Compressible baffle for a fuel tank

1. A baffle for mounting in a fuel tank having a top wall and a bottom wall with an access hole formed through said top wall, said baffle comprising:

a) a sidewall having an initial sidewall diameter larger than the access hole in the top wall of the tank;

b) an interior space within said sidewall; and

c) a floor closing a lower end of said sidewall and having an initial floor diameter larger than the access hole in the top wall of the tank; wherein

d) said floor and said sidewall are both formed from flexible materials so as to be radially compressible from their said initial diameters to respective compressed diameters smaller than the access hole such that said baffle is insertable into the tank through the access hole in the top wall of the tank.

2. The baffle as in claim 1 in combination with an in-tank fuel pump positioned in said interior space.

3. The baffle as in claim 1 in combination with a fuel pickup for an externally mounted pump positioned in said interior space.

4. The baffle as in claim 1 wherein said sidewall includes a core of compressible foam.

5. The baffle as in claim 4 wherein said compressible foam provides an expansive force which urges said sidewall back toward its initial diameter upon insertion into the tank.

6. The baffle as in claim 5 and further including a skin impermeable to the liquid and covering at least part of said sidewall.

7. The baffle as in claim 6 wherein said skin covers a lower part of said sidewall and has an upper margin such that liquid in the tank can flow over said skin and through said foam material of said sidewall to said interior space when a liquid level in the tank is higher than said upper margin of said skin.

8. The baffle as in claim 7 wherein said skin and said floor of said baffle are integrally molded to form a cup covering a lower portion of said core.

9. The baffle as in claim 7 wherein at least one opening is formed in said skin below said upper margin such that liquid in the tank can flow through said at least one opening when a liquid level in the tank is lower than said upper margin of said skin.

10. The baffle as in claim 9 wherein the size of said at least one opening is sized to impede liquid from flowing from said interior space of said baffle out to the tank during transient periods when the liquid sloshes away from said baffle.

11. The baffle as in claim 6 wherein said skin includes:

a) at least one first opening sized and positioned to allow liquid in the tank to flow freely through said at least one first opening to said interior space of said baffle when a liquid level in the tank is above a selected level; and

b) at least one second opening sized and positioned to allow liquid in the tank to flow through said at least one second opening to said interior space when a liquid level in the tank is below said selected level and further sized to impede liquid from flowing from said interior space out to the tank during transient periods when the liquid sloshes away from said baffle.

12. The baffle as in claim 4 wherein said compressible foam is permeable to a liquid in the tank.

13. The baffle as in claim 4 wherein said sidewall is longitudinally compressible from a first length in a relaxed state to a shorter, second length, said first length selected such that said sidewall is at least partially compressed when fitted in the tank and extending between the top wall and the bottom wall of the tank; and wherein expansive force of said foam material biases said sidewall toward its first length when said sidewall is at least partially compressed.

14. The baffle as in claim 1 wherein said sidewall is longitudinally compressible from a first length in a relaxed state to a shorter, second length, said first length selected such that said sidewall is at least partially compressed when fitted in the tank and extending between the top wall and the bottom wall of the tank; and

wherein said baffle further includes biasing means for biasing said sidewall toward its first length when said sidewall is at least partially compressed.

15. The baffle as in claim 14 wherein said biasing means is a spring.

16. The baffle as in claim 14 wherein said flexible material includes a core of compressible foam and said biasing means is provided by an expansive force of said compressible foam.

17. A baffle for mounting in a fuel tank having a top wall and a bottom wall with an access hole formed through said top wall, said baffle comprising:

a) a sidewall having a core of flexible foam material, said sidewall having an initial diameter in a relaxed state larger than the access hole in the top wall of the tank; and

b) an interior space within said sidewall; wherein

c) said sidewall is radially compressible from said initial diameter to a compressed diameter smaller than the access hole such that said baffle is insertable into the tank through the access hole, an expansive force of said foam material urging said sidewall back toward its initial diameter upon insertion into the tank.

18. The baffle as in claim 17 in combination with an in-tank fuel pump positioned in said interior space.

19. The baffle as in claim 17 in combination with a fuel pickup for an externally mounted pump positioned in said interior space.

20. The baffle as in claim 17 wherein said foam material is permeable to a liquid and said baffle further includes a skin impermeable to the liquid covering at least part of said sidewall.

21. The baffle as in claim 20 wherein said skin covers a lower part of said sidewall and has an upper margin such that liquid in the tank can flow over said skin and through said foam material of said sidewall to said interior space when a liquid level in the tank is higher than said upper margin of said skin.

22. The baffle as in claim 21 and further including a floor closing a lower end of said baffle.

23. The baffle as in claim 22 wherein said floor is formed of a flexible material so as to also be radially compressible from an initial diameter greater than the diameter of the access hole to a compressed diameter smaller than the diameter of the access hole.

24. The baffle as in claim 23 wherein said skin and said floor of said baffle are integrally molded to form a cup covering a lower portion of said core.

25. The baffle as in claim 17 wherein said sidewall is longitudinally compressible from a first length in a relaxed state to a shorter, second length, said first length selected such that said sidewall is at least partially compressed when fitted in the tank and extending between the top wall and the bottom wall of the tank; and wherein expansive force of said foam material urges said sidewall toward its first length when said sidewall is at least partially compressed.

26. A baffle for mounting in a fuel tank, said baffle having a sidewall, a floor extending generally transverse to said sidewall and an interior space within said sidewall, said sidewall formed of a flexible material longitudinally compressible from a first length in a relaxed state to a shorter, second length; and biasing means for biasing said sidewall toward its first length and wherein said baffle is sufficiently radially compressible along its entire length, including across the floor thereof, to fit through a hole which is smaller in diameter than an outside diameter of said baffle in its radially uncompressed state.

27. The baffle as in claim 26 in combination with a fuel tank wherein the tank has a top wall and a bottom wall and said first length of said sidewall of said baffle is selected such that said sidewall is at least partially compressed when fitted in the tank and extending between the top wall and the bottom wall of the tank.

28. The baffle as in claim 26 in combination with an in-tank fuel pump positioned in said interior space.

29. The baffle as in claim 26 in combination with a fuel pickup for an externally mounted pump positioned in said interior space.

30. The baffle as in claim 26 wherein said biasing means is a spring.

31. The baffle as in claim 26 wherein said flexible material includes a core of compressible foam and said biasing means is provided by an expansive force of said compressible foam.

32. The baffle as in claim 26 wherein said flexible material forming said sidewall comprises a bladder defining a cavity, said cavity receiving a filling material which expands said bladder from a collapsed condition when unfilled to an expanded condition when filled; said filling material comprising said biasing means for biasing said sidewall toward its first length.

33. The baffle as in claim 32 wherein said filling material is selected from the group consisting of a gas, an expandable foam, and a gel.

34. The baffle as in claim 32 wherein said filling material is pressurized.