Method and apparatus for machining holes in crankshafts

Abstract

A crankshaft is mounted in a fixture which rotates the crankshaft about its longitudinal axis and which tilts the cranksahft about a horizontal axis to allow matching of holes such as oil holes at various rotational positions and at various tilt angles to the longitudinal axis. Preferably, a cutting tool moves along a horizontal plunging axis Z to machine the depth of the hole and moves along a horizontal X axis to machine holes on or offset from the longitudinal axis. The cutting tool may also be shifted vertically along a Y-axis. Preferably, a pair of crankshafts are mounted side-by-side in the fixture to machine two crankshafts simultaneously. The fixture is mounted for tilting by trunnions. The pair of crankshafts are spun about the longitudinal axes by a motor carried on the tiltable fixture. An automatic tool changer and loading apparatus store cutting tools and associated guide bushings for the cutting tools.

What is claimed is:  
     
       1. An apparatus for machining holes in crankshafts at various angular positions about a longitudinal axis through the crankshaft and at various tilt angles to the rotational axis, comprising: 
       a frame;  
       a rotational means on the frame for supporting a crankshaft and for rotating the crankshaft about the crankshaft's longitudinal axis to present different angular positions for the machining of holes;  
       a machine head mounted on the frame with a tool, movable along a plunging axis to present the tool to the crankshaft to machine holes therein; and  
       tilt means on the frame mounting the crankshaft to tilt the crankshaft at various angles to the plunging axis so that holes may be machined at various rotational positions about the crankshaft and at various tilt angles to its longitudinal axis.  
     
     
       2. An apparatus in accordance with  claim 1  wherein rotational means comprises a crankshaft supporting fixture, means in the fixture mounting the crankshaft for turning about the rotational axis of the crankshaft within the fixture; and wherein the tilt means includes pivot means on the frame for pivotally mounting the fixture to pivot relative to the plunging axis. 
     
     
       3. The apparatus of  claim 2  wherein a slide means of the machine frame guides the machine head for travel along the plunging axis, another slide means of the machine frame guides the machine head for travel along a first positioning axis normal to the plunging axis, and another slide means of the machine frame guides the machine head for travel along a second positioning axis that is normal to both the first positioning axis and the plunging axis. 
     
     
       4. The apparatus of  claim 1  further comprising means for storing a plurality of tools and tool support bushings, adjacent the machine head for automatic transfer of different tools to the machine head. 
     
     
       5. The apparatus of  claim 1  further comprising means for positioning a tool support bushing in correct position between the crankshaft and the tool. 
     
     
       6. An apparatus of  claim 1  wherein  An apparatus for machining holes in crankshafts at various angular positions about a longitudinal axis through the crankshaft and at various tilt angles to the rotational axis comprising: 
       
         a frame:  
       
       
         a rotational means on the frame for supporting a crankshaft and for rotating the crankshaft about the crankshaft's longitudinal axis to present different angular positions for the machining of holes;  
       
       
         a machine head mounted on the frame with a tool, movable along a plunging axis to present the tool to the crankshaft to machine holes therein;  
       
       
         tilt means on the frame mounting the crankshaft to tilt the crankshaft at various angles to the plunging axis so that holes may be machined at various rotational positions about the crankshaft and at various tilt angles to its longitudinal axis; 
       
       a second rotational means is  provided on the fixture for supporting a second crankshaft for synchronous rotational positioning of the second crankshaft with the first crankshaft; and  
       a second machine head is provided having a tool, synchronously movable with the first machine head along the plunging axis to present tools to the pair of crankshafts after the crankshafts have been rotatably positioned and tilted relative to the plunging axis.  
     
