Patents by Inventor David K. Mitchell

David K. Mitchell 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: 4628861
    Abstract: A new metering and proportioning apparatus for directly applying a two-component adhesive in a wood laminating process is described. The key element of the invention is a valve system regulating flow of resin and hardener to and from double-acting cylinder pumps. The new system eliminates conventional spool valve difficulties. Each component cylinder pump is supplied with a pair of 3-way ball valves which are manifolded to direct component flows. A pneumatic control system senses completion of a component discharge stroke and causes simultaneous reversal of the ball valve pair for discharge of component and refilling of the emptied side of the cylinder on the return stroke. A two-level optical sensor detects a workpiece and opens extruder head discharge. The sensor operates a modulating valve in the resin supply line as the workpiece proceeds ensuring even spread rate.
    Type: Grant
    Filed: December 12, 1985
    Date of Patent: December 16, 1986
    Assignee: Chembond Corporation
    Inventor: David K. Mitchell