US2117135A - Illuminating device - Google Patents

Description

y 1938- E. s. BISSELL ILLUMINATING DEVICE Filed Dec. 8, 1934 EVERETT S. BISSELL.

ATTORNEY Patented May 10, 1938 ILLUMINATING- DEVICE Everett S. Bissell, Irondequoit, N. Y., assignor to Bausch & Lomb Optical Company, Rochester, N. Y., a corporation of New York Application December 8, 1934, Serial No. 756,674

Claims. (Cl. 240-1) The present invention relates to illuminating devices and more particularly to a unit for illuminating comparison optical instruments such as colorimeters, hemoglobinometers, comparison microscopes or the like.

One of the objects of the present invention is to provide a new and improved illuminating unit for comparison optical systems. Another object is to provide a lamp unit for projecting two separate and relatively variable beams of light. A further object is to provide a lamp for projecting two beams of light inwhich both beams may be simultaneously reduced. A further object is to provide a lamp having two angularly related plane reflecting surfaces and a single source of light movable with respect to said surfaces to regulate the relative amount of light reflected by each. These and other objects and advantages reside in certain novel features of construction, arrangement and combinations of parts as will hereinafter be more fully set forth and pointed out in the appended claims.

Referring to the drawing:

Fig. 1 is a perspective view of a lamp made in accordance with this invention.

Fig. 2 is a horizontal section of same.

Fig. 3 is a vertical section taken on line 3-3 of Fig. 1.

Fig. 4 is a detail view of the lamp mount.

A preferred embodiment of the invention is illustrated in the drawing wherein Ill indicates generally a housing having an upper portion II and a bottom l2 fastened to the upper portion by screws 13. The interior of the housing is made diffusely reflecting by coating it with a metallic paint such as aluminum paint. The top of the upperportion H has two openings l4 in which two plane glass windows l5 and I6 are held by two rings I1 and I8. symmetrically arranged with respect to the openings I4 is a third opening l9 and a bolt 20 is screwed into the portion ll adjacent the opening l9. A plate 2| has an extension 22 provided with a slot 23 for engaging the bolt 20. The plate 2| also has an opening 24 in which a ring 25 carrying a lamp socket 26 is held by a screw 21. A lamp 28 is fastened into the socket 2G.

Welded or otherwise suitably secured to the bottom plate I2 is a metallic plate 29 bent at 30 to form two plane angularly related surfaces 31 and 32. The plate 29 is symmetrically located beneath the windows l5 and I6 and each of. surfaces 3| and 32 is coated with a white reflective paint. As the opening I9 is larger than the base of the lamp 28, and the slot 23 is larger than the bolt 20, it is apparent that the lamp 28 can be freely moved within the housing In. As the lamp 28 is moved across the casing it is moved toward one reflective surface of the plate 29 and away from the other reflective surface and hence 5 the intensity of the beam reflected through one window is increased While the intensity of the beam through the other window is decreased.

Directly beneath the lamp 28, the bottom plate I2 is provided with a hole 33 in which a shaft 34 is rotatably mounted. A shutter 35 is fastened to the shaft 34 within the housing by means of a nut 36 and an operating handle 31 is fastened to the shaft 34 outside the housing by means of a nut 38. The shutter 35 is movable to a position between the lamp 28 and the reflective plate 29 and in the position reduces the total light passing through the windows 15 and I6 by approximately one half. By the use of this shutter, the light source 28 may be made sufficiently powerful to permit the use of the unit in a brightly lighted room and yet be dimmed to a suitable extent when the unit is to be used in a dark room. A ventilating opening 39 in the rear of the lamp house permits the escape of heated air.

With the present invention it is possible not only to equalize the two light beams, but it is also possible to compensate for slight differences in transmission between the two optical sytems of the colorimeter or other instrument used. Thus if one optical system has a lower transmission than the other due to dirt or some other cause, the beam entering that system can be made stronger until the two beams reaching the eye piece are equal in intensity.

While the two diffusely reflecting surfaces 3| and 32 are shown as angularly related at an obtuse angle, they may also be positioned at an acute angle to each other. That is, the plate 29 may be bent inwardly rather than outwardly and 40 still accomplish the same result. The two openings l4 may, of course, be replaced by a single opening extending across the top of the lamp house. Such a construction would be easier and cheaper to manufacture.

From the foregoing it is apparent that I am able to attain the objects of my invention and provide an illuminating lamp for projecting two separate and relatively variable beams of light. Various modifications can, of course, be made without departing from the spirit of my invention or the scope of the appended claims.

I claim:

1. An illuminating device comprising a housing having means permitting the passing of two spaced beams through one wall thereof, two fixed angularly related, diffusely reflecting members within said housing, one for each beam, a single light source movably mounted within said housing for regulating the .relative amounts of light reflected in each beam, means for clamping the light source in adjusted position and a shutter within said housing for controlling the amount of light reaching said reflecting members.

2. An illuminating device comprising a housing with a diflusely reflecting interior having two spaced openings in one wall, two plane, angularly related white reflecting members within said housing, one for each opening, a slotted plate outside of said housing, a bolt on said housing extending through said slot for clamping said plate in desired position, a source of light carried by said plate and extending into said housing through a third opening therein and a shutter movably mounted within said housing for movement to and from a position between said source and said members.

3. An illuminating device comprising a housing having means permitting the passage of two spaced beams through one wall thereof, two fixed, angularly related, diffusely reflecting members within said housing, one for each beam, a

single light source movably mounted within said housing for regulating the relative amounts of light reflected in each beam, and means for clamping the light source in adjusted position.

' 4. An illuminating device comprising a housing with a diffusely reflecting interior having two spaced openings in one wall, two plane, angularly related white reflecting members within said housing, one for each opening, a slotted plate outside of said housing, a bolt on said housing extending through said slot for clamping said plate in desired position, and a source of light carried by said plate and extending into said housing through a third opening therein.

5. An illuminating system for projecting two light beams of variable intensity comprising two plane reflectors positioned in inclined intersecting planes, a concentrating reflector facing said plane reflectors and fixedly positioned so that its optical axis substantially bisects the angle between said plane reflectors, a single source of light adjustably mounted between said concentrating reflector and said plane reflectors and means for moving said light source relative to said reflectors.

EVERE'I'I' S. BISSELL.

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