Patents by Inventor Derek Robertshaw

Derek Robertshaw 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).

  • Flush control
    Patent number: 4471498
    Abstract: Apparatus for controlling the flushing of a lavatory, for example in a mens urinal, comprises a source of water for flushing, a flush control valve SV wherein the valve is actuated in response to the usage of the lavatory, for example by means of door switch DS. In order that over-use of the device should be prevented in busy periods, a delay circuit D1 is provided to prevent a second actuation of the water supply solenoid valve within a preset period from a first actuation.
    Type: Grant
    Filed: January 8, 1982
    Date of Patent: September 18, 1984
    Assignee: Laycock Bros. Limited
    Inventor: Derek Robertshaw