JACOB J CRESKOFF
Engineers in Penn Wynne, PA

4167549, Sep 11, 1979

Mar 11, 1974

5/450119

Jacob J. Creskoff - Wynnewood PA

B28B 150

264 42

A parting agent for molds used in forming concrete and method of use comprising an effective amount of an acid, an agent which reacts with free alkali in the cement of the concrete mix to form a multitude of tiny bubbles and a vehicle therefor. The preferred embodiment of the invention includes a weak acid, such as tannic acid, form oil as the vehicle and Vinsol-Resin as the bubble forming agent. The term "Vinsol" will be used herein as a short version for Vinsol-Resin. The method of use comprises applying a coating of the parting agent to the inner surface of a mold and then delivering a sufficient quantity of concrete mix into the mold, completing the formation (curing) of the concrete in the mold, and then removing the cured concrete (casting). The weak acid in the parting agent neutralizes the free alkali in the cement component of the concrete to prevent the formation of a bond between the concrete casting and the mold surface. The "Vinsol" in the parting agent creates air bubbles at the contacting surfaces of the mold and the concrete casting.

4166648, Sep 4, 1979

Sep 26, 1977

5/836788

Jacob J. Creskoff - Wynnewood PA

B66C 102

294 64R

A vacuum lifting apparatus is disclosed for lifting large, heavy objects, wherein the lifting surface of the object deviates somewhat from a planar configuration as in the case of manufacturing deficiencies or where the object is of a flexible nature. A frame has opposed surfaces with a generally peripheral deformable closed-cell resilient gasket partially secured to one surface of the frame along the inner peripheral portions of the gasket in an endless arrangement which defines an open chamber with the frame. A source of reduced atmospheric pressure such as a vacuum pump, selectively communicates with the chamber through a valve, such that positioning the gasket member against the object and drawing a vacuum in the chamber thus creates an atmospheric grip between the frame and the object whereby the object may be lifted by lifting the frame. If the lifting surface is inaccurate, or when the object flexes and assumes a curbed configuration, the partial attachment of the gasket thus permits the gasket to decompress and to flex in accordance with the curvature of the object, thereby maintaining the vacuum within the chamber.