Patent ID: 6027319
Filing Date: 2000-02-22
Classification: F04B

Abstract:
A manually operated air pump of the type terminating in a valve for connection to a device to be inflated and comprising:a middle tube closed at one end;an inner tube concentrically positioned within said middle tube and communicating with said closed one end of said middle tube;an outer tube receiving said middle and inner tubes, said middle tube being moveable coaxially relative to said outer and inner tubes;a first seal at an end of said middle tube forming a moveable piston within said outer tube for driving air toward said device to be inflated;a second seal at an end of said inner tube forming a moveable piston within said middle tube for driving air through said inner tube into said device to be inflated, said second seal having a one way valve;said outer tube forming a chamber for selectively directing air from said outer tube into said device to be inflated or through an opening to ambient;a device for selectively closing and opening said chamber of said outer tube for either sealing or unsealing said chamber for corresponding high volume or high pressure operation of said pump.