Means for performing gear changes in multi-ratio gear-boxes

Claim 2

In an apparatus for automatically or semi-automatically performing rapid gear changes in a multi-ratio change-speed gear box having members which are selectively moved into engagement to effect the desired gear ratio comprising, a source of fluid under pressure, a fluid receiving sump, at least one actuating cylinder having a piston connected to one of said gear-box members to be moved in a gear change, at least one fluid actuated two-position three-way main valve of large capacity connected to each actuating cylinder and also connected to said fluid source and said fluid-receiving sump, said main valve having a large crosssectional area in each direction of operation, an electromagnetic two-position three-way primary valve actuated by electrical signals controlling the gear change operations, the primary valve having only a small cross-sectional area in each direction of operation and being in fluid communication on the one hand with means to actuate the main valve and on the other hand with the fluid source and the sump, said fluid pressure source, the sump, all of said cylinders and all of said valves being mounted on a single base which is secured as a cover to the gear box.

Claim 3

The apparatus of claim 1 wherein the fluid pressure source includes a reservoir and a pump and all connections between the reservoir, pump, actuating cylinders and valves are direct orifice to orifice connections without intermediate pipes.

Claim 4

Apparatus for automatically or semi-automatically performing gear changes in gear boxes having multi-ratio gear wheels and axially slidable pinions or toothed dogs which are to be brought into engagement to provide the different ratios, said apparatus comprising a fluid pressure source, a fluid-receiving sump and actuating cylinders, pistons in said cylinders connected to gear box components which are to be moved in performance of a ratio change, said cylinders being connected through at least one hydraulically actuated large capacity main valve to the fluid pressure source and to the sump, said main valve being controlled by an electro-magnetic primary valve of relatively small capacity, a hydraulic actuating cylinder with an electro-magnetically actuated valve arrangement for actuating a clutch at The input of the gear box and means for changing the speed of a member of the gear box to synchronize its speed with a member to be engaged thereby, said fluid pressure source, fluid-receiving sump, all actuating cylinders, valves and means for changing speed of a member of the gear box being combined together in a constructional unit adapted to be mounted on the gear box as a cover and comprising a single base on which the said source, sump, cylinders, valves and speed changing means are mounted.

Claim 5

Apparatus for automatically or semi-automatically performing gear changes in gear boxes having multi-ratio gear wheels and axially slidable pinions or toothed dogs which are to be brought into engagement to provide the different ratios, said apparatus comprising a fluid pressure source, a fluid-receiving sump and actuating cylinders, pistons in said cylinders connected to gear box components which are to be moved in performance of a ratio change, said cylinders being connected through at least one hydraulically actuated large capacity main valve to the fluid pressure source and to the sump, said main valve being controlled by an electro-magnetic primary valve of relatively small capacity, a hydraulic actuating cylinder with an electro-magnetically actuated valve arrangement for actuating a clutch at The input of the gear box and means for changing the speed of a member of the gear box to synchronize its speed with a member to be engaged thereby, said fluid pressure source, fluid-receiving sump, all actuating cylinders, valves and means for changing speed of a member of the gear box being combined together in a constructional unit adapted to be mounted on the gear box as a cover and comprising a single base on which the said source, sump, cylinders, valves and speed changing means are mounted.

Claim 6

The apparatus of claim 3 wherein an actuating cylinder with a control valve arrangement serving to engage and disengage a reverse gear is mounted on the said base.