     
       7. The apparatus of  claim 1 , wherein  An apparatus for machining holes in crankshafts at various angular positions about a longitudinal axis through the crankshaft and at various tilt angles to the rotational axis, comprising: 
       
         a frame:  
       
       
         a rotational means on the frame for supporting a crankshaft and for rotating the crankshaft about the crankshaft's longitudinal axis to present different angular positions for the machining of holes;  
       
       
         a machine head mounted on the frame with a tool, movable along a plunging axis to present the tool to the crankshaft to machine holes therein;  
       
       
         tilt means on the frame mounting the crankshaft to tilt the crankshaft at various angles to the plunging axis so that holes may be machined at various rotational positions about the crankshaft and at various tilt angles to its longitudinal axis; and 
       
       pivot means on the frame are provided and the tilt means comprise a fixture mounted on the pivot means for tilting about an axis through the pivot means.  
     
     
       8. An apparatus for machining holes in crankshafts at various angular positions about a longitudinal axis through the crankshaft and at various tilt angles to the rotational axis, comprising: 
       a frame;  
       a fixture on the frame having means for supporting a crankshaft for rotational positioning of the crankshaft about the crankshaft's longitudinal axis;  
       means on the fixture for turning the crankshaft in a first, angular direction about the crankshaft's longitudinal axis while the crankshaft is supported in the fixture to present different peripheral surface sections of the crankshaft;  
       a first machine head for carrying a tool, movable along three axes;  
       the first axis being a vertical axis for positioning the tool vertically relative to the crankshaft;  
       the second axis being a horizontal axis for positioning the tool horizontally relative to the crankshaft;  
       the third axis being a horizontal plunging axis which is normal to the first and second axes, for presenting the tool to the crankshaft; and  
       tilt means on the frame for tilting the fixture and the crankshaft carried thereon through a second angular rotation about a tilt axis and relative to the plunging axis to machine holes at various angles to the longitudinal axis and at various peripheral locations about the crankshaft.  
     
     
       9. The apparatus of  claim 8  further comprising:  An apparatus for machining holes in crankshafts at various angular positions about a longitudinal axis through the crankshaft and at various tilt angles to the rotational axis, comprising: 
       
         a frame;  
       
       
         a fixture on the frame having means for supporting a crankshaft for rotational positioning of the crankshaft about the crankshaft's longitudinal axis;  
       
       
         means on the fixture for turning the crankshaft in a first, angular direction about the crankshaft's longitudinal axis while the crankshaft is supported in the fixture to present different peripheral surface sections of the crankshaft;  
       
       
         a first machine head for carrying a tool, movable along three axes;  
       
       
         the first axis being a vertical axis for positioning the tool vertically relative to the crankshaft;  
       
       
         the second axis being a vertical axis for positioning the tool horizontally relative to the crankshaft;  
       
       
         the third axis being a horizontal plunging axis which is normal to the first and second axes, for presenting the tool to the crankshaft; and  
       
       
         tilt means on the frame for tilting the fixture and the crankshaft carried thereon through a second angular rotation about a tilt axis and relative to the plunging axis to machine holes at various angles to the longitudinal axis and at various peripheral locations about the crankshaft; 
       
       a second machine head having a tool, synchronously movable with the first machine head along three axes; and  
       wherein, the fixture has means for supporting a pair of crankshafts for the synchronous rotational positioning of the crankshafts about the crankshafts' longitudinal axes.  
     
     
       10. An apparatus for machining holes in crankshafts at various angular positions about a longitudinal axis through the crankshaft and at various tilt angles to the rotational axis, comprising: 
       a frame;  
       a fixture having means for supporting a plurality of crankshafts for the synchronous rotational positioning of the crankshafts about the crankshafts' longitudinal axes;  
       tilt means on the frame including trunnions mounting the fixture for tilting in an angular direction about a horizontal axis through a central portion of the fixture to present the crankshafts at various tilt angles to the plunging axis;  
       means on the fixture for turning each of the crankshafts about their respective, longitudinal axes in a second angular direction while the crankshafts are supported in the fixture;  
       a plurality of machine heads having tools, synchronously movable along three axes: the first axis being a vertical axis for positioning the tools vertically relative to the crankshafts; the second axis being a horizontal axis, parallel to the axis of the trunnions, for positioning the tools horizontally relative to the crankshafts; the third axis being a plunging axis, normal to the first and second axes, for presenting the tools to the crankshafts after the crankshafts have been rotatably positioned about both the axis of the trunnions and the crankshafts' longitudinal axes;  
       means for storing a plurality of tools and tool support bushings, adjacent the machine heads for automatic transfer of different tools and tool support bushings to the machine heads; and  
       means for positioning the tool support bushings in correct position between the plurality of crankshafts and tools.  
     
