Adjustable mechanical oscillator for time-measuring apparatus

Claim 1

IN A TIME MEASURING APPARATUS; AN ELECTRICALLY MAINTAINED FEED BACK TYPE MECHANICAL OSCILLATOR OF TUNING FORK KIND COMPRISING TWO PARALLEL TINES. THE FREE ENDS OF WHICH ARE ADAPTED TO VIBRATE IN OPPOSITION, WHILE REMAINING ALWAYS EQUIDISTANT FROM THE LONGITUDINAL PLANE OF SYMMEETRY OF THE OSCILLATOR, PERMAANENT MAGNETS CARRIED SYMMETRICALLY BY SAID TINES NEAR THE FREE ENDS THEREOF, THE DIRECTION OF MAGNETISATION OF SAID PERMANENT MAGNETS BEING PARALLEL TO SAID PLANE OF SYMMETRY, A FIXED PICK UP WINDING AND A FIXED DRIVING WINDING FORMING TOGLETHER A SUBSTANTIALLY RECTANGULAR FLAT COIL LIMITED BY PLANES PERPENDICULAR TO SAID PLANE OF SYMMETRY AND HAVING ITS GEOMETRICAL AXIS OF SYMMETRY LYING IN SAID PLANE OF SYMMETRY EQUIDISTANT FROM SAID TWO TINES, TWO OPPOSITE SIDIES OF SAID COIL BEING RECTANGULAR FLAT COIL LIMITTED BY PLANES PERPENDDICULAR TO THE MAGNETIC FIELD GEENERATED BY SAID PEERMANENT MAGNETS BY WHICH THE ACTIVE CONDUCTORS FORMING SAID SIDES OF THE COIL ARE INFLUENCED DURING THE VIBRATORY MOVEMENTS OF SAID MAGNETS, A SOURCE OF DIRECT CURRENT AND AN AMPLIFIER OF A SEMI-CONDUCTOR TYPE FED BY SAID SOURCE OF D.C. CURRENT, SAID AMPLIFIER COMPRISING AN INPUT CIRCUIT CONNECTED TO THE SAID PICK-UP WINDING AND AN OUTPUT CIRCUIT CONNECTED TO SAID DRIVING WINDING, WHEREBY SAID DRIVING WINDING RECEIVES, AFTER AMPLIFICATION, THE PERIODIC CURRENT PULSES INDUCED IN THE SAID PUCK-UP WINDING BY THE VIBRATORY ADJUSTING MENTS OF SAID MAGNETS, MEANS FOR INDIVIDUALLY ADJUSTING THE FREQUENCY OF SAID VIBRATING TINES AND CONSISTING OF A SMALL INERTIA BLOCK MADE OF A SOFT MATERIAL CARRIED BY EACH TINE OF WHICH THE NATURAL FREQUENCY CAN BE ADJUSTED BY PROGRESSIVELY REMOVING MATERIAL FROM THE CORRESPONDING INERTIAL BLOCK.