US2190875A - Miniature bulb and socket construction - Google Patents

Description

Feb. 20, 1940. M. KLEIN El AL MINIATURE BULB AND SOCKET CONSTRUCTION Filed Nov. 29, 1938 Patented Feb. 20, 1940 2,190,875

UNITED STATES PATENT OFFICE MINIATURE BULB AND SOCKET CONSTRUCTION Maximilian Klein, Sellersville, and William E. Pfefier, South Perkasie, Pa., assignors to United States Gauge Company, Sellersville, Pa a corporation of Pennsylvania Application November 29, 1938, Serial No. 243,048

' 6 Claims. (Cl. 176-32) The present invention relates to a novel elecview through a bulb socket made in accordance tric lamp and socket structure especially dewith the present invention and illustrating the signed for the illumination of instriunents, such novel bulb in operative relation thereto. as gauges of all kinds. electrical indicating in- Figure 2 is an enlarged transverse sectional struments, clocks or the like. More particularly, view of the novel bulb assembly of the present 5 the present invention relates to a novel miniainvention illustrating the manner of insulating ture lamp and socket structure adapted for use the contact elements from each other and of in the illumination of dial and pointer instrusecuring the glass bulb assembly in place. ments, which permits ready application of the Figure 3 is a view of the bulb of Figure 2.

l0 lamp to the socket with the lamp bulb extending as seen from the front of the bulb. away from the part that is gripped by the fingers Figure 4 is a view of the bulb of Figure 2 as in inserting the lamp in the instrument. seen from the rear of the bulb.

Electrical bulbs for indicating instruments are Figure 5 is a view similar to Figure 2 illusextremely small, having an overall length of trating a modified form of bulb'assembly. approximately one-half an inch and a diameter With continued reference to the drawing 15 of approximately one-eighth of an inch. As wherein like reference numerals are used to ina result of the small size of these bulbs, diflidicate the same parts throughout the several culty has been experienced in assembling the figures, numeral ill indicates generally a lamp glass bulb with its extremely fine filaments in made in accordance with the present invention, the bulb base. v and numeral ll indicates generally the novel 20 It is a primary object of the present invention socket of the present invention. to provide a simple base structure that will Lamp it! comprises a glass bulb l2 having the enable ready assembly and connection of the usual filament l3 therein and protruding filaglass bulb and filament to the base. ment connections l4 and I5 extending from the A further important object of the present inrear of the glass bulb. Glass bulb i2 is pref- 25 vention resides in the provision of an electric erably manufactured in accordance with well lamp or base assembly having one contact in known practices and is associated with the novel the form of a sleeve at the front end of the bulb base assembly l6 of the present invenassembly, and the other contact likewise of tion in the following manner:

go sleeve-like form but disposed at the rear end Base assembly l6 comprises a metal sleeve ll of the assembly, so as to provide the peripheral having an annular flange l8 at one end theremargin of the base. of. Sleeve l'l comprises one contact element for A further object of the present invention rebulb i0 and is connected to filament lead i i sides in th provision of an electrical lamp base by a suitable soldering operation at is.

made up of three relatively simple sleeve-like ele- After sleeve I1 is connected to filament lead 35 ments designed to be held in assembled relation 14, insulating sleeve 2i is telescoped thereon with each other and with a suitable cement until the shoulder i8 abuts against the end 22 serving to encase the bulb at one end and thus of sleeve 2|.

provide the lamp base. The assembled glass bulb i2, sleeve. H and Still another object of the present invention sleeve 2| is then provided with a further sleeve 40 resides in the provision of a novel combination 23 having an annular flange 24 at one end thereof holding cap and lamp designed to permit of. Sleeve 23 is also provided with a shoulder easy replacement of the lamp in the cap. 24a designed to abut end 25 of sleeve 2|. A

A further object of the present invention resplit ring 24b is loosely disposed on the portion 5 sides in the novel association of a socket, proof sleeve 23 between flange and shoulder 24a.

vided by a bore in the casing of an indicating Ring 24b in its expanded position extends be or light instrument, and a miniature lamp and yond the periphery of sleeve 2| and flange 24 lamp holder permitting illumination of the infor a purpose to be presently pointed out. Sleeve strument interior upon assembly of the lamp and 23 with ring 24b in place is forced into the holder in said bore. opposite end of sleeve 2| until shoulder 24a 50 Further objects of the invention will appear abuts end25 of sleeve 2i. Filament lead i5 is from the following description when read in then soldered to sleeve 23 at 28. Bulb assembly conjunction with the appended claims and at- III is then filled with a suitable cement 21 by tached drawing wherein: pouring the cement in its plastic condition into Figure 1 is an enlarged transverse sectional the open rear end of bulb assembly [0. Cement 55 ring 5| fits' recess 33 snugly so as to be retained by 21 completely fillsthe space between glass bulb |2 andsleeves l1, 2| and 23 so as to firmly connect these elements together.

From the above description it will be clear that.

bulb I0 is made of relatively few and simple parts, and that, due to the fact that the various parts are readily accessible during the assembly operation, very little difilculty' is experienced in making the soldered connections I9 and 26, and in assembling the glass bulb |2 with its base I6.

