US439392A - Thomas a - Google Patents

Description

(No Model.)

T. A. EDISON.

ELEGTRIG LIGHTING SYSTEM.

P19439392. Patented Oct. 28, 1890.

UNITED STATES PATENT OFFICE.

THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.

ELECTRIC-LIGHTING SYSTEM.

SPECIFICATION forming part of Letters Patent No. 439,392, dated October 28, 1890.

Application filed August 22, 1882. Serial No. 69,995. (No model.) Patented in England March 3, 1882, No. 1,023.

To all whom it may concern:

Be it known that I, THOMAS A. EDISON, of Menlo Park, in the county of Middlesex and State of New Jersey, have invented a new and useful Improvement in Electric-Lighting Systems, (Case No. 473,) of which the following is a specification.

Said invention is patented in Great Britain by Letters Patent No. 1,023, dated March 3, 1882.

The object I have in View is to produce means to be used in connection with dynamo or magneto-electric machines supplying electric lamps or other translating devices arranged in multiple are, which means will prevent injury to the machine or machines when an abnormally large current is caused to flow by the addition of more lamps or other translating device than the plant has capacity to furnish, and will at the same time notify the engineer of the condition of affairs. This object I accomplish in the following manner: A piece of safetycatch wire or material is placed in one of the conductors of the main or consumption circuit. This safety-catch is of such size and character that when more lamps are put in circuit than the plant is designed to furnish, and before the machine or machines are injured by the abnormally-large flow of curren it will burn out and break the circuit between the generator and the transflating devices. In a shunt around this safetycatch are arranged a vibrating bell and a resistance, the resistance being suificient to prevent the striking of the bell when the safety-catch is intact; but when the safetycatch is burned out the current passes through the bell-circuit and operates the bell-hammer. The lights at the same time Will drop to a red heat. The engineer then removes a sufficient number of lamps and replaces the safety-catch. The foregoing will be better understood by reference to the drawing, in which the figure is a diagrammatic view of the parts.

A represents adynamo or magneto-electric machine; 1 2, the main or consumption circuit, and a a incandescing electric lamps or other translating devices located in multipleare or derived circuits.

The field-circuit of the machine may be a multiple-arc circuit 3 4 from 1 2, and be provided with an adjustable resistance R.

B is a piece of safety-catch wire or material placed in 1 or 2 between the lamps and the machine A. In a shunt 5 or 6, around B, are arranged a resistance R and a vibrating bell composed of electro-magnet h, spring '5, bell-hammer 7c, and gong l.

WVhat I claim is- 1. The combination of one or more electrical generators and translating devices supplied therefrom, of a safety-catch for preventing injury to said generator or generators when their capacity is exceeded and an alarm adapted to give notice of the destruction of said safety-catch, substantially as set forth.

2. The combination, with the safety-catch between the translating devices and the generator, of an alarm arranged in a shunt-circuit around said safety-catch, substantially as and for the purpose set forth.

This specification signed and witnessed this 12th day of August, 1882.

THOMAS A. EDISON.

Witnesses:

H. W. SEELY, E. H. PYATT.

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