Abstract: An exercising apparatus utilizes an inclinable table over which is pivotably secured an arm. The arm is pivotably secured to the free end of a piston whose housing is otherwise pivotably secured to a frame to which the arm is secured. The cylinder has the uppermost chamber filled with oil and coupled to an oil receiving vented chamber by way of two parallel pads, each containing a check valve operable in opposed directions. Each path also contains a manually operable valve, one of which is disposed hydraulically in parallel with a valve containing selectably different size orifices. The lower chamber of the cylinder contains an elastic membrane which segregates the lower chamber into two separate compartments, the upper of which is filled with oil and the lower of which contains air. The operation of the cylinder simulates different weights and the effect of gravity thereon as if a user were actually lifting a barbell.

Abstract: Aluminum silicon alloys exhibiting microstructures characterized by the absence of any primary aluminum or primary silicon phase and a high volume fraction of finely dispersed eutectic silicon suitable for use as wear-resistant surfaces.