Up: Patent Index

410,380 · Ross · "Vault-Light" · Page 2 Home  > Prism Glass  > Patent Index  > Page 2

410,380: 2 of 3

portions thereof which are not provided with the projections B' will come opposite the reentrant portions of the bed-plate A, which would otherwise so diminish the diameter of the light-hole as to prevent insertion of the glass, and when so turned the glass may be placed in position in the hole, notwithstanding the irregularity of this latter, so as to rest properly upon the flange or ledge a' and have a lateral bearing all around. It will thus be seen that the expensive operation of truing the holes is done away with, thereby considerably reducing the cost of the article.     The advantage of having the glass fit properly within the bed-plate and frame, so as to have a downward bearing and a lateral bearing upon the iron of which it is composed, lies in the fact that in this position the force of any blows coming upon the glass is resisted by the iron and not by the cement, which latter would chip or crumble under such blows, and would soon loosen the glass, causing it to become displaced or giving rise to a leakage in the vault-cover. These advantages are of course obtained without any increase of expense by the construction which I have devised.     It is obvious that various modifications in the details of construction may be made without departing from the principle of my

invention, and I therefore do not wish to be understood as limiting myself strictly to the precise details hereinbefore described, and shown in the drawings.     Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is--     1. The combination, with the bed-plate A, having light-hole a, provided with circular ledge or flange a', of the glass B, having a body portion of less diameter than the main diameter of the light-hole, but greater than its contracted diameter, said glass being provided at its margin with radial projections to bear against the side wall of the light-hole, substantially as and for the purposes specified.     2. The combination, with the bed-plate A, having light-hole a, with flange or ledge a', of the glass B, having a body portion of a diameter less than the main diameter of the light-hole a, but greater than its reduced diameter, said body portion being provided with radial projections B', to bear against the side wall of the light-hole, and shoulder b, and the filling D, of cement or the like, substantially as and for the purposes specified. CHRISTIAN H. ROSS. Witnesses:     ALICE MCIVER,     IRVINE MILLER.