     
       11. An apparatus for machining holes in crankshafts at various angular positions about a longitudinal axis through the crankshaft and at various tilt angles to the rotational axis, comprising: 
       a frame;  
       a crankshaft workholder mounted on the frame for supporting a crankshaft for rotation about the crankshaft's longitudinal axis to present different angular positions for the machining of holes;  
       a machine head mounted on the frame with a tool, movable along a plunging axis to present the tool to the crankshaft to machine holes therein;  
       tilt means on the frame mounting the crankshaft workholder to tilt the crankshaft workholder at various angles to the plunging axis so that holes may be machined at various rotational positions about the crankshaft and at various tilt angles to its longitudinal axis; and  
       an open face on one side of the crankshaft workholder to allow loading and unloading of a crankshaft when the workholder is tilted to a crankshaft loading position.  
     
     
       12. An apparatus in accordance with  claim 11  wherein a headstock and a tailstock for rotating the crankshaft are mounted on the crankshaft workholder; and 
       means for moving the headstock relative to the tailstock to load or unload a crankshaft are on one side of the crankshaft workholder, leaving an opposite side open for lifting from an dropping into of crankshafts.  
     
     
       13. An apparatus in accordance with  claim 11  wherein an automatic tool changer is movable from a remote position to a tool changing position between the crankshaft workholder and the machine head. 
     
     
       14. An apparatus in accordance with  claim 13  wherein means on the frame guide the automatic tool changer to slide  35  laterally into a space created when the workholder is tilted to create more space between it and the machine head. 
     
     
       15. A method of machining crankshafts comprising the steps of: 
       loading a crankshaft into a pivotable fixture;  
       tilting the fixture about a first tilt axis relative to a tool-plunging axis;  
       rotating the crankshaft in the fixture about the longitudinal, axis of the crankshaft to align the hole location with the plunging axis;  
       machining a first hole in the crankshaft;  
       moving a tool head carrying a tool in three orthogonal directions relative to the crankshaft in the fixture to position the tool for machining another hole along the length of the crankshaft;  
       machining a second hole in the crankshaft; and  
       unloading the crankshaft with machined holes therein.  
     
     
       16. A method of machining crankshafts in accordance with  claim 15  including the step of  A method of machining crankshafts comprising the steps of: 
       
         loading a crankshaft into a pivotable fixture;  
       
         tilting the fixture about a first tilt axis relative to a tool - plunging axis;    
       
         rotating the crankshaft in the fixture about the longitudinal axis of the crankshaft to align the hole location with the plunging axis;  
       
       
         machining a first hole in the crankshaft;  
       
       
         moving a tool head carrying a tool in three orthogonal directions relative to the crankshaft in the fixture to position the tool for machining another hole along the length of the crankshaft;  
       
       
         machining a second hole in the crankshaft;  
       
       
         unloading the crankshaft with machined holes therein; and 
       
       loading a pair of crankshafts in the fixture and machining each of the crankshafts simultaneously.  
     
     
       17. A method of machining crankshafts in accordance with  claim 15  including the step of providing a machine tool having at least three axes with the plunging axis being a horizontal axis, and in which the step of moving the tool relative to the crankshaft includes the step of shifting the tool head vertically along a vertical axis. 
     
