Auxiliary section actuator control system and method

A method for controlling the shifting of a compound change gear transmission (10) of the type comprising a manually shifted multiple-speed main transmission section (12) shiftable into an engaged or a not engaged condition connected in series with a multiple-speed auxiliary section (14), said auxiliary section including low-speed (168/172) and high-speed (166/170) synchronized jaw clutches (92) shiftable by an actuator (96) to engage either a low-speed or a high speed auxiliary section ratios, respectively, in response to selection by a master selector (98/98A/412, 402 and 404), said method characterized by:

• sensing a selection of a shift of said auxiliary section into a selected one of the low-speed and the high-speed auxiliary section ratios;
• sensing said main transmission section being in either an engaged or in a not engaged condition thereof,
• responding to sensing (i) a selection of a shift into the auxiliary section high-speed ratio and (ii) said main transmission section in the not engaged condition by causing said actuator to urge said auxiliary section high speed synchronized jaw clutches into engagement with a first force level;
• and
• thereafter responding to (i) a continuing selection of a shift into auxiliary section high-speed ratio and (ii) said main transmission section in an engaged condition by causing said actuator to urge said auxiliary section high speed synchronized jaw clutches into engagement with a second force level, said second force level being considerably lower than said first force level.

A method for controlling a shift actuator (220) an auxiliary transmission section (14) of a compound transmission (10) including a main transmission section (12) having engaged and not engaged positions connected in series with said auxiliary transmission section, said auxiliary transmission section including a selectable high-speed ratio and a selectable low-speed ratio each of said auxiliary section ratios engageable by a synchronized jaw clutch assembly (92/128), switch means (98/98A/412) for selecting a desired auxiliary section ratio, said actuator (220) comprising a first force application means (224) for apply a first force in a first axial direction to said synchronized clutch assembly and a second force applications means (222) for applying a second force in a second axial direction opposite said first axial direction to said synchronized clutch assembly, said first force larger than said second force, force in said first axial direction effective to urge said synchronized clutch assembly to engage said high speed ratio and force in said second axial direction effective to urge said synchronized clutch assembly to engage said low speed ratio, said method comprising:

• sensing the current engaged or not engaged position of said main transmission section, and
• applying said second force whenever said main transmission section is in the engaged position thereof (324/328).

A control system for controlling a shift actuator (96) associated with a synchronized jaw clutch (92) for selectively engaging and disengaging a selectable ratio in a first transmission section (14) of a compound transmission (10) comprising first and second (12) multiple speed sections connected in series, said second section shiftable into engaged and not engaged conditions, said system comprising:

• (a) means for sensing selection of engagement of said first transmission section selectable ratio (98/236);
• (b) means for sensing if the second transmission section is in either an engaged or a not engaged condition (204/210/332);
• (c) means (324) for responding to sensing (i) a selection of engagement of said first transmission section selectable ratio and (ii) said second transmission section not engaged by causing said actuator to urge said synchronized jaw clutch into engagement with a first force;
• and
• (d) means (328) for responding to sensing (i) a selection of engagement of said first transmission section selectable ratio and (ii) said second transmission section engaged by causing said actuator to urge said synchronized jaw into engagement with a second force, said second force being smaller than said first force.

A system for controlling the shifting of a compound change gear transmission (10) of the type comprising a manually shifted multiple-speed main transmission section (12) shiftable into an engaged or a not engaged condition connected in series with a multiple-speed auxiliary section (14), said auxiliary section including high-speed (168/172) and low-speed (166/170) synchronized jaw clutches (92) shiftable by an actuator (96) to engage either a low-speed or a high speed (direct) auxiliary section ratio in response to selection by a master selector (98/98A/412), said system characterized by:

• means (98) for sensing a selection of a shift of said auxiliary section into a selected one of the low-speed and the high-speed auxiliary section ratios;
• means (204/310/332) for sensing said main transmission section being in either an engaged or in a not engaged condition thereof,
• means (324) for responding to sensing (i) a selection of a shift into the auxiliary section high-speed ratio and (ii) said main transmission section in the not engaged condition by causing said actuator to urge said auxiliary section high speed synchronized jaw clutches into engagement with a first force level;
• and
• means (328) for thereafter responding to (i) a continuing selection of a shift into auxiliary section high-speed ratio and (ii) said main transmission section in an engaged condition by causing said actuator to urge said auxiliary section high speed synchronized jaw clutches into engagement with a second force level, said second force level being lower than said first force level.

A system for controlling a shift actuator (220) for an auxiliary transmission section (14) of a compound transmission (10) including a main transmission section (12) having engaged and not engaged positions connected in series with said auxiliary transmission section, said auxiliary transmission section including a selectable high-speed ratio and a selectable low-speed ratio each of said auxiliary section ratios engageable by a synchronized jaw clutch assembly (92/128), switch means (98/98A/412) for selecting a desired auxiliary section ratio, said actuator (220) comprising a first force application means (224) for apply a first force in a first axial direction to said synchronized clutch assembly and a second force applications means (222) for applying a second force in a second axial direction opposite said first axial direction to said synchronized clutch assembly, said first force larger than said second force, force in said first axial direction effective to urge said synchronized clutch assembly to engage said high speed ratio and force in said second axial direction effective to urge said synchronized clutch assembly to engage said low speed ration, said system comprising:

• means (204/210/332) for sensing the current engaged or not engaged position of said main transmission section,
• means (324) for applying said first force and not applying said second force when said transmission section is in the not engaged position thereof and the high-speed ratio has been selected, and
• means (324) for applying said second force whenever said main transmission section is in the engaged position thereof (324/328).