Patents Represented by Law Firm Candor, Candor & Tassone
  • Patent number: 5002038
    Abstract: A burner construction and method of making the same are provided, the burner construction comprising a burner body having a chamber therein and having opposed ends one of which is open to the chamber and the other of which has structure for interconnecting a source of fuel to the chamber, and a removable cap closing the one end of the body, the burner construction having ports interconnecting the chamber to the exterior of the burner construction and through which the fuel can issue to burn externally to the burner construction, the burner construction comprising a removable venturi section disposed in the chamber and being removable therefrom through the open end of the body when the cap has been removed therefrom.
    Type: Grant
    Filed: December 12, 1989
    Date of Patent: March 26, 1991
    Assignee: Robert Shaw Controls Company
    Inventor: Fred Riehl
  • Patent number: 4996886
    Abstract: A differential pressure transmitter, a pneumatically operated square root extracting device therefor and methods of making the same are provided, the transmitter having a rod operatively interconnecting a movable wall with a cam roller to cause the roller to roll on a flat surface as the value of the pressure in an output chamber defined by the movable wall changes, the rod and the movable wall respectively having universal joint units snap-fitted together to provide for universal movement therebetween while movement of the wall causes the roller to roll.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: March 5, 1991
    Assignee: Robertshaw Controls Company
    Inventor: George T. Hardin
  • Patent number: 4996885
    Abstract: A differential pressure transmitter, a pneumatically operated square root extracting device therefor and methods of making the same are provided, the transmitter comprising a unit for producing an output pneumatic signal from a pneumatic source in relation to the air velocity pressure of air flowing in a passage, a unit that senses the difference between the total pressure and the static pressure of the air flowing in the passage, and a unit for extracting the square root of the air velocity pressure of the air from the pneumatic output signal as the pneumatic output signal is being produced so that the pneumatic output signal is substantially linear with respect to the air velocity of the air flow in the passage whereby the transmitter comprises a linear air velocity transmitter, the unit for extracting the square root comprising a cam having a cam face that defines at least part of the involute of a circle.
    Type: Grant
    Filed: February 27, 1990
    Date of Patent: March 5, 1991
    Assignee: Robertshaw Controls Company
    Inventor: Clarence M. Asbill, III
  • Patent number: 4997161
    Abstract: A fuel control system, throttle valve unit therefor and methods of making the same are provided, the system comprising a burner, a source of fuel for the burner, and a throttle valve unit for interconnecting the source to the burner, the throttle valve unit having a movable valve member and a valve seat controlled by the valve member, the throttle associated with the valve member to control the position of the valve member relative to the valve seat so as to control the flame height at the burner, the electrically operated unit comprising a fixed magnet unit and a movable magnet unit each of which is adapted to provide a magnetic field that will react with the other magnetic field, one of the magnet units having an electrical conductor that is adapted to vary the force of its magnetic field in relation to the magnitude of an electrical current passing therethrough whereby the valve member is adapted to be positioned relative to the valve seat in relation to the effect created between the magnetic fields.
    Type: Grant
    Filed: February 22, 1990
    Date of Patent: March 5, 1991
    Assignee: Robertshaw Controls Company
    Inventors: Donald W. Hutchison, Steven A. Kimmel, Raymond J. Bonkovich, James P. Chew, David J. Rath
  • Patent number: 4997361
    Abstract: A low cost hot surface ignition system particularly adapted for use in gas furnaces and the like, the system including low voltage control and timing circuitry effective to control a gas valve and high voltage ignition circuitry incorporating a hot surface silicon carbide igniter disposed in the path of incoming gas and in the heat of the flame when ignition is achieved to effect flame rectification resulting in flame sensing. The system also provides fail-safe operation or safety shutdown of the associated furnace if ignition is not achieved or in the event of a failure of a component of the system.
    Type: Grant
    Filed: June 13, 1989
    Date of Patent: March 5, 1991
    Assignee: Robertshaw Controls Company
    Inventor: Frederick J. Geary
  • Patent number: 4994653
    Abstract: A temperature regulating control unit and method of making the same are provided, the unit comprising a RTD temperature sensor, a unit for applying electrical signals to the sensor, and a microcomputer for receiving digital signals from the sensor in relation to the temperature being sensed by the sensor, the unit for applying electrical signals to the sensor applying a varying voltage to the sensor.
