They consist of a trio of bevel gears with a 1/1 and 1/2 transmission ratio (only in reduction).
reverse the direction of rotation of the through shaft while maintaining the direction of rotation of the input shaft by providing a “neutral” function in the intermediate position.

The manoeuvre is performed manually by acting on the control lever, with the machine at a standstill.

The engagement position is usually indifferent, and in this case the gearbox is called FP (Full Position). On request, they are manufactured with an obligatory, single engagement position, and these are called SP (Single Position).

They are manufactured in sizes 32 – 42 – 55.