Abstract: A method for locating a mobile unit without synchronizing base-stations is provided. A triangulation scheme where distances between a plurality of base-stations and a mobile unit (herein termed mobile) are calculated by measuring at least three round-trip-delay-values wherein each round-trip-delay-value corresponds to transmission of a downlink signal from each base-station to the mobile unit and transmission of an uplink signal, in response to the downlink signal, from the mobile unit to each base-station is described. It is a low-cost solution without requiring the participating base-stations to be accurately synchronized in time and with the added advantages of utilizing a known downlink signal and a known uplink signal in determining the position of the mobile.

Abstract: A vacuum control apparatus for generating and controlling the source of vacuum produced from a source of pressurized air in communication with at least one vacuum responsive device wherein the vacuum control apparatus maintains the operating conditions of the system during the loss and resumption of power. The vacuum control apparatus provides at least one venturi for creating a vacuum through a flow of pressurized air. A first valve train selectively provides a flow of pressurized air from a pressurized air source to the vacuum creating means. A second valve train communicates with the pressurized air source to selectively provide a flow of pressurized air to the vacuum responsive device. A last function valve communicates with the first and second valve trains and a pressurized air source to maintain the operating condition of the vacuum control apparatus during the loss and resumption of power to the first and second valve trains.

Abstract: A method for generating and controlling the source of vacuum produced from a source of pressurized air in communication with at least one vacuum responsive device wherein the present invention maintains the operating conditions of the system during the loss and resumption of power. The present invention provides at least one venturi for creating a vacuum through a flow of pressurized air. The present invention selectively provides a flow of pressurized air from a pressurized air source to the vacuum creating means and selectively provides a flow of pressurized air to the vacuum responsive device. A last function valve communicates with the selective providing of pressurized air to maintain the operating condition of the vacuum responsive device during the loss and resumption of power.

Abstract: A sensor detects the absolute angular position of a rotatable clamp arm between full opened and full closed positions. The sensor is coupled to a clamp arm pivot shaft to provide output signals corresponding to the absolute position of the clamp arm. One or more programmable angular position set points are setable at angular positions in advance of the full open and full closed positions of the clamp arm. Outputs are generated when the clamp arm reaches and/or exceeds each set point.

Abstract: A sensor detects the absolute angular position of a rotatable clamp arm between full opened and full closed positions. The sensor is coupled to a clamp arm pivot shaft to provide output signals corresponding to the absolute position of the clamp arm. One or more programmable angular position set points are setable at angular positions in advance of the full open and full closed positions of the clamp arm. Outputs are generated when the clamp arm reaches and/or exceeds each set point.

Abstract: A shiftable valve spool has a plurality of distinct targets carried thereon. The targets are preferably axially spaced and located at one end of the valve spool. A detector mounted in the valve detects each target as each target enters a detection field of the detector. The detector generates a distinct output indicative of one target positioned within the detection field of the detector. A control determines, in response to the output from the detector, the exact valve spool position.

Abstract: A vacuum cup control apparatus for applying and releasing vacuum in a vacuum cup includes a venturi passage for inducing a vacuum within the vacuum cup upon the flow of pressurized air therethrough. Another air flow passage extends through the housing for injecting a flow of air under pressure to the vacuum cup to relieve the vacuum therein. A sensor senses the vacuum level attained in the vacuum cup. A feedback signal is sent by the control apparatus to the external controller as an indication that a predetermined, selectable vacuum level has been achieved. The control apparatus is responsive to the sensor and signals from an external controller for applying vacuum to the vacuum cup until a predetermined vacuum level is attained in the vacuum cup.

Abstract: A vacuum cup control apparatus for applying and releasing vacuum in a vacuum cup engaging a workpiece includes a housing having a venturi passage for inducing a vacuum within the vacuum cup upon the flow of air through the venturi passage. A one-way check valve in the passage seals the vacuum in the vacuum cup upon cessation of air flow through the venturi passage. Another air flow passage extends through the housing to a control port on the housing for injecting a flow of air under pressure to the vacuum cup to relieve the vacuum therein. A sensor mounted in the housing senses the vacuum level attained in the vacuum cup. A feedback signal is sent by the control apparatus to the external controller as an indication that a predetermined vacuum level has been achieved. The control apparatus is responsive to the sensor and signals from an external controller for applying vacuum to the vacuum cup until a predetermined vacuum level is attained in the vacuum cup.