Hair curler with adjustable torque

Abstract

A hair curler with adjustable torque includes a working portion for connected with a hair roller, a driving device for driving the working portion to rotate, a circuit board for controlling the driving device, a control portion connected with the circuit board to make the driving device drive the working portion to rotate via the circuit board, a torque detecting device connected to the working portion to detect the torque of the working portion and to send it to the circuit board, a torque display device connected with the torque detecting device for displaying the value of torque, a torque setting portion connected with the circuit board for setting a predetermined torque. When the detected torque reaches the predetermined value, the circuit board makes the driving device drive the working portion to stop rotating so as to prevent hair from over-rotated.

What is claimed is: 
     
         1 . A hair curler with adjustable torque, including:
 a working portion, for being disposed with a hair roller;   a driving device, driving the working portion to rotate via a decelerating device;   a circuit board, controlling the driving device;   a control portion, connected with the circuit board to control the driving portion to drive the working portion to rotate about a first direction, about a reverse second direction, or stop rotating;   a torque detecting device, connected with the working portion to detect a torque of the working portion about the first direction and to send a value of the torque detected to the circuit board;   a torque display device, connected with the torque detecting device to display a value of the torque detected by the torque detecting device;   a torque setting portion, connected with the circuit board to set off a predetermined value of torque, the circuit board triggering the driving device to drive the working portion to stop rotating about the first direction when a value of torque about the first direction received by the circuit board from the torque detecting device reaches the predetermined value of torque.   
     
     
         2 . The hair curler with adjustable torque of  claim 1 , wherein the torque setting portion includes a setting button and a display device, the predetermined value of torque is adjustable by pressing the setting button, the predetermined value of torque is shown on the display device. 
     
     
         3 . The hair curler with adjustable torque of  claim 1 , wherein the torque display device includes a plurality of LED lights, a number of the LED lights which are on is proportional to the value of torque detected by the torque detecting device. 
     
     
         4 . The hair curler with adjustable torque of  claim 1 , wherein the working portion has a constant rotating speed. 
     
     
         5 . The hair curler with adjustable torque of  claim 1 , further includes a hair roller, the hair roller being coaxially disposed on the working portion and including a plurality of shells and a pressing element, the shells being arranged around an axial direction, each shell being formed with a recess on an inner wall thereof, the recesses forming a conical space, the pressing element being located in the conical space and being linked up with the working portion, the pressing element moving in the conical space along the axial direction to make the shells move away from each other so as to expand an outer diameter of the hair roller when the working portion rotates about the first direction, the pressing element moving toward an opposite direction to make the shells move toward each other so as to reduce the outer diameter of the hair roller when the working portion rotates about the second direction. 
     
     
         6 . The hair curler with adjustable torque of  claim 5 , wherein the hair roller further includes at least one elastic ring, the shells are formed with annular grooves on outer surfaces thereof for the elastic ring to be embedded in, the elastic ring makes the shells tend to move toward each other. 
     
     
         7 . The hair curler with adjustable torque of  claim 5 , further including an outer cover for being disposed outside the hair roller, the outer cover including two clamping elements which are pivotally connected to each other, a gap being formed between the two clamping elements at an end of the outer cover opposite to a pivot axis of the two clamping elements, each clamping element being bending and arc-shaped, an adjusting piece being detachably disposed on the clamping elements near the pivot axis, the two clamping elements being able to pivot a larger angle to make a maximum width of the gap larger when the adjusting piece is removed, the two clamping elements being able to pivot a smaller angle to make a maximum width of the gap smaller when the adjusting piece has a larger length. 
     
     
         8 . The hair curler with adjustable torque of  claim 1 , wherein the control portion includes a rocker switch having a rotation switch and a reverse rotation switch at two opposite ends thereof, a power supply is switched on when the rocker switch is long pressed, the working portion is driven to rotate about the first direction until the value of torque detected by the torque detecting device reaches the predetermined value of torque when the rotation switch is pressed, the working portion is driven to rotate about the second direction when the reverse rotation switch is continuously pressed.