US2365864A - Means of illuminating telephone dials, etc. - Google Patents

Description

Dec. 26, 1944. H. E. CHAPMAN MEANS OF ILLUMINATING TELEPHONE DIALS, ETC

7 Filed March 25, 1942 C ATTORNEY 7 ,Patented 26 1944 Y UNITED MEANS OF ILLUMINATIN G TELEPHONE DIALS, ETC.

3 Claims.

This invention relates to illuminatingv telephone dials, radio dials, pressure indicators, speed indicators, or other types of indicating instruments,

-where illumination is not sufficient for proper visibility, by means of using a clear transparent plastic material or other characteristic material,

as a light transmitting medium without projecting undesirable light outside the instrument itself.

This lllumination is obtained by projecting light from a small electric lamp into the inner mass ofthe clear transparent plastic material, or other characteristic material, hereinafter referred to as plastic material, which is placed directly over the face of the instrument, or sub- .stituting the plastic material forthe engraved dial of the instrument and by means of having the engraving appearing on the plastic material.

This invention makes use of the fact that the plastic---material will in turn transmit the light throughout its entire mass, making the characters engraved on the face of the dial or instrumentclearly visible.

My invention will be more fully understood from thespeciflcation hereinafter followin by reference to the accompanying drawing in which:

Figure l is a plan view of a telephone dial to which my invention is applied; Fig. 2 is a transverse sectional view taken on line'2-2 of Fig. 3 and illustrating in plan the device of my invention applied to a telephone dial; Fig. 3 is a sectional' view taken through the device of my invention as applied to a telephone dial substantially on line 3-3 of'Fig. 1; Fig. 4 is a sectional view through the device of my invention showing the construction of the device for general application to dials for various instruments; and Fig. 5 is a theoretical diagram showing the system of light distribution provided by the device of my invention applied to dials of various arrangements.

In the drawing, reference character a represents a disc orring of plastic material, this ring of plastic material is the subject of this invention. Reference character 2 designates a thin film or layer of blue tinted plastic (with a small section'cut away in Fig. 5 to indicate its presence) glued, cemented or vulcanized on the entire surface of the face of the plastic ring i to further prohibit undesirable light outside the instrument and still permit the engraving on the dial to be clearly visible. Reference character 3 designates a circular opening to permit that part of a telephone dial which extends above the dial number plate to extend through the plastic material to allow it to fit evenly and flush with the dial plate. Reference character d indicates a smaller opening in the plastic. material l to permit a small electric lamp D to extend to or through the plastic material I The wall of this opening t is highly polished to permit all the light possible to be admitted to the inner mass of the plastic material l. Reference character t designates a small metallic or non-transparent plate to fit over opening t to prohibit direct light from the lamp being projected outside the instrument. Reference character i indicates two small pins permanently mounted on plate t to facilitate mountii'ig the plate upon the plastic material. These small pins are slotted on their outer end to provide a tension on the walls of holes 5, which are drilled in the plastic material 2! on either side of opening t to hold the plate t in place. The plate 6 is mounted in such manner to enable the lamps to be easily replaced. The walls of the circular opening 3 and the outside walls of plastic material 5! as indicated in Fig. 4, at reference character 8 are-treated to prohibit undesirable light from escaping from the plastic material at these points.

Fig. 4 is a cross sectional view of'Fig. 1 showing the light distribution device of my invention adapted for general application to dials of various descriptions. ihe device is toroidal in shape and will readily lit with one face thereof directly against the dial. The light reflective surfaces 8 are applied to the inner and outer peripheral edges of the device as heretofore explained and a light modifying film or layer 2 is provided over the opposite face of the device as heretofore ex-' plained.

Figs. 1, 2 and 3 illustrate the use of this invention in connection with a telephone dial, the letters in the illustration referring to various parts of the dial are used to clarify the illustration and are not a part of the invention, but the figures used to identify various parts of the illustration are a part of the invention.

Letter A, Fig. 3, designates the shellor case of a telephone dial, letter B designates the dial plate which carries the engraving identifying the steps of rotation of the finger wheel C, letter D designates a small electric lamp projecting through a hole cut in-the dial plate to coincide with the opening 4, Figs. 3, 4, 5, to act as an illuminating medium. Letter E designates the rotating shaft of the dial upon which the finger wheel C is mounted. In Fig. 2 the finger wheel is omitted to better show a faceview of this invention as used with a telephone dial.

In Fig. 3 the plastic material is identified by reference character I, the necessity of the opening identified as number 3 in Fig. 2 is clearly shown. Fig. 3 shows the lamp opening number 4 and the cover plate number 6 as being located under that portion of the finger wheel where no finger, hole punchings appear. The lamp D derives its operating current directly from the telephone line and becomes lighted as the telephone receiver is taken from the switchhook and remains lighted as long as the receiver is oil the switchhook.

What I claim and desire to secure by Letters Patent 01 the United States is as follows:

1. Means for illuminating a dial comprising a circular dial having an annular row of identifying characters carried thereon, a fiat ring of light distributing plastic material having a light transmitting face positioned adjacent the annular row of identifying characters on the dial, a light modifying film extending over the opposite face of said ring, light opaque means extending over the inner and outer edges of said ring, means extending through a portion of said ring for introducing light rays into the body of said plastic material, and a cover member engageable with a portion of said flat ring for obstructing direct emanation of light rays from said ring.

2. Means for illuminating a dial comprising a circular dial having an annular row of identifying characters carried thereon, a toroidal member of light distributing plastic material having a light transmitting face positioned adjacent the annular row of identifying characters on the dial. alight modifying coating on the opposite face of said member, light reflecting means covering the inner and outer peripheries of said member, a light source extending through a portion of said member for illuminating the interior of said member by disseminating light rays through said member by reflection from said light reflecting means, and a cover for housing said light source removably engaging a portion of said toroidal member.

3. Means for illuminating a dial comprising a circular dial having an annular row of identifying characters carried thereon, a toroidal member of light distributing plastic material having a light transmitting face positioned adjacent the annular row of identifying characters on the dial, a light modifying coating on the opposite face of said member, light reflecting means covering the inner and outer peripheries of said member, a light source extending through a portion of said member for illuminating the interior of said member by disseminating light rays through said member by reflection from said light reflecting means, and a disc-like light opaque device removably engageable with a portion of said toroidal member for confining the light rays from said light source to the body structure of said toroidal member.

HARRY EDWIN CHAPMAN.

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