the fofii' Rtisiti Bo r, anno in be, ppl eduntil the, controller is returned tothe .off;1-*- position and then advancedin the vusual manner. 7

For a better understanding of thenature and objects of our invention reference maybe ihad to the following detailed description, taken in conjunction with the, accompanying drawings, in which:

' Figure l isa view, partially-in longitudinalsec tion and partially in elevation, of v a portion of a sntw e x od i uren e ti n B 2 is. a. VEMW, part ailypin.tmnsyersewction and na iallr ian aof: hesaretyh nd-mariachen y rhe ont ol er ,Fig- 3. a s ct o al; ew hr ushthe lost moiq v vice for connect n the operatingshaft and; he c r ler shat- F a, 4f1is1a;dia am showin nartvor the circuit. connections: for; thercontrollerr Referring, to, the drawin s; andunarticularlr to Fi the, tructu eshown; herein comprises :a p rti f a c ntr ller having, azmainsshaft m which; is rota e/J l mcunteda n a. hearing 1:. disposed inthe-top of a asinszl-l. The mainsraft ID, is. cqnnectedz to-,.a coazgigally disposed operating Sha t, 3: l-through a, lostlmo ionv device I14 The operating-shaft I 3 3 is 1 mtatablyxmounted in; bearinss 5am; 6.:Which; are. disnosedin the top H andth bottom; l; -Lr;eSpfic iY:1y-. of.-asafety: handle device, lflrwhich maybe. mountedlon top of, the co troll r: casin l2.-

The safety device I19, may beu attached to the controller b means. vofxhn adapter plate-2 lr-Which may be riveted or b lted- .to thev toplof, the com troller casing; 12. The b,0t13Qm;,-|8i'0f; theasafety device I 9, maybe bolted to hthe'adapter, plate r2] by means f. boltsqll The safety i device I 9 ishrovided with a, handle 23 which isqvpivotallytmounted, inuarbracketzx which may be securedei o the .operatingshaft;l3. bysetscrfiws 25., Thehandlesz ,3;:may.be actuated na vertical. plane-a wellasina horizontal plane,

as.- will Joev explained more, fully vhereinafter.

.Thelost; motion device lliwhichhconnects the. two shafts lll andi l3 comprises =a sleeve 25::which 1 is secured to the shaft l3.; andc.a.collar 21:.which isasQQ tel tozthe Shaftzlfl. The; sleeve KZBEhasHa r ove sl 285cm:thereinand-the collar 2? is proyided; with al srib ;2 9 which is. disposed in. the SlOfigZQgflSgShOWXI; in, Fig.5 3. The; slot128'ris so. ma-l chinedihatzthe: sleeve 25.10am rotate a pre-deter minedezamountibeforeathe side of :the-slot AB-engages the-rib 9.-

As shown in Figs. 1 and 2, two cam switches 34 'and-3'2-are-s0 mounted in-the safety device [9 that they maybe actuated by cams 33and'34; re-

spectively. The cam "is attached to a flanged collar'35 by screws 3 jand the collar..35"is..secured' on,the shaft"l 3 vbyla pin 3]. "Therefore, the cam H rotates with the. shaft 1 3..

retr ta abl m untedtoni he.. haf l3! he-C0 ,larsi ll and. 42 are separateti -by;aspiring til-amide a spring 44 which is mounted inside of the spring 43.

The initial pressure of the spring 44 is set by screws 45 which engage a washer 46 disposed on top of the spring 44. The pressure of the spring 43 is increased by actuating the handle 23 in a vertical plane which transmits force to the collar 4| by depressing a plunger 41 to cause a key 38 which is disposed in a slot 49 to engage the collar All and lower the collar against the spring 43. As the collar 4| is lowered, it engages the washer 46 to increase the pressure of the spring 44.

In this manner the cam 33 is gripped between the collars 42 and 35 and is rotated by the collar 35 against the compression of a spring 5|. As shown in Fig. 2, one end of the spring 3| is connected to the cam 33 and the other end is adjustably connected to the housing of the safety device l9.

