US806709A - Switch-operating mechanism. - Google Patents

Description

PATENTED DEC. 5, 1905.

J. s. PEVEAB. SWITCH OPERATING MECHANISM.

APPLIOATION FILED FEB. 27.1905.

lm enmr Jsse d. Pens-an UNITED STATES PATENT OFFICE.

JESSE S. PEVEAR, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SWITCH-OPERATING MECHANISM.

Specification of Letters Patent.

Patented Dec. 5, 1905.

Application filed February 27, 1905. Serial No. 247,440.

1'0 ctZZ whom, it mayconcern:

Be it known that I, J ESSE S. PEVEAR, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Switch-Operating Mechanisms, of which the following is a specification.

The present invention relates to switches which are actuated selectivelyas, for instance, in apparatus arranged for operation on both alternating and direct currents, wherein different switches are employed for connecting the apparatus to the source of currentsupply, according as the current which is be ing supplied is alternating or direct. Such mechanism is particularly applicable to electric-railway service in which a portion of the line is supplied with alternating current and another portion with direct current. In this latter instance plural switch apparatus is almost always necessary, for the reason that the alternating current is supplied to the trolley at a high potential, and the potential is reduced to the proper value by means of a transformer carried upon the car itself, and since the direct current cannot pass through the transformer separate switches must be provided for use on alternating and direct currents, respectively.

It is of advantage to make changes in the internal connections of the motors themselves in passing from one form of current to the other, inasmuch as a motor wound for efficient operation on alternating current generally requires some change either in the control-circuit or in the connections of the motorwindings for most efficient operation upon direct current, and a controlling-switch or commutating-switch is provided for making the desired changes in the motor-windings themselves when changing from one current to another. For this reason, also, it is desirable to have a plurality of main switches in order that current may not be supplied to and through the commutating-switch except when it and one of the main switches are in corresponding positions.

In my prior application, Serial No. 220,166, for improvements in motor control there is disclosed a system of the character specified in which the two main switches are interlocked, so that both may not be closed at the same time. The handle for operating these switches serves also to operate the commutating-switch,

the arrangement being such that the handle cannot be removed from engagement with the main switches except when they are both open. This construction makes it necessary for the motorman when changing over from alternating current to direct current, or vice versa, to first open both main switches before the commutating-switch may be operated to its proper running position and prevents him from afterward again moving the commutating-switch unless and until the main switches are again both open.

The manual operation of the main switches of course requires more or less attention on the part of the motorman and requires some time for its accomplishment. Also where it is necessary to operate the main switch manually the car must be brought to a stop or else a comparatively long dead section of trolley must be employed for separating the alternating-current wire from the direct-current wire in order to allow sufiicient time for operating the switch mechanism while the car continues in motion.

Oneobject of the present invention is to so construct and arrange main-switch mechanism of the character described that a main switch is automatically closed by current from the source of supply and immediately opens when the flow of current is interrupted.

A further object of the present invention is to so arrange the automatic operating means for switch mechanism of the character described that only one of a plurality of switches may be closed at a time.

A further objectof the present invention consists in a simple and novel construction and arrangement of parts whereby a number of switches are selectively operated, according as the current supplied to the actuating means is alternating or direct.

Further objects of the present invention will appear in connection with the following description thereof.

One form of the present invention is illustrated in the accompanying drawing, which illustrates diagrammatically a portion of a car equipment and automatically-actuated switch mechanism for connecting'it to the source of current-supply.

Similar reference characters will be used throughout the specification and drawing to indicate like parts. X indicates a trolleywire or third rail at the point of junction of the portions 1 and 2, which are energized by direct and by alternating currents,respectively. 3 indicates an insulated or dead section connectingthe live sections'l and 2. T and T are trolleys or other current-collecting devices, adapted to make contact with the trolley-wire or third rail X. D and A are two main switches carried by the car and are respectively adapted to connect the motor and control apparatus to the collecting device when direct current or alternating current is being supplied. E and E are commutatingswitches, which may be simple switches for connecting the control apparatus to trolley or may have other functions similar to those of the commutating-switch in my aforesaid application. C and C are controllers. All these parts may have any usual or desired construction, since they in themselves form no part of the present invention, except as will be hereinafter specified.

The switch D consists of a movable member 0Z, adapted to engage with fixed contacts (Z, together with an auxiliary contact device, which consists of a movable contact member 03 arranged to engage with fixed contacts (i These contacts may all be placed within an oil-receptacle of the character shown in my aforesaid application, and the movable members d and d may both be carried by single stem d, although this particular arrangement of parts is not essential, since the main and auxiliary switches may have anysuitable construction and may be operatively connected together in any suitable manner,whereby the auxiliary contacts are caused to open when the main contacts are closed. Switch A is similar to the switch D and comprises members a to (0*, which correspond, respectively, to the members 0? to d.

