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.
1. A single use device for mixing and applying a paste such as bone cement, including a cylinder receiving the paste, a piston reciprocable in the cylinder, a piston rod displaceable and rotatable in the piston and forming mixing means for paste received in the cylinder, and latch means for interconnecting the piston and the piston rod to allow displacement of the piston in the cylinder by means of the piston rod for deposition of the paste outside the cylinder, wherein jamming means are provided for locking the piston rod to the piston, said jamming means allowing the piston rod to be locked to the piston at any position along the complete length of the piston rod.
2. The single use device according to claim 1 , wherein the piston is divided into front and back components rotatable relative one another.
3. The single use device according to claim 1 , wherein the cylinder is gas tight, which enables mixing of the paste under vacuum.
4. The single use device according to claim 1 , wherein the jamming means in the piston include a lock member with a central hole receiving the piston rod, which member in the jamming position is supported in a position laterally displaced relative to the centre axis of the piston rod.
5. The single use device according to claim 1 , wherein an external ring on the cylinder is rotatable for locking of the piston to the piston rod.
6. The single use device according to claim 5 , wherein the external ring is secured by securing means, to prevent the ring from being turned accidentally.
7. The single use device according to claim 5 , wherein the piston rod is restricted from being pulled backwards by an elastic body provided behind the piston.
8. The single use device according to claim 1 , wherein the piston is provided with sealing means to ensure the gastightness of the cylinder.
9. The single use device according to claim 1 , wherein single use is guaranteed by the jamming means which irreversibly locks the piston to the piston rod.