Patents by Inventor Sekhar Raghavan

Sekhar Raghavan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6398690
    Abstract: A powertrain has an engine, torque converter, and planetary transmission that includes an input shaft, an output shaft, two simple planetary gear sets, rive rotating torque transmitting mechanisms (clutches) and one stationary torque transmitting mechanism (brake). The planetary gear sets are interconnected with both a permanent interconnection and a selective interconnection. A first member of a first of the planetary gear sets is continuously connected with the output shaft and a first member of the second planetary gear set is continuously connected with a stationary portion of the transmission. Two of the clutches are operable to selectively connect the input shaft with the second and third members of the first planetary gear set, respectively. A third of the clutches is connectable between the second member of the second planetary gear set and the output shaft. The brake is selectively connectable between the second member of the first planetary gear set and the stationary portion.
    Type: Grant
    Filed: October 30, 2000
    Date of Patent: June 4, 2002
    Assignee: General Motors Corporation
    Inventors: Kumaraswamy V. Hebbale, Sekhar Raghavan, Patrick Benedict Usoro
  • Patent number: 6213909
    Abstract: A powertrain has a multi-speed power transmission incorporating two planetary gear sets, four friction mechanisms and a selectively operable mechanical drive connection that are controlled to provide five forward speed ratios, a neutral condition and a reverse speed ratio. The mechanical drive connection is disposed to interconnect two members of the planetary gear sets during forward drive conditions and to connect one of the members with an input shaft during the reverse speed ratio. The mechanical drive connection is disconnected from all members during the neutral condition. Two of the friction mechanisms are clutches, one of which is selectively engageable to interconnect two members of the planetary gear sets, and the other of which is selectively engageable to connect the input shaft with a member of one of the planetary gear sets. The other two friction mechanisms are selectively engageable brakes that are effective to establish reaction members in the planetary gear sets.
    Type: Grant
    Filed: October 4, 1999
    Date of Patent: April 10, 2001
    Assignee: General Motors Corporation
    Inventor: Sekhar Raghavan
  • Patent number: 6193626
    Abstract: A powertrain has an engine, torque converter and a multi-speed transmission. The multi-speed transmission has a planetary gear arrangement disposed between an input shaft and an output shaft. The planetary gear arrangement consists of a simple planetary gear set and a compound planetary gear set that are interconnected and controlled by six torque transmitting mechanisms to provide six forward speed ratios and a reverse speed ratio between the input shaft and output shaft. Each of the torque transmitting mechanisms is engaged during at least two of the speed ratios. One of the torque transmitting mechanisms is established during six of the speed ratios including the reverse speed ratio.
    Type: Grant
    Filed: November 22, 1999
    Date of Patent: February 27, 2001
    Assignee: General Motors Corporation
    Inventors: Kumaraswamy V. Hebbale, Sekhar Raghavan, Patrick Benedict Usoro
  • Patent number: 6174256
    Abstract: A powertrain has an engine and torque converter that provides power to a multi-speed planetary transmission. The transmission includes a compound planetary gear set and a simple planetary gear set that are selectively interconnected by a plurality of selectively engageable torque transmitting mechanisms. The planetary carrier assembly member of the compound planetary gear set is continually connected to be driven by the torque converter, and the ring gear of the simple planetary gear set is connected to continually drive the transmission output shaft. A plurality of torque transmitting mechanisms, including the interconnecting mechanisms, are selectively engaged in combinations of three to establish six forward speed ratios and a reverse ratio.
    Type: Grant
    Filed: November 22, 1999
    Date of Patent: January 16, 2001
    Assignee: General Motors Corporation
    Inventors: Kumaraswamy V. Hebbale, Sekhar Raghavan, Patrick Benedict Usoro
  • Patent number: 6165097
    Abstract: A powertain includes an engine and torque converter arranged to provide input power to a six speed planetary transmission. The transmission includes a simple planetary gear set and a compound planetary gear set that are selectively interconnected by a pair of fluid-operated clutch mechanisms. Two other selectively engageable fluid-operated clutch mechanisms and three selectively engageable fluid-operated brake mechanisms are provided to control the power input and reaction within the planetary transmission. The clutch mechanisms and the brake mechanisms are engaged in combinations of three to provide six forward speed ratios and at least one reverse speed ratio between a transmission input shaft and a transmission output shaft.
    Type: Grant
    Filed: November 22, 1999
    Date of Patent: December 26, 2000
    Assignee: General Motors Corporation
    Inventors: Kumaraswamy V. Hebbale, Sekhar Raghavan, Patrick Benedict Usoro
  • Patent number: 6165098
    Abstract: A powertrain has an engine, torque converter and multi-speed transmission. The transmission has a simple planetary gear set and a compound planetary gear set. The gear sets are interconnected between the sun gear member of the simple planetary and the carrier assembly member of the compound planetary. The simple planetary ring gear member is continuously connected with an output shaft and the sun gear member of the compound planetary is continuously connected with an input shaft. Four clutches and two brakes are selectively engaged in pairs to provide six forward speed ratios and one reverse ratio.
    Type: Grant
    Filed: November 22, 1999
    Date of Patent: December 26, 2000
    Assignee: General Motors Corporation
    Inventors: Kumaraswamy V. Hebbale, Sekhar Raghavan, Patrick Benedict Usoro
  • Patent number: 6146305
    Abstract: A powertrain has an engine-driven power transmission that selectively provides six forward speed ratios, a neutral condition and a reverse speed ratio. The power transmission includes two simple planetary gear sets that are continuously interconnected between two members and selectively interconnected between two other members through a selectively engageable rotating torque-transmitting mechanism. The ring gear member of one of the planetary gear sets is continually connected with an output shaft. Three selectively engageable rotating torque-transmitting mechanisms connect a member of each planetary gear set as well as the interconnected members with an input shaft. Two selectively engageable stationary torque-transmitting mechanisms inhibit the rotation of two members of one of the planetary gear and one member of the other planetary gear set when the selectively engageable interconnection is active.
