Abstract: A method and apparatus for control of pivoting machine members propelled by linear actuators so as to permit coordinated motion of the pivoting members with translating machine members. Position commands for the pivoting machine members are given in angular units. The propelling linear actuators are controlled by servomechanism control providing position and velocity control. Position measurements for the pivoting members measure linear displacement of the propelling actuator. Position commands for the pivoting members are compensated according to the non-linear relationship between displacement of the propelling actuator and the angular displacement of the pivoting member.

Abstract: Servo spool control for tape web positioning is disclosed wherein the position of the web between two spools may be accurately known and controlled and the tension on the web maintained. To accomplish such control, the motors driving the respective spools are driven by dynamic torque signals in response to change in position commands from a computer controller wherein the dynamic torque signals are correlated to the inertial torque and frictional torque of the spools and their drives.

Abstract: In reaction injection molding facilities of the recirculation type, a closed loop system controls the addition of a gas to a mixture of liquid and gas. The system takes a sample volume of the liquid and forces a plunger into the sample volume. The distance travelled by the plunger between two preset pressures of the sample is measured and compared to a reference distance to get a control signal that is used to operate a valve that controls gas admission to the mixture.

Abstract: A slide valve has a spool valve element that is moved unidirectionally to a sequence of three positions during its operating cycle. The valve structure and unidirectional motion of the spool provide a precompression of the fluid being handled. The valve structure also permits relief of excess downstream pressure. Preferably hydraulic liquid is used to drive, position, and reset the spool valve. The spool valve itself has a hollow body with one groove on its outside surface and a valve body with a port at one end that is always in communication with the hollow portion of the spool valve. The slide valve is especially designed for and preferably used in a liquid reaction molding system to direct a reagent between a source (e.g. reservoir) and a destination (e.g. a mixing head). When applied to such a reaction molding system each slide valve replaces three conventional ball valves and one check valve and yet provides the additional features of precompression and relief of excess pressure.