US2063090A - Electric lamp and mounting therefor - Google Patents

Description

Dec. 8, 1936. w. J. GEIGER ET AL 2,063,090

ELECTRIC LAMP AND MOUNTING THEREFOR Filed April 6, 1955 [ATE/ENTER 5 WI, TEE. JG IEER 3-7 AL FREE 7? GASKYLL THEIF; ATTQRNEY Patented Dec. 8, 1936 UNITED STATES ELECTRIC LAMP AND MOUNTING THEREFOR Walter J. Geiger, Cleveland Heights, and Alfred T. Gaskill, Cleveland, Ohio, assignors to General Electric Company, a corporation of New York Application April 6, 1933, Serial No. 664,748

4 Claims.

Our invention relates to mountings for electric lamps and the like, and is especially adaptable and useful in cases where the light source should occupy a definite position with reference to some associated part or structure, such as a reflector or a lens. The invention is of particular advantage for projection lamps such as vehicle headlamps, in which an incandescent filament lamp is mounted in a reflector such as the well-known paraboloid reflector.

In headlamps as at present constructed, the lamp is mounted by inserting its bayonet base in a tubular bayonet socket which is itself mounted in an opening at the apex of the reflector, with suitable provisions for adjusting the socket relative to the reflector to focus the light source of the lamp to exactly the right position for any desired'distribution of light. While this arrangement permits easy removal and replacement of a lamp as Well as accurate focusing, yet it is mechanically complicated, and often liable to derangements which allow the lamp to shift out of focus.

To overcome these disadvantages of present practice, we prefer to mount the lamp base more directly on the reflector, without the intervention of a socket and adjusting means therefor. This We do in such a way that when a given lamp is once properly focused in a reflector, this adjustment becomes permanently fixed; although the particular lamp can still be removed and replaced as often as desired,-for cleaning of the lamp or its reflector, etc. In this way, we are able to dispense with the usual lamp socket, as well as with its focusing mechanism.

For removably mounting the lamp, we provide its base with engagement means adapted to engage in perfectly definite relation with an accurately located and fixed part or engagement means of the reflector, provision being also made for holding these parts in proper engagement. This requires of course that the engagement means on the base be properly adjusted and fixed relative to the light source; and while this may be accomplished by extreme accuracy in the basing of the lamp, yet we prefer to embody the engagement means of the base in a separate part or adapter that can be properly adjusted on the base in focusing and permanently fixed thereto,--as by soldering, or other methods of forming a fused joint. The lamp I-or, more properly speaking, its base with the properly focused adapter thereon-is inserted in an opening in the apex of the reflector, and the adapter is held properly engaged with the reflector by novel spring actuated means associated with the latter. Further features and advantages of our invention will appear from the following description of species thereof and from the drawing.

end of said base.

In the drawing, Fig. 1 is a partially sectioned elevation of a headlamp employing a form of mounting comprising our invention; Fig. 2 is a disassembled perspective'view of the mounting and lamp; Fig. 3 is a side view in section of electrical connection means for the lamp; Fig. 4 is a side view of a modified form of adapter; and Fig. 5 is a plan View thereof. 4

Referring to Figs. 1 and 2, the lamp, indicated generally by the numeral ID, comprises a bulb II having a filament I2 sealed therein and mounted on leading-in wires I3. A base l4 comprising a tubular shell I4 is mounted on said bulb I I, and carries a terminal pin I5 mounted in insulating material I6 and protruding rearward beyond the One of the leading-in wires I3 is connected to the base shell I4 and the other is connected to the pin I5. On the base I4 is mounted an adapter II. This adapter II has an enlarged tubular portion I8 which fits in a hole I9 in a flattened portion 20 at the apex of the reflector H. The enlarged portion I8 tapers down rearward to a comparatively narrow tubular portion 22, which surrounds the base I4. A flange 23 is formed at the forward end of the portion I8, adjacent the lamp Ill, for determining the longitudinal and axial position of the lamp in the reflector opening. The adapter II has engagement means for locking the lamp I0 against turning in the reflector opening (as hereinafter described), such as a rearwardly projecting lug 24 on the rim of said flange. The adapter II is located on the base 54 so that the rear surface of the flange 23 bears a definite relation to the filament I2, the reduced adapter portion 22 being of slightly larger diameter than the base, so that the lamp may be rocked in the adapter to locate the filament both axially and longitudinally, and may also be turned to locate it angularly with reference to the lug 2d. When the filament I2 has been thus prefocused, the adapter I! is fixed to the'shell I4, preferably by solder 25.

The lamp Ill is placed in the reflector 2i so that the rear surface or shoulder of the flange 23 bears against the inside surface of the flattened portion 20, which is definitely located with respect to the focal point of the reflector, and the lug 24 enters a seat formed by a recess or opening 26 in said reflector-thus definitely locating the filament to give the desired distribution of light. The flange 23 is held against the reflector by spring-actuated retaining means, hereinafter described, which engage an annular retaining lip 21 on the rear end portion 22 of the adapter II. The retaining lip 27! is beveled at its rear surface, and presents a square shoulder forward, toward the bulb. It is no larger, at least, than the portion l8, which may fit the opening l9 easily but without play.

