Title of Invention

" AN ELECTRO-HYDRAULIC CONTROL SYSTEM TO CONTROL ENGAGEMENT OF TORQUE- TRANSMITTING MECHANISMS IN A TRANSMISSION"

Abstract An electro-hydraulic control system is provided, preferably for a countershaft transmission, with a diagnostic system that uses extensive multiplexing of pressure switches to provide accurate information regarding the position of valves within the control system while minimizing the number of required components.
Full Text GP-308704-PTA-DLT
1
ELECTRO-HYDRAULIC CONTROL SYSTEM WITH MULTIPLEXED PRESSURE
SWITCH DIAGNOSTIC SYSTEM
TECHNICAL FIELD
[0001] The invention relates to an electro-hydraulic control system for a
transmission; specifically, an electro-hydraulic control system having a multiplexed
pressure switch diagnostic system.
BACKGROUND OF THE INVENTION
[0002] Multi-speed power transmissions, particularly those using planetary gear
arrangements, require a hydraulic system to provide controlled engagement and
disengagement, on a desired schedule, of the clutches and brakes or torque-transmitting
mechanisms that operate to establish the ratios within the planetary gear arrangement.
[0003] These control systems have evolved from substantially pure hydraulic
control systems, wherein all of the control signals are produced by hydraulic devices, to
electro-hydraulic control systems, wherein a number of the control signals are produced
by an electronic controller. The electronic controller emits electrical control signals to
solenoid valves, which then issue controlled hydraulic signals to the various operating
valves within the transmission control.
[0004] With many of the early pure hydraulic and first generation electro-
hydraulic control systems, the power transmission utilized a number of freewheel or
one-way devices which smooth the shifting or ratio interchange of the transmission
during both upshifting and downshifting of the transmission. This relieves the
hydraulic control system from providing for the control of overlap between the torque-
transmitting mechanism that was coming on and the torque-transmitting mechanism that
was going off. If this overlap is excessive, the driver feels a shudder in the drivetrain,
and if the overlap is too little, the driver experiences engine flare or a sense of coasting.
The freewheel device prevents this feeling by quickly engaging when the torque
imposed thereon is reversed from a freewheeling state to a transmitting state.

GP-308704-PTA-DLT
2
[0005] The advent of electro-hydraulic devices gave rise to what is known as
clutch-to-clutch shift arrangements to reduce the complexity of the transmission and the
control. These electro-hydraulic control mechanisms are generally perceived to reduce
cost and reduce the space required for the control mechanism.
[0006] In addition, with the advent of more sophisticated control mechanisms,
the power transmissions have advanced from two-speed or three-speed transmissions to
five-speed and six-speed transmissions. In at least one presently available six-speed
transmission, just five friction devices are employed to provide six forward speeds,
neutral condition, and a reverse speed.
[0007] Countershaft transmissions arc often a desirable design option as they
typically have low spin losses and offer wide ratio coverage. The relatively large
number of clutches sometimes associated with countershaft transmissions may require
double transition shifts. To reduce the number of components to the extent possible,
clutches are sometimes reused in different speed ratio ranges.
SUMMARY OF THE INVENTION
[0008] It is desirable to provide diagnostic capabilities to determine if an
electro-hydraulic control system is operating as commanded by a controller, and to
ensure prompt adjustment in the event of a failure to operate as desired.
[0009] An electro-hydraulic control system is pro\ ided with a diagnostic system
that uses extensive multiplexing of pressure switches to provide accurate information
regarding the position of valves within the control system while minimizing the number
of required components. The pressure switch diagnostic system has first, second, third
and fourth pressure switches, each having a high and a low logic state. The electro-
hydraulic control system further includes first and second logic valves as well as first,
second, third and fourth trim valves, each movable between a respective first and second
position. Two of the pressure switches each report the high or the low logic state to the
controller in accordance with a relatively high or a relatively low fluid pressure at a
respective one of two of the trim valves corresponding with the position of the respective
trim valve and the position of the first logic valve; i.e., these two pressure switches are

GP-308704-PTA-DLT
3
multiplexed to determine the positions of the two trim valves and of the first logic valve.
The other two pressure switches also each report a high or a low logic state in accordance
with the relative fluid pressure at a respective one of the other two trim valves,
corresponding with the positions of these two respective trim valves and the position of
the second logic valve, i.e.. these two pressure switches are multiplexed to determine the
positions of the other two trim valves and of the second logic valve. As used herein,
switches are "multiplexed" when they have more than one function, such as when they
are able to report logic states corresponding with the position of more than one valve.
Traditionally, a separate pressure switch is required for each valve; accordingly the
electro-hydraulic control system minimizes the number of required components and
associated cost, packaging space requirements and assembly time.
[0010] The electro-hydraulic control system may include a three position dog-
clutch actuator valve selectively movable between three positions to control movement of
a three-position dog clutch. Fifth and sixth pressure switches are provided in the
diagnostic system to report a combination of logic states indicative of the position of the
dog clutch actuator valve. Preferably, the controller is operable to determine whether the
reported logic states of the pressure switches are consistent with those corresponding with
positions commanded by the controller to achieve a desired speed ratio.
[0011] The electro-hydraulic control system may further include a fifth trim valve
and a third logic valve, with a corresponding seventh and eighth pressure switch used to
report one of a high and a low logic state to the controller corresponding with the
positions of these respective valves.
[0012] Preferably, the electro-hydraulic control system is used with a
transmission having seven torque-transmitting mechanisms in addition to the dog clutch
that are selectively engagable to achieve at least nine forward and two reverse speed
ratios without using any pressure switches in addition to the eight pressure switches
described above.
[0013] The above features and advantages and other features and advantages of
the present invention are readily apparent from the following detailed description of the

GP-308704-PTA-DLT
4
best modes for carrying out the invention when taken in connection with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIGURE 1 is a schematic representation of a countershaft transmission
having torque-transmitting mechanisms engaged and disengaged via an electro-hydraulic
control system within the scope of the invention;
[0015] FIGURES 2A and 2B are a schematic representation of a hydraulic control
portion of the electro-hydraulic control system of Figure 1 having valves to control
engagement and disengagement of the torque-transmitting mechanisms of the
transmission of Figure 1; and
[0016] FIGURE 3 is a table indicating the state of many of the valves shown in
Figures 2A and 2B for each speed ratio achievable by the transmission of Figure 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Referring to the drawings, wherein like reference numbers represent the
same or corresponding parts throughout the several views, there is shown in Figure 1 a
powertrain 10. The powertrain 10 includes a power source or engine 12, a torque
converter 14 and a countershaft transmission 16. The torque converter 14 is connected
with the engine 12 and with a transmission input member 18 via a turbine 20. Selective
engagement of a torque converter clutch TCC allows the engine 12 to be directly
connected with the input shaft 18, bypassing the torque converter 14. The input
member 18 is typically a shaft, and may be referred to as an input shaft herein. The
torque convener 14 includes the turbine 20, a pump 24 and a stator 26. The converter
stator 26 is grounded to a casing 30 through a typical one-way clutch that is not shown.
A damper 28 is operatively connected to the engaged torque converter clutch TCC for
absorbing vibration.
[0018] The transmission 16 includes a plurality of intermeshing gears, a first
countershaft 32. a second countershaft 34, an intermediate shaft 36 and an output member
38, which may be a shaft. The transmission 16 further includes a plurality of torque-

GP-308704-PTA-DLT
5
transmitting mechanisms, including the torque converter clutch TCC. six rotating
clutches: C1, C2, C3, C4, C5 and C7; and one stationary clutch C6. Torque is transferred
from the input member 18 to the output member 38 along various powerflow paths
through the transmission 16 depending on which of the plurality of selectively engagable
torque-transmitting mechanisms are engaged.
[0019] Clutch C4 is selectively engagable to connect the input member 18 for
rotation with the intermediate shaft 36. Gear 40 rotates with the input member 18 and
continuously intermeshes with gear 42, which rotates with the second countershaft 34.
Gear 44 rotates with input member 18 and continuously intermeshes with gear 46, which
rotates with the first countershaft 32. Gear 48 rotates with sleeve shaft 51 which is
concentric with first countershaft 32 and is selectively connectable with the first
countershaft 32 by engagement of clutch C3. Gear 48 continuously intermeshes with
gear 50, which rotates with intermediate shaft 36. Gear 50 also continuously intermeshes
with gear 52, which rotates with sleeve shaft 53. which is concentric with second
countershaft 34 and is selectively connectable for rotation with second countershaft 34 by
engagement of clutch C5. Gear 54 rotates with sleeve shaft 55 which is concentric with
and selectively connectable for rotation with first countershaft 32 by engagement of
clutch C1. Gear 54 continuously intermeshes with gear 56 (in a different plane than the
two-dimensional schematic, as indicated by the dashed lines therebetween). Gear 56
rotates about and is selectively connectable for rotation with a sleeve shaft 57 by the
positioning of a dog clutch DOG in a reverse position indicated as R. The sleeve shaft 57
is selectively connectable for rotation with the second countershaft 34 by engagement of
clutch C2. Gear 58 rotates with the sleeve shaft 55 and continuously intermeshes with
gear 60, which rotates with the intermediate shaft 36. Gear 60 continuously intermeshes
with the gear 62. which is selectively connectable for rotation with the sleeve shaft 57 by
positioning of the dog clutch DOG in a forward position indicated by F in the Figure 1.
[0020] The transmission 16 further includes a planetary gear set 64 with a sun
gear member 66 connected for rotation with the intermediate shaft 36. a ring gear
member 68 selectively connectable for rotation with the intermediate shaft 36 by
engagement of clutch C7, a carrier member 70 connected for rotation with the output

