US717071A - Electric switch. - Google Patents

Description

No. 7|7,07|,` Patnted Dec'. 3o, |902.l

w. M. Bnown. ELECTRIC SWITCH.v

(Application led Apr. 1B. 1902.)

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Patented Dec. 30, |902. W. M. BVRUWN.

ELECTRIC SWITCH.

(Application led Apr. 1B, 1902.)

(No llodel.)

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Param VILLIAM MILT. BROWN, OF JOI-INSTOWN, PENNSYLVANIA, ASSIGNOR 'IO THE LORAIN STEEL COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 717,071, dated December 30, 1902.

Application tiled April 18, 1902. Serial No. 103,514. (No model.)

T0 all wiz/0777, it ntcty concern:

Be it known that I, WILLIAM MILTON BROWN, of Johnstown, in the county of Oambria and Stateof Pennsylvania, have invented a new and useful Improvement in Electric Switches, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification.

My invention has relation to certain new and useful improvementsin electric switches, and more particularly to switches which are designed for use on electric cars which are operated by systems in which the motor-current is collected from an underground conductor through circuit-closing devices controlled by a magnet on the car. The coils of this magnet are energized in starting the car by a current from a battery or otherV source independent of the line-circuit. This independent current is used only until such time as the line-current is picked up. Its circuit is then opened, the continued energization of the magnet being maintained by the current in the line-circuit. In practice it may sometimes happen, owing to some defect in operation or some break in the circuit between the collecting shoe or trolley and the underground current-conductor, that the car may lose its current and the motorman will not be aware of the fact until it is brought to his attention by the slowing down of the car. It is then necessary for him to again close the batterycircuit through the magnet-coils until such time as the magnet has once more acted to close the line-circuit. During this time, however, the car may have come to a standstill or its speed may have been greatly reduced.

My invention is designed to provide a novel form of switch for connecting the battery or other independent source of current-supply with the magnet-coils and to provide such switch with means wherebyitwill at the same time notify the motorman of the fact.

With this and other hereinafter-described objects in view my invention consists in the combination, with a switch arranged to connect and disconnect a battery or other independent source of current-supply in circuit with the magnet-coils, or some of them, of a locking device arranged to normally hold said switch in open circuit position and released by failure of the line-current and means whereby when so released the switch will be automatically moved to circuitclosing position. Then the car is intentionally stopped for any reason, this switch will also of course operate in the manner described, and to prevent the battery-circuit from remaining closed while the car is stopped I provide the switch with a second open-circuit position, to which the switch will be automatically moved upon prolonged failure of the line-current. In this connection I also provide means for retarding the movement of the switch past its circuit-closing position to its second position of open-circuit.

My invention also consists in the novel construction and combination of parts, all as hereinafter described, and pointed out in the appended claims, reference being had to the accompanying drawings, in which- Figure l is a side elevation of a switch embodying my invention with the casing in vertical section; Fig. 2, a horizontal section on the line 2 2 of Fig. 1, and Fig. 3 a wiringdiagram showing the electrical connections for the switch.

Fig. 3 shows the invention applied to a system of the character described and claimed in my prior patents, Nos. 558,151 and 594,379, and the invention will be described in such connection. I desire it understood, however, that this is for the purposes of illustration only and that my improved switch may be used in connection with systems which differ widely from those of said patents, as will be evident from the following description.

Referring to the drawings, the numeral 1 designates a suitable casing or closure, and 2 a spindle journaled therein and having its upper projecting end provided with an operating-handle 3.

ft is an insulated contact carriedby the spindle 2, and 5 and 6 are two relatively fixed spring-contact fingers which are arranged to be bridged by the contact 4t when the latter is in its circuit-closing position. Fig. 2 shows said contact in full lines at one of its opencircuit positions, which is its normal running position, and in dotted lines at its other opencircuit position, which is its oif position. f

7 designates a spring which is connected to the spindle 2 and which acts upon it to vmove the contact 4 from its normal running position to its off position.

9 is a magnet whose coil is connected in the line-circuit and which is formed with polepieces 10. 11 is an arm carried by the spindle 2 and forming an armature for said magnet.

12 is an air dash-pot having a piston or plunger 13, which is connected to an arm 414 of the spindle 2.

15 and 16 are vent-openings in the plunger 13, the opening 16 being adj usted by a screwvalve 17, and 18 is a vent-opening in the cylinder of the dash-pot arranged to register with the opening 15.

