Title of Invention

AN IMPROVED TRANSMISSION PROVIDING MULTIPLE FORWARD SPEED RATIO AND ONE REVERSE SPEED RATIO

Abstract The transmission (14) has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission (14) comprises three planetary gear sets (20,30,40) having six torque-transmitting mechanisms (50,52,54,56,58,60) and two fixed interconnections (70,72). The powertrain (10) comprises an engine and torque converter (12) that is continuously connected to one of the planetary gear members and an output member (19) that is continuously connected with another one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, the transmission housing (60) and with the input member (17), and are operated in combinations of three to establish eight forward speed ratios and one reverse speed ratio.
Full Text

FIELD OF THE INVENTION
The present invention relates to a power transmission having three planetary gear sets
that are controlled by six torque-transmitting devices to provide eight forward speed
ratios and one reverse speed ratio.
BACKGROUND OF THE INVENTION
Passenger vehicles include a powertrain that is comprised of an engine, multi-speed
transmission, and a differential or final drive. The multi-speed transmission increases the
overall operating range of the vehicle by permitting the engine to operate through its
torque range a number of times. The number of forward speed ratios that are available
in the transmission determines the number of times the engine torque range is
repeated. Early automatic transmissions had two speed ranges. This severely limited the
overall speed range of the vehicle and therefore required a relatively large engine that
could produce a wide speed and torque range. This resulted in the engine operating at a
specific fuel consumption point during cruising, other than the most efficient point.
Therefore, manually-shifted (countershaft transmissions) were the most popular.
With the advent of three- and four-speed automatic transmissions, the automatic
shifting (planetary gear) transmission increased in popularity with the motoring public.
These transmissions improved the operating performance and fuel economy of the
vehicle. The increased number of speed ratios reduces the step size between ratios and
therefore improves the shift quality of the transmission by making the ratio interchanges
substantially imperceptible to the operator under normal vehicle acceleration.
Six-speed transmissions offer several advantages over four- and five-speed
transmissions, including improved vehicle acceleration and improved fuel economy.
While many trucks employ power transmissions having six or more forward speed ratios,
passenger

cars are still manufactured with three- and four-speed automatic transmissions
and relatively few five or six-speed devices due to the size and complexity of
these transmissions.
Seven-, eight- and nine-speed transmissions provide further improvements in
acceleration and fuel economy over six-speed transmissions. However, like the
six-speed transmissions discussed above, the development of seven-, eight- and
nine-speed transmissions has been precluded because of complexity, size and
cost.
US6648789 teaches a multi-speed transmission with three interconnected
planetary gear sets. The transmission has a plurality of members that can be
utilized in powertrains to provide at least seven forward speed ratios and one
reverse speed ratio. The transmission family members comprise three planetary
gear sets and six torque-transmitting mechanisms. A fixed interconnection
continuously connects members of the first, second and third planetary gear
sets. The powertrain comprises an engine and torque converter that is
continuously connected to one of the planetary gear members and an output
member that is continuously connected with another one of the planetary gear
members. The six torque-transmitting mechanisms provide interconnections
between various gear members, the input shaft, the output shaft, and with the
transmission housing, and are operated in combinations of three to establish at
least seven forward speed ratios and one reverse speed ratio.
US 7090610 discloses wide ratio transmissions with three interconnected
planetary gear sets. The family of transmissions has a plurality of members that
can be utilized in powertrains to provide at least eight forward speed ratios and

one reverse speed ratio. The transmission family members include three
planetary gear sets having seven torque-transmitting mechanisms and three
fixed interconnections. The powertrain comprises an engine and torque converter
that is continuously connected to at least one of the planetary gear members
and an output member that is continuously connected with another one of the
planetary gear members. The seven torque-transmitting mechanisms provide
interconnections between various gear members, the input shaft, the output
shaft, and the transmission housing, and are operated in combinations of two to
establish at least eight forward speed ratios and at least one reverse speed ratio.
OBJECT OF THE INVENTION
It is an object of the present invention to provide an improved transmission
having three planetary gear sets controlled to provide eight forward speed ratios
and one reverse speed ratio.
SUMMARY OF THE INVENTION
The transmission family of the present invention has three planetary gear sets,
each of which includes a first, second and third member, which members may
comprise a sun gear, a ring gear, or a planet carrier assembly member, in any
order.
In referring to the first, second and third gear sets in this description and in the
claims, these sets may be counted "first" to "third" in any order in the drawing
(i.e., left to right, right to left, etc.). Additionally, the first, second or third
members of each gear set may be counted "first" to "third" in any order in the
drawing (i.e., top to bottom, bottom to top, etc.) for each gear set.

