Improvements in curved surface light reflecting ornaments
Реферат: 548,834. Cellulose derivative compositions and articles synthetic resins. MEYER, M. C. April 23, 1941, No. 5271.. Convention date, June 12, 1940. Drawings to Specification. [Classes 2 (ii) and 2 (iii)] [Also in Groups VII and XXIII] An ornamental object is produced by orienting faceted light-reflecting media such as pearl essence in a plastic body, as described in Specifications 243,558 and 247,717, [both in Class 70], the object having a curved surface comprising at least a first and second surface area, the faceted light-reflecting particles in the first area being generally parallel to the surface so that light is strongly reflected, and the particles in the second area being inclined to the direction of the surface so that substantially no light is reflected. The plastics may include resins, such as polymethacrylates and acrylates, formaldehyde condensation products and vinyl compounds, and cellulosic derivatives including cellulose esters such as cellulose nitrate and acetate and cellulose ethers such as ethyl and benzyl cellulose. Polymethyl methacrylate sold under the trade name " Lucite " is especially suitable because of its index of refraction of about 1.5, its excellent transmission of light and its low light absorption. A mix is formed comprising the monomer of methyl methacrylate and a dye previously prepared so as to be miscible therewith, and to this mix is added pearl essence. The liquid is poured into a mould of circular cross section. The monomer is then completely polymerized to solid form, the orientation of the particles being effected during the polymerization and the particles being set in their properly oriented positions concentric to the long axis of the cylinder. In using other mouldable materials the orientation may be effected by extrusion, stretching or electrical means. For use in rings, brooches, studs and the like, the plastic is cut en cabochon so that the area where the particles lie substantially parallel extends centrally over the periphery of the object with two dark areas at the sides. Necklaces are bored through the original axis of the rod, so that the band of light reflecting surface is concentric around the cord on which the spheres are threaded. Metallic faceted particles, faceted pigments or light reflecting media with faceted surfaces generally, may be substituted for the pearl essence.
Improvements in or relating to lap truing or other machines for generating curved surfaces
Номер патента: GB596099A. Автор: . Владелец: American Optical Corp. Дата публикации: 1947-12-29.