US2033699A - Electric projection lamp - Google Patents

Description

March 10, 1936. T. w. FRECH ELECTRIC PROJECTION LAMP Filed June 9, 1953 [NI/ENTER. T212701 0A5 WFREZH .575 AT TURKEY" Patented Mar. 10, 1936 UNITED STATES PATENT OFFICE ELECTRIC PROJECTION LAMP ration of New York Application June 9, 1933, Serial No. 675,025

14 Claims.

My invention relates to electric lamps and mountings therefor, 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 incandescentfilament 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 cylindrical base bearing bayonet pins in a tubular socket having bayonet slots 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 I prefer to secure the lamp base directly to the reflector instead of securing the lamp base to a socket and afterwards obtaining the proper adjustment by movement of the socket. This is done in such a way that when a given lamp is oncesecured to a reflector, it is permanently and accurately located and further adjustment is unnecessary. The particular lamp can still be removed and replaced as often as desired,--for cleaning of the lamp or its reflector, etc.

For removably mounting the lamp, its base is provided with means adapted to engage in a perfectly definite and fixed relation with an accurately located and fixed part or engagement means of the reflector, provision being also made for holding said base and reflector engagement means in proper engagement, preferably by spring pressure. This requires, of course, that the engagement means on the base be properly adjusted and fixed relatively to the light source; and while this may be accomplished by extreme accuracy in the basing of the lamp, yet I prefer to embody the engagement means of the base in a separate part'or adapter that can be properly adjusted on the base and permanently fixed thereto,-as by soldering, or other methods of forming a fused joint. For bringing the securing means of base and reflector into proper relation to be held engaged by spring pressure, axial and rotary movement of the lamp relatively to the reflector is preferred. Further features and advantages of my invention will appear from the following description of species thereof, and from the drawing.

In the drawing, Fig. l is an elevation, in section, of a headlamp constructed according to my invention; andFig. 2 is a disassembled perspective view of the various parts thereof; Fig. 3 is a partial vertical section on an enlarged scale of the assembly shown in Fig. l.

. Referring to the drawing, the lamp com- 1( prises a bulb I i having a filament l2 sealed therein and mounted on leading-in wires B. A base H comprising a tubular shell i5 is mounted on said bulb I I and carries a terminal pin l6 mounted in insulating material I! and protruding beyond the end of said base. One of the leading-in wires I3 is connected to the pin l6 and the other is connected to the shell 15. An adapter I8 com prising a narrow band or shell 19 having a transversely extending projection or flange 20 at one 2 end thereof is mounted on the base shell I5. The adapter [8 is located on the base ll so that the flange 20 (or the back surface thereof), bears a definite relation to the filament II, the shell [9 of said adapter being of slightly larger diameter than the shell l5 so that the lamp base may be rockedand shifted therein to locate the filament along the axis of the flange and transversely thereto. The band IQ of the adapter may of course be omitted and the flange 20 used alone so as a ring, or the said flange may be incorporated in the base shell l5 itself. A plurality of lugs or wings may also be substituted for the continuous flange 20. A plurality of openings preferably bayonet slots 2i (three being illustrated) are 3: formed in the flange 20 and are preferably unequally spaced. Each of said slots 2! comprises an enlarged circular portion 22 at one end adapted to slip over the head 23 of a cooperating pin 24 resiliently mounted on the reflector 25, and a a smaller circular portion 26 at the other end adapted to engage a portion of the head of said pin 24. The said slots 2| may be termed arcuate in the sense that they permit a rotary movement of the lamp during the mounting operation and 4. bayonet in the sense that they cooperate with the pins 24 in the mounting and positioning of the lamp. It will be obvious that the afore-described construction provides openings, which allow the flange to clear the pin heads, and cam edges on the 5- flange which, after the portions 22 having the greatest clearance are slipped over the heads of the pins 24 and the lamp rotated, cause the said pins to be first advanced and then allow them to be retracted by the spring 3| to settle in the seat- 5 ing portions 26 each of which has a. predetermined angular relation to the filament.

