Abstract: A method of removing a core from a molded product in which the core is formed of a particulate inert material, such as sand, bound together by a cured binder of a water soluble carbohydrate alone or mixed with a silicate is disclosed. The silicate is preferably an alkali earth metal silicate, preferably sodium silicate, and the carbohydrate is preferably a saccharide or starch. The binder is cured by heat. The core and molded product are exposed to water, preferably heated water in a bath or steam, to rapidly disintegrate the core and remove it from the molded product.

Abstract: Disclosed is a shield for protecting the eyes and at least the upper half or more of the face of the wearer and comprises a head-encircling element having a frontal part of relatively rigid material provided with oppositely extending wings for receiving pockets on a headband. The frontal part is configured to conform to the brow of the wearer and a compatibly configured frame is mounted on the frontal part by a transverse hinge. A protective screen of transparent nature depends from the frame in a protective mode and, because of the hinge, can be swung forwardly and upwardly away from and downwardly and rearwardly back to the protective mode. The screen may be removed from the frame and the headband from the frontal part for laundering, sterilizing, etc.

Abstract: The utility of a cover for vents or drains is improved by having a unitary, integral fastening means which can be used to either secure the covering so securely that mutilation of the cover may be required to remove the cover or that the cover may be easily removed and replaced. The cover can be formed from any polymer with any desired surface configuration, i.e., hole size and shape, and can be used to modify existing covers or as the original cover for a hole or vent. The fastening means when integral is made of the same material as the cover and can be easily expanded and secured by pressure elements. Since the normal sleeve has been replaced by the integral fastener which is part of the cover, no relative rotation of the sleeve and pressure means can occur.

Abstract: A marine propeller possessing several features; e.g., one-piece cast or molded construction which in one embodiment preferably of the invention is a plastic of the class including polyester; an improved center or core structure in the form of a nave or barrel having an annular wall concentrically surrounding a power-shaft-receiving hub joined to the annular wall by relatively thin spokes configured as vanes functioning as an interior turbine. Propeller blades are joined to and project radially from the exterior of the nave in typical fashion.

Abstract: A method of removing a core from a molded product in which the core is formed of a particulate inert material, such as .[.sand-bound.]. .Iadd.sand, bound .Iaddend.together by a cured binder of a water soluble carbohydrate alone or mixed with a silicate is disclosed. The silicate is preferably an alkali earth metal silicate, preferably sodium silicate, and the carbohydrate is preferably a saccharide or starch. The binder is cured by heat. The core and molded product are exposed to water, preferably heated water in a bath or steam, to rapidly disintegrate the core and remove it from the molded product.