US1157821A - System of control. - Google Patents

Description

N. W. STORER & A. J. HALL.

SYSTEM OF CONTROL.

APPLICATION FILED MAR. 18. 1914.

1,157,821 Patented Oct. 26, 1915.

Fab/d 600/7: orer and UNITED STATES PATENT OFFICE.

NORMAN W. STORER, OF PITTSBURGH, AND ARTHUR J. HALL, OF WILKINSBURG, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SYSTEM OF CONTROL.

Specification of Letters Patent.

Patented Oct. 26, 1915.

Application filed March 18, 1914. Serial No. 825,491.

' of its objects to combine certain hitherto separately operated members in one piece of control apparatus and to provide means for actuating the same.

Another object of our invention is to provide a control system embodying means of the above-entitled character, whereby the cost of construction and installation and the number of control apparatus members are reduced, and the operation of the system is rendered more economical and convenient than heretofore.

Another object of our invention is to provide a suitable device for electro-pneumatically controlling the operation of a certain control apparatus, as hereinafter described.

Heretofore, the switching devices known in the art-as the reverser and the fieldchange-over switch have commonly been constructed as separate members. As the respective names imply, the reverser is employed to reverse the connections of either the motor armature or the field winding, usually the latter; and the field change-over switch is utilized to change from full field to normal field connections, and vice versa, for a Well known purpose. In consequence, field connections have been brought through both devices, Whereby an unnecessary complication of circuits has been entailed.

According to our invention, we provide a single structure embodyin switching means respectively having the auctions of a reverser and field change-over switch and likewise being provided with other conducting means. whereby the said connections are simplified, and operation of the system becomes easier and less expensive. The combined structure is adapted to assume two positions in each of the forward-running and reverse-running directions. The first step in either direction serves to directly connect or reverse the field winding connections of the machine or machines, and the second step serves to eliminate a portion of the field winding 0r windings.

In addition, we provide an electrically controlled, fluid-pressure operated mechanism for actuating the combined structure outlined above that comprises a piston adapted to reciprocate in a cylinder, and a pair of electro-magnetically actuated valves for admitting fluid pressure to the respective ends of the cylinder when energized througha plurality of interlocking contact members that are disposed on the combined structure, with the exception of one contact member which is associated with a resistor switch, and that are adapted for suitable circuit connections with a master controller. The contact members referred to are so arranged that, when one valve magnet has been energized through the master controller to actuate the reverser to a field-changing position after the motors are connected in full series relation, and the controller is moved beyond its corresponding position, the first valve magnet is deenergized and the second magnet is automatically energized, whereby the reverser is returned to its full field position before the transition from series to parallel circuit relation of the motors is effected. The return actuation is thus positive and reliable and is not dependent upon the use of springs or similar devices such as have sometimes been employed heretofore in control apparatus.

In the accompanying drawing, Figure 1 is a diagrammatic view of a control system embodying our invention, the actuating mechanism under consideration being shown in section, for clearness, and Fig. 2 is a chart of familiar form showing the sequence of operation of the switches. Although, for illustrative purposes, we have shown our invention in connection with an old and well-known control system, it will be understood that the invention is not restricted in its use to any one type of control system.

Referring to the drawing. the system here shown comprises a supply-circuit conductor which is marked Trolley; a pair of electric motors having armatures marked respectively M and M and field magnet windings marked respectively F and F; a plurality of main-circuit resistor sections, one of which may be short-circuited by a switch R and another by a switch R a plurality of control switches of a familiar type Ls, M, P, S and G for efi'ecting the desired circuit changes; a master controller MC and a master reverser MR for energizing the control switches through a suitable control resistor CR and adapted to assume a plurality of motor-accelerating positions a to g, inclusive; a main-circuit and control circuit apparatus marked Field changeover and reverser and having the combined functions implied by the name; an electrically controlled, pneumatically-operated actuator 1 for the apparatus just referred to; and a suitable source FP of fluid pressure for the actuator.

The general construction of the combined field change-over and reverser is preferably similar to that of the familiar controller drums, although the .reverser is here shown developed into a single phase, for convenience of illustration. The apparatus is adapted to assume two operative positions in either direction from an imaginary off position, the first position in one direction corresponding to the forward running osition and the first position in the opposite direction corresponding to. the reverse running position, the second position in either case serving to change from 'full field to normal field connections of the motors, for a purpose well-known in the art.

