The standard version of the device is assembled of an upper (2) and a lower segment (4), a guide bar accommodated inside, toothed contact surfaces, and a tool at the lower end. By acting on a handle (3) at the top the tool was rotated back and forth. The new design is fitted with a locking unit (15) facilitating the use of the tool for a wider range of purposes. The unit (15) comprises a sphere engaging with a groove at the guide bar and moved with a sleeve (14) located at the outer surface of the meeting area of the two handle segments (2, 4).
