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.

Abstract: A central belt lock, particularly for a parachute harness, includes a housing, a main pin or journal which is manually rotatable and axially movable therein, and an anchor plate which cooperates with a plurality of retaining bolts for the belt attachment or coupling members. There is dealt with the problem of allowing the belt attachment members to be released and thus disconnected from the lock even if the parachutist for some reason is unable to actuate the lock manually, after making a jump over the sea. Therefore, a central belt lock is provided to be activated by sea water and can be released thereby, without affecting the function thereof when operated manually. For this purpose, the main journal (2a) has at least one longitudinal bore in which a push rod (12) is mounted so as to be longitudinally movable. An actuator (20, 27) is associated with the push rod and is actuated when coming into contact with water, axially moving the push rod (12) and hence the anchor plate (5) with the retaining bolts (6).