# US 2019/0170197 A1 · Synchronizer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170197 A1 - Document ID: US20190170197A1 - Status: Published application - Kind: A1 - Application number: 15/749,446 - Filed: 2016-08-01 - Published: 2019-06-06 - Earliest claimed: 2015-08-03 - Assignees: Piaggio & C. S.P.A. - Applicants: Piaggio & C. S.p.A - Inventors: Luca Nuti; Walter Mariotti - Web page: https://patentgrep.com/patent/US20190170197A1 ## CPC - F16D 13/18: shaped as linked or separately-pivoted segments - F16D 23/12: Mechanical clutch-actuating mechanisms arranged outside the clutch as such (specific for combined clutches F16D21/00; mechanisms specific for synchronisation F16D23/02) - F16D 28/00: Electrically-actuated clutches (arrangements for synchronisation F16D23/02; clutches actuated directly by means of an electromagnet F16D27/00; automatic clutches F16D43/00 - F16D45/00; external control F16D48/00) - F16H 19/04: comprising a rack - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - F16H: GEARING ## Abstract A synchronizer (20) for a speed transmission which can be used aboard a vehicle, in particular a motorcycle, allows the possibility of selecting each gear in any moment, by guaranteeing as additional feature that of being able to exploit the effect of the exhaust brake independently from the engaged gear and independently from the motor regime, and it comprises: a primary shaft (8); a bell-shaped member (1) assembled on said primary shaft (8) having inside a friction cylindrical surface (18); a supporting element (2), revolvingly mounted on said primary shaft (8) and housed within said bell-shaped member (1); at least a shoe (3) having a friction profile localised within the outer edge of the supporting element (2) and faced towards the friction cylindrical surface (18) of the bell-shaped member (1), jointed to said supporting element (2) by a pair of arms (4) in an articulated quadrilateral configuration; and means for translating said shoe (3) by rotating said arms (4) both in clockwise and counterclockwise direction, by causing the projection of the shoe (3) above the outer edge of the supporting element, (2) the interference of an end of the shoe (3) with said friction cylindrical surface (18) of the bell-shaped member (1), by causing a jamming thereof. ## Claims ### Claim 1 A synchronizer (20) for a transmission to be used aboard a motor vehicle, the synchronizer (20) comprising: a primary shaft (8); a bell-shaped member (1) assembled on said primary shaft (8) having inside a friction cylindrical surface (18); a supporting element (2), revolvingly mounted on said primary shaft (8) and housed within said bell-shaped member (1); at least a shoe (3) having a friction profile located within an outer edge of the supporting element (2) and faced towards the friction cylindrical surface (18) of the bell-shaped member (1), jointed to said supporting element (2) by a pair of arms (4) in an articulated quadrilateral linkage configuration; and means for translating said shoe (3) by rotating said arms (4) both in clockwise and counter clockwise direction, by causing a projection of the shoe (3) above an outer edge of the supporting element (2), interference of an end of the shoe (3) with said friction cylindrical surface (18) of the bell-shaped member (1), thereby causing a jamming thereof. ### Claim 2 (depends on 1) The synchronizer (20) according to claim 1, wherein the supporting element (2) is assembled on the primary shaft (8) by a roller bearing (7). ### Claim 3 (depends on 1) The synchronizer (20) according to claim 1, wherein on the supporting element (2) a first rack (6) is provided, and on a face of the shoe (3) opposite to the friction surface thereof a second rack (19) is formed, a pinion (5) being engaged therebetween, the jointed arms (4) being hinged to respective ends of the first rack (6) and to the ends of the shoe (3) so as to form a spaced apart and substantially radial arrangement. ### Claim 4 (depends on 1) The synchronizer (20) according to claim 1, wherein on the supporting element (2) a crown gear (6′) is provided, on a face of the shoe (3) opposite to the friction surface thereof a rack (19) is formed, a pinion (5) being engaged therebetween, the jointed arms (4) being hinged to the supporting element (2) and to the ends of the shoe (3) so as to form a spaced apart and substantially radial arrangement. ### Claim 5 (depends on 3) The synchronizer (20) according to claim 3, wherein the jointed arms (4) have a greater tilting than the radius passing through the joint thereof next to a rotation axis, the value of said tilting being comprised between 0° and 20°. ### Claim 6 (depends on 3) The synchronizer (20) according to claim 3, wherein said means for translating comprises said pinion (5) controlled in rotation with respect to the shoe (3) and to the primary shaft (8). ### Claim 7 (depends on 1) The synchronizer (20) according to claim 1, further comprising a carter (21) coupled to the bell-shaped member (1) having a plurality of permanent magnets (9) disposed thereon, positioned radially with respect to a driving axle, and electrical windings (10). ### Claim 8 (depends on 1) The synchronizer (20) according to claim 1, further comprising an electric motor (12) of the stepping type assembled coaxially to the primary shaft (8) and rotating therewith, having a stator (13) and a rotor (14) faced one onto the other one, the rotor (14) being connected to the means for translating said shoe (3). ### Claim 9 (depends on 8) The synchronizer (20) according to claim 8, wherein the electric motor (12) includes a printed circuit board (11) wherein an AC/DC converter and a remotely-controlled activating system are implemented, said system configured to control rotation of the rotor (14) of the electric motor (12) in response to a signal. ### Claim 10 (depends on 4) The synchronizer (20) according to claim 4, wherein the jointed arms (4) have a greater tilting than the radius passing through the joint thereof next to a rotation axis, the value of said tilting being comprised between 0° and 20°. ### Claim 11 (depends on 4) The synchronizer (20) according to claim 4, wherein said means for translating comprises said pinion (5) controlled in rotation with respect to the shoe (3) and to the primary shaft (8).