US1976657A - Electric light fixture - Google Patents

Description

ct. Q, 1934. a3 (:QLE 1,976,657'

ELECTRIC LIGHT FIXTURE Filed Jan. 12. 1952 Fig l.

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' o Pl @hurles Cola MVW M re; 1934' UNITED STA ES PATENT OFFlCE' I I 'I 1' 1,916,051 -m.sc'rmc ucn'rnxrm to Wheeler a corporation of I application Janus-I112, 1932,

Cole, South Weymouth,

Mast, asslgnor Deflector Company, Boston, Mass,

usette Serial No. 588,1o9

2 claims (CL 113-458) Thisinvention relates to electric light fixtures and has for its object to provide an improved electric light fixture which has the various novel features that will be more fully hereinafter set forth and then pointed out in the appended claims; 1

.' In the drawing wherein I have illustrated a selected embodiment of my invention, Fig. 1 is a vertical sectional view through an electric light fixture embodying my invention;

Fig. 2 is a section on the line 2-2, Fig. 1;,

The electric light fixture herein shown. is of the type which is more or less commonly used for street lighting purposes and it comprises a socket member. 1 adapted to receive the electric light socket'member is detachably secured and which carries the wiring terminals and a metal canopy 4 that encloses the upper end of the porcelain body 3 and from which the latter is supported, said metal canopy 4 being carried at the end of a supporting pipe 5.

The detachable connection between the socket member 1 and the porcelain body 3 is of that familiar typewhich permits the socket member to or connected to the porcelain member. porcelain body 3 is, provided withatwo spring contact members bayonet members I that are secured to the socket member 1. I

The socket member is retained in its operative position by the frictional engagement of the con- 35 tact members Bwith the arms I. These arms are shown as bulged outwardly slightly at 8 so that when the arms '1 have been inserted between the contact members 6' sufllciently to carry the bulged the arms 8 will provide sufficient frictional engagement with the bayonet members to hold the socket member in place. I y

. The two contact members 6 are electrically connected with the wiring terminals 9 to which the circuit wires 10 are secured. The two arms 'I are connected to the two lamp terminals of the socket, to wit, the screw shell terminal 11 and the center terminal 12. The upper ends of said arms '1 are normally insulated from each other by means of insulating material 13 which is conflned'between the arms. when the lamp bulb 2 is in place'its screw terminal 14 and center terminal 15 engage the screw shell terminal 11 and center terminal 12 of the socket as usual.

55 Electric light fixtures of this type are commonbulb 2, a porcelain body member a to which. the

6 a ap or v between them twoarms "the wire terminals 9, contacts 6, arms 1 and terconstruction which ly used for street-lighting where a plurality of lights are connected in series and each socket member is constructed so that when any lamp 2 is removed the circuit will be automatically closed through the socket so as not to interfere with the go operations of the other lights of the series.

The center contact 12 of the socket has an angular-shaped stem or extension 16 which is acted on by a spring 1'! that normally tends to move said contact outwardly thereby to seat the porg5 tion 18 of the extension against the flange portion 20 of the screw shell 11.

Thespring 17 is retained in position by being confined in a spring-receiving recess 21 formed in the socket member and the stem 16 is formed 79 g 12 will be forced hackwardly against the action of the spring 17 into the position shown in Fig. 1. In, this position the portion 18 of the stem is separated from the flange 20 of the screw shellterininal and the circuit through the lamp is through minals 11 and 12 or the socket and 14 and 15 of the lamp. when, however, a lamp 2 is removed the expanding action of the spring 1'! seats the portion 18 of the stem 16 against the flange 20 of the screw shell 11 thereby closing the circuit so that there will be no interruption of current to the other lights of the series.

The parts thus far described are such as are more or less common in street-lighting lampiixtures and form no part of my present invention.

One feature of the invention relates to a novel is intended to obviate any danger that the center contacts of the lamp and the socket will become welded together when anylamp blows out. In this type of street lighting main line generally carries a voltage equal to the combined voltage of all the lamps of the series which are connected in series. If any one of these lamps should burn out, as sometimes happens, there is momentarily set up a heavy load on the particular socket containing the burntout lamp just before the film cut out or fuse 13 blows out and allows the circuit to close and thus continue its normal operation. During this brief period of heavy load there is apt to be an 110 contact between the two center terminals 15 and 2 6, arcing between the center contact 15 of the lamp vantage 01' this emstruction is that it provides a base and the center contact 12 of the socket socket which be which produces a sun lciently high temperature to weld together these two center contacts.

In order-to: avoid this I center contact current.

} as of a size nearly equalto the center terminal 15 of the lamp. This center terminal 12 of the socket is made of sui flciently heavy gauge metal so that'it will have the requisite strength notwithstanding the pro- Vision 01' the central aperture 25. -With this construction therewill ,pair of pliers especially made for this purpose.

beanannular 'closed at one end and also having ceiving chamber arcing to such an extent that closed end oi the socket member and minimum-,- screw shell terminal in the terminal-receiving chamber adapted to engage the screw a lamp base, an annular movable center also situated in said terminal-receiving chamber and adapted to engage the center 0! a lamp base, said center terminal having a portion overlying a portion of the shell te v in said spring-receiving chamber forming a resilient backing for the movable center terminal, said socket beingof generous thickness at its closed end to provide added and the walls of the socket member at the open end thinner at the open end than in'the body thereoi, whereby any crack which may develop in the edge oi said member at the, open end will tend to revert to said edge.

2. An electric light fixture comprising a cupshaped socket member of having a terminal-receiving Another feature or the construction relates to the shape 01' the socket shell 1. This shell is made of insulating material as usual shell terminal being 1 1 against the action ofsaid spring which is screwed into the screw shell terminal.

furnishing added strength.

The screw shell 1 is also made of extra length so that the open end 29 extends some distance below any parts which carry current.

In the operation of removing these socket I members a lineman frequently uses a pulleror a of smaller dimensions than said terminal or terminal-receiving chamber, a

m mibyalampbase'

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