US1244459A - Control system. - Google Patents

Description

H. L. BEACH.

CONTROL SYSTEM.

APPLICATION FILED SEPT. a. 1914.

1,244,459. Patented Oct. 30, 1917.

2 MW. F .WM. m FofleyE/V/ r/Jb 3 WITNESSES: mvamon Howard L. Beach.

. I Envy/ref M09 22 20 UNITED STATES PATENT OFFICE.

HOWARD I1. BEACH, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR T0 WESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

CONTROL SYSTEM.

Specification of Letters Patent.

Application filed September 8, 1914. Serial No. 860,605.

Toiall whom it may concern:

Be it known that I, HOWARD L. BEACH, a citizenof the United States, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Control Systems, of which the following is a specification.

My invention relates to systems of control for electric motors, and it has special reference to the control of electric motors that are adapted for use in propelling electric railway vehicles and the like.

One object of my invention is to simplify, and reduce the cost of construction and maintenance of control systems of the aboveindicated character.

Another object of my invention is to increase the flexibility and efliciency of operation of systems of the general type under consideration. I

In many types of control systems for electric railway vehicles thatemploy auxiliary control circuits for electrically governing a plurality of power-operated, particularly fluid-pressure operated, switches, it is customary practice to control the operation of the switches directly from the auxiliary control circuit through a suitablemaster con troller. In the case of automatic systems, in addition to the apparatus mentioned, it is necessary to provide an accelerating relay or limit switch, which is set to operate upon the traversal therethrough of a predetermined current value, and also a multiplicity of electricalinterlocking contact members that are associated with corresponding control fingers and are actuated by the respective switches to energize the magnet coils of the switches, in accordance with a predetermined sequence, to effect automatic progressive operation of the several motor-controlling switches.

Disadvantages of this type of control system are the inflexibility of operation, inasmuch as all of the switches which are dependent upon the accelerating relay must operate at the same current value, and the first cost and maintenance of the large number of interlocking contact members: It is, therefore, with the purpose of obviating these disadvantages that my invention is designed.

According to my invention, I reduce to a necessary minimum the. number of switches that are governed directly from the auxiliary control circuit and also the number of electrical interlocking contact members that are carried by the switches; and to effect automatic acceleration, I provide a pluralityof adjustable electro-magnetic devices which are connected in series-circuit relation with the motors and are mechanically actuated by the switch that closes, just prior in the sequence, to efi'ect fluid-pressure operation of the respective switches when the current decreases to a predetermined value. In this way, the use of a separate accelerating relay or limit switch is obviated and each switching device may be adjusted to close at the proper and most efficient time and at the most suitable individual current value, irrespective of the conditions which determine the operation of any other switch.

In the accompanying drawing, Figure 1 is a diagrammatic view of the main circuits of a system of control embodying my invention; Fig. 2 is a diagrammatic view of the auxiliary control circuits that are adapted for operating the motor controlling switches shown in Fig. 1 in accordance with the sequence chart, Fig. 3, of well-known form; Fig. 4 is a diagrammatic view illustrating the general arrangement of the two types of switching devices which are employed in the control system shown in Fig. 1; and Fig. 5 is a sectional detail view of certain of the switching devices illustrated in Fig. 4.

Reference may first be had to Fig. 5, which illustrates the preferred form of one type of switching device that is employed in the systems shown in Figs. 1 and 4, the device showing, for example, the relation of the switch R11 to the electromagnetic device that is associated with the switch R A stationary switch member 1 is supported in position in any suitable and familiar manner (not shown), and a cooperating movable contact member 1 is suitably insulated from, and is movable with, a rod 2 to the lower end of which is secured a piston 3 which operates within a cylinder 4 in opposition to the action of a helical spring 5. A suitable inlet pipe 6 is provided to admit fluid-pressure from any suitable source (not shown). A pin 7 is secured near the free end of the rod 2, for a purpose hereinafter specified. It will be understood that any other suitable type of. fluid pressure-operated device may be mployed,