Each carrier member can be either a single-pinion carrier member (simple) or a
double-pinion carrier member (compound). Embodiments with long pinions are
also possible.
A first interconnecting member continuously connects the third member of the
first planetary gear set with the third member of the second planetary gear set.
A second interconnecting member continuously connects the second member of
the second planetary gear set with the first member of the third planetary gear
set.
A first torque transmitting device, such a brake, selectively connects the first
member of the first planetary gear set with a stationary member (transmission
housing/casing).

A second torque transmitting device, such as a brake, selectively connects the
third member of the second planetary gear set with a stationary member (transmission
housing/casing).
A third torque transmitting device, such as a brake, selectively connects the
second member of the second planetary gear set with a stationary member (transmission
housing/casing).
A fourth torque transmitting device, such as a clutch, selectively connects the
second member of the first planetary gear set with the second member of the second planetary
gear set.
A fifth torque transmitting device, such as a clutch, selectively connects the
second member of the first planetary gear set with the second member of the third planetary
gear set.
A sixth torque transmitting device, such as a clutch, selectively connects the
first member of the second planetary gear set with the second member of the third planetary
gear set.
The six torque-transmitting mechanisms are selectively engageable in
combinations of three to yield eight forward speed ratios and one reverse speed ratio.
A variety of speed ratios and ratio spreads can be realized by suitably selecting
the tooth ratios of the planetary gear sets.
The above features and other features and advantages of the present invention
are readily apparent from the following detailed description of the best modes for carrying out
the invention when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

FIGURE 1a is a schematic representation of a powertrain including a planetary
transmission in accordance with the present invention; and

FIGURE lb is a truth table and chart depicting some of the operating
characteristics of the powertrain shown in Figure la.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, there is shown in Figure la a powertrain 10 having a
conventional engine and torque converter 12, a planetary transmission 14, and a conventional
final drive mechanism 16. The engine 12 may be powered using various types of fuel to
improve the efficiency and fuel economy of a particular application. Such fuels may include,
for example, gasoline; diesel; ethanol; dimethyl ether; etc.
The planetary transmission 14 includes an input member 17 continuously
connected with the engine 12, a planetary gear arrangement 18, and an output member 19
continuously connected with the final drive mechanism 16. The planetary gear arrangement 18
includes three planetary gear sets 20, 30 and 40.
The planetary gear set 20 includes a sun gear member 22, a ring gear member
24, and a planet carrier assembly member 26. The planet carrier assembly member 26
includes a plurality of pinion gears 27 rotatably mounted on a carrier member 29 and disposed
in meshing relationship with both the sun gear member 22 and the ring gear member 24.
The planetary gear set 30 includes a sun gear member 32, a ring gear member
34, and a planet carrier assembly member 36. The planet carrier assembly member 36
includes a plurality of pinion gears 37 rotatably mounted on a carrier member 39 and disposed
in meshing relationship with both the ring gear member 34 and the sun gear member 32.
The planetary gear set 40 includes a sun gear member 42, a ring gear member
44, and a planet carrier assembly member 46. The planet carrier assembly member 46
includes a plurality of pinion gears 47 mounted on a carrier member 49 and disposed in
meshing relationship with both the ring gear member 44 and the sun gear member 42.
The planetary gear arrangement also includes six torque-transmitting
mechanisms 50, 52, 54, 55, 56 and 57. The torque-transmitting mechanisms 50, 52 and 54

