Apparatus for holding and transporting a workpiece having a plane surface

Abstract

Apparatus for holding and transporting a workpiece having a plane surface The apparatus allows the lifting, holding and transporting of a workpiece comprising an opening or impression, by using the Venturi effect of a gas stream between said apparatus and the workpiece.

1 . A method for lifting a workpiece ( 2 ) comprising a substantially plane surface ( 4 ) on a lifting side, the method comprising the following steps: 
 (a) providing a lifting apparatus ( 1 ) having a gas supply ( 8 ) and a plane parallel holding surface ( 7 ) which is facing the surface ( 4 ) of the workpiece ( 2 ),    (b) moving and positioning the lifting apparatus ( 1 ) in a direction parallel to the surface ( 4 ) of the workpiece ( 2 ) in a predetermined distance to the workpiece ( 2 ),    (c) inserting a gas or a gas mixture over a gas supply ( 8 ) into a space ( 9 ) between the plane parallel holding surface ( 7 ) and the workpiece ( 2 ) and generating a gas stream through a gap ( 10 ) formed between the surface ( 4 ) of the workpiece ( 2 ) and the plane parallel holding surface ( 7 ) and generating a low pressure between the surface ( 4 ) of the workpiece ( 2 ) and the lifting apparatus ( 1 ) and, thus, a lifting force exerting onto the workpiece for lifting the workpiece ( 2 ) along a predetermined lifting distance.    
   
   
       2 . The method according to  claim 1 , wherein the gas or gas mixture is inserted into the gas supply ( 8 ) at a pressure of about 1 bar to about 7 bar.  
   
   
       3 . The method according to  claim 1 , wherein the lifting distance is about 50 mm.  
   
   
       4 . The method according to  claim 1 , wherein the inserted gas cools down the workpiece ( 2 ).  
   
   
       5 . The method according to  claim 1 , wherein the workpiece ( 2 ) is deposited by interrupting the gas supply.  
   
   
       6 . The method according to  claim 1 , 
 wherein the workpiece comprises a through-going opening ( 3 ) or an impression on the lifting surface and the lifting apparatus comprises a holding plug ( 6 ) for engaging into the opening ( 3 ) or impression in order to position the workpiece ( 2 ).    
   
   
       7 . A lifting apparatus for performing the method according to  claim 1 .  
   
   
       8 . Method for lifting, holding and/or transporting and depositing a workpiece ( 2 ), wherein the lifting movement of the workpiece ( 2 ) is performed according to the method of  claim 1  when the workpiece is lifted and/or deposited.  
   
   
       9 . Apparatus ( 1 ) for lifting, holding and/or transporting a workpiece ( 2 ), which comprises a plane surface ( 4 ) on the holding surface and an impression or through-going opening ( 3 ) on said surface ( 4 ), comprising: 
 (a) a holding plug ( 6 ) which can engage with an impression or the opening ( 3 ) in the surface ( 4 ) of the workpiece ( 2 ),    (b) a holding surface ( 7 ) surrounding the holding plug ( 6 ), facing the plane surface of the holding side of the workpiece ( 2 ) and being plane parallel to said surface, and    (c) a gas supply ( 8 ) for inserting gas or a gas mixture into a space ( 9 ) located in the area of the holding plug ( 6 ), between the holding plug ( 6 ), the plane surface ( 4 ) of the workpiece ( 2 ) and the plane parallel area section ( 7 ) and for generating a gas stream through a gap ( 10 ) formed between the surface ( 4 ) of the workpiece ( 2 ) and the plane parallel area section ( 7 ).    
   
   
       10 . The apparatus according to  claim 9 , wherein the holding plug ( 6 ) and the plane parallel holding surface ( 7 ) are configured axially symmetrical and are arranged coaxially with respect to each other.  
   
   
       11 . The apparatus according to  claim 9 , wherein the diameter of the holding plug ( 6 ) is adjusted to the central opening of a CD, DVD or a Blu-ray disk.  
   
   
       12 . The apparatus according to  claim 9 , wherein the holding plug ( 6 ) comprises a predetermined length, so that the holding plug ( 6 ) extends over the opening ( 3 ) of a workpiece ( 2 ) or into the impression of a workpiece ( 2 ), and that the workpiece ( 2 ) cannot drop unintentionally from the holding plug ( 6 ) when hold or transported by the apparatus ( 1 ).  
   
   
       13 . The apparatus according to  claim 9 , wherein the holding plug ( 6 ) can be fixed detachably at the apparatus ( 1 ).  
   
   
       14 . The apparatus according to  claim 9 , wherein the holding plug ( 6 ) preferably comprises a beveled edge ( 11 ).  
   
   
       15 . The apparatus according to  claim 9 , wherein the holding plug ( 6 ) comprises at least one recess or at least one projection for centering in a correspondingly adapted complementary counterpart when the workpiece ( 2 ) is lifted or deposited.  
   
   
       16 . The apparatus according to  claim 9 , wherein the holding plug ( 6 ) or an ejecting means ( 61 ) is configured such that it is displaceable in a direction vertical to the holding surface ( 7 ) with respect to the apparatus ( 1 ).  
   
   
       17 . The apparatus according to  claim 16 , wherein the holding plug ( 6 ) or the ejecting means ( 61 ) can be biased towards the apparatus ( 1 ) by a spring arrangement.  
   
   
       18 . The apparatus according to any one of claims  16 , wherein the holding plug ( 6 ) or the ejecting means ( 61 ) is arranged at a coaxial piston ( 32 ) which can be moved axially with the holding plug ( 6 ) when the supply of the gas or the gas mixture is interrupted or reduced, so that the holding plug ( 6 ) or the ejecting means ( 61 ) can be moved away from the holding surface ( 7 ).  
   
