Self-compensating diaphragm pump

Claim 2

Self-compensating hydraulic diaphRagm apparatus comprising: a flexible diaphragm enclosure means in sealing relationship with said diaphragm defining a hydraulic chamber adjacent said diaphragm, piston means in substantially fluid-tight relationship with said hydraulic chamber, first fluid passageway means connectible to an external reservoir, and valve means connected to said diaphragm for providing fluid communication between said hydraulic chamber and said fluid passageway means when the distance between said diaphragm and said piston means is less than a predetermined distance.

Claim 3

The combination of claim 1 wherein said valve means comprises central passageway means through said piston means and lateral second fluid passageway means through said piston means for providing fluid communication between said central passageway means and said first fluid passageway means, and stem means fixed to said diaphragm and extending into said central passageway.

Claim 4

The combination of claim 2 wherein said stem means comprises an elongated member having an end portion including a boss defined by a constricted neck portion with said boss positioned adjacent to said lateral second fluid passageway means, said stem means having an artery communicating between the end of said stem means, said neck portion and said hydraulic chamber.

Claim 5

The combination of claim 1 wherein said self-compensating hydraulic apparatus is pump apparatus and said enclosure means further comprises pumping chamber means adjacent the other surface of said diaphragm, said pumping chamber means including an inlet and an outlet.

Claim 6

The combination of claim 2 wherein said piston means comprises a piston reciprocating between predetermined limits.

Claim 7

The combination of claim 5 further comprising means for providing a tensioning force between said piston and said diaphragm.

Claim 8

The combination of claim 6 wherein said first fluid passageway means comprises a relieved area in the inner wall of said enclosure means and a lateral passageway through the wall of said enclosure means.

Claim 9

The combination of claim 6 wherein said diaphragm is a rolling seal diaphragm.

Claim 10

The combination of claim 6 wherein said diaphragm is a semi-rigid metal diaphragm.

Claim 11

The combination of claim 5 wherein said tensioning force means comprises a second diaphragm.

Claim 12

The combination of claim 6 wherein said central passageway means comprises an aperture in the direction of the axis of reciprocation of said piston.

Claim 13

The combination of claim 2 further comprising an adjustable member in a fluid tight relationship with the end of said piston means opposite said stem means for providing an adjustable central passageway volume.

Claim 14

Self-compensating hydraulic pumping apparatus comprising a floating pumping member, enclosure means in sealing relationship with said floating pumping member defining a hydraulic chamber adjacent said floating pumping member, reciprocating piston means in substantially fluid tight relationship with said hydraulic chamber, fluid passageway means connectible to an external reservoir, valve means connected to said floating pumping member for providing fluid communication between said hydraulic chamber and said fluid passageway means when the distance between said floating pumping member and said fluid passageway means is less than a predetermined distance.

Claim 15

Self-compensating hydraulic pumping apparatus comprising a floating pumping member, enclosure means in sealing relationship with said floating pumping member defining a hydraulic chamber adjacent said floating pumping member, reciprocating piston means in substantially fluid tight relationship with said hydraulic chamber, fluid passageway means connectible to an external reservoir, valve means connected to said floating pumping member for providing fluid communication between said hydraulic chamber and said fluid passageway means when the distance between said floating pumping member and said fluid passageway means is less than a predetermined distance.

Claim 16

The combination of claim 13 characterized further in that said valve means connecting to said floating pumping member comprises valve means for providing fluid communication between said hydraulic chamber and said fluid passageway means when the distance between said floating pumping member and said fluid passageway means is greater than a predetermined distance.

Claim 17

The combination of claim 13 further comprising means extending through said enclosure means for indicating the position of said floating pumping member.

Claim 18

The combination of claim 13 further comprising adjustable member means for varying the voLume of said hydraulic chamber.

Claim 19

The apparatus of claim 1 in which said valve means comprises a valve element physically connected to said diaphragm movable therewith and extending into said hydraulic chamber from said diaphragm, a bore receiving a portion of said element, and first and second valve portions on said valve element spaced apart from each other longitudinally of said valve element with said valve portions positioned with respect to said bore to open and close communication between said reservoir and said chamber.

Claim 20

The apparatus of claim 17 in which said bore is located in said piston means.

Claim 21

The apparatus of claim 17 in which said enclosure means includes a stationary wall facing said diaphragm, said bore is located in said wall, and said piston is mounted in said enclosure means for reciprocation along a direction generally perpendicular to said stem.