are a stationary-type torque-transmitting mechanism, commonly termed brakes or reaction
clutches. The torque-transmitting mechanisms 55, 56 and 57 are rotating-type torque-
transmitting mechanisms, commonly termed clutches.
The input member 17 is continuously connected with the sun gear member 32 of
the planetary gear set 30. The output member 19 is continuously connected with the ring gear
member 44 of the planetary gear set 40. The first interconnecting member 70 continuously
connects the ring gear member 24 of the planetary gear set 20 with the ring gear member 34 of
the planetary gear set 30. The second interconnecting member 72 continuously connects the
planet carrier assembly member 36 of the planetary gear set 30 with the sun gear member 42
of the planetary gear set 40.
A first torque transmitting device, such as brake 50, selectively connects the sun
gear member 22 of the planetary gear set 20 with the transmission housing 60. A second
torque transmitting device, such as brake 52, selectively connects the ring gear member 34 of
the planetary gear set 30 with the transmission housing 60. A third torque transmitting device,
such as brake 54, selectively connects the planet carrier assembly member 36 of the planetary
gear set 30 with the transmission housing 60. A fourth torque transmitting device, such as
clutch 55, selectively connects the planet carrier assembly member 26 of the planetary gear set
20 with the planet carrier assembly member 36 of the planetary gear set 30. A fifth torque
transmitting device, such as clutch 56, selectively connects the planet carrier assembly member
26 of the planetary gear set 20 with the planet carrier assembly member 46 of the planetary
gear set 40. A sixth torque transmitting device, such as clutch 57, selectively connects the sun
gear member 32 of the planetary gear set 30 with the planet carrier assembly member 46 of the
planetary gear set 40.
As shown in Figure lb, and in particular the truth table disclosed therein, the
torque-transmitting mechanisms are selectively engaged in combinations of three to provide
eight forward speed ratios and one reverse speed ratio all with single transition shifts with a
double overdrive.

The reverse speed ratio is established with the engagement of the brake 52 and
clutches 55, 56. The brake 52 engages the ring gear member 34 and the ring gear member 24
via interconnecting member 70 with the transmission housing 60. The clutch 55 engages the
planet carrier assembly member 26 with the planet carrier assembly member 36 and the sun
gear member 42 via interconnecting member 72. The clutch 56 engages the planet carrier
assembly member 26 with the planet carrier assembly member 46. The sun gear member 32
rotates at the same speed as the input member 17. The ring gear member 34 and ring gear
member 24 do not rotate. The planet carrier assembly member 36, planet carrier assembly
member 26, planetary gear set 40 and output member 19 rotate at the same speed. The speed
of the planet carrier assembly member 36, and therefore the output member 19, is determined
from the speed of the sun gear member 32 and the ring gear/sun gear tooth ratio of the
planetary gear set 30. The numerical value of the reverse speed ratio is determined utilizing the
ring gear/sun gear tooth ratios of the planetary gear set 30.
The first forward speed ratio is established with the engagement of the brakes 50,
52 and the clutch 56. The brake 50 engages the sun gear member 22 with the transmission
housing 60. The brake 52 engages the ring gear member 34 and the ring gear member 24 via
interconnecting member 70 with the transmission housing 60. The clutch 56 engages the planet
carrier assembly member 26 with the planet carrier assembly member 46. The sun gear member
32 rotates at the same speed as the input member 17. The ring gear member 34, planetary gear
set 20 and planet carrier assembly member 46 do not rotate. The planet carrier assembly member
36 and sun gear member 42 rotate at the same speed. The speed of the planet carrier assembly
member 36 is determined from the speed of the sun gear member 32 and the ring gear/sun gear
tooth ratio of the planetary gear set 30. The ring gear member 44 and output member 19 rotate at
the same speed. The speed of the ring gear member 44, and therefore the output member 19, is
determined from the speed of the sun gear member 42 and the ring gear/sun gear tooth ratio of
the planetary gear set 40. The numerical value of the first forward speed ratio is determined
utilizing the ring gear/sun gear tooth ratios of the planetary gear sets 30 and 40.

