Claims
- 1. A fuel pressure pulse damper for a fuel pump comprising: a hollow body of a thin walled tube of a flexible and resilient plastic material having a pair of spaced apart ends, the wall of the tube being pinched together and permanently sealed adjacent each said end and in at least one portion between said ends to form in cooperation with the tube at least two elongate chambers therein, an elongate body of a resilient foam material disposed in each said chamber, a compressible gas hermetically sealed in each chamber, and said hollow body being in contact with fuel discharged by the pump so that said hollow body and each said body of resilient foam is compressed by pressure pulses in the discharged fuel to dampen the pressure pulses and steady the flow of fuel discharged from the fuel pump.
- 2. The damper of claim 1 wherein said hollow body is generally oval in cross section.
- 3. The damper of claim 1 which further comprises a rigid cage having at least one port for admitting fuel and said cage encircles, supports and carries said hollow body in the fuel pump.
- 4. The damper of claim 1 wherein said plastic material of said thin wall tube comprises polyester, nylon, or acetal.
- 5. The damper of claim 1 wherein said compressible gas in each said chamber is at superatmospheric pressure and the wall of said tube is heat sealed where pinched together.
- 6. The damper of claim 1 wherein the wall of the tube has a nominal thickness of about 0.002 to 0.05 of an inch.
- 7. The damper of claim 1 wherein in cross section the wall of the tube has an outside diameter in the range of about 0.1 to 0.5 of an inch.
- 8. The damper of claim 1 wherein when the damper is exposed to atmospheric pressure the gas hermetically sealed in each said chamber has a superatmospheric pressure which is in the range of 5% to 30% less than the nominal pressure of fuel discharged from the pump when operating under normal conditions.
- 9. The damper of claim 1 wherein the tube is disposed in the configuration of a discontinuous annular ring extending through an arcuate segment of more than 180.degree. and less than 360.degree..
- 10. The damper of claim 1 wherein said body of foam material has a low compression set.
- 11. The damper of claim 1 wherein said body of foam material has a compression set not greater than 10% as determined by ASTM specification D395.
- 12. The damper of claim 1 wherein said body of foam material has a compression set not greater than about 5% as determined by ASTM specification D395.
- 13. The damper of claim 1 wherein said body of foam is a plastic material which is highly resilient and has a low compression set which does not substantially deteriorate at operating temperatures up to 300.degree. F.
- 14. The damper of claim 1 wherein said body of foam material has a substantially uniform thickness and a generally rectangular cross section.
- 15. A fuel pressure pulse damper for a fuel pump comprising: a hollow body of a thin walled tube of a flexible and resilient plastic material having a pair of spaced apart ends, the wall of the tube being pinched together and permanently sealed adjacent each said end and in at least one portion between said ends to form in cooperation with the tube at least two chambers therein, a body of a resilient foam material disposed in each chamber, a compressible gas hermetically sealed in each said chamber, and said hollow body being constructed to be carried by the fuel pump in contact with fuel discharged by the pump so that said hollow body and each said body of resilient foam is compressed by pressure pulses in the discharged fuel to dampen the pressure pulses and steady the flow of fuel discharged from the pump.
- 16. A fuel pressure pulse damper in combination with a fuel pump comprising: a hollow body made from a thin wall tube of a flexible and resilient plastic material having a pair of initially open and spaced apart separate ends, the wall of the tube being pinched together and permanently sealed to form a permanent tube closure portion at least adjacent each said initially open separate end to form in cooperation with the tube at least one chamber therein between an associated pair of said closure portions, a compressible gas hermetically sealed in said at least one chamber at a superatmospheric pressure in the range of 5% to 30% less than a the nominal pressure of fuel discharged from the pump when in use, in cross section the wall of the tube having a nominal thickness in the range of 0.002 to 0.05 of an inch and an outside free-state diameter in the range of 0.1 to 0.5 of an inch, a body of a resilient and compressible foam material disposed in said chamber, said hollow body being carried by the fuel pump in contact with fuel discharged by the pump so that both said hollow body and said body of foam material are compressed by pressure pulses in the discharged fuel to dampen the pressure pulses and steady the flow of fuel discharged from the fuel pump, and a rigid cage having a plurality of ports for admitting fuel, and encircling, supporting and carrying said hollow body in the fuel pump.
REFERENCE TO A CO-PENDING APPLICATION
This is a continuation-in-part of U.S. patent application Ser. No. 08/116,911 filed on Sep. 7, 1993 and issued on Dec. 20, 1994 as U.S. Pat. No. 5,374,169.
US Referenced Citations (6)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
116911 |
Sep 1993 |
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