     
       18. A method of machining crankshafts comprising the steps of: 
       positioning a crankshaft fixture to have an open face facing upwardly to receive at least one crankshaft therein;  
       loading at least one crankshaft into the fixture through the open face thereon;  
       tilting the fixture to present the crankshaft to a tool and at a predetermined angle to the longitudinal axis of the crankshaft;  
       rotating the crankshaft in the fixture to present a predetermined location on the crankshaft to be machined;  
       plunging the tool into the workpiece to machine a hole at the predetermined location and at the predetermined angle, to the longitudinal axis of the crankshaft;  
       removing the tool from the hole formed in the workpiece; and  
       tilting the fixture to position the crankshaft for removal from the fixture.  
     
     
       19. A method in accordance with  claim 18  including the further step of providing an automatic toolchanger at a position remote from the machine head; 
       shifting the automatic toolchanger laterally into a space between the machine head and the fixture; and  
       automatically changing tools on the machine head.  
     
     
       20. A method in accordance with  claim 19  including the step of rotating the fixture to shift a portion thereof from its crankshaft presenting position for machining to enlarge the space to accommodate the automatic tool changers lateral movement to the tool changing position between the fixture and the machine head. a pivotable mount for the support and for pivoting the crankshaft carried thereon about a pivot axis and relative to the plunging axis to allow holes to be machined at various angles to the longitudinal axis and at various peripheral locations about the crankshaft. 
     
     
       21. An apparatus for machining holes in a crankshaft at various circumferential positions about a rotational axis of the crankshaft and at various angles to the rotational axis the apparatus comprising: 
       
         a frame;  
       
       
         a first support on the frame for supporting a crankshaft for rotating about the crankshaft rotational axis to present different circumferential positions for machining of holes;  
       
       
         a first drive associated with the first support for rotating the crankshaft about its rotational axis so that holes may be machined at various circumferential positions about the crankshaft;  
       
       
         a machine head mounted on the frame with a tool movable along a plunging axis to present the tool to the crankshaft to machine holes therein;  
       
       
         a second support on the frame for supporting the crankshaft for shifting relative to the plunging axis so that holes may be machined at various angles relative to the rotational axis;  
       
       
         a second drive associated with the second support to shift the crankshaft relative to the plunging axis; and  
       
       
         a mount on the frame for mounting the second support for rotating about a horizontal axis. 
       
     
     
       22. An apparatus for machining holes in a crankshaft at various circumferential positions about a rotational axis of the crankshaft and at various angles to the rotational axis, the apparatus comprising: 
       
         a frame;  
       
       
         a first support on the frame for supporting a crankshaft for rotating about the crankshaft rotational axis to present different circumferential positions for machining of holes;  
       
       
         a first drive associated with the first support for rotating the crankshaft about its rotational axis so that holes may be machined at various circumferential positions about the crankshaft;  
       
       
         a machine head mounted on the frame with a tool movable along a plunging axis to present the tool to the crankshaft to machine holes therein;  
       
       
         a second support on the frame for supporting the crankshaft for shifting relative to the plunging axis so that holes may be machined at various angles relative to the rotational axis;  
       
       
         a second drive associated with the second support to shift the crankshaft relative to the plunging axis;  
       
       
         the second support having a crankshaft loading and unloading position; and  
       
       
         the second support and crankshaft being rotated from the loading and unloading position to machine holes at various angles to the plunging axis; and  
       
       
         a mount on the frame mounting the second support for rotating the crankshaft about a horizontal axis to machine holes at various angles to the plunging axis. 
       
