Filter changing device for extrusion machines

Claim 2

A filter screen changing device comprising a cylindrical body member having a central axial passageway whereby the passageway at one end of said body member forms an entrance port for receiving a material to be filtered, a sleeve member slidably mounted on said body member and having an inwardly projecting flange means at one end thereof with a central aperture aligned with said passageway, said aperture forming an exit port for said device, a seat on the other end of said body member including guide means, a screen holder slidably positioned in said guide means for movement in a transverse direction, releasable clamping means for urging said flange means toward said other end of said body member for rigidly holding said screen holder between said seat and said flange means, means inhibiting relative rotation of said body member and sleeve member, and slot means in said sleeve member positioned in transverse alignment with said screen holder whereby said screen holder may be passed through said slot means into said guide means.

Claim 3

A filter screen changing device comprising a cylindrical body member having a central axial passageway, the passageway at one end of said body member forming an entrance port for said device, a sleeve member having one end axially slidably mounted on said body member, the other end of said sleeve member having inwardly extending flange means with a central aperture, whereby said aperture forms an exit port for said device, an annular seat surrounding said aperture on the inside of said sleeve member, seat means on the other end of said body member, said seat means having a central aperture aligned with said passageway, and a transversely extending recess, filter screen holder means mounted in said recess, releasable clamping means on said sleeve member for urging said annular seat toward said seat means for holding said screen holder means therebetween, slot means in said sleeve member transversely aligned with said screen holder means for inserting and withdrawing said holder means therethrough, and means for inhibiting relative rotation of said sleeve member and said body member.

Claim 4

A filter screen changing device comprising a cylindrical body member having a central axial passageway, the passageway at one end of said body member forming an entrance port for said device, a sleeve member having one end axially slidably mounted on said body member, the other end of said sleeve member having inwardly extending flange means with a central aperture, whereby said aperture forms an exit port for said device, an annular seat surrounding said aperture on the inside of said sleeve member, seat means on the other end of said body member, said seat means having a central aperture aligned with said passageway, and a transversely extending recess, filter screen holder means mounted in said recess, releasable clamping means on said sleeve member for urging said annular seat toward said seat means for holding said screen holder means therebetween, slot means in said sleeve member transversely aligned with said screen holder means for inserting and withdrawing said holder means therethrough, and means for inhibiting relative rotation of said sleeve member and said body member.

Claim 5

The filter screen changing device of claim 2 wherein said releasable clamping means comprises an outwardly extending first flange at said one end of said body member, said first flange having external threads, an outwardly extending flange on said one end of said sleeve member, a clamping ring having an internally extending flange engaging said second flange and internal threads engaging said external threads, and retaining ring means on said sleeve member for inhibiting relative axial movement between said clamping ring means and said sleeve member.

Claim 6

The filter screen changing device of claim 2 wherein said means inhibiting relative rotation comprises longitudinally extending key members on the external cylindrical surface of said body member, and longitudinally extending slots in said sleeve member and positioned to engage said key means.

Claim 7

The filter screen changing device of claim 2 wherein said recess in said seat means extends transversely of said device and has a pair of parallel spaced apart guide surfaces on opposite sides of the aperture, said screen holder means having a generally rectangular cross-section in a plane transverse of said device, whereby a pair of opposite edges of said holder means are slidably guidable by said guide surfaces.

Claim 8

The filter screen changing device of claim 5 wherein said holder means has a central aperture aligned with said passageway, and filter screen means positioned in said central aperture therein.

Claim 9

The filter screen changing device of claim 5 wherein the thickness of said holder means in the longitudinal direction of said device is greater than the depth of said recess, and one of the edges of said holder means has a projection positioned to inhibit placement of said holder means in said recess except when a determined face of said holder means is directed toward said seat means.

Claim 10

The filter screen changing device of claim 5 wherein said holder means has a central aperture for receiving filter screen means, and a recess at each end of said aperture of said holder means, and further comprising an aluminum sealing ring in each of said recesses of said holder means, said sealing rings having dimensions in the longitudinal direction of said device greater than the depth of said recesses.

Claim 11

The filter screen changing device of claim 5 wherein the central aperture of said seat means has an outwardly extending transition zone toward said holder means, and said annular seat has an inwardly extending transition zone toward the central aperture of said inwardly extending flange means of said sleeve member.

Claim 12

The filter screen changing device of claim 5 further comprising stop means in said recess for inhibiting movement of said holder means in said recess beyond a determined position in one direction.

Claim 13

The filter screen changing device of claim 2 further comprising a flat annular flange affixed to and coaxially aligned with said one end of said body member for forming a mounting flange, and an adapter ring mounted in the aperture of said flange and aligned with said passageway, said adapter ring having an inwardly extending transition toward said passageway.