Saw guide pressure feed speed control systems and methods
OwnerWarren L. Myrfieldinventor
Life of this patent
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Abstract
A sawmill feedspeed control system having a force sensor operatively coupled to a sawguide of a sawblade, the output of the force sensor being processed and supplied to a motion controller and driver for reducing or increasing feed velocity of a workpiece so as to prevent overfeed or underfeed, while minimizing deviations of the blade from a straight cut and maximizing production throughput.
Claims34
An apparatus for detection of a deviation of a saw cut from a true cut line through a workpiece, which comprises:
- a) a bottom sawguide, said bottom sawguide having a front face and a second face, wherein said front face is enabled to contact and pre-strain a sawblade of a bandmill during a cut through a workpiece;
- and,
- b) a force sensor operatively coupled to said second face of said bottom sawguide, wherein said force sensor is enabled to sense a force associated with an incipient lateral deflection of a pre-stressed sawblade toward or away from said front face during a cut and to generate an electrical signal indicative of a magnitude and a direction in real time of said incipient lateral deflection from a true cut line.
The apparatus of claim 8, wherein said linkage comprises a load cell assembly, wherein said load cell assembly having a first end member rigidly attached at one end on a first side of said slot proximate to said mouth and a second end member rigidly attached at an opposite end on an opposite side of said slot proximate to said mouth, said load cell assembly further comprising a slot-straddling member disposed between said end members and a force sensor disposed between said slot-straddling member and one said end member, wherein said slot-straddling member is enabled to transfer any elastic compression or relaxation of said strain concentration slot to said force sensor.
A method for making a bandmill cut through a workpiece, said bandmill having a sawblade, a top sawguide and a bottom sawguide, each sawguide having a front face enabled to contact and pre-strain the sawblade for making a cut through a workpiece, a motion controller and a drive mechanism for controlling workpiece feedspeed;
- wherein said method is characterized by:
- (a) providing an anti-deviation feedback loop controller to an operator of a bandmill, said anti-deviation feedback loop controller comprising:
- i) a force sensor operatively coupled to a second face of said bottom sawguide, wherein said force sensor is enabled to sense a force associated with an incipient lateral deflection of said sawblade toward or away from said FRONT face of said bottom sawguide during a cut and to generate an electrical signal indicative of a magnitude and a direction of said incipient lateral deflection from a true cut line;
- ii) an anti-deviation control system configured to receive said electrical signal from said force sensor, and to determine a feedspeed adjustment output therefrom;
- iii) a motor drive mechanism enabled to receive said feedspeed adjustment output from said anti-deviation control system and drive a workpiece feedspeed in response thereto;
- (b) pre-stressing said blade by laterally displacing said bottom sawguide against said blade;
- and,
- (c) while cutting a workpiece, monitoring said electrical signal and operating said motion drive mechanism under control of said anti-deviation control system so as to counter any lateral deflection of said blade from a true cut line, thereby operating an anti-deviation feedback control loop.
An apparatus for controlling feedspeed of a saw cut through a workpiece, which comprises:
- a) a bottom sawguide, said bottom sawguide having a front face and a second face disposed thereon, wherein said front face is enabled to contact and pre-strain a sawblade of a bandmill for making a cut through a workpiece;
- b) a force sensor operatively coupled to said second face of said bottom sawguide, wherein said force sensor is enabled to sense a force associated with an incipient lateral deflection of a pre-stressed sawblade toward or away from said FRONT face during a cut and to generate an electrical signal indicative of a magnitude and a direction in real time of said incipient lateral deflection from a true cut line;
- c) an anti-deviation control system configured to receive said electrical signal from said force sensor and further to determine a corrective feedspeed adjustment output therefrom;
- and,
- d) a motor drive mechanism enabled to receive said feedspeed adjustment output from said anti-deviation control system and drive a workpiece feedspeed in response thereto.
Dependencies are inferred from the claim text.