GP-308704-PTA-DLT
6
member 38 and rotatably supporting planet gears 72 that intermesh with both the sun gear
member 66 and the ring gear member 68. A clutch C6 is selectively engagable to ground
the ring gear member 68 to the stationary member 30.
[0021] In a preferred embodiment, the following gear tooth counts are used: gear
40 has 39 teeth; gear 42 has 37 teeth; gear 46 has 40 teeth; gear 44 has 3 1 teeth; gear 48
has 34 teeth; gear 50 has 31 teeth; gear 52 has 34 teeth; gear 54 has 62 teeth; gear 56 has
46 teeth; gear 58 has 26 teeth; gear 60 has 44 teeth; gear 62 has 26 teeth; ring gear
member 68 has 85 teeth and sun gear member 66 has 35 teeth. B\ the selective
engagement of the torque-transmitting mechanisms FCC. C1, C2, C3, C4, C5, C6, C7
and DOG according to the table of Figure 3, and assuming the tooth counts listed above,
the following sample numerical speed ratios are attained between the input member 12
and the output member 14 for the following speed ratio ranges: second reverse speed
ratio range (R2): 2.18; first reverse speed ratio range (R1): 7.42; first forward speed ratio
(1st 7.49; second forward speed ratio (2nd): 5.51; third forward speed ratio (3rd): 4.03;
fourth forward speed ratio (4th): 2.97; fifth forward speed ratio (5th): 2.18; sixth forward
speed ratio (6th): 1.61; seventh forward speed ratio (7th): 1.18; eighth forward speed ratio
(8th): 1.00; ninth forward speed ratio (9th): 0.87. Alternate solenoid-energizing schemes
are available for the first, third, fifth and seventh speed ratio ranges with one or more of
the logic valves in different positions for the same range. For example, three different
alternate seventh forward speed ratios (7th'), (7th") and (7th'') are available by
energizing solenoids associated with different ones of the logic valves X. Y, Z and W, as
discussed below and indicated in Figure 3.
[0022] The selective engagement and disengagement of the torque-transmitting
mechanisms is controlled by an electro-hydraulic control system 74, which is shown in
further detail in Figures 2A and 2B. The electro-hydraulic control system 74 includes an
electronic controller 76. which may be one or more control units and is referred to as
ECU in Figure 1, as well as a hydraulic control portion 100 referred to as HYD in Figure
1. The electronic controller 76 is programmable to provide electrical control signals to
the hydraulic control portion 100 to establish the fluid pressures that control engagement

GP-308704-PTA-DLT
7
and disengagement of the torque-transmitting mechanisms TCC, C1, C2, C3, C4, C5, C6,
C7 and DOG.
[0023] Referring to Figures 2A and 2B, the hydraulic control portion 100 includes
a main regulator valve 104, a control regulator valve 106, an EBF (exhaust back flow)
regulator valve 108, a converter flow valve 110, and a lube regulator valve 112. The
main regulator valve 104 is in fluid communication with a hydraulic pump 114, such as a
variable volume pump, that draws fluid from a reservoir 116 for delivery to a main
passage 118. The control regulator valve 106 is in fluid communication with the main
regulator valve 104, and establishes a reduced control pressure within passage 117, which
is then communicated to other valves described below, depending upon their position.
The EBF regulator valve 108 is operable to vent pressurized fluid within passage 117 to
exhaust should an over pressurized condition occur. Pump 119 is an engine-driven pump
that also draws fluid from reservoir 116 and that controls the lubrication pressure to a
lubrication system 121 and provides cooling fluid to a transmission cooling system 123.
[0024] The hydraulic control portion 100 includes many solenoid valves, such as
variable pressure type solenoid valves PCS1, PCS2, PCS3, PCS4, PCS5, PCS6, and
PCS7, and shift-type (i.e., on/off type) solenoid valves SS1, SS2 and SS3. Each solenoid
valve is in electric signal communication with the control unit 76 and is actuated upon
receipt of a control signal therefrom. The solenoid valves PCS1, PCS7 and PCS5 are
normally high or normally open-type solenoid valves, while the remaining solenoid
valves PCS2, PCS3, PCS4. PCS6, SSI. SS2 and SS3 are normally low or normally
closed-type solenoid valves. As is well known, an open solenoid valve will distribute
output pressure in the absence of an electrical signal to the solenoid. As used herein, a
normally high-type solenoid is energized by a control signal to be placed in and to remain
in a closed position, while a normally low-type valve is energized to be placed in and to
remain in a closed position.
[0025] The hydraulic control portion 100 also includes a plurality of trim valves
120, 122, 124, 126, 128 and 130. Trim valve 120, solenoid valve PCS1 and a spring-
biased relief valve 132 are a first trim system that, as will be further explained below, is
multiplexed to control engagement and disengagement of both clutch C1 and clutch C4.

GP-308704-PTA-DLT
8
Trim valve 122, solenoid valve PCS2 and accumulator valve 134 are a second trim
system that is multiplexed to control engagement and disengagement of both clutch C2
and C5. Trim valve 124, solenoid valve PCS3 and accumulator valve 136 are a third trim
system that is multiplexed to control engagement and disengagement of both clutch C3
and C7 (for clutch C7, only for some speed ratios). Trim valve 126, solenoid valve
PCS4, converter flow valve 110 and accumulator valve 138 are a fourth trim system that
controls engagement of the torque-converter clutch TCC. Trim valve 128, solenoid valve
PCS6 and accumulator valve 140 are a fifth trim system that controls engagement and
disengagement of clutch C6. Trim valve 130, solenoid valve PCS7 and accumulator
valve 142 are a sixth trim system that controls engagement of clutch C7 in those speed
ratios for which the third trim system is not controlling. For each trim system, actuation
of the associated solenoid valve causes actuation of the respective trim valve and clutch
(or one of the respective clutches in the case of multiplexed trim valves). Solenoid valve
PCS5 and the main regulator valve 104 control the main pressure level in main passage
118 from the pump 114.
[0026] The hydraulic control portion 100 further includes logic valves X. Y. Z
and W, and a dog clutch actuator valve 144. Solenoid SS1 receives an electrical control
signal from the control unit 76 to actuate or shift, thereby shifting logic valve X. The
position of logic valve X controls in part the position of dog clutch actuator valve 144, as
the downward shift on the logic valve X (moving from a spring-set position to a
pressure-set position) caused by energizing solenoid SS1 allows pressurized fluid
provided from passage 118 in passage 143 to pass through the logic valve X into passage
146 in communication with the dog clutch actuator valve 144. Solenoid valve SS2
receives an electrical control signal from the control unit 76 to actuate or shift, thereby
shifting logic valve Y, allowing pressurized fluid provided from passage 118 in passage
143 to pass through logic valves X and Y into outlet passage 148 in communication with
dog clutch actuator valve 144. Solenoid valve SS3 receives an electrical control signal
from the control unit 76 to actuate or shift, thereby allowing pressurized fluid from
passage 164 to outlet passage 151 in communication with both logic valve W and dog

GP-308704-PTA-DLT
9
clutch actuator valve 144. The pressurized fluid in passage 151 causes the logic valve W
to shift downward in Figure 2B, allowing fluid in passage 155 to be exhausted.
[0027] The position of logic valve Z is controlled by the position of the dog
clutch actuator valve 144. (It should be appreciated that the dog clutch actuator valve
144 has two separately movable valve components, a spool valve 157 and a plug valve
159.) Specifically, when the dog clutch actuator valve 144 is in a reverse position (as
depicted in Figure 2B) controlled pressure fluid provided to passage 161 from passage
117 is not provided to logic valve Z through passage 163. However, when the dog clutch
actuator valve is in either the neutral position or the forward position, the controlled
pressure fluid from passage 161 is provided to passage 163 through restricted passage
165A to move the logic valve Z from a spring-set position to a pressure-set position.
Restricted passage 165B is in fluid communication with switch SW8 and restricted
passage 165C is in fluid communication with passage 153. Two exhaust ports. EX1 and
EX2, are in fluid communication with the dog clutch actuator valve 144 and two switches
SW7 and SW8 are in communication with the valve 144 to monitor its position based on
pressure readings.
Pressure Switch Diagnostic System
[0028] Electrical signals are sent to the electronic controller 76 based on fluid
pressure in the hydraulic control portion 100 to provide feedback information such as
information indicative of valve positions. Various pressure sensitive switches, also
referred to as pressure switches, which provide such feedback are indicated as pressure
switches SW1. SW2, SW3, SW4, SW5. SW6, SW7 and SW8 in Figures 2A and 2B.
Each pressure switch can monitor and report a high logic state and a low logic state.
corresponding with a relatively high pressure and low pressure, respectively, of the fluid
at the switch. The pressure switches are configured to report the high logic state at or
above a predetermined pressure and the low logic state below the predetermined pressure.
Accordingly, as used herein, a "relatively high pressure" is a pressure at or above a
predetermined pressure and a "relatively low pressure" is a pressure below the
predetermined pressure. The ability to monitor the above-mentioned valves and detect a