The actuator 1 comprises a piston "2; a suitable cylinder or casing 3 therefor; a pair of magnet valves 4 and 5 of familiar construction, which are normally closed to admit atmospheric pressure only to the cyl-- inder 3, and which are adapted, when energized, to open and admit fluid pressure from any suitable source, as the tank FP, to the respective ends of the cylinder; and an oscillating link 6 operatively a$ociated with the piston 2 and suitably secured to the field change-oi'er and reverser, whereby rotative movement of the latter is eflected. The duplex'piston 2 may be of any suitable construction and, preferably, has the link 6 oscillatably mounted intermediate the ends of the piston. Assuming the actuator to be in the forward running position as shown in the drawing,'the valves 4 and 5 being closed, the operation of the actuator may be described as follows: Upon'the energization of the coils 7 or 7", as hereinafter described, the corresponding valve opens, thus making'communication with the source FF and I admitting fluid pressure to the corresponding end of the cylinder, whereby a movement of the piston away from that end ensues. To stop such movement, it is merely necessary to deenergize the valve-magnet coil in circuit, whereupon the valve closes to release the cylinder pressure and arrest the motion of the erative position.

The field change-over and reverser here shown has the several sets of main contact members for reversing the motor connecpiston at any desired options and for changing the amount of field magnet windings in circuit, disposed on the upper portion of the structure, and has the auxiliary, control circuit contact members master controller to its position a, a control circuit is established from the trolley, through a conductor 8, control fingers 9 and 10which are bridged by a contact segment 11-a conductor 12, control resistor CR and conductors 13 and 14 to ground. Another circuit is established through a conductor 15, control fingers 16 and l7which are bridged by a contact member 18 of the master reverser MRa conductor 19, control fingers 20 and 21which are bridged by a contact member 22 of the field changeover and reverserc0nductor 23 and the. coil of the reversing valve 5, to ground,

thus energizing the reversing coil of the re verser, which is thereupon actuated to its reverse running position, designated as RFF, by the actuator 1, thecontrol cir cuit being broken at the contact member 22. A similar and readily traced set of circuits is employed to cause a similar actuation of the reverser from the above-described reversedrunning position to the forward position shown in the drawing. In position a, of the master controller, if the master reverser has been thrown to its forward position, a circuit is established from the conductor 15, through control fingers 16 and 24 which are bridged by contact member 25 of the master reverser, conductor 26, control finger 27 of the field change-over and reverser, contact members 28 and 29, control finger 30, conductor 31, auxiliary contact members 32 of an overload trip switch O,T., and the coil of the line switch LS to anegative conductor 33. The line switch is thus In positions I) and 0, the resistor switches R and R are respectively closed, thereby disposing the motors in full series relation. Inasmuch as this method of operation is familiar to those skilled in the art, no further description thereof is deemed necessary. In position d, an energized contact member 34 of the master controller engages a control finger 35, whence circuit is completed through a conductor 36, control fingers 37 and 38 which respectively engage contact members 39 and 40 and conductor 41 to the coil of the valve 4. The field changeover and reverser is thus moved to the second or field-changing position, designated as FNF. It will be observed that-the above-mentioned connections of the line switch coil are maintained throughout the movement of the reverser. When the re; verser is moved to its second position, by reason of the peculiar shape of the maincircuit contact members 42 and 43, contact is broken with control fingers 44 and 45, and

circuit is made with control fingers 46 and 47, respectively. Fingers 44 and 45 are re spectively connected to one end of the field windings F and F and the fingers 46 and 47 to intermediate points of the respective windings and, therefore, the full field connections of the motors are severally changed to the normal field connections and a higher speed is obtained.

The new control circuits established in the normal field position of the reverser may be traced as follows: from the energized control segment 28, control finger 48, conductor 49, stationary contact member 50, at present not connected, but that are adapted to be bridged by a contact member marked R out, when the switch R opens to its lower position, conductor 51, control-fingers 52 and 21, that are bridged by the contact member 22, and the conductor 23 to the coil of the reversing valve 5.

