Patents by Inventor Colin R. Keefer

Colin R. Keefer 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: 4967045
    Abstract: A normally-closed pin switch mountable on a vertical wall and adapted to open only when actuated by a movable closure member. The switch includes a metal bracket defined by a generally-rectangular mounting plate having mounting holes adjacent either end thereof and a ledge cantilevered from the upper edge of the plate at its midsection whereby the bracket may be secured to the vertical wall to position the ledge in a horizontal plane. Integral with the ledge and projecting therebelow is a hollow metal cylinder whose upper end registers with a port formed in the ledge and whose lower end acts as the fixed contact of the switch. Slidably received in the cylinder is a plunger rod of insulation material, the lower section of the rod extending through the lower end of the cylinder and terminating in a contact acting as the movable contact of the switch. The rod is spring-biased to normally urge the movable contact into engagement with the fixed contact to close the switch.
    Type: Grant
    Filed: January 2, 1990
    Date of Patent: October 30, 1990
    Assignee: Harrison Electronic Systems, Inc.
    Inventor: Colin R. Keefer