Dry cleaning filter element assembly

Claim 2

A disposable filter cartridge for use with dry cleaning solvent comprising: means including a perforated cylindrical support tube adapted to receive through the perforations thereof solvent to be conditioned, a perforated center tube concentric with said support tube and having one end open for dispensing conditioned solvent therethrough, the perforations of said center tube formed by a generally cylindrical plastic grid of intersecting longitudinal and circular ribs, the uppermost and lowermost of said circular ribs forming the ends of said center tube, the perforations of said support tube and said center tube being in sequential flow relationship, annular imperforate end plate means at one end of said cartridge connected to said support tube and defining therewith a center cavity open at the other end of said cartridge, said means including said support tube and said end plate means forming an outer filter assembly, said end plate means having a slightly resilient lower bulkhead defining said one end of said center cavity and having an inner terminal edge in the center thereof forming on the outside surface thereof a sealing shoulder and an opening large enough to insertingly pass one end only of said center tube, the other end of said center tube being larger than said opening to prevent said other end from passing through said opening, an annular upper cover sealingly supported by said support tube at the other end of said cartridge for closing the open end of said center cavity, an endless plastic screen molded integral with said center tube and covering the perforations thereof, the plastic of said screen having a melting point temperature at least as high as the melting point temperature of the plastic of said grid, the longitudinal ribs of said grid alternately supporting said screen on the inside and outside thereof at spaced points around said center tube, the circular ribs of said grid supporting said screen on the outside thereof, the lowermost circular rib of said grid forming a first shoulder on one end of said center tube sealingly abutting the outside surface of said lower bulkhead around said terminal edge in a manner to seal said center cavity at said bulkhead when said center tube is generally perpendicular to said bulkhead, the uppermost circular rib of said grid forming a second shoulder on the other end of said center tube abutting the inside surface of said upper cover, activated carbon granules in said conditioning chamber for removing soluble matter from solvent flowing therethrough, and means locking said upper cover to said other end of said center tube when said upper cover is sealingly supported by said support tube, said locking means including a central port in said upper cover and a ferrule molded integral with the uppermost circular rib of said center tube, said ferrule having an annular terminal flange extending longitudinally from said second shoulder and in crimped together relationship with said upper cover around the central port, said center tube having a sufficiently shortened longitudinal dimension between said shoulders relative to said outer filter assembly so that in cooperation with the resilience of said bulkhead said center tube is maintained in tension between the outside surface of said lower bulkhead and the inside surface of said upper cover whereby to facilitate the sealing bias between said lower bulkhead and said first shoulder throughout the useful life of said filter cartridge.

Claim 3

The filter cartridge of claim 1 wherein the plastic of said screen and the plastic of said grid have the same melting point.

Claim 4

The filter cartridge of claim 2 wherein the plastic of said screen and the plastic of said grid is nylon.

Claim 5

The filter cartridge of claim 1 wherein said ferrule is a metal sleeve formed to interlock with said uppermost circular rib as the result of the integral molding therewith.

Claim 6

The filter cartridge of claim 1 wherein the plastic screen is made endless by completely enclosing the ends thereof in one of said longitudinal ribs.

Claim 7

A disposable filter cartridge for use with dry cleaning solvent comprising: a perforated cylindrical outer shell adapted to receive through the perforations thereof solvent to be filtered and conditioned, a perforated center tube concentric with said outer shell and having one end open for dispensing filtered and conditioned solvent therethrough, the perforations of said center tube formed by a generally cylindrical plastic grid of intersecting longitudinal and circular ribs, the uppermost and lowermost of said circular ribs forming the ends of said center tube, a perforated sheet metal support tube concentric with said outer shell and said center tube and interposed therebetween in a manner to place the perforations of said outer shell, support tube and center tube in sequential flow relationship, annular imperforate sheet metal end plate means at each end of said cartridge connecting said outer shell and said support tube in spaced relationship respectively along outer and inner peripheral edges of said end plate means to define an annular solvent filtering chamber and a center cavity, a tube of filter paper in said filtering chamber for removing particulate matter from solvent flowing therethrough, said outer shell, said support tube, said end plate means and said tube of filter paper forming an outer filter assembly, one of said end plate means having a slightly resilient lower bulkhead closing one end of said center cavity and having an inner terminal edge in the center thereof forming on the outside surface thereof a sealing shoulder and an opening large enough to insertingly pass one end only of said center tube, the other end of said center tube being larger than said opening to prevent said other end from passing through said opening, an upper cover having an outer edge sealingly engageable with the inner peripheral edge of the other of said end plate means and closing the other end of said center cavity, an endless plastic screen molded integral with said center tube and covering the perforations thereof, the longitudinal ribs of said grid supporting said screen on one side thereof at spaced points around said center tube, the circular ribs of said grid supporting said screen on the other side thereof, the lowermost circular rib of said grid forming a first shoulder on one end of said center tube sealingly abutting the outside surface of said lower bulkhead around said terminal edge in a manner to seal said center cavity at said bulkhead when said center tube is generally perpendicular to said bulkhead, the uppermost circular rib of said grid forming a second shoulder on the other end of said center tube abutting the inside surface of said upper cover, activated carbon granules in said conditioninG chamber for removing soluble matter from solvent flowing therethrough, and means locking said upper cover to said other end of said center tube when said upper cover is engaged with the inner peripheral edge of said other of said end plate means, said locking means including a central port in said upper cover and means molded integral with the uppermost circular rib of said center tube and engageable with said upper cover in a manner to seal said upper cover to said uppermost circular rib throughout the useful life of said filter cartridge, said center tube having a sufficiently shortened longitudinal dimension between said shoulders relative to said outer filter assembly that said center tube is maintained in tension between the outside surface of said lower bulkhead and the inside surface of said upper cover whereby to facilitate the sealing bias between said lower bulkhead and said first shoulder throughout the useful life of said filter cartridge.

