Up: Patent Index

432,249 · Sharts · "Concrete Illuminating-Tile" · Page 2 Home  > Prism Glass  > Patent Index  > Page 2

432,249: 2 of 3

it will form an ample and sufficient bearing for the lenses and obviate entirely the necessity of any direct bearing of the lenses upon the grating. The sides of these lenses may be made of any irregular shape sufficient to allow the plastic cement filling to adjust itself firmly around the lenses for the purpose above stated.     The wearing-surface of my illuminating-tile is composed of the concrete filling flush with the surface of the glass lenses. I do not claim this as part of my invention at this time, as it was covered by a patent granted to me April 22, 1873; nor do I claim any particular shape for the irregular sides of the glass lenses.     My invention consists in the following elements: First, the equal area and diameter through the light-openings of the gratings with the top surface of the lenses; second, the lenses being of equal diameter and area both on the top and bottom surfaces; third, the lenses extending through the grating or even below if required, and, fourth, the lenses having irregular sides, which, being embedded in the concrete filling, require no other bearing than the concrete filling itself. The glass lenses thus being firmly embedded in the concrete filling and the concrete filling resting compactly

upon every portion of the bed-plate around the light-openings, the whole forms a solid and substantial structure suitable for the purpose for which it is required.     By the use of my invention an important desideratum is accomplished, an increase of twenty-five per cent. of the volume of light passing through the lenses and light-openings of the gratings, supposing the lenses to be two inches in diameter, a matter of great benefit and economy to users of vault-lights.     As the devices I have herein described may be practically available to other styles of illuminating-tiles, I do not confine myself to the concrete tiles only.     Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is--     An illuminating-tile composed of a plate perforated for light-openings, lenses set therein, each lens being of cylindrical form with a V-shaped projection encircling its central portion and embedded in the cement filling, thereby interlocking the parts, substantially as set forth. THEODORE SHARTS. Witnesses:     G. W. GOODWIN,     WM. B. DAVIS.