Patents Assigned to Dewhurst & Partner Limited
  • Patent number: 4020926
    Abstract: A brake apparatus having components formed from sheet metal pressings or stampings which brake apparatus includes a pair of brake arms each pivotally connected with a base on opposite sides of a brake drum. The brake arms are spring-biased together to urge brake shoes thereon into braking engagement with opposite sides of a brake drum, respectively. A normally de-energized brake release mechanism is provided for pivoting the brake arms apart against the force of the spring biasing device, thereby releasing the brake shoes from engagement with the drum. The base and the brake arms are constructed as assemblies of sheet metal pressings, and the electromagnetic parts of the brake release mechanism include lamination stacks which are sandwiched between side plates of one of the arms.
    Type: Grant
    Filed: February 10, 1976
    Date of Patent: May 3, 1977
    Assignee: Dewhurst & Partner Limited
    Inventors: John Reginald Slatter, James Albert Jackson, John Gedny Brooks, Albert John Clark Ward, Alan Dewhurst
  • Patent number: 3945470
    Abstract: Control apparatus having particular application to the control of the deceleration of an elevator or lift car in approach of a stop position, the apparatus including a sense coil mounted on the lift car and a magnetic member mounted on the lift shaft to vary the flux through the sensing coil in a predetermined manner relative to the distance to go to the stop position, the deceleration being controlled in accordance with the voltage induced by the flux in the sense coil. A magnetically operated switch is also provided on the lift car to respond to the magnitude of the flux to provide a stop signal defining the stop position.
    Type: Grant
    Filed: March 11, 1974
    Date of Patent: March 23, 1976
    Assignee: Dewhurst & Partner Limited
    Inventor: George Eric Minns