Method of and apparatus for the autosynchronization of an electromagnetic hammer
AssigneeMartelec Societe Civile Particuliere
InventorGeorges Jacquemet
Life of this patent
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Abstract
An electromagnet hammer of the type described in U.S. Pat. No. 4,215,297 is autosynchronized by triggering the discharge thyristor in response to the detection of the position of the armature by a proximity detector, or by direct detection of the zero passage of the negative amplitude of the discharge current, or at a reference point representing the position of the armature, with a delay equal to at least half the period of the natural period of oscillation of the armature/plunger and its elastic suspension.
Claims13
In a method of autosynchronously operating an electromagnetic hammer comprising an electromagnet having a coil within which an elastically suspended plunger armature is displaceable in successive operation cycles by energization of the coil to generate an impact upon the discharge of a condenser under the control of a discharge thyristor through the coil, the condenser being charged from a direct current source through an inductance under the control of a charging thyristor in series with the coil, the improvement which comprises:
- generating a command pulse triggering said discharge thyristor at a predetermined interval at least equal to the half period of the natural oscillation frequency of said plunger armature and its elastic suspension after the negative amplitude of the discharge current from the condenser through the coil attains a zero value for the first time in each operating cycle of the hammer so that triggering of the hammer is controlled on an impact-by-impact basis in accordance with its position resulting from a previous triggering.
In an electromagnetic hammer comprising an electromagnet having a coil within which an elastically suspended plunger armature is displaceable in successive operating cycles by energization of the coil to generate an impact upon the discharge of a condenser under the control of a discharge thyristor through the coil, the condenser being charged from a direct current source through an inductance under the control of a charging thyristor in series with the coil, the improvement which comprises for autosynchronization:
- a first circuit producing a pulse of a duration equal to a predetermined fraction of the period of the natural oscillation frequency of the plunger armature and its elastic suspension;
- a second circuit receiving said pulse and generating another pulse;
- a third circuit forming an interface and receiving said other pulse for generating a spike triggering said discharge thyristor for discharging said condenser through said coil;
- a fourth circuit producing a further pulse of a predetermined duration;
- a fifth circuit receiving said further pulse;
- and
- a sixth circuit forming an interface and connected to said fifth circuit for generating a spike triggering said charging thyristor.
Dependencies are inferred from the claim text.