Patents by Inventor Ashish Bagai
Ashish Bagai 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).
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Patent number: 10676177Abstract: The present invention relates to robotic landing gear for a rotorcraft that is designed to allow for landing on sloped and irregular surfaces. The robotic landing gear consists of articulated legs with contact sensors. Once the contact sensor touches a landing surface, the articulated leg in which contact is detected retracts to maintain a certain amount of contact pressure with the surface. Each articulated leg does this independently until contact is detected on the sensors of all of the robotic legs, at which point the legs lock in position and the rotorcraft can safely land.Type: GrantFiled: May 27, 2016Date of Patent: June 9, 2020Inventors: Mark F. Costello, Michael Brian Ward, R Matthew Tallent, Ryan Hofmeister, Ashish Bagai
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Publication number: 20160122011Abstract: A rotor blade for a rotary wing aircraft includes a root region extending from a rotor head to about 15% to 20% of a blade radius, a main region extending from a radial extent of the root region to about 80% to 95% of the blade radius, a tip region extending from a radial extent of the main region to a blade tip, and a trailing edge. A portion of one of the root region, the main region and the tip region has an airfoil profile section including a trailing edge reflex camber relative to a base airfoil shape of a remainder of the one of the root region, the main region, and the tip region to reduce pitching moment of the rotor blade while maintaining a positive aerodynamic characteristic of the base airfoil shape. The reflex camber extends 20% of a blade chord from the trailing edge.Type: ApplicationFiled: November 30, 2015Publication date: May 5, 2016Inventor: Ashish Bagai
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Patent number: 9284050Abstract: A rotor blade for a rotary wing aircraft includes a root region extending from a rotor head to about 15% to 20% of a blade radius, a main region extending from a radial extent of the root region to about 80% to 95% of the blade radius, and a tip region extending from a radial extent of the main region to a blade tip. At least a portion of one of the root region, the main region and the tip region includes an airfoil profile section defined by a scaled set of coordinates in which a set of y/c coordinates listed in Table I are scaled by a selected factor.Type: GrantFiled: December 9, 2011Date of Patent: March 15, 2016Assignee: SIKORSKY AIRCRAFT CORPORATIONInventor: Ashish Bagai
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Publication number: 20130149160Abstract: A rotor blade for a rotary wing aircraft includes a root region extending from a rotor head to about 15% to 20% of a blade radius, a main region extending from a radial extent of the root region to about 80% to 95% of the blade radius, and a tip region extending from a radial extent of the main region to a blade tip. At least a portion of one of the root region, the main region and the tip region includes an airfoil profile section defined by a scaled set of coordinates in which a set of y/c coordinates listed in Table I are scaled by a selected factor.Type: ApplicationFiled: December 9, 2011Publication date: June 13, 2013Applicant: SIKORSKY AIRCRAFT CORPORATIONInventor: Ashish Bagai
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Patent number: 7600976Abstract: Main rotor blades of the dual, counter-rotating, rigid coaxial rotor system exhibit a unique unconventional combination of positive and negative twist gradients in which the rotor system rotor Figure of Merit (hover efficiency) is improved by providing a dissimilar twist distribution between the lower rotor blade and the upper rotor blades. This improvement is specifically a result of reduced profile drag of the lower rotor system, achieved by driving the effective operating condition of the lower rotor blades to be similar to the upper rotor blade such that the tip drag losses of the lower main rotor have been reduced considerably using a mathematically vigorous approach. While minimal induced power consumption resulted due to the dissimilar lower main rotor twist, a significant profile power benefit is realized, resulting in the improved hover efficiency with essentially no reduction in rotor forward flight performance.Type: GrantFiled: August 23, 2006Date of Patent: October 13, 2009Assignee: Sikorsky Aircraft CorporationInventors: Ashish Bagai, Lauren Kreuscher
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Patent number: 7513750Abstract: A main rotor blade incorporating a rotor blade tip region having a tip chord and a tip taper such that the ratio of the main rotor blade chord to the tip chord is approximately 0.30. The tip taper ratio preferably providing an approximately 28% area of reduction in said outer 10% of said blade span. The tip region preferably further including a hover optimized high lift airfoil and a tip sweep that reaches a constant value of approximately 30 degrees along the quarter chord line.Type: GrantFiled: March 8, 2006Date of Patent: April 7, 2009Assignee: Sikorsky Aircraft CorporationInventors: Robert C. Moffitt, Thomas Alan Egolf, Robert D. Beatty, John K. Karpowich, Ashish Bagai
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Publication number: 20070212223Abstract: A main rotor blade incorporating a rotor blade tip region having a tip chord and a tip taper such that the ratio of the main rotor blade chord to the tip chord is approximately 0.30. The tip taper ratio preferably providing an approximately 28% area of reduction in said outer 10% of said blade span. The tip region preferably further including a hover optimized high lift airfoil and a tip sweep that reaches a constant value of approximately 30 degrees along the quarter chord line.Type: ApplicationFiled: March 8, 2006Publication date: September 13, 2007Inventors: Robert Moffitt, Thomas Egolf, Robert Beatty, John Karpowich, Ashish Bagai
