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D27,490 · Jacobs · "Design for a Lens for Gratings" · Page 1 Home > Prism Glass > Patent Index > Page 1 |
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To all whom it may concern: Be it known that I, JACOB JACOBS, of Brooklyn, in the county of Kings and in the State of New York, have invented a certain new and original Design for Lens for Illuminating-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 embodying my design, and Fig. 2 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 for illuminating-gratings; and to this end said invention consists in the design for a lens, substantially as hereinafter set forth. The leading feature of my design is a plate with one surface plane and its opposite surface provided with two parallel ribs that are triangular in cross-section, the opposite sides |
of each rib being inclined relative to the plane of the plate and the
apex of one rib being a less distance from the plate than the apex of
the other. The lens consists of a plate A with one face plane and two straight parallel ribs or projections B and C on its opposite face, each of said ribs being triangular in cross section with both sides of each inclined with relation to the plate A, and the apex of the rib B being a less distance from the plate than the apex of the other. Having thus described my invention, what I claim is— The design for a lens, substantially as set forth. In testimony that I claim the foregoing I have hereunto set my hand this 7th day of May, 1597.
JAS. E. HUTCHINSON, CHAS. J. WILLIAMSON. |