Claim 8

A disposable filter cartridge for use with dry cleaning solvent comprising: a perforated cylindrical outer shell adapted to receive through the perforations thereof solvent to be filtered and conditioned, a perforated center tube concentric with said outer shell and having one end open for dispensing filtered and conditioned solvent therethrough, the perforations of said center tube formed by a generally cylindrical plastic grid of intersecting longitudinal and circular ribs, the uppermost and lowermost of said circular ribs forming the ends of said center tube, a perforated sheet metal support tube concentric with said outer shell and said center tube and interposed therebetween in a manner to place the perforations of said outer shell, support tube and center tube in sequential flow relationship, annular imperforate sheet metal end plate means at each end of said cartridge connecting said outer shell and said support tube in spaced relationship respectively along outer and inner peripheral edges of said end plate means to define an annular solvent filtering chamber and a center cavity, a tube of filter paper in said filtering chamber for removing particulate matter from solvent flowing therethrough, said outer shell, said support tube, said end plate means and said tube of filter paper forming an outer filter assembly, one of said end plate means having a slightly resilient lower bulkhead closing one end of said center cavity and having an inner terminal edge in the center thereof forming on the outside surface thereof a sealing shoulder and an opening large enough to insertingly pass one end only of said center tube, the other end of said center tube being larger than said opening to prevent said other end from passing through said opening, an upper cover having an outer edge sealingly engageable with the inner peripheral edge of the other of said end plate means and closing the other end of said center cavity, an endless plastic screen molded integral with said center tube and covering the perforations thereof, the longitudinal ribs of said grid supporting said screen on one side thereof at spaced points around said center tube, the circular ribs of said grid supporting said screen on the other side thereof, the lowermost circular rib of said grid forming a first shoulder on one end of said center tube sealingly abutting the outside surface of said lower bulkhead around said terminal edge in a manner to seal said center cavity at said bulkhead when said center tube is generally perpendicular to said bulkhead, the uppermost circular rib of said grid forming a second shoulder on the other end of said center tube abutting the inside surface of said upper cover, activated carbon granules in said conditioninG chamber for removing soluble matter from solvent flowing therethrough, and means locking said upper cover to said other end of said center tube when said upper cover is engaged with the inner peripheral edge of said other of said end plate means, said locking means including a central port in said upper cover and means molded integral with the uppermost circular rib of said center tube and engageable with said upper cover in a manner to seal said upper cover to said uppermost circular rib throughout the useful life of said filter cartridge, said center tube having a sufficiently shortened longitudinal dimension between said shoulders relative to said outer filter assembly that said center tube is maintained in tension between the outside surface of said lower bulkhead and the inside surface of said upper cover whereby to facilitate the sealing bias between said lower bulkhead and said first shoulder throughout the useful life of said filter cartridge.

Claim 9

The filter cartridge of claim 6 wherein the one end of said center tube open for dispensing includes a sizing adaptor in snap fastened relation therewith.

Claim 10

The filter cartridge of claim 6 wherein the plastic of said screen has a melting point temperature at least as high as the melting point temperature of the plastic of said grid.

Claim 11

The filter cartridge of claim 6 wherein said cartridge is substantially 14 inches long and said center tube is substantially 0.058 inch shorter than the stack-up of dimensions joining said outer filter assembly with said upper cover.