Volumetric pump shift bottoming detector

• US 5,618,163 A
• Filed: 06/06/1995
• Issued: 04/08/1997
• Est. Priority Date: 11/23/1993
• Status: Expired due to Term

• Current Assignee: Sterling Investments LC
• Original Assignee: Sarcos Group
• Inventors: Jacobsen, Stephen C., Davis, Clark C.
• Primary Examiner(s): Vrablik, John J.
• Assistant Examiner(s): Korytnyk, Peter G.
• Application Number:
  US08/467,032
• Time in Patent Office: 672 Days
• Field of Search: 92/5 R, 92/168, 417/63, 417/540, 60/560, 60/563, 60/565, 60/534
• US Class Current: 417/63
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: F04B 17/00 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F04B 17/03 driven by electric motors
• CPC Class Codes: F04B 2201/1208 Angular position of the shaft
• CPC Class Codes: F04B 2205/05 Pressure after the pump outlet
• CPC Class Codes: F04B 49/12 by varying the length of stroke of the working members
• CPC Class Codes: F04B 53/02 Packing the free space between cylinders and pistons
• CPC Class Codes: F04B 53/164 Stoffing boxes
• CPC Class Codes: F04B 7/0015 and having a slidable movement
• CPC Class Codes: F04B 9/02 the means being mechanical
• CPC Class Codes: F04B 9/045 the means being eccentrics
• CPC Class Codes: F05C 2225/04 PTFE [PolyTetraFluorEthylene]
• CPC Class Codes: F16K 41/12 with approximately flat diaphragm
• CPC Class Codes: Y10T 137/791 Ball valves
• CPC Class Codes: Y10T 137/86228 With communicating opening in common walls of tanks or compartments
• CPC Class Codes: Y10T 137/86799 With internal flow passage
• CPC Class Codes: Y10T 137/86879 Reciprocating valve unit
• CPC Class Codes: Y10T 137/87708 With common valve operator

Abstract

A bottoming detector for detecting the movement of a pump shaft beyond a pre-determined distance within a cylinder is disclosed. The pump has a housing defining an elongate cavity filled with fluid, a resilient sheet with an aperture in alignment with the cavity which divides the cavity into first and second compartments, and an elongate shaft disposed within the first compartment of the cavity such that it may be moved into and out of the aperture in the sheet to cause pressure fluctuations in the second compartment. There is also a chamber in fluid communication with the second compartment. In the chamber there is actuating means responsive to excessive pressure in the chamber, that actuates a switch to indicate that the shaft has reached a certain distance into the second compartment.

Claims

1. A pump bottoming detector comprising:

a housing defining an elongate cavity therein, said cavity being adapted to be filled with fluid;

a resilient sheet of material disposed in the cavity, said sheet including an aperture positioned in alignment with the cavity, said sheet dividing the cavity into first and second compartments;

a moveable elongate shaft disposed within the first compartment of the cavity such that it may be moved into and out of the aperture in the resilient sheet, to thereby alternately cause greater and lesser fluid pressure in the second compartment to move the fluid in a pumping action;

a fluid chamber disposed in fluid communication with the second compartment;

actuating means responsive to fluid pressure in the fluid chamber exceeding a certain level for actuating a switch adjacent the fluid chamber, to thereby indicate that the shaft has been moved a certain distance through the aperture in the sheet into the second compartment.