Stephen Michael Graham

US Patent:

7686595, Mar 30, 2010

Filed:

Dec 12, 2005

Appl. No.:

11/301011

Inventors:

Stephen Graham - El Sobrante CA, US

International Classification:

F04B 17/00

US Classification:

4174131

Abstract:

A high pressure metering pump employs a flexible diaphragm extending radially from a piston as the moving pump element. The diaphragm is secured by an annular anvil at its periphery to form a high pressure seal, and the center of the diaphragm is driven reciprocally by a mechanically driven piston. A support assembly for the diaphragm includes a moveable metal ring concentric about the piston and an elastic, resilient ring concentric about the piston and interposed between the metal ring and the diaphragm. The elastic resilient ring is formed of a material such as neoprene, Viton, or the like to mediate and distribute the force between the diaphragm and the metal ring. This assembly allows the diaphragm membrane to support the high pressures that are prevalent in HPLC.

US Patent:

20020129702, Sep 19, 2002

Filed:

Mar 14, 2001

Appl. No.:

09/808647

Inventors:

Stephen Graham - El Sobrante CA, US

International Classification:

F16J015/18

US Classification:

092/168000

Abstract:

A pump includes a piston rod and precision bearings that eliminate radial movement of the piston rod while permitting reciprocal axial translation. A piston extends axially from the piston rod, and is received in a cylinder in a pump head. A static seal assembly includes an annular ring received about the piston in a leakproof sliding engagement, the ring being formed of a soft polymer material. The annular ring is encapsulated in an outer ring formed of a stiff plastic material, defining a self-contained seal cartridge. The outer ring is dimensioned to be received in the pump head in a cylindrical recess that permits radial freedom relative to the axis of the cylinder. To assemble the pump, the seal cartridge is first assembled to the piston, thus assuring that the seal is aligned with the piston. Thereafter, the head is assembled to the pump body, the piston being inserted in the cylinder and the seal cartridge being received with clearance in the recess. Subsequently, the head is tightened, immobilizing the seal cartridge in the aligned relationship with the piston.

US Patent:

45521824, Nov 12, 1985

Filed:

Aug 13, 1984

Appl. No.:

6/640065

Inventors:

Stephen H. Graham - Alameda CA

Assignee:

Varian Associates, Inc. - Palo Alto CA

International Classification:

F16L 5504

US Classification:

138 30

Abstract:

A hydraulic pulse dampener has two diaphragms, each positioned opposite a recess formed in the housing. The regions between the diaphragms and the associated recesses are sealed from the fluid which flows through the dampener so that a rise in pressure in the fluid may cause each diaphragm to flex towards the recess behind until it may completely nest in it. The diaphragms are designed differently so that they will begin to flex and take a completely nested position in different pressure ranges.

US Patent:

45482403, Oct 22, 1985

Filed:

Aug 13, 1984

Appl. No.:

6/640061

Inventors:

Stephen H. Graham - Alameda CA

Assignee:

Varian Associates, Inc. - Palo Alto CA

International Classification:

F16L 5504

US Classification:

138 30

Abstract:

A hydraulic pulse dampener of liquid compressibility type has a flexible tubing wound around a form within a liquid-tight housing filled with a compressibility liquid and a stiff diaphragm placed adjacent a recess formed in a receiving member. As the fluid flowing inside the tubing experiences pressure pulses, the walls of the tubing expand and transmit the pulse energy through the compressibility liquid and causes the diaphragm to gradually flex towards the recess until it may completely nest in it. The recess in the receiving member preferably has a central flat portion so that the flexing diaphragm will first contact the receiving member at the center and the nesting will spread outwardly therefrom.