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Patent number: 7252479Abstract: A main rotor blade exhibiting a unique planform shape in which the blade chord increases from the root end of the blade inboard region to the outer main region of the blade, where the blade chord achieves a maximum chord at a spanwise location within the main region, then decreases toward a distal tip end. The leading edge preferably is generally straight while the trailing edge is contoured to define the chord. Another characteristic feature of the rotor blade design is the location of the blade-feathering axis in which the feathering axis is located at a mid chord position over some inboard length of the rotor blade then transitions to a quarter chord location. Another characteristic feature is an airfoil distribution along the blade span that transitions from a blunt trailing edge to a sharp trailing edge airfoil suited for mid-range Mach number operation. The tip region preferably utilizes a transonic flow airfoil.Type: GrantFiled: May 31, 2005Date of Patent: August 7, 2007Assignee: Sikorsky Aircraft CorporationInventors: Ashish Bagai, Robert C. Moffitt, Robert H. Blackwell, Jr., Timothy A. Krauss
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Publication number: 20070110582Abstract: Main rotor blades of the dual, counter-rotating, rigid coaxial rotor system exhibit a unique unconventional combination of positive and negative twist gradients in which the rotor system rotor Figure of Merit (hover efficiency) is improved by providing a dissimilar twist distribution between the lower rotor blade and the upper rotor blades. This improvement is specifically a result of reduced profile drag of the lower rotor system, achieved by driving the effective operating condition of the lower rotor blades to be similar to the upper rotor blade such that the tip drag losses of the lower main rotor have been reduced considerably using a mathematically vigorous approach. While minimal induced power consumption resulted due to the dissimilar lower main rotor twist, a significant profile power benefit is realized, resulting in the improved hover efficiency with essentially no reduction in rotor forward flight performance.Type: ApplicationFiled: August 23, 2006Publication date: May 17, 2007Inventors: Ashish Bagai, Lauren Kreuscher
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Publication number: 20060269418Abstract: A main rotor blade exhibiting a unique planform shape in which the blade chord increases from the root end of the blade inboard region to the outer main region of the blade, where the blade chord achieves a maximum chord at a spanwise location within the main region, then decreases toward a distal tip end. The leading edge preferably is generally straight while the trailing edge is contoured to define the chord. Another characteristic feature of the rotor blade design is the location of the blade-feathering axis in which the feathering axis is located at a mid chord position over some inboard length of the rotor blade then transitions to a quarter chord location. Another characteristic feature is an airfoil distribution along the blade span that transitions from a blunt trailing edge to a sharp trailing edge airfoil suited for mid-range Mach number operation. The tip region preferably utilizes a transonic flow airfoil.Type: ApplicationFiled: May 31, 2005Publication date: November 30, 2006Inventors: Ashish Bagai, Robert Moffitt, Robert Blackwell, Timothy Krauss
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Patent number: 6984109Abstract: A rotor blade assembly provides a pitch control assembly to pitch the rotor blade about a rotor blade pitch axis. The pitch control assembly includes a trailing edge flap and a trailing edge servo flap that extend from the trailing edge of the rotor blade. The trailing edge flap is offset in the span wise direction relative to the trailing edge flap. The trailing edge servo flap is located upon a trailing edge servo flap arm linked to the trailing edge flap. To pitch the rotor blade, the trailing edge servo flap is pitched in a direction opposite the desired pitch direction of the trailing edge flap.Type: GrantFiled: December 4, 2003Date of Patent: January 10, 2006Assignee: Sikorsky Aircraft CorporationInventor: Ashish Bagai
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Patent number: 6932569Abstract: A multi-element rotor blade includes an individually controllable main element and fixed aerodynamic surface in an aerodynamically efficient location relative to the main element. The main element is controlled to locate the fixed aerodynamic surface in a position to increase lift and/or reduce drag upon the main element at various azimuthal positions during rotation.Type: GrantFiled: December 27, 2002Date of Patent: August 23, 2005Assignee: Sikorsky Aircraft CorporationInventors: Michael S. Torok, Robert C. Moffitt, Ashish Bagai
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Publication number: 20050123400Abstract: A rotor blade assembly provides a pitch control assembly to pitch the rotor blade about a rotor blade pitch axis. The pitch control assembly includes a trailing edge flap and a trailing edge servo flap that extend from the trailing edge of the rotor blade. The trailing edge flap is offset in the span wise direction relative to the trailing edge flap. The trailing edge servo flap is located upon a trailing edge servo flap arm linked to the trailing edge flap. To pitch the rotor blade, the trailing edge servo flap is pitched in a direction opposite the desired pitch direction of the trailing edge flap.Type: ApplicationFiled: December 4, 2003Publication date: June 9, 2005Inventor: Ashish Bagai
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Publication number: 20050042091Abstract: A multi-element rotor blade includes an individually controllable main element and fixed aerodynamic surface in an aerodynamically efficient location relative to the main element. The main element is controlled to locate the fixed aerodynamic surface in a position to increase lift and/or reduce drag upon the main element at various azimuthal positions during rotation.Type: ApplicationFiled: December 27, 2002Publication date: February 24, 2005Inventors: Michael Torok, Robert Moffitt, Ashish Bagai