Device for non-contact object handling

Abstract

A non-contact handling tool ( 8 ) for picking up an object ( 3 ), the tool comprising an ultrasonic transducer ( 10 ) extending between a reflective side and a picking side configured to emit ultrasounds forming, in a near field area of the picking side, an excess-pressure wave, and a fluid suction system configured to suction a fluid towards the picking side, forming in said near field area an under-pressure. The fluid suction system comprises at least a fluid suction channel ( 30 ) disposed in the ultrasonic transducer. The transducer has a height defined between the picking side and the reflective side corresponding to a half wavelength of the ultrasounds generated in the transducer.

1 . A non-contact handling tool ( 8 ) for picking up an object ( 3 ), the tool comprising an ultrasonic transducer ( 10 ) extending between a reflective side and a picking side configured to emit ultrasounds forming, in a near field area of the picking side, an excess-pressure wave and a fluid suction system configured to suction a fluid towards the picking side, forming in said near field area an under-pressure, characterised in that the fluid suction system comprises at least a fluid suction channel ( 30 ) disposed in the ultrasonic transducer, and in that the transducer has a height (h) defined between the picking side and the reflective side located within a range of 80% to 140% of a half wavelength λ/2 of the ultrasounds generated in the transducer. 
     
     
         2 . The non-contact handling tool according to  claim 1  characterised in that said height is less than 90 mm. 
     
     
         3 . The non-contact handling tool according to  claim 1  or  2 , characterised in that the suction channel comprises one or several suction nozzle(s) opening onto the picking side. 
     
     
         4 . The non-contact handling tool according to the preceding claim, characterised in that the suction channel comprises a suction nozzle opening onto the picking side, said suction nozzle being centred on the picking side. 
     
     
         5 . The non-contact handling tool according to the preceding claim, characterised in that the suction channel comprises several suction nozzles opening onto the picking side. 
     
     
         6 . The non-contact handling tool according to any of the preceding claims, characterised in that said at least one suction channel crosses the handling tool from the picking side to the reflective side. 
     
     
         7 . The non-contact handling tool according to any of the preceding claims characterised in that the ultrasonic transducer comprises an ultrasonic generator ( 12 ) and an ultrasonic transmission device ( 18 ) coupled to the generator, the transmission device comprising a front body ( 24 ) fitted with a tool securing member ( 24   b ) arranged at a nodal plane of the ultrasonic waves generated in the transducer. 
     
     
         8 . The non-contact handling tool according to the preceding claim characterised in that the transmission device comprises a rear body ( 22 ) and a biasing member ( 20 ), the ultrasonic generator being compressed between the front body and the rear body by the biasing member. 
     
     
         9 . The non-contact handling tool according to the preceding claim characterised in that the biasing member is a bolt, the suction channel extending through the bolt. 
     
     
         10 . The non-contact handling tool according to any of the two preceding claims characterised in that the ultrasonic generator comprises a stacking of a plurality of piezoelectric rings ( 14 ). 
     
     
         11 . The non-contact handling tool according to any of the preceding claims characterised in that the ultrasonic transducer comprises a head ( 28 ) interchangeably coupled to a front body of the transmission device, the picking side being arranged on the head. 
     
     
         12 . The non-contact handling tool according to the preceding claim comprising a set of several interchangeable heads of different forms or dimensions. 
     
     
         13 . The non-contact handling tool according to any of the two preceding claims characterised in that the head ( 28 ) and front body comprises additional securing members in the form of a bayonet securing system. 
     
     
         14 . The non-contact handling tool according to any of the preceding claims characterised in that the picking side is flat. 
     
     
         15 . The non-contact handling tool according to any of the preceding claims characterised in that the picking side has a curved form, configured to be compliant with a portion of the surface of the object to be picked up. 
     
     
         16 . The non-contact handling tool according to any of the preceding claims characterised in that the picking side comprises a hydrophobic or lipophobic surface. 
     
     
         17 . The non-contact handling tool according to the preceding claim characterised in that the picking side has a concave form. 
     
     
         18 . The non-contact handling tool according to any of the preceding claims further comprising an electric discharge device ( 40 ) for neutralising an electric charge of the object. 
     
     
         19 . The non-contact handling tool according to any of the preceding claims, characterised in that the picking side surface is within a range of 0.01 to 650=2. 
     
     
         20 . The non-contact handling tool according to any of the preceding claims, characterised in that the front body comprises at least two successive diameter reductions D 1 , D 1 , D 3  in the direction of the ultrasonic generator ( 12 ) towards the picking side ( 29 ), the ratios between the successive diameters D 1 , D 1  and D 3  in said direction is found in one range:
 for D 1 /D 2 , between max 2.6 and min 1.1 
 for D 2 /D 3 , between max 6 and min 1.1 
 
       and for any additional reduction between max 6 and min 1.1. 
     
