Robertshaw Controls Company

Alfred A Frankenberg

Douglas R Scott

Earl C Pearson

A bellows valve assembly installed in a fluid pathway includes a valve body, a bellows housing positioned adjacent the valve body, and a valve actuator. The valve body is equipped with an inlet, an outlet, a valve bore positioned between the inlet and the outlet, and a valve seat disposed between the inlet and the outlet. A valve closure element having a sealing surface is positioned in the valve bore and is engageable with the valve seat to restrict fluid flow through the valve bore. The valve closure element also has a valve stem that extends from the valve bore through the bellows housing. The valve stem has a lower portion characterized by a first average diameter and an upper portion characterized by a second average diameter that is at least 25% smaller than the first average diameter. The actuator is engageable with the upper portion of the valve stem to move the sealing surface relative to the valve seat. Further, a pressure-balanced bellows assembly is positioned in the bellows housing and has at least one section secured to the valve stem such that the bellows assembly surrounds a portion of said valve stem. The bellows assembly divides the bellows housing into a first chamber defined inside of the bellows assembly and a second chamber defined outside of the bellows assembly. A first passageway is provided to extend between the first chamber and a location in the fluid pathway downstream of the valve seat so as to communicate the fluid pressure downstream of the valve seat to the first chamber. Further, a second fluid passageway is provided to extend between the second chamber and a location in the fluid pathway upstream of the valve seat so as to communicate the fluid pressure upstream of the valve seat to the second chamber.

Bellows balanced valve

A valve for combining exhaust gas from an engine combustion chamber with engine intake gases. The valve includes a valve body having a gas inlet and a gas outlet connected by a throughpassage. A flow control member supported by the valve body regulates flow through the valve body throughpassage. A magnetic drive is supported for movement with respect to the valve body and coupled to the flow control member to regulate flow in the throughpassage. An electronically actuated field-generating solenoid moves the magnetic drive member to control flow through the valve body. The solenoid and a sensor for monitoring a position of the magnetic drive are supported within a plastic molded housing. The plastic housing also partially encapsulates a pole piece that forms a magnetic circuit in combination with the magnetic drive.

Solenoid activated exhaust gas recirculation valve

A valve for combining exhaust gas from an engine combustion chamber with engine intake gases. The valve includes a valve body having a gas inlet and a gas outlet connected by a throughpassage. A flow control member supported by the valve body regulates flow through the valve body throughpassage. A magnetic drive is supported for movement with respect to the valve body and coupled to the flow control member to regulate flow in the throughpassage. An electronically actuated field-generating solenoid moves the magnetic drive member to control flow through the valve body.

A digital clock construction, a pinion gear therefor and methods of making the same are provided, the clock construction comprising a frame, first and second time indicating drums each being rotatably carried by the frame, and a pinion gear rotatably carried by the frame and having driving gear teeth disposed in meshing relation with an annular internal gear of the second drum whereby rotation of the pinion gear causes rotation of the second drum, the pinion gear having locking teeth extending from certain of the driving teeth thereof, the first drum having an annular internal locking surface that is adapted to slide against a pair of locking teeth to hold the pinion gear from rotation thereof while the first drum is being rotated through certain timed increments of movement thereof, the first drum having a pair of kicker teeth for meshing with the driving teeth of the pinion gear to rotate the pinion gear when the first drum is being rotated through a particular one of the timed increments of movement thereof, the first drum having a relief in the locking surface thereof that is located adjacent the kicker teeth thereof for receiving one of the locking teeth therein as the pinion gear is being rotated by the kicker teeth, the locking teeth each having a part thereof that is adapted to cooperate with the relief to prevent any substantial rotation of the pinion gear in one direction thereof after the first drum has completed the particular timed increment of movement thereof and that respective locking tooth is in alignment with the relief so as to be out of engagement with the locking surface.

Digital clock construction, pinion gear therefor and methods of making

An exhaust system for an internal combustion engine which burns a hydrocarbon fuel mixture and which produces a carbonaceous particle carrying exhaust gas stream that passes through a filter of the system that retains at least part of the particles therein, the system having a burn-off unit for periodically burning the retained particles in the filter to tend to periodically clean the filter of the retained particles thereof. The burn-off unit is adapted to raise the temperature of the exhaust gas stream intermediate the engine and the filter to raise the temperature of the filter to particle burning temperature thereof, the burn-off unit injecting and burning a certain amount of the hydrocarbon fuel mixture in the exhaust gas stream intermediate the engine and the filter to raise the temperature of the exhaust gas stream intermediate the engine and the filter. The fuel mixture is injected into the exhaust gas stream by an aspirating unit of the burn-off unit, and the temperature of the exhaust gas stream is raised by an electrical heater and a catalyst bed in which the injected fuel mixture is to burn.

Exhaust system for an internal combustion engine, burn-off unit and

A thermostat construction having a valve unit for directing a pneumatic signal to a pneumatically operated control device in relation to the force differential between the temperature sensed by the temperature sensing unit thereof and the temperature setting of a temperature setting unit thereof, the construction having a lever pivotally mounted thereto and being operatively interconnected to the valve unit at a first portion of the lever and to the temperature setting unit and the temperature sensing unit at a second portion of the lever by a post-like member. The post-like member has a pivot section thereof pivotally interconnected to the lever at the second portion thereof to operatively interconnect the temperature setting unit and the temperature sensing unit to the second portion of the lever to compensate for any misalignment between the operating parts. The temperature setting unit comprises a bimetal member and the post-like member has a link pivotally mounted thereto and provided with a pin that bears against the bimetal member to pivotally interconnect the bimetal member to the link and, thus, to the post-like member.

Pneumatically operated thermostat construction and method of making the

A method of making a pneumatically operated actuator having a pneumatically operated movable wall interconnected by a feedback tension spring to a pilot valve positioner that is adapted to pneumatically operate the movable wall of the actuator in relation to a pneumatic signal directed to the positioner, the method including the steps of loosely projecting one end of the spring through an opening in the wall after the other end of the spring has been interconnected to the pilot valve positioner and pulling on the one end of the spring while directing a predetermined pneumatic signal to the positioner so that the wall will assume a position thereof relative to the one end of the spring and the actuator that corresponds to the predetermined pneumatic signal whereby the one end of the spring can be secured to the wall while the wall is in that position thereof and the spring is in the pulled condition thereof that caused the wall to move to such position.

Pneumatically operated actuator and method of making the same

A thermostat construction for producing a pneumatic signal in relation to sensed temperature and having a housing provided with a pneumatically operated set point adjustment diaphragm operatively interconnected to a temperature sensor and a pneumatically operated feedback diaphragm to control a valve unit for producing the pneumatic signal in an output chamber of the housing that is defined in part by the feedback diaphragm, a balancing diaphragm being carried by the housing and also defining in part the output chamber thereof.

Growing community of inventors

Knoxville, TN, United States of America

Alfred A Frankenberg