Patents Assigned to Chadwick-Helmuth Company, Inc.
  • Patent number: 6139271
    Abstract: Rotor blade weighting apparatus comprising in combination at least one elongated rod carried within a rotor blade, and multiple weights received and retained on the rod, the number of weights adjustable for reducing vibration during rotor rotation.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: October 31, 2000
    Assignee: Chadwick-Helmuth Company, Inc.
    Inventor: James R. Chadwick
  • Patent number: 4531408
    Abstract: The invention concerns method and apparatus to obtain accurate tracking of rotor blades, as for example helicopter rotor blades, despite the existence of conditions transiently altering rotor angular velocity.
    Type: Grant
    Filed: December 6, 1982
    Date of Patent: July 30, 1985
    Assignee: Chadwick-Helmuth Company, Inc.
    Inventors: James R. Chadwick, Lloyd N. Johnson
  • Patent number: 4112774
    Abstract: Vibration of a bladed rotor is reduced by a method that includes:(a) rotating the rotor at a selected power level, at which vibration is produced,(b) detecting an out-of-track condition of a blade being rotated at that power level.
    Type: Grant
    Filed: January 7, 1977
    Date of Patent: September 12, 1978
    Assignee: Chadwick-Helmuth Company, Inc.
    Inventor: James R. Chadwick
  • Patent number: 4053123
    Abstract: The output of an aircraft propulsion or lift rotor blade out-of-track pick-up is processed in such a way as to enable quick determination of need for blade pitch adjustment, the approximate amount of such adjustment to optimize reduction of out-of-track vibration, and the need for blade substitution when such optimized reduction is insufficient.
    Type: Grant
    Filed: April 16, 1976
    Date of Patent: October 11, 1977
    Assignee: Chadwick-Helmuth Company, Inc.
    Inventor: James R. Chadwick
  • Patent number: 3945256
    Abstract: The method of balancing a rotor having multiple blades and defining an axis of rotation, and wherein structure proximate the rotor is subject to vibratory motion due to dynamic unbalance of the rotating rotor and an out-of-track condition of the rotor blades, the method employing two vibration pickups, the method including:A. operating the pickups to produce vibratory signals corresponding to up and down vibratory motion of the structure at port and starboard sides of said axis,B. combining said signals to produce a resultant oscillatory output signal characteristic of rotor vibratory motion due substantially to only one of said conditions,C. using said resultant output signal to alleviate said one condition.
    Type: Grant
    Filed: April 21, 1975
    Date of Patent: March 23, 1976
    Assignee: Chadwick-Helmuth Company, Inc.
    Inventors: William F. Wilson, James R. Chadwick, James G. Helmuth
  • Patent number: 3944876
    Abstract: A starting device for a gas discharge lamp, to whose electrodes AC voltage is applied, comprises:A. first means electrically connected with at least one lamp electrode to apply to the lamp a transient voltage pulse which initially changes in amplitude in a polarity direction relatively in opposition to the polarity of the main voltage simultaneously supplied to the electrodes,B. said first means including circuitry to cause said pulse to thereafter change in amplitude in a polarity direction in aid of the polarity of the main voltage simultaneously supplied to the electrodes.
    Type: Grant
    Filed: September 30, 1974
    Date of Patent: March 16, 1976
    Assignee: Chadwick-Helmuth Company, Inc.
    Inventor: James G. Helmuth
  • Patent number: RE31486
    Abstract: A starting device for a gas discharge lamp, to whose electrodes AC voltage is applied, comprises:a. first means electrically connected with at least one lamp electrode to apply to the lamp a transient voltage pulse which initially changes in amplitude in a polarity direction relatively in opposition to the polarity of the main voltage simultaneously supplied to the electrodes,b. said first means including circuitry to cause said pulse to thereafter change in amplitude in a polarity direction in aid of the polarity of the main voltage simultaneously supplied to the electrodes.
    Type: Grant
    Filed: May 20, 1982
    Date of Patent: January 3, 1984
    Assignee: Chadwick-Helmuth Company, Inc.
    Inventor: James G. Helmuth