Patents by Inventor Dennis H. Chaddock

Dennis H. Chaddock 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: 4317254
    Abstract: A door closer includes a tension member comprising spaced shafts acted by springs and connected to articulated chains which are coupled to an anchor plate secured to the door frame. Movement of the shafts is under the control of a uni-directionally operative fluid-filled damper having a piston carried by a piston rod which is connected to a cross head slidably mounted on the shafts and held against abutment washers by the springs. The damper serves to regulate the rate of movement of a door in the direction of closure without restricting significantly the rate of movement in the direction of opening. A fluid by-pass is provided in the damper by a rebate formed in the cylinder so that as the piston approaches the end of the cylinder over the final part of the closure movement the restraint imposed by the damper is relieved.
    Type: Grant
    Filed: March 20, 1980
    Date of Patent: March 2, 1982
    Assignee: Perkins & Powell Limited
    Inventor: Dennis H. Chaddock