if desired. The electro-magnetic valve illustrated in the figure comprises a suitable incasing member 11 which is provided with a cap having a hollow raised central portion or hub 12; a coil 13 of relatively large current capacity which is disposed within the incasing member 11 and which is adapted for connection in the main motor circuits, as indicated in Fig. 1; a centrally disposed movable core 14 which cooperates with a stationary longitudinally adjustable core 15 and is separated therefrom by a suitable air gap 16; a valve member 17 which is suitably secured to the lower end of the core 14 and is biased by a spring member 18 to close an inlet passage or pipe 19 from the source of fluid-pressure; an exhaust chamber 20 which is normally in communication with a passage or pipe 21 leading to the operat ing cylinder of the corresponding switch; a second valve member 22 which is adapted to close communication between the chamber 20 and the passage 21 upon actuation of the electro-magnetic device; a rod 23 which is secured to the upper end of the core 14 and is movable therewith; a loose collar 24 which is disposed near the upper end of the rod 23; a second collar 25 which is rigidly secured to an intermediate point of the rod 23; a helical spring 26 which is supported upon the upper surface of the hub 12 and is adapted to bias the collar 24 and the rod 23 to their upper positions, a second helical spring 27 which is disposed around the rod 23 between the inner flat surface of the hub 12 and the collar 25, and is adapted to bias the rod 23 and the associated valve member 17 to its lower posi tion; a pin 28 which is secured to opposite sides of the collar 24 and extends through a longitudinally disposed slot 29 in the rod 23; and an oscillating rod or lever 30, one looped end 31 of which extends around the rod 23 and rests upon the collar 24 and is pivoted at an intermediate point 32 to have its free end engaged by the pin 7 of the rod 2, under predetermined conditions.

The electromagnetic action of the coil 13 tends to maintain the valve'17 closed, and, therefore, the coil 13 and the upper spring 26 act in conjunction with each other and in common opposition to the action of the spring 27. With no current flowing, the action of the spring 26 predominates over that of the spring 27, and the valve 17 remains closed; also, the electromagnetic force exerted by the coil 13, while the motor current traversing the coil is maintained above predetermined value, is suflieient to overcome the action of the spring 27, even though the spring 26 be temporarily rendered inoperative upon the rod 23, as hereinafter described. The current value at which the device operates may be readily varied to suit the particular conditions and to obtain the most efficient operation by adjusting the position of the stationary core 15 relative to the movable core 14.

The operation of the device just described may be set forth as follows: Upon closure of the switch RR by the admission of fluidpressure to the cylinder 4, the pin 7 of the rod 2 engages the free end of the rod 30, and, consequently, depresses the other end 31 of the rod, causing the coller 24 to be actuated downwardly, a movement which is permitted by the pin and slot construction. The actuation of the spring 26 upon the rod 23 and associated valve member 17 is thus relieved. However, so long as the motor current passing through the coil 13 remains above a predetermined value, the electromagnetic action of the coil is sufficient to overcome the action of the spring 27, and no further operation of the electromagnetic device occurs. When the current drops below the predetermined value, however, the action of the spring 27 becomes greater than the force exerted by the coil 13, and the valve member 17 is actuated to its lower position to admit fluidpressure to the coresponding cylinder, thereby closing the switch. The switch is then maintained in its closed position, irrespective of further variations in the motor current, by the disposal of the coil 13 in a circuit which receives only a small portion of the motor current, or by opening the circuit of the coil 13, as hereinafter set forth.

The opening action of the device illustrated is effected as follows: Upon the opening of the switch with which the device is mechanically associated, the pin 7 is disengaged fromthe free end of the rod 30, whereupon the spring 26 overcomes the action of the spring 27 and actuates the rod 23 and its associated valve member 17 to their upper positions to permit of the release of fluid pressure from the operating cylinder of the corresponding switch through the passage 21 and the exhaust chamber 20.

