Patents by Inventor John U. Chapman

John U. Chapman 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).

  • Improvements in and relating to roller doors
    Patent number: 5159967
    Abstract: A roller door assembly has means for tensioning same wherein a load is applied to a bottom edge of the roller and means for counterbalancing the weight of the door wherein a load is applied to the roller, the loads exerted by both said means being dependent on the amount of door off the roller.
    Type: Grant
    Filed: May 8, 1991
    Date of Patent: November 3, 1992
    Assignee: Clark Door Limited
    Inventors: Paul Ashley, John U. Chapman
  • Roller door assemblies
    Patent number: 5058651
    Abstract: A roller door assembly comprises a roller door having on its vertical edges spaced restraining members, and guides at each edge of the door including opposing members forming a gap therebetween. The restraining members are on one side of the gap with the door on the other side thereof, whereby upto a desired pressure or force on the door the restraining members cannot pass through said gaps but at said desired pressure or force the restraining members are compressed and/or the gap expends for the restraining members to pass through said gaps to release the door.
    Type: Grant
    Filed: December 22, 1989
    Date of Patent: October 22, 1991
    Assignee: Clark Door Limited
    Inventors: Paul Ashley, John U. Chapman