Abstract: A backlit display sign includes a rear sign enclosure element at the back of the sign with a forwardly facing wide mouth opening. Extending across the mouth opening is a front sign element or cover formed from an optically transmissive light guide which extends laterally across the mouth opening of the display. Light diffusing (scattering) reflective layers on the front and rear surfaces of the guide or within the guide itself make the guide a light propagation sustaining channel that serves to funnel light rays laterally and forwardly within itself to an image-producing opening where the light is allowed to be emitted for producing the image of a symbol, letter, number or other indicia that is visible on the front of the display. A light cavity between the front cover and the rear sign enclosure element contains at least one illuminating device, e.g. a light emitting diode (LED), to provide visible illumination that is transmitted from within the light cavity through the guide to the front of the sign.

Abstract: A backlit display sign includes a rear sign enclosure element at the back of the sign with a forwardly facing wide mouth opening. Extending across the mouth opening is a front sign element or cover formed from an optically transmissive light guide which extends laterally across the mouth opening of the display. Light diffusing (scattering) reflective layers on the front and rear surfaces of the guide or within the guide itself make the guide a light propagation sustaining channel that serves to funnel light rays laterally and forwardly within itself to an image-producing opening where the light is allowed to be emitted for producing the image of a symbol, letter, number or other indicia that is visible on the front of the display. A light cavity between the front cover and the rear sign enclosure element contains at least one illuminating device, e.g. a light emitting diode (LED), to provide visible illumination that is transmitted from within the light cavity through the guide to the front of the sign.

Abstract: A casting riser including a top support member and an internal support member to receive the high pressure molding forces to enable the casting riser to withstand the high pressure molding forces.

Abstract: An improved casting riser is provided of two different materials, an upper portion having a low thermal conductivity for retaining the heat of the metal in the riser liner and a lower portion having a high thermal conductivity to allow transfer of heat between the molten metal in the riser liner and the molten metal in the mold.

Abstract: A two-part mold insert for forming a riser in a sand mold with the insert having a breakable thin collar and a cellular riser material which is compressible and gasible so that hot metal dissolves the cellular riser material but not the collar which prevents molding sand from falling into the mold during the gasification of cellular riser material.

Abstract: A process by which a complex shape of a sand core is reproduced in a metal plate which is made to the exact size of the sand core through a double casting process using different materials.