The second forward speed ratio is established with the engagement of the brakes
50, 54 and clutch 56. The brake 50 engages the sun gear member 22 with the transmission
housing 60. The brake 54 engages the planet carrier assembly member 36 and the sun gear
member 42 via interconnecting member 72 with the transmission housing 60. The clutch 56
engages the planet carrier assembly member 26 with the planet carrier assembly member 46.
The sun gear member 32 rotates at the same speed as the input member 17. The planet carrier
assembly member 36 and sun gear member 42 do not rotate. The ring gear member 34 and ring
gear member 24 rotate at the same speed. The speed of the ring gear member 34 is determined
from the speed of the sun gear member 32 and the ring gear/sun gear tooth ratio of the planetary
gear set 30. The sun gear member 22 does not rotate. The planet carrier assembly member 26
and planet carrier assembly member 46 rotate at the same speed. The speed of the planet carrier
assembly member 26 is determined from the speed of the ring gear member 24 and the ring
gear/sun gear tooth ratio of the planetary gear set 20. The ring gear member 44 and output
member 19 rotate at the same speed. The speed of the ring gear member 44, and therefore the
output member 19, is determined from the speed of the planet carrier assembly member 46 and
the ring gear/sun gear tooth ratio of the planetary gear set 40. The numerical value of the second
forward speed ratio is determined utilizing the ring gear/sun gear tooth ratios of the planetary
gear sets 20, 30 and 40.
The third forward speed ratio is established with the engagement of the brake 50
and the clutches 55, 56. The brake 50 engages the sun gear member 22 with the transmission
housing 60. The clutch 55 engages the planet carrier assembly member 26 with the planet carrier
assembly member 36 and the sun gear member 42 via interconnecting member 72. The clutch
56 engages the planet carrier assembly member 26 with the planet carrier assembly member 46.
The sun gear member 32 rotates at the same speed as the input member 17. The ring gear
member 34 and ring gear member 24 rotate at the same speed. The planet carrier assembly
member 36, planet carrier assembly member 26, planetary gear set 40 and output member 19
rotate at the same speed. The speed of the ring gear member 34 is determined from the speed of
the sun gear member 32, the speed of the planet carrier assembly member 36 and the ring

gear/sun gear tooth ratio of the planetary gear set 30. The speed of the planet carrier assembly
member 26, and therefore the output member 19, is determined from the speed of the ring gear
member 24 and the ring gear/sun gear tooth ratio of the planetary gear set 20. The numerical
value of the third forward speed ratio is determined utilizing the ring gear/sun gear tooth ratios of
the planetary gear sets 20 and 30.
The fourth forward speed ratio is established with the engagement of the brake 50
and the clutches 56, 57. The brake 50 engages the sun gear member 22 with the transmission
housing 60. The clutch 56 engages the planet carrier assembly member 26 with the planet carrier
member 46. The clutch 57 engages the sun gear member 32 with the planet carrier assembly
member 46. The sun gear member 32, planet carrier assembly member 46 and planet carrier
assembly member 26 via interconnecting member 72 rotate at the same speed as the input
member 17. The planet carrier assembly member 36 and sun gear member 42 rotate at the same
speed. The ring gear member 34 and ring gear member 24 rotate at the same speed. The speed
of the ring gear member 34 is determined from the speed of the sun gear member 32, the speed
of the planet carrier assembly member 36 and the ring gear/sun gear tooth ratio of the planetary
gear set 30. The sun gear member 22 does not rotate. The speed of the planet carrier assembly
member 26 is determined from the speed of the ring gear member 24 and the ring gear/sun gear
tooth ratio of the planetary gear set 20. The ring gear member 44 and the output member 19
rotate at the same speed. The speed of the ring gear member 44, and therefore the output
member 19, is determined from the speed of the sun gear member 42, the speed of the planet
carrier assembly member 46 and the ring gear/sun gear tooth ratio of the planetary gear set 40.
The numerical value of the fourth forward speed ratio is determined utilizing the ring gear/sun
gear tooth ratios of the planetary gear sets 20, 30 and 40.
The fifth forward speed ratio is established with the engagement of the clutches
55, 56, 57. In this configuration, the input member 17 is directly connected with the output
member 19. The numerical value of the fifth forward speed ratio is 1.
The sixth forward speed ratio is established with the engagement of the brake 50
and the clutches 55,57. The brake 50 engages the sun gear member 22 with the transmission