Referring now to Fig. 3, 19 represents the dynamo at the power-station, one terminal of which is connected tothe rail 2O of the track or to some other suitable return-conductor, while the other terminal is connected to the normally open switching mechanism of the contact-boxes, one of which is shown at 21. 22 is the current-collecting shoe or trolley; 23, the usual overhead or canopy switch; 24, the usual controller; 26, the carbattery; 27, the motors; 28, the low-resistance coils of the magnet connected in series with the motors; 29, the high-resistance coils of said magnet connected in shunt to the motors, and 30 one of the car-wheels through which the return-circuit is made. The arrangement shown in this figure is in general substantially the same as shown in my said Patent No. 594,379, to which reference may be had for a further description. 31 designates the switch which constitutes the present invention, and the switch-contact together with the lock-magnet coil shown in this figure have the same reference-numerals as in Figs. 1 and 2. It will be seen that this switch 3l is placed in circuit between the battery 26 and the low-resistance coils 28 of the carmagnet and that the magnet-coil 9 is connected in series with the high-resistance coils 29 of said magnet, a circuit make-and-break switch 32 being also included in circuit with said coils. The coil 9 may, however, be connected in any other suitable way in the carcircuit.

In starting the car the motorman moves the handle 3 from its off position in a clockwise direction, and as soon as the contact 4 reaches a position to `bridge the contacts 5 and 6 the coils 28 are closed in the batterycircuit and the magnet is energized to operate the circuit-closing device in the contact-box 2l, over which the car is standing, and thus pick up the line-current. The motorman is obliged to move the handle 3 slowly past this circuit-closing position, byv reason of the resistance to movement offered by the dash-pot, until such time as its plunger has uncovered the vent-opening 18, thus insuring sufficient time for the line-current to act before the battery-circuit is opened. Continued movement of the handle 3 brings the armature 11 against the pole-pieces 10, and if the line-current has been picked up the coil 9 is at this time energized and the magnet will hold the switch at this position. If for any reason the line-current has not been picked up, the spring 7 will immediately return the contact 4 to circuit-closing position. When for any reason the line-current fails, the coil 9 is denergized and the spring at once returns the contact 4E to circuit-closing position. The corresponding movement of the handle 3 will notify the motorman of the failure of current and the action of the dashpot will hold the switch in this position long enough to restore the line-current and to give the motorman manual control of the switch. If the car is to be stopped after the period of retardation caused by the dash-pot, the switch will return to its od position.

I do not wish to limit myself to the exact construction and combination of parts which I have herein shown and described, as various changes may be made in the details thereof without departing from the spirit and scope of my invention.

While in Fig. 3 I have shown the invention as applied to a car apparently intended for normal travel in one direction only, :it is evident that the switch 31 and the connections therefor may be duplicated in a manner well known to those skilled in the art to enable the car to be operated from either end.

I do not claim, broadly, herein a switch arranged to automatically connect an independent source of current-supply with the magnet-coils when the current abnormally fails in the line-circuit, as such a switch is described and claimed in my Patent No. 599,828, of March 1, 1898.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is*

1. The herein described electric switch, having two open-circuit positions, and an intermediate circuit-closing position, an electromagnetically-controlled locking device for holding the switch in one of its open-circuit positions, andr means for retarding or prolonging the movement of said switch across its circuit-closing position.

2. The herein described electric switch, having two open-circuit positions and an intermediate circuit-closing position, a magnet arranged to normally lock said switch at one of its open-circuit positions, means for moving said switch from one open-circuit position to the other, and a device acting to retard the movement of said switch across its circuit-closing position.

3. The herein-described electric switch, consisting of relatively fixed contacts, a rotary member carrying a contact arranged, when the said member is in an intermediate position, to bridge the xed contacts, an electromagnetic lock for holding the said member to one side of its intermediate position, a

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spring for moving said member to the other side of said intermediate position when the lock is released, and a device arranged to retard the movement of said member across its intermediate position.

4. The herein described electric switch consisting of a pair of relatively xed contacts, a rotary spindle carrying a coperating bridging contact, an electromagnet, an arm connected to said spindle and forming an armature for said magnet, a spring for moving the spindlein one direction, a handle for moving it in the opposite direction, and a dashpot connected to the spindle and acting to retard a portion of its movement.

5. The combination with a car-magnet having two sets of en ergizing-coils, one set of said W. MILT. BROWN.

Witnesses:

L. OCONNELL, H. W. SMITH.

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