Apparatus for surface finishing workpieces and chucking device of an apparatus of this kind

Abstract

An apparatus for surface finishing workpieces has a workpiece holder, on which a chucking device for releasably fixing the workpieces to be machined is secured, and a container arranged underneath the workpiece holder in order to receive grinding and/or polishing granules, which can be moved relative to the workpiece holder. A chucking device has a chuck, which is designed for at least partially positive holding of the workpiece for conjoint rotation. The chucking device furthermore has a vacuum duct, which can be connected to a vacuum generator and which opens into the chuck in order to hold the workpiece in such a way that it is fixed axially by the application of a vacuum to the vacuum duct. The chuck of the chucking device is arranged on an adapter piece, which can be fixed releasably on a supporting part of the chucking device.

1 - 20 . (canceled) 
     
     
         21 . An apparatus for surface finishing workpieces by moving the workpieces relative to grinding and/or polishing granules or for drag finishing and/or plunge finishing the workpieces, the apparatus comprising:
 at least one workpiece holder;   a container disposed below said workpiece holder, said container structured to receive the grinding and/or polishing granules for movement of the grinding and/or polishing granules relative to said workpiece holder; and   at least one chucking device cooperating with said workpiece holder for releasably fixing the workpieces to be machined, said chucking device having a chuck, an adaptor piece and a supporting part connected to said workpiece holder, wherein said chuck is structured for at least partial positive holding of the workpiece for conjoint rotation, said chucking device defining at least one vacuum duct structured for connection to a vacuum generator, said duct having an opening into said chuck to hold the workpiece and to axially fix the workpiece by application of a vacuum to said vacuum duct, wherein said chuck is mounted on said adapter piece and said adaptor piece is fixed to said supporting part in a releasable manner.   
     
     
         22 . The apparatus of  claim 21 , wherein said chuck has at least one structure selected from the group comprising:
 an axially protruding circumferential rim having a first noncircular internal cross section in order to fit at least partially and in a positive manner around a first noncircular external cross section of the workpiece, the external cross section being complementary to said first internal cross section, at least in a certain segment or segments;   at least one first axially protruding projection having a second noncircular external cross section in order to engage at least partially in a positive manner in a noncircular hole in the workpiece, the hole being complementary to said second external cross section, at least in a certain segment or segments;   at least two adjacent, axially protruding pins for engaging at least partially in a positive manner in at least two holes in the workpiece, which are arranged at a spacing corresponding to a spacing of said pins;   at least one first axially set-back depression having a second noncircular internal cross section for receiving at least partially and in a positive manner a noncircular second projection on the workpiece, the second projection being complementary to said second internal cross section, at least in a certain segment or segments; and   at least two adjacent, second axially set-back depressions for receiving at least partially and in a positive manner at least two third projections on the workpiece, which are arranged at a spacing corresponding to a spacing of said second depressions.   
     
     
         23 . The apparatus according of  claim 21 , wherein said chuck has at least one seal, which surrounds said vacuum duct opening into said chuck and/or said chuck is coated with a flexible sealing material on an end thereof surrounding a mouth of said vacuum duct, said chuck thereby sealing off said vacuum duct with respect to the workpiece when the workpiece is inserted into said chuck. 
     
     
         24 . The apparatus of  claim 23 , wherein said seal is inserted into an annular groove in said chuck. 
     
     
         25 . The apparatus of  claim 21 , wherein said adapter piece is penetrated by said vacuum duct and is fixed on said supporting part in such a way that said vacuum duct penetrates through said adapter piece and is connected to a suction duct in said supporting part, said suction duct being structured for connection to a vacuum generator. 
     
     
         26 . The apparatus of  claim 21 , wherein said adapter piece is fixed to said supporting part in a releasable manner using screws, bolts, clips or toggle-type fasteners. 
     
     
         27 . The apparatus of  claim 25 , wherein said supporting part has a holding structure, which is designed for holding said adapter piece for conjoint rotation and which is of complementary design to a holding structure of said adapter piece, said adapter piece being held in an axially fixed manner on said supporting part by applying a vacuum to said suction duct in said supporting part and suctioning said adapter piece against said supporting part when said vacuum duct in said adapter piece has been closed by insertion of the workpiece into said chuck. 
     
     
         28 . The apparatus of  claim 27 , wherein mutually complementary holding structures of said supporting part and said adapter piece have:
 at least one third noncircular external cross section of said supporting part or of said adapter piece and a third noncircular internal cross section of said adapter piece or of said supporting part, said third internal cross section being complementary to said third external cross section and fitting around said third external cross section at least partially in a positive manner;   at least one third depression having a fourth noncircular internal cross section in said supporting part or in said adapter piece and a third projection on said adapter piece or on said supporting part, said third projection being complementary to said fourth internal cross section and engaging at least partially in a positive manner in said third depression; and/or   at least two adjacent fourth depressions in said supporting part or in said adapter piece and at least two adjacent fourth projections on said adapter piece or on said supporting part, which are complementary to said fourth depressions, are arranged at a spacing corresponding to said fourth depressions and engage in said fourth depressions.   
     