When the main switch D is closed, current is supplied from the trolley through wire 5, contacts cl and (1", wire 6 to fixed contact 6 of commutating-switch E, and to a similar contact in commutating-switch E, if two commutating-switchesare'employed. Similarly, if the main switch A is closed current will be supplied from the trolley through wire 7, contacts a a, transformer F, wire 8, to contact e of the commutating-switch E. The commutating-switch is provided with a third fixed contact 6 which may be connected to a fixed contact 0 on the controller C. The commutating-switch is provided with movable contact-segments e and 6*, so arranged. that when the switch is thrown in one direction fixed contacts e and e are connected together, and when the switch is in the other running position contacts e and e are connected together, in the one case supplying the motor and control apparatus with direct current and in the other with alternating current.

The means for operating the main switche automatically and selectively is as follows: One of each of the sets of fixed auxiliary contacts (Z and a is permanently connected to the trolley by means of the wire 9 and preferably a resistance 7. Normally when no current is being supplied to the trolley both main switches are open, and therefore both auxiliary switches .closed. Assuming that trolley T receives direct current, this current will flow through the resistance a, wire 9, the auxiliary switch associated with main switch A, reactance R, switch S, coil D to ground, thereby energizing coil D. The coil D controls the switch D in any suitable manner as, for instance, by acting upon a magnetic core 10, which is operatively connected to the stern d by suitable lever mechanism 11, so constructed and arranged that when the coil D is energized the core is moved in a direction to close the main switch. So long as the current-flow is uninterrupted the main switch will be maintained in its closed position; but should the current be interrupted the switch will automatically resume its normal open position. The current passing through wire 9 originally branched so as to pass through the auxiliary contact associated with the main switch D, as well as through the auxiliary contact of the main switch A, but served no useful purpose, passing simply through resistance T the primary of the transformerf, to ground. As soon, however, as the main switch D is closed the auxiliary switch associated therewith is opened and no further flow of current can take place through the transformer f. If the trolley T is now moved toward and upon section 2, the direct current to coil D is interrupted and switch D opens. The alternating current which tends to energize this coil is so checked by the reactance R that there is not a suflicient flow to actuate the core 10.- Switch D therefore remains open and its auxiliary switch is closed. The current branches as before and passes through these auxiliary contacts (Z and CF, resistance r primary of transformer f, to ground. The secondary of transformer f is thereupon energized and current flows therefrom through one side of switch S, through coil A, to ground, completing the circuit through the secondary of the transformer which has one terminal grounded. The action of the coil A upon the core 12 and the lever mechanism 13, connecting this core to this stem at, closes the main contacts of switch A and opens the auxiliary contacts. It is noted that as soon as one main switch is closed the actuating-circuit for the other switch is broken, so that both switches cannot be closed at the same time. I

By the foregoing arrangement a simple and compact switch mechanism is providedv which is automatic and certain in its action and which obviates the necessity for a long dead section of trolley-wire or third rail or of bringing the car to a stop when it becomes necessary to operate the switches.

"particular form illustrated.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In combination, a supply-conductor, a pair of normally open switches, electromagnetic actuating means for said switches normally connected to said supply-cond uctor and arranged to actuate said switches selectively according as the current supplied is alternat 'ing or direct, and means associated with one of said switches for controlling the other.

2. In combination, a supply-conductor, a pair of main switches, electromagnetic actuating means for said switches normally connected to said supply-conductor and arranged to actuate said switches selectively according as the current supplied is alternating or direct, and an auxiliary switch associated with each of said main switches for controlling the actuating-circuit of the other main switch.

3. In combination, a supply-conductor, a pair of normally open switches, electromagnetic actuating means for said switches normally connected to said supply-conductor and arranged to actuate said switches selectively according as the current supplied is direct or alternating, and an interlock between the said switches for preventing the closing of one switch when the other is closed.

4:. In combination, a supply-conductor, a pair of switches, an electromagnet associated with each of said switches for controlling its operation, a connection including a reactance between one of said electromagnets and said supply-conductor, and a connection including a transformer between the other of said switches and said supply-conductor, whereby the switches are actuated selectively according as the current supplied is alternating or direct.

5 In combination, a supply-conductor, a pair of switches, an electromagnet associated with each of said switches for controlling its action, a connection including a reactance between one of said electromagnets and said supply-conductor, a connection including a transformer between the other of said electromagnets and said supply-conductor, .and auxiliary contacts controlled by each switch and arranged in the connection of the controlling-magnet of the other switch.

6. In combination, a supply conductor,

electric apparatus adapted to be-connected to said supply-conductor, a pair of switches for connecting said apparatus to said supply-conductor, means for selectively actuating said switches according as the current supplied is direct or alternating, and means associated with each switch for controlling the other switch.

7 In combination, a supply conductor, electric apparatus, a pair of switches for connecting said apparatus to said supply-conductor, an electromagnet associated with each of said switches for controlling its operation, a connection including a reactance between one of said electromagnets and said supply-conductor, and a connection including a transformer betweenthe other of said switches and supply-conductors whereby the switches are actuated selectively according as the current supplied is alternating or direct.

In witness whereof I have hereunto set my hand this 24th day of February, 1905.

JESSE S. PEVEAR. Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

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