Laundry water extractor speed limit control and method

Abstract

A method and apparatus for controlling the speed of an extractor measures an out of balance condition of the extractor and then sets the rotational speed to a preselected value. Higher out of balance values result in lower rotational speeds. Lower out of balance values result in higher rotational speeds. A preselected maximum rotational speed can be set on the controller.

1 . A method of limiting the extract speed of a clothes washing extractor, comprising the steps of:
 (a) mounting an accelerometer on the extractor;   (b) increasing the speed of the extractor over time;   (c) using the accelerometer to measure an out of balance condition of the extractor;   (d) adjusting the speed of the extractor corresponding to the amount of out of balance that is measured by the accelerometer in step “c”;   (e) wherein the rotational speed of the extractor is limited to a preselected value corresponding to a measured out of balance.   
   
   
       2 . The method of  claim 1 , wherein the accelerometer generates an output voltage that is measured, said output voltage being a function of the amount of out of balance of step “c”. 
   
   
       3 . The method of  claim 1 , wherein in step “d” a plurality of different speed limit threshold inputs correspond to different measured out of balance conditions of step “c”. 
   
   
       4 . The method of  claim 1 , wherein the accelerometer measures out of balance conditions of between about 60 and 80 percent of a rated capacity of the extractor. 
   
   
       5 . The method of  claim 1 , wherein the speed limit threshold input varies between about 800 and 1,000 revolutions per minute. 
   
   
       6 . The method of  claim 1 , wherein the speed of the extractor is not limited when the accelerometer measures little or no out of balance. 
   
   
       7 . The method of  claim 1 , wherein the speed of the extractor is limited to no more than about 80 percent of maximum speed when the accelerometer measures a predetermined maximum allowable out of balance. 
   
   
       8 . The method of  claim 1 , wherein in step “d” a first controller receives input from the accelerometer and signals a second controller to control the speed of the extractor. 
   
   
       9 . The method of  claim 1 , wherein the extractor includes a frame and step “a” included mounting the accelerometer on the frame. 
   
   
       10 . The method of  claim 1 , wherein the controller continuously compares the out of balance value generated by the accelerometer with the rotational speed of the rotary extractor. 
   
   
       11 . A laundry water extractor speed limit control, comprising:
 a) a machine frame that includes a rotary extractor;   b) an accelerometer mounted to the machine frame;   c) a controller that receives input from the accelerometer, said input indicating an out of balance value for the rotary extractor;   d) wherein the controller varies the rotational speed of the rotary extractor with varying input from the accelerometer, the rotational speed being greater for a lower out of balance value and the rotational speed being lower for a greater out of balance value.   
   
   
       12 . The laundry water extractor speed limit control of  claim 11 , wherein the accelerometer generates input on the form of varying voltages corresponding to varying out of balance values. 
   
   
       13 . The laundry water extractor speed limit control of  claim 11 , wherein the accelerometer continuously monitors out of balance values. 
   
   
       14 . The laundry water extractor speed limit control of  claim 11 , wherein the controller enables a continuous comparison of the out of balance value generated by the accelerometer versus the rotational speed of the rotary extractor. 
   
   
       15 . The laundry water extractor speed limit control of  claim 14 , wherein the controller prevents acceleration of the rotary extractor when a preset rotational speed is reached for a given out of balance value. 
   
   
       16 . The laundry water extractor speed limit control of  claim 11 , wherein the extractor is driven by an inverter, and the controller includes a processor that senses when the accelerometer exceeds a preset threshold value for out of balance. 
   
   
       17 . The laundry water extractor speed limit control of  claim 16 , wherein the processor is in communication with the inverter so that it is able to signal the inverter to limit rotational speed of the extractor when the accelerometer exceeds a preset threshold value for out of balance. 
   
   
       18 . The laundry water extractor speed limit control of  claim 11 , wherein the input from the accelerometer is voltage and the voltage input generated by the accelerometer communicates to the controller which then controls the speed of the rotary extractor. 
   
   
       19 . The laundry water extractor speed limit control of  claim 11 , wherein for a given out of balance of the rotary extractor, the voltage generated by the accelerometer is a value that is in between about 2.60 and 3.35 VDC. 
   
   
       20 . The laundry water extractor speed limit control of  claim 11 , wherein during at least some time interval that the rotary extractor rotates, the voltage generated by the accelerometer is a value that is in between about 2.60 and 3.35 VDC. 
   
   
       21 . A clothes washing extractor system comprising:
 (a) an cabinet;   (b) a drum rotationally mounted to the cabinet;   (c) a motor operative connected to the drum, the motor capable of rotating the drum at a plurality of different speeds;   (d) a vibration sensor for measuring a predetermined out of balance condition of the extractor;   (e) a controller operatively connected to both the vibration sensor and the motor, the controller continuously adjusting the rotational speed of the motor until the vibration sensor indicates that an the out of balance condition detected by the vibration sensor is in an acceptable range of out of balance.   
   
   
       22 . The clothes washing extractor of  claim 21 , wherein the vibration sensor comprises an accelerometer. 
   
   
       23 . A method of controlling the extract speed of a clothes washing extractor, comprising the steps of:
 (a) mounting a vibration sensor on the extractor;   (b) increasing the speed of the extractor over time;   (c) using the vibration sensor to measure an out of balance condition of the extractor;   (d) adjusting the speed of the extractor corresponding to the amount of out of balance that is measured by the accelerometer in step “c”;   (e) wherein the rotational speed of the extractor is limited to a preselected value corresponding to a measured out of balance.   
   
   
       24 . The method of  claim 23 , wherein in step “d” the speed of the extractor is increased for a first period of time, decreased for a second period of time, increased for a third period of time, and remains constant for a fourth period of time, the first, second, third, and fourth periods of time occurring in the order as numbered. 
   
   
       25 . The method of  claim 23 , wherein in step “a” the vibration sensor comprises an accelerometer.