The base piece (2) and the cover piece (3) are connected by an externally hinged rocker (4) that is located therebetween, and the expansion device is an expansion clamp (6, 6') on the rocker, a pushing device (5) being provided for the expansion clamp.

The expansion clamp allows the rocker to be raised so that the implant expands vertically.

Furthermore, the frictional forces of the expansion clamp prevent an unwanted return movement.

At least one lateral outlet opening for releasing a support element of a door leaf is arranged in the rail profile at a distance from the expanding clamp.

The base piece (2) and the cover piece (3) are connected by an externally hinged rocker (4) that is located therebetween, and the expansion device is an expansion clamp (6, 6') on the rocker, a pushing device (5) being provided for the expansion clamp.

The expansion clamp allows the rocker to be raised so that the implant expands vertically.

Furthermore, the frictional forces of the expansion clamp prevent an unwanted return movement.

Disclosed is a clamp (210) that includes a bolt (214), a spacer (218), a shank (116), an expander (112) and a blocking means (128).

The two plier arms (4, 5) can be fixed in different clamping positions which vary with the distance between the two clamping sections (7, 9).

At least one lateral outlet opening for releasing a support element of a door leaf is arranged in the rail profile at a distance from the expanding clamp.

The spacer comprises at least a first spacer portion and a second spacer portion formed on top of the first spacer portion.

The spacer block can be a two-part spacer block.

The blade assembly includes a first blade assembly and a second blade assembly.

There are also two side bars used for displacing thrust frames.

One end of each side bar is fixed to the mobile traverse and the other is fixed to a holder with the aid of a screw clamp.