GP-308704-PTA-DLT
10
change, or lack of change, in valve position is of importance to provide continuous and
reliable operation of the transmission 16.
[0029] The pressure switches SW1, SW2, SW3, SW4, SW5, SW6, SW7 and
SW8, and the electronic controller 76 that analyses the state of the pressure switches form
a diagnostic system for the transmission 16. Each pressure switch SW1, SW2, SW3,
SW4, SW5, SW6, SW7 and SW8 is operatively connected with the controller 76 with a
transfer conductor (e.g., an electrical wire) capable of carrying electrical signals
therebetween. The controller 76 contains data representing the expected logic state of
each of the pressure switches in each of the speed ratio ranges in which the transmission
16 operates. If one or more of the pressure switches detects and reports a logic state to
the controller 76 that does not correspond to the expected logic state of that particular
pressure switch in the particular speed ratio in which the transmission 16 is operating, the
controller 76 will determine whether it is necessary to shift the transmission 16 to a
different speed ratio range, including to one of the predetermined drive-home modes
(also referred to as failure modes), discussed below, until the transmission can be
maintenanced.
[0030] It should be appreciated that extensive multiplexing is used to enable at
least some of the switches to monitor the position of more than one valve, thus
minimizing the number of required components. Several of the pressure switches are
multiplexed to detect the positions of both a trim valve and a logic valve. Specifically,
Pressure switches SW3 and SW4 are multiplexed with trim valves 122 and 124 as well as
logic valve X. Passage 174 and passage 180 establish fluid communication between
logic valve X and trim valves 122 and 124. When logic valve X is in a spring-set
position, pressurized fluid from passage 118 is delivered in passage 174 to the trim valves
122 and 124. When trim valve 122 is in a pressure-set position, the pressurized fluid in
passage 174 is not in communication with pressure switch SW3. Instead, exhausting
passage 180 is in communication with pressure switch SW3, which reports a low logic
state for diagnostic purposes. When trim valve 122 is in a spring-set position, the
pressurized fluid in passage 174 is in communication with pressure switch SW3. which
reports a high logic state for diagnostic purposes. When trim valve 124 is in a spring-set

GP-308704-PTA-DLT
11
position, pressurized fluid in passage 174 is blocked by the middle land of the trim valve
124 from communicating with pressure switch SW4. Instead, exhausting fluid in channel
180 is communicated to pressure switch SW4, which reports a low logic state for
diagnostic purposes. When trim valve 124 is in a pressure-set position, pressurized fluid
in passage 174 is in communication with pressure switch SW4, which reports a high logic
state for diagnostic purposes. Fluid in passage 180 is blocked from communication with
pressure switch SW4.
[0031] When logic valve X is in a pressure-set position, pressurized fluid from
channel 118 is blocked by a land in logic valve X from communicating with passage 174.
which exhausts. Control pressure fluid from passage 117 is communicated to passage
180. When trim valve 122 is in a spring-set position, the unpressurized fluid in passage
174 is in communication with pressure switch SW3, which reports a low logic state for
diagnostic purposes. When trim valve 122 is in a pressure-set position, the unpressurized
fluid in passage 174 is blocked from communication with pressure switch SW3. Instead,
the control pressure fluid in passage 180 communicates with switch SW3, which reports a
high logic state for diagnostic purposes. When trim valve 124 is in a spring-set position,
the control pressure fluid in passage 180 is in communication with pressure switch SW4,
which reports a high logic state for diagnostic purposes. When trim valve 124 is in a
pressure set position, the exhausting passage 174 is in communication with pressure
switch SW4. which reports a low logic state for diagnostic purposes. As is evident from
the above, a change in position of the logic valve X causes a change in logic state
reported by the pressure switches SW3 and SW4. regardless of the position of the trim
valves 122 and 124 (assuming the trim valves do not also change position when the logic
valve X changes position).
[0032] The controller 76 monitors the state of the pressure switches SW3 and
SW4 to determine if the trim valves 122 and 124 are failing to apply or to release the
clutches C2, C5 and C3, C7, respectively, as commanded, and whether logic valve X is
failing to move to either a spring-set (failing-on) or a pressure-set (failing-off) position.
That is. when the controller 76 has commanded a certain speed ratio range by energizing
a certain combination of solenoid valves, as set forth in Figure 3. if either or both of the

GP-308704-PTA-DLT
12
pressure switches SW3 and SW4 reports a logic state that is not consistent with that
expected in the commanded speed ratio range, the controller 76 will determine that one or
both of the trim valves 122 and 124 or logic valve X is failing to change position in
response to a respective electrical signal (or the cessation of an electrical signal) sent to a
respective solenoid valve PCS2, PCS3 or SS1.
[0033] Additionally, pressure switches SW1 and SW2 are multiplexed with trim
valves 120 and 128 and logic valve Y. Passage 171 and passage 179 establish fluid
communication between logic valve Y and trim valves 120 and 128. When logic valve Y
is in a spring-set position, pressurized fluid from passage 118 fed through passage 143
and passage 169 to passage 171 is in communication with trim valves 120 and 128.
Passages 175 and 179 are exhausting. When trim valve 120 is in a spring set position, the
pressurized fluid in passage 171 is in communication with pressure switch SW2, which
reports a high logic state for diagnostic purposes. When trim valve 120 is in a pressure
set position, a land on trim valve 120 blocks passage 171 from communication with
pressure switch SW2. Instead, exhausting fluid in passage 175 is in communication with
pressure switch SW2. which reports a low logic state for diagnostic purposes. When trim
valve 128 is in a spring-set position, the pressurized fluid in passage 171 is blocked by a
land on trim valve 128 from communication with pressure switch SW1. Instead,
exhausting fluid in passages 175 and 179 communicates with pressure switch SW1.
which reports a low logic state for diagnostic purposes.
[0034] When logic valve Y is in a pressure-set position, passage 175
communicates control pressure fluid routed from passage 117 to the trim valves 120 and
128, and passage 171 exhausts. When trim valve 128 is in a spring-set position, control
pressure fluid in passage 175 and 179 communicate with switch SW1, which reports a
high logic state for diagnostic purposes. When trim valve 128 is in a pressure set
position, a land on trim valve 128 blocks passage 179 from communication with pressure
switch SW1. Instead, exhausting passage 171 is in communication with pressure switch
SW1, which reports a low logic state for diagnostic purposes. When trim valve 120 is in
a spring-set position, a land on trim valve 120 blocks the control pressure fluid in passage
175 from communication with pressure switch SW1. Instead, exhausting passage 171

GP-308704-PTA-DLT
13
communicates with switch SW1, which reports a low logic state for diagnostic purposes.
When trim valve 120 is in a pressure set position, control pressure fluid in passage 175
communicates with pressure switch SW1, which reports a high logic state for diagnostic
purposes. Exhausting passage 171 is blocked from communication with switch SW1 by a
land on trim valve 120. As is evident from the above, a change in position of logic valve
Y causes a change in logic state reported by the pressure switches SW1 and SW2,
regardless of the position of trim valves 120 and 128 (assuming the trim valves do not
also change position when the logic valve Y changes position).
[0035] The controller 76 monitors the state of the pressure switches SW1 and
SW2 to determine if the trim valves 128 and 120, respectively, are failing to apply or
release the clutches C6 and C1 or C4 as desired, and whether the logic valve Y is failing
to move to either a spring-set position (failing-on) or to a pressure-set position
(failing-off). That is, when the controller 76 has commanded a certain speed ratio range
by energizing a certain combination of solenoid valves, as set forth in Figure 3, if either
or both of the pressure switches SW1 and SW2 report a logic state that is inconsistent
with that expected in the commanded speed ratio range, the controller 76 will determine
that one or both of the trim valves 120 and 128 or logic valve Y is failing to change
position in response to a commanded electrical signal (or the cessation of an electrical
signal) sent to the respective solenoid valve PCS1, PCS6 or SS2 associated with the trim
valve 120, 128 or logic valve Y, respectively.
[0036] Pressure switch SW5 is used for detecting the position of trim valve 130.
When trim valve 130 is in a spring-set position, a land on trim valve 130 blocks control
pressure fluid from communication with pressure switch SW5. Instead, exhaust fluid in
passage 182 communicates with switch SW5, which reports a low logic state for
diagnostic purposes. When trim valve 130 is in a pressure-set position, control pressure
fluid from passage 117 through passage 161 communicates with pressure switch SW5,
which reports a high logic state for diagnostic purposes. If the pressure switch SW5 does
not report the expected logic state for a commanded speed ratio range, the controller 76
determines whether the trim valve 130 is failing to change position in response to a
change in the electrical signal commanded to solenoid valve PCS6.

GP-308704-PTA-DLT
14
[0037] Pressure switch S W6 is used for detecting the position of logic valve Z.
When logic valve Z is in a spring-set position, control pressure fluid from passage 117
fed through passage 161 is able to exhaust through the exhaust port F.X adjacent the logic
valve Z, and the pressure switch SW6 reports a low logic state for diagnostic purposes.
When logic valve Z is in a pressure-set position, a land on logic valve Z blocks exhaust of
the control pressure fluid, and the switch SW6 reports a high logic state for diagnostic
purposes. If the pressure switch SW6 does not report the expected logic state for a
commanded speed ratio range, the controller 76 determines whether the logic valve Z is
failing to change position in response to a change in the position of the dog clutch
actuator valve 144, which controls the position of the logic valve Z.
[0038] Pressure switches SW7 and SW8 are used for detecting the position of the
three-position dog clutch actuator valve 144. When the dog clutch actuator valve 144 is
in the reverse position R, control pressure fluid fed through passage 165A is in
communication with exhaust port EX1, so pressure switch SW7, which is also in
communication with exhaust port EX1, reports a low logic state for diagnostic purposes.
A land on dog clutch actuator valve 144 blocks pressure switch SW8 from exhausting
through the cavity formed by the portion of the central bore (which is attached to a sump)
shown just below pressure switch SW8, so control pressure fluid fed through passage
165B causes pressure switch SW8 to report a high logic state for diagnostic purposes.
[0039] When dog clutch actuator valve 144 is in a forward position, the spool
valve 157 shifts upward with respect to the reverse position shown in Figure 3, and a land
on spool valve 157 blocks control pressure fluid in passage 165A from communication
with exhaust port EX1. Control pressure fluid is fed to passage 163 and switch SW7,
which reports a high logic state for diagnostic purposes. Control pressure fluid fed
through passage 165B is able to exhaust, and switch SW8 reports a low logic state for
diagnostic purposes.
[0040] If either or both of the pressure switches SW7 and SW8 do not report the
expected logic state for a commanded speed ratio range, the controller 76 determines
whether the dog clutch actuator valve 144 is failing to change position in response to a
change in the position of logic valve X or Y or a change in electrical signal sent to