The reflector comprises a flattened or plane portion 21 at the apex thereof having an opening 28 therein to permit insertion of the lamp base It, the front or inner surface of said flattened portion 2! bearing a definite relation to the focal point. The pins 24 are mounted in holes 29 at the margin of hole 28 in the flattened portion 2! of the reflector and extend through holes in a ring-shaped spring member 3|, being resiliently held against the reflector thereby. The rear ends'32 of the pins 24 are pinched and flattened to hold the spring member 3| in place through the intervention of washers 33., The ring-shaped spring member 3| has a plurality of V-shaped indentations or protuberances 34 therein, preferably three, one being located between each of the holes 30. The said indentations 34 bear against the back of the flattened portion 21 of the reflector and thus impart a spring efiect to the intermediate portions of the ring 3| when the heads of the pins 24 are pulled forward by the flange 20 of the lamp, as hereinafter explained. The spring member 3| may, of course, take other shapes or forms, or each of the pins 24 may carry a separate spring, such as a helical wire spring.

To mount the lamp Ill, the base i4 is inserted in the opening 28 of the reflector until flange 20 engages the flattened portion 21 of the reflector, the circular portions 22 of slots 2I-belng slipped over the heads 23 of pins'24. The back surfaces -of the heads 23 of pins 24 are'made conical in shape so that when the lamp ill isxnow rotated clockwise, the said surfaces 35 will ride up on the narrowing portions of slots 2|, through the restricted portions 36, and settle into the circular portions 26, being held firmly therein by the spring member 3|. It will be obvious that the angular positions of the portions 26 predetermine the angular position of the filament |2. It will be obvious, also, that the use of unequally spaced slots to correspond with the unequally spaced retaining pins, hereinbefore referred to, insures the proper insertion of the lamp.

It is apparent from the drawing that this construction provides a very compact, sturdy "and eflicient means of accurately mounting a lamp.

Electrical connection is made to the terminal pin 6 by any suitable means, such as a connector comprising a helical coil of wire adapted to be slipped over said pin and having a number of turns offset so as to provide a firm contact with said pin. Such a connector is disclosed in U. S. patent application, Serial No. 663,357, Geiger, filed March 29, 1933.

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

1. Thecombination of a lamp comprising a bulb having a light source therein and a base having a transversely extending projection accurately located with respect to said light source, and a reflector having a spring actuated pin mounted thereon, said lamp projection having an arcuate slot therein for engaging said pin to lock said lamp against said reflector upon arotary movement of said lamp.

2. The combination of a lamp comprising a bulb having a light source therein and a base having a transversely extending flange accu-- rately located with respect to said light source, and a reflector having a spring actuated pin mounted thereon, said lamp flange having an arcuate slot therein for engaging said pin to lock said lamp against said reflector upon a rotary movement of said lamp.

3. The combination of a lamp comprising a bulb having a light source therein and a base having a transversely extending flange accurate ly located with respect to said light source, and a. reflector having a plurality of spring actuated pins mounted thereon, said lamp flange having a plurality of arcuate slots therein for engaging said pins to lock said lamp against said reflector upon a rotary movement of said lamp.

4. The combination of a lamp comprising a bulb having a light source therein and a base having a transversely extending projection accurately located with respect to said light source, a reflector having a pin mounted thereon, and spring means mounted on said reflector and engaging said pin, said lamp projection having an arcuate slot therein for engaging said pin to lock said lamp against said reflector upon a rotary movement of said lamp.

5. The combination of a lamp comprising a bulb having a light source therein and a base having a transversely extending projection accurately located with respectto' said light source, a reflector having a pin mounted thereon, and spring means mounted on said reflector and engaging said pin, said pin comprising a head the back of which is conical in shape, and said lamp projection having a slot therein for' engaging said conical portion of said pin head to lock said iamp in said reflector.

