US399748A - Incandescent-electric-lamp socket - Google Patents

Description

(No Model.)

G. E. EGAN.

INGANDBSOBNT ELECTRIC LAMP SOCKET. No. 399,748. Patented Mar. 19 1889.

WITNESSES, IJV V'EJV'TOR A141, .dttorney UNITE TATES PATIE T rrIcE.

CHARLES E. EeAN, or COLUMBUS, oI-IIo, ASSIGNOR or ONE-TENTH TO N. w. HALLEY, or TIPTON, INDIANA.

INCANDESCENT-ELECTRlC -LAMP SOCKET.

SPECIFICATION forming part of Letters Patent No. 399,748, dated March 19, 1889.

Application filed July 11, 1888. Serial N0- 7 -l T0 aZZ whom it may concern:

Be it known that I, CHARLES E. EGAN, a citizen of the United States, residing at O0- lumbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Incandescent Electric Lamps; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

My invention relates to incandescent electric lamps, and has for its object the production of a lamp which will be cheaper to menu-- facture and will maintain a constant resistance in the lighting-circuit,whether the lamp is burning or extinguished.

Other objects of the invention are to dispense with the key or switch mechanism, which render the sockets of the lamps now on the market expensive, to provide for the automatic cutting in of a coil equal in resistance to the resistance of the lamp-filament, and to lengthen the life of the filaments. In lamps as commonly constructed the current is thrown into the filament by means of a switch or key, and mechanism is provided for establishing the circuit around the lamp when the filament is cut out. hen the lamp is extinguished, the resistance of its filament is subtracted from the whole resistance of the branch in which the lamp is located, and when a number of. lamps are cut out the aggregate variation in resistance becomes so considerable that automatic regulation of the current to correspond to the variable resistance of the consuming-circuit becomes necessary. One of the great difficulties in the application of chemical or galvanic generators of electricity to electric lighting finds its origin in this change of resistance. The current remaining constant when any considerable number of lamps are cut out, the resistance is so reduced that the remaining lamps are incapable of carrying the whole current, and they therefore burn at a degree of incandescence which soon destroys the filaments.

It is the object of my invention to overcome this difficulty by preserving the resistance of the consuming-circuit at an invariable quantity.

To these ends my invention consists of an 5 5 incandescent lamp in which the circuit through the filament may be made and broken and the lamp firmly secured in its socket by simply manipulating the body of the lamp, no key being used.

My invention also consists in cutting in a resistance equal to the resistance of the filament by the mere act of extinguishing the lamp.

The invention also embodies certain structural features which will hereinafter be described in this specification, and then definitely indicated in the appended claims.

In the accompanying drawings, which illustrate my invention, Figure 1 is a side eleva tion of an incandescent lamp made in accordance with my improvements. Fig. 2 is a side elevation, the socket being shown in section on a larger scale than Fig. 1. Fig. 3 is a plan view of the contact-springs for shifting the current and maintaining the lamp in the socket.

Reference being had to the drawings, 1 is the bulb of a lamp of which the stem 2 fits a contracted portion of a socket or casing, This casing is provided with a series of slots through which screws 12 pass into an insulating-support of vulcanized fiber. The base of the lamp, which is provided with a threaded opening to facilitate attachment to a bracket, 8 5

is secured to the insulating-support by the same screws and in the same manner as the casing On the insulating-support 4 are se-' cured four metallic springs, 5 6 13 14:, which are of such a height that their bent terminals will engage headed pins 7 S, projecting from the stem of the lamp, as shown in Fig. 2. These springs, when free to act, approach each other diametrically, so that they lie closer than the distance between the heads of the pins 7 8. The free ends of the springs are bent at right angles to the main portions and lie in a position transverse to the length of the socket. These ends are made flaring and are provided with a circular recess and bev- IOO eled sides, as shown in Fig. 3, so that when the lamp is turned in its socket the stems of the pins 7 8 may be forced between springs 5 and 6 or 13 and 14, in which position the springs will engage the pins with an elastic pressure and the lamp will be firmly held in the socket. Between the springs 5 and 6 metallic posts 9 and 10 are secured to the insulating-base 4. These posts are provided at their free ends with adj ustingscrews or other devices, as shown in Fig. 2, so that contact can be made with springs 5 and 6 when the lamp is removed from the socket. These posts are in electric connection with the resistance-coil 11, having a resistance equal to that of the lampfilament. The springs 5 and 6 are electrically connected with thesupply-circuit, while the springs 13 and 14 are not in circuit at all.

