US1273994A - Lamp. - Google Patents

Description

w.I. BGH/IN.

LAMP.

APPLICATION FILED 0cT.5,I9I1.

1 ,273,994. Patented July 30, 1918.

`of Fig. 1.

WILLIAM J. ROHAN, 0F ST. PAUL, MINNESOTA.

. LAMP.

Specification of Letters Patent.

Application Bled October 5, 1917.A lSerial No. 184,985;

To all whom Ait may concern.'

Be it known that I, WILLIAM J. BOHAN, a citizen of the United States, and resident of St. Paul, county of" Ramsey, and State of Minnesota, have invented certain new and useful Improvements in Lamps, of whichv the following is a specification, and which are illustrated in the accompanying drawings, forminga part thereof. l

The invent-ion relates to lamps in which the illuminating agent is `an incandescent bulb, or equivalent device, and in'which the bulb is located within a projecting reflector.

The object of the invention is to provide improved means for focusing the bulb with reference to the reflector; and .it consists in a structure such as is hereinafter described and as illustrated in the' accompanying drawings, in which- Figure 1 is a longitudinal section through the lamp; and 1 Fig. 2 is a sectional view on the line 2-2 The lamp comprises a casing or shell 10, here shown as bowl shaped and having a hollow stem 11 which is externally threaded.

- ranged and equally s The lamp may be supported by any suitable means, such as a bracket-arm '12. secured to the shell. A projecting reflector 13 is housed within the shell, and is apertured at its inner end, as shown at 14, to accommodate the base 15 of an incandescent bulb 16. 'lo the base 15 is suitably attached a cap 17 fitting over the stem 11, this attachment being preferably by means of threaded engagement with a tubular stem 18- rojecting inwardly from the cap 17 and) through which theleading-in wires 19 may be conveniently entered. `7 The annular flange 20 of the cap 17 issecured to a collar 21 in threaded engagement with the stem 11 by mea-ns of annularly- arcedadjusting screws 22, 23, 24 and 25. e diameter of the annular flange 20 is vsufficiently greater than that ofthe collar 21 to permit lateral adjustment of tl e cap through the agency of the adjusting screws lrews have their inner ends rounded, asy in cated at 26, to engage an annular groove 27 in the periphery of the collar 21. Jam nuts, as 28. may bc mounted upon tbeadjusting screws toengage the outer face of the flange 20.

The described construction provides for the universal adjustment of the bulb 16 with reference to the reflector 13. By turning up ,Patented July 30,1918.:

one of a pair ofidiametrically disposed `ad- Justing screws and turning back the other screw of the same pair, the cap 17, and with it the bulb 16, may bemoved laterally. The members of the other pair of screws will, of course, be setl up tightly against the collar after such adjustment, in order to securely bindithe parts together. By shifting the collar 2:1 upon the stem 11, the capand bulb may be axially adjusted. The two adjustments, therefore, permit the locating of the bulb at any point within the chamber of the reflector, thereby Securing an accurate focus of the lamp.

Incandescent bulbs lack uniformity of construction, the filament of whatever formed, being differently positioned in many instances. Adjustment4 becomes necessary where, as in locomotive headlights, high efficiency is required. -Readjustment is frequently necessary owing to a tendency of the filament to sag when heated, as indicated by dotted lines in Fig. 1. v

While a preferred embodiment of the invention is illustrated, various. structural changes may be made withgut departing from its scope.

I cla-im as'my invention- .1. In a projecting lam in combination, a shell having an externally threaded tubular stem, a reflector housed within the shell and having an aperture in its inner end, an incandescent bulb located within the reflector, the lbase of the bulb extending through the aperture thereof, a collar in threaded engagement with the stem of the shell, a cap attached to the base of the b ulb and having a, flange surrounding the collar and spaced apart therefrom, and adjusting screws in threaded engagement'with thel flange and bearing upon the collar.

2..In a projecting lamp, in combination, i

a shell having an externally threaded tubular stem, a reflector housed within the shell and having an aperture at its inner end, a cap overlapp'ingrthe stem of the shell and having an axially tubular Astem entering and of less dia-meter'than' the stem of the shell, -an incandescent bulb located within the reflector and having its'base attached to the tubular stem of the cap, avcollar in threadedv engagement with the stem of the shell, and

adjusting screws"connecting the cap with-the no lar stem, a reilector housed Within the shell and having, an aperture at its inner end, an incandescent bulb located WithinA the reector, the base of the bulb extending through the aperture thereof, a. collar in threaded engagement with the stem of the shell, and a bulb carrier secured to the collar and being lateral-ly adjustable with reference thereto.

4. In a projecting lamp, in combination, a shell having a tubular stein, a reilector housed Within the shell and having an aperture at its inner end, an incandescent bulb located within the reflector, the base of the bulb extending` through the aperture thereof, a collar mounted and axially adjustable on the stem of the shell, and a bulb carrier secured to the collar and laterally adjustable with reference thereto.

5. In a lamp support, in combination, a tubular stern, a collar threaded upon the stem, and a c ap having a socket for receiving a lamp base and being secured to the collar and laterally adjustable with reference thereto.

WILLIAM J. BOHAN.

Copie: ot this patent my be obtained for ve cents each, by addressing the Commissioner of latents,

' Washington, D. C.

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