Abstract: Liquid is circulated from bottom to top in a pressure tank by means of a gas pump including an upstanding pipe located within the tank and up through which gas is pumped at a pressure exceeding tank pressure to carry liquid which enters the pipe at the bottom up to the top of the tank.

Abstract: Cake control members are mounted at the peripheries of filter leaves and filter tubes to confine the build-up of filter cakes and prevent the cakes from extending over the peripheries of the elements.

Abstract: The exhaust manifold in a pressure filter is spring mounted and vibrated along a vertical axis to dislodge filter cakes from filter tubes suspended from the manifold.

Abstract: A filter element utilizes a perforate inner filter tube sock tightly fitted within an outer perforate support tube sock, the two socks being sealably mounted at their open ends to a tube sheet with the support tube held in tension by the pressure differential across the filter tube during operation of the associated filter.

Abstract: A hydraulic actuator for transversely shifting the relative positions of a needle bar and the backing material in a tufting machine. An electronic pattern control mechanism drives the hydraulic actuator in response to the predetermined stitch pattern information in the electronic control circuit, which determines the amount of relative transverse shifting of the needle bar for each stitch location. A feedback mechanism associated with the hydraulic actuator creates a feedback signal which is compared with a pattern stitch command signal in order to produce an output signal for shifting the hydraulic actuator to a subsequent transverse needle bar position relative to the preceding needle bar position.

Abstract: An axially rigid, tubular grid is fitted over an apertured conduit; a fine mesh flexible tube is fitted over the grid with the ends of the tube being folded back over annular sealing gaskets disposed at the ends of the grid; and an end cap is threaded onto the distal end of the conduit to compress the gaskets against the conduit at the ends of the grid to seal the ends of the flexible tube to the conduit.

Abstract: The moisture content of filter cake removed from filter leaves is reduced by sluicing off peripheral portions of the cakes while the central portions of the cakes are held under compression against the filter leaves, and thereafter removing the remainder of the cakes in a dry discharge operation.