Abstract: A continously-variable-ratio transmission ("CVT"), for instance of the toroidal-race rolling-traction type, capable of geared neutral and of operating in at least two regimes and including a ratio-varying component ("variator"), a power-recircuiting epicyclic, a final drive shaft connectable with the variator by way of one of two alternative driven shafts and an input epicyclic the input of which is connectable to a prime mover and the two outputs of which are connected to the two alternative driven shafts respectively. One of the regimes includes a "geared neutral" condition, and the power-recirculating epicyclic is associated with clutches whereby power is recirculated through it in that regime. In the remaining one or more regimes no power is recirculated within that epicylic, but drive reaches the CVT output by way of appropriate clutches and whichever of the two driven shafts will rise in speed as that regime proceeds.

Abstract: A continuously-variable-ratio transmission (CVT) of the toroidal-race rolling-traction type, capable of operating in "low" and "high" regimes with synchronous change between those regimes, and including a variator (3)--that is to say a ratio-varying component--and an associated gearing set (2) of which the components are capable of being set in different combinations for the high and low regimes, in which the output of the gearing is connectable to the output (1) of the CVT as a whole, and the gearing has first (25) and second (29) inputs connected with the variator output (19) and engine output (5) respectively, and in which in low regime the gearing is set to recirculate power and so deliver to its output a power equal to the difference between its two input powers, whereas in high regime it is set to as to split the power flow and to deliver to its output a power representing the sum of the powers at its two inputs.

Abstract: A roller control system for a CVT of the toroidal-race, rolling-traction type in which a roller assembly comprises a roller (1) mounted in a carriage, and in which operating mechanism (10) contacts and applies a predetermined control force to the carriage whereby to control the manner in which its roller transmits torque and ratio between the two dics with which it is in contact, and in which the roller assembly is located by only three contacts with adjacent components namely the two disc/roller contacts and the contact with the operating mechanism. The roller centre (6) can move along the roller axis (5) relative to the carriage, and the carriage and the operating mechanism are connected by way of a hinged joint (7) with a single degree of freedom. The preferred operating mechanism is of piston (11, 12) and cylinder (13, 14) type. The axis (8) of the hinge may lie between the operating mechanism and the roller, or (e.g. at 40, FIG. 4) may pass through the operating mechanism itself.

Abstract: A continuously variable transmission with coaxial input (from 6) and output (17), capable of operating in at least two regimes, and having a variator (2) of the toroidal-race rolling-traction type, and gearing including both a speed reducing unit (10) and an epicyclic mixing gear unit (15) in which the components of the mixing gear unit are locked up in at least one of the regimes, and in which the speed-reducing unit (10) effects its speed-reduction without reversal of the direction of rotation between its input (1) and output (from 26). The operating axis (5) of the variator (2) may either coincide with the coaxial input and output of the transmission (FIG. 2 ) or be parallel to but displaced from it (FIG. 3 ). In addition to a brake (13) and a clutch (20), operable to engage first and second regimes, a further clutch (48) operable to engage a third regime is shown.

Abstract: A roller control system for a continuously-variable-ratio transmission of the toroidal race, rolling traction type, in which rollers (60) of variable orientation transmit traction between a part-toroidal race (85) formed on an input disc (61) and a similar race (87) formed on a coaxial output disc (62). Each roller is mounted to rotate about a fixed centre (66) and a fixed axis (58) within a rigid carriage (67), one end of which contacts operating mechanism reciprocable over a predetermined stroke of operating movement and operable to apply a control force to the carriage. The assembly of roller and carriage is located by only three contacts with adjacent structure, namely the two disc/roller contacts (86, 88) and the contact (82) with the operating mechanism.

Abstract: A ratio-varying component for a transmission of the toroidal-race rolling-traction type, in which each of the rollers (1) transmitting torque between an input disc (51, FIG. 3) and a corresponding output disc (40) is positioned hydraulically by means of an attached hydraulic piston (5) and cylinder (6) combination, in which all the cylinders lie to the same side of a common plane (43a) including the axis (43) of the discs. The cylinders may be supported on a common block-like structure (41), in which hydraulic conduits (31a, 32a, 37a, 44) may be contained.

