Escapement drive for counting mechanisms

Claim 1

An escapement drive mechanism for counting devices, in which electric current pulses emanating from a primary pulse source are converted into successive angular steps of a counting mechanism, comprising a support plate; an electromagnetic system including coils mounted on said support plate; the electromagnet coils of said electromagnetic system being connected to receive current pulses from said primary pulse source; an escape wheel mounted for rotation on said support plate; a plurality of teeth for said escape wheel; a second hand mounted on the rotational axis of the escape wheel; a first pivot axis supported by said support plate; a second pivot axis supported by said support plate, said first and said second pivot axes being equally spaced from the center of said escape wheel; a first arm pivotally mounted on said first pivot axis; a second arm pivotally mounted on said second pivot axes, said second arm being similar to said first arm and being pivotally connected with the first arm; a first arcuate magnet member supported on an extremity of said first arm, said first magnet member facing said escape wheel, and adapted to cooperate with said coils of said electromagnetic system, when said current pulses are supplied thereto; a second arcuate magnet member supported on an extremity of said second arm, said second magnet member facing said escape wheel, and adapted to cooperate with said coils Of said electromagnetic system, when said current pulses are supplied thereto; the radius of curvature of said first and second arcuate magnet members being equal to the length of their respective arms from said respective pivot axes thereof; pallet pin means carried by each of said first and second arms; the pivot axis of one of said arms being disposed to one side of a straight line passing through the center of said escape wheel by an angle equal to half the pitch of the teeth of the escape wheel so that each of the pallet pin means moves the escape wheel precisely through half the pitch of the teeth thus ensuring a symmetric operation; said pallet pin means being arranged on said arms at a distance less than the diameter of the escape wheel; said respective ones of said pallet pin means being adapted to operate alternately at moments, when said coils of said electromagnetic system cooperate with said arcuate magnet members, whereby said current pulses are transformed into successive equal angular steps of said counting mechanism in equal time intervals.