Claims
- 1. An apparatus for variably controlling the feed rate of material to be cut by a saw having a saw blade and a wearable guide block, said apparatus comprising:
means for establishing a zero reference point for the lateral position of the saw blade; means for detecting lateral movement of the saw blade away from the zero reference point when the saw blade is cutting material being fed into the saw blade; means for generating a signal proportional to the detected lateral movement of the saw blade; means for establishing a reference signal proportional to the proportional signal generated at a preselected acceptable lateral movement of the saw blade; means for controlling feed rate of the material; means for comparing the generated signal to the reference signal, wherein if the generated signal is less than the reference signal, then the means for controlling the feed rate of the material continuously increases the feed rate, wherein if the generated signal is greater than the reference signal, then the means for controlling the feed rate of material continuously decreases the feed rate; and means for automatically and periodically reestablishing a zero reference point to compensate for guide block wear and build up.
- 2. The apparatus of claim 1 wherein the rate at which the feed rate is continuously increased and decreased by the means for controlling the feed rate of the material is predetermined.
- 3. The apparatus of claim 1 further comprising:
a means for generating a comparative signal for generating a comparative signal proportional to the difference between the generated signal and the reference signal; wherein the means for controlling the feed rate of material continuously increases the feed rate at a rate proportional to the comparative signal if the generated signal is less than the reference signal, and wherein if the generated signal is greater than the reference signal, then the means for controlling the feed rate of material continuously decreases the feed rate at a rate proportional to the comparative signal.
- 4. The apparatus of claim 1 wherein the means for establishing a zero reference point for the lateral position of the saw blade further comprises:
means for detecting the location of the saw blade when it is not engaged in sawing material to establish an initial zero reference point; means for generating an initial lateral position proportional to the initial position of the saw blade; means for again detecting an updated location of the saw blade when it is not engaged in sawing material; means for generating an updated lateral position signal proportional to the position of the saw blade when not engaged in work; and means for resetting the zero reference point to conform to the updated lateral position signal.
- 5. The apparatus of claim 1 further comprising:
means for detecting lateral movement of the saw blade when said cut material is being withdrawn from the saw blade; and means for comparing the generated signal when the cut material is being withdrawn from the saw blade to the reference signal, wherein if the generated signal is less than the reference signal, then the means for controlling the feed rate of the material continuously increases the withdrawal rate, and wherein if the generated signal is greater than the reference signal, then the means for controlling the feed rate of the material continuously decreases the withdrawal rate.
- 6. The apparatus of claim 5 wherein the means for establishing a zero reference point for the lateral position of the saw blade further comprises:
means for detecting the location of the saw blade when it is not engaged in sawing material to establish an initial zero reference point; means for generating an initial lateral position proportional to the initial position of the saw blade; means for again detecting an updated location of the saw blade when it is not engaged in sawing material; means for generating an updated lateral position signal proportional to the position of the saw blade when not engaged in work; and means for resetting the zero reference point to conform to the updated lateral position signal.
- 7. The apparatus of claim 1 wherein the means for detecting lateral movement of the saw blade away from the zero reference point when the saw blade is cutting material being fed into the saw blade is a proximity sensor positioned adjacent to said saw blade for generating a signal related to the position of said saw blade relative to said proximity sensor.
- 8. The apparatus of claim 1 wherein the means for automatically and periodically reestablishing a zero reference point to compensate for guide block wear further comprises means for determining the position of the saw blade when not sawing material to reestablish the zero reference point.
- 9. The apparatus of claim 1 wherein the means for automatically and periodically reestablishing a zero reference point to compensate for guide block wear further comprises means for sampling said proportional signal generated by said proximity sensor when said saw blade is not sawing material and means for periodically averaging two or more of said samples of said proportional signal generated by said proximity sensor to reestablish said zero reference point.
- 10. An apparatus for variably controlling the feed rate of material to be cut by a saw having a saw blade and a wearable guide block, said apparatus comprising:
means for establishing a zero reference point for the lateral position of the saw blade by determining the saw blade position prior to sawing material; means for detecting lateral movement of the saw blade away from the zero reference point when the saw blade is cutting material being fed into the saw blade; means for generating a blade motion signal proportional to the detected lateral movement of the saw blade; means for establishing a first reference signal proportional to the blade motion signal generated at a preselected acceptable lateral movement of the saw blade; means for generating a second reference signal proportional to the blade motion signal generated at a first level of unacceptable lateral movement of the saw blade; means for controlling feed rate of the material; means for comparing the blade motion signal to the first and second reference signals, wherein if the blade motion signal is less than the first reference signal, then the means for controlling the feed rate of the material continuously increases the feed rate, wherein if the blade motion signal is greater than the first reference signal and less than the second reference signal, then the means for controlling the feed rate of material neither increases nor decreases the feed rate, and if the blade motion signal is greater than the second reference signal, then the means for controlling the feed rate of material continuously decreases the feed rate; and means for automatically and periodically reestablishing a zero reference point to compensate for guide block wear and build up.
