Abstract: An auxiliary mechanical position locking device is coupled to the hydraulic system that motivates a double acting piston for positional control of surgical tables. The combination of hydraulic coupling and mechanical locking maintains positional stability of the surgical table and insures against sudden or precipitous movements.

Abstract: Electromagnetically actuable hydraulic control valve with a valve housing in which a series of valve bodies are disposed in control bores for longitudinal displacement between at least two shift positions, and with a pot electromagnet disposed on the valve housing. The valve has an armature in the form of a large-area, substantially flat plate provided between the pot electromagnet and the valve housing, to which armature at least a part of the valve body ends protruding from the valve housing are attached. The armature plate is provided on its flat side confronting the valve housing with a guide shaft protruding at right angles and guided in a slidingly displaceable manner in a bore in the valve housing.

Abstract: A mechanical actuating device for hydraulic control valves having complex control functions, which can be assembled from individual units in a modular system, each of which has valve bodies which can be operated by longitudinal displacement in a housing that can be joined to the housing of the adjacent module. The actuating device for each module has a cam control member rotatably mounted in a cam housing which can be placed on the module housing and which can be brought into engagement with the ends of the valve bodies protruding from the module housing. The cam control members of all individual modules are disposed with aligned axes of rotation, and a coupling is provided for the co-rotational joining together of the cam control members of adjacent modules in selectable relative angular positions to one another.