housing 60. The clutch 55 engages the planet carrier assembly member 26 with the planet carrier
assembly member 36 and with the sun gear member 42 via interconnecting member 72. The
clutch 57 engages the sun gear member 32 with the planet carrier assembly member 46. The sun
gear member 32 and planet carrier assembly member 46 rotate at the same speed as the input
member 17. The planet carrier assembly member 26, planet carrier assembly member 36 and
sun gear member 42 rotate at the same speed. The ring gear member 34 and ring gear member
24 rotate at the same speed. The speed of the ring gear member 34 is determined from the speed
of the sun gear member 32, the speed of the planet carrier assembly member 36 and the ring
gear/sun gear tooth ratio of the planetary gear set 30. The sun gear member 22 does not rotate.
The speed of the planet carrier assembly member 26 is determined from the speed of the ring
gear member 24 and the ring gear/sun gear tooth ratio of the planetary gear set 20. The ring gear
member 44 and output member 19 rotate at the same speed. The speed of the ring gear member
44, and therefore the output member 19, is determined from the speed of the sun gear member
42, the speed of the planet carrier assembly member 46 and the ring gear/sun gear tooth ratio of
the planetary gear set 40. The numerical value of the sixth forward speed ratio is determined
utilizing the ring gear/sun gear tooth ratios of the planetary gear sets 20, 30 and 40.
The seventh forward speed ratio is established with the engagement of the brakes
50, 54 and clutch 57. The brake 50 engages the sun gear member 22 with the transmission
housing 60. The brake 54 engages the planet carrier assembly member 36 and sun gear member
42 via interconnecting member 72 with the transmission housing 60. The clutch 57 engages the
sun gear member 32 with the planet carrier assembly member 46. The sun gear member 32 and
planet carrier assembly member 46 rotate at the same speed as the input member 17. The planet
carrier assembly member 36, sun gear member 42 and sun gear member 22 do not rotate. The
ring gear member 34 and ring gear member 24 rotate at the same speed. The speed of the ring
gear member 34 is determined from the speed of the sun gear member 32 and the ring gear/sun
gear tooth ratio of the planetary gear set 30. The ring gear member 44 and output member 19
rotate at the same speed. The speed of the ring gear member 44, and therefore the output
member 19, is determined from the speed of the planet carrier assembly member 46 and the ring

gear/sun gear tooth ratio of the planetary gear set 40. The numerical value of the seventh forward
speed ratio is determined utilizing the ring gear/sun gear tooth ratios of the planetary gear sets 30
and 40.
The eighth forward speed ratio is established with the engagement of the brakes
50, 52 and the clutch 57. The brake 50 engages the sun gear member 22 with the transmission
housing 60. The brake 52 engages the ring gear member 34 and ring gear member 24 via
interconnecting member 70 with the transmission housing 60. The clutch 57 engages the sun
gear member 32 with the planet carrier assembly member 46. The sun gear member 32 and
planet carrier assembly member 46 rotate at the same speed as the input member 17. The ring
gear member 34 and planetary gear set 20 do not rotate. The planet carrier assembly member 36
and sun gear member 42 rotate at the same speed. The speed of the planet carrier assembly
member 36 is determined from the speed of the sun gear member 32 and the ring gear/sun gear
tooth ratio of the planetary gear set 30. The ring gear member 44 and output member 19 rotate at
the same speed. The speed of the ring gear member 44, and therefore the output member 19, is
determined from the speed of the sun gear member 42, the speed of the planet carrier assembly
member 46 and the ring gear/sun gear tooth ratio of the planetary gear set 40. The numerical
value of the eighth forward speed ratio is determined utilizing the ring gear/sun gear tooth ratios
of the planetary gear sets 30 and 40.
As set forth above, the engagement schedule for the torque-transmitting
mechanisms is shown in the truth table of Figure lb. This truth table also provides an example
of speed ratios and ratio steps that are available in the above described transmission. For
example, the step ratio between the first and second forward speed ratios is 1.43, while the
step ratio between the reverse speed ratio and first forward ratio is -0.59.
The powertrain 10 may share components with a hybrid vehicle, and such a
combination may be operable in a "charge-depleting mode". For purposes of the present
invention, a "charge-depleting mode" is a mode wherein the vehicle is powered primarily by an
electric motor/generator such that a battery is depleted or nearly depleted when the vehicle
reaches its destination. In other words, during the charge-depleting mode, the engine 12 is only

operated to the extent necessary to ensure that the battery is not depleted before the destination is
reached. A conventional hybrid vehicle operates in a "charge-sustaining mode", wherein if the
battery charge level drops below a predetermined level (e.g., 25%) the engine is automatically
run to recharge the battery. Therefore, by operating in a charge-depleting mode, the hybrid
vehicle can conserve some or all of the fuel that would otherwise be expended to maintain the
25% battery charge level in a conventional hybrid vehicle. It should be appreciated that a hybrid
vehicle powertrain is preferably only operated in the charge-depleting mode if the battery can be
recharged after the destination is reached by plugging it into an energy source.
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.

