Filter assembly with lockable lug means

Claim 1

A filter/coalescer assembly for mounting in a fuel tank comprising a base for supporting and providing fluid connection to a removable filter cartridge, said base being adapted for mounting at a port of said fuel tank and having a hollow connecting end for mating with said cartridge, a removable filter cartridge comprising a cylindrical filter medium and having a connecting end shaped to mate coaxially with said end of said base in a rotatable, telescopic relationship, said filter medium being adapted for inside-out flow, thereby causing said cartridge to be biased away from said base in use, said filter medium including material causing coalescing of water in fuel passing through said medium, the telescopically related mating ends of said base and cartridge providing radially opposed surfaces of circular cross section about the mutual axis of the connecting ends of said base and cartridge, the connecting end of one of said base and said cartridge having lug means extending radially toward the end of the other, the other said connecting end having corresponding passage means for lockably receiving said lug means, said passage means extending in a first circumferential direction along a first circumferential path at a first axial position to an angular position and in an axial direction from said first circumferential path at said angular position to a locked position at a second axial position that is different from said first axial position, there being a stop member at a position along a second circumferential path at said second axial position such that said lug means is prevented from circumferential movement along said second circumferential path in a second circumferential direction opposite to said first circumferential direction, a circular elastomeric sealing ring providing a radial seal between said circular cross-section surfaces, preventing liquid flow past it between said telescopic ends, and a locking mechanism biasing said lug means relative to said passage means in said axial direction into said locked position, said biasing being in the direction to cause said cartridge to be biased away from said base, whereby said cartridge can be easily secured to said base and removed from said base, and unintended disconnection of said cartridge from said base owing to vibration is avoided.