Simultaneous grinding machine

Abstract

An apparatus for grinding an elongated workpiece having a plurality of outer surfaces of revolution all centered on a common workpiece axis has a frame and a chuck on the frame for orienting the workpiece with the workpiece axis vertical and for rotating the workpiece about the workpiece axis. Two grinder drive motors on the frame diametrally flank the workpiece axis, are displaceable horizontally and radially of the workpiece axis, and each have a downwardly extending respective vertical drive shaft rotatable about a respective shaft axis, carrying a respective set of at least two vertically and axially spaced grinding wheels, and each having an unsupported and unbraced lower end. The grinders are displaced in respective diametrally opposite horizontal and radial directions for engaging the grinding wheels with the surfaces of the rotating workpiece grinder, such that all the surfaces of the workpiece can be ground simultaneously.

I claim: 
     
         1 . An apparatus for grinding an elongated workpiece having a plurality of outer surfaces of revolution all centered on a common workpiece axis, the apparatus comprising:
 a frame;   means on the frame for orienting the workpiece with the workpiece axis vertical and for rotating the workpiece about the workpiece axis;   two grinder motors on the frame diametrally flanking the workpiece axis and displaceable horizontally and radially of the workpiece axis and each having a downwardly extending respective vertical drive shaft rotatable about a respective shaft axis, carrying a respective set of at least two vertically and axially spaced grinding wheels, and each having an unsupported and unbraced lower end; and   means for displacing the grinders in respective diametrally opposite horizontal and radial directions for engaging the grinding wheels with the surfaces of the rotating workpiece grinder, axial spacing and dimensions of the wheels corresponding to axial spacing and dimensions of the surfaces such that all the surfaces of the workpiece can be ground simultaneously.   
     
     
         2 . The grinding apparatus defined in  claim 1 , wherein for each surface of revolution there is at least one respective grinding wheel. 
     
     
         3 . The grinding apparatus defined in  claim 2 , wherein at least one of the grinding wheels of one of the sets is axially and vertically level with one of the grinding wheels of the other set so that the respective surface is engaged by two grinding wheels. 
     
     
         4 . The grinding apparatus defined in  claim 2 , wherein two of the grinding wheels of one of the sets are axially level and vertically with two of the grinding wheels of the other set so that two of the surfaces are engaged by two grinding wheels. 
     
     
         5 . The grinding apparatus defined in  claim 2 , wherein each of the grinding wheels of one of the sets is axially level with a respective one of the grinding wheels of the other set so that each of the workpiece surfaces is engaged by two grinding wheels. 
     
     
         6 . The grinding apparatus defined in  claim 2 , wherein at least one of the grinding wheels of each of the sets is axially between two of the grinding wheels of the other of the sets. 
     
     
         7 . The grinding apparatus defined in  claim 1 , wherein the workpiece is a crankshaft and the surfaces include journals between adjacent crankpins and bearing surfaces at ends of the crankshaft, each of the wheels also being engageable with axially directed faces of flanges carrying the crankpins and flanking the journals. 
     
     
         8 . The grinding apparatus defined in  claim 1 , further comprising:
 a steady rest engageable with the workpiece in a direction perpendicular to a plane defined by the workpiece axis and shaft axes about which the wheels are rotated.   
     
     
         9 . An apparatus for grinding an elongated workpiece having a plurality of outer surfaces of revolution all centered on a common workpiece axis, the apparatus comprising:
 a frame;   means on the frame for orienting the workpiece with the workpiece axis vertical and for rotating the workpiece about the workpiece axis;   two grinder drives on the frame diametrally flanking the workpiece axis and displaceable radially of the workpiece axis and each having a respective vertically depending shaft carrying a respective set of at least two axially spaced grinding wheels, a lower end of each shaft being unsupported and unbraced;   means for displacing the grinders in respective diametrally opposite horizontal directions for horizontally engaging the grinding wheels with the surfaces of the rotating workpiece grinder, axial spacing and dimensions of the wheels corresponding to axial spacing and dimensions of the surfaces such that all the surfaces of the workpiece can be ground simultaneously; and   a steady rest engageable horizontally with the workpiece in a direction perpendicular to a plane defined by the workpiece axis and axes about which the wheels are rotated and opposite a direction in which rotation of the wheel urges the workpieces.   
     
     
         10 . The grinding apparatus defined in  claim 9 , wherein the sets are rotated about respective axes diametrally flanking the workpiece axis in such a direction as to exert tangential forces on the workpiece urging the workpiece against the steady rest.