Claims
- 1. A method of controlling product flow in a product delivery system including an electromechanical vibratory conveyor which includes a product conveying member, comprising
vibrating the product conveying member to move products from one position to another position while
controlling the vibration of the product conveying member both statically and dynamically.
- 2. The method according to claim 1 wherein the vibration of the product conveying member is controlled by an initial coarse tuning followed by a fine tuning of the resonance frequency.
- 3. The method according to claim 2 wherein said coarse tuning includes fixing the amplitude of the vibration to a preprogrammed or production adjusted value.
- 4. The method according to claim 3 wherein said coarse tuning includes changing the frequency from 65 to 35 hertz in decrements of one hertz while recording feed-back values to determine the frequency of the peak value of the feed-back as a coarse tuned frequency, and saving that coarse tuned frequency as a program parameter.
- 5. The method according to claim 2 wherein said fine tuning includes setting the vibrating frequency to a coarse frequency plus one hertz, decrementing the coarse frequency plus one hertz to the coarse frequency minus one hertz in small decrements while recording feed-back values to determine the frequency of the peak value of the feed-back as a fine tuned frequency and saving that fine tuned frequency as a program parameter.
- 6. The method according to claim 5 including optimizing the amplitude by setting the vibrating frequency to the fine tuned frequency, changing the amplitude incrementally or decrementally by small amounts to maximize the displacement of said product conveying member without hammering and saving that amplitude setting as a program parameter.
- 7. The method according to claim 1 wherein controlling the vibration of said product conveying member includes sensing the displacement of said product conveying member during vibration thereof and changing the frequency of vibration until maximum displacement at a fixed amplitude is achieved.
- 8. The method according to claim 1 wherein controlling the vibration of the product conveying member includes sensing the weight of product on the product conveying member, comparing the sensed weight with a predetermined target weight and increasing or decreasing the frequency of vibration by a small amount if the sensed weight is different from the target weight by an amount greater than a permissible delta.
- 9. The method according to claim 8 wherein the weight of product is sensed several times over a predetermined period of time, an averaged sensed weight is determined and the average sensed weight is compared to the predetermined target weight.
- 10. The method according to claim 8 wherein the frequency of vibration is increased or decreased by one-tenth of a hertz.
- 11. A product delivery system comprising an electromechanical vibratory conveyor including
a product conveying member mounted for vibratory movement, means for vibrating said product conveying member at an amplitude and resource frequency, and means for controlling the vibration of said product conveying member both statically and dynamically to optimize performance of said vibrating means both with and without product on said product conveying member.
- 12. A product delivery system according to claim 11 wherein said vibration controlling means controls the vibration of said product conveying member by adjusting the frequency of said vibrating means to achieve maximum displacement of said product conveying member at a fixed amplitude with no product on said product conveying member.
- 13. A product delivery system according to claim 12 wherein said vibration controlling means adjusts the frequency of said vibrating means to achieve maximum displacement of said product conveying member at a fixed amplitude with product on said product conveying member.
- 14. A product delivery system according to claim 11 wherein said vibration control means includes means for measuring the displacement of said product conveying member and means for changing the frequency of vibration until maximum displacement of said product conveying member at a fixed amplitude is achieved both without and with product on said product conveying member.
- 15. A product delivery system according to claim 14 wherein said displacement measuring means comprises a non-contact inductive proximity sensor.
- 16. A product delivery system according to claim 14 wherein said displacement measuring means comprises means for determining back emf of said vibrating means and means for generating a signal proportional to the displacement of said product conveying member based on said back emf.
- 17. A product delivery system according to claim 11 wherein said vibrating means includes a coil wound on a core operatively associated with an armature attached to said product conveying member, and a bipolar power supply for driving said coil.
- 18. A product delivery system according to claim 17 wherein said bipolar power supply includes a pulse width modulated drive circuit including two switches connected in series to a differential power supply with said coil connected to center connection of said two switches and supply ground to provide pulse width modulated differential energy to said coil and discharge paths for the energy stored to the supply to reduce core saturation and improve efficiency and accuracy.
- 19. A product delivery system according to claim 18 wherein said pulse width modulated drive circuit includes a single flip-flop to insure no direct shorts will occur if both switches are turned on simultaneously.
- 20. A product delivery system according to claim 18 wherein said pulse width modulated drive circuit utilizes a dual signal to drive said switches which simultaneously turns one switch on and disables the other switch.
- 21. A product delivery system according to claim 18 wherein said pulse width modulated drive circuit optically isolates switch command signals from high voltage drive signals to said switches.
- 22. A product delivery system according to claim 18 wherein said bipolar supply includes main power lines and wherein said pulse width modulated drive circuit derives logic voltage to control said switches from said main power lines.
- 23. A product delivery system according to claim 18 wherein said pulse width modulated drive circuit includes enable gating circuitry and disable gating circuitry on each of said switches to guarantee that both switches are never activated simultaneously.
- 24. A product delivery system according to claim 23 wherein said gating circuitry is disabled until power supplied to both of said switches has reached a minimum level.
- 25. A product delivery system according to claim 23 wherein said gating circuitry is disabled if the line generated logic supply voltage falls below a preset limit.
- 26. A product delivery system according to claim 18 wherein said pulse width modulated drive circuit includes means for detecting the current level in said drive circuit and for disabling said switches if the current level exceeds a preset level.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on U.S. Provisional Application No. 60/287,183 filed Apr. 27, 2001, which is incorporated herein in its entirety by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60287183 |
Apr 2001 |
US |