Patents Assigned to David P. Allen
  • Patent number: 5031555
    Abstract: A neutral buoyancy device, (NBD), includes a lift volume container, load suspension straps, control mechanism, handle, self-closing intake and exhaust valves and valve actuators. A high pressure air source is provided by attaching a pressure cylinder to the NBD or from the surface. The handle is attached to the control mechanism, which is positioned between the lift volume container and load. The control mechanism senses any net difference in lift and load forces and causes the intake valve to open automatically when the load increases, (or as the air volume and lift decrease during descent), and the exhaust valve to open automatically when the load decreases, (or as the air volume and lift increase during ascent). Both valves are self-closing. The user grasps the handle and is able to load or unload the NBD, or transport the load up, down or sideways underwater while neutral buoyancy is automatically maintained.
    Type: Grant
    Filed: February 1, 1990
    Date of Patent: July 16, 1991
    Assignee: David P. Allen
    Inventor: David P. Allen