Operational table for medical purposes

Claim 1

An operational table for medical purposes, having a hydraulic operating system, said operating system having a pressureproducing device comprising a pump, a foot pedal actuating said pump and a central valve actuating unit comprising a valve casing having the shape of a hollow cylinder, a dividing member located piston-like in said casing and rotatable about the axis of said casing, a tubular outwardly extending shoulder carried by said dividing member, a cylindrical flange fixed to said casing upon the side opposed to said shoulder, said dividing member and said flange having concentrical passages, an axially movable pin extending through said passages, said flange having an inwardly radially extending working surfaCe, a plurality of working cylinders having flow channels, said flow channels opening in pairs into said working surface and being uniformly divided over its circumference, said dividing member also having a radial working surface extending toward the first-mentioned working surface and sealed relatively thereto, means forming the other flow channels opening into the second-mentioned working surfaces, the openings of said other flow channels being alined with a pair of the first-mentioned flow channels, one of said other flow channels having a channel extension opening into one of said passages, the other one of said other flow channels having a fork-like extension with two side channels, said side channels extending at equal distances from and on opposite sides of said channel extension and opening into one of said passages, said pin having two grooves surrounding the pin and spaced at a distance corresponding to two openings, said pin also having two axial channels communicating with said grooves and extending to an outwardly projecting part of said pin, pressure means connection for the supply and withdrawal of pressure means, said axial channels being connected with said pressure means connection, an axially swingable lever mounted upon the tubular shoulder of the dividing member, said lever swinging said dividing member relatively to said casing about a common axis of symmetry, and means pivotally connecting said lever with said pin and transmitting the axial movement of said lever to make the axial movement of said pin equal to the distance between the two axial channels of the pin, whereby, in the two end positions of said lever, the pressure means connection is crosswise connected with said other flow channels.