   
       19 . The apparatus according to  claim 9 , wherein a play ( 5 ) is provided between the holding plug ( 6 ) and the impression or the through-going opening ( 3 ) of the workpiece ( 2 ), the play being adjusted in such a manner, that the workpiece ( 2 ) can be picked up and deposited again by the holding plug ( 6 ) without any disturbing friction forces.  
   
   
       20 . The apparatus according to  claim 9 , herein the cross-section of the space ( 9 ) diminishes from the inner side towards the outer side.  
   
   
       21 . The apparatus according to  claim 20 , wherein the space ( 9 ) comprises a conical shape.  
   
   
       22 . The apparatus according to  claim 9 , wherein the space ( 9 ) is configured as ringspace.  
   
   
       23 . The apparatus according to  claim 9 , wherein the gap ( 10 ) between the holding surface ( 7 ) and the workpiece ( 2 ) is configured as ringgap.  
   
   
       24 . The apparatus according to  claim 9 , wherein the gas or the gas mixture is inserted into the apparatus at a predetermined pressure, which is chosen such that a low pressure is generated in the gap ( 10 ) and, thus, a sufficient lifting force for holding the workpiece ( 2 ) is exerted onto the workpiece ( 2 ).  
   
   
       25 . The apparatus according to  claim 24 , wherein the apparatus comprises at least one distance piece at the plane parallel holding surface ( 7 ), the distance piece limiting the gap ( 10 ).  
   
   
       26 . The apparatus according to  claim 9 , wherein the holding plug ( 6 ) comprises a stop ( 6 ′) by which a predetermined distance (d) between the holding surface ( 7 ) and the surface ( 4 ) of the workpiece ( 2 ) is guaranteed.  
   
   
       27 . The apparatus according to  claim 9 , wherein the gas or gas mixture is inserted into the apparatus at a predetermined pressure, which is chosen such that a low pressure is generated between the apparatus and the surface ( 4 ) of the workpiece ( 2 ) and, thus, a lifting force for lifting the workpiece ( 2 ) over a predetermined lifting distance is exerted onto the workpiece ( 2 ).  
   
   
       28 . The apparatus according to  claim 9 , wherein the gas or gas mixture is inserted over the gas supply ( 8 ) at a pressure of about 1 bar to 7 bar.  
   
   
       29 . The apparatus according to  claim 27 , wherein the lifting distance is about 50 mm.  
   
   
       30 . The apparatus according to  claim 9 , wherein the apparatus ( 1 ) is essentially axially symmetrical.  
   
   
       31 . The apparatus according to  claim 9 , having a means ( 81 ) for guiding the gas or the gas mixture in the direction of the surface of the workpiece ( 2 ) facing away from the apparatus ( 1 ), preferably at an acute angle.  
   
   
       32 . The apparatus according to  claim 9 , wherein the holding surface ( 7 ) radially extends at least partially over the outer circumference of the workpiece ( 2 ) and is configured beveled, preferably conical towards the workpiece at the side facing the circumference of the workpiece ( 2 ).  
   
   
       33 . Method for lifting, holding and/or transporting a workpiece ( 2 ) comprising a plane surface ( 4 ) at the holding side and an impression or a through-going opening ( 3 ) on said surface ( 4 ), the method using the apparatus according to any one of  claims 9  to  32 , comprising the following steps: 
 (a) moving the apparatus ( 1 ) with the holding plug ( 6 ) at a predetermined distance to the workpiece ( 2 ) into a position coaxially above the impression or through-going opening ( 3 ) of the workpiece ( 2 ),    (b) inserting a gas or a gas mixture in the gas supply ( 8 ) into the apparatus at a predetermined pressure and generating a gas stream through the gap ( 10 ) formed between the surface ( 4 ) of the workpiece ( 2 ) and the plane parallel holding surface ( 7 ) of the apparatus for exerting a lifting force onto the workpiece ( 2 ), and    (c) generating a low pressure in the gap ( 10 ) for exerting a lifting force onto the workpiece ( 2 ).    
   
   
       34 . The method according to  claim 33 , wherein the apparatus is moved and positioned parallel to the surface ( 4 ) of the workpiece and the holding plug is positioned vertically above the impression or opening ( 3 ) of the workpiece ( 2 ).  
   
   
       35 . The method according to  claim 33 , comprising the step: 
 inserting the gas or the gas mixture into the apparatus at a pressure which is selected such that a low pressure is generated between the apparatus and the surface ( 4 ) of the workpiece ( 2 ) which effects a lifting force for lifting the workpiece ( 2 ) along a predetermined lifting path.    
   
   
       36 . The method according to  claim 33 , comprising the step: inserting the gas or the gas mixture into the gas supply ( 8 ) at a pressure of about 1 bar to 7 bar.  
   
   
       37 . The method according to  claim 35 , wherein the lifting path has a distance of about 50 mm.  
   
   
       38 . The method according to  claim 33 , wherein the apparatus is first moved and positioned in a direction parallel and vertically to the surface ( 4 ) of the workpiece and wherein the gap ( 10 ) is preferably limited by at least one distance piece arranged at the apparatus when the apparatus is moved vertically in the direction towards the surface ( 4 ) of the workpiece ( 2 ).  
   
   
       39 . The method according to  claim 38 , wherein the gas or the gas mixture is inserted into the apparatus at a predetermined pressure which is selected such that a low pressure is generated in the gap ( 10 ), the low pressure effecting a force for holding the workpiece ( 2 ).  
   
   
       40 . The method according to  claim 33 , comprising the step: depositing or releasing the workpiece ( 2 ) by interrupting the gas supply.