Patent ID: 8016510

Claim:
A joint movably connecting two stabilizing elements, the joint comprising: first and second segments that can rotate relative to each other about an axis of rotation, each joint segment connected to a respective stabilizing element extending radially outward from the axis of rotation, the respective stabilizing elements pivoting relative to one another, the first joint segment having a cavity coaxial to the axis of rotation; locking means for releasably locking the joint, the locking means comprising a piston displaceable in the cavity and parallel to the axis of rotation; a line one of supplying and discharging a fluid in communication with the locking means wherein the locking means can be locked by the fluid being supplied and unlocked by the fluid being discharged via the line; wherein: the piston can be pressed against the second joint segment by means of supplying or discharging fluid; the piston comprises a front face that stands crosswise to the axis of rotation, the front face operative to be pressed against the second joint segment; the piston also comprises a rear face that stands crosswise to the axis of rotation; the fluid can have pressure applied to it and can be supplied to the cavity delimited by the rear face of the piston via the line; and the second joint segment comprises a contact surface that stands crosswise to the axis of rotation and is directed against the first joint segment, the contact surface and the front face of the piston comprising toothed gear wheels that can be brought into engagement with one another.