Abstract: A filter arrangement is suggested where the filter means (38) is placed between distance pieces (48, 50, 52). In order that the longitudinal edges (64, 66, 68) of the preferably zigzag-folded distance pieces cannot cause any damage to the filter means, they are provided with a substantially edgeless cap (90, 92, 94), of which the maximum width equals that of the distance pieces.

Abstract: A linear drive unit is proposed of a device (10) for cleaning of filtered fluids in particular, whereby the compressed air required for cleaning is emitted via a nozzle bar (21, 23). The nozzle bar (21, 23) extends from a cylinder (18) suppliable with compressed air and being movable along a piston rod passing (16) through the faces of the cylinder, said piston rod being enclosed by a partition wall (26) arranged stationary and dividing the cylinder interior into two chambers (28, 30). To supply the chambers (28, 30) with compressed air, the piston rod (16) is designed hollow in sections for the fluid to flow through, with each chamber being associated with a hollow section (32, 34) of the piston rod and having connections (42, 44) leading to it.