Liquid filter system
An oil filter for an internal combustion engine with a cup-shaped housing that is releasably connectable to a receiving head. The housing has a first interlocking element that extends across at least a portion of the outer circumference of the housing and is interrupted by at least one axially extending recess. The filter element has a liquid-tight canister provided on its outer surface with second interlocking elements, which fit into the recesses of corresponding first interlocking elements when the filter element is installed in the housing.
1. A liquid filter system comprising receiving head, a cup-shaped housing releasably connectable to the receiving head, and a filter element disposed inside the housing, wherein the housing is provided with a plurality of first interlocking elements that extend across at least a portion of the outer circumference of the housing or across a lower edge of the housing, each said interlocking element being interrupted by at least one axially extending recess or having a laterally adjoining axially extending recess, and wherein said filter element comprises a canister provided on an outer surface thereof or at a lower edge thereof with a plurality of second interlocking elements which are received in the axially extending recesses of the first interlocking elements when the filter element is installed in the housing.
2. A liquid filter system according to claim 1 , wherein the first and second interlocking elements complement each other to form a web with an inclined cam surface on the outer circumference of the housing, and each such web is received into an arcuate recess in the receiving head to produce a bayonet connection between the webs and the arcuate recesses.
3. A liquid filter system according to claim 1 , wherein said second interlocking elements have an outside diameter which corresponds to the outside diameter of the first interlocking elements, and an arc length which corresponds to the arc length of the axially extending recess of the first interlocking elements.
4. A liquid filter system according to claim 1 , wherein at least one annular sealing element is disposed between the canister of the filter element and the cup-shaped housing.
5. A liquid filter system according to claim 4 , wherein the annular sealing element comprises an elastomer sealing collar formed at the outer circumference of the filter element.
6. A liquid filter system according to claim 1 , wherein the axially-extending recesses in the first interlocking elements and the second interlocking elements are arranged in an unsymmetrical angular distribution around the circumference of the filter.
7. A liquid filter system according to claim 6 , wherein the webs formed by the first and second interlocking elements are arranged in a symmetrical angular distribution around the circumference of the filter.
8. A liquid filter system according to claim 1 , wherein the filter element comprises at least one handle element on the inflow side of the canister.
9. A liquid filter system according to claim 8 , wherein said at least one handle element comprises a pair of semicircular partial handle elements, which are flexibly interconnected by a film hinge along a diameter of the filter element.
10. A liquid filter system according to claim 1 , wherein the filter element comprises a filter insert member wound from a semipermeable flat structure consisting of a pleated filter layer, which on one side is bonded to a cover layer along its folded edges.
11. A liquid filter system according to claim 2 , wherein at least one radially displaceable, spring-mounted detent pin is provided on the receiving head and protrudes into an arc-shaped recess, and the webs each have an inclined cam surface on at least one lateral edge for deflecting the detent pin.
12. A filter system according to claim 1 , wherein said filter is an oil filter or fuel filter for an internal combustion engine.
13. A filter system according to claim 1 , wherein said canister is a liquid-tight canister which completely encloses the filter element.