Pneumatic shift control for a mechanical transmission

Claim 2

In combination with a transmission having a change speed gear section (22) with a plurality of fluid operated actuators (37, 38, 39, 41) therein for establishing a plurality of different speed ratios therethrough, a shift control system comprising: a source of pressurized fluid (89); a plurality of power valves (78 to 81); an actuator control valve (92) connected between said pressurized fluid source and said power valves and providing a flow path to each of said actuators through a separate one of said power valves; a manual control (66) movable between a plurality of positions each corresponding to a separate one of said speed ratios, said manual control being movable in an additional direction at each of said positions; means (72 to 75) responsive to said movement of said control between said positions to operate a unique combination of said power valves at each of said positions; and means (96) responsive to said additional movement of said control at any of said positions to operate said actuator control valve whereby said power valves are conditioned to shift a unique combination of said actuators by movement of said control to any of said positions and actual shifting of said actuators occurs only after said additional movement of said control at any of said positions.

Claim 3

The combination defined in claim 1 wherein said power valves each have a pilot inlet and are operated by changing the fluid pressure thereat, and wherein said means responsive to movement of said control between said positions thereof comprises a plurality of pilot valves (72 to 75) each being connected to said source of pressurized fluid and to the pilot inlet of a separate one of said power valves and each having a mechanical actuating element (136) positioned for operation by movement of said control to predetermined ones of said positions thereof.

Claim 4

The combination defined in claim 1 wherein said means responsive to said additional movement of said control is actuated by fluid pressure signals and further comprising a shift valve (69) connected between said source of pressurized fluid and said means responsive to said additional movement, said shift valve having a mechanical actuating element (173) positioned for operation by said additional movement of said control.

Claim 5

The combination defined in claim 1 wherein said actuator control valve has two position positions one of which communicates said flow paths with said source of pressurized fluid and the other of which vents said flow paths, and wherein said means responsive to said additional movement of said control shifts said actuator control valve from a first to a second of said positions in response to said additional movement of said control and shifts said actuator control valve back to said first position in response to opposite movement of said control.

Claim 6

The combination defined in claim 4 wherein said means responsive to said additional movement of said control includes a timer (108) delaying said shifting of said actuator control valve from said first to said second position after said additional movement of said control.

Claim 7

The combination defined in claim 1 wherein said manual control is a lever pivoted to a support for movement along an arc to said plurality of positions, said lever being further pivoted for movement in a direction normal to the plane defined by said arc at any of said positions to provide for said additional movement.

Claim 8

The combination defined in claiM 6 wherein said means responsive to movement of said control lever between said positions comprises a plurality of pilot valves (72 to 75) disposed at said support each having a mechanical actuating element (136) and each being operatively coupled to a sea separate one of said power valves, and wherein a plurality of cams (72'' to 75'') are secured to said control lever for movement along said arc therewith, said cams having raised and recessed portions for operating predetermined ones of said pilot valves through said actuating elements thereof at successive positions along said arc.

Claim 9

The combination defined in claim 6 wherein said means responsive to said additional movement is actuated by fluid pressure signals, further comprising a shift valve (69) at said support, said shift valve having a mechanical actuating element (173) and being connected between said source of pressurized fluid and said means responsive to said additional movement; and a spool (119) slidable within said support in a direction normal to the plane defined by said arc and being coupled to said control lever for axial movement thereby upon said additional movement of said lever at any of said positions thereof, said spool having raised and recessed portions for operating said shift valve through said actuating element thereof upon movement of said lever in a direction normal to said arc.

Claim 10

The combination defined in claim 1 further comprising a select lock (184) movable between a first position at which said control is prevented from being moved in said additional direction and a second position at which said control is free to be moved in said additional direction and means responsive to the pressure of fluid from said source to shift said select lock from said first to said second position.

Claim 11

The combination defined in claim 1 further comprising a cam lock (164) movable between a first position at which travel of said control between said positions is blocked and a second position at which said control is free to travel therebetween, and means (167) for shifting said cam lock from said first to said second position in response to the absence of elevated fluid pressure at said actuators.

Claim 12

The combination defined in claim 1 wherein said transmission has a source (191) of lubricating fluid under pressure and has means dividing the lubricating fluid flow therefrom between at least two separate regions of said transmission, wherein said flow dividing means comprises a proportioning valve (192) having an inlet communicated with said source of lubricating fluid and having two outlets each communicating with a separate one of said two regions a of said transmission, said proportioning valve further having a movable member (207) which responds to movement of said control by temporarily altering the distribution of lubricating fluid between said two outlets.