As indicated in Fig. 4, the switching device construction just described applies to the switches RIP, M R, RR and R, which are respectively adapted for the described actuation, by the switches JR or M, J or G, RR- R and RR". The other switches illustrated in Figs. 1 and 4, namely, JR, J, G, S and M are of a familiar fluidpressure type which are electrically-governed from an auxiliary control circuit, and are substantially of the construction illustrated below the dotted line C-C in the electromagnetic device R of Fig. 5; the magnet coil, of course, in this case comprising a relatively larger number of turns of fine wire, since the coil is adapted for operation from a materially higher voltage. The fluid-pressure-operated piston and cylinder for the switches referred to may be of any 1'30 shown in Figs. 1 and 4 as directly electromagnetically actuated.

' Referring. to Fig. 1, the system here shown is of a familiar series-parallel type which employs bridging transition during the operation of the motors from series tov parallel relation and comprises a supply circuit conductor marked .Trollyl; a. return circuit conductor marked Ground; a plurality of electric motors respectively pro vided with armatures A and A and field magnet windings F and F .a plurality of motor-controlling switches M M JR, J and G; a plurality of accelerating resistors, one of which is adapted to be short-circuited by a switch S and is employed during series operation only of the motors, and others of which are adapted to be short-circuited by switches R R RR and RR respectively, and a reversing switch RS, of familiar construction, which is adapted to simultaneously reverse the electrical relations of the field windings F and F with respect to. the corresponding armatures. The association of the series-connected coils 13 with the corresponding switches is indicatedby the respective arrows.

Reference may now be had to Fig. 2, in which the apparatus shown comprises, in addition to the actuating coils of the switches S, J, G, J R and M and the various electrically interlocking contact members which are associated therewith, an auxiliary source of energy, such as a storage battery SB or any othersuitable means, a ,master controller MC, a master reverser MR and the auxiliary control circuits for the opera tion of the reversing switch RS.

The master reverser is adapted to assume an ofi,. a forward and a reverse position, in accordance with customary practice; and the master controller is adapted to assume a plurality of motor-operating positions at, 7) and c. The system illustrated is entirely automatic, and,'if it is desired to opcrate the motors without interruption from starting to full parallel relation, themaster controller may be .moved immediately to its final operating position a. If it is desired to operate the motors to full series relation only, this may be efl'ected by move ment of the master controller to its intermediate operating position 7), and the actuation of the controller to its initial position a will merely connect themotors in series circuit relation with all of the accelerating resistors.

Assuming that the, master reverser MR and the reversing switch RS are moved to their corresponding forward running positions and that the master controller MC is actuated to its final operating position 0, the

operation of the control system may be described as follows: Energy is supplied from one terminal 13-}- of the storage battery SB through conductor 40, control, fingers 41 and 42, which are bridged by a contact member 43 of the master controller, conductor 44, control fingers 45 and 46, which are bridged by an interlocking contact member 47 of the master reverser, conductor 48, fingers 49 and 50, which are bridged by a contact member 51 of the reversing switch RS, conductor 52, and the actuating coil of the switch l 1 to conductor 53, which is connected to the opposite terminal of the battery SE. A second circuit is completed from conductor 52 through conductor 54, the actuating coil of the switch J R, conductor 55, interlocking contact member 56, which occupies the position shown when the switch J occupies its out position, conductor 57 interlocking contact member 58 of the switch M in its out position, and conductors 59 and 53 to the negative battery terminal. The switches M and JR are thus closed to connect the motors in series-circuit relation,

with all of the accelerating resistors across the supply circuit.