By reason of the above described arrangement of circuits, when, during the actuation of the controller from position 0! to position 6, the circuit of the coil of the forward valve 4 is broken at the master controller contact member 34 and the circuit of the coil of switch R is interrupted at an adjacent contact member 53, the circuit of the coil of the reversing valve is completed through the contact member marked R out and the field change-over and the reverser is, consequently, returned to its full field position, before the transition of the motors to parallel circuit relation is effected by the closing of switch G, the opening of switch S and the closing of switch P, as indicated in Fig. 2. The switch R is then closed and the reverser is again actuated to positions 7 and g, respectively, in a manner similar to that hereinbefore described.

It will be understood that an operation of the reverser similar to that just recited will occur when the apparatus occupies its reverse running position, designated as RFF, upon the movement of the master controller MC to either of its positions (Z or g. 'It will also be understood that the actuation of the field change-over and reverser from the forward to the reversed position, or vice versa, reverses the connections of the field winding F and F through the medium of certain of the contact members located upon the lower end of the combined apparatus and the corresponding control fingers, in a well-known manner, detailed description of which is not deemed necessary here.

We do not wish to be restricted to the particular circuit connections and arrangement of parts herein set forth, but desire that only such limitations shall be imposed as are indicated in the appended claims.

We claim as our invention:

1. The combination with an electric motor, of a controller'therefor comprising a single switching device having main circuit connections for reversing the motor and for changing the field strength thereof, and electro-magnetic actuating means dependent for energization under predetermined conditions upon the position of said device.

2. The combination with a power-operated member, and electrical means for governing the movement thereof, of a switching device for electric motors operatively associated with said member and comprising means for reversing the motors upon occupation of predetermined positions of the device and for also changing the motor field strengths upon occupation of other positions, and electrical interlocking means for automatically biasing said device to certain of said positions under predetermined conditions of motor operation.

3. The combination with a plurality of motors adapted for-series-parallel operation, a poweroperated member, and electrical means for governing the movement thereof, of a switching device-for said motors operatively associated with said member and having initial positions corresponding to forward and reverse running, respectively, and having corresponding subsequent positions that are also adapted for changing the motor field strengths, and electrical interlocking means for automatically returning said device to the corresponding initial position from either of said subsequent positions upon operation of the motors from series to parallel relation.

4. A controller for electric motors comprising a single switching device adapted to assume a plurality of positions in either a forward or a reverse direction, the initial positions corresponding to forward and reverse running, respectively, and the subsequent positions being also adapted to change the amounts of the motor field windings in circuit, and controllable electro-mechanical means for controlling said device.

5. A controller for electric motors com prising a single switching device having circuit connections for reversing the motors and for independently changing the field strengths thereof, and an actuating means forsaid device comprising a movable member attached thereto, a piston operatively connected to said member, means for admitting fluid pressure to opposite sides of said piston, and electrical means for controlling the pressure admission.

6. The combination with a controller for electric motors comprising a single switching device having main circuit connections for reversing the motors and for changing the field strengths thereof, of an electrically controlled actuating device for said controller, and a plurality of contact members disposed thereon for governing the circuits of said electrically-controlled device.

7 The combination with a controller for electric motors comprising a single switching device having main circuit connections for reversing the motors and for changing the field strengths thereof, of an electrically controlled actuating device for said controller, a plurality of contact members disposed thereon for governing the circuits of said electrically controlled device, and an auxiliary apparatus for controllably supplying energy through said contact members to said circuits.

8. The combination with a controller for electric motors comprising a single switching device having main circuit connections for reversing the motors and for changing the field strengths thereof of power-operated means for actuating said controller, a pair of electro-magnetically actuatedvalves for respectively controlling movement of said means in opposite directions, a supply circuit, an auxiliary controller, and a plurality of sets of contact members disposed onsaid switching device and arranged to govern the energization of the magnet valve circuits from the master controller and the supply circuit.

9. The combination with a supply circuit and a plurality of electric motors, of a single switching device having initial portions, and provided with circuit connections, for forward and reverse running, respectively, of the motors, and having corresponding subsequent positions, and provided with circuit connections for changing the motor field strengths, of fluid-pressure operated pistons for actuating said controller, a cylinder in which the piston operates, a pair of electrically-governed magnet valves for respectively controlling the admission and release of'fluid pressure on opposite sides of said piston, a master controller connected to said supply circuit, and a plurality of interlocking contact members disposed on said switching device to govern the supply of energy from said controller to said magnet valves for producing a step-by-step movement of the switching device in either direction.

