Abstract: A silenced sprocket comprises, adjacent to the base of its teeth, a circular channel, or bilateral channel, on the metal body of the sprocket itself. The bilateral channel has a minimal radial extension, a silencing rubber element (106?), and a bilateral channel. The bilateral channel creates its own housing and has a minimal radial extension compared to the sprocket radius. The silenced sprocket is made by a molding technique that uses special molding components, adapted to apply the rubber silencing element on the sprocket metal body. These components are of annular circular shape, U cross section and a width essentially corresponding to the channel width, rendering the mold independent from the specific shape of the sprocket metal body.

Abstract: Single-acting cylinder-piston unit of plunger type, having a cylinder (1) closed at one end and containing a slidable cylindrical rod (5), the inner end of which presents two adjacent circumferential grooves (18, 28), the first (18) of which acts as a final seat for a split ring (8) defining the limit of the outward stroke of the rod and the second (28) of which acts as a temporary seat for the split ring, enabling the rod with the split ring mounted thereon to be inserted into the cylinder, the second groove (28) being at the inner end of the rod and the first groove (18) being more towards the opposite end of the rod, in proximity to the base, a counteracting member being arranged to interfere with the split ring to cause it to transfer from the second groove to the first groove during the final stage of insertion.

Abstract: Hydrostatic power steering device comprising a source of pressurized fluid, a cylindrical barrel-type distributor the elements of which are connected elastically together, and of which the inner element, the so called spindle, is connected to the steering wheel; the distributor being arranged to assume a central position, the so-called neutral position, in which it directly short-circuits, to discharge, the fluid originating from the source of pressurized fluid, and two positions, symmetrical about the central position, in which the distributor, via a dispenser of orbital type the rotor of which is rigidly connected to the steering wheel shaft and to the spindle, feeds the fluid to one and respectively to the other of the chambers of a hydraulic actuator connected to the steering wheel; the device also comprises an auxiliary conduit for feeding the pressurized fluid to the cylindrical distributor; a slide valve operable by the driver to feed said auxiliary feed conduit when desired; a barrel locking system op