Patents Assigned to Evan John and Sons (Kenfig Hill) Limited
  • Self-locking device for telescopic props
    Patent number: 3991964
    Abstract: A telescopic prop of the kind used for supporting formwork and scaffolding in building construction has a self-locking device which enables the prop to be locked at any desired extension without the use of the customary locking pins. The self-locking is effected through the action of a number of balls housed in an annular channel of downwardly tapering width, the balls jamming against the surface of the inner extension member of the prop, which may be a length of standard scaffolding tube.
    Type: Grant
    Filed: December 10, 1974
    Date of Patent: November 16, 1976
    Assignee: Evan John and Sons (Kenfig Hill) Limited
    Inventor: Stanley A. Christopher