US2096166A - Lens type reflector signal - Google Patents

Description

Oct. 19, 1937. J. E. ESHBAUGH ,096,

LENS TYPE REFLECTOR SIGNAL Filed June 7, 1935 3mm I Patented Oct. 19, 1937 UNITED STATES LENS TYPE REFLECTOR SIGNAL Jesse E. Eshbaugh, Flint, Mich, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application June 7, 1935, Serial No. 25,400

4 Claims.

This invention relates to auto-collimating devices and more particularly to this type of device which is used for highway signalling or for night advertising and is generally referred to 5 as the button type.

These devices have the property of reflecting light beams in the direction of incidence irre spective, within a certain range, of what that direction may be relative to the axis of the device.

This type of device has attained a wide usage in highway signs both for giving warning of curves and intersections and also for advertising purposes. There are of course practical limits to the variation of the angle of incidence from the axis of the device.

It is an object of my invention to provide an auto-collimating device with a wide incident beam angle.

It is a further object to provide such a having a high emciency of reflection.

It is a still further object to provide a simple, durable structure that will be aflected to a minimumby weathering.

For a better understanding of the nature and objects of my invention, reference is made to the following specification wherein there is described an embodiment of my invention which is illustrated in the accompanying drawing, in which;

Fig. i is an enlarged vertical section through so a device embodying my invention taken on the line il of Fig. 2.

Fig. 2 is a front elevation of the device.

Referring specifically to the drawing. a circular transparent plate, designated generally at 2, has a series of spherical raised buttons t on its outer face. These buttons may be arranged in anyoutline that may be desired or they may be arranged in letters to spell words so the circular ,Larrangement herein disclosed is merely illustra tive. Also on the rear face of the plateare a {second series of raised spherical buttons 6 whose axes coincide with the axes of the buttons 4 both buttons lying on the same line through the plate normal to its plane and forming lenses. Howdevice ever, as is evident from Fig. 1, the radii of the 'buttons A and 6 are not the same, that of the buttons i being greater. In, other words, the curvature of the surface of buttons 6 is less than the surface curvature of the buttons 4.

A shallow cylindrical reflector unit 8 surrounds the periphery of the plate when the two are in assembled relation. The lower portion of the reflector rim has a punched out notch Ill therein into which flts a positioning lobe l2 on the plate to accurately position the same within the reflector unit. The forward edge of the reflector unit is crimped inwardly as at M to secure the plate therein. An annular gasket [6 of any suitable deformable material is positioned between the plate and the crimped edge l4 toseal the joint against moisture which would otherwise attack and tarnish the reflector. The rear or reflecting surface of the reflector has pressed out or dish shaped portions E8 of substantially the same shape and size as the buttons 6, the axes of which are coincident with those of the buttons. The inner concave surfaces of these portions are highly polished and act as reflectors, the surfaces of the buttons 6 and the reflectors being spaced apart an equal distance throughout.

On the 'rear face of the plate is cast an ann ar raised ring 20 which contacts with the inner surface of the reflector unit to accurately maintain the correct focal distance of the reflecting surfaces. It will be evident therefore that this subassembly of the plate and reflector is a complete moisture proof unit in itself with fixed focal distances.

A circular drum shaped casing houses the subassembly. This casing is formed of two parts 22 and 24 which form the back and front respectively. The edges of the two are flanged and crimped as shown at 26 to secure the two together and two diametrically opposite side portions-are elongated to form ears 28. having holes 30 therein for supporting means. The forward circular face of the casing has a series of circular openings 32 therein through which the spherical buttons 4 project, the strips between the openings lying flat against the front of the plate in assembled position. The rear face of the casing has a circular raised ridge 34 pressed therein which acts to position one end of a helical spring 36 the opposite end of the spring resting against the rear face of the reflector assembly adjacent the raised annular ring 20 and keeping the reflector tightly in contact with the plate at this point, pressing the plate and reflector assembly tightly against the front of the casing and also dampening the blows to which the plate might be subjected, decreasing the possibility of lens breakage.

The paths of several light rays are shown in Fig.

1 as they impinge upon the lenses and then are refracted and reflected back again. The rays shown strike the buttons 4 at various angles from the horizontal axis of the plate up to 30, which is approximately the limit. It is-clear that in all the examples shown the light ray is not reflected directly back along the path of incidence but in a parallel path spaced at a short distance therefrom. The spread, or the distance between the incident and reflected rays, depends entirely on where and at what angle the incident ray strikes the button 4. The ray A has the least spread since it strikes the button 4 normal to its surface and extends through the center, retracting slightly to the reflector. The ray B has the most spread and it strikes the surface of button 4 at an angle of about 30. I

It will thus be evident that I have provided an auto-collimating device which is effective through a considerable angle from the axis thereof, and has a complete sub-assembly unit that is sealed from the weather and that means are provided to accurately locate the lenses with respectto the reflecting surface at all times.

I claim: a

1. In a light reflecting device, a transparent plate having a plurality of spaced spherical light concentrating portions on .each face aligned in pairs and forming lenses, a reflector adapted to be secured thereto having a plurality of reflecting surfaces aligned with and curved similarly to the concentrating portions for cooperation therewith, means forming a moisture-proof Joint securing the two together, a casing for the whole,

the front wall of which has a plurality of openings therein and through which the spherical portions on the front face of the plate are adapted to project and resilient means actingagainst the central portion of the rear wall of the casing and the rear of the reflector to seat the plate against the front wall of the casing with the spherical portions projecting through said openings.

2. In an autocollimating device, a transparent plate, a series of buttons on the front face of the plate, integral projecting spacing means on the rear face thereof near the center, a reflector secured to the plate by having its periphery flanged therearound, said reflector bearing against the spacing means, a casing in which the plate andreflector are carried, said casing having openings in the front wall aligned with and fitted to sale buttons and resilient means between the reflector and the rear wall of the casing to seat the plate against the casing front wall and bearing on the reflector adjacent the spacing meana 3. In an autocollimating device, a transparent plate having raised spaced light concentrating portions on the rear face thereof, integral projecting spacing means on the rear face of the plate among the concentrating portions, a reflector having concave portions opposite the concentrating portions secured to the plate, portions of the reflector among the concave portions hearing against the spacing means, a casing surrounding the plate and reflector, said casing having openings aligned with said concentrating portions and resilient means bearing against the inner surface of the casing and the rear face of the reflector opposite its point of contact with the spacing means to maintain the plate and reflector in snug relation to each other and to the casing.

4. In an autocollimating device, a transparent plate having a series of spaced light concentrating portions on the rear face thereof. a circular raised annular ring on the rear face of the plate among the concentrating portions, a reflector secured to the plate having a plurality of concave portions in alignment with the concentrating portions and contacting the spacing ring among the concave portions to space the reflecting surfaces from the plate, a casing around the plate and reflector having apertures in alignment and cooperating with the concentrating portions, an annular raised ring in the rear casingface in alignment with the annular spacing ring on the plate but of larger diameter and a spring between the casing and reflector having its base within the annular ring on the casing and bearing on the reflector opposite the spacing ring.

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