WE CLAIM
1. An improved transmission (14) providing multiple forward speed ratios
and a reverse speed ratio, comprising:
an input member (17);
an output member (19);
first, second and third planetary gear sets (20,30,40) each having first,
second and third members;
a first interconnecting member (70) continuously connecting said third
member (24) of said first planetary gear set (20) with said third member
(34) of said second planetary gear set (30);
a second interconnecting member (72) continuously connecting said
second member (36) of said second planetary gear set (30) with said first
member (42) of said third planetary gear set (40);
a first torque-transmitting mechanism (50) selectively connecting said first
member (22) of said first planetary gear set (20) with a stationary
member (60);
a second torque-transmitting mechanism (52) selectively connecting said
third member (34) of said second planetary gear set (30) with said
stationary member (60);
a third torque-transmitting mechanism (54) selectively connecting said
second member (36) of said second planetary gear set (30) with said

stationary member (60);
a fourth torque-transmitting mechanism (56) selectively connecting said
second member (26) of said first planetary gear set (20) with said second
member (36) of said second planetary gear set (30);
a fifth torque-transmitting mechanism (58) selectively connecting said
second member (26) of said first planetary gear set (20) with said second
member (36) of said third planetary gear set (30);
a sixth torque-transmitting mechanism (60) selectively connecting said
first member (32) of said second planetary gear set (30) with said second
member (36) of said third planetary gear set (40);
said torque-transmitting mechanisms (50,52,54,56,58,60) being engaged
in combinations of three to establish eight forward speed ratios and one
reverse speed ratio between said input member (17) and said output
member (19).
2. The transmission as claimed in claim 1, wherein said first, second and
third torque-transmitting mechanisms (50,52,54) comprises brakes, and
said fourth, fifth and sixth torque-transmitting mechanisms (56,58,60)
comprise clutches.
3. The transmission as claimed in claim 1, wherein said first (22,32,42),
second (26,36,46) and third members (24,34,44) of said first, second and

third planetary gear sets (20,30,40) comprise a sun gear member, a
planet carrier assembly member and a ring gear member, respectively.
4. The transmission as claimed in claim 1, wherein said input member (17) is
continuously interconnected with said first member (32) of said second
planetary gear set (30), and said output member (19) is continuously
interconnected with said third member (44) of said third planetary gear
set (40).
5. An improved transmission (14) providing multiple forward speed ratios
and a reverse speed ratio, comprising:
an input member;
an output member;
first, second and third planetary gear sets each having a sun gear
member, planet carrier assembly member and ring gear member;
said input member being continuously interconnected with said sun gear
member of said second planetary gear set;
said output member being continuously interconnected with said ring gear
member of said third planetary gear set;
a first interconnecting member continuously connecting said ring gear
member of said first planetary gear set with said ring gear member of said

second planetary gear set;
a second interconnecting member continuously connecting said planet
carrier assembly member of said second planetary gear set with said sun
gear member of said third planetary gear set;
a first torque-transmitting mechanism selectively connecting said sun gear
member of said first planetary gear set with a stationary member;
a second torque-transmitting mechanism selectively connecting said ring
gear member of said second planetary gear set with said stationary
member;
a third torque-transmitting mechanism selectively connecting said planet
carrier assembly member of said second planetary gear set with stationary
member;
a fourth torque-transmitting mechanism selectively connecting said planet
carrier assembly member of said first planetary gear set with said planet
carrier assembly member of said second planetary gear set;
a fifth torque-transmitting mechanism selectively connecting said planet
carrier assembly member of said first planetary gear set with said planet
carrier assembly member of said third planetary gear set; and
a sixth torque-transmitting mechanism selectively connecting said sun
gear member of said second planetary gear set with said planet carrier

assembly member of said third planetary gear set;
said torque-transmitting mechanisms being engaged in combinations of
three to establish eight forward speed ratios and one reverse speed ratio
between said input member and said output member.



ABSTRACT


TITLE : "AN IMPROVED TRANSMISSION PROVIDING MULTIPLE
FORWARD SPEED RATIO AND ONE REVERSE SPEED RATIO"
The transmission (14) has a plurality of members that can be utilized in
powertrains to provide eight forward speed ratios and one reverse speed ratio.
The transmission (14) comprises three planetary gear sets (20,30,40) having six
torque-transmitting mechanisms (50,52,54,56,58,60) and two fixed
interconnections (70,72). The powertrain (10) comprises an engine and torque
converter (12) that is continuously connected to one of the planetary gear
members and an output member (19) that is continuously connected with
another one of the planetary gear members. The six torque-transmitting
mechanisms provide interconnections between various gear members, the
transmission housing (60) and with the input member (17), and are operated in
combinations of three to establish eight forward speed ratios and one reverse
speed ratio.

