US394260A - Pavement and floor light - Google Patents

Description

(No Model.)

J. C. FRENCH.

PAVEMENT AND FLOOR LIGHT.

No. 394,260. Patented Deo. 11, 1888.

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UNITED STATES PATENT EFICE.

JAMES C. FRENCH, OF BROOKLYN, NEv YORK.

PAVEMENT AND FLOOR LIGHT.

SPECIFICATION forming part of Letters Patent No. 394,260, dated December 11, 1888.

Application filed .Tune Z3, 1888. Serial No.277,94l. l(No model.)

T0 all whom t may con/007%:

Bc it known that I, JAMES C. FRENCH, of Brooklyn, in the county of Kings and State of New York, have invented a new and useful Improvement in Pavement and Floor Lights, of which the following is a specification.

My invention relates to glazed pavements and floors through which light is admitted to vaults or apartments beneath, and in which pieces of glass called lenses are placed upon a cast-iron grating, bed-plate, or frame over openings therein and are bedded in cement thereon.

I will describe in detail a pavement or floor light embodying my improvement, and then point out the novel features in claims.

Figure l represents a plan view of a portion of a pavement-light embodying my improvement. Fig. 2 represents a vertical section of same on the line 0c .fc of Fig. l. Fig. 3 represents a face view ot a sheet of metal which may be ben t into the form of a taper ring or casing for inclosing the elastic cement.

Like letters of reference indicate corresponding parts in all the figures.

A represents a perforated plate or grating for a pavement or iioor light suitable for vault, sidewalk, iioor, root, or wherever a light transmitting pavement or iioor may be required.

B indicates the apertures, perforations, or holes through the bed-plate for the downward passage of light. The line :t being drawn through the centers of adjacent holes orperforations B, is the line of least strength, the metal of the plate between the holes being wider, and consequently stronger, everywhere else than on that or other lines connecting centers of adjacent holes B. To strengthen these weak places of the bed-plate, I form between each hole B and every adjacent hole B over the weak place between the two a strengthening-rib, o, every one of which ribs is isolated from every other one, extending onlya short distance on each side of the place it is intended to strengthen. lVere the several isolated ribs a extended each way until they met and united at points b, Fig. l, they would then together constitute continuous and connected ribs of a form in common usc, but which would consist in part of a useless body of metal, considerably increasing the weight without adding to the strength of the weakest parts of the bed-plate.

C are the lenses or pieces of glass covering the holes l-. The lenses C have hitherto been made with vertical sides, and therefore liable to be easily loosened or displaced from their bed in the body of cement, D, which cement is represented in the ligures as covering a part only of the piece of bed-plate therein represented. To prevent such loosening or displacement ot' the lenses, I make the lenses C taper or smaller on the top or upper face than on the bottom or lower tace. Being tapering, the lenses, if once embedded in the cement, D, cannot bc removed without first breaking out and removing a portion of the surrounding cement.

To allow for the expansion and contraction of the lenses in accordance with the changes of temperature to which they may be exposed, I provide a surrounding annular coating, of an elastic cement, which maybe economically made of a combination of sulphur and coal-tar, and I incase this elastic ring or coating with a ring of thin metal having the same taper as the lenses and as the elastic coating which surrounds them. In order that the body of cement, D, may entirely cover and hide from view the ribs a, the rings or coatings c, and rings or casinps d, the lenses C project considerably above the ribs a and a short distance above the tubes c and d. This difference in height between the lenses and tubes may be about one-sixteenth of an inch. If the dii'i'erence is too much, when an adjacent portion of the cement, D, is dislodged the edges of the glass will be exposed and liable to injury; if too little, the ends of the tubes will be liable to become exposed to view. To prevent injury to the lenses when an adjacent portion of the cement, D,is dislodged from around it, I taper or bevel the upper outer edges of the lenses toward the center above the tops of the tubes, as represented in the drawings at h. The ribs d serve also to guide the lenses to their seats and retain them thereon before the cement, D, is spread, and they also serve to penetrate and hold the cement.

To prepare the pavement or floor light for IOO use, the bed-plate is irst placed in position. Next the lenses, surrounded by the ring coatings of flexible cement and incased in the taper metallic rings, are placed over the holes in the bed. Then a cement which becomes hard and unyielding when set-preferably what is known as concrete, made of Portland cement and sand-is spread all over the face of the bed-plate, covering the. ribs and tubes and iilling the space between them full and filling in flush between the upper eX- posed edges of the lenses, so that the finished surface of the cement may be flush and even with the upper surfaces of the lenses.

In one end of the sheet of metal d (represented in Fig. 3) is a slit or transverse hole, e, and on the other end of the same sheet of metal is a projecting' tongue, f. Vhen the sheet d is bent into the form of a taper ring or casing, d, the tongue f may be passed through the slit e and bent over and clinched to fasten the ends of the sheet together.

Vhat I claim as new, and desire to secure by Letters Patent, is-

1. In a pavement or floor light, the combination, with a perforated bed-plate or grating having upwardly-projecting strengtheningribs, of tapered lenses having their larger ends downward, covering' the perforations in the bed-plate, metallic rings surrounding said lenses at a distance therefrom and tapered to substantially correspond with the taper of the lenses, and annular bodies of elastic cement interposed between the lenses and the said metallic rings, providing for the expansion of the lenses and tapered to correspond to the` taper of the rings and lenses, the said lenses, elastic cement, and metallic rings resting upon the upper face of the bed-plate, and a body of hard cement spread upon the upper face of the bed-plate between the said metallic rings and ribs and covering the said ribs, and by which hard cement the lenses, elastic cement, and metallic rings are all firmly held in posirion, substantially as described and set forth.

2. In a pavement or floor light, the combination, with a perforated bed-plate or grating having upwardly-projecting strengtheningribs, of tapering lenses havingtheir larO'er ends resting upon the upper face of the bed-plate and covering the holes therein, metallic rings surrounding the said lenses at a distance therefrom and tapered to substantially correspond to the taper of the lenses, and annular bodies of elastic cement interposed between the lenses and said rings and tapered to correspond to the taper of the rings and lenses,

the said elastic cement and metallic rings terminating at their tops a distance below the tops of the lenses, and a body of hard cement spread upon the upper face of the bed-plate between the metallic rings, covering the metallic rings and elastic cement, and also covering the strengthening-ribs, whereby only the upper surfaces of the lenses and of the body of hard cement are exposed to view, all substantially as described and set forth.

JAMES C. FRENCH.

Vitnesses:

FREDK. I-IAYNES, JOSEPH W. ROE.

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