Patents by Inventor Mahesh J. Shah

Mahesh J. Shah 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: 5309081
    Abstract: A starting/generating system operable in a starting mode and in a generating mode utilizes a dual permanent magnet generator (DPMG) having a motive power shaft and an armature winding together with a power converter having an input and an output. Relays are operable in the starting mode to connect the output of the power converter to the DPMG armature winding and are operable in the generating mode to connect the input of the power converter to the DPMG armature winding. The power converter is controlled in the starting mode such that the DPMG is operated as a motor to produce motive power at the motive power shaft and is controlled in the generating mode such that electrical power developed in the DPMG armature winding is converted into output power.
    Type: Grant
    Filed: August 18, 1992
    Date of Patent: May 3, 1994
    Assignee: Sundstrand Corporation
    Inventors: Mahesh J. Shah, Alexander Cook
  • Patent number: 5097163
    Abstract: A brushless electrical power generating system (10) in accordance with the invention includes a main generator (16) having a rotor (30) on which is wound a field winding (32) and a stator (112) on which is wound a winding (36) for producing an alternating current electrical output having at least one phase; an exciter (14) having a rotor (24) mounted coaxial to the rotor of the main generator and a stator (110) on which is wound a stator winding (18) and an electrical field shield (40) disposed between the stators of the exciter and the main generator for shielding the winding of the stator of the main generator from an electric field produced by the winding of the stator of the exciter whereby capacitive coupling of any electrical noise present within the current flowing in the stator winding of the exciter to the alternating current electrical power output is reduced.
    Type: Grant
    Filed: December 22, 1989
    Date of Patent: March 17, 1992
    Assignee: Sundstrand Corporation
    Inventors: Mahesh J. Shah, Derek N. Walton, Clarence F. Dolan
  • Patent number: 5079462
    Abstract: A brushless generator in accordance with the present invention includes a main generator having a stator (12) on which is wound at least one phase winding (52-56), each phase winding producing a phase output (.PHI.A-.PHI.C); a number of current transformers (20-24) equal in number to a number of phases present in the main generator, each current transformer being magnetically coupled to a conductor (48) of a different phase winding; and a plurality of annular disks (40), equal in number of the number of phases, each annular disk having an annulus (46) containing the conductor of the phase winding of a different phase, slot (42) extending from an inner radius (44) defining the annulus to an outer radius (50) defining an outer cirucmference of the disk, each annular disk being held by a support (10) for the current transformer, having a permeability greater than 1020-type steel and attenuating harmonics of a fundamental frequency of AC produced by the main generator.
    Type: Grant
    Filed: February 27, 1990
    Date of Patent: January 7, 1992
    Assignee: Sundstrand Corporation
    Inventors: Mahesh J. Shah, Clarence F. Dolan, Derek N. Walton
  • Patent number: 5059884
    Abstract: A variable reluctance motor (10, 100, 200) for providing holding torque in accordance with the invention includes a magnetically permeable rotor (12); a stator (18) axially aligned with the rotor having at least one phase winding (22) for producing a magnetic field causing the rotor to rotate; and a first cylindrical magnet (26) mounted coaxial with and outboard from a first side of the rotor which creates a permanent magnetic field coupling the rotor to the magnet to provide holding torque.
    Type: Grant
    Filed: April 10, 1990
    Date of Patent: October 22, 1991
    Assignee: Sundstrand Corporation
    Inventors: Mahesh J. Shah, Jayant G. Vaidya
  • Patent number: 5034639
    Abstract: A stator drain supports stator windings and rotor bearings and permits fluid coolant for the rotor bearings to be drained outward past the stator windings from the bearings. The drain is formed of a non-metallic material and has an inner surface for supporting a bearing liner of the rotor bearings, a plurality of spaced openings for receiving stator windings and drain slots extending through the annular member at locations corresponding to spaces between the stator windings for draining the fluid coolant. The stator drain is useful in a dual permanent magnet generator, for example.
    Type: Grant
    Filed: June 19, 1990
    Date of Patent: July 23, 1991
    Assignee: Sundstrand Corporation
    Inventors: John B. Huss, Mahesh J. Shah
  • Patent number: 5023540
    Abstract: A brushless electrical power generating system (100) in accordance with the invention includes an exciter (14) for producing alternating current from an exciter rotor; a rectifier (20) mounted for rotation with the exciter rotor for producing a rectified control current from the AC current; a common mode inductor (112), coupled to the control current, for cancelling common mode noise components within the rectified control current; and a main generator (22), having a rotating field winding (24) mounted on a main generator rotor excited by the control current and producing an alternating current power output from a stator.
    Type: Grant
    Filed: December 22, 1989
    Date of Patent: June 11, 1991
    Assignee: Sundstrand Corporation
    Inventors: Derrick N. Walton, Clarence F. Dolan, Mahesh J. Shah
  • Patent number: 4847745
    Abstract: A three phase inverter (40) is disclosed for use with loads (100) which are unbalanced. A transformer (80) having primary windings (82), (84) and (86) which are respectively connected to phase outputs (52, 54 and 56) has a secondary having individual windings (88, 90 and 92) connected in a delta configuration which minimizes the flow of unbalanced current in the unbalanced load. A second embodiment utilizes a transformer in an interconnected configuration. A neutral connecting the conductive switches to the load is unnecessary with the invention.
    Type: Grant
    Filed: November 16, 1988
    Date of Patent: July 11, 1989
    Assignee: Sundstrand Corp.
    Inventors: Sampat S. Shekhawat, Mahesh J. Shah, Jayant G. Vaidya, John J. Dhyanchand
  • Patent number: 4093867
    Abstract: Apparatus for automatically calibrating smoke detectors within desired ranges of values of smoke obscuration, and thereafter retesting them for valid calibration; in accomplishing this the smoke obscuration is continuously increased at a predetermined uniform rate.
    Type: Grant
    Filed: October 27, 1976
    Date of Patent: June 6, 1978
    Assignee: General Signal Corporation
    Inventors: Mahesh J. Shah, Joseph P. Mallozzi