Plate filter having a movable filter cloth

Claim 1

A plate filter having a length, comprising (a) a stand; (b) a plurality of filter plates supported on said stand in a parallel orientation and being shiftable parallel to said length; (c) means for shifting said filter plates towards one another; (d) a first deflecting roll carried by each filter plate on first side thereof; each first deflecting roll having a roll axis; roll axes of consecutive first deflecting rolls, as viewed parallel to said length, lying alternatingly in a first plane and in a second plane spaced from one another; (e) a second deflecting roll carried by each filter plate on a second side thereof; (f) a filter cloth supported by said first and second deflecting rolls; said filter cloth being trained in succession alternatingly about said first and second deflecting rolls for guiding said filter cloth in a zigzag course between consecutive filter plates; (g) a first sprocket affixed to each said first deflecting roll coaxially therewith for rotation with the first deflecting roll as a rigid unit; each said first sprocket having a diameter; (h) a second sprocket mounted on each said first deflecting roll coaxially therewith for free idling rotation relative to the first deflecting roll; each said second sprocket having a diameter; the distance between said first and second planes being greater than the diameter of said first and second sprockets; (i) a first elongated drive means being trained in a zigzag course in an alternating sequence about first and second sprockets of first deflecting rolls belonging to consecutive filter plates as viewed along said length; said first elongated drive means being in meshing relationship with the first and second sprockets about which said first elongated drive means is trained; (j) a second elongated drive means being spaced from said first elongated drive means in a direction perpendicular to said length; said second elongated drive means being trained in a zigzag course in an alternating sequence about second and first sprockets of first deflecting rolls belonging to consecutive filter plates as viewed along said length; said second elongated drive means being in meshing relationship with the first and second sprockets about which said second elongated drive means is trained; the zigzag course of said first elongated drive means being parallel to the zigzag course of said second elongated drive means; the diameter of said first and second sprockets and the distance between said first and second planes being dimensioned for varying the magnitude of a looping angle represented by an arc along which the first and second elongated drive means are in engagement with respective first and second sprockets to compensate for length variations of said first and second elongated drive means upon shifting motion of said filter plates relative to one another; and (k) means for driving said first elongated drive means in a first direction and said second elongated drive means in a second, opposite direction for rotating said first deflecting rolls to advance said filter cloth in said zigzag course thereof.