Documents:

00734-kol-2008-abstract.pdf

00734-kol-2008-claims.pdf

00734-kol-2008-correspondence others.pdf

00734-kol-2008-description complete.pdf

00734-kol-2008-drawings.pdf

00734-kol-2008-form 1.pdf

00734-kol-2008-form 2.pdf

00734-kol-2008-form 3.pdf

00734-kol-2008-form 5.pdf

0734-KOL-2008-CORRESPONDENCE OTHERS 1.2.pdf

0734-KOL-2008-PRIORITY DOCUMENT.pdf

649-KOL-2008-CORRESPONDENCE OTHERS 1.1.pdf

649-KOL-2008-OTHERS.pdf

734-KOL-2008-(06-11-2013)-ABSTRACT.pdf

734-KOL-2008-(06-11-2013)-ANNEXURE TO FORM 3.pdf

734-KOL-2008-(06-11-2013)-CLAIMS.pdf

734-KOL-2008-(06-11-2013)-CORRESPONDENCE.pdf

734-KOL-2008-(06-11-2013)-DESCRIPTION (COMPLETE).pdf

734-KOL-2008-(06-11-2013)-DRAWINGS.pdf

734-KOL-2008-(06-11-2013)-FORM-1.pdf

734-KOL-2008-(06-11-2013)-FORM-2.pdf

734-KOL-2008-(06-11-2013)-OTHERS.pdf

734-KOL-2008-(06-11-2013)-PA.pdf

734-KOL-2008-(06-11-2013)-PETITION UNDER RULE 137.pdf

734-KOL-2008-ASSIGNMENT-1.1.pdf

734-KOL-2008-ASSIGNMENT.pdf

734-KOL-2008-CANCELLED PAGES.pdf

734-KOL-2008-CORRESPONDENCE OTHERS 1.1.pdf

734-KOL-2008-CORRESPONDENCE.pdf

734-KOL-2008-EXAMINATION REPORT.pdf

734-KOL-2008-FORM 18-1.1.pdf

734-kol-2008-form 18.pdf

734-KOL-2008-GPA.pdf

734-KOL-2008-GRANTED-ABSTRACT.pdf

734-KOL-2008-GRANTED-CLAIMS.pdf

734-KOL-2008-GRANTED-DESCRIPTION (COMPLETE).pdf

734-KOL-2008-GRANTED-DRAWINGS.pdf

734-KOL-2008-GRANTED-FORM 1.pdf

734-KOL-2008-GRANTED-FORM 2.pdf

734-KOL-2008-GRANTED-FORM 3.pdf

734-KOL-2008-GRANTED-FORM 5.pdf

734-KOL-2008-GRANTED-SPECIFICATION-COMPLETE.pdf

734-KOL-2008-OTHERS.pdf

734-KOL-2008-PETITION UNDER RULE 137.pdf

734-KOL-2008-REPLY TO EXAMINATION REPORT.pdf

734-KOL-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-00734-kol-2008.jpg


Patent Number 264140
Indian Patent Application Number 734/KOL/2008
PG Journal Number 50/2014
Publication Date 12-Dec-2014
Grant Date 09-Dec-2014
Date of Filing 17-Apr-2008
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS INC.
Applicant Address 300 GM RENAISSANCE CENTER, DETROIT, MICHIGAN
Inventors:
# Inventor's Name Inventor's Address
1 JAMES M. HART 16011 HAGGERTY BELLEVILLE, MICHIGAN 48111
2 CLINTON E. CAREY 215 RIVERVIEW AVENUE MONROE, MICHIGAN 48162
3 SCOTT H. WITTKOPP 6189 OAKHURST DRIVE, YPSILANTI, MICHIGAN 48197
4 MADHUSUDAN RAGHAVAN 6816 TRAILVIEW COURT WEST BLOOMFIELD, MICHIGAN 48322
5 ANDREW W. PHILLIPS 1052 CUTLER CIRCLE SALINE, MICHIGAN 48176
PCT International Classification Number F16H3/44; F16H3/44
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/757681 2007-06-04 U.S.A.