10. In a control system, the combination with an electric motor, an accelerating resistor, a plurality of motor-control switches, and a master switch, of a switching device having circuit connections for reversing the motor and for independently changing the field strength thereof, and an electromagnetically controlled actuating means for the device.

11. In a control system, the combination with an electric motor, an accelerating resistor, a plurality of control switches and a master controller, of a switching device having a plurality of main and auxiliary con tact members, and an actuator for said device comprising a piston operatively connected thereto, a cylinder in which the piston operates, a pair of normally closed valves for controlling the admission of fluid pressure to the respective ends of the cylinder, and electrical means dependent upon the positions of said master controller and said auxiliary contact members for governing the valves.

12. The combination with a supply circuit and a plurality of electric motors, of a single swltching device adapted to assume a plurality of positions in either a forward or a reverse direction, the initial positions corresponding to forward and reverse running, respectively, and the subsequent positions being also adapted to change the amounts of the motor field windings in circuit, an actuator comprising a movable member attached to said device, a piston operatively connected to said movable member, a cylinder in which the piston operates, a pair of electrically-controlled valves for admitting fluid pressure on opposite sides of said piston to produce a movement thereof in the one or the other direction, a master controller, and a plurality-of sets of interlocking contact members disposed and arranged on said switching device to severally govern the electrical connections of said valves to said supply circuit, in conjunction with said controller, to selectively produce movement of said device into any of its operative positions.

13. The combination with a'power-operated member, electrical means for governing the movement thereof, and an auxiliary circuit controller, of a switching device for electric motors associated with said member and comprising means for reversing the motors and for changing the field strengths thereof, and means for controlling said elecineaear trical means, whereby a predetermined movement of said power-operated member is produced by actuation of said auxiliary circuit controller and whereby said member is returned to its initial position upon subsequent actuation of said controller.

14. The combination with a power-operated member, electrical means for governing the movement thereof, and a master controller, of a switching device for electric motors associated with said member and comprising circuit connections for reversing the motors and for changing the field strengths thereof and other circuit connections for controlling said electrical means in conjunction with said master controller, whereby a predetermined actuation of said controller energizes said electrical means to move said device to its field-changing position and whereby further actuation of the-controller automatically energizes said electrical means to return said device to its original position.

15. The combination with a multi-position power-member, a pair of magnets for oppositely governing the movement thereof, and a master controller, of a switching device operatively connected to said member and having initial positions, and provided with circult connections for forward and reverse running, respectively, of the motors, and having corresponding subsequent positions, and provided with circuit connections for changing the motor field strengths, auxiliary contact making means disposed on said device for energizing certain of said magnets in a predetermined position of said master controller to move said power-memher to its field-changing position, and means associated with another portion of the motor circuit for acting in conjunction with said auxiliary contacting means to deenergize said certain magnet and energize the magnet to return said device to its initial position when the master controller is moved out of said predetermined position.

16. The combination with a supply circuit, an electric motor, a plurality of accelerating resistors, a plurality of short-circuiting switches therefor, a plurality of actuating coils for said switches, of a multi-position piston, an operating cylinder therefor, a pair of magnet valves for admitting fluid pressure to opposite sides of said piston, a switching device operatively connected to the piston and adapted to assume a plurality of positions in either a forward or a reverse direction, the initial and normal positions corresponding to forward and reverse running, respectively, and the subsequent positions being also adapted to change the amounts of the motor field windings in circuit, auxiliary contact making means disposed on said device for energizing certain of said valve magnets in a predetermined position of the master controller to temporarily move said piston and said device to the corresponding subsequent position, and interlocking contact means associated with one of the resistor short-circuiting switches for completing the circuit of the second valve magnet to return said device to its normal position when the master controller is actuated beyond said predetermined position to deenergize said first valve magnet and the coil of said short-circuiting switch. In testimony whereof, we have hereunto subscribed our names this 27th day of Feb, 1914.

NQRMAN l V. STOREE. ARTHUR J. HALL.

Witnesses:

JACOB STAIR, J12, B. B. HINES.

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