     
     
       23. An apparatus for machining holes in a crankshaft at various circumferential positions about a rotational axis of the crankshaft and at various angles to the rotational axis, the apparatus comprising: 
       
         a frame;  
       
       
         a first support on the frame for supporting a crankshaft for rotating about the crankshaft rotational axis to present different circumferential positions for machining of holes;  
       
       
         a first drive associated with the first support for rotating the crankshaft about its rotational axis so that holes may be machined at various circumferential positions about the crankshaft;  
       
       
         a machine head mounted on the frame with a tool movable along a plunging axis to present the tool to the crankshaft to machine holes therein;  
       
       
         a second support on the frame for supporting the crankshaft for shifting relative to the plunging axis so that holes may be machined at various angles relative to the rotational axis;  
       
       
         a second drive associated with the second support to shift the crankshaft relative to the plunging axis;  
       
       
         a second machine head having a tool for machining a second crankshaft simultaneously while the first crankshaft is machined; and  
       
       
         the first support being a work support for supporting two or more crankshafts adjacent to each other for machining two or more crankshafts simultaneously with respective holes at the same angle to the axes of the crankshafts. 
       
     
     
       24. An apparatus for machining holes in crankshafts at various rotational positions about a longitudinal axis through the crankshaft and at various angles to the longitudinal axis, the apparatus comprising: 
       
         a frame;  
       
       
         a support for supporting a crankshaft for rotational positioning of the crankshaft about the crankshaft's longitudinal axis;  
       
       
         a rotational drive carried by the support for turning the crankshaft about the crankshaft's longitudinal axis while the crankshaft is supported in the support to present different peripheral surface sections of the crankshaft for machining;  
       
       
         a first machine head for carrying a tool along a first vertical axis for positioning the tool vertically relative to the crankshaft;  
       
       
         a positioning mechanism that allows relative positioning between the machine head tool and crankshaft to be adjusted along a second horizontal axis;  
       
       
         the tool being positioned by the machine head along a horizontal plunging axis which is normal to the first and second axes, for presenting the tool to the crankshaft;  
       
       
         a pivotable mount for the support and for pivoting the crankshaft carried thereon about a pivot axis and relative to the plunging axis to allow holes to be machined at various angles to the longitudinal axis and at various peripheral locations about the crankshaft;  
       
       
         a second machine head having a tool, synchronously movable with the first machine head; and  
       
       
         the support comprising a fixture carrying a pair of crankshafts for the synchronous rotational positioning of the crankshafts about the crankshafts' longitudinal axes. 
       
     
     
       25. An apparatus for machining holes in a crankshaft at various angles relative to a longitudinal axis of the crankshaft, the apparatus comprising: 
       
         a machine head for carrying a tool that machines holes in the crankshaft;  
       
       
         a machine support that advances the tool along a plunging axis toward the crankshaft;  
       
       
         a crankshaft loading and unloading fixture having an open accessible side that can be shifted to allow for crankshaft loading and unloading operation; and  
       
       
         a drive for the fixture that shifts the open side between a first position with the open side generally facing upward to allow for overhead loading and unloading operations to take place in an unimpeded manner and a second position with the open side generally facing the machine head. 
       
     
     
       26. The apparatus of  claim 25  wherein the fixture includes a pivot axis that extends normal to the plunging axis, and the drive Pivots the fixture about the pivot axis between the first and second positions. 
     
     
       27. The apparatus of  claim 26  wherein the second position of the crankshaft fixture orients the crankshaft axis to be at various angles relative to the plunging axis for machining holes in the crankshaft at predetermined angles to the crankshaft axis. 
     
     
       28. The apparatus of  claim 25  including a crankshaft support and associated drive that allow the crankshaft to be rotated about its longitudinal axis for machining holes at different circumferential positions about the crankshaft. 
     
     
       29. The apparatus of  claim 25  wherein the crankshaft fixture has a pivot axis to allow the crankshaft to be inclined at predetermined angles relative to the plunging axis. 
     
     
       30. The apparatus of  claim 25  wherein the crankshaft fixture includes a pair of crankshaft supports for allowing a pair of crankshafts to be simultaneously loaded into the fixture or unloaded therefrom. 
     