The operation will now be understood. When the lamp is placed in circuit, the socket is removed and the adjusting-screws are set so that contact will be made with the springs 5 and 6. The stem is then inserted in the socket and the pins 7 and 8 forced into engagement with either pair of springs. When the pins are engaged by springs 13 and 14, springs 5 and 6 are forced by their resiliency into electric contact with the adj usting-screws on the posts 10 and 11, and the circuit passes through the flexible conductors, springs 5 and 6, contacts on posts 9 and 10, and the resistance-coil. If now it be desired to light the lamp, the bulb is grasped by the hand and given a quarter-turn, which brings the pins 7 and 8 into contact with springs 5 and 6, forcing the springs apart and rupturing their connection with the adjusting devices on posts 9 and 10. This ruptures the circuit through the resistance-coil and throws the current through the lamp-filament. It will thus be seen that a key is entirely dispensed with, yet the same result is accomplished with equal or greater efficiency. It will also be seen that whether the lamp is burning or extinguished the same resistance will be interposed in the consuming-circuit.

A very important incident flowing from the structure above described is that in manipulating the lamp the headed pins which form the terminals of the filament will be frequently changed in lighting or extinguishing a lamp-that is to say, the filament-terminals will reverse position with reference to the supply-conductors, so that the current will pass through the filament in reverse directions from time to time. It is well known that the life of the filaments is shortened by reason of the wear at the positive side, due to an apparent translation of the particles of carbon with the current toward the negative terminal. This unevenness of wear produces a weak point in the filament, which cracks and destroys the usefulness of the entire lamp. l/Vith my lamp, however, the wear may be rendered absolutely even by always turning the lamp in the same direction, a practice a consumer will be sure to follow when he learns that it will cheapen the cost of his light. In this way the lamp itself is made to serve as a current-reverser or polechanger for the current which passes through the filaments.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s-

1. In an incandescent electric lamp, the combination of a socket adapted to fit over the stem of the lamp, spring-jaws provided with gripping-faces within the socket in permanent electrical connection with the opposite sides of the supply-circuit, and metallic projections on its stem in electrical connection with the filament adapted to be engaged by the jaws and hold the lamp firmly in the socket, whereby the lamp may be lighted or extinguished by rotating the globe.

2. In an incandescent electric lamp, the

combination of a socket adapted to fit over the stem of the lamp, two or more pairs of diametrically-opposite sprin g-jaws within the socket, metallic projections on the stem in electrical connection with the filament adapted to be engaged by either pair of jaws, and conductors leading from one pair of jaws to the outside of the socket, whereby when the lamp is in a supply-circuit it may be lighted or extinguished by partially rotating the bulb. I

3. In an incandescent electric lamp, the combination, with the socket, of two or more pairs of spring-jaws within the same, projections on the lamp-stem electrically connected with the filament adapted to be engaged by either pair of jaws, contacts in operative relation to one pair of v jaws and engaged by the same when the filament is out of circuit, and a resistance equal to the lamp-filament between the contacts, whereby thelamp may be extinguished by partially rotating its bulb and the resistance thrown into circuit.

4. In an incandescent electric lamp, the combination of a socket adapted to fit over the stem of the lamp, spring-jaws within the socket, and metallic projections on the stem electrically connected with the filament, said jaws being provided with gripping-faces adapted to engage the projections when the lampglobe is turned in either direction, whereby the lamp may be secured firmly in its socket, lighted or extinguished, and the current through the filament reversed by simply turning the globe, as and for the purpose set forth.

In testimony whereof I afiix my signature in presence of two witnesses.

CHARLES E. EGAN.

Witnesses:

M. P. CALLAN, II. C. WISE.

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