Substantially concurrently with the operation of the above-mentioned switches, a circuit is established from an energized contact segment 67 of the master controller through control finger 68, conductor 69, the energizing coil of switch S, and conductor 57 back to the negative conductor 53. Upon the closure of switch S, the oscillating rod 63 (Fig. 4) is mechanically actuated to opcrate the electromagnetic device 64, which is associated with the switch RR in a manner hereinbefore described. The closure of the switch RR actuates a rod 65 to operate the electromagnetic device 66, which is associated with the switch R The switches RR and R are similarly actuated in progression, dependent upon the particular adjustment of the corresponding electromagnetic devices. All of the resistor short-circuiting switches are then closed, and the motors are disposed in full series relation. It will be noted that the resistor short-circuiting switches which are dependent for their actuation upon an electromagnetic device similar to that illustrated in Fig. 5, severally serve to dispose their actuating coil 13 in a parallel circuit with the movable con tact member of the respective switch upon closure thereof (best shown in Fig. l) consequently, the current flowing through the coil is not of a suiiiciently high value to cause any further operation of the electromagnetic device, and the switch, therefore,

finger 71 whence circuit is completed through conductor 72, the actuating coil of the switch J, control fingers 73 and 74, which are bridged by an interlocking contact member 7 5 when the switch J occupies its open position, conductor 7 6, control fingers 7S and 7 9, which are bridged by interlocking contact member 80 when the switch R occupies its closed position, conductors 81 and 81 control fingers 82' and 88, which are bridged by the contact member 58 of the switch M in its open position, and conductor 59 to the negative conductor 53. After the switch J is closed, the energizing circuit of its actuating coil is transferred to the conductor 84, which is connected with the conductor 81 The closure of the switch J effects the deenergization of the actuating coil of the switch JR by the interruption of the coil circuit at the contact member 56. The switches RR to R inclusive, are then successively and rapidly opened, in the manner hereinbefore described. It should be noted that the switch S and the associated resistor are excluded from the circuit. by the opening of the switch JR. j

Also, upon the closure of the switch J, the mechanically-associated oscillating rod 85 is actuated to operate the electromagnetic device 86, which is associated with the switch M as indicated in Fig. 4. The closure of the switch M closes the switch G by reason of the energization of a circuit including conductor 54, the actuating coil of the switch, conductor 87, interlocking contact member 88 of the switch R in its open position, conductor 89, control fingers 90 and 83, which are bridged by the contact member 58 of the switch M when the latter occupies its closed position, as hereinbefore described; and conductor 59 to the return circuit conductor 53. Upon the closure of the switch G, the energizing circuit of its actuating coil is transferred to control fingers 91 and 92, which are bridged by an interlocking contact member 93 of the switch G in its closed position, and conductor 94, to the finger 90.

The closure of the switch M also opens the energizing coil circuit of the switch J at the contact member 58, thereby opening the switch J preferably just subsequent to the closure of the switch G. The switch M is thus maintained closed by the action of a. rod 85, that is actuated by the switch G, upon the electromagnetic device 86, before the rod 85 is rendered inoperative by the opening of the switch J. The resistor shortcircuiting switches are opened before the closure of the switch G, however, thereby precluding the possibility of short-circuit across the supply circuit through the switches M J and G.

The closure of the switch M also mechanically actuates the device 64, which is associated with the switch RR, similarly to the actuation thereof by the closure of the switch S, as hereinbefore described, and as indicated in Fig. 4. The successive closure of the remaining resistor short-circuiting switches R RR and R is accomplished in the same manner as that hereinbefore set forth. The motors are thus connected in full parallel relation.

I do not wish to be restricted to the specific circuit connections, arrangement of parts, or structural details herein set forth, as many modifications thereof may be made within the spirit and scope of my invention. I, therefore, desire that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. In a system of control, the combination with a plurality of electric motors, of means for automatically effecting series-parallel operation thereof, said means embodying a plurality of fluid-pressure operated motorcontrolling switches, a plurality of electromagnetic devices for respectively delivering fluid pressure to certain of said switches under predetermined conditions, and mechanical means operated upon the closure of certain switches for respectively actuating the electromagnetic device associated with the next succeeding switch to close said switch when the motor current assumes a. predetermined value.

