An arrangement for a connection device for providing detachable connection of pairs of elements through a displaceable piston capable of actuation by spring force. The spring is accommodated internally within a cavity in a connection sleeve with a retaining end of the piston and is capable of being locked in a connection position by a locking screw that interacts with an inclined tensioning surface in the piston and with a gripping device projecting from the cavity on a connecting end of the piston. The gripping device faces outward from the cavity. A lock is present between the sleeve and the piston to limit the projection of the piston from the internal cavity of the sleeve.