    Type: Grant
    Filed: November 30, 1989
    Date of Patent: February 19, 1991
    Assignee: Robertshaw Controls Company
    Inventors: Brian J. Kadwell, Daniel L. Fowler, Gregory F. Gawron
  • Patent number: 4993144
    Abstract: A cyclable electrical switch construction, a system utilizing the switch construction and methods of making the same are provided, the cyclable electrical switch construction comprising a housing having a cyclable electrical switch therein and a rotatable actuator shaft that extends from the housing for setting the duty cycle of the switch in relation to the rotational position of the shaft in either rotational direction thereof from an "off" position thereof, and an electrical switch unit being carried on the housing and having structure operatively interconnected with the shaft so that the switch unit is actuated from one condition thereof to another condition thereof only when the shaft is rotated from the "off" position thereof in one rotational direction thereof.
    Type: Grant
    Filed: September 19, 1989
    Date of Patent: February 19, 1991
    Assignee: Robertshaw Controls Company
    Inventors: David T. Llewellyn, William J. Lichtenberger
  • Patent number: 4982704
    Abstract: A vehicle cooling system subassembly, parts therefor and methods of making the same are provided, the subassembly comprising an outlet housing having an opening therein, and a vehicle type thermostat disposed in the opening of the outlet housing and having a housing provided with a valve seat that is controlled by a movable valve member which is interconnected to a temperature responsive device that is carried by the thermostat housing, the outlet housing having a positioning device thereon, the thermostat housing having a positioning device thereon engaging the positioning device of the outlet housing to rotationally orient the thermostat in the opening of the outlet housing in a desired rotational position thereof, the outlet housing having a slot therein, the thermostat housing having a tab extending outwardly therefrom and wedgingly disposed in the slot to hold the thermostat in the opening of the outlet housing in the desired rotational position thereof.
    Type: Grant
    Filed: January 12, 1990
    Date of Patent: January 8, 1991
    Assignee: Robertshaw Controls Company
    Inventor: Boyd P. Sliger
  • Patent number: 4976605
    Abstract: A hot surface ignition system for a gas furnace or the like, control device therefor and methods of making the same are provided, the system comprising a burner, a settable thermostat, an electrically operable gas valve, a control unit, and an electrically operable hot surface igniter disposed so as to be in the path of gas issuing from the burner that is adapted to be fed the gas from a source thereof through the gas valve when the control unit has been activated by the thermostat to operate the igniter and the gas valve in a certain sequence, the control unit having a lockout unit for deactivating the system should ignition of the gas issuing from the burner not take place by the end of the certain sequence, the control unit having a resetting unit for causing the control unit to be reactivated to be adapted to repeat the certain sequence of the system when the resetting unit is activated, the control unit being adapted to select the certain sequence to have one or more attempts of the control unit to ignit
    Type: Grant
    Filed: May 24, 1989
    Date of Patent: December 11, 1990
    Assignee: Robertshaw Controls Company
    Inventor: Frederick J. Geary
  • Patent number: 4975166
    Abstract: An apparatus and method for removing liquid from liquid bearing material are provided, the apparatus comprising a pair of electrodes having portions thereof disposed adjacent each other and defining an inlet to the adjacent portions and an outlet from the adjacent portions, structure for feeding the liquid bearing material into the inlet, structure for moving the liquid bearing material from the inlet to the outlet so that sections of the material serially move from the inlet to the outlet while being disposed between the adjacent portions, and a unit for creating a voltage arrangement between the pair of electrodes so as to create an electrostatic field arrangement between the adjacent portions of the pair of electrodes for acting through the material that is disposed therebetween to remove liquid from that material, the unit providing different voltages between different parts of the pair of electrodes so that different intensities of the electrostatic field arrangement serially act through each section of
    Type: Grant
    Filed: December 21, 1989
    Date of Patent: December 4, 1990
    Inventor: James T. Candor
  • Patent number: 4975043
    Abstract: A control device for supplying fuel to a burner means, a system therefor and methods of making the same are provided, the device comprising a housing having an inlet for being interconnected to a source of fuel and having an outlet for being interconnected to the burner, first and second control valves carried by the housing and being in series to connect the inlet to the outlet only when both of the control valves are in an open condition thereof, each control valve comprising a movable valve member resiliently biased closed and an independent electromagnetic valve member latching unit energizable to hold its respective valve member open and deenergizable to allow its respective valve member to close, each control valve having a movable member to open its respective valve member to a latching position so as to be held open by its respective latching unit when its respective latching unit is energized, and a single manually movable actuator carried by the housing and having structure operatively interconnecti