2. In a system of control, the combination with a plurality of electric motors, of means for automatically effecting series-parallel operation thereof, said means com rising an auxiliary control circuit, a control er, a lurality of electromagnetic devices adapted to be connected in circuit with the motors, and a plurality of fluid-pressure operated, motor-controlling switches, certain of which are governed through said controller from said control circuit, and others of which are dependent for operation upon the mechanical actuation of the corresponding electromagnetic device by the closure of a certain switch and upon the traversal of a predetermined current through said corresponding device.

3. In a system of control, the combination with a main supply circuit and an electric motor supplied therefrom, of a plurality of fluid-pressure operated motor-controlling switches, certain of which are electrically governed and others of which are respectively dependent for operation upon electrical means adapted for mechanical actuation by other switches under predetermined conditions.

4. In a system of control, the combination with a main supply circuit and an electric motor supplied therefrom, of an auxiliary supply circuit, a plurality of fluid-pressure operated motor-controlling switches, certain of which are electrically governed from said auxiliary supply circuit and others of which are respectively dependent for operation upon means mechanically actuated by the movement of other switches when the motor current assumes a predetermined value.

5. In a system of control, the combination with a main supply circuit, an electric motor supplied therefrom, and an auxiliary supply circuit, of a controller, a plurality of elec tro-magnetic devices adapted to be connected in circuit with the motor, and a plurality of fluid-pressure operated, mot0r-controlling switches, certain of which are governed through said controller from said supply circuit and others of which are dependent for operation upon the mechanical actuation of the corresponding electromagnetic device by the closure of a certain switch and upon the traversal of a predetermined current through said corresponding device.

6. In a system of control, the combination with a main supply circuit and an electric motor supplied therefrom, of a controller, an auxiliarysupply circuit, a plurality of electromagnetically-operated, fluid-pressure controlling valves adapted to be connected in circuit with the motor, and a plurality of fluid-pressure operated, motorcontrolling switches, certain of which are directly governed through said controller from said supply circuit and others of which are operated upon the mechanical actuation of the corresponding valve by the closure of a certain switch and upon the concurrent traversal of a predetermined relatively low motor current through said Valve.

7. In a system of control, the combination with an electric motor, of a plurality of motor-controlling, fluid-pressure governing switching devices including fluid-pressure operated members, one of which devices is directly electrically governed and others of which are thereupon mechanically actuated successively, according to the value of motor current, to admit fluid pressure to the corresponding fluid-pressure operated member.

8. In a system of control, the combination with an electric motor, of a plurality of fluid-pressure operated motor-controlling switches, means for electrically governing one of said switches irrespective of motor operation, and means dependent upon the value of motor current for mechanically successively actuating a plurality of other switches.

9. A switching device comprising a plurality of cooperating stationary and movable contact members, a fluid-pressure operated device for actuating the movable memher, and means dependent upon a predetermined current value and upon external mechanical actuation for admitting fluid pressure to said device.

10. A switching device comprising a plurality of cooperating stationary and movable contact members, a fluid-pressure operated device for actuating the movable member, and electromagnetic means dependent upon external mechanical actuation for admitting fluid pressure to said device when the electromagnetic force exerted by said means decreases below a predetermined value.

11. A switching device comprising a plu rality of cooperating stationary and movable contact members, a fluid-pressure oper ated device for actuating the movable memher, a valve for admitting fluid pressure to said device and normally biased to its closed position, adjustable electromagnetic means tending to hold the valve closed, and external mechanical means dependent upon the force exerted by said electromagnetic means for opening said valve to effect engagement of said contact members.

In testimony whereof, I have hereunto subscribed my name this 25th day of Au 1914.

HOWARD L. BEACH.

I Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

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