Abstract: A baseball practice device in which a baseball is releasably attached to a "Y" shaped tether system which, in turn, is supported by two horizontal arms arranged in a "Y" shaped configuration. The combination of the horizontal arms and the tether system allows simulation of a pitching environment where the baseball may be presented to the batter with a uniform and repeatable flight path to enhance batting practice.

Abstract: A pressure transducer for measuring the pressure of a fluid comprising a housing having a cavity. A diaphragm capable of displacement is located within the cavity, dividing the cavity into a first and second chamber. The first chamber is capable of receiving a fluid to be measured, typically a liquid or a gas, while the second chamber contains a liquid such as a silicon oil. The second chamber also contains a gas and means for measuring the displacement of the diaphragm. Upon pressure being exerted against the diaphragm from the fluid, the diaphragm displaces against the liquid and gas, compressing and dissolving the gas as pressure is increased. Displacement of the diaphragm is measured by a measuring device, such as a strain gauge. When the gas is fully dissolved, further movement of the diaphragm is limited by the compressibility of the liquid.

Abstract: This invention is concerned with permutation locks having a wheel pack comprising a plurality of rotatable permutation discs, each having a recess which must be correctly aligned before the bolt of the lock can be withdrawn. One known method for determining the positions of the permutation discs is by analysis of X-radiation which has passed through the wheel pack parallel to the axis of rotation of the discs. In locks according to this invention, the opacity of the wheel pack to penetrating electromagnetic radiation along any line parallel to the axis of rotation of the discs is independent of their orientation.