Patents Assigned to Lift-Tech International, Inc.
  • Patent number: 5140247
    Abstract: A system for controlling the start-up sequence of an electric motor includes a contactor relay for supplying polyphase operating voltage to the motor. A plurality of output circuits are respectively coupled between the motor and the relay contacts. Each output circuit is responsive to an output control signal applied to an input thereof for applying the operating voltage to the motor. An acceleration ramp generator is responsive to a motor control circuit which energizes the relay for providing a first signal which gradually rises upon the initial activation thereof. A phase control ramp generator is responsive to the application of the polyphase operating voltage to provide a second signal which decreases from a given level upon the initial application of the operating voltage. A plurality of comparators are provided each comparator having first and second inputs respectively coupled to receive each phase control ramp generator signal and the acceleration ramp generator signal.
    Type: Grant
    Filed: February 5, 1988
    Date of Patent: August 18, 1992
    Assignee: Lift-Tech International, Inc.
    Inventor: Stephen P. Verbos
  • Patent number: 4841215
    Abstract: A D.C. solenoid control circuit for use in mechanisms driven by an A.C. motor. A rectifier converts A.C. current to D.C. current and provides an A.C. current flow path and a D.C. current flow path. Only the motor is connected in the A.C. current flow path to an output electrical power source. The D.C. solenoid is connected through the rectifier in the D.C. current flow path. The D.C. solenoid winding drives an actuator within the solenoid the activate the separate mechanism. In-rush current drawn by the motor upon start-up is converted to a high current level by the rectifier and input to the winding of the solenoid causing its immediate energization and, upon de-activation, its fast release.
    Type: Grant
    Filed: June 22, 1987
    Date of Patent: June 20, 1989
    Assignee: Lift Tech International Inc.
    Inventor: Stephen P. Verbos
  • Patent number: 4828077
    Abstract: An inner pressure pad is positioned on support members adjacent to the disk and generally parallel to the disk. An outer pressure pad is positioned on the support members with the disk interposed in between the inner pressure pad and the outer pressure pad, and the outer pressure pad is generally parallel to the disk. Springs are inserted on the support members and interposed in between the inner pressure pad and the outer pressure pad to urge the outer pressure pad away from the disk. A lever is pivotally mounted on the support members at a distance away from the outer pressure pad, and normally extends generally parallel to the outer pressure pad. Adjusting means are secured to the lever with one end extending to normally contact the outer pressure pad. A frame member is secured to the support members to partially enclose the lever and the disk. The frame member has a fulcrum formed thereon protruding from the frame member to contact the lever on the side opposite from the disk.
    Type: Grant
    Filed: February 22, 1988
    Date of Patent: May 9, 1989
    Assignee: Lift-Tech International, Inc.
    Inventor: Howard C. Stevens Jr.
  • Patent number: 4749067
    Abstract: An inner pressure pad is positioned on support members adjacent to the disk and generally parallel to the disk. An outer pressure pad is positioned on the support members with the disk interposed in between the inner pressure pad and the outer pressure pad, and the outer pressure pad is generally parallel to the disk. Springs are inserted on the support members and interposed in between the inner pressure pad and the outer pressure pad to urge the outer pressure pad away from the disk. A lever is pivotally mounted on the support members at a distance away from the outer pressure pad, and normally extends generally parallel to the outer pressure pad. Adjusting means are secured to the lever with one end extending to normally contact the outer pressure pad. A frame member is secured to the support members to partially enclose the lever and the disk. The frame member has a fulcrum formed thereon protruding from the frame member to contact the lever on the side opposite from the disk.
    Type: Grant
    Filed: November 6, 1986
    Date of Patent: June 7, 1988
    Assignee: Lift-Tech International, Inc.
    Inventor: Howard C. Stevens, Jr.