Machine tool window

Abstract

A machine tool window is provided with an apparatus for ultrasonically clearing droplets of cutting fluid from the window. The apparatus comprises a one or more transducers ( 200, 210 ) coupled to the window. Each of the one or more transducers is operable to at any selected one of a plurality of different frequencies to generate respective wave-types. A frequency generator ( 925 ) is operable to provide ultrasonic drive signals ( 926 ) to the transducers for the plurality of different frequencies. A mode controller ( 930 ) controls the generator ( 925 ) and transducer ( 200 ) to apply to the window ultrasonic waves of any selected frequency and wave type from the plurality of different frequencies and wave-types.

What is claimed is: 
     
         1 . A system comprising a machine tool window and an apparatus for clearing droplets of cutting fluid from the machine tool window, the apparatus comprising:
 one or more transducers coupled to the machine tool window, each of the one or more transducers being configured to generate ultrasonic waves in the machine tool window; and   a generator for providing ultrasonic drive signals to the one or more transducers to generate the ultrasonic waves to ultrasonically clear the droplets of cutting fluid from the machine tool window.   
     
     
         2 . A system according to  claim 1 , wherein each of the one or more transducers is configured to generate the ultrasonic waves in the machine tool window at any selected one of a plurality of different frequencies and wave-types,
 wherein the generator is configured to provide the ultrasonic drive signals to the one or more transducers to generate the ultrasonic waves at the any selected one of the plurality of different frequencies and wave-types; and   further comprising a mode controller for controlling at least one of the generator and the one or more transducers to generate the ultrasonic waves at the any selected one of the plurality of different frequencies and wave-types.   
     
     
         3 . A system according to  claim 2 , wherein each of the one or more transducers comprises a plurality of electrodes, and the mode controller is configured to select different sets of the plurality of electrodes for each of the one or more transducers to generate ultrasonic waves of different frequencies and wave types. 
     
     
         4 . A system according to  claim 3 , wherein the mode controller comprises a mode selector for selecting a frequency and wave type and a switching circuit for selecting the different sets of the plurality of electrodes. 
     
     
         5 . An apparatus according to  claim 3 , wherein the mode controller is configured to control each of the one or more transducers to operate at a particular frequency by selecting a particular set of electrodes which are spaced apart by a distance dependent on a wavelength of a wave of that particular frequency. 
     
     
         6 . A system according to  claim 2 , wherein the mode controller is configured to control the generator and the one or more transducers to produce waves with frequencies in the range 200 kHz to 4 MHz. 
     
     
         7 . A system according to  claim 2 , wherein the mode controller is configured to control the generator and the one or more transducers to produce waves with frequencies in the range of 1 MHz to 2.5 MHz. 
     
     
         8 . A system according to  claim 2 , wherein the mode controller is configured to control the generator and the one or more transducers to produce waves with frequencies in the range of 100 kHz to 1 MHz. 
     
     
         9 . A system according to  claim 2 , wherein the mode controller is configured to control the one or more transducers and generator to successively operate at different ones of a plurality of the selected frequencies and wave types. 
     
     
         10 . A system according to  claim 9 , wherein the mode controller is configured to change from one configuration of the generator and the one or more transducers to another with a time delay between the configurations. 
     
     
         11 . A system according to  claim 2 , further comprising:
 a control system, having a detector configured to sense ultrasonic waves emitted by at least one of the one or more transducers for detecting an amount of wave attenuation on the machine tool window,   wherein the mode controller is configured to control the generator and the one or more transducers based on the detected amount of wave attenuation.   
     
     
         12 . A system according to  claim 1 , wherein the generator is configured to apply the ultrasonic drive signals to the one or more transducers in pulses. 
     
     
         13 . A system according to  claim 1 , wherein the machine tool window is coated on a surface which, in operation, is inside a machine tool with a coating which is configured to repel cutting fluid. 
     
     
         14 . A system according to  claim 1 , further comprising a machine tool. 
     
     
         15 . A method of clearing cutting fluid from a window of a machine tool, the method comprising generating ultrasonic waves in the window using one or more ultrasonic transducers coupled to the window.