US2236940A - Electric lamp guard - Google Patents

Description

April 1, 1941. J. R. FOLEY ELECTRIC LAMP GUARD 4 Sheets-Sheet 1 4/0/70 ff. fJ/ey Filed Oct. 31, 1936 April 1, 1941. I J FOLEY I 2,236,940

ELECTRIC LAMP GUARD Filed ot. 31, 1956 4 Sheets-Sheet 2 April 1, 1941. R, FOLEY ELECTRIC LAMP GUARD- Filed Oct. 31, 1936 4 Sheets-Sheet 3 April 1,1941. J FQLEY 2,236,940

ELECTRIC LAMP GUARD Filed 001:. 31, 1936 4 Sheets-Sheet 4 swam/tor,

W W W" Patented Apr. 1, 1941 ELECTRIC LAMIP GUARD John R. Foley, New York, N. Y., assignor to Marjorie Hart, New York, N. Y.

Application October 31, 1936, Serial No. 108,656

3 Claims.

This invention relates to electric lamp guards and more particularly to a safety lamp guard for use especially in working around high tension wire or the like. The guard was designed for hand or hanging use and is of special value in confined spaces or when in proximity to high tension voltage; either in conductors or generators.

The primary object of the invention is to provide an electric lamp guard and holder made entirely of insulating material so that it will not only protect the user, but cannot conduct electricity should it be brought into contact with conductors, generators or the like.

A further object is to provide an insulated guard which is transparent and/or translucent to obtain full benefit of light rays and yet so constructed as to eliminate glare.

Another object is to supply a lamp guard designed to produce insulation for the user in so much as its structure is absolutely without any metal or other conducting material so that it will insulate against short circuit or other electrical contamination, especially when used in confined spaces.

A still further object is to furnish a lamp guard of transparent and/or translucent material having high. dielectric strength and one which will permit maximum illumination without glare or danger of shock.'

With the foregoing objects outlined and with other objects in View which will appear as the description proceeds, the invention consists in the novel features hereinafter described in detail in connection with the accompanying drawings and more particularly pointed out in the appended claims.

In the drawings:

Fig. l is a side elevation of one form of the guard comprising separable sections.

Figs. 2 and 3 are horizontal sectional views taken on the lines 22 and 3i3 respectively of Fig. 1.

Fig. 4 is a longitudinal sectional view on the line 4-4 of Fig. 1.

' Figs. 5 and 6 are horizontal sectional views of a modification in which the sections are hingedly connected.

Referring first to the embodiment of the invention illustrated in. Figs. 1 to 4 inclusive, 1 designates a tubular holder or handle, which is provided at one end with an annular flange 8 and a sleeve 9, the latter being provided with a longitudinal external groove Ill. A half collar H projects from the sleeve, and the groove extends on to the half collar and merges into a peripherally extending groove I2. A slidable and rotatable ring I 3 surrounds the half collar and is provided with an internal lug M which cooperates with the grooves so as to form a bayonetjoint.

An inner segmental plate i5 is rigidly united with the half collar and is fixedly connected. to the inner ends of spaced strips It; the outer ends of these strips being secured together by an outer segmental end plate IT.

The parts I5, l6 and I1 form one section of a cage or guard and this section cooperates with a similar section formed of an inner segmental plate i8, longitudinal srips i9 and an outer segmental plate 29. The last mentioned section is provided with a half collar '2! which is fixed to the plate H3 and cooperates wih the ring !3 in holding the two sections together.

The strips i6 and I9 may be of any suitable shape, for example they may be relatively thin with their narrow edges facing inwardly and outwardly. This particular shape, if low melting point material is employed, prevents the heat of the enclosed lamp 22 from concentrating upon any broad surfaces and also permits ample ventilation so that thermoplastic dielectric material having a relatively low melting point may be used in manufacturing the guard. For further ventilation the segmental plates l5 and I8 are provided with apertures 23.

In order to secure the outer ends of the sections together one section is provided with a dovetail opening 24 and the other has a correspondingly shaped key 25 which fits in the opening. A plate 26 is fixedly secured to the segmental plate I? and overlaps the dovetail joint in order to hold the key in the opening.

For ventilating purposes the segmental plates I7 and 29 are provided with relatively large apertures 21 and 28.

To prevent the glare from the lamp interfering with those using the guard, at number of the strips 16 are provided with thickened portions 29 which give the strips a wedge shape cross section for portions of their lengths. These thickened portions may be of any suitable length, for in.- stance, the central one of these thickened portions may be of greatest length and the others graduate downwardly from this length in order to allow proper illumination with a minimum of glare.

It will be obvious from the foregoing that when the ring 13 is turned in the proper direction and then moved into contact with the flange 8, the section comprising the parts l8, I9, 20, 2|, can

be readily removed for the changing or removal of the lamp bulb 22.

Instead of making the guard of separable sections it can be made of hinged sections as shown in Figs. and 6, so that losing or misplacement of a section will be prevented.

Referring now to the last-mentioned figures, the section formed by the parts l5a, Ilia and Ila is hingedly connected as shown at 39a to the inner and outer segmental plates l8a and 20a of the other section, which also has strips l9a. 1

As best shown in Fig. 6, the outer segmental .plates are provided with relatively large ventilating openings 21a and 28a.

In order to limit the opening of the sections, the plate I 8a is provided with a. fixed arm 3la which cooperates with a stop 32a on the plate IIa.

A bayonet joint [2a, [4a, may be employed in this embodiment to lock the hinged sections .to-

gether.

In this embodiment of the invention certain of the strips lBa are made of wedge shape with the wedge pointed inwardly (like in the first embodiment) so as to take care of glare without surfaces which would tend .to become heated due to radiation from the lamp.

The entire guard in each instance is made of any suitable thermoplastic insulating material, but in order to furnish maximum illumination, such material is preferably transparent and/or translucent. The parts of the guard may be cast or the guard may be made up from a number of small parts secured together by cement of the same or other insulating material. I have manufactured these guards from "Plastacele which is cellulose acetate free of nitrate and camphor,

and I have used acetone as a welding agent to secure the parts together.

From the foregoing it will be .understood that I have produced an improved guard of a transparent material having dielectric strength; constructed and designed with atotalabsenceof metal or other conducting material; also constructed of material with limited heat resistance due to the ventilating features of the design.

While I have disclosed preferable embodiments of my invention, I am aware that changes may be made in the details disclosed without departing from the spirit of the invention as expressed in the claims.

What I claim and desire to secure by Letters Patentis:

l. A lamp guard formed entirely of a dielectric and comprising segmental end plates joined together by spaced narrow strips, said strips forming an annular wall, portions of some of said strips being substantially wedge shape in cross section and forminga glare shield.

2. An electric la-mp guard formed entirely of a thermoplastic dielectric and comprising a series of spaced narrow strips forming an annular wall, said strips having relatively narrow edges facing the center of the guard, some of said strips having substantially Wedge shape portions forming a glare shield.

3. An electric lamp guard formed entirely of a thermoplastic dielectric and comprising a series of substantially flat narrow strips forming an annular wall, said strips having relatively narrow edges facing the center of the guard, some of said strips having substantially wedge shape .portions forming a glare shield, the strips being formed of transparent material.

JOHN R. FOLEY.

Images