A cylinder for mixing components to form bone cement

In a device for mixing at least first and second components of a bone cement and for discharging bone cement, the device including a two-part mixing cylinder in which an openworked mixture plunger is moved axially and rotatably by means of an actuation rod emerging in a sealed manner at one cylinder end, the mixing cylinder being closed at the other cylinder end by a releasably locked discharging plunger which is pressed axially into the mixing cylinder in order to discharge the mixed bone cement through an opposite discharge opening, the improvement comprising:

• a separating plunger (10) arranged for axial displacement in the mixing cylinder (1) between the mixing plunger (5) and the discharging plunger (12);
• the separating plunger (10), mixing plunger (5) and discharging plunger (12) being initially disconnected from one another;
• the separating plunger being a rigid, imperforable element;
• the first component of the bone cement being a pulverulent polymer (30) and the second component of the bone cement being a liquid monomer (15);
• a first cylinder chamber (11) extending from a first end of the mixing cylinder (1) and initially containing the first component 30;
• a second cylinder chamber (13) disposed between the separating plunger (10) and discharging plunger (12);
• a container (14) for the second component (15) of the bone cement being disposed in the second cylinder chamber (13);
• the cylinder chambers (11, 13) of the mixing cylinder (1), which are initially separated from each other by the separating plunger (10), being connected to each other via at least one through-flow channel (18) in at least one of said separating plunger and mixing cylinder, whereby upon displacing the mixing plunger toward the second cylinder chamber (13), the separating plunger (10) moves to rupture the container (14) and the second component (15) flows through the at least one channel (18) to mix with the first component (30).