GP-308704-PTA-DLT
15
solenoid valve SS3 (all of which affect the position of the dog clutch actuator valve 144).
For example, such an inconsistency with expected logic states of the pressure switches
SW7 and SW8 may indicate that the dog clutch actuator valve 144 is getting a stuck
signal pressure (i.e.. pressurized fluid) in passage 151 due to energizing of solenoid valve
SS3 to attempt to move the dog clutch actuator valve 144 to the reverse or to the forward
position, (stuck apply) rather than the desired apply and release of hydraulic pressure to
change position of the dog clutch actuator valve 144 (as will be confirmed by the
pressure switches SW7 and SW8) to minimize overloading of the dog clutch DOG of
Figure 1.
[0041] Referring to Figure 3. a table shows the steady-state conditions of the
following valves during available speed ratios (also referred to as ranges): logic valves
W, X. Y and Z, dog clutch actuator valve 144, and pressure control solenoid valves
PCS1, PCS2. PCS3, PCS4, PCS5, PCS6 and PCS7. With respect to the logic valves W.
X, Y and Z, an "0" in the chart indicates that the valve is in a spring-set position
("unstroked") and a "1" indicates that the valve is in a pressure-set position ("stroked").
With respect to the dog clutch actuator valve 144, an "R" indicates that the dog clutch
actuator valve 144 is in a reverse position (with the spool valve 157 and plug valve 159
each in their relatively lowest positions as they appear in Figure 2B). Sw itch SW7 will
indicate a relatively low pressure condition (i.e.. a low logic state) and switch SW8 will
indicate a relatively high pressure condition (i.e., a high logic state). Exhaust ports EX1
and EX2 will exhaust. An "F" indicates that the dog clutch actuator valve 144 is in a
forward position, with the spool valve 157 in its relatively highest position with an
uppermost part of the spool valve 157 shown in Figure 2B experiencing exhaust pressure
fluid in passage 146 and a lowest portion of the plug valve 159 experiencing exhaust
pressure in passage 148. and flow of controlled pressure from passage 1 17 permitted
across the valve to passage 163. Switch SW7 will indicate a relatively high pressure
condition and switch SW8 will indicate a relatively low pressure condition. Exhaust
ports EX1 and EX2 will exhaust. An "N" indicates that the dog clutch actuator valve 144
is in a neutral position in which the upper and lower ends of the valve are subjected to
main pressure fluid from passages 146 and 148. respectively, and flow of controlled

GP-308704-PTA-DLT
16
pressure fluid from passage 117 permitted across the valve 144 to both passages 153 and
163. Switches SW7 and SW8 will both indicate a relatively high pressure condition.
Exhaust ports EX1 and EX2 will exhaust.
[0042] With respect to the columns in Figure 3 for the respective pressure control
solenoid valves PCS1, PCS2, PCS3, PCS4, PCS6 and PCS7. the clutch listed for a
particular speed ratio in a column for a particular solenoid valve indicates that the
solenoid valve is in fluid communication with that clutch during that speed ratio. If the
box listing the clutch is not shaded, then the solenoid is not energized in the case of a
normally closed-type solenoid or is energized in the case of a normally open-type
solenoid, and the listed clutch is not engaged. If the box is shaded, then the solenoid is
energized in the case of a normally closed-type solenoid or is not energized in the case of
a normally-open type solenoid, and the listed clutch is thereby engaged. With respect to
PCS5, "MM" indicates that the pressure control solenoid PCS5 is being energized as
necessary to control an output pressure in passage 149 that controls a pressure bias on the
main regulator valve 104. The pressure control solenoid PCS5, by varying the pressure
within passage 149. is operable to vary the operating characteristics of the main regulator
valve 104. thereby modulating the pressure within the passage 118. The column of
Figure 2 labeled "Exhaust" indicates which of the clutches are being exhausted (emptied
of pressurized fluid) during each of the various speed ratios.
[0043] As is apparent from the chart of Figure 3, the pressure control solenoid
PCS1 and the first trim system of which it is a part is multiplexed to control the
engagement and disengagement of both clutches C1 and C4. The pressure control
solenoid PCS2 and the second trim system of which it is a part is multiplexed to control
the engagement and disengagement of both clutches C2 and C5. The pressure control
solenoid PCS3 and the third trim system of which it is a part is multiplexed to control the
engagement and disengagement of both clutches C3 and C7 (at least for ranges reverse
(R2), reverse (R1). startup and neutral conditions, and the first forward speed ratio range
(1st). For ranges above the first forward speed ratio range (1st), pressure control
solenoid PCS7 controls the engagement and disengagement of clutch C7. Pressure
control solenoid PCS4 controls the engagement of the torque-converter clutch TCC.

GP-308704-PTA-DLT
17
Pressure control solenoid PCS6 controls the engagement of clutch C6. except in speed
ratio ranges (7th"). (7th'"). (8th) and (9th). In these speed ratios, clutch C6 is not
engaged, and is also not affected by the state of the pressure control solenoid PCS6. The
dashed lines in the chart of Figure 3 indicate that the respective pressure control solenoid
and trim system are decoupled from the respective clutch. The column labeled "Exhaust"
indicates, for each speed ratio range, clutches that are being exhausted through the logic
valves. The remaining clutches that are not engaged are exhausted through the associated
trim valves.
[0044] Figures 2A and 2B depict the hydraulic control portion 100 with the
positioning of the valves corresponding to the second reverse speed ratio range (R2) of
Figure 3. When operating in the reverse speed ratio range (R2), the trim valves 122 and
124 are pressure-set and trim valve 120 is spring-set by energizing the solenoids PCS2,
PCS3, and PCS1, respectively. The remaining trim valves 126, 128 and 130, and the
logic valves X. Y, Z and W remain in a spring-set position. With the above-stated valve
configuration, the main pressure in passage 1 18 is in fluid communication with clutches
C2 and C7, which will engage, while clutches C3, C4, and C5 will exhaust. To effect the
engagement of clutch C2, pressurized fluid from the passage 150 is communicated to the
outlet passage 152 of the trim valve 122. Because it is in the spring-set position, the logic
valve Y will communicate the fluid within the passage 152 to the clutch C2. To effect
the engagement of the clutch C7, pressurized fluid within the passage 154 is
communicated to the outlet passage 156 of the trim valve 124. Because it is in the
spring-set position, the logic valve Z will communicate the fluid within passage 156 to
the clutch C7. Pressure switches SW1. SW3, SW5, SW6 and SW7 report a low logic-
state and pressure switches SW2. SW4 and SW8 report a high logic state for diagnostic
purposes.
[0045] When operating in the first reverse speed ratio range (R1). the trim valves
122 and 128 are pressure-set and trim valve 120 is spring-set by energizing solenoids
PCS2, PCS6 and PCS1. respectively. The remaining trim valves 124, 126 and 130, and
the logic valves X, Y, Z and W remain in a spring-set position. With the above-stated
valve configuration, the main pressure in passage 118 is in fluid communication with

GP-308704-PTA-DLT
18
clutches C2 and C6, which will engage, while clutches C3, C4. and C5 will exhaust. To
effect the engagement of clutch C2, pressurized fluid from the passage 150 is
communicated to the outlet passage 152 of the trim valve 122. Because it is in the
spring-set position, the logic valve Y will communicate the fluid within the passage 152
to the clutch C2. To effect the engagement of clutch C6. pressurized fluid within passage
158 is communicated to outlet passage 160 of trim valve 128. Because they are in the
spring-set position, logic valve X and logic valve Y communicate the fluid within
passage 1 18 to passage 158.
[0046] Pressure switches SW3, SW4, SW5, SW6 and SW7 report a low logic
state and pressure switches SW1, SW2 and SW8 report a high logic state for diagnostic
purposes.
[0047] When starting the engine 12 of Figure 1 (indicated in Figure 3 as
"startup"), the logic valve X and the trim valve 128 are pressure-set and trim valve 120 is
spring-set by energizing the solenoids SS1, PCS6, and PCS1, respectively. The
remaining trim valves 120, 124, 126 and 130, and logic valves Y, Z and W remain in a
spring-set position. With the above-stated valve configuration, the main pressure in
passage 118 is in fluid communication with clutch C6, which will engage, while clutches
C1, C3, and C5 will exhaust. To effect the engagement of clutch C6, pressurized fluid
within passage 158 is communicated to outlet passage 160 of trim valve 128. The
pressure-set position of logic valve X and the spring-set position of logic valve Y allow
fluid in passage 118 to be communicated to passage 158.
[0048] When operating in the neutral state, indicated as "N" in Figure 3. the trim
valve 128 is pressure-set and trim valve 120 spring set by energizing solenoids PCS6 and
PCS1, respectively. The remaining trim valves 124, 126 and 130, and the logic valves X.
Y, Z and W remain in a spring-set position. With the above-stated valve configuration,
the main pressure in passage 118 is in fluid communication with clutch C6, which will
engage, while clutches C3, C4 and C5 will exhaust. To effect the engagement of clutch
C6, pressurized fluid within passage 158 is communicated to outlet passage 160 of trim
valve 128. Because they are in the spring-set position, logic valve X and logic valve Y
communicate the fluid within passage 118 to passage 158. Pressure switches SW4, SW5,