     
       31. A method for machining holes in at least two crankshafts simultaneously with the holes being at various circumferential positions about a longitudinal and rotational axis of each of the respective crankshafts and at various oblique angles relative to the longitudinal and rotational axis of the crankshaft; the method comprising: 
         loading a pair of crankshafts into a rotatable fixture with the crankshafts disposed side - by - side and supporting opposite ends of the respective crankshafts;    
       
         rotating the fixture about an axis which is at right angles relative to a tool plunging axis to locate the axes of the crankshafts at an oblique angle to the tool plunging axis;  
       
       
         rotating the respective crankshafts while being supported by the fixture about their respective longitudinal axes to align hole locations with each of a pair of respective tool plunging axes;  
       
       
         plunging the tools along parallel tool plunging axes and machining first holes in the respective crankshafts with the holes being at an oblique angle to the longitudinal and rotational axes of the respective crankshaft, while supporting opposite ends of the respective crankshafts;  
       
       
         shifting the crankshafts relative to the plunging tools for machining additional holes in the respective crankshafts while supporting the opposite ends of the respective crankshafts;  
       
       
         machining second holes in the crankshafts with at least one of the respective holes in each of the crankshafts being at an oblique angle to the longitudinal and rotational axis of the crankshaft; and  
       
       
         unloading of the respectively machined crankshafts. 
       
     
     
       32. A method in accordance with  claim 31  comprising: 
       
         rotating the respective crankshafts along a path of travel between a changing position at which crankshafts with the holes therein are unloaded and new crankshafts are loaded and a machining position at which the new crankshafts are facing the spindles for receiving a plunging tool. 
       
     
     
       33. A method in accordance with  claim 31  comprising: 
         loading a pair of crankshafts into a side - by - side position between headstocks and tailstocks; and    
       
         holding opposite ends of the respective crankshafts between the headstocks and tailstocks. 
       
     
     
       34. A method in accordance with  claim 31  comprising: 
       
         using drills as the plunging tools; and  
       
       
         aligning drill bushings with the respective plunging drills and moving the drill bushings over the drills. 
       
     
     
       35. A method in accordance with  claim 34  comprising: 
       
         providing an automatic toolchanger at a position remote from a machine head for the drills; and  
       
       
         automatically changing drills on each of the machine heads. 
       
     
     
       36. A method of machining at least two crankshafts with tools that form oil holes at an oblique angle to a longitudinal axis of each of the respective crankshafts, the method comprising: 
       
         positioning a crankshaft support to a changing position to receive at least two crankshafts therein;  
       
         loading the crankshafts into the support with the crankshafts positioned side - by - side while at the changing position and supporting opposite ends of the respective crankshafts;    
       
         rotating the crankshafts in the support to present predetermined locations on the crankshafts to be machined;  
       
       
         shifting the tools and support relative to each other to a machining position with the crankshafts facing the oil hole drilling tools to present the respective crankshafts to the tools with the tools being at a predetermined oblique plunging angle to the longitudinal axes of the respective crankshafts;  
       
       
         plunging the tools into the respective crankshafts to machine oil holes at the predetermined locations and at the predetermined oblique plunging angle to the longitudinal axis of the respective crankshaft;  
       
       
         removing the tools from the holes formed in the crankshafts; and  
       
       
         rotating the support from the machining position to the changing position to position the crankshafts for removal from the fixture. 
       
     
     
       37. A method in accordance with  claim 36  comprising; 
       
         a changing of the crankshafts at the changing positions comprises shifting the respective headstocks and tailstocks relative to one another to release both ends of the crankshafts;  
       
       
         removing two machined crankshafts; and  
       
       
         subsequently loading two crankshafts to be machined into position between the respective headstocks and tailstocks and shifting the respective headstocks and tailstocks relative to one another to support the opposite ends of the crankshafts. 
       
     
     
       38. A method in accordance with  claim 36  wherein the relative shifting of the tools and support comprises rotating the support about an axis oriented normal to the direction of plunging of the tools. 
     
