Abstract: A linear actuator includes a housing, a spindle rotatable in both directions, a threaded nut driving a piston rod, and a motor capable of driving the spindle through a transmission, a disengagement unit being arranged in the transmission for interrupting the connection between the motor and the spindle in case of operational failure, such as overloading of the spindle, the disengagement unit comprising brake means adjustable with respect to the actuator housing to cooperate with coupling means for control of the rotational speed of the spindle when this is disengaged from the motor. The linear actuator provides an emergency function ensuring that the linear actuator and the carried load are not damaged by overloading of the actuator.

Abstract: A three-way or multi-way valve is provided, which is built up of a plurality of two-way valves, each of which has a high pressure connection and a low pressure connection which are separated from each other by means of a valve seat with which a closure element co-operates, the two-way valves being arranged to be operated in pairs or in groups by means of a control pressure fluid by way of a control pressure line opening into a pressure chamber, and one of the two-way valves of each group being arranged in a connection between a pressure source and a load, and another two-way valve of the same groups being arranged in a connection between the load and a pressure sink. With a valve of this type, it is desired to obtain improved closing behavior with simple construction. For this purpose, at least one of the connections, especially the high pressure connection, of at least one valve of each group communicates with the control pressure line by way of a throttle channel.

Abstract: A two-way seat-type valve is provided, having a valve seat which is arranged between a first and a second connection, and having a closure element which co-operates with the valve seat, is arranged in a guide so as to be movable towards the valve seat or away from the valve seat, and which is subjected to a control pressure prevailing in a pressure chamber on the side, remote from the valve seat, of the closure element. A valve of this type should also be able to exhibit good reaction characteristics with water as hydraulic fluid. For this purpose, the closure element is guided seallessly in the guide.

Abstract: Motorised head pulley comprising a rotating drum, which is driven by a permanently mounted hydraulic motor situated in the pulley. Between the motor and the pulley, a reduction gear is inserted. The motor and the reduction gear comprise moving parts, which are designed for operation in contact with a water-based, lubricant-free pressure fluid. The motorised head pulley can by this be used without having to pay attention to the risk of pollution from the hydraulic medium. The motorised head pulley is especially appropriate to drive conveyors in food processing production.