Filter leaf core

Claim 2

A core for use in a pressure filter leaf in which a pair of filter screens or the like are disposed against opposite faces of the core, comprising a hard, resilient, flexible, reinforcing panel formed of fiber glass, a pair of imperforate, flexible rubber coating layers, said coating layers conforming to and being bonded to the opposite faces of said panel to form an integral structure, said coating layers each having a plurality of external, integral studs providing interconnecting surface channels on the faces of said core, the thickness of said layers intermediate said studs being substantially less than the thickness of said panel, whereby said layers and said panel have substantially the same coefficient of thermal expansion and the inherent resiliency of said fiber glass panel provides a structural memory which permits said core to flex under fluid pressures exerted thereon during use and to automatically return to its original planar shape upon removal of said pressures.

Claim 3

A core as set forth in claim 1 wherein said studs are arranged in a plurality of staggered rows providing irregular drainage channels.

Claim 4

A filter leaf core adapted to be mounted in a filter leaf frame between a pair of filter screens or the like for use in a pressurizable filter tank which operates to filter a fluid under pressure, wherein the improvement comprises: a reinforcement member of hard, resilient, fiberboard bending in response to said fluids under pressure and snapping back to its original position when the pressure of said fluid is relieved, a sheet of fiber glass matted material secured to one face of said fiberboard, aNd a pair of coating layers secured to each side of said reinforcing member, each of said layers having an irregular outer surface to provide a plurality of drainage channels opening into the marginal edges of the core and being relatively narrow in cross section in its area at the shallowest portion of said channels in comparison with the thickness of said reinforcement member.

Claim 5

A filter leaf core adapted to be mounted in a filter leaf frame between a pair of filter screens or the like for use in a pressurizable filter tank which operates to filter a fluid under pressure, wherein the improvement comprises: a reinforcement member of hard, resilient, fiberboard bending in response to said fluids under pressure and snapping back to its original position when the pressure of said fluid is relieved, a sheet of fiber glass matted material secured to one face of said fiberboard, aNd a pair of coating layers secured to each side of said reinforcing member, each of said layers having an irregular outer surface to provide a plurality of drainage channels opening into the marginal edges of the core and being relatively narrow in cross section in its area at the shallowest portion of said channels in comparison with the thickness of said reinforcement member.

Claim 6

A filter leaf core according to claim 3, further including a second sheet of fiber glass matted material secured to the opposite face of said fiberboard plate.

Claim 7

A filter leaf core adapted to be mounted in a filter frame between a pair of filter screens or the like for use in a pressurizable filter tank which operates to filter a fluid under pressure, comprising a reinforcing member of hard, resilient nonmetallic material at least partially composed of fiber glass and a fiberboard plate, said member bending in response to fluids under pressure and snapping back to its original position when said pressure is relieved, said fiberboard including means defining a plurality of apertures extending through said plate, said fiber glass comprising a pair of fiber glass laminate sheets disposed on opposite sides of said fiberboard and having integrally formed posts extending therebetween and through said holes, and a pair of coating layers secured to each side of said reinforcing member, each of said layers having an irregular outer surface to provide a plurality of drainage channels opening at the marginal edges of the core and being relatively narrow in cross section in the area at the shallowest portion of said channels in comparison to the thickness of said reinforcing member.

Claim 8

A filter leaf core adapted to be mounted in a filter frame between a pair of filter screens or the like for use in a pressurizable filter tank which operates to filter a fluid under pressure, comprising a reinforcing member of hard, resilient nonmetallic material at least partially composed of fiber glass and a fiberboard plate, said member bending in response to fluids under pressure and snapping back to its original position when said pressure is relieved, said fiberboard including means defining a plurality of apertures extending through said plate, said fiber glass comprising a pair of fiber glass laminate sheets disposed on opposite sides of said fiberboard and having integrally formed posts extending therebetween and through said holes, and a pair of coating layers secured to each side of said reinforcing member, each of said layers having an irregular outer surface to provide a plurality of drainage channels opening at the marginal edges of the core and being relatively narrow in cross section in the area at the shallowest portion of said channels in comparison to the thickness of said reinforcing member.