Patents Represented by Law Firm Candor, Candor and Tassone
  • 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: 4910052
    Abstract: A sheet of mulch material and method of making the same are provided, the sheet of mulch material comprising a sheet of polymeric material having openings passing therethrough and opposed sides one of which is to face the ground on which the sheet of mulch material is to be disposed, and a sheet of fabric material being coextensive with and being secured to the one side of the sheet of polymeric material and overlapping the openings thereof to tend to prevent plant growth through the openings.
    Type: Grant
    Filed: August 12, 1988
    Date of Patent: March 20, 1990
    Assignee: Dalen Products Inc.
    Inventor: Edward N. Caldwell