As also shown in Fig. 2, the rotation of the cam 33 is limited by a stop pin 52 which is mounted on one side of the housing of the safety device |9 and is disposed in a slot 53 in the cam 33. After the cam 33 has been rotated to the limit of its travel permitted by the stop pin 52, it remains in this position so long as the handle 23 is depressed and rotated in the same direction. When the cam 33 has reached the limit of its travel,

the friction clutch 38 slips thereby permitting the handle to be rotated further.

Assuming that the handle 23 is rotated in a clockwise direction from the off position to apply power to the motors controlled by the controller, pressure is applied to the cam 33 in the manner hereinbefore described by depressing the handle 23. When the handle is rotated in a clockwise direction, the cam 33 is rotated a predetermined amount, for example 15, against the spring 5| until further rotation of the cam is stopped by the stop pin 52. t the end of the 15 rotation of the cam 33, the contact members of the cam switch 3| are closed.

As explained hereinbefore, the lost motion device M which connects the operating shaft l3 to the main shaft l9 has a predetermined amount of lost motion, for example, 15. Thus, the main controller shaft [6 is not rotated until after the end of the 15 motion is reached.

As shown in Fig, 2, a notch 5-4 is provided in the cam 36. The notch 53 is so located that as the main controller shaft H is rotated into the first operating position of the controller, the contact members of the cam switch 32 are closed.

As shown in the diagram in Fig. 4, when the cam switches 3| and 32 are both closed, the actuating coil of a line switch 55 is energized, thereby closing the line switch and applying power to the motors (not shown) through contact members 56 of the line switch. Auxiliary contact members 51 on the line switch 55 are also closed at this time to bridge the contact members of the cam switch 32.

Further rotation of the handle 23 operates the controller to shunt resistance from the motor circuit in the usual manner. When the controller is rotated past the first operating position, the cam switch 32 is opened by the cam 34. However, the energizing circuit for the actuating coil of the line switch 55 is maintained through the auxiliary contact members 51.

If the line switch is opened for any reason, as, for example, by operation of an overload protective device, it cannot be reclosed until the controller is returned to the off position and then actuated to the first operating position in the regular manner to reclose the cam switches 32 and 3|. Therefore, the power cannot be reapplied to the motors without the full amount of the resistance being inserted in the motor circuit.

If the operator releases the handle 23 with the controller in any operating position, the pressure of the friction clutch 38 on the cam 33 is released and the spring 5| rotates the cam 33 in the counterclockwise direction 15 to open the contact members of the cam switch 3| which opens the circuit for the actuating coil of the line switch 55, thereby opening the line switch and cutting off power from the motors.

If the handle 23 is moved from any operating position toward the off position, the first 15 of motion opens the cam switch 3| which, in turn, causes the line switch 55 to open. The 15 of counterclockwise motion which opens the cam switch 3| must be completed before the controller drum is rotated counterclockwise because of the lost motion device l4 between the controller shaft and the operating shaft |3. In this manner, the motor circuit is always opened by the line switch 55, thereby preventing the contact members of the controller from opening the motor circuit.

In order to close the circuit for the actuating coil of the line switch 55, the 15 of lost motion must first be taken up and then the controller rotated to the first operating position to close the line switch 55 in the manner hereinbefore expiained. This necessitates that the handle 23 be returned to the off position, depressed and then rotated in the manner hereinbefore described.

From the foregoing description it will be seen that the safety handle device functions to cause power to be shut off if the operator releases the handle. Power is also shut off when the handle is moved from any operating position toward the off position and power cannot again be applied until the controller is rotated to the off position and notched up in the regular manner.

Thus, the device requires that the operator keep his hand on the operating handle while power is applied to the motor. The device so controls the operation of a line switch that circuit interrupting duty is removed from the controller, thereby reducing the possibility of flashover and reducing controller maintenance.

Furthermore, the device requires that the controller be returned to the off position and notched up in the regular manner in case of a power failure of any kind, thereby preventing the motor from being started unless the full amount of starting resistance is in the motor circuit. This reduces the possibility of the motor flashing and prevents the equipment from starting with sudden jerks which might throw the operator from his seat.

