Patent ID: 7883512

Claim:
An apparatus for application of bone cement comprising: a housing having a cylinder for receiving the bone cement and having a piston arranged in a longitudinally displaceable manner in the cylinder by which the bone cement can be pressed out through an exit aperture formed in the cylinder; a screw movement for longitudinally displacing the piston in the cylinder for the application of the bone cement under high pressure; and an arrangement for switching between the displacement of the piston by the screw movement and a direct displacement in the longitudinal direction without a screw movement, the arrangement including a biasing spring and a cooperating toothed arrangement, wherein said screw movement comprises an engaging thread section having a screw thread, the biasing spring resiliently pushing the cooperating toothed arrangement in a linear direction perpendicular to the longitudinal movement of the piston into releasable engagement with the engaging thread section such that the longitudinal displacement of the piston is effected when the engaging thread section is turned, and engagement of the engaging thread section and cooperating toothed arrangement being resiliently released when biasing of the spring is released to lineally move the cooperating toothed arrangement away from the engaging thread section in a direction perpendicular to the longitudinal movement of the piston and without a movement of the cooperating toothed arrangement in the direction of the longitudinal movement of the piston.