While bulb 0 may be used in any suitable socket structure, the socket structure U of the present invention is at present preferred. Socket II is specifically described and claimed in applicants' co-pending application Serial No. 243,047, filed on even date herewith and entitled Miniature bulb and socket construction. Socket comprises a body portion 3| of insulating material having a bore 32 therein. Body portion 3| may be formed as an integral part of the casing of an indicating instrument, which is to be illuminated by the lamp of the present invention. The upper end of bore 32 is preferably recessed, as at 33 to provide an annular shoulder 34. At suitable points in the interior of body 3| the walls of bore 32 are provided with longitudinally extending grooves 35 and 35. Grooves 35 and 36 receive electrical conductors 31 and 38 which are connected in any suitable manner to a source of electrical energy.

Conductor 31 preferably constitutes the live conductor and is provided with an annular contact portion 39 having a centrally disposed opening 4| therein. Inorder to properly position contact 39 in bore 32, conductor 31 is secured to an insulating sleeve 42 as by means of suitable arms 43 carried by the conductor which pass through suitable apertures 44 in the wall of sleeve 42. Arms 43 are bent over so as to clamp portion 45 of sleeve 42 at 46. Sleeve 42 with conductor 31 secured thereto is then inserted into bore 32, preferably from the lower end, and forced upwardly through bore 32 until contact 39 is at the proper level. While a frictional fit between sleeve 42 and bore 32 is usually sumcient to retain the sleeve in proper position, suitable cement may beused.

Conductor 33 in groove 36 extends beyond the shoulder 34 and is then bent over to provide a portion 48 in engagement with shoulder 34 and a portion 49 in engagement with the wall ofrecess 33 of bore 32. A metal ring 5| having internal threads 52 therein 'is positioned'in recess 33 and clamps portions 48 and 49 ofconduit 38 in place.

Metal ring 5| may be associated with body 3| in any suitable manner. Preferably, however, the

friction.v The body 3| is made of insulating material such as Bakelite", it is to be understood that ring 5| may be cemented to said body if desired.

Ring 5| in the illustrated embodiment is adapted to receive an externally threaded lamp-receiving metal cap 53 having an internal bore 54 therein. Bore 54 receives base I6 of lamp l0. As base I5 is inserted into bore 54, ring 24b is contracted and, due to its tendency to expand frictionally, secures lamp ID in cap 53 so as to permit handling of the assembly as a unit. In its final position in cap 53 lamp l0 engages the tapered walls 55 of cap 53 along the corners of contact 24. Engagement of walls 54 and contact 24 insures an adequate electrical contact between the cap and the lamp. Cap 53 completes the return circuit from filament l3, contact 24 to metal ring 5|, and conduit 38. When the cap 53 is firmly screwed in the ring 5|, the flange l3 of contact sleeve |'I bears against contact ring 39, current flowing to the filament from conductor 31, through ring 39, sleeve to the filament l3. It will be understood that a suitable opening is provided in the wall of the socket so that the rays of light emanat- I ing from the lamp may pass in the direction needed to properly illuminate the dial and/or pointer of the instrument, all as more completely described in the application of Maximilian Klein and William E. Pfeffer, entitled Illuminating indicating'instruments, filed on even date herewith.

While the socket ll of the present invention has been described as being formed from a body 3| of insulating material, it will be appreciated that body 3| may be formed of metal by use of a suitable insulated conduit .31. If such a structure is resorted to, ring 5| and conduit 38 may be omitted and the cap 53 may be screwed directly sembly substantially like that shown in Figures 1 to 4. This form of the invention differs from that previously described in that sleeve 23 is omitted and a second sleeve I1 is substituted therefor. In all other respects, this form of the invention is like that previously described. As a consequence, the same reference numerals have been employed and a detailed description is believed to be unnecessary.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodimentsare therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being-indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A lamp, comprising a closed bulb having a filament therein, and a base consisting of two conductor sleeves disposed in spaced relation endwise of said bulb, said sleeves being of equal diameter, an insulating sleeve electrically separating said conductor sleeves and forming with said conductor sleeves a base having smooth external surconductor sleeves.

terial cooperatingwith said sleeves to-complete said base, said conductor sleeves and said insulating sleeve being formed to provide said base with a smooth and uninterrupted external surface.

4. An electric lamp having a base including two identical axially separated contacts each of which is in the form of a sleeve having one end terminating in an external annular flange, and an insulating sleeve separating said contacts, said base being adapted for assembly with a standard bulb structure by telescoping either end of said sleeve over the predetermined end of said bulb structure.

5. An electric lamp, comprising a bulb having a filament therein and a base consisting of two conductor sleeves disposed in spaced relation endwise of said bulb, an insulating sleeve electrically separating said conductor sleeves, said conductor sleeves and insulating sleeve together forming a smooth external annular wall, a split snap ring interposed between a portion of one of said conductor sleeves and said insulating sleeve, connections between said filament and said conductor sleeves, and cementitious material in certain of said sleeves providing a closure completely housing one end of said bulb.

6. A lamp and cap assembly, consisting in a cap having a smooth cylindrical bore for the removable reception of the base of said lamp, a normally expanded snap ring mounted in the external wall 01 said base for frictionally engaging the wall of said bore to removably secure the lamp in said cap, a threaded connection on said cap for connection to a socket and a portion on said cap providing a finger grip to permit the cap with the bulb therein to be threaded into said socket;

MAXIMILIAN KLEIN. WILLIAM E. PFEFFER.

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