US Patent 7513679 Device for mixing and delivering bone cement

Device for mixing and applying a paste such as bone cement or the like, including a cylinder 3 receiving the paste, a piston 1 reciprocable in the cylinder 3, a piston rod 2 displaceable and rotatable in the piston 1 and forming mixing means 21 for paste received in the cylinder 3, and latch means for interconnecting the piston 1 and the piston rod 2 to allow displacement of the piston 1 in the cylinder 3 by means of the piston rod 2 for deposition of the paste outside the cylinder 2, characterized in that means are provided for locking the piston rod 2 to the piston 1 by jamming, said means allowing the piston rod 2 to be locked to the piston 1 at any position along the complete length of the piston rod 2.