GP-308704-PTA-DLT
19
SW6 and SW7 report a low logic state and pressure switches SW1. SW2, SW3 and SW8
report a high logic state for diagnostic purposes.
[0049] When operating in the first forward speed ratio range (1st), the trim valves
120 and 128 are pressure-set by not energizing solenoid PCS1 and energizing PCS6.
respectively. (Note that, because PCS1 is normally open, in a steady state condition, no
energizing control signal is required in order to pressure-set the trim valve 120.) The
remaining trim valves 122, 124, 126 and 130, and the logic valves X, Y, Z and W remain
in a spring-set position. With the above-stated valve configuration, the main pressure in
passage 118 is in fluid communication with clutches C1 and C6, which will engage,
while clutches C3. C4, and C5 exhaust. To effect engagement of clutch C1, pressurized
fluid within passage 150 is communicated to outlet passage 162 of trim valve 120. To
effect the engagement of clutch C6, pressurized fluid within passage 158 is
communicated to outlet passage 160 of trim valve 128. Because they are in the spring-set
position, logic valve X and logic valve Y communicate the fluid within passage 1 18 to
passage 158. Pressure switches SW2, SW4, SW5, SW6 and SW7 report a low logic
state and pressure switches SW1, SW3 and SW8 report a high logic state for diagnostic
purposes.
[0050] When operating in the alternate first forward speed ratio range (1st'). in
addition to pressure-setting trim valves 120 and 128 as in the first forward speed ratio
range (1st), trim valve 126 is also pressure-set by energizing solenoid valve PCS4.
Solenoid valve SS3 is also energized to shift the dog clutch actuator valve 144 to a
forward position, thus blocking exhaust of controlled pressure fluid from passage 117 in
passage 161 provided to passage 163 through restricted passage 165A. to move the logic
valve Z from a spring-set position to a pressure-set position. Solenoid valve SS3 is no
longer energized after the dog clutch actuator valve 144 moves to the forward position, as
confirmed by the pressure switches SW7 and SW8 shown in communication with the dog
clutch actuator valve 144, and control pressure in passage 151 is exhausted, to eliminate
unnecessary loading of the dog clutch DOG. With the above-stated valve configuration,
the main pressure in passage 118 is in fluid communication with clutches C1 and C6,
which will engage. The main pressure in passage 118 is communicated to the converter

GP-308704-PTA-DLT
20
flow valve 110 via passage 164 across trim valve 126 to passage 167. Clutches C4. and
C5 exhaust. Pressure switches SW2, SW4, SW5 and SW8 report a low logic state and
pressure switches SW1, SW3, SW6 and SW7 report a high logic state for diagnostic
purposes.
[0051] When operating in the second forward speed ratio range (2nd), the trim
valves 122, 126 and 128 are pressure-set and trim valves 120 and 130 are spring-set by
energizing solenoids PCS2. PCS4, PCS6, PCS1 and PCS7, respectively. If the second
forward speed ratio range is attained in a shift from the first alternate speed ratio range
(1st'), then the dog clutch actuator valve 144 remains in the forward position and the
logic valve Z in a pressure-set position due to the previous actuation of the dog clutch
actuator valve 144 in the first alternate forward speed ratio range (1st'). The remaining
trim valves 120 and 124 remain in a spring-set position. With the above-stated valve
configuration, clutches C2, TCC and C6 will be in an engaged position while clutches C4
and C5 exhaust. To effect engagement of clutch C2. pressurized fluid within passage 150
is communicated to outlet passage 152 of trim valve 122. To effect the engagement of
clutch C6. pressurized fluid within passage 158 is communicated to outlet passage 160 of
trim valve 128. Because they are in the spring-set position, logic valve X and logic valve
Y communicate the fluid within passage 118 to passage 158. To effect engagement of
clutch TCC. trim valve 126 is pressure-set by energizing solenoid valve PCS4. so that the
main pressure in passage 118 is communicated to the converter valve 1 10 via passage
164 across trim valve 126 to passage 167. Pressure switches SW3. SW4. SW5 and SW8
report a low logic state and pressure switches SW1, SW2, SW6 and SW7 report a high
logic state for diagnostic purposes.
[0052] When operating in the third forward speed ratio range (3rd), the trim
valves 124, 126 and 128 are pressure-set and trim valves 120 and 130 are spring-set by
energizing solenoids PCS3, PCS4, PCS6, PCS1 and PCS7, respectively. The dog clutch
actuator valve 144 remains in the forward position and the logic valve Z in a pressure-set
position due to the previous actuation of the dog clutch actuator valve 144 in the first
alternate forward speed ratio range (1st") or in the second forward speed ratio range
(2nd), as described above. The remaining trim valve 122 remains in a spring-set position.

GP-308704-PTA-DLT
21
With the above-stated valve configuration, clutches C3, TCC and C6 will be in an
engaged position while clutches C4 and C5 will exhaust. To effect engagement of clutch
C3. pressurized fluid from passage 118 within passage 154 is communicated to outlet
passage 156 of the trim valve 124 and through the pressure-set logic valve Z to clutch C3.
To effect engagement of clutch TCC. trim valve 126 is pressure-set by energizing
solenoid valve PCS4, so that the main pressure in passage 118 is communicated to the
converter valve 110 via passage 164 across trim valve 126 to passage 167. To effect
engagement of clutch C6, pressurized fluid within passage 158 is communicated to outlet
passage 160 of trim valve 128. Because they are in the spring-set position, logic valve X
and logic valve Y communicate the fluid within passage 1 18 to passage 158. Pressure
switches SW5 and SW8 report a low logic state and pressure switches SW1, SW2. SW3.
SW4. SW6 and SW7 report a high logic state for diagnostic purposes.
[0053] When operating in the alternate third forward speed ratio range (3rd'), the
trim valves 124, 126 and 128 are pressure-set and trim valves 120 and 130 are spring set
by energizing solenoids PCS3, PCS4, PCS6, PCS1 and PCS7. respectively, to cause
engagement of clutches C3. TCC and C6. as described above with respect to the third
forward speed ratio range (3rd). The dog clutch actuator valve 144 remains in the
forward position and the logic valve Z in a pressure-set position due to the previous
actuation of the dog clutch actuator valve 144 in the first alternate forward speed ratio
range (1st') or in the second forward speed ratio range (2nd), as described above.
Additionally, solenoid valve SS2 is energized to move the logic valve Y to a pressure-set
position, thus allowing main pressure from passage 118 in communication with passage
169 to flow across the logic valve Y to outlet passage 148, moving the plug valve 159 of
the dog clutch actuator valve 144 upward. Additionally, the shifting of logic valve Y
puts exhaust pressure rather then main pressure into communication with the switches
SW2 and SW1 at the trim valves 120 and 128, respectively. Pressure switches SW1.
SW2. SW5 and SW8 report a low logic state and pressure switches SW3, SW4. SW6 and
SW7 report a high logic state for diagnostic purposes.
[0054] When operating in the fourth forward speed ratio range (4th), trim valves
122, 126 and 128 are pressure-set and trim valves 120 and 130 are spring-set by

GP-308704-PTA-DLT
22
energizing solenoids PCS2, PCS4. PCS6, PCS1 and PCS7. respectively. The dog clutch
actuator valve 144 remains in the forward position and the logic valve Z in a pressure-set
position due to the previous actuation of the dog clutch actuator valve 144 in the first
alternate forward speed ratio range (1st') or in the second forward speed ratio range
(2nd), as described above. Solenoid valve SS2 is energized to place logic valve Y in a
pressure-set position. With the above-stated valve configuration, clutches C5, TCC and
C6 will be in an engaged position while clutches C2 and C4 will exhaust. Engagement of
the clutches TCC and C6 are as described above with respect to the third forward speed
ratio range (3rd). To effect engagement of clutch C5, solenoid PCS2 is energized to
move trim valve 122 to a pressure-set position. Pressurized fluid from passage 118 in
communication with passage 150 is communicated to outlet passage 152 across trim
valve 122 and then across the pressure-set logic valve Y into communication with clutch
C5. Pressure switches SW1, SW2, SW3, SW4, SW5 and SW8 report a low logic state
and pressure switches SW6 and SW7 report a high logic state for diagnostic purposes.
[0055] When operating in the fifth forward speed ratio range (5th). trim valves
120, 126 and 130 are pressure-set. Solenoid PCS4 is energized to pressure-set trim valve
126, but solenoids PCS1 and PCS7 are not energized to pressure-set trim valves 120 and
130, as these are normally open-type solenoid valves. The dog clutch actuator valve 144
remains in the forward position and the logic valve Z in a pressure-set position due to the
previous actuation of the dog clutch actuator valve 144 in the first alternate forward speed
ratio range (1st') or in the second forward speed ratio range (2nd), as described above.
Solenoid valve SS2 is energized to place logic valve Y in a pressure-set position. With
the above-stated valve configuration, clutches C1, TCC and C7 will be in an engaged
position while clutches C2 and C4 will exhaust. To effect engagement of clutch Cl,
pressurized fluid within passage 150 is communicated to outlet passage 162 of trim valve
120. With the logic valve X in the spring-set position, fluid in passage 162
communicates with the clutch C1 across the logic valve X. To effect the engagement of
clutch TCC, trim valve 126 is pressure-set by energizing solenoid valve PCS4. To effect
the engagement of clutch C7, pressurized fluid within passage 154 is communicated to
outlet passage 173 and across the pressure-set logic valve Z to the clutch C7. With the

