Algorithms and methods for controlling threading of pipe

Abstract

Various methods are described for forming threads in a workpiece, and particularly for controlling and/or monitoring threading of workpieces. Also described are tools and a system used in performing the methods.

1 . A method for forming threads in a workpiece using a tool including a tool head having at least one threading die, an electric motor rotatably powering the tool head, a sensor for measuring angular velocity of the tool, a controller for controlling operation of the motor, and memory provisions for saving angular velocity measurements, wherein the method comprises:
 rotating the tool head that includes at least one threading die, by use of the motor;   measuring angular velocity of the tool, by use of the sensor;   providing a measured angular velocity value to the controller;   adding the measured angular velocity value to a data set stored in the memory;   summing the stored angular velocity values within the data set to produce an angular velocity data set summation;   comparing the angular velocity data set summation to a first threshold;   if the first threshold has been met, discontinuing tool operation or braking tool rotation.   
     
     
         2 . The method of  claim 1  further comprising:
 determining if the data set is full when a maximum predetermined number of angular velocity values is reached; 
 if the data set is not full, performing the adding operation; 
 if the data set is full, removing an oldest angular velocity measurement from the data set and adding the newest angular velocity measurement. 
 
     
     
         3 . The method of  claim 1  wherein prior to rotating the tool head, the data set is emptied. 
     
     
         4 . The method of  claim 1  wherein a user actuates a tool trigger to begin rotating the tool head. 
     
     
         5 . The method of  claim 1  wherein the tool is a hand-held power drive tool. 
     
     
         6 . The method of  claim 1  wherein the sensor is a gyroscopic sensor. 
     
     
         7 . The method of  claim 1  wherein the controller includes at least one microprocessor. 
     
     
         8 . The method of  claim 1  wherein if the first threshold has not been met, the measuring, providing, adding, summing, and comparing operations are repeated. 
     
     
         9 . A tool for forming threads in a workpiece comprising:
 a tool head including a threading die;   a trigger to initiate activation of the tool;   an electrically powered motor and a powered rotary drive for rotatably powering the tool head;   a sensor for measuring angular velocity of the tool;   a controller for controlling operation of the motor and configuring an angular velocity data set;   a memory provision for storing angular velocity measurements;   wherein the sensor is configured to provide measurements of the angular velocity of the tool to the controller, the controller is configured to determine if an angular velocity data set has reached a predetermined maximum number of angular velocity measurements, the controller is further configured to sum the stored angular velocity values in the data set to produce a stored angular velocity summation, and the controller is further configured to compare the angular velocity summation to a first threshold and determine if the first threshold has been met.   
     
     
         10 . The tool of  claim 9  wherein the sensor is a gyroscopic sensor. 
     
     
         11 . The tool of  claim 9  further comprising:
 an electrical current sensor configured to measure electrical current draw or consumption by the motor. 
 
     
     
         12 . The tool of  claim 9  wherein the controller is a digital microcontroller. 
     
     
         13 . The tool of  claim 9  wherein the controller is configured to provide at least one of a counter of motor rotations, an angular velocity counter, and a timer. 
     
     
         14 . The tool of  claim 9  further comprising:
 an operator indicator. 
 
     
     
         15 . The tool of  claim 9  further comprising:
 a gearbox or transmission. 
 
     
     
         16 . The tool of  claim 9  wherein the controller is configured such that if the angular velocity data set has reached the maximum number of angular velocity measurements, the controller removes the oldest angular velocity measurement from the stored angular velocity data set. 
     
     
         17 . The tool of  claim 9  wherein the controller is configured such that if the angular velocity data set has not reached the maximum number of angular velocity measurements, the controller adds an angular velocity measurement from the sensor to the stored angular velocity data set. 
     
     
         18 . The tool of  claim 9  wherein the controller is configured such that if the first threshold has not been met, the sensor provides another angular velocity measurement to the controller. 
     
     
         19 . The tool of  claim 9  wherein the controller is configured such that if the first threshold has been met, the controller stops operation of the tool.