Patents by Inventor David Shrimpton

David Shrimpton 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: 5174411
    Abstract: A loft ladder which can be pivotally and slidably mounted to loft opening has counterbalancing means including a resiliently biased pivotal arm, connected to the loft ladder by a link member pivotally connected between the pivotal arm and the loft ladder to allow the ladder to turn about is pivotal connection to the loft opening over at least a limited extend. The arm has a two-stage resilient biasing spring offering a greater resilient force over part of the range of movement of the arm. A hand rail of the ladder is supported on a section of the ladder by spacers allowing the hand rail to be carried at a lateral distance from the ladder stile greater than the lateral space occupied by the counterbalance mechanism. A releasable catch for retaining two ladder parts in a selected position comprises two moveable catch members mounted on respective stiles, and interconnected together.
    Type: Grant
    Filed: September 26, 1991
    Date of Patent: December 29, 1992
    Assignee: Abru Aluminium Limited
    Inventors: David P. Oliver, David Shrimpton