Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
166 words
A variable ratio frictional drive gear comprising two axially spaced torus discs having respective mutually presented toroidal surfaces, a set of circumferentially spaced drive rollers in frictional contact with the toroidal surfaces of the discs, roller carriages in which the rollers are respectively rotatably mounted about axes at right angles to the roller axes, to vary the distance from an axis of the drive gear at which the rollers engage the discs, a first piston arranged, under the influence of hydraulic fluid supplied thereto, to control tilting movement of at least one of the roller carriages, a second hollow piston in which the first piston is slidable, pressure reducing means operable when said first piston reaches a predetermined position in relation to said second piston, a cylinder in which the second piston is slidable, a governor for supplying fluid to said cylinder, and means independent of the hydraulic fluid supplied to said first piston, for supplying control fluid to said governor and thence to said cylinder.
Claim 2
Dependent Claim
166 words
A variable ratio frictional drive gear comprising two axially spaced torus discs having respective mutually presented toroidal surfaces, a set of circumferentially spaced drive rollers in frictional contact with the toroidal surfaces of the discs, roller carriages in which the rollers are respectively rotatably mounted about axes at right angles to the roller axes, to vary the distance from an axis of the drive gear at which the rollers engage the discs, a first piston arranged, under the influence of hydraulic fluid supplied thereto, to control tilting movement of at least one of the roller carriages, a second hollow piston in which the first piston is slidable, pressure reducing means operable when said first piston reaches a predetermined position in relation to said second piston, a cylinder in which the second piston is slidable, a governor for supplying fluid to said cylinder, and means independent of the hydraulic fluid supplied to said first piston, for supplying control fluid to said governor and thence to said cylinder.
Claim 3
Dependent Claim
43 words
A variable ratio frictional drive gear as claimed in claim 1 wherein said second hollow piston is in the form of a sleeve, a radially outwardly extending flange at the inner end of said sleeve being slidably engaged the wall of said cylinder.
Claim 4
Dependent Claim
90 words
A variable ratio frictional drive gear as claimed in claim 1 wherein an annular passageway defined by an annular circumferential groove in the first piston and said second piston provides a source of hydraulic fluid, said passageway being connected to one axial end of said first piston, said pressure reducing means comprising a recess formed in sAid second piston communicating with said annular circumferential groove when said first piston reaches said predetermined axial position in relation to said second piston to allow hydraulic fluid to escape from said annular passageway.
Claim 5
Dependent Claim
84 words
A variable ratio frictional drive gear as claimed in claim 2 wherein a pair of chambers are defined between opposed ends of said radially outwardly extending flange and said housing and one of said chambers which is partly defined by the innermost axial end of the flange is arranged to be supplied with control fluid from the governor and the other of said chambers is arranged to be supplied with hydraulic fluid to urge the second piston against force exerted by said control fluid.
Claim 6
Dependent Claim
23 words
A variable ratio frictional drive gear as claimed in claim 1 wherein said first piston is connected to one of said roller carriages.