Vibratory material feeder

Claim 2

A vibratory material feeder comprising: electromechanical vibratory actuator means for feeding material; drive means for applying a substantially sinusoidal electrical drive wave form to said actuator means; means for detecting a phase difference between a voltage and a current applied to said actuator means; means, responsive to said phase difference, for controlling said drive means to minimize said phase difference whereby said actuator means is driven substantially in mechanical resonance; means for detecting electrical power applied to said actuator means, and means, responsive to detected electrical power, for controlling said drive means to apply electrical power to said actuator means to feed material at a desired rate, said means responsive to said detected electrical power including, means for storing a representation of at least a portion of at least one substantially sinusoidal wave form, means for recalling said representation, and means for adjusting an amplitude of said representation according to said detected electrical power.

Claim 3

A vibratory material feeder as recited in claim 1 wherein aid drive means comprises: means for applying a substantially sinusoidal voltage to said actuator means, said voltage having a magnitude corresponding to said amplitude of said representation.

Claim 4

A vibratory material feeder as recited in claim 2 wherein said means for detecting electrical power comprises: means for determining a magnitude of said current applied to said actuator means; and means, responsive to said magnitude of said current, said magnitude of said voltage and said phase difference, for calculating electrical power applied to said actuator means.

Claim 5

A vibratory material feeder as recited in claim 3 further comprising: means for setting said desired rate; and wherein said means for adjusting said amplitude adjusts said amplitude proportional to a ratio of said desired rate and calculated electrical power applied to said actuator means.

Claim 6

A vibratory feeder as recited in claim 4 wherein said means for adjusting said amplitude adjusts said amplitude proportional to a square root of said ratio.

Claim 7

A vibratory material feeder as recited in claim 4 wherein said means for setting said desired rate comprises: means for generating a stream of pulses having a repetition frequency proportional to said desired rate.

Claim 8

A vibratory material feeder as recited in claim 6 further comprising: means for counting said pulses for a predetermined time to produce a setpoint count; and programmable means for normalizing said setpoint count.

Claim 9

A vibratory material feeder comprising: electromechanical vibratory actuator means for feeding material; drive means for applying a substantially sinusoidal electrical drive wave form to said actuator means; means for detecting a phase difference between a voltage and a current applied to said actuator means; and means, responsive to said phase difference, for controlling said drive means to minimize said phase difference whereby said actuator means is driven substantially in mechanical resonance, said means responsive to said phase difference comprising means for storing a representation of at least a portion of at least one substantially sinusoidal voltage wave form, and means for recalling said representation at a recalling frequency determined by said phase difference.

Claim 10

A vibratory material feeder comprising: electromechanical vibratory actuator means for feeding material; drive means for applying a substantially sinusoidal electrical drive wave form to said actuator means; means for detecting a phase difference between a voltage and a current applied to said actuator means; and means, responsive to said phase difference, for controlling said drive means to minimize said phase difference whereby said actuator means is driven substantially in mechanical resonance, said means responsive to said phase difference comprising means for storing a representation of at least a portion of at least one substantially sinusoidal voltage wave form, and means for recalling said representation at a recalling frequency determined by said phase difference.

Claim 11

A vibratory material feeder as recited in claim 8 wherein said means for storing comprises a programmable read only memory.

Claim 12

A vibratory material feeder as recited in claim 8 wherein said drive means comprises: means for applying a substantially sinusoidal voltage to said actuator means, said voltage having a frequency proportional to said recalling frequency.

Claim 13

A vibratory material feeder as recited in claim 10 wherein said means responsive to said phase difference further comprises: means for calculating said recalling frequency including means for increasing said recalling frequency if said phase difference indicates operation of said actuator means at a frequency below mechanical resonance, and means for decreasing said recalling frequency if said phase difference indicates operation of said actuator means at a frequency above mechanical resonance.

Claim 14

A vibratory material feeder as recited in claim 11 wherein said means for increasing increases said recalling frequency at a first rate if said phase difference indicates operation of said actuator means at a first frequency, and increases said recalling frequency at a second rate faster than said first rate if said phase difference indicates operation of said actuator means at a second frequency less than said first frequency.

Claim 15

A vibratory material feeder as recited in claim 11 wherein said means for decreasing decreases said recalling frequency at a first rate if said phase difference indicates operation of said actuator means at a first frequency, and decreases said recalling frequency at a second rate faster than said first rate if said phase difference indicates operation of said actuator means at a second frequency greater than said first frequency.

Claim 16

A vibratory material feeder comprising: means, including electromagnetic vibratory actuator means, for discharging material; means for driving said actuator means with a substantially sinusoidal electrical drive wave form; means for calculating a phase difference between a current passing through said actuator means and a voltage across said actuator means; means for calculating electrical power applied to said actuator means by said means for driving; means for storing a representation of at least a portion of at least one substantially sinusoidal wave form; means for recalling said representation at a recalling frequency to produce said electrical drive wave form; means for adjusting a frequency of said substantially sinusoidal electrical drive wave form to maintain said means for discharging substantially in mechanical resonance, including means for adjusting said recalling frequency responsive to said phase difference; and means for adjusting a magnitude of said substantially sinusoidal electrical drive wave form to discharge material from said means for discharing at a desired material discharge rate, including means for adjusting a magnitude of said representation responsive to calculated electrical power.

Claim 17

A vibratory material feeder comprising: means, including electromagnetic vibratory actuator means, for discharging material; means for driving said actuator means with a substantially sinusoidal electrical drive wave form; means for calculating a phase difference between a current passing through said actuator means and a voltage across said actuator means; means for calculating electrical power applied to said actuator means by said means for driving; means for storing a representation of at least a portion of at least one substantially sinusoidal wave form; means for recalling said representation at a recalling frequency to produce said electrical drive wave form; means for adjusting a frequency of said substantially sinusoidal electrical drive wave form to maintain said means for discharging substantially in mechanical resonance, including means for adjusting said recalling frequency responsive to said phase difference; and means for adjusting a magnitude of said substantially sinusoidal electrical drive wave form to discharge material from said means for discharing at a desired material discharge rate, including means for adjusting a magnitude of said representation responsive to calculated electrical power.