Patents Assigned to Detra SA
  • Patent number: 11112758
    Abstract: The invention relates to an escapement device (400) comprising a first escapement wheel (1), a second escapement wheel (2), and a brake-lever (3), said second escapement wheel being disposed between the first escapement wheel and the brake-lever, in particular the second escapement wheel coming into contact and engaging with both the first escapement wheel and the brake-lever.
    Type: Grant
    Filed: December 21, 2016
    Date of Patent: September 7, 2021
    Assignee: DETRA SA
    Inventor: Xuan Mai Tu
  • Publication number: 20180373201
    Abstract: The invention relates to an escapement device (400) comprising a first escapement wheel (1), a second escapement wheel (2), and a brake-lever (3), said second escapement wheel being disposed between the first escapement wheel and the brake-lever, in particular the second escapement wheel coming into contact and engaging with both the first escapement wheel and the brake-lever.
    Type: Application
    Filed: December 21, 2016
    Publication date: December 27, 2018
    Applicant: DETRA SA
    Inventor: Xuan Mai Tu
  • Patent number: 9323220
    Abstract: The invention relates to a timepiece fitted with a lever escapement wherein the end of contact angles ?1 and ?2 between the pallet stones and the escapement wheel are respectively higher than the locking-angles ?2 and ?1 of the two locking positions of the lever. This escapement requires neither adjustment nor final alteration of the position of the pallet stones.
    Type: Grant
    Filed: November 14, 2013
    Date of Patent: April 26, 2016
    Assignee: DETRA SA
    Inventor: Xuan Mai Tu
  • Publication number: 20150301501
    Abstract: The invention relates to a timepiece fitted with a lever escapement wherein the end of contact angles ?1 and ?2 between the pallet stones and the escapement wheel are respectively higher than the locking-angles ?2 and ?1 of the two locking positions of the lever. This escapement requires neither adjustment nor final alteration of the position of the pallet stones.
    Type: Application
    Filed: November 14, 2013
    Publication date: October 22, 2015
    Applicant: Detra SA
    Inventor: Xuan Mai Tu
  • Patent number: 9052694
    Abstract: Escapement device of a timepiece movement includes an escapement wheel, a first mobile having means of locking with the escapement wheel and of mechanical transmission with the escapement wheel, a second mobile and the balance roller. The second mobile has means of locking with the escapement wheel and means of mechanical transmission with the escapement wheel and the first mobile. The mobiles are driven by the escapement wheel tangentially.
    Type: Grant
    Filed: June 7, 2012
    Date of Patent: June 9, 2015
    Assignee: DETRA SA
    Inventor: Xuan Mai Tu
  • Publication number: 20150131414
    Abstract: Escapement device of a timepiece movement includes an escapement wheel, a first mobile having means of locking with the escapement wheel and of mechanical transmission with the escapement wheel, a second mobile and the balance roller. The second mobile has means of locking with the escapement wheel and means of mechanical transmission with the escapement wheel and the first mobile. The mobiles are driven by the escapement wheel tangentially.
    Type: Application
    Filed: June 7, 2012
    Publication date: May 14, 2015
    Applicant: DETRA SA
    Inventor: Xuan Mai Tu
  • Patent number: 6712500
    Abstract: The invention concerns an escapement device comprising a power source capable of delivering a variable torque based on the angle of rotation of a pinion fixed to said power source, said variable torque having at least a stable position and an unstable position. The device further comprises locking means capable of locking power transmission to an oscillator in a stable point of equilibrium and unlocking means capable of unlocking power transmission to said oscillator between a stable point of equilibrium and an unstable point of equilibrium.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: March 30, 2004
    Assignee: Detra SA
    Inventors: Xuan-Mai Tu, Michel Schwab
  • Patent number: 6335619
    Abstract: An inductive proximity sensor that uses a resonant oscillatory circuit to detect a target by changes to inductive reaction. The oscillating circuit has primary and secondary windings where a capacitor and load resistance are connected in parallel with the primary winding, the value of the load resistance is selected so that in a state of oscillation the ohmic losses in the load resistance are substantially higher than the ohmic losses in the primary winding, and the primary and secondary windings are disposed so that the mutual flux between the primary and secondary windings is substantially less than the particular flux of each winding.