Since numerous changes may be made in the above-described construction, and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

We claim as our invention:

1. In a controller, in combination, a main shaft, an operating shaft disposed coaxially with the main shaft, a handle pivotally mounted on the operating shaft and movable in a vertical plane and in a horizontal plane, a lost motion device for connecting the operating shaft to the main shaft, a friction clutch actuated by movement of the handle in a vertical plane, a cam driven by the operating shaft through the friction clutch, switching means actuated by said cam prior to rotation of the main shaft by the handle through the lost motion device, an additional cam secured to the operating shaft, and additional switching means actuated by said additional cam independently of the friction clutch.

2. In a controller, in combination, a main shaft, an operating shaft disposed coaxially with the main shaft, a handle pivotally mounted on the operating shaft and movable in a vertical plane and in a horizontal plane, a lost motion device for connecting the operating shaft to the main shaft, a friction clutch actuated by movement of the handle in a vertical plane, a cam driven by the operating shaft through the friction clutch, switching means actuated by said cam means prior to rotation of the main shaft by the handle through the lost motion device, an additional cam secured to the operating shaft, and additional switching means actuated by said additional cam after rotation of the main shaft by the handle through the lost motion device.

3. In a controller, in combination, a main shaft, an operating shaft disposed coaxially with the main shaft, a handle pivotally mounted on the operating shaft and movable in a vertical plane and in a horizontal plane, a lost motion device for connecting the operating shaft to the main shaft, a friction clutch actuated by movement of the handle in a vertical plane, a cam rotated by the operating shaft through the friction clutch, switching means actuated by said cam, an additional cam rotated by the operating shaft independently of the friction clutch, and additional switching means actuated by said additional cam.

4. In a controller, in combination, a main shaft, an operating shaft disposed coaxially with the main shaft, a handle pivotally mounted on the operating shaft and movable in a vertical plane and in a horizontal plane, a lost motion device for connecting the operating shaft to the main shaft, a friction clutch actuated by movement of the handle in a vertical plane, a cam rotated by the operating shaft through the friction clutch, switching means actuated by said cam prior to rotation of the main shaft by the operating shaft through the lost motion device, an additional cam rotated by the operating shaft independently of the friction clutch, and additional switching means actuated by said additional cam.

5. In a controller, in combination, a main shaft, an operating shaft disposed coaxially with the main shaft, a handle pivotally mounted on the operating shaft and movable in a vertical plane and in a horizontal plane, a lost motion device for connecting the operating shaft to the main shaft, a friction clutch actuated by movement of the handle in a vertical plane, a cam rotated by the operating shaft through the friction clutch, stop means for limiting the rotation of the cam, switching means actuated by said cam, an additional cam rotated by the operating shaft independently of the friction clutch, and additional switching means actuated by said additional cam.

6. In a controller, in combination, a main shaft, an operating shaft disposed coaxially with the main shaft, a handle pivotally mounted on the operating shaft and movable in a vertical plane and in a horizontal plane, a lost motion device for connecting the operating shaft to the main shaft, a friction clutch actuated by movement of the handle in a vertical plane, a cam rotated by the operating shaft through the friction clutch, stop means for limiting the rotation of the cam, switching means actuated by said cam, and spring means for rotating said cam to open said switching means when the friction clutch is released, an additional cam rotated by the operating shaft independently of the friction clutch, and additional switching means actuated by said additional cam.

7. In a controller, in combination, a main shaft, an operating shaft disposed coaxially with the main shaft, a handle pivotally mounted on the operating shaft and movable in a vertical plane and in a horizontal plane, a lost motion device for connecting the operating shaft to the main shaft, a friction clutch actuated by movement of the handle in a vertical plane, a cam rotated by the operating shaft through the friction clutch, switching means actuated by said cam, an additional cam secured to the operating shaft, and additional switching means actuated by said additional cam independently of the friction clutch.

HERMAN C. KRAPF'. PAUL L. VOLLMER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 731,375 Liggett June 16, 1903 1,247,911 Walkup Nov. 27, 1917 1,497,827 Acker June 17, 1924 1,806,377 Whittingham May 19, 1931 2,198,469 Woodward Apr. 23, 1940 FOREIGN PATENTS Number Country Date 538,254 Great Britain July 25, 1941

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