Abstract: A rotatable disc (1, 3) formed with a coaxial part-toroidal race (26, 27) for use as the input or output disc of the variator for a transmission--especially of the full toroidal kind--of the toroidal-race rolling-traction type, in which the torus radius (r.sub.d) of the race, that is to say the radius of curvature of the race measured at a chose point on the race and in a plane including the disc axis, decreases as the distance of that point from the disc axis (5) diminishes. Such decrease of the torus radius may be either continuous or discontinuous.

Abstract: A two-regime, continuously-variable-ratio transmission of the toroidal-race rolling-traction type in which the variator (2) reducing epicyclic (10) and mixing epicyclic (15) are all coaxial, in which the driving connection between the variator output and the sun gear (18) of the mixing epicyclic includes a layshaft (23) or the like lying radially outboard of the reducing epicyclic, and avoids the use of a drum-like component which would surround those parts of the variator lying downstream of its output member (8). The invention also facilitates the use of gear units of equal ratio, and indeed of substantially identical structure, for the reversing (10) and mixing (15) epicyclics.

Abstract: A driveline for a wheeled vehicle in which two laterally-displaced driving wheels (37, 38) are driven by the output (33, 36) of a transmission of continuously-variable ratio. The transmission is capable of a "geared neutral" condition, and is driven by way of a slipless connection (5, 6, 7; 70-73) from the engine (2). The engine output axis (3), the engine/transmission connection and the variator output axis (15) are arranged in a "U"-shaped formation. Such an arrangement promotes a compact and well-balanced installation in which the vehicle centerline (1) may roughly bisect the engine, and the wheel half-shafts (43, 44) can be nearly equal in length. Alternative embodiments are described in which the output axis of the variator coincides with the final drive axis (FIG. 3), or is parallel to but displaced from it (FIG. 1).

Abstract: A transmission system for use in automobile vehicles and in which the ratio-varying unit is unidirectional and is of the continuously-variable type, particularly the toroidal-race rolling traction type. An epicyclic combination and a hydrokinetic element are located in succession between the output of the ratio-varying unit and the final drive output of the system as a whole. The epicyclic combination and hydrokinetic element help to overcome two typical problems of transmissions with such ratio-varying units, namely low output torque range and difficulty in starting from rest, and this arrangement and the torque-splitting action of the epicyclic combination enable a smaller element to be used than would be possible if it were located on the input side of the ratio-varying unit. The system also includes a reversing mechanism located downstream of the ratio unit and preferably between the hydrokinetic element and the final drive output.

Abstract: A rotary transmission of continuously-variable-ratio type including a variator, that is to say a ratio-varying unit, and a subsequent gearing unit, the gearing unit being capable of alternative settings whereby the transmission may operate in two different regimes. The axes of rotary operation of the variator and the gearing unit are displaced from but parallel to each other, and the entire gearing unit lies between the two radial planes marking the axial extremities of the variator, which may be of the toroidal-race rolling traction type with two input discs located at opposite axially ends and a single, double-faced output member located centally between them, that member coinciding axially with the member of the gearing unit to which it is connected. The means of connection may be direct geared engagement, involving reversal of direction of rotation, or connection by chain, belt or the like involving no such reversal.

Abstract: A transmission system, especially for use in automobile vehicles, in which the ratio-varying unit is of the continuously-variable type particularly the toroidal-race rolling traction type. An epicyclic combination is located between the ratio-varying unit output and the final output of the system as a whole. In reverse drive a band brake is engaged to arrest the epicyclic planet carrier so that the unit output and final output are connected by way of the epicyclic gearing, and an epicyclic ratio of substantially greater than 1:1 promotes proper speed limitation in reverse drive. In forward drive the brake is disengaged but a friction clutch is engaged to connect the unit output directly to the final output. By their progressive action the brake and clutch enable the transmission to start from rest in either forward or reverse drive, without the need for separate friction clutches.