US2561672A - Dial plate - Google Patents

Description

July 24, 1951 N. PRmmN 2,561,672

DIAL PLATE Filed June 14, 1947 ff 1f WAVE |||| |||v| ||||||u| hmm/ LZ? f l1: up." luulnnnln, mlm

Patented '.Iuly 24, "1'951 :y

UNITED STATES PATENT OFFICE I `lnrAL PLATE, Nathanrritikin,"ohicagt, nl. Y Application nine. 14, 194.7,.seria1N. 754,730

4 canali. (ci. i1-.22)`

The invention relates to dials or signs and particularly to those adopted for edge lighting.

In standard `practiceidials,"as for' instance used for radios, are made of a glass plate .on which the calibrations are indicated anda sheet.` metal penetrates, the metal backer must have like portion cut out in registry with the'unpainted portions so that edge lighting may be used. I

The provision of a metaltbacker and the form- `ing of the cut out portions isquite expensive.

Attempts fhave been made `to eliminate the backer and to merely apply an opaque color to the rear side of the dial plate. However, in such cases the dial plate does not lend itself to edge lighting.

It is, therefore, an object of the invention to provide a backer of transparent material and paint the hacker with an opaque color, except the portions which coincide with the unpainted portions of the dial plate.

It is a further object to provide a transparent backer which is secured to the dial plate to obviate interference with the edge lighting.

With these and other objects in View which will become apparent from the disclosure of the invention, the latter comprises the means described in the following speciiication, particularly pointed out in the claims forming a part thereof, and

illustrated in the accompanying drawing in which:

Fig. 1 is a front view of a known radio dial plate.

Fig. 2 is a section on the line 2 2 of Fig. 1.

Fig. 3 is a front view of the improved dial plate.

Fig. 4 is a section on the line 4 4 of Fig. 3, and

Fig. 5 is a fragmental longitudinal section somewhat enlarged of a modiiication.

In standard practice dial plates made out of glass are provided with a metal backing. As shown in Fig. 1, III designates a dial provided with calibrations II and numbers I2 denoting frequencies. The dial Ill is provided with transparent portions I3 and I4 in the form of slots through which the index hands are visible. A metal backing plate I5 co-extensive with the dial plate is provided with slots I5 which respectively coincide with the dial portions I3 and I 4. The backing plate I5 is formed with lugs II and I8 which are bent over the dial plate to secure the backing plate thereto.

The dial plate and the backing are separated by a very narrow air space so as to render the `edge lighting effective.

whichdoes not employ a metal backing butin lieu thereof employs a transparent material as a backer.

` '.The dial plate 2U is similar to the dial plate Ill and has also the calibrations 2l and frequency .numbers 22 and unpainted portions 23 and. in

the form of slots.

A backing plate 25 of transparent material such as glass and .co-extensive with the dial plate` 20 ,is painted withan opaque .color 26`but left unpainted to .provideslot like transparent portions 2'! co-extensive and in registry withltheportions 23and 24of.the dial plate `2li. 1`

The backing plate '25 is secured to the `dial plate 213 by an appropriate cement 28 applied at the edges. When the plates 20 and 25 are thus secured together there still remain an air space 29 therebetween so that edge lighting may be eiectively applied. I

In Fig. 5 a modification is shown wherein the dial plate 30 and the backing plate 3| are made of a transparent plastic material and secured together by a cement 32 leaving a slight air space 33. The modification in all other respects is the same as the embodiment shown in Fig. 3.

While the drawing illustrates the invention in connection with a dial, it is understood that it may be applied whereby legends on a plate are to be illuminated by edge lighting.

Changes and modifications within the spirit and scope of the invention are included as defined in the appended claims.

I claim:

1. In an indicia plate structure of the known type having indicia markings situated in transparent areas bordered by relatively opaque areas and adapted to be illuminated by edgeglow light transmitted interiorly of the plate from an edge region thereof, improvements including the following, to wit: backing means for said rst-mentioned indicia plate and comprising a second plate member mounted in closely confronting parallelism with said rst plate, said second plate having transparent areas registered with the said 3v pable of transmitting light internally by edgewise illumination, said pl-ate having indicia characters thereon and scalar markings situated in transparent frame areas on said plate, said characters 4and markings being adapted to be illuminated by edgeglow transmission internally of said plate; and a plate-backing structure consisting of a thin plastic sheet of the same size as nation of said characters and markings.

3. For use with a transparent dial plate hav- 4ing indicia characters thereon which are adapted to be illuminated by light transmitted internally of the plate from the edge regions thereof, said indicia characters including a plurality of scalar calibrations contained Within a frame .area surrounding the same, improvements comprising, to

wit: a backing member for said plate and consisting of a sheet of thin transparent material having an opaque substance thereover except in frame areas identically registering with the frame areas on the plate, said backing sheet being secured to the dial plate in closely but finitely spaced relation thereto to afford an -air space therebetween. y

4. A dial plate structure for edgeglow illumination by transmission of light into an internally light-conductive plate from edge regions thereof, said structure comprising, to wit: the combination with a transparent dial plate having indicia thereon including at least a series of scalar calibration marks thereon, and a transparent framearea surrounding said marks, said calibration marks being delineated by a material adapted to become luminously legible by light transmitted interiorly of the plate, as aforesaid; together with a backing. member consisting of a thin body of transparent material mounted against the back of said dial plate and having an opaque substance applied thereto throughout its major extent except ior predetermined frame areas left transparent and of a size and placement to register with said frame areas on the dial plate when the backing member is assembled therewith, and means for securing said plate and backing member in assembled relation.

NATHAN PRITIKIN.

REFERENCES CITED The followingreferences are of record in the le of this patent:

UNITD STATES PATENTS Number Name Date 250,028 Wiederer Nov. 22, 1881 1,320,524 Bachman Nov. 4, 1919 1,781,313 Blau Nov. ll, 1930 1,965,545 Foster July 3, 1934 2,117,442 McWeeny May 17, 1938 2,318,949 4 Kroner May 11, 1943 2,400,366 Murray May14, 1946

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