GP-308704-PTA-DLT
23
logic valve Y in a pressure-set position, pressurized fluid in passage 152 can exhaust.
Pressure switches SW4 and SW8 report a low logic state and pressure switches SW1.
SW2, SW3, SW5, SW6 and SW7 report a high logic state for diagnostic purposes.
[0056] When operating in the alternate fifth forward speed ratio range (5th'). trim
valves 120, 126 and 130 are pressure-set, by energizing solenoid PCS4. but not solenoids
PCS1 or PCS7, as described above with respect to the fifth forward speed ratio range
(5th). The dog clutch actuator valve 144 remains in the forward position and the logic
valve Z in a pressure-set position due to the previous actuation of the dog clutch actuator
valve 144 in the first alternate forward speed ratio range (1st') or in the second forward
speed ratio range (2nd), as described above. With the above-stated valve configuration,
the clutches C1, TCC and C7 are engaged (as described above with respect to the fifth
forward speed ratio range (5th)) while the clutches C4 and C5 exhaust. Pressure switches
SW1, SW2, SW4 and SW8 report a low logic state and pressure switches SW3, SW5,
SW6 and SW7 report a high logic state for diagnostic purposes.
[0057] When operating in the sixth forward speed ratio range (6th). trim valves
122, 126 and 130 are pressure-set. Solenoids PCS2 and PCS4 are energized to pressure-
set trim valves C2 and TCC. respectively, but solenoid valve PCS7 is not energized, as it
is normally open. The dog clutch actuator valve 144 remains in the forward position and
the logic valve Z in a pressure-set position due to the previous actuation of the dog clutch
actuator valve 144 in the first alternate forward speed ratio range (1st') or in the second
forward speed ratio range (2nd), as described above. With the above-stated valve
configuration, clutches C2, TCC and C7 will engage while clutches C4 and C5 will
exhaust. To effect engagement of clutch C2. pressurized fluid within passage 150 is
communicated to outlet passage 152 of trim valve 122. The clutches TCC and C7 are
engaged as described above with respect to the fifth forward speed ratio range (5th).
Pressure switches SW1, SW3, SW4 and SW8 report a low logic state and pressure
switches SW2. SW5, SW6 and SW7 report a high logic state for diagnostic purposes.
[0058] When operating in the seventh forward speed ratio range (7th), trim valves
124. 126 and 130 are pressure-set. Solenoids PCS3 and PCS4 are energized to pressure-
set trim valves 124 and 126, respectively, but solenoid valve PCS7 is not energized, as it

GP-308704-PTA-DLT
24
is normally open. The dog clutch actuator valve 144 remains in the forward position and
the logic valve Z in a pressure-set position due to the previous actuation of the dog clutch
actuator valve 144 in the first alternate forward speed ratio range (1st') or in the second
forward speed ratio range (2nd), as described above. With the above-stated valve
configuration, clutches C3, TCC and C7 will engage while clutches C4 and C5 will
exhaust. To effect engagement of clutch C3, pressurized fluid from passage 118 within
passage 154 is communicated to outlet passage 156 of the trim valve 124 and through the
pressure-set logic valve Z to clutch C3. The clutches TCC and C7 are engaged as
described above with respect to the fifth forward speed ratio range (5th). Pressure
switches SW1 and SW8 report a low logic state and pressure switches SW2. SW3. SW4.
SW5, SW6 and SW7 report a high logic state for diagnostic purposes.
[0059] When operating in the seventh alternate forward speed ratio range (7th').
trim valves and solenoids are energized as described with respect to the seventh forward
speed ratio range (7th). except that solenoid valve SS2 is also energized to place the Y
valve into a pressure-set position, thus providing pressurized fluid to channel 148. control
pressure fluid to channel 175. and exhaust fluid to channel 171. causing the pressure at
switch SW2 in communication with trim valve 120 to be exhaust pressure and pressure at
switch SW1 in communication with trim valve 128 to be control pressure. Pressure
switches SW2 and SW8 report a low logic state and pressure switches SW1. SW3, SW4,
SW5. SW6 and SW7 report a high logic state for diagnostic purposes.
[0060] When operating in the seventh alternate forward speed ratio range (7th").
trim valves and solenoids are energized as described with respect to the seventh forward
speed ratio range (7th). except that solenoid valves SS1 and SS2 are also energized.
Energizing solenoid valve SS1 places logic valve X in a pressure-set position to allow
pressurized fluid from passage 143 to passage 146 and shifts the dog actuator clutch
valve 144 to a neutral position, while preventing the pressurized fluid in passage 143
from reaching passage 174. changing the monitored pressures at the switches SW3 and
SW4 associated with trim valves 122 and 124 from high pressure to low pressure and the
monitored pressure at the lower switch SW8 associated with the dog clutch actuator valve
144 from exhaust pressure to control pressure. With the dog clutch actuator valve 144 in

GP-308704-PTA-DLT
25
a neutral position, logic valve Z is in a pressure-set position. Solenoid valve SS2 is also
energized to place logic valve Y into a pressure-set position, thus providing pressurized
fluid to channel 148 and exhaust fluid to channel 171, causing the pressure at switch SW2
associated with trim valve 120 to be at exhaust pressure and pressure at switch SW1
associated with trim valve 128 to be at control pressure. Pressure switches SW2. SW3
and SW4 report a low logic state and pressure switches SW1, SW5, SW6. SW7 and SW8
report a high logic state for diagnostic purposes.
[0061] When operating in the seventh alternate forward speed ratio range (7th"').
trim valves and solenoids are energized as described with respect to the seventh forward
speed ratio range (7th). except that solenoid valves SS1, SS2 and SS3 are also energized.
Energizing solenoid valves SS1 and SS2 has the effects described above with respect to
speed ratio range (7th"). Energizing solenoid valve SS3 as well moves logic valve W to
a pressure-set position, thus exhausting fluid in channel 155. Pressure switches SW2 and
SW8 report a low logic state and pressure switches SW1, SW3, SW4, SW5, SW6 and
SW7 report a high logic state for diagnostic purposes.
[0062] When operating in the eighth forward speed ratio range (8th), trim valves
124. 126 and 130 are pressure-set. Solenoid valve PCS4 is energized to pressure-set trim
valve 126. but solenoid valves PCS1 and PCS7 are not. as these are normally open-type
solenoid valves. Solenoid valves SS1 and SS2 are also energized to move the logic
valves X and Y, respectively, to pressure-set positions, causing the dog clutch actuator
valve 144 to be in a neutral position. With logic valve X in a pressure-set position,
pressurized fluid from passage 143 is communicated to passage 146, while preventing the
pressurized fluid in passage 143 from reaching passage 174. causing the monitored
pressures at the switch SW3 associated with trim valve 122 to be at exhaust pressure, that
at the switch SW4 associated with trim valve 124 to be at control pressure, and that at the
lower switch SW8 associated with the dog clutch actuator valve 144 to be at control
pressure. With the dog clutch actuator valve 144 in a neutral position, logic valve Z is in
a pressure-set position.
[0063] With the above-stated valve configuration, clutches C4, TCC and C7 will
engage while clutches C1, C2 and C6 will exhaust. To effect engagement of clutch C4.

GP-308704-PTA-DLT
26
pressurized fluid from passage 150 crosses the pressure-set trim valve 120 to outlet
passage 162 and across pressure-set logic valve X into communication with clutch C4.
To effect the engagement of clutch TCC, trim valve 126 is pressure-set by energizing
solenoid valve PCS4. To effect engagement of clutch C7, pressurized fluid from passage
154 crosses pressure-set trim valve 130 to communicate with passage 173 and then
crosses pressure-set logic valve Z into communication with clutch C7. The pressure-set
position of logic valve X allows pressurized fluid to pass from passage 143 across the
pressure-set logic valve X to passage 146, shifting the dog clutch actuator valve 144 to a
neutral state or position, allowing control pressure fluid to contact the lower switch SW8
associated with the dog clutch actuator valve 144. Furthermore, the pressure-set position
of logic valve Y allows some of the pressurized fluid crossing logic valve X to be routed
to passage 148. Pressure switch SW3 reports a low logic state and pressure switches
SW1. SW2, SW4, SW5. SW6. SW7 and SW8 report a high logic state for diagnostic
purposes.
[0064] When operating in the ninth forward speed ratio range (9th), trim valves
122, 126 and 130 are pressure-set. Solenoid valves PCS2 and PCS4 are energized to
pressure-set trim valves 122 and 126, but solenoid valve PCS7 is not energized, as it is
normally-open type solenoid valve. Solenoid valves SS1 and SS2 are also energized so
that logic valves X and Y, respectively, are in pressure-set positions and the dog clutch
actuator valve 144 is in a neutral position. With the above-stated valve configuration,
clutches TCC and C7 will engage (as described above with respect to the eighth forward
speed ratio range (8th)) as well as clutch C5, while clutches C1, C2 and C6 will exhaust.
To effect engagement of clutch C5, pressurized fluid from forward 150 communicates
with outlet passage 152 across the pressure-set trim valve 122 and then with clutch C5
through the pressure-set logic valve Y. Because the control system 100 is designed with
the dog clutch actuator valve 144 in the neutral position in the higher speed ratio ranges
(the alternate seventh forward speed ratio ranges (7th") and (7th'")), as well as in the
eighth (8th) and ninth (9th) forward speed ratio ranges, spin losses are reduced in the
transmission 10 of Figure 1. Pressure switch SW2 reports a low logic state and pressure

