US 3,945,265 AGranted

Fluid actuated gear changing system

OwnerCharles Gilbert Bell, Michael M. Randolphinventors

Life of this patent

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Abstract

A gear changing system is disclosed for changing the gears in one or more automotive or truck transmissions of the mechanical type. Each rail or equivalent linkage for supporting and moving the gear changing fork is connected to the operating shaft of a fluid actuated cylinder assembly which has fluid ports connected to a plurality of control valves. The valves are connected, on one side, to a source of fluid under pressure, preferably pneumatic, and on the other side are vented to a reservoir or the atmosphere. An electrical or electropneumatic control system controls the operation of the valves, the control system including a push button selector which chooses a shift gear ratio to be attained. The push button assembly first operates a "neutral" valve which causes the cylinder means to move each shift rail to neutral. A system of microswitches detects the neutral condition and, along with a clutch switch, completes a circuit which permits fluid under pressure to be delivered to a port selected by the push button and its associated valve to move one or more cylinders and their associated gear changing rails. The disclosure also contemplates providing a gear changing mechanism such as above described in a conversion kit form for the modification of existing mechanical gear changing devices.

Claims9

Dependent claims

A system for changing the gear ratio of a transmission of a type having a plurality of gears which are movable into and out of positions of meshing engagement with other gears to establish a neutral or drive train condition in the transmission, a clutch, movable fork means for repositioning the movable gears, and a linkage for supporting and moving the fork means, the system comprising the combination of

a source of fluid under pressure;
a plurality of fluid operated cylinder means, each having an output shaft coupled to said linkage, for positioning the linkage,
said cylinder means each having three ports for passing fluid under pressure and being responsive to the application of fluid under pressure at a first one of said ports to move said shaft to a central position, a second one of said ports to move said shaft to a position displaced in one direction from said central position, and a third one of said ports to move said shaft to a position displaced in the opposite direction from said central position;
a control valve unit having a plurality of valve means for selectively directing fluid under pressure from said source to ports of said cylinder means,
said plurality of valve means including a first valve means for simultaneously applying fluid under pressure to said first port of all of said cylinder means and the remaining ones of said plurality of valve means being operable for individually applying fluid under pressure to selected ones of said second and third ports;
and
shift selection means for sequentially actuating said first valve of said control valve means and then a selected one of the remaining ones of said valve means to cause a selected one of said cylinder means to move its output shaft and the linkage coupled thereto to a new shift position.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/522,214Filed 8 Nov 1974
Granted: 23 Mar 1976
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

F16H 61/30
With at least one movement of the final actuating mechanism being caused by a non-mechanical force, e.g. power-assisted: hydraulic or pneumatic…
F16H 63/44
Comprising signals other than signals for actuating the final output mechanisms: signals to the control unit of auxiliary gearing
F16H 2061/307
Hydraulic or pneumatic motors or related fluid control means therefor: actuators with three or more defined positions, e.g. three position servos
Y10T 74/19167
Gearing: in series plural interchangeably locked nonplanetary units