Sander providing airflow correction

Abstract

A sander capable of correcting airflow amount comprises a body and a correction valve. The body includes an air intake passage to receive pressurized air, a drive motor driven by the pressurized air to rotate at a rotational speed including a preset range and an excessive range, and a regulation valve located on the air intake passage to adjust the rotational speed of the drive motor in the preset range. The correction valve includes an adjustment portion operable in an adjustment displacement and a mask wall movable by the adjustment portion to block the air intake passage. The adjustment portion determines the flow amount of the pressurized air passing through the correction valve according to the adjustment displacement thereof to confine the rotational speed of the drive motor from the excessive range to the preset range, thereby controls the rotational speed of the drive motor in the preset range.

What is claimed is: 
     
         1 . A sander providing airflow correction, comprising:
 a body including an air intake passage to receive pressurized air, a drive motor driven by the pressurized air to rotate at a rotational speed including a preset range and an excessive range, and a regulation valve located on the air intake passage and operable manually by a user to adjust the rotational speed of the drive motor in the preset range; and   a correction valve which is located on the air intake passage and coupled with the regulation valve, and includes an adjustment portion operable by a mechanical tool to proceed an adjustment displacement and a mask wall movable by the adjustment portion to block the air intake passage, the adjustment portion determining flow amount of the pressurized air passing through the correction valve according to the position thereof during the adjustment displacement to confine the rotational speed of the drive motor from the excessive range to the preset range.   
     
     
         2 . The sander of  claim 1 , wherein the proportion of the excessive range to the preset range is less than 30%. 
     
     
         3 . The sander of  claim 1 , wherein the air intake passage includes a positioning notch to hold the correction valve. 
     
     
         4 . The sander of  claim 3 , wherein the correction valve is fixedly held in the positioning notch through a clip ring. 
     
     
         5 . The sander of  claim 1 , wherein the mask wall includes an airflow directing hole to allow the pressurized air to pass through. 
     
     
         6 . The sander of  claim 1 , wherein the body includes an activation valve stem located on the air intake passage, the air intake passage including an air nozzle to block the pressurized air from entering the regulation valve, the activation valve stem being depressible to drive the air nozzle to deviate so that the pressurized air passes through the regulation valve. 
     
     
         7 . The sander of  claim 6 , wherein the body includes an activation member which butts the activation valve stem and is depressible to move the activation valve stem downwards so that the air nozzle is deviated against the regulation valve. 
     
     
         8 . The sander of  claim 1 , wherein the body includes a sanding disk driven by the drive motor to rotate in a rotational displacement. 
     
     
         9 . The sander of  claim 1 , wherein the regulation valve includes a control portion operable manually by the user, a throttle wall extended from the control portion to the air intake passage and operable by the user to determine degree of masking the air intake passage, and an airflow regulation port formed on the throttle wall to allow the pressurized air to pass through. 
     
     
         10 . The sander of  claim 1 , wherein the air intake passage includes an air intake duct to direct the pressurized air into the regulation valve, the correction valve being located between the regulation valve and the drive motor to transmit the pressurized air from the regulation valve to the drive motor.