GP-308704-PTA-DLT
27
switches SW1, SW3, SW4, SW5, SW6, SW7 and SW8 report a high logic state for
diagnostic purposes.
Multiplexing of Trim Systems
[0065] As is evident from the Figures and from the above description, the first
trim system, which includes solenoid valve PCS1 and trim valve 120, is multiplexed to
control engagement of clutches C1 and clutch C4. Shifting of the logic valve X between
a spring-set position and a pressure-set position determines which of the clutches C1 and
C4 will be engaged via the pressurized fluid fed through the pressure-set trim valve 120
and the logic valve X. As used herein, a valve is "multiplexed" when it has more than
one function, such as when it is able to at least partially control engagement of more than
one torque-transmitting mechanism.
[0066] Furthermore the second trim system, which includes solenoid valve PCS2
and trim valve 124 is multiplexed to control engagement of clutches C2 and C5. Shifting
of logic valve Y between a spring-set position and a pressure-set position determines
which of the clutches C2 and C5 will be engaged via pressurized fluid fed through the
pressure-set trim valve 124 to the logic valve Y.
[0067] Still further, the third trim system, which includes the solenoid valve
PCS3 and the trim valve 124 is multiplexed to control engagement of the C3 and C7
clutches, at least in speed ratio ranges (R2), (R1). startup, neutral, and first forward speed
ratio range (1 st). In speed ratio ranges above the first forward speed ratio range (1st).
engagement of clutch C7 is controlled by the sixth trim system, which includes solenoid
valve PCS7 and trim valve 130. Shifting of logic valve Z between a spring-set position
and a pressure-set position determines which of the clutches C3 and C7 will be engaged
via pressurized fluid fed through the pressure-set trim valve 124 to the logic valve Z. The
shifting of logic valve Z is controlled by the position of the dog clutch actuator valve 144,
which in turn is controlled by the positions of the logic valves X and Y and by solenoid
valve SS3.
Double Transition Shifts and Skip Shifts
[0068] As is evident from Figure 3 and from the above description, a shift from
the fourth forward speed ratio range (4th) to the fifth forward speed ratio range (5th)

GP-308704-PTA-DLT
28
involves a tour clutch, double transition shift. That is, clutches C5 and C6 are disengaged
while clutches C1 and C7 are engaged. Thus, even with the multiplexing of the trim
systems, this four clutch shift is achieved by the control system 100. A four clutch,
double transition shift is also realized. As is evident from Figure 3, numerous other shifts
also involve double transition shifts (i.e., a shift that requires that more than one clutch be
engaged or disengaged). The system 100 is also able to accomplish many skip shifts,
including a shift from the first reverse speed ratio range (R1) to the first forward speed
ratio range (1st); a shift from the second reverse speed ratio range (R2) to the first
forward speed ratio range (1st); a shift from the first alternative forward speed ratio range
(1st") to the third forward speed ratio range (3rd); a shift from the third forward speed
ratio range (3rd) to the fifth forward speed ratio range (5th); a shift from the fifth forward
speed ratio range (5th) to the seventh forward speed ratio range (7th); and a shift from the
second alternative seventh forward speed ratio range (7th") to the ninth forward speed
ratio range (9th).
Logic Valves Used to Control Power Off/ Drive-Home Modes
[0069] The hydraulic control system 100 is configured to provide a functional
"drive-home" system in the event of an interruption or failure in electrical power, which
would prevent selective energizing of the solenoid valves. The hydraulic control system
100 is designed to default to two different speed ratio ranges (referred to as failure
modes), i.e.. there are two different failure modes, depending on which speed ratio range
the system 100 is providing when failure occurs. Specifically, if power failure occurs
while the transmission 10 is operating in any of the first reverse speed ratio range (Rl),
the second reverse speed ratio range (R2) or is in neutral (N), the hydraulic control
system 100 will automatically operate in a neutral state (i.e.. an operating condition
which will not allow driving the vehicle in either forward or reverse). This "failure" to a
neutral state occurs for several reasons. First, in each of the first reverse speed ratio
range (R1), the second reverse speed ratio range (R2) or the neutral (N) speed ratio range,
the dog clutch actuator valve 144 is in a reverse position during normal operation (i.e..
when electrical energy is available). Additionally, because solenoid valve PCS1 is a
normally open-type valve, trim valve 120 will be pressure-set in the absence of an

GP-308704-PTA-DLT
29
energizing control signal. This causes the pressurized fluid in passage 150 to
communicate with outlet passage 162 and be directed through the logic valve X (which
allows flow to clutch C1 when in the spring-set position) to clutch C1. Because the trim
valves 122, 124. 128 and 130 and the logic valves Z and Y are in spring-set positions
during a power failure with the dog clutch actuator valve 144 in a reverse position, trim
valve 128 does not allow pressurized fluid flow to clutch C6. logic valve Z does not
allow pressurized fluid flow to clutches C3 and C7, and logic valve Y does not allow
pressurized fluid flow to clutches C2 and C5. With only clutch C1 engaged, the
transmission 10 of Figure 1 operates in a neutral state.
[0070] If power failure occurs when the transmission 10 is in any of the speed
ratio ranges (1st), (1st'), (2nd), (3rd), (3rd'), 4th), (5th), (5th'), (6th). (7th). and (7th').
referred to herein as "low" speed ratio ranges, the hydraulic control system 100 will
automatically operate in the fifth forward speed ratio range (5th). This "failure" to the
fifth forward speed ratio range (5th) occurs for several reasons. First, in each of the first
forward speed ratio range (1st) through the seventh alternate forward speed ratio range
(7th'), the dog clutch actuator valve 144 is in a forward position during normal operation
(i.e., when electrical energy is available), causing logic valve Z to be pressure-set.
Additionally, because solenoid valve PCS1 is a normally open-type valve, trim valve 120
will be pressure-set in the absence of an energizing control signal. This causes the
pressurized fluid in passage 150 to communicate with outlet passage 162 and be directed
through the logic valve X (which allows flow to clutch C1 when in the spring-set
position) to clutch C1. Solenoid valve PCS7 is also a normally-open type solenoid valve,
so trim valve 130 will be pressure-set in the absence of an electrical control signal and
will provide pressurized fluid from passage 154 to outlet passage 173 and through the
pressure-set logic valve Z to clutch C7. Because the trim valves 120, 124. and 128 and
the logic valves X and Y are in spring-set positions during a power failure with the dog
clutch actuator valve 144 in a reverse position, trim valve 128 does not allow pressurized
fluid flow to clutch C6, and logic valve Y does not allow pressurized fluid flow to
clutches C2 and C5. With only clutches C1 and C75 engaged, the transmission 10 of

GP-308704-PTA-DLT
30
Figure 1 operates in the fifth forward speed ratio range, except without engagement of the
torque-converter clutch TCC.
[0071] If power failure occurs when the transmission 10 is in any of the speed
ratio ranges (7th"), (7th'"). (8th). or (9th). referred to herein as "high" speed ratio
ranges, the hydraulic control system 100 will automatically operate in the eighth forward
speed ratio range (8th). This "failure" to the eighth forward speed ratio range (8th)
occurs for several reasons. First, in each of the alternate seventh forward speed ratio
range (7th") through the ninth forward speed ratio range (9th). the dog clutch actuator
valve 144 is in a neutral position during normal operation (i.e., when electrical energy is
available), causing logic valve Z to be pressure-set. When power is interrupted, the
neutral position of the dog clutch actuator valve 144 causes logic valves X and Y to
remain pressure-set (i.e., the dog clutch actuator valve 144 latches the logic valves X and
Y), as they are in each of the alternate seventh forward speed ratio range (7th") through
the ninth forward speed ratio range (9th), even though solenoid valves SS1 and SS2 are
not energized, because there are no exhaust routes open for the pressurized fluid in
passages 146 and 148 acting on logic valves X and Y, and for the controlled pressure
fluid acting on logic valves X and Y through the spring-set logic valve W which
communicates passage 153 with passage 155. During normal operation, the solenoid SS3
can be energized to place logic valve W in a pressure-set position (either in steady state,
or temporarily) to prevent fluid communication between passages 153 and 155. thus
preventing the dog clutch actuator 144 from having a latching effect on logic valves X
and Y.
[0072] The logic valves X and Y also function to "lock out" clutch C6 during
forward ratio ranges (7th"). (7th"'), (8th) and (9th). This occurs because, in these
operating ranges, the logic valves X and Y are both in pressure-set positions. Thus, logic
valve X and logic valve Y prevent pressurized fluid from passage 118 from reaching
passage 158, while logic valve Y allows control pressure fluid from passage 117 to
passage 179, preventing trim valve 128 from being placed in a pressure-set position by
solenoid valve PCS6.

GP-308704-PTA-DLT
31
[0073] While the best modes for carrying out the invention have been described
in detail, those familiar with the art to which this invention relates will recognize various
alternative designs and embodiments for practicing the invention within the scope of the
appended claims.

GP-308704-PTA-DLT
32
CLAIMS
1. An electro-hydraulic control system that controls engagement of
torque-transmitting mechanisms in a transmission; wherein the control system includes a
controller, comprising:
a pressure switch diagnostic system having first, second, third and fourth
pressure switches each having a high and a low logic state:
first and second logic valves each movable between a respective first
position and second position;
first, second, third and fourth trim valves each movable between a
respective first position and second position;
wherein two of the pressure switches are each multiplexed to report one of
the high logic state and the low logic state to the controller in accordance with a relatively
high and a relatively low fluid pressure, respectively, at a respective one of two of the
trim valves corresponding with the position of the respective one of two of the trim
valves and the position of the first logic valve; thereby enabling a determination of a
change in position or a failure to change position of the respective one of two of the trim
valves or the first logic valve; and
wherein the other two of the pressure switches are each multiplexed to
report one of the high and the low logic state to the controller in accordance with a
relatively high and a relatively low fluid pressure, respectively, at a respective one of the
other two trim valves corresponding with the position of the respective one of the other
two trim valves and the position of the second logic valve; thereby enabling a
determination of a change in position or a failure to change position of the respective one
of the other two trim valves or of the second logic valve.
2. The electro-hydraulic control system of claim 1, wherein the
diagnostic system is characterized by an absence of any other pressure switches used to
monitor the position of the four trim valves and the two logic valves.