' The spring-actuated retaining means for engaging the adapter shoulder at 21 are distributed around the lamp base opening IQ of the reflector 2|, and in the present instance have the character of independent spring catches embodiedin a spring holder 28 mounted on the rear of the reflector portion 20. The spring holder 28 comprises a flat annular portion 29 with a hole 30 therein of substantially the same diameter as the hole IS in the reflector 2|. This holder 28 is held on the reflector by a pair of oppositely located lugs or tongues 3| which engage in holes 32 in said reflector. A plurality of retroverted or bowed spring fingers 33 (three being shown) extend outward, rearward, and inward again from the periphery of the portion 29, and have rearward bent latch tips 34 at their ends. These tips 34 of the spring catches 33 coact with the rear bevel on the annular lip 21 of the adapter H, as well as with its front shoulder; i.. e., when the catches 33 snap over the lip 21 and engage be-- hind its shoulder they are held there, besides holding the lamp base |4 pressed home in the reflector opening IS, with the flange 23 firmly against the flattened portion 20 of the reflector all around the opening IS. A slot 35 is provided in the rim of the holder portion 29 corresponding to the opening 26 in the reflector, to accommodate the lug 24. The lug 24 not only looks the lamp In in proper angular relation to the reflector 2|, but also makes it virtually impossible to secure the lamp in any wrong angular relation, because of the impossibility of engaging the spring catches 33 2hinder the lip 21 unless the lug 24 is seated at Obviously the insertion-limiting shoulder or flange of the adapter need not be continuous as in Fi 2; on the contrary, it may be interrupted even to the extent shown in Figs. 4 and 5, where three properly distributed arms 'or lugs 36-3|38 are substituted for the flange 23, an anti-turning key lug 39 similar to lug 24 being provided on lug 36. It may be preferable to employ such lugs in view of the fact that a solid flange is liable to warp. v

Electrical connection may be made to the lamp III by a helical spring connector 40 (Fig. 3) which is slipped over the pin l5 of the lamp. Said connector 40 comprises a helical spring 4|, one end of which is clamped on a metal sleeve 42 mounted on the end of the insulating covering 43 of a stranded conductor 44 which is in contact with said sleeve. The spring 4| is deformed so that the axis thereof is not a straight line. In the preferred form a number of turns 45 at the opposite end of said spring 4| are offset axially with respect to the remaining turns, thus insuring a firm contact of said spring with the pin I5 which brings the axis of the spring back to a straight line. An insulating covering 46, preferably a soft rubber tube, surrounds the said spring 4|.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. The combination of a reflector having a lamp base opening therein, with a lamp comprising a bulb and a base having a portion of substantially the same diameter as said opening with a lateral projection thereon forming an external shoulder seating directly in said reflector opening, said lateral projection engaging one side of the margin around the said opening in said reflector, another external shoulder on said base on the opposite side of said reflector, and a spring disposed between said reflector and said second mentioned shoulder and exerting a pressure axially oi the lamp to hold said lateral projection against said reflector margin.

2. The combination of a reflector having a lamp base opening therein, with a lamp comprising a bulb and a base having a portion of substantially the same diameter as said opening with a lateral projection thereon adjacent said bulb forming an external shoulder seating directly in said reflector opening, said lateral projection engaging the inside of the margin around the said openingin said reflector, another external shoulder on said base behind said reflector, and a spring disposed between the back of said reflector and said second mentioned shoulder and exerting a pressure rearwardly of the lamp to hold said lateral projection against said reflector margin.

3. The combination of a reflector having a lamp base opening therein, with a lamp comprising a bulb and a base having an enlarged portion of substantially the same diameter as saidopening with a lateral projection thereon adjacent said bulb forming an external shoulder seating directly in said reflector opening, said lateral projection engaging the inside of the margin around the said opening in said reflector, another external shoulder on said base behind said reflector not exceeding the said enlarged portion in size, and a spring disposed between the back of said reflector and said second mentioned shoulder and exerting a pressure rearwardly of the lamp to hold said lateral projection against said reflector.

4. An electric lamp comprising a bulb and a base and an adapter fixed on said base in focus adjustment, said adapter consisting of a metal shell comprising an enlarged cylindrical portion at one end with a lateral' projection on one end thereof forming an external seating shoulder, a reduced cylindrical portion adjacent the opposite end of said enlarged portion surrounding said base'and secured thereto, and an outwardly beveled lip at the end of the said reduced portion of said adapter constituting a shoulder facing said first mentioned shoulder and not exceeding said enlarged portion of said adapter in size.

WALTER J. GEIGER. ALFRED 'r. GASKILL.

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