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D30,144 · Jacobs · "Design for a Lens or Glass for Gratings" · Page 1 Home  > Prism Glass  > Patent Index  > Page 1

D30,144: 1 of 2

Patents: 481 of 530	UNITED STATES PATENT OFFICE JACOB JACOBS, NEW YORK, N. Y. DESIGN FOR A LENS OR GLASS FOR GRATINGS.	Jacob Jacobs 54 of 57
SPECIFICATION forming part of Design No. 30,144, dated February 7, 1899. Application filed December 21, 1898. Serial No. 699,972. Term of patent 14 years.

To all whom it may concern:     Be it known that I, JACOB JACOBS, of New York city, in the county of New York, and in the State of New York, have invented and produced a certain new and original Design for a Lens or Glass for Gratings; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, in which—     Figure 1 is a perspective view of a lens or glass embodying my design, and Fig. 2 is a cross-section of the same.     Letters of like name and kind refer to like parts in each of the figures.     The object of my invention is to provide a design for lenses or glasses for illuminating-gratings; and to this end said invention consists in the design for a lens or glass substantially as hereinafter specified.     The leading feature of my design consists in the shape or configuration, which comprises a plate from one side of which project two parallel ribs, each of which in cross-section is tapering from its place of connection with the plate and has one face curved convexly and the opposite face in the case of one rib plane and in the case of the other rib

plane for a portion of the surface and slightly curved convexly for the remainder and one rib projecting considerably less from the plate than the other.     In the drawings, A designates the plate, and B and C, respectively, the two tapering ribs that project therefrom parallel with each other. The rib B is the smaller one—that is, it projects much less from the plate than the rib C—and its face or side next the rib C is convexly rounded, while its opposite face or side is plane. The face or side of the rib C next the rib B has a portion of its surface plane and a portion curved convexly, the latter extending from the apex of the rib. The opposite face of said rib C is curved convexly.     Having thus described my invention, what I claim is—     The design for a glass, for gratings, substantially as herein shown and described.     In testimony that I claim the foregoing I have hereunto set my hand this 19th day of December, 1898. JACOB JACOBS. Witnesses:     JOHN P. WHELAN,     ALEX SMEDES.