     
         29 . The apparatus of  claim 25 , wherein, on an end facing said adapter piece and/or facing said supporting part, said supporting part and/or said adapter piece:
 has at least one seal, which surrounds said suction duct in said supporting part, said duct opening into said vacuum duct in said adapter piece; and/or   is coated with a flexible sealing material, in order to seal off said suction duct in said supporting part with respect to said vacuum duct in said adapter piece.   
     
     
         30 . The apparatus of  claim 21 , wherein said chucking device is structured for attachment to said workpiece holder in a releasable manner using a quick release fastener arranged on said supporting part or said supporting part is integral with said workpiece holder. 
     
     
         31 . The apparatus of  claim 25 , wherein said vacuum duct and/or said suction duct is fitted with at least one shutoff valve in order to supply said chuck with a vacuum or with ambient pressure. 
     
     
         32 . The apparatus of  claim 21 , further comprising a vacuum line connecting said chucking device to a vacuum generator, said vacuum line having at least one shutoff valve to supply said chuck with a vacuum or with ambient pressure. 
     
     
         33 . The apparatus of  claim 21 , further comprising at least one lifting device to which said workpiece holder is mounted and a movable part to which said lifting device is mounted, said movable part structured for moving said workpiece holder back and forth between an upper position and a lower position, wherein said upper position is disposed above said container and is a position at which machined workpieces can be removed from said chucking device and at which said chucking device can be loaded with unprocessed workpieces, wherein said lower position is a position at which the workpieces releasably secured on said chucking device dip into said container for machining. 
     
     
         34 . The apparatus of  claim 33 , wherein said movable part is structured to transfer a plurality of workpiece holders successively into one single loading/removal position. 
     
     
         35 . The apparatus of  claim 34 , wherein said movable part is structured for rotation. 
     
     
         36 . The apparatus of  claim 35 , wherein said lifting devices are disposed on said movable part eccentrically with respect to an axis of rotation thereof and one behind an other in a circumferential direction, said movable part being rotated backward and forward at least through an angle sufficient to successively transfer each workpiece holder to said loading/removal position. 
     
     
         37 . The apparatus of  claim 35 , wherein an axis of rotation of said movable part is in alignment with a rotational axis of said container. 
     
     
         38 . The apparatus of  claim 21 , wherein said workpiece holder is rotatable or is rotatable under control. 
     
     
         39 . A chucking device for releasably fixing workpieces to be machined in an apparatus for surface finishing workpieces by moving the workpieces relative to grinding and/or polishing granules disposed in a bed thereof or for drag finishing and/or plunge finishing the workpieces, the apparatus having at least one workpiece holder for releasably securing the chucking device and a container arranged beneath the workpiece holder to receive the grinding and/or polishing granules, the chucking device comprising:
 a supporting part;   an adaptor piece releasably mounted to said supporting part; and   a chuck mounted to said adaptor piece, said chuck structured for at least partial positive holding of the workpiece for conjoint rotation, wherein the chucking device defines at least one vacuum duct structured for connection to a vacuum generator, said vacuum duct opening into said chuck to hold the workpiece and to fix the workpiece axially by application of a vacuum to said vacuum duct.   
     
     
         40 . The chucking device of  claim 39  wherein said chuck has at least one structure selected from the group comprising:
 an axially protruding circumferential rim having a first noncircular internal cross section in order to fit at least partially and in a positive manner around a first noncircular external cross section of the workpiece, the external cross section being complementary to said first internal cross section, at least in a certain segment or segments; 
 at least one first axially protruding projection having a second noncircular external cross section in order to engage at least partially in a positive manner in a noncircular hole in the workpiece, the hole being complementary to said second external cross section, at least in a certain segment or segments; 
 at least two adjacent, axially protruding pins for engaging at least partially in a positive manner in at least two holes in the workpiece, which are arranged at a spacing corresponding to a spacing of said pins; 
 at least one first axially set-back depression having a second noncircular internal cross section for receiving at least partially and in a positive manner a noncircular second projection on the workpiece, the second projection being complementary to said second internal cross section, at least in a certain segment or segments; and 
 at least two adjacent, second axially set-back depressions for receiving at least partially and in a positive manner at least two third projections on the workpiece, which are arranged at a spacing corresponding to a spacing of said second depressions.