Abstract: A closed loop control system for a pneumatic actuator using position and pressure feedback signals. The feedback signals are supplied to a microprocessor which successively generates a desired acceleration, a desired actuator force, a desired gas pressure, and a gas mass flow rate command for a gas flow controlling valve. The use of the gas flow rate as a control variable decouples pneumatic ronlinearities from the control loop. Nonlinear viscous friction, coulomb friction and load effects are decoupled from the control loop prior to the calculation of the desired pressure. An improved trajectory is achieved by employing a plurality of trajectory phases, including a velocity control phase.
August 2, 1991
Date of Patent:
June 13, 1995
Mosier Industries, Inc.
David J. Bolt, Richard J. Bethke, David J. Rediess
Abstract: An impact damping element is provided including an annular bumper portion and a seal portion surrounding the bumper portion for engaging an inner wall of a cylinder in sealing contact. The impact damping element is adapted to absorb the impact between a piston and the end of a cylinder wall. In one embodiment of the invention, a primary and a secondary bumper are provided wherein the primary bumper has a greater height than the secondary bumper such that the primary bumper absorbs an initial impact between the piston and the cylinder wall and the secondary bumper absorbs the remaining force to prevent direct contact between the piston and the cylinder wall.
Abstract: An impact dampening ring is disclosed having a primary bumper and a secondary bumper for dampening the engagement of a piston against an end of a power cylinder. The primary bumper has a curved or arcuate surface for initial engagement with the end of the cylinder and the secondary bumper has a flat surface for secondary engagement with the end of the cylinder. The engagement of the primary and secondary bumpers dampens the impact and prevents the piston from directly engaging the end of the power cylinder. A mounting flange on the impact dampening rings provides a means for mounting the impact dampening ring onto a mounting surface of the piston. A seal along the outer perimeter of the impact dampening ring provides a fluid tight seal for the piston inside of the power cylinder.
Abstract: A pressure control valve and transducer package for use in combination with a pneumatic actuator which incorporates a double acting pneumatic cylinder includes, in a single multi-component unit, a valve assembly constructed for direct coupling into the pneumatic pressure loop for operating the actuator, and a second component which comprises a fixture housing one or more continuously operating sensors for measuring the pressures supplied to the opposite ends of the cylinder in the actuator and transmitting appropriate signals conveying that information to a microprocessor which in turn regulates the supply flow rate of pressure gas to the cylinder through a closed loop feedback system.
Abstract: This invention relates to power valve assemblies and systems thereof and more particularly to their controls. It features a body having flow passages through which control fluid is directed to operate the interrelated valve. Said body is constructed to provide therein a plurality of openings or cavities each of which intersect one or more of said flow passages. Per the present invention, a plurality of unique independent adapters or control units are provided for application to said openings or cavities. Said adapters and/or control units are so designed that each thereof has different form and utility, may be selectively applied to said openings or cavities and easily and quickly interchanged or shifted from one thereof to another by virtue of which to influence the delivery and mode of application of control fluid and thereby the means and/or mode of control of the operation of the valve to which they relate.
Abstract: Control apparatus includes means defining a housing having a hollow and a piston device mounted for reciprocating movement in said hollow under the influence of pressure fluid applied alternately to each of opposite portions of its surface, characterized by means for transmitting a signal of a predetermined travel of said piston in one direction, said signal transmitting means being constructed and arranged to utilize applied pressure fluid in its signalling function.