PULLEY WITH IMPROVED PIN TO SUPPORT WIRES FOR MULTI-WIRE CUTTING MACHINE OF STONE BLOCKS

Pulley (1 ) with an improved pin, comprising: a hub (3) within which the external ring (11) of a rolling bearing (12) is keyed; a rotary support pin housed within the internal ring (13) of said bearing; protection labyrinths housed between the pin and the hub for the protection of the bearing; a circumferential groove (6) which is circumferential to the external diameter of the pulley (1 ) in which a shaped coating (7) is housed for the contact with the diamond wire (8); the hub of the pulley being made in two parts (9, 10) which are tightened in a stable way on the internal diameter of the pulley (1); moreover, it has each external face (18) of the hub provided with an annular labyrinth (17) which penetrates each other with an annular labyrinth (16) present on each internal face of a disassemblable pin (2) made in two parts (14, 15) and axially tightened by a releasable connecting member (19); and having the connection, between the improved pin (2) and the support (20) of the pulley (1 ), realized by means of tightening members (26) and guiding members (25), inserted in a direction parallel to the laying plane of the pulley, in the thickness of the walls (29, 30) of the support. Here described are specific advantageous embodiments of construction and mounting of the parts of the pin (2), of fixing of the improved pin to the support (20) and of external configuration of the pin (2), to facilitate the interlocking between pulleys and wires in the multi-wire machine for cutting blocks of stone.