- 11. The apparatus of claim 10 wherein the rate at which the feed rate is continuously increased and decreased by the means for controlling the feed rate of the material is predetermined.
- 12. The apparatus of claim 10 further comprising:
a means for generating a comparative signal proportional to the difference between the generated signal and the reference signal; wherein the means for controlling the feed rate of material continuously increases the feed rate at a rate proportional to the comparative signal if the generated signal is less than the reference signal, and wherein if the generated signal is greater than the reference signal, then the means for controlling the feed rate of material continuously decreases the feed rate at a rate proportional to the comparative signal.
- 13. The apparatus of claim 10 wherein the means for detecting lateral movement of said saw blade away from the zero reference point when said saw blade is cutting material being fed into said saw blade is a proximity sensor positioned adjacent to said saw blade, wherein said proximity sensor generates a signal related to the position of said saw blade relative to said proximity sensor.
- 14. The apparatus of claim 10 wherein the means for automatically and periodically reestablishing a zero reference point to compensate for guide block wear further comprises means for determining the position of the saw blade when not sawing material to reestablish the zero reference point.
- 15. The apparatus of claim 10 wherein the means for automatically and periodically reestablishing a zero reference point to compensate for guide block wear further comprises means for sampling said proportional signal generated by said proximity sensor when said saw blade is not sawing material and means for periodically averaging two or more of said samples of said proportional signal generated by said proximity sensor to reestablish said zero reference point.
- 16. An apparatus for variably controlling the feed rate of material to be cut by a saw having a saw blade and a wearable guide block, said apparatus comprising:
means for establishing a zero reference point for the lateral position of the saw blade by determining the saw blade position prior to sawing material; means for detecting lateral movement of the saw blade away from the zero reference point when the saw blade is cutting material being fed into the saw blade; means for generating a blade motion signal proportional to the detected lateral movement of the saw blade over a preselected period of time; means for establishing a first reference signal proportional to the blade motion signal generated at a preselected acceptable lateral movement of the saw blade; means for generating a second reference signal proportional to the blade motion signal generated at a first level of unacceptable lateral movement of the saw blade; means for controlling feed rate of the material; and means for comparing the blade motion signal to the first and second reference signals, wherein if the blade motion signal is less than the first reference signal, then the means for controlling the feed rate of the material continuously increases the feed rate, and wherein if the blade motion signal is greater than the second reference signal, then the means for controlling the feed rate of material continuously decreases the feed rate.
- 17. The apparatus of claim 16 wherein the rate at which the feed rate is continuously increased and decreased by the means for controlling the feed rate of the material is predetermined.
- 18. The apparatus of claim 16 further comprising:
means for generating a comparative signal proportional to the difference between the generated signal and the zero reference point, wherein if the generated signal is less than the zero reference point, then the means for controlling the feed rate of the material continuously increases the feed rate at a rate proportional to the comparative signal, and wherein if the generated signal is greater than the zero reference point, then the means for controlling the feed rate of the material continuously decreases the feed rate at a rate proportional to the comparative signal.
- 19. The apparatus of claim 16 which further comprises:
means for generating a third reference signal proportional to the blade motion signal generated at a second, greater level of unacceptable lateral movement of the saw blade than that of said second reference signal; and wherein if the blade motion signal is greater than the third reference signal, then the means for controlling the feed rate of the material reduces the feed rate to zero.
REFERENCE TO RELATED APPLICATION:
[0001] This application is a divisional of application Ser. No. 08/966,456, filed Nov. 07, 1997, Method for Variably Controlling Work Feed Rate for Cutting Wood, Metal and other Materials. The '456 application have been allowed but has not issued. This application is filed pursuant to 35 USC § 120 and 37 C.F.R. 1.53(b).
Divisions (1)
|
Number |
Date |
Country |
Parent |
08966456 |
Nov 1997 |
US |
Child |
09545967 |
Apr 2000 |
US |