US 3859782 A
A clock having a case within which is mounted a dial with time indicia on the face thereof. The face of the dial is illuminated by a light source disposed on a backside of the dial. A light-transmitting tube is disposed concentric with the dial and extends axially therethrough. Light from the light source is transmitted through the tube to an illumination device adjacent the frontside or face of the dial. The illumination device may be a reflector made integral with the clock "glass" or a separate edge-lighting disc. A condensing lens may be placed on the tube to improve light transmission to the illumination device. The reflector can have inclined surfaces for transmitting shafts of light to corresponding time indicia.
Description (OCR text may contain errors)
States atent 1191 Kitai Jan. 14, 1975 CLOCK WITH ILLUMINATION DEVICE Primary ExaminerGeorge H. Miller Jr. 1 K t T k  mentor lyoshl Kl 0 yo Japan Attorney, Agent, or Firm-Robert E. Burns;  Assignee: Seiko Koki Kabushiki Kaisha E manuel J, Lob m; Bruce L, Adams  Filed: May 7, 1974 21 Appl. 190.; 467,749  ABSTRACT A clock having a case within which is mounted a dial with time-indicia on the face thereof. The face of the  Forelgn Apphcatmn Pnomy Data dial is illuminated by a light source disposed on a May 9, 1973 Japan backside of the A lighbtransmitting tube is disposed concentric with the dial and extends axially U-S. R the ethr ugh from the ource is transmit- Cl. n ted through the tube to an illumination device adja Flew of Search 53/50 50 A cent the frontside or face of the dial. The illumination device may be a reflector made integral with the clock References Clted glass or a separate edge-lighting disc. A condensing UNITED STATES PATENTS lens may be placed on the tube to improve light trans- 666,381 1/1901 Gareau 58/50 R mission to the illumination device The reflector can 2,212,359 8/1940 Wil x 533/50 R have inclined surfaces for transmitting shafts of light 3,430,433 3/1969 Sandor 58/50 R to corresponding time indicia. 3,490,226 1/1970 Anderson et al 58/50 R 3,590,233 6/1971 Protzmann et al 553/50 R x 6 Claims, 2 Drawmg Flgures I a a L k iaa CLOCK WITH ILLUMINATION DEVICE BACKGROUND OF THE INVENTION This invention relates generally to clocks and more particularly to clock illumination devices.
Different illumination device constructions for illuminating clock dials are known. Some of the devices have an electric bulb mounted in the center of the dial. These devices generally do not illuminate the entire face of the dial uniformly and the leads to the electric bulb generally are obstructed by the watch movement or interfere therewith so that the construction thereof is relatively complex. Other illumination techniques are known such as mounting a plurality of light bulbs spaced around or about the dial face. This does not provide for uniform illumination. In order to provide for uniform illumination over the dial face the use of a circular florescent lamp has been employed. However this requires that the clock be made quite large and the appearance of the face of the clock is not pleasant.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a compact clock instruction with a new and improved illumination device.
According to the invention a clock is provided with a case internally of which is disposed a dial provided coaxially therewith with a central tubular element through which light is conducted from a source of light behind the dial. The light is transmitted to an illumination device, which may be a reflector, disposed spaced relatively to the face of the dial and made integral with the clock glass or crystal or independent thereof. The illumination device is constructed to reflect or apply the light on the dial face in rays of light in registry with the time indicia on the face of the dial. In order to improve the transmission of light through the tubular element, to the illumination device, a condenser lens may be provided.
Another feature of the invention is the provision of parts of a watch movement coaxial with the tubular light-transmitting tube and rotatably mounted thereon in order to make the clock compact.
BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of a clock according to the invention will appear from the following description of an example of the invention, and the novel features will be particularly pointed out in the appended claims.
FIG. 1 is a side elevation view of a clock according to the invention;
FIG. 2 is a fragmentary sectional view of details of a second embodiment of a clock according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS A clock according to the invention is illustrated in FIG. 1. The clock comprises a case 1 internally of which is mounted a dial 2 with time indicia on the face thereof. The face of the dial is viewed through a transparent front face plate 3 made of glass or acryl resin or some similar substance. The backside of the dial is provided with a plurality of internally threaded tubular elements 4 disposed circumferentially relative to each other. A base plate or backplate 5 is mounted on these elements with screws 6.
An open ended, light-transmitting tube 7 is disposed coaxially with the dial and back plate and secured to the latter and extends axially forwardly of the face of the dial 2. A reflector 8 made integral with the transparent front plate or glass is disposed spaced from the light-transmitting tube and coaxial therewith. It receives light from a light bulb 9 which transmits its light through the tube 7 onto the reflector 8. The reflector reflects the light back on the dial face.
