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586,214 · Basquin · "Vault-Light" · Page 2 Home  > Prism Glass  > Patent Index  > Page 2

586,214: 2 of 4

direction from which the light is to come and the line indicating the direction of the surface of the prism have been placed two dots in a line parallel to the direction of the receiving-surface and separated from each other by a distance equal to the arbitrarily determined width of the prism. In the case of this invention the object is to throw all of the light received from the predetermined direction upon the receiving-surface opposite a given prism, forward and as nearly as possible upon the line just below the next preceding prism. I therefore may lay off a line indicating one surface of such prism arbitrarily. I draw lines to indicate a large number of rays of light both entering and leaving the prism, those leaving the prism being converged upon the line immediately below the next preceding prism and those entering the prism being parallel to the determined direction. The undetermined face of the prism may now obviously be determined by laying down a number of short lines across these rays, which short lines are so positioned that the rays falling upon each are turned in the direction of the rays leaving such line, and by connecting these short surfaces in the proper manner to form a continuous surface the previously undetermined surface of the prism is established, and all the rays received upon the receiving-surface from the predetermined direction will by such a prism so formed be converged upon the line just below the next preceding prism, and will neither strike such preceding prism nor be directed appreciably below the same, and no two of such rays will be parallel to each other.     I have spoken of my invention as a "vault-light." It is more correctly described, however, as a "prism-tile," and I prefer to use that term.     I claim—     1. A vault-light comprising a receiving-surface adapted to be placed in an approximately horizontal plane, one or more projecting ribs or prisms on the opposite sides thereof, each prism having two converging surfaces, one for reflecting, the other for refracting the light, and one of said surfaces curved in such manner that substantially all of the light falling upon the surface of the vault-light will thereinto and be successively treated by the two surfaces of the prism, so that it is converged upon a line a little farther from the receiving-surface than is the lower edge of such prism and in advance of the lower edge of such prism by a distance substantially equal to the greatest width of such prism measured in the direction toward which the light is to be thrown.     2. A vault-light comprising a receiving-surface adapted to be placed in an approximately horizontal plane, one or more projecting ribs or prisms on the opposite sides thereof, each

prism having two converging surfaces, one for reflecting, the other for refracting the light, and both of said surfaces curved in such manner that substantially all of the light falling upon the surface of the vault-light will pass thereinto and be successively treated by the two surfaces of the prisms so that it is converged upon a line a little farther from the receiving-surface than is the lower edge of such prism, and in advance of the lower edge of such prism by a distance substantially equal to the greatest width of such prism measured in the direction toward which the light is to be thrown.     3. A prism-light comprising a substantially flat body of glass with a receiving-surface on one side, and one or more prisms on the other side, said prisms forwardly projecting at their lower extremities and having two converging surfaces, one of which is curved, the lower extremity of each of said prisms projecting in front of a line drawn through the forward upper extremity of said prism and substantially perpendicular to the receiving-surface, so that substantially all of the light falling upon the surface of the vault-light will pass thereinto and be successively treated by the two surfaces of the prism so that it is converged upon a line a little farther from the receiving-surface than is the lower edge of such prism and in advance of the lower edge of such prism by a distance substantially equal to the greatest width of such prism measured in the direction toward which the light is to be thrown.     4. A vault-light comprising a receiving-surface adapted to be placed in an approximately horizontal plane and provided with projecting ribs or prisms having each two converging surfaces, one for reflecting the light received, and the other for refracting the reflected light, the reflecting-surface being curved and the lower edge of such prism projecting forward of a line through the upper forward surface of such prism and substantially perpendicular to the receiving-surface, and the refracting-surface of such prism substantially parallel to the direction from which the light to he treated is to be received, so that substantially all of the light falling upon the surface of the vault-light will pass thereinto and be successively treated by the two surfaces of the prism so that it is converged upon a line a little farther from the receiving-surface than is the lower edge of such prism and in advance of the lower edge of such prism by a distance substantially equal to the greatest width of such prism measured in the direction toward which the light is to be thrown. OLIN H. BASQUIN. Witnesses:     DONALD M. CARTER,     FRANCIS W. PARKER.