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Publication numberUS2275621 A
Publication typeGrant
Publication dateMar 10, 1942
Filing dateSep 10, 1940
Priority dateSep 10, 1940
Publication numberUS 2275621 A, US 2275621A, US-A-2275621, US2275621 A, US2275621A
InventorsGardinor Elliott W
Original AssigneeIbm
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Illuminated dial
US 2275621 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

March 10, 1942. w GARDINQR 2,275,621

ILLUMINATED DIAL Filed Sept. 10, 1940 NTOR ATTORN EY Patented Mar. 10,

to International Business Machines Corporation, New York, N. Y., a corporation of New York Application September 10, 1940, Serial No. 356,148 3 Claims. (01. 240-4.!) This invention relates to a clock dial structure and means for illuminating the same. I

The general objectof the instant invention is to provide improved illumination for a clock dial by special arrangem nt of a light-source and light directing surfaces to effect a substantially even distribution of light over the dial.

More specifically, an object of the invention resides in the provision of illuminated gas-filled tubing located between the dial and the hands of the clock to prevent the clock hands from casting shadows on the surface of the dial.

Another object is to provide a clock dial having a special curvature to aid in reflecting the light from a source mounted behind the clock hands and adjacent the central portion of the dial.

It is also an object to provide an opal glass disk novelly mounted between the light source and the, clock hands for diffusing the light passing therethrough so as to lend a more pleasing ap-. pearance to the illuminated clock dial.

The invention contemplates employing a dish shaped dial for aiding in directing the light more eifectively from a circular tube filled with a suitable gas, such as neon, and mounted directly in front of the central portion of the dial. An opal glass disk is placed in front of the tube and the clock hands are located in front of the disk. With'this arrangement, part of the light dlifuses through the disk and part of the light strikes the curved surface of the dial and is reflected outwardly. In'view of the fact that the clock hands are mounted in front of the light source and the disk, there can be no shadows .cast by these hands in. the direction of the dial. The rear lighting of the clock hands makes their position and identification more readily determinable at a glance.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawing, which discloses, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle. In the drawing:

Fig. 1 is a face view of the clock.

Fig. 2 is a section taken on line 2-2 of Fig. 1.

Fig. 3 is a sectional detail view showing the connection between the dial and a rim which also holds the customary glass cover protecting the clock face.-

Referring now to the drawing, It represents a drum containing the necessary clock mechanism for driving stub shafts II and I2 to which are the center of the dial. In

attached an hour hand ll and a minute hand I4,

, ture.

respectively. The clock mechanism in itsel forms no part of the present invention.

v A plate i5, integral. with the right end of the drum as viewed in Fig. 2, is provided with mountlng brackets i5 bolted to the plate at spaced intervals around its periphery. Bolts H, which are employed to connect the brackets with the plate, also serve to fasten an opal glass disk IE to the supporting plate IS with the cooperation of nuts l9 and 20. Disk is is formed with a central hole to provide clearance for shafts ii and ii. The thicknesses of brackets 16 and of the nuts 20 cause a space to be left between the disk [8 and the supporting plate i5 which helps provide clearance for a circular glass tube 2| placed immediately behind the disk l8 and directly in front of a clock dial 22.. The tube 2| is filled with gas, such as neon, and is illuminated in a well known manner'by application of a suitable difference of potential to terminal members 2m and 2lb which pass through holes in the dial 22 and help support the tube in the position shown in the drawing. The clock dial itself is secured to the brackets i 6 by bolts cooperating with nuts 24. A circular ring 25 serves as a backing for the dial to strengthen the bolted connections with the brackets.

The clock dial 22 is made concave, resembling in shape anordinary dish. The reason for pro viding such a curvature to the dial is'to improve the reflection of light rays from illuminated tube 2| which impinge on the surface of the dial. A considerably larger portion of the light from the tube reachesdial 22 directly by virtue of its curvature than would fall on a flat dial mounted at the same place.

A suitable rim 25 is provided to cover the outer edges of the dial and of a protective glass 28. The glass and the dial areclamped together at the edges by the cooperation between the front of the rim 25 and springclip 21 carried by the run. A substantially even distribution of light on the dial is-obtained by the above described struc- The light which tends to come directly out to the front from tube 2| is difl'used by the opal disk I 8. The light which tends to directly seek out the rim 25 is intercepted by the curved surface of the dial 22. By locating the light source in the manner shown, rather than in the rim as is customarily done with a tubular light source, lsto greatly reduce the shaded portion around I the arrangement presentedherein, the light source is considerably closer to the center of the dial and the light is on the clock dial.

softened by diffusion. As the clock hands it and il rotate in front of the light source and the diffusing disk, they cannot cause shadows to fall While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutions and changes in the form and deillustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. A clock case construction comprising, in combination, a supporting plate at the rear of said case, a concave dial secured to said plate, a luminous gas tube positioned about the center of the dial and intermediate the center of the dial and its edges, an opalescent element carried by the supporting plate and spaced therefrom so as to be located immediately in front of the tube, and clock hands supported in front of the element for cooperation with the dial.

screen 2. A clock case construction comprising. in combination, a supporting plate at the rear of said case. a concave dial secured to said plate, a circular tube containing luminous gas positioned about the center of the dial, the diameter of the dial being substantially greater than the diameter of the circle formed by the tube, an opalescent material carried bythe supporting plate and spaced outwardly therefrom so as to be located in front of the luminous gas tube, and clock hands supported in front of the material for cooperation with the dial.

3. In combination, a supporting plate, a concave clock dial fastened to said plate, a luminous gas tube located in front of the dial and adjacent the central portion of said dial, an opalescent material carried by the supporting plate spaced therefrom a distance suiilcient to locate the material in front of the tube, clock hands supported in front of said material and cooperating with the dial, a glass panel in front of the hands for covering the dial, and a rim around the edge of the dial for holding the outer edges of the materlal against said dial.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2812421 *May 10, 1954Nov 5, 1957Archer John LIlluminated electric clock
US2868959 *Jun 29, 1955Jan 13, 1959Alfred M MayoMoisture-proof illuminated instrument
US4916580 *Sep 22, 1988Apr 10, 1990Hitachi, Ltd.Back-light device
US5669692 *Nov 17, 1995Sep 23, 1997Timex CorporationFiber optic lighting system
US5964514 *Sep 24, 1997Oct 12, 1999Chrysler CorporationIlluminating instrument panel gauge with indicator and graphics
US8052309 *May 31, 2007Nov 8, 2011Jacob DysonLighting system with reflector that moves in a periodic manner
U.S. Classification362/23.18, 968/213, 368/227, 362/23.1
International ClassificationG04B19/30
Cooperative ClassificationG04B19/30
European ClassificationG04B19/30