    Type: Grant
    Filed: August 11, 1989
    Date of Patent: December 4, 1990
    Assignee: Robertshaw Controls Company
    Inventors: Jay R. Katchka, George A. Yeaman, Richard W. McKinney
  • Patent number: 4971549
    Abstract: A control unit for a gas furnace that has an electrically operable pilot gas valve and an electrically operable main gas valve and a method of making the control unit are provided, the control unit comprising an electrical circuit having a gas valve section that comprises a silicon controlled rectifier and a first capacitor and a second capacitor so electrically interconnected together that the capacitors are adapted to be charged on each half wave cycle of a certain polarity of an alternative current source that is imposed on the circuit and that second capacitor is adapted to discharge through a relay coil that controls the gas valve to energize that relay coil only when the silicon controlled rectifier conducts, the silicon controlled rectifier being adapted to conduct only when the first capacitor is discharged, another section of the electrical circuit being adapted to discharge the first capacitor only on each half wave cycle of the other polarity of the alternative current source.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: November 20, 1990
    Assignee: Robertshaw Controls Company
    Inventor: Frederick J. Geary
  • Patent number: 4971095
    Abstract: A fuel control valve construction, parts therefor and methods of making the same are provided, the construction comprising a housing having an inlet adapted to be interconnected to a fuel source and an outlet adapted to be interconnected to a main burner, the housing having a pilot outlet adapted to be interconnected to a pilot burner for the main burner, the housing having a pilot valve seat and a main valve seat for interconnecting the inlet respectively with the pilot outlet and the main outlet, the housing having a movable pilot valve member for opening and closing the pilot valve seat and a movable main valve member for opening and closing the main valve seat, the housing having a movable lever carrying the pilot valve member and the main valve member and having a manually operable actuator for controlling the operating positions of the lever.
    Type: Grant
    Filed: February 20, 1990
    Date of Patent: November 20, 1990
    Assignee: Robertshaw Controls Company
    Inventors: Samuel T. Kelly, Jay R. Katchka
  • Patent number: 4969628
    Abstract: A valve construction and method of making the same are provided, the valve construction comprising a housing having an inlet and an outlet and a valve seat adapted to be interconnected to the inlet and the outlet, a movable valve member carried by the housing and being operatively associated with the valve seat to control fluid flow therethrough from the inlet to the outlet, and a stepper motor carried by the housing and being operatively interconnected to the movable valve member to move the movable valve member relative to the valve seat to control the fluid flow through the valve seat, the movable valve member comprising a flexible part for sealing closed the valve seat when the stepper motor moves the flexible part against the valve seat and a throttlling part extending beyond the flexible part and into the valve seat to throttle the fluid flow therebetween when the stepper motor has moved the flexible part away from the valve seat and the throttling part has a portion thereof disposed in the valve seat.
    Type: Grant
    Filed: November 20, 1989
    Date of Patent: November 13, 1990
    Assignee: Robertshaw Controls Company
    Inventors: Richard B. Reich, George W. Feild
  • Patent number: 4961530
    Abstract: An engine cooling system, structure therefor and methods of making the same are provided, the system comprising a housing having an inlet and an outlet, and a thermostat construction disposed in the housing between the inlet and the outlet for controlling the degree of fluid flow therebetween, the thermostat construction comprising a valve seat unit, a valve closure unit for opening and closing the valve seat unit, a spring operatively interconnected to the valve closure unit to tend to close the same against the valve seat unit, and a temperature responsive device comprising a piston member and a cylinder member that are adapted to provide relative movement therebetween when the device senses certain temperatures, one of the members being interconnected to the valve closure unit to move the same in unison therewith in opposition to the force of the spring when the other of the members is fixed from movement relative to the housing, and a movable stop carried by the housing and having a plurality of different
    Type: Grant
    Filed: October 10, 1989
    Date of Patent: October 9, 1990
    Assignee: Robert Shaw Controls Company
    Inventor: Joseph P. Wagner
  • Patent number: 4958801