    Type: Grant
    Filed: August 27, 1999
    Date of Patent: November 14, 2000
    Assignee: General Motors Corporation
    Inventors: Kumaraswamy V. Hebbale, Sekhar Raghavan, Patrick Benedict Usoro
  • Patent number: 6056665
    Abstract: A five speed planetary transmission has a simple planetary gear set, a compound planetary gear set and six torque transmitting devices which are engaged in combinations of three to provide five forward ratios and one reverse ratio. The planetary gear sets are interconnected with a continuous drive connection and one of the torque transmitting devices. Two of the transmitting devices are input clutches and the other three are brakes. The planetary carrier assembly member of the simple planetary gear set is the only member connected with the output shaft during all of the ratios. The ratio interchanges in both single step and double step forward interchanges are of the single transition type.
    Type: Grant
    Filed: October 9, 1998
    Date of Patent: May 2, 2000
    Assignee: General Motors Corporation
    Inventors: Sekhar Raghavan, Kumaraswamy V. Hebbale, Patrick Benedict Usoro
  • Patent number: 6007450
    Abstract: A powertrain has a planetary gear arrangement with a simple planetary gear set and a compound planetary gear set which are interconnected by a continuous drive connection and are controlled to provide five forward drive ratios, a reverse drive ratio and a neutral condition. A plurality of torque transmitting devices including four clutches and two brakes are engaged in combination of three for each drive ratio. Two of the torque transmitting devices are engaged during the lowest forward drive ratio, the reverse drive ratio and the neutral condition.
    Type: Grant
    Filed: October 20, 1998
    Date of Patent: December 28, 1999
    Assignee: General Motors Corporation
    Inventors: Sekhar Raghavan, Kumaraswamy V. Hebbale, Patrick Benedict Usoro
  • Patent number: 5997429
    Abstract: A planetary transmission has two planetary gear sets, one of which is a simple planetary gear set. The ring gear of the simple planetary gear set is continuously connected with a transmission output shaft. Six fluid-operated friction torque transmitting devices are operable in combinations of three to establish a reverse drive and five forward drive ratios in the two gear sets. The gear sets are continuously interconnected by at least one drive member and are selectively interconnected by one of the torque transmitting devices. Two of the three devices engaged for reverse and first are also engaged in neutral.
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: December 7, 1999
    Assignee: General Motors Corporation
    Inventors: Sekhar Raghavan, Kumaraswamy V. Hebbale, Patrick Benedict Usoro
  • Patent number: 5984825
    Abstract: A planetary gear arrangement has two simple planetary gearsets and six selectively engageable friction torque transmitting mechanisms which are controlled to establish five forward transmission ratios and one reverse transmission ratio. One of the planetary gearsets establishes one forward ratio and the reverse ratio. The two planetary gearsets are compounded through both a continuous torque transmitting connection and a selectively engageable drive connection comprised of one of the torque transmitting mechanism during the two lowest forward transmission ratios and through the continuous torque transmitting connection during the highest of the forward transmission ratios. Both planetary gearsets are maintained in a direct drive ratio during the numerically central (third) forward ratio.
    Type: Grant
    Filed: August 31, 1998
    Date of Patent: November 16, 1999
    Assignee: General Motors Corporation
    Inventors: Kumaraswamy V. Hebbale, Sekhar Raghavan, Patrick Benedict Usoro
  • Patent number: 5951432
    Abstract: A planetary gearing arrangement has a compound planetary gear set and a simple planetary gear set. The planetary gear sets are continuously interconnected at the sun gear members and are interconnectable through the selective engagement of two proportioning clutches which change the interaction of the gear sets. A single member, a ring gear, is continuously connected to an output shaft. The arrangement also includes two input clutches and two brakes which in combination with the proportioning clutches permit the establishment of five forward ratios and one reverse ratio. Two of the forward ratios are underdrives and two of the ratios are overdrives. All of the forward ratio interchanges, the neutral to forward ratio change and the neutral to reverse ratio change are of the single transition type.
    Type: Grant
    Filed: October 27, 1998
    Date of Patent: September 14, 1999
    Assignee: General Motors Corporation
    Inventors: Jeffrey Bodley Wehking, Kumaraswamy V. Hebbale, Sekhar Raghavan, Patrick Benedict Usoro
  • Patent number: 5879264
    Abstract: A powertrain has a planetary transmission with two simple planetary gearsets interconnected between an input shaft and an output shaft. The planetary gearsets are controlled to establish five forward speed and torque ratios and one reverse speed and torque ratio by selective engagement of three clutches and two brakes.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: March 9, 1999
    Assignee: General Motors Corporation
    Inventors: Sekhar Raghavan, Kumaraswamy V. Hebbale, Patrick Benedict Usoro
  • Patent number: 5836850
    Abstract: A simple planetary gearset, a compound pinion planetary gearset, two clutches and two brakes are combined to provide four forward speed ratios and a reverse ratio. One of the clutches provides an input connection while the other provides a planetary interconnection. The two brakes are connected with respective first and second members of the simple planetary gearset while the third member of the planetary is continuously driven by a power input. The compound pinion planetary gearset has one member continuously connected with a power output shaft, a second member connected with the input clutch and the interconnecting clutch, and a third member connected with one of the brakable members of the simple planetary gearset.
    Type: Grant
    Filed: June 4, 1997
    Date of Patent: November 17, 1998
    Assignee: General Motors Corporation
    Inventors: Sekhar Raghavan, Kumaraswamy V. Hebbale