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Class Information
Number: 417/444
Name: Pumps > Expansible chamber type > Pressure responsive distributor opened responsive to pumping member position > Distributor in piston
Description: Apparatus in which the pressure responsive distributor which is moved to open position is located on or carried by a piston-type pumping member (includes diaphragm-type pumping member).
Sub-classes under this class:
Patents under this class:
| Patent Number |
Title Of Patent |
Date Issued |
| 6347668 |
Relievable check valve assembly for oil wells and water wells |
Feb. 19, 2002 |
| 6099274 |
Pump to surface pump |
Aug. 8, 2000 |
| 5941311 |
Down-hole, production pump and circulation system |
Aug. 24, 1999 |
| 5655604 |
Down-hole, production pump and circulation system |
Aug. 12, 1997 |
| 5642990 |
Traveling valve ball displacing tool |
Jul. 1, 1997 |
| 5382142 |
Wall pump having backwash valve actuator |
Jan. 17, 1995 |
| 5249936 |
Downhold reciprocating pump with automatically trippable travelling valve for prevention of gas lock |
Oct. 5, 1993 |
| 5141411 |
Center-anchored, rod actuated pump |
Aug. 25, 1992 |
| 4907953 |
Locking gas equalizer assembly |
Mar. 13, 1990 |
| RE33163 |
Gas equalizer for downhole pump |
Feb. 13, 1990 |
| 4876558 |
Pump device and an ink jet recording apparatus having the pump device |
Oct. 24, 1989 |
| 4867242 |
Method and apparatus for breaking gas lock in oil well pumps |
Sep. 19, 1989 |
| 4781547 |
Gas equalizer for downhole pump |
Nov. 1, 1988 |
| 4662831 |
Apparatus for fracturing earth formations while pumping formation fluids |
May. 5, 1987 |
| 4648998 |
Charge forming apparatus |
Mar. 10, 1987 |
| 4636150 |
Low power electromagnetic pump |
Jan. 13, 1987 |
| 4569641 |
Low power electromagnetic pump |
Feb. 11, 1986 |
| 4568250 |
Low power electromagnetic pump |
Feb. 4, 1986 |
| 4561828 |
Pump for forwarding liquids |
Dec. 31, 1985 |
| 4557668 |
Down hole pump having a gas release valve |
Dec. 10, 1985 |
| 4252507 |
Hand-actuatable pump assembly |
Feb. 24, 1981 |
| 4088425 |
Manually operated pump for disposable container |
May. 9, 1978 |
| 4087212 |
Traveling oil pump valve |
May. 2, 1978 |
| 4050860 |
Spray pump assembly |
Sep. 27, 1977 |
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