    Abstract: A valve construction and method of making the same are provided, the valve construction comprising a housing provided with a chamber therein and with an inlet leading to the chamber and outlet leading from the chamber, a valve seat carried by the housing and leading to the outlet, a movable bimetallic lever carried by the housing and having an operating bimetallic part, a heater wire disposed in coiled relation about the operating part to heat the same when an electrical current flows through the heater wire, and a valve member carried by the bimetallic lever for opening and closing the valve seat under the control of the operating part of the bimetallic lever, the operating part of the bimetallic lever having a fastening unit operatively interconnected to the heater wire to tend to hold the heater wire in the coiled relation on the operating part of the bimetallic lever, the heater wire comprising a length of the wire doubled upon itself to define a looped end and pair of free ends adjacent each other with t
    Type: Grant
    Filed: September 19, 1989
    Date of Patent: September 25, 1990
    Assignee: Robertshaw Controls Company
    Inventor: Harvey J. Shopsky
  • Patent number: 4951810
    Abstract: A control device, switch unit therefor and methods of making the same are provided, the electrical switch unit comprising a switch having a movable actuator, a lever pivotally carried by the switch unit and having one end adapted to be operatively interconnected to a movable part of a control device so as to be pivoted by the movement thereof, the lever being operatively interconnected to the actuator to operate the switch between the different conditions thereof in relation to the pivoted position of the lever, and a pair of mounting plates respectively having holding structure that hold the switch between the plates and respectively having pivot structure that pivotally mount the lever between the plates whereby the plates, the switch and the lever form a self-supporting switch unit.
    Type: Grant
    Filed: February 26, 1990
    Date of Patent: August 28, 1990
    Assignee: RobertShaw Control Company
    Inventor: Charles J. Everett
  • Patent number: 4951880
    Abstract: A burner construction and a method of and an apparatus for making the same are provided, the burner construction comprising a wall structure having an exterior surface and having an interior surface that defines a chamber in the burner construction for receiving fuel from a fuel source, the wall structure having a plurality of elongated ports formed through the surfaces thereof and thereby communicating with the chamber, the ports being disposed in spaced apart substantially parallel relation with each port being defined between a pair of adjacent edges of the wall structure that are disposed in spaced apart substantially parallel relation whereby fuel is adapted to flow from the chamber out through the ports between the adjacent edges thereof to burn adjacent the exterior surface of the wall structure, the edges each being extruded into the chamber beyond the interior surface of the wall structure.
    Type: Grant
    Filed: December 13, 1989
    Date of Patent: August 28, 1990
    Assignee: RobertShaw Controls Company
    Inventor: Fred Riehl
  • Patent number: 4947891
    Abstract: A fuel control device, system using the device and method of making the same are provided, the device comprising a housing having a passage therethrough for interconnecting a fuel source with a main burner, a throttle valve unit disposed in the passage for throttling fuel flow through the passage to the burner, and a selector operatively interconnected to the throttle valve unit to operate the same, the throttle valve unit comprising a pair of members one of which is substantially stationary and the other of which is rotable relative to the one member, the one member having a face and having an aperture interrupting the face thereof and passing therethrough, the other member having a face disposed in sliding engagement with the face of the one member for controlling the efffective opening of the aperture for fuel flow therethrough, the selector being operatively interconnected to the other member to rotate the same relative to the one member and thereby control the flow of fuel through the passage, the other
    Type: Grant
    Filed: July 12, 1989
    Date of Patent: August 14, 1990
    Assignee: Robertshaw Controls Company
    Inventor: Francis S. Genbauffe
  • Patent number: 4948950
    Abstract: A heating system, a deep fat fryer, control devices therefor and methods of making the same are provided, the control device comprising a temperature sensing unit for sensing the actual temperature of the output heating effect of a heat producing unit, and a setpoint unit for selecting a desired setpoint temperature that the heat producing unit is to provide with the output heating effect thereof, the control device being so constructed and arranged that the same is adapted to tend to cause the heat producing unit to provide the desired setpoint temperature with the output heating effect thereof, the control device being so constructed and arranged that the same is adapted to turn off the heat producing unit if the actual rate of change of the temperature of the output heating effect thereof is greater than a target rate of change thereof when the actual temperature of the output heating effect at that time is below the desired setpoint temperature and to turn on the heat producing unit if the actual rate of
    Type: Grant
    Filed: April 25, 1989
    Date of Patent: August 14, 1990
    Assignee: Robertshaw Controls Company
    Inventor: Richard H. Rae