Fuel filter

Claim 2

A fuel filter having a first fuel zone (50, 152), a second fuel zone (52, 150), and a semipermeable baffle (44, 144); characterised in that the baffle (44, 144) has a plurality of overlapping layers (46) of filter media with each layer (46) spaced by at least the thickness of one of the layers from any adjacent layers to define a circuitous settling channel (48), the channel (48) proceeds from the first fuel zone (50, 152) to the second fuel zone (52, 150) and is open to allow contaminants to flow from the first fuel zone to the second fuel zone without passage through any of the layers (46) of filter media, and the semipermeable baffle (44, 144) is operable to allow fuel to flow from the first fuel zone to the second fuel zone by passage into one side and out an opposite side of one or more of layers (46) of the filter media such that the filter media preferentially slows contaminants to settle in the channel (48) for movement along the channel (48).

Claim 3

A fuel filter according to claim 1, wherein the baffle (44, 144) is spiral with two opposite ends and the layers are spirally extending flights.

Claim 4

A fuel filter according to claim 2, wherein one of the first and second fuel zones is an interior fuel zone (50, 150) disposed within the baffle (44, 144) and the other of the first and second fuel zones is an exterior fuel zone (52, 152) which is annular and dispsoed around the baffle (44, 144).

Claim 5

A fuel filter according to claim 3, wherein the fuel filter further comprises upper (30U, 13DU) and lower (30L, 130L) end caps made of impermeable material disposed at the opposite ends of the baffle (44, 144) to define upper and lower sealed boundaries of the channel (48).

Claim 6

A fuel filter according to claim 4, further comprising a filter housing (18, 118) having a top and a bottom and a head assembly (12) with a fuel inlet (14) and a fuel outlet (16), the head assembly (12) being mounted at the top of the filter housing (18, 118), and wherein the fuel filter (28) is mounted within the filter housing (18, 118) and the exterior fuel zone (52, 152) extends between the fuel filter (28) and the filter housing (18, 118) and offsets even an outermost point of the filter media from the filter housing (18, 118).

Claim 7

A fuel filter according to claim 5, further comprising a collection bowl (62, 162) removably attached at the bottom of the filter housing (18, 118) to receive contaminants separated from the fuel by the baffle (44, 144).

Claim 8

A fuel filter according to claim 6, operable with radially inward fuel flow through the baffle or operable with radially outward fuel flow through the baffle.

Claim 9

A fuel filter acording to claim 6, wherein the contaminant collection bowl (62, 162) includes an interior contaminant collection zone (66, 166) to receive contaminants from the interior fuel zone (50, 150) and a separate exterior contaminant collection zone (68) to receive contaminants from the exterior fuel zone (52, 152).

Claim 10

A fuel filter having a first fuel zone (50 152), a second fuel zone (52, 150), and a semipermeable baffle (44, 144); characterised in that the baffle has a plurality of overlapping layers (46) of filter media, each layer (46) is spaced from any adjacent layers (46) to define a circuitous settling channel (48), each layer has two opposite sides, the channel (48) proceeds from the first fuel zone to the second fuel zone and is open to allow contaminants to fllow from the first fuel zone to the second fuel zone without passage through any of the layers (46) of filter media, the semipermeable baffle (44, 144) is operable to allow fuel to flow from the first fuel zone (50 152) to the second fuel zone (52, 150) by passage into one side and out an opposite side of one or more of the layers (46) of the filter media such that the filter media preferentially slows contaminants to settle in the channel (48) for movement along the channel (48), and the baffle is spiral with two opposite ends and the layers are spirally extending flights.

Claim 11

A fuel filter having a first fuel zone (50 152), a second fuel zone (52, 150), and a semipermeable baffle (44, 144); characterised in that the baffle has a plurality of overlapping layers (46) of filter media, each layer (46) is spaced from any adjacent layers (46) to define a circuitous settling channel (48), each layer has two opposite sides, the channel (48) proceeds from the first fuel zone to the second fuel zone and is open to allow contaminants to fllow from the first fuel zone to the second fuel zone without passage through any of the layers (46) of filter media, the semipermeable baffle (44, 144) is operable to allow fuel to flow from the first fuel zone (50 152) to the second fuel zone (52, 150) by passage into one side and out an opposite side of one or more of the layers (46) of the filter media such that the filter media preferentially slows contaminants to settle in the channel (48) for movement along the channel (48), and the baffle is spiral with two opposite ends and the layers are spirally extending flights.

Claim 12

A fuel filter according to claim 9, further comprising a filter housing (18, 118) having a top and a bottom and a head assembly (12) with a fuel inlet and a fuel outlet, the head assembly being mounted at the top of the filter housing (18, 118), and the fuel filter (28) being mounted within the filter housing (18, 118), and wherein the fuel inlet and the fuel outlet are operable respectively to feed fuel into and out of the filter housing from above, and further comprising at least a first contaminant collection zone (68, 168) disposed below the baffle (44, 144).

Claim 13

A fuel filter according to claim 10, wherein one of the first and second fuel zones is an interior fuel zone (50, 150) disposed within the baffle (44, 144) and the other (52, 152) of the first and second fuel zones is an exterior fuel zone which is annular and isposed around the baffle (44, 144), and wherein the fuel filter (28) further comprises upper (30U, 130U) and lower (30L, 130L) end caps made of impermeable material disposed at the opposite ends of the baffle (44, 144) to define upper and lower sealed boundaries of the channel (48).

Claim 14

A fuel filter according to claim 11, wherein the first contaminant collection zone (68, 168) is located in a collection bowl (62) removably attached at the bottom of the filter housing (18, 118) and the first contaminant collection zone (168) is disposed to receive contaminants passing between the lower end cap (30L, 130L) and a lower portion of the wall (18, 118) of the filter housing.

Claim 15

A fuel filter according to claim 12, wherein the fuel filter (28) is a cartridge unit removably mounted in the filter housing (18, 118).

Claim 16

A fuel filter according to claim 9, wherein one of the first and second fuel zones is an interior fuel zone (50, 150) disposed within the baffle (44, 144) and the other of the first and second fuel zones is an exterior fuel zone (52, 152) which is annular and disposed around the baffle (44, 144).

Claim 17

A fuel filter according to claim 14, wherein the fuel filter further comprises upper and lower end caps made of impermeable material disposed at the opposite ends of the baffle to define upper and lower sealed boundaries of the channel (48).

Claim 18

A fuel filter according to claim 15, wherein the upper end cap has an upper fuel port hole (42, 208) above the interior fuel zone (50, 150).

Claim 19

A fuel filter according to claim 16, wherein the lower end cap has a lower contaminant exit hole below the interior fuel zone.

Claim 20

A fuel filter according to claim 16, wherein the lower end cap includes an annular central mating means (220N) operable for mating with a contaminant collection bowl (102).

Claim 21

A fuel filter according to claim 18, wherein the fuel filter (28) is a cartridge unit removably mounted in the filter housing (18, 118), and wherein each layer is spaced by at least the thickness of one of the layers from any adjacent layers.

Claim 22

A fuel filter according to claim 9, further comprising a filter housing and wherein the baffle (44, 144) is fixed in position relative to the filter housing.