Abrasive Disk, Hand-Held Power Tool and Control Method

Abstract

An abrasive disk has one or more layers in which abrasive grains are embedded. Embedded in one layer is a sensor for detecting an original periphery of the abrasive disk that has been altered by wear. The sensor has at least one closed conductor loop which is arranged at a radial distance from the original periphery such that, when the original periphery is worn by more than the radial distance, the conductor loop is interrupted. A transponder emits a radio signal indicative of whether the conductor loop is closed or interrupted.

1 .- 14 . (canceled) 
     
     
         15 . An abrasive disk, comprising:
 a first layer;   a sensor embedded in the first layer, wherein an original periphery of the abrasive disk is detectable by the sensor;   wherein the sensor has a first closed conductor loop which is disposed at a first radial distance from the original periphery such that when the original periphery is worn by more than the first radial distance the first closed conductor loop is interrupted; and   a transponder, wherein a radio signal is emittable by the transponder which is indicative of whether the first closed conductor loop is closed or interrupted.   
     
     
         16 . The abrasive disk as claimed in  claim 15 , wherein the sensor has a second closed conductor loop which is disposed at a second radial distance from the original periphery that is greater than the first radial distance and wherein the radio signal is indicative of which one of the first closed conductor loop and the second closed conductor loop is interrupted. 
     
     
         17 . The abrasive disk as claimed in  claim 16 , wherein the first closed conductor loop and the second closed conductor loop have a different radial extent. 
     
     
         18 . The abrasive disk as claimed in  claim 16 , wherein the first closed conductor loop and the second closed conductor loop have a different length. 
     
     
         19 . The abrasive disk as claimed in  claim 16 , wherein the first closed conductor loop and the second closed conductor loop have a different electromagnetic resonant frequency. 
     
     
         20 . The abrasive disk as claimed in  claim 16 , wherein the first closed conductor loop, the second closed conductor loop, and the transponder are printed on a film. 
     
     
         21 . The abrasive disk as claimed in  claim 15 , wherein the sensor has a memory integrated in the sensor in which a measure of a maximum permissible rotational speed of the abrasive disk is stored in dependence on the first closed conductor loop when severed and wherein the measure of the maximum permissible rotational speed is includable in the radio signal. 
     
     
         22 . The abrasive disk as claimed in  claim 15 , wherein the sensor and the transponder are integrated in a radio-frequency identification (RFID) chip. 
     
     
         23 . A hand-held power tool, comprising:
 the abrasive disk as claimed in  claim 15 ;   a holder, wherein the holder holds the abrasive disk;   an electric motor for rotating the abrasive disk;   a speed control for the electric motor;   a communication device, wherein a radio signal emitted by the transponder of the abrasive disk is receivable by the communication device; and   a device controller, wherein a speed for the speed control is settable based on a received radio signal.   
     
     
         24 . The hand-held power tool as claimed in  claim 23 , wherein the device controller sets a nominal speed if the communication device does not receive a radio signal. 
     
     
         25 . The hand-held power tool as claimed in  claim 23  further comprising a memory in which a measure of a maximum permissible rotational speed of the abrasive disk is stored. 
     
     
         26 . The hand-held power tool as claimed in  claim 25 , wherein the device controller reads out a list of maximum permissible rotational speeds of the abrasive disk stored in the memory. 
     
     
         27 . A control method for the hand-held power tool as claimed in  claim 23 , comprising the steps of:
 sending a first inquiry concerning a state of wear of the abrasive disk; and   adjusting a rotational speed of the abrasive disk based on a received radio signal.   
     
     
         28 . The control method for the hand-held power tool as claimed in  claim 27 , further comprising the steps of:
 sending a second inquiry concerning a maximum rotational speed of the abrasive disk which is indicative of a degree of wear of the abrasive disk and which is stored in a memory of the hand-held power tool; and   adjusting the rotational speed of the abrasive disk based on a response to the second inquiry.   
     
     
         29 . The abrasive disk as claimed in  claim 15  further comprising a second layer disposed adjacent to the first layer wherein abrasive grains are embedded in the second layer. 
     
     
         30 . The abrasive disk as claimed in  claim 15  wherein abrasive grains are embedded in the first layer.