, a reflector having a pin mounted thereon, and

spring means mounted on said reflector and engaging said pin, said pin comprising a head portion located at the inside of said reflector, the back of said pin head being conical in shape, and said lamp projection having an elongated slot therein adapted to slip over said pin head and allow rotation of said lamp until said conical portion of said pin head seats in a portion of said slot to lock said lamp in said reflector.

7. The combination of a lamp comprising a bulb having a light source therein and a base having a transversely extending flange accurately located with respect to said light source and having a plurality of arcuate cam engagement surfaces therein, and a reflector having a lamp base opening therein and a plurality of spring actuated pins disposed around the margin of said lamp base opening and having head portions the backs of which engage said arcuate cam means in said lamp base flange to press said flange against said reflector upon a rotary movement of said lamp.

8. The combination of a lamp comprising a bulb having a light source therein and a base having a transversely extending flange accurately located with respect to said light source and hav- -ing a plurality of arcuate slots therein, and a reflector having a lamp base opening therein and a plurality of spring actuated pins disposed around the margin of said lamp base opening and having head portions the backs of which engage said arcuate slots in said lamp base flange to press said flange against said reflector upon a rotary movement of said lamp.

9. The combination of a lamp comprising a bulb having a light source therein and a base having a transversely extending flange accurately located with respect to said light source and having a plurality of arcuate slots therein of varying width, and a reflector having a lamp base opening therein and a plurality of spring actuated pins disposed around the margin of said lamp. base opening and having head portions the backs of which are conical in shape and engage said arcuate slots in said lamp base flange to press said flange against said reflector upon a rotary movement of said lamp.

10. In an electric lamp for light beam projecting devices, the combination of a bulb, a base, a filament within said bulb, and a transversely extending flange accurately located on said base at a predetermined distance and in a predetermined plane with respect to said filament, and means for predetermining the angular position of said-filament when said lamp is mounted including a plurality of spaced bayonet slots in said flange, corresponding end portions of which have predetermined angular relations to said filament.

11. In an electric lamp for light beam projecting devices, the combination of a bulb, a base, a filament within said bulb, and a transversely extending flange accurately located on said base at a predetermined distance and in a predetermined plane with respect to said filament and means for predetermining the angular position of said filament when said lamp is mounted including a plurality of spaced bayonet slots in said flange, corresponding end portions of which have predetermined angular relations to said filament, each of said slots being larger at one end than at the other with an intermediate restricted portion.

12. In an electric lamp for light beam projecting devices, the combination of a bulb, a base, a filament within said bulb. and a transversely extending flange accurately located on said base at a predetermined distance and in a predetermined plane with respect to said filament, and having a plurality of asymetrically spaced bayonet-slots therein, corresponding end portions of which have predetermined angular relations to said filament.

13. In an electric lamp for light beam projecting devices, the combination of a bulb, a base, a filament within said bulb, and a transversely extending flange substantially entirely surrounding and accurately located on said base at a predetermined distance and in a predetermined plane with respect to said filament, and means for predetermining the angular position of said filament when said lamp is mounted including three spaced bayonet slots in said flange, corresponding end portions of which have predetermined angular relations to said filament.

14. In an electric lamp for light beam projecting devices, the combination of a bulb, a base, a filament within said bulb, and a transversely extending flange accurately located on said base at a predetermined distance and in a predetermined plane with respect to said filament, and means for predeterrhining the angular position of said filament when said lamp is mounted including a plurality of spaced openings in said flange, said flange being provided with cam edges having seating portions each of which has a predetermined angular relation to said filament.

THEODORE W. FRECH.

DISCLAIMER 2,033,699.-17wodore W. Fresh, Shaker Heights, Ohio. ELECTRIC PROJECTION LAMP. Patent dated March 10, 1936. Disclaimer filed April 10, 1939, by the assignee, GeneralElectric Company. P Hereby enters this disclaimer to claims 10, 11, 12, 13, and 14 of said Letters atent.

[Ofiicial Gazette May 2, 1.939.]

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