Patents by Inventor Donald H. Walker

Donald H. Walker 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: 4220446
    Abstract: An attachable cleaning agent dispenser for retrofit use in combination with a conventional dental handpiece including a frame, gripping members for removably attaching the frame to a dental handpiece, a reservoir for containing a cleaning agent with the reservoir mounted on the frame, a dispensing orifice mountable adjacent a cleaning tool on the dental handpiece, a cleaning agent flow passageway connecting the reservoir and the orifice, a pneumatic piston slidable within the reservoir for ejecting cleaning agent from the reservoir, into the passageway, and out the orifice when pneumatic pressure is applied to the piston by finger control by an operator of the handpiece.
    Type: Grant
    Filed: November 29, 1978
    Date of Patent: September 2, 1980
    Inventor: Donald H. Walker
  • Patent number: 4202600
    Abstract: Retroreflective sheeting having a plurality of retroreflective cube corner prisms distributed over one of its surfaces is described. The prisms are disposed in a planar array having a plurality of zones of prisms having differing angular orientations such that the zones have differing retroreflective brightness when illuminated by a light beam at a high angle of incidence. The zones are small enough to be substantially unresolvable by the unaided human eye at the expected viewing distances, so that the sheeting appears to have uniform retroreflective brightness when viewed at a high angle of incidence.
    Type: Grant
    Filed: April 24, 1978
    Date of Patent: May 13, 1980
    Assignee: Avery International Corporation
    Inventors: Thomas F. Burke, Donald H. Walker