Patents Represented by Attorney Murray E. Thirft
  • Patent number: 5344121
    Abstract: A winch, for example, for winding in and paying out a cable attached to a person in a hazardous situation, for example underground, comprises a pair of axles mounted on a frame, one of the axles carrying the cable drum for rotation therewith. Two safety brakes are provided, one on each axle, and each including a cam actuated clutch so that rotation of the drum in the pay-out direction is only allowed when the axles are driven in the pay-out direction. A handle for driving the axles includes two hand grasp portions for different mechanical advantage. The handle can be located at two different positions on a drive sprocket on one of the axles or on a second drive sprocket freely rotatable on the first axle for different drive ratios.
    Type: Grant
    Filed: January 4, 1993
    Date of Patent: September 6, 1994
    Inventor: Morris Baziuk
  • Patent number: 5179801
    Abstract: A cattle gate has a base frame adapted to rest on a ground surface. Upright end frames are secured to the base frame at opposite ends and suspend a grid over the center of the base frame using a spring and chain suspension. The gate is a unitary structure that can be transported either using a truck or by attaching a pair of wheels and a hitch for towing purposes.
    Type: Grant
    Filed: July 5, 1991
    Date of Patent: January 19, 1993
    Inventors: Victor E. Babchuk, Gordon R. Brown
  • Patent number: 4979781
    Abstract: A method and apparatus for bench mining employs a rotating wheel excavator with excavator wheel positioned outwardly to one side of a tractor unit for the excavator so that the tractor unit draws the excavation wheel along a bench line or cut line between different layers of the bench mine. The cutting wheel can either be moved to opposite sides of the tractor unit or a second wheel can be positioned at the other side so that the excavator can operate in both directions of movement.
    Type: Grant
    Filed: September 11, 1989
    Date of Patent: December 25, 1990
    Assignee: G.D. Mechanial Design Ltd.
    Inventors: John C. Bothwell, Glen H. Doyle