Claim 13

In a transmission having a drive input (26) and a drive output (27) together with a change speed gearing section (22) with a plurality of pneumatic actuators (37 to 41) therein for shifting gear connections to provide a plurality of speed ratios therethrough, said transmission having a pneumatically operated input clutch (31) and a pneumatically operated output means (59 and 61) for disengaging said change speed gears from said drive input and drive output respectively and having brake means (34) operative on said gears whereby said gears may be braked and shifted in a substantially stationary condition, a shift control system comprising: an actuator air supply conduit (84); a plurality of pneumatically piloted power valves (78, to 82,86) each connecting a separate one of said actuators with said air supply conduit and each having a first position communicating the associated actuator with said air supply conduit and a second position venting the associated actuator; a source (89) of air under pressure; a pneumatically piloted actuator control valve (92) connecting said source with said air supply conduit and having a first position communicating said source and said air supply conduit and having a second position venting said conduit; a pneumatically piloted input clutch control valve (93) connected between said source and said input clutch and having a first position communicating said source and said clutch and a second position venting said clutch; a control member (66) movable along a predetermined path through a plurality of positions each corresponding to one of said speed ratios, said control member being movable away from said predetermined path at each of said positions; pilot means (72 to 75) connected to said air source and transmitting pneumatic signals to predetermined ones of said power valves at each of said positions of said control member to shift predetermined ones of said power valves between said first and second positions thereof; and pneumatic control means (96) responding to said movement of said member away from said predetermined path by sequentially shifting said input clutch control valve to said first ps position thereof and then shifting said actuator control valve to first position thereof and shifting said input clutch control valve back to said second position thereof.

Claim 14

In a transmission having a drive input (26) and a drive output (27) together with a change speed gearing section (22) with a plurality of pneumatic actuators (37 to 41) therein for shifting gear connections to provide a plurality of speed ratios therethrough, said transmission having a pneumatically operated input clutch (31) and a pneumatically operated output means (59 and 61) for disengaging said change speed gears from said drive input and drive output respectively and having brake means (34) operative on said gears whereby said gears may be braked and shifted in a substantially stationary condition, a shift control system comprising: an actuator air supply conduit (84); a plurality of pneumatically piloted power valves (78, to 82,86) each connecting a separate one of said actuators with said air supply conduit and each having a first position communicating the associated actuator with said air supply conduit and a second position venting the associated actuator; a source (89) of air under pressure; a pneumatically piloted actuator control valve (92) connecting said source with said air supply conduit and having a first position communicating said source and said air supply conduit and having a second position venting said conduit; a pneumatically piloted input clutch control valve (93) connected between said source and said input clutch and having a first position communicating said source and said clutch and a second position venting said clutch; a control member (66) movable along a predetermined path through a plurality of positions each corresponding to one of said speed ratios, said control member being movable away from said predetermined path at each of said positions; pilot means (72 to 75) connected to said air source and transmitting pneumatic signals to predetermined ones of said power valves at each of said positions of said control member to shift predetermined ones of said power valves between said first and second positions thereof; and pneumatic control means (96) responding to said movement of said member away from said predetermined path by sequentially shifting said input clutch control valve to said first ps position thereof and then shifting said actuator control valve to first position thereof and shifting said input clutch control valve back to said second position thereof.

Claim 15

The combination defined in claim 12 wherein said pneumatic control means responds to movement of said control member back towards said predetermined path by shifting said actuator control valve to said second position thereof while maintaining said input clutch control valve at a said second position thereof.

Claim 16

The combination defined in claim 12 where said input clutch control valve has a pilot connected to said actuator air supply conduit whereby shifting of said actuator control valve from said second to said first position thereof shifts said input clutch control valve from said first of said second position thereof the connection between said input clutch control valve pilot and said actuator air supply conduit having a check valve (102) therein whereby said input clutch control valve may be piloted by said pneumatic control means without simultaneously pressurizing said actuator air supply line.

Claim 17

The combination defined in claim 12 further comprising a safety valve (55'' ) connected between said source of air and said pneumatic control means, and means (55) sensing engagement of said output means and closing said safety valve in response to engagement of said output men means whereby said actuators may only be shifted by said control system when said change speed gears are disengaged from drive output of said transmission.