Abstract: A direct-current motor-generator comprises at least one stationary magnetic circuit including a permanent magnet and forming an air gap of substantially cylindrical shape, and a generally cup shaped rotor bearing a motor winding and a generator winding. The arrangement of the at least one magnetic circuit and the windings is such that the magnetic flux passing through the one of the said windings is separated in space from the flux passing through the other of the said windings.

Abstract: The invention relates to miniature electric motors, more particularly to monophase synchronous motors of the type the motor of which includes two pole pieces respectively polarized positively and negatively by the current circulating in an energizing coil, these pole pieces having each N teeth and defining a gap in which is placed a thin, disc-shaped rotor of hard magnetic material. The rotor comprises two annular coaxial portions magnetized with respectively N and N/2 pairs of alternately positive and negative poles.These motors can be adapted to step-by-step working under constant sign pulse feed and are particularly suitable for use in cases where size and power consumption must be reduced to a minimum, such as in electric clockwork movements.

Abstract: The rotor of an electric direct current rotating machine has at least one winding which cooperates with a stationary magnetic circuit. The winding is formed of several sections connected in series. The respective opposite ends of each section are connected to adjacent segments of a commutator associated with the winding. The sections are arranged on the rotor in such a manner that portions of different adjacent sections are disposed concurrently in the commutation zone so that currents flow through these portions in opposite directions. The invention finds application in particular to direct current motors and to motor-generators.

Abstract: A method of and apparatus for measuring the amplitude of oscillation of the balance of a timepiece movement having an escapement adapted for disengagement and engagement, successively, the balance having a predetermined angle of lift. The time intervals between successive disengagement and engagement are measured, as are the durations of vibration of the balance. The number of pulses of a first frequency which are produced during at least one of the measured time intervals is counted. The number of pulses of a second frequency produced during at least one of the vibration durations also is counted. The first and second frequencies have a predetermined relationship with respect to each other. The number of counted pulses of the second frequency is divided by the number of counted pulses of the first frequency to thereby attain a quotient which is equal to the amplitude of oscillation.

Abstract: A shock absorber bearing assembly is disclosed which includes a shaft having a pivot end portion with a pivot end, a bearing housing having an opening therein through which the pivot end portion of the shaft extends; and a bearing mounted on the housing and having an aperture formed therein for receiving the end pivot section of the shaft. An enlargement is formed on the shaft below the end pivot section and is located in the housing opening. The latter has a first cylindrical section and a second tapered section between the cylindrical section and the bearing so that side play of the shaft between the enlargement and the housing opening decreases as the end pivot section moves out of the bearing during a shock load in order to automatically keep the shaft end centered with the bearing.