US476700A

US476700A - Electric-arc lamp

Info

Publication number: US476700A
Authority: US
Publication date: 1892-06-07
Anticipated expiration: 1909-06-07

Description

(No Model.)

B. E. THURSTON.

ELECTRIC ARC LAMP.

No. 476,700. Patented June 7, 1892.

A TTOHNE Y8,

U NITED STATES PATENT OFFICE.

ROBERT H. THURSTON, OF ITHAOA, NEXV YORK.

ELECTRIC-ARC LAM F.

SPECIFICATION forming part of Letters Patent No. 476,700, dated June '7, 1892.

Application filed February 27, 1892. Serial No. 423,026. (No model.)

To all whom it may concern:

Be it known that 1, ROBERT H. THURSTON, of Ithaca, in the county of Tompkins and State of New York, have invented a new and useful Improvement in Arc Lamps, of which the following is a specification, reference being had to the annexed drawings, forming a part thereof, in which- Figure 1 is a side elevation of an arc lamp to which my improvement has been applied. Fig. 2 is a plan view of the carbons. Fig. 3 is a side elevation of the carbons, and Fig. 4 is an enlarged side elevation of the ends of the carbons.

In Figs. 2, 3, and 4 the angle made by the carbons with each other is exaggerated to clearly illustrate the positions of the carbons relative to each other.

Similar letters of reference indicate corresponding parts in all the views.

In the operation of the well-known form of electric lamp employing broad flat carbons much difliculty is experienced in Windy weather from the shaking of the carbons past one another and their jamming and welding together in that position, thus extinguishing the lamp.

The object of my invention is to obviate this difficulty, thus rendering the operation of the lamp reliable.

My invention consists in twisting one of the carbons so that its end will form a small an gle with the other carbon, thus preventing their passing.

In carrying out my invention I employ a lamp of any well-known construction,in which are used broad flat carbons, and I turn one of the carbons (preferably the lower one) so that the end will form a slight angle with the carbon with which it contactsthat is to say, I arrange the fixed carbon in a plane which forms a slight angle with the plane of the movable carbon, the said angle being only sufficient to prevent the movable carbon from passing the fixed one. In the drawings I have shown this angle greatly exaggerated to better illustrate the principle of my invention. The angle in practice is not so large as to make any material difference in the length of the are formed between the center and the ends of the carbons.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- An electric lamp having broad fiat carbons moving in the same vertical line or in approximately parallel lines, with the carbons arranged in planes intersecting at a smallangle for the purpose of preventing the carbons slipping by each other when shaken by the wind or other force, substantially as specified.

HARRIS J. RYAN, JOHN H. BARR.