GP-308704-PTA-DLT
3. The electro-hydraulic control system of claim 1. wherein the
torque-transmitting mechanisms include a dog clutch selectively movable between a
reverse, a neutral and a forward position, and further comprising:
a dog clutch actuator valve selectively movable between three different
positions corresponding with and controlling the reverse, neutral and forward positions of
the dog clutch;
wherein the diagnostic system further includes:
fifth and sixth pressure switches each having a high and a low
logic state and in fluid communication with the dog clutch actuator valve at a different
respective location, and each operable to report one of the high and the low logic state to
the controller in accordance with a relatively high and a relatively low fluid pressure,
respectively, corresponding with the position of the dog clutch actuator valve.
4. The electro-hydraulic control system of claim 3. wherein the
diagnostic system is characterized by an absence of any other pressure switches used to
monitor the position of the dog clutch actuator valve.
5. The electro-hydraulic control system of claim 3, further
comprising:
a fifth trim valve;
a third logic valve;
wherein the diagnostic system further includes:
a seventh pressure switch in fluid communication with the fifth
trim valve, and operable to report one of the high and the low logic state to the controller
in accordance with a relatively high and a relatively low fluid pressure, respectively,
corresponding with the position of the fifth trim valve, thereby enabling a determination
of a change in position or a failure to change position of the fifth trim valve; and

GP-308704-PTA-DLT
34
an eighth pressure switch in fluid communication with the third
logic valve, and operable to report one of the high and the low logic state to the controller
in accordance with a relatively high and a relatively low fluid pressure, respectively.
corresponding with the position of the third logic valve, thereby enabling a determination
of a change in position or a failure to change position of the third logic valve.
6. The electro-hydraulic control system of claim 5. wherein the
diagnostic system is characterized by an absence of any other pressure switches used to
monitor the position of the five trim valves, the dog clutch actuator valve and the three
logic valves.
7. The electro-hydraulic control system of claim 5. wherein the trim
valves are solenoid operated pressure regulated valves.
8. The electro-hydraulic control system of claim 5, in combination
with the transmission, wherein the torque-transmitting mechanisms include seven torque-
transmitting mechanisms and the dog clutch, and are selectively engagable in different
combinations to provide at least nine forward speed ratios and two reverse speed ratios;
and wherein the transmission is a countershaft transmission.
9. An electro-hydraulic control system comprising:
five trim valves;
three logic valves;
wherein each of the trim valves and logic valves is selectively movable
between respective first and second positions;
a three position dog-clutch actuator valve selectively movable between
reverse, neutral and forward positions;
a diagnostic system including eight pressure switches in signal
communication with a controller, each operable to report a logic state to the controller

GP-308704-PTA-DLT
35
indicative of a position of at least one of the trim valves, the logic valve and the dog
clutch actuator valve: and wherein some of the pressure switches are multiplexed in
selective fluid communication with more than one of the trim valves, the logic valve and
the dog clutch actuator valve to report logic states indicative of the positions of more than
one valve.
10. The electro-hydraulic control system of claim 9, wherein a first
and a second of the pressure switches are each multiplexed with a first of the logic valves
with a respective one of a first and a second of the trim valves.
11. The electro-hydraulic control system of claim 10. wherein a third
and a fourth of the pressure switches are each multiplexed with a second of the logic
valves and with a respective one of a third and a fourth of the trim valves.
12. The electro-hydraulic control system of claim 9. wherein two of
the pressure switches are in fluid communication with the dog clutch actuator valve;
wherein the combined logic states of the two pressure switches in fluid communication
with the dog clutch actuator valve are indicative of the position of the dog clutch actuator
valve.
13. The electro-hydraulic control system of claim 9 in combination
with a transmission operable in multiple speed ratios; and wherein the controller is
operable to determine whether the reported logic states of the pressure switches are
consistent with expected logic states corresponding with the speed ratio commanded by
the controller.
14. An electro-hydraulic control system in combination with a
transmission comprising:
five trim valves:

GP-308704-PTA-DLT
36
three logic valves;
wherein each of the trim valves and logic valves is selectively movable
between respective first and second positions;
a three position dog-clutch actuator valve selectively movable between
reverse, neutral and forward positions;
a diagnostic system including eight pressure switches in signal
communication with a controller, each operable to report a logic state to the controller
indicative of a position of at least one of the trim valves, the logic valve and the dog
clutch actuator valve; and wherein some of the pressure switches are multiplexed in
selective fluid communication with more than one of the trim valves, the logic valve and
the dog clutch actuator valve to thereby be operable to report logic states indicative of the
positions of more than one of the valves; and
wherein the torque-transmitting mechanisms include seven torque-
transmitting mechanisms and the dog clutch selectively engagable in different
combinations to provide at least nine forward speed ratios and two reverse speed ratios;
and wherein the transmission is a countershaft transmission.

An electro-hydraulic control system is provided, preferably for a
countershaft transmission, with a diagnostic system that uses extensive multiplexing of
pressure switches to provide accurate information regarding the position of valves within
the control system while minimizing the number of required components.

Documents:

01501-kol-2007-abstract.pdf

01501-kol-2007-claims.pdf

01501-kol-2007-correspondence others.pdf

01501-kol-2007-description complete.pdf

01501-kol-2007-drawings.pdf

01501-kol-2007-form 1.pdf

01501-kol-2007-form 2.pdf

01501-kol-2007-form 3.pdf

01501-kol-2007-form 5.pdf

01501-kol-2007-translated copy of priority document.pdf

1501-KOL-2007-(07-02-2012)-ABSTRACT.pdf

1501-KOL-2007-(07-02-2012)-CLAIMS.pdf

1501-KOL-2007-(07-02-2012)-CORRESPONDENCE.pdf

1501-KOL-2007-(07-02-2012)-DESCRIPTION (COMPLETE).pdf

1501-KOL-2007-(07-02-2012)-DRAWINGS.pdf

1501-KOL-2007-(07-02-2012)-FORM-1.pdf

1501-KOL-2007-(07-02-2012)-FORM-13-1.pdf

1501-KOL-2007-(07-02-2012)-FORM-13.pdf

1501-KOL-2007-(07-02-2012)-FORM-2.pdf

1501-KOL-2007-(07-02-2012)-FORM-3.pdf

1501-KOL-2007-ABSTRACT.pdf

1501-KOL-2007-AMANDED CLAIMS.pdf

1501-KOL-2007-AMANDED PAGES OF SPECIFICATION.pdf

1501-KOL-2007-ASSIGNMENT 1.1.pdf

1501-KOL-2007-ASSIGNMENT.pdf

1501-KOL-2007-CORRESPONDENCE 1.1.pdf

1501-kol-2007-CORRESPONDENCE OTHERS 1.1.pdf

1501-KOL-2007-CORRESPONDENCE OTHERS 1.2.pdf

1501-KOL-2007-CORRESPONDENCE.pdf

1501-KOL-2007-DESCRIPTION (COMPLETE).pdf

1501-KOL-2007-DRAWINGS.pdf

1501-KOL-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

1501-KOL-2007-EXAMINATION REPORT.pdf

1501-KOL-2007-FORM 1-1.1.pdf

1501-KOL-2007-FORM 1-1.2.pdf

1501-KOL-2007-FORM 1.pdf

1501-KOL-2007-FORM 13.pdf

1501-kol-2007-FORM 18.pdf

1501-KOL-2007-FORM 2-1.1.pdf

1501-KOL-2007-FORM 2-1.2.pdf

1501-KOL-2007-FORM 3 1.1.pdf

1501-KOL-2007-FORM 3.pdf

1501-KOL-2007-FORM 5.pdf

1501-KOL-2007-FORM 6-1.1.pdf

1501-KOL-2007-FORM 6.pdf

1501-KOL-2007-GPA.pdf

1501-KOL-2007-GRANTED-ABSTRACT.pdf

1501-KOL-2007-GRANTED-CLAIMS.pdf

1501-KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

1501-KOL-2007-GRANTED-DRAWINGS.pdf

1501-KOL-2007-GRANTED-FORM 1.pdf

1501-KOL-2007-GRANTED-FORM 2.pdf

1501-KOL-2007-GRANTED-LETTER PATENT.pdf

1501-KOL-2007-GRANTED-SPECIFICATION.pdf

1501-KOL-2007-OTHERS 1.1.pdf

1501-KOL-2007-OTHERS.pdf

1501-KOL-2007-PA.pdf

1501-KOL-2007-PETITION UNDER RULE 137-1.1.pdf

1501-KOL-2007-PETITION UNDER RULE 137.pdf

1501-KOL-2007-PRIORITY DOCUMENT.pdf

1501-KOL-2007-REPLY TO EXAMINATION REPORT.pdf


Patent Number 253543
Indian Patent Application Number 1501/KOL/2007
PG Journal Number 31/2012
Publication Date 03-Aug-2012
Grant Date 30-Jul-2012
Date of Filing 01-Nov-2007
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS INC
Applicant Address 300 RENAISSANCE CENTER,DETROIT, MICHIGAN 48265-3000, U.S.A
Inventors:
# Inventor's Name Inventor's Address
1 CHARLES F. LONG 237 FAWN COURT, PITTSBORO, INDIANA 46167
2 BRYAN H. HAGELSKAMP 12965 CANTIGNY WAY, CARMEL INDIANA 46033
PCT International Classification Number F16H61/00; F16H61/12; F16H61/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/626524 2007-01-24 U.S.A.