The reflector 8 can produce an aesthetic effect by being designed in various forms, for example if it is made in dodecagonal conical form as shown in the drawing. At the same time the inclined surfaces thereof can be made to direct light rays or shafts of light to the time indicia on the dial face. Light will be reflected radially from the reflector surfaces and impinged directly on the same time indicia as well as beautifully illuminating the face of the dial. A condensing lens 10 is mounted on the after end of the tube 7 and improves the transmission of the light through the tube 7. It is, however, not necessary to the invention.
The electric light bulb 9 is mounted in a socket 11 fixed on the backside of the base plate 5. Electrical connections or leads 12 are connected to the socket for connection to an external power source or an internal battery, not shown, as the case may be.
The clock is provided with a watch movement which has parts disposed coaxially with the light-transmitting tube 7. Thus a minute-hand tubular shaft 13 is rotatably mounted on the tubular element on shaft 7 and coaxially therewith is mounted an hour-hand tubular shaft 14. The hour-hand tubular shaft is rotatably mounted on the minute-hand shaft 13. A minute-hand 15 is mounted on the forward end of the minute-hand shaft 13. An hour hand 16 is mounted at the forward end of the hour-hand shaft.
The motive power of the clock mechanism or movement, not shown, comprises an electric motor, for example a synchronous motor, coupled to the minutehand shaft 13 through a gear 17 thereby the minutehand is rotated at a definite speed. The minute-hand shaft 13 rotation is transferred to the hour-hand shaft 14 through a small gear 18, a large gear 20 meshing with a small gear 18 and supported by a shaft 19, another small gear wheel 21 fixed to the large gear wheel 20 and another large gear 22 meshing with the small gear 21 and fixed to the hour-handshaft 14. The hour hand is thereby rotated at a definite speed which lower than the speed of rotation of the minute-hand.
It is possible to make the reflector in various configurations such as conical or star-shaped. It is likewise possible to eliminate the reflector by using the flat surface of the transparent front plate 3 as a reflector. If made conical the apex of the cone is closer to the dial face than the base thereof.
A second embodiment of a clock according to the invention is illustrated in FIG. 2. The fragmentary illustration shows a dial 2' and a clock plate or glass 3. A light-transmitting open ended tube 7 is disposed with a minute-hand tubular shaft 13 and an hour-hand shaft 14' rotatably mounted thereon as before described. A minute-hand l5 and the hour-hand 16' are likewise illustrated.
In this embodiment a reflector 8' made of acrylic resin, glass or some other reflective material is installed in the forward end of the light-transmitting shaft 7 The reflector 8' has a circular edge-lighting portion 23 having a light-receiving axial projection 24 which is inserted and held in the light-transmitting tube 7 The circular edge-light portion or disc 23 of the reflector transmits light radially outwardly through its peripheral surface 25 thereof and transmits this light to the face of the dial 2.
The circular edge-light portion 23 may be constructed with a proper number of rod like bodies, not shown, extending radially therefrom in aligment with the time indicia on the face of the dial 2 for transmitting rays of light directly to the light indicia. Moreover the peripheral surface edge 25 may be made as a rough surface to carry out edge-light effects efficiently.
What I claim and desired to secure by Letters Patent l. A clock comprising, a case, a dial mounted internally of said case and having time indicia on a face thereof, a light-transmitting open ended tube coaxial with said dial and extending therethrough, a light source disposed spaced from a backside of said dial transmitting light through said tube and forwardly of said dial, illumination means disposed spaced from the 4 t face of the dial, receiving the light transmitted through said tube and transmitting it on to the face of the dial.
2. A clock according to claim 1, including a condensing lens receiving light from said light source and transmitting it through said tube to said reflector.
3. A clock according to claim 1, in which said illumination means comprises an edge-light transmitting disc having an axial light-transmitting extension received in an end of said light-transmitting tube, said disc transmitting light along a peripheral surface thereof on to the face of the dial.
4. A clock according to claim 1, in which said illumination means comprises reflector means comprising a plate at least semitransparent, closing the case and through which said dial is viewable.
5. A clock according to claim 4, in which said reflector means comprises a plate having some transparency for viewing said dial therethrough, and having a central region conical in configuration and having an apex nearer the dial than a base of said configuration.
6. A clock according to claim 5, in which said reflector means comprises surfaces for reflecting individual shafts of light on to corresponding time indicia.
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