Precision assembly table and method

Abstract

A precision assembly table and method includes a plurality of rigid bars connected to adjustable support members which can individually adjust the position of the rigid bars above a surface and a frame to create a desired contour. The structure to be assembled, such as a magnetic levitation guideway, is positioned and held in place on top of the rigid bars which have been positioned so as to define a desired contour of the structure and to which the structure will mechanically conform. The position of the rigid bars is monitored and adjusted by a computer to maintain the desired contour while the structure resting on the rigid bars is being assembled.

What is claimed is:  
     
         1 . A precision assembly apparatus comprising: 
 a frame;    a plurality of rigid bars upon which items to be assembled are positioned; and    means for connecting said rigid bars to said frame and adjusting the position of said bars relative to said frame such that the plurality of said bars defines a desired contour that said items to be assembled will be positioned upon and to which said items to be assembled will mechanically adjust.    
     
     
         2 . A precision assembly apparatus comprising: 
 a frame;    a plurality of rigid bars upon which items to be assembled are positioned;    a plurality of adjustable support members wherein each of said rigid bars is connected to at least two of said adjustable support members and wherein said adjustable support members are connected to said frame such that the position of each of said rigid bars above said frame is capable of individual adjustment and the contour defined by such rigid bars is adjustable by adjustment of said adjustable support members; and    a hold down fixture capable of holding said items to be assembled in position.    
     
     
         3 . The precision assembly apparatus in    claim 2    wherein each of said adjustable support members is a screw.  
     
     
         4 . A precision assembly table comprising: 
 a frame;    a surface connected to the top of said frame;    a plurality of rigid bars above said surface that define a contoured surface upon which items to be assembled are positioned;    a plurality of adjustable support members wherein each of said rigid bars is connected to at least two of said adjustable support members and wherein said adjustable support members are connected to said frame such that the position of each of said rigid bars above said frame and said surface is capable of individual adjustment and the countered surface defined by said rigid bars is capable of adjustment by adjustment of said adjustable support members; and    a hold down fixture capable of holding said items to be assembled in position.    
     
     
         5 . The precision assembly table in    claim 4    wherein each of said adjustable support members comprises a screw.  
     
     
         6 . The precision assembly table in    claim 4    wherein each of said adjustable support members comprises a screw connected to said rigid bar with a ball and socket and wherein said screw is adjusted by operation of an electric servo motor upon a worm gear connected to said screw.  
     
     
         7 . The precision assembly table in    claim 4    further comprising: 
 position sensors connected to the ends of said rigid bars capable of monitoring the position of said rigid bars.  
 
     
     
         8 . The precision assembly table in    claim 4    further comprising: 
 reflectors connected to the ends of said rigid bars capable of measuring the position of said rigid bars by application of a laser scan on said reflectors.  
 
     
     
         9 . The precision assembly table of    claim 4    wherein said rigid bars are positioned parallel to each other.  
     
     
         10 . The precision assembly table of    claim 4    wherein the adjustment of the adjustable support members and position of said rigid bars is computer controlled.  
     
     
         11 . A precision magnetic levitation vehicle guideway assembly table comprising: 
 a frame;    a surface connected to the top of said frame;    a plurality of rigid bars above said surface that define a contoured surface upon which the guide plate of a magnetic levitation vehicle guideway to be assembled is positioned;    a plurality of adjustable support members wherein each of said support bars is connected to at least two of said adjustable support members and wherein said adjustable support members are connected to said frame such that the position of each of said rigid bars above said frame and said surface is capable of individual adjustment and the countered surface defined by said rigid bars and to which said guide plate will mechanically conform is capable of adjustment by adjustment of said adjustable support members; and    a hold down fixture capable of holding said guide plate in position.    
     
     
         12 . The precision assembly table in    claim 11    wherein each of said adjustable support members comprises a screw.  
     
     
         13 . The precision assembly table in    claim 11    wherein each of said adjustable support members comprises a screw connected to said rigid bar with a ball and socket and wherein said screw is adjusted by operation of an electric servo motor upon a worm gear connected to said screw.  
     
     
         14 . The precision assembly table in    claim 11    further comprising: 
 position sensors connected to the ends of said rigid bars capable of monitoring the position of said rigid bars.  
 
     
     
         15 . The precision assembly table in    claim 11    further comprising: 
 reflectors connected to the ends of said rigid bars capable of measuring the position of said rigid bars by application of a laser scan on said reflectors.  
 
     
     
         16 . The precision assembly table of    claim 11    wherein said rigid bars are positioned parallel to each other.  
     
     
         17 . The precision assembly table of    claim 11    wherein the adjustment of the adjustable support members and position of said rigid bars is computer controlled.  
     
     
         18 . A method of assembling a contoured structure comprising: 
 individually adjusting a plurality of rigid bars to the desired contoured surface of a portion of said contoured structure on a precision assembly table comprising said plurality of rigid bars whose position is capable of individual adjustment and that define a contoured surface;    positioning said portion of said contoured structure on said plurality of rigid bars;    holding said portion of said contoured structure in position on said plurality of rigid bars disposed to form the desired contour with a hold down fixture;    allowing said portion of said contoured structure to mechanically conform to said contoured surface established by said plurality of rigid bars; and    connecting the remaining portions of said contoured structure to said portion of said contoured structure positioned on said precision assembly table after said portion of said contoured structure has conformed to said contoured surface to form said contoured structure;    measuring the position of said rigid bars during assembly operations; and    adjusting the position of said rigid bars so that their position conforms to the desired contour.    
     
     
         19 . A method of assembling a guideway for a magnetic levitation vehicle comprising: 
 individually adjusting a plurality of rigid bars to the desired contoured surface of a guide plate for said guideway on a precision assembly table comprising a plurality of rigid bars whose position is individually adjustable and that define a contoured surface;    positioning of said guide plate of said guideway on said plurality of rigid bars;    holding said guide plate of said guideway in position on said plurality of rigid bars disposed to form the desired contour with a hold down fixture;    allowing the surface of said guide plate to mechanically conform to said contoured surface established by said plurality of rigid bars;    welding stiffeners and support plates to said guide plate after it has conformed to said contoured surface to form a guideway;    measuring the position of said rigid bars during assembly operations; and    adjusting the position of said rigid bars so that their position conforms to the desired contour.