     
         21 . The non-contact handling tool according to any of the preceding claims in conjunction with an object to be picked up, characterised in that the picking side of the tool has an identical surface size, or within a range of 90% to 110% of the surface size of the object to be picked up. 
     
     
         22 . A non-contact handling system comprising a non-contact handling tool according to any of the preceding claims, a control unit ( 4 ) connected to an ultrasonic generator of the ultrasonic transducer and, a suction device ( 6 ) comprising a suction pump connected to the fluid suction channel, the control unit and the ultrasonic transducer being configured to generate ultrasounds at a frequency within a 20 kHz to 150 kHz range. 
     
     
         23 . The handling system according to the preceding claim, characterised in that the control unit and the ultrasonic transducer are configured to generate ultrasounds at a frequency within a 40 kHz to 140 kHz range. 
     
     
         24 . The non-contact handling system according to any of the preceding claims, characterised in that the control unit comprises a control circuit connected to the ultrasonic generator and to the suction pump for simultaneously controlling the suction power and the generation of ultrasounds. 
     
     
         25 . A method for the non-contact handling of an object, including:
 providing a handling system according to any of the preceding claims,   activating the suction pump to create a suction force and the ultrasonic generator to create a repulsive force, with respect to the picking side,   placing the picking side of the handling tool facing a surface of the object at a distance within a range of 0.5 to 6 times the suspension distance d s ,   suspending the object at a non-null suspension distance with respect to the picking side by simultaneously monitoring the suction pump and the ultrasonic generator, the suspension distance being monitored to be in a near field area of the ultrasounds.   
     
     
         26 . The handling method according to the preceding claim, characterised in that the ultrasonic transducer is configured and monitored to generate ultrasounds at a frequency within a 20 kHz to 150 kHz range, preferably within a 40 kHz to 140 kHz range. 
     
     
         27 . The handling method according to any of the two preceding claims, characterised in that said suspension distance ranges between 1 and 80 micrometers, preferably between 1 and 60 micrometers, particularly between 5 and 50 micrometers. 
     
     
         28 . The handling method according to any of the three preceding claims, characterised in that the transducer is operated at a forced anti-resonant frequency. 
     
     
         29 . A handling tool for the non-contact handling of an object ( 3 ), the tool comprising an ultrasonic transducer ( 10 ) and at least a suction channel ( 30 ), the ultrasonic transducer including:
 a body ( 24   a ,  24   b ,  24   c ) and a head ( 28 ), said head being at one end of said body and comprising a picking side ( 11 ) intended to be positioned facing the object to be handled, the body comprising a reflective side ( 21 ) for ultrasounds positioned at the end of the body opposite the head, the head and the body being able to be separated, and   an ultrasonic generator arranged to generate near field ultrasounds that exert a repulsive force to move the object away from the head;   said at least one suction channel ( 30 ) traverses the body and the head, said suction channel being arranged to guide the suction which exerts an attractive force to bring the object near to the head in the direction opposite to that of the repulsive force,   such that in the simultaneous presence of near field ultrasounds and suction, the object is maintained at a non-null suspension distance (d s ) from the picking side.   
     
     
         30 . The non-contact handling tool according to the preceding claim comprising a set of several interchangeable heads of different dimensions. 
     
     
         31 . A handling tool for the non-contact handling of an object ( 3 ), the tool comprising an ultrasonic transducer ( 10 ) and at least a suction channel ( 30 ), the ultrasonic transducer including:
 a body ( 24   a ,  24   b ,  24   c ) and a head ( 28 ), said head being at one end of said body and comprising a picking side ( 11 ) intended to be positioned facing the object to be handled, the body comprising a reflective side ( 21 ) for ultrasounds positioned at the end of the body opposite the head, and   an ultrasonic generator arranged to generate near field ultrasounds that exert a repulsive force to move the object away from the head;   said at least one suction channel ( 30 ) crosses the body and the head, said suction channel being arranged to guide the suction which exerts an attractive force to bring the object near to the head in the direction opposite to that of the repulsive force,   such that in the simultaneous presence of near field ultrasounds and suction, the object is maintained at a non-null suspension distance from the picking side.   the ultrasonic generator comprising at least one pair of superimposed piezoelectric members ( 14 ), preferably piezoceramic, said pair being screwed in the body with a bolt, the suction channel extending through the bolt.   
     
     
         32 . The tool according to  claim 29  or  31 , further comprising the characteristics of any one of  claims 1  to  21 .