    Type: Grant
    Filed: February 14, 2000
    Date of Patent: January 1, 2002
    Assignee: Detra SA
    Inventors: Michel Schwab, Xuan Mai Tu
  • Patent number: 5774426
    Abstract: The method and the device for feeding a single-phase stepping motor for a timepiece are adapted to provide the motor (M) with a sequence of chopped voltage pulses of variable duration as a function of load conditions and of feed voltage. The sequence of chopped voltage pulses comprises in particular a supplementary sequence of partial voltage pulses of constant duration (T.sub.4), separated from each other by variable intervals (T.sub.5i) defined by a reference current (I.sub.ref) whose value is adapted as a function of the level of load of the motor.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: June 30, 1998
    Assignee: Detra SA
    Inventors: Mai Xuan Tu, Michel Schwab
  • Patent number: 5504408
    Abstract: The method is designed to supply the motor with chopped voltage pulses of varying durations as a function of the load conditions and of the supply voltage. The chopped voltage pulse is composed of a plurality of partial pulses of predetermined durations T1, T2, and T3. The feeding circuit comprises a detector of a condition of extreme load defined by k1.multidot.T4<k2.multidot.T5, wherein k1 and k2 are constants, T4 is an interval separating T1 and T2, and T5 is an interval separating T2 and the first pulse T3.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: April 2, 1996
    Assignee: Detra SA
    Inventors: Mai X. Tu, Michel Schwab
  • Patent number: 5498958
    Abstract: An inductive proximity sensor determines if a metallic object is in close proximity. An inductor is placed near the object. Several switches control the direction of the voltage passing through the inductor. During a first time period, the voltage flows through the inductor to induce a magnetic field in the object. During the second time period, the voltage is reversed in the inductor to quickly eliminate any current in the inductor. The decaying magnetic field in the object induces a voltage in the inductor which is measured during a third time period and compared to a reference value to determine the proximity of the object to the sensor.
    Type: Grant
    Filed: November 3, 1993
    Date of Patent: March 12, 1996
    Assignee: Detra SA
    Inventors: Mai X. Tu, Michel Schwab
  • Patent number: 5429889
    Abstract: Apparatus and process for sorting used batteries and accumulators on the basis of their chemical constitution based on the analysis of the inductive effect produced by the substances which are contained in the battery or accumulator, and whose ferromagnetic properties differ according to their chemical constitution. The measurement process in which the apparatus is used is based on the consecutive application to the excitation circuit of at least two different voltage amplitudes at the same frequency or two different frequencies at the same voltage amplitude.
    Type: Grant
    Filed: September 25, 1992
    Date of Patent: July 4, 1995
    Assignees: Titalyse SA, Detra SA
    Inventors: Mai Tu Xuan, Thinh T. Nguyen, Jean P. Wia, Michel Schwab
  • Patent number: 5400303
    Abstract: The driving device comprises two single-phase stepping motors (1, 2), each having a different preferential direction of rotation. The bidirectional drive is achieved by selectively feeding one or the other of the two motors.
    Type: Grant
    Filed: April 27, 1993
    Date of Patent: March 21, 1995
    Assignee: Detra SA
    Inventors: Mai X. Tu, Michel Schwab
  • Patent number: 5247235
    Abstract: Method of supplying power to a single phase step motor of a time-piece, adapted to provide the motor with chopped voltage pulses of time-period T.sub.6 variable with respect to the load conditions and to the supply voltage of the motor, characterized in that each said impulsion of chopped voltage is composed of a sequence of elementary pulses of the same polarity and of a constant duration T.sub.4, and in that the durations T.sub.5i separating the said elementary voltage pulses vary according to load conditions and according to the supply voltage of the motor variable with respect to the load conditions and to the supply voltage of the motor.The invention finds a field of application in motors for time-pieces.
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: September 21, 1993
    Assignee: Detra SA
    Inventors: Mai X. Tu, Michel Schwab
  • Patent number: 5166590
    Abstract: The method and circuit are particularly suitable for use in timepieces and are adapted to supply the motor with chopped-voltage pulses of variable durations as a function of the load conditions of the motor. A chopped pulse of variable duration T.sub.7 is composed of a partial pulse T.sub.4 of fixed duration and of a constant number of partial pulses T.sub.6i of variable duration, spaced by intervals T.sub.5i which are themselves determined by the duration of current drop between the preceding peak and a reference value. The durations T.sub.6i are proportional to the intervals T.sub.5i.
    Type: Grant
    Filed: February 11, 1991
    Date of Patent: November 24, 1992
    Assignee: Detra SA
    Inventors: Mai X. Tu, Michel Schwab