Abstract: Solid energetic compositions are prepared from powdered solid components such as metallic aluminum fuel and liquid oxidizers by forming a coating of polyvinyl alcohol over the powdered solid by precipitation from a solution of polyvinyl acetate, and combining the coated particles with liquid oxidizer which will permeate and swell the particle coating, causing the particles to agglomerate into a solid rubbery mass.

Abstract: Rocket motors are constructed by encasing a solid porous poly(vinyl alcohol) core in the shape of the propellant grain with motor casing material in the same manner as motor casing material is conventionally applied over a disposable or removable mandrel. The motor is then completed by filling the open passages of the core with liquid oxidizer. When the liquid oxidizer permeates the poly(vinyl alcohol), the result is a solid continuous propellant grain of rubbery consistency. Aluminum powder may be incorporated in either the porous poly(vinyl alcohol) or the liquid oxidizer to achieve a fuel-enhanced propellant.

Abstract: A drilling jar to be installed in a set of drill collars in a drill string is disclosed. In the illustrated embodiment, first and second tubular members telescope relative to one another. At the upper end of the lower tubular member, a set of protruding lugs match shoulders having undercuts which permit relative rotation of the two tubular members through part of a turn, thereby permitting the two members to axially telescope whereby locking or unlocking the telescoping movement is controlled. The lower tubular member has an upwardly facing shoulder which is abutted against the lower end of the upper tubular member. This permits the two to be reciprocated and banged together to create a jar for the drill string. A dual jarring activity is developed by a cam actuated radially yieldable collet-type release mechanism that allows relative linear movement of the tubular members and permits selected jarring activity independently of or in conjunction with the lugged locking and releasing portions thereof.

Abstract: A drilling jar to be installed in a set of drill collars in a drill string is disclosed. In the illustrated embodiment, first and second tubular members telescope relative to one another. At the upper end of the lower tubular member, a set of protruding lugs match shoulders having undercuts which permit relative rotation of the two tubular members through part of a turn, thereby permitting the two members to axially telescope whereby locking or unlocking the telescoping movement is controlled. The lower tubular member has an upwardly facing shoulder which is abutted against the lower end of the upper tubular member. This permits the two to be reciprocated and banged together to create a jar for the drill string. When the string is jarred, the drill string can be jarred loose. the apparatus further includes a packer around a pipe positioned in the upper end of the upper tubular member.