Patents by Inventor Stafford T. Screen

Stafford T. Screen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5214823
    Abstract: To prevent "shimmying", due to uncontrolled swivelling of a castor during non-engagement of its wheel or wheels with the ground, frictional resistance to swivelling is provided. An upper or lower cap or cover for the bearing between the castor body and its mounting head can thus be non-rotatably engaged with the mounting head and frictionally engaged with the body. Additionally, or instead, a spring washer around the mounting head in an aperture in the body containing the bearing can provide this friction.
    Type: Grant
    Filed: January 29, 1991
    Date of Patent: June 1, 1993
    Inventor: Stafford T. Screen
  • Patent number: 5139116
    Abstract: A caster has two wheels with tires non-rotatably secured to a wheel center and shaped with an internal cylindrical drum surface. A brake member pivoted on the caster body has two side walls with out-turned edge portions engageable with respective drum surfaces. The engagement may be at an upper position, or opposite the ground-engaging portion of the wheels.
    Type: Grant
    Filed: February 4, 1991
    Date of Patent: August 18, 1992
    Inventor: Stafford T. Screen
  • Patent number: 4941552
    Abstract: A castor has a two-armed integrally formed spring metal brake member which is pivoted on the castor body for selective movement between a braking position, in which a detent portion on one arm brakingly engages teeth on the castor wheel, to prevent wheel rotation, and a detent portion on the other arm engages teeth on a mounting member on which the body swivels, to prevent swivelling, and a release position in which the detent portions are spaced from the teeth.
    Type: Grant
    Filed: October 7, 1988
    Date of Patent: July 17, 1990
    Assignee: Colson Castors (Europe) Limited
    Inventor: Stafford T. Screen
  • Patent number: 4747180
    Abstract: A castor has a brake rod (20;120;220) extending through a hollow stem (10) on which a body (4) carrying a pair of castor wheels (2) is rotatably mounted. The brake rod is moveable substantially vertically between an inoperative position and a braking position in which its lower end engages the surface on which the wheel (2) rest. Opposition to braking movement can be provided by a return spring (39;222) or by a spring arm (122). Movement of the brake rod can be effected by a cam (140) acting on the spring arm (122) or by a cam (40;240) acting on a lever (35;230) engaging the upper end of the brake rod. The brake rod (10) can be arranged to have an intermediate position in which rotation of the castor body (4) is prevented.
    Type: Grant
    Filed: June 16, 1986
    Date of Patent: May 31, 1988
    Assignee: Colson Castors (U.K.)
    Inventor: Stafford T. Screen
  • Patent number: 4706329
    Abstract: A castor comprises a moulded plastics body (1) having a socket for a swivel pin and a center wall (6) with an aperture of which the edge is formed as the outer ball track (9) of a ball bearing. Two moulded plastics wheels (2) have hollow hub portions (11) extending towards the center wall and shaped to co-operate to provide the inner ball track (17) of the ball bearing.
    Type: Grant
    Filed: September 6, 1985
    Date of Patent: November 17, 1987
    Assignee: Colson Castors (U.K.)
    Inventor: Stafford T. Screen
  • Patent number: 4677706
    Abstract: A single or twin wheel castor has a body (4,14; 90) journalling the wheel (92) or wheels (2) about a horizontal axis, with the body capable of swivelling on a mounting member (16) about a vertical axis spaced from the wheel axis. An operating member (25) is movable axially but non-rotatably by a cam (30) along the vertical axis between a lower position in which the body is held to the operating member and thus to the mounting member in a predetermined angular orientation, the whole being free to turn, an intermediate position in which the wheels are free to turn and the body is free to swivel and an upper position in which a wheel braking force is applied frictionally or mechanically by a brake lever (44, 105), the engagement of the operating member with the brake lever also holding the body in its angular position when the brake was applied.
    Type: Grant
    Filed: June 19, 1985
    Date of Patent: July 7, 1987
    Assignee: Colson Castors (Europe) Limited
    Inventor: Stafford T. Screen
  • Patent number: 4455707
    Abstract: A castor body comprises integral upper and lower parts (15,21) which can undergo limited relative vertical movement by flexing of arms (25) and (26) of the body. An axle (11) for wheels of the castor is carried in the lower body part and the upper body part has braking elements (27,28) with which the wheels engage when the upper body part is moved upwardly by a spring (24) acting between the body parts.
    Type: Grant
    Filed: September 21, 1981
    Date of Patent: June 26, 1984
    Assignee: British Castors Limited
    Inventor: Stafford T. Screen
  • Patent number: D272416
    Type: Grant
    Filed: December 15, 1980
    Date of Patent: January 31, 1984
    Assignee: British Castors Limited
    Inventor: Stafford T. Screen
  • Patent number: D288286
    Type: Grant
    Filed: September 13, 1984
    Date of Patent: February 17, 1987
    Assignee: Colson Castors (Europe) Limited
    Inventor: Stafford T. Screen
  • Patent number: D288287
    Type: Grant
    Filed: September 13, 1984
    Date of Patent: February 17, 1987
    Assignee: Colson Castors (Europe) Limited
    Inventor: Stafford T. Screen
  • Patent number: D310622
    Type: Grant
    Filed: July 21, 1986
    Date of Patent: September 18, 1990
    Assignee: Colson Castors (Europe) Limited
    Inventor: Stafford T. Screen
  • Patent number: D313342
    Type: Grant
    Filed: December 28, 1987
    Date of Patent: January 1, 1991
    Assignee: Colson Castors (Europe) Limited
    Inventor: Stafford T. Screen
  • Patent number: D378657
    Type: Grant
    Filed: November 17, 1995
    Date of Patent: April 1, 1997
    Assignee: Colson Castors Limited
    Inventor: Stafford T. Screen