     
       39. A method in accordance with  claim 38  wherein the axis the support is rotated about is a horizontal axis. 
     
     
       40. An apparatus for machining holes in at least two crankshafts simultaneously with some of the holes being at an oblique angle to the longitudinal axis of the respective crankshafts, comprising: 
       
         a machine base;  
       
       
         a machine head carried by the base;  
       
       
         at least two spindles on the machine head, each rotatable about a first plunging axis, and each arranged to drive a separate tool and to plunge the tool into the crankshaft;  
       
       
         a fixture mounted on the machine base and rotatable about a second axis to position the respective crankshafts to allow machining of holes at various oblique angles to the longitudinal axes of the respective crankshafts;  
       
       
         clamping devices on the fixture each including a chuck and a tailstock for holding opposite ends of the respective crankshaft and for rotating the respective crankshafts about their respective longitudinal axes;  
       
       
         a drive motor associated with the chucks and tailstocks to rotate the crankshafts about their longitudinal axes to locate an area on the peripheral surface of the crankshaft to receive a hole; and  
       
       
         a motor drive for rotating the respective chucks and tailstocks with the crankshafts being held at opposite ends between a machining position in which the crankshafts are facing the spindles for machining holes therein and a changing position for changing the crankshafts by unloading the machined pair of crankshafts and loading a pair of crankshafts for machining by the respective spindles. 
       
     
     
       41. An apparatus in accordance with  claim 40  comprising: 
       
         a drill bushing positioning device associated with drill bushings for positioning the drill bushings on the respective tools. 
       
     
     
       42. An apparatus for machining holes in at least two crankshafts at various peripheral locations about each crankshaft and through the respective crankshafts at various oblique angles to their separate longitudinal and rotational axes, comprising: 
       
         a frame;  
       
       
         a fixture on the frame for supporting opposite ends of a crankshaft and a crankshaft and for rotational positioning of the crankshaft about the crankshaft's longitudinal axis;  
       
       
         a headstock and tailstock on the fixture for supporting opposite ends of the crankshafts and for turning the crankshaft in a first, angular direction about the crankshaft's longitudinal axis while the crankshaft is supported in the fixture to present different peripheral surface sections of the crankshaft;  
       
       
         a first machine head for carrying a tool and for moving the tool along a first vertical axis for positioning the tool vertically relative to the crankshaft and for moving the tool along a horizontal plunging axis which is normal to the first axis for presenting the tool to the crankshaft;  
       
       
         a slide carried by the frame and constructed and arranged to move relative to the fixture and machine head along a third axis substantially perpendicular to each of the first and second axis;  
       
       
         a drive relative to the fixture and the crankshaft carried thereon through a second angular rotation relative to the plunging axis to machine holes at various oblique angles to the longitudinal axis of the crankshaft, the holes being machined at various peripheral locations about the crankshaft;  
       
       
         a second machine head having a tool synchronously movable with the first machine head to machine two crankshafts simultaneously; and  
       
         a second headstock and tailstock or the fixture for supporting the second crankshaft side - by - side with the first crankshaft, the headstocks and tailstocks supporting crankshafts for the synchronous rotational positioning of the crankshafts about the crankshafts' longitudinal axes.   
     
     
       43. An apparatus in accordance with  claim 42  comprising; 
       
         a drill bushing positioning device associated with drill bushings for positioning the drill bushings on the respective plunging tools; and  
       
       
         an automatic toolchanger associated with the tool heads for automatically changing the tools on each of the respective plunging tools. 
       
     
     
       44. A crankshaft machining apparatus comprising: 
       
         a crankshaft having spaced ends, a main elongate portion of a predetermined length extending between the ends axially along a longitudinal axis of the crankshaft, and radially extending portions offset from the main elongate portion;  
       
       
         a machine head including a tool that forms holes in the crankshaft;  
       
       
         carriage mounts for the machine head including slides that position the tool relative to the crankshaft for a machining operation including guiding the head and tools for movement along a plunging axis toward the crankshaft;  
       
       
         a fixture having opposite end portions and a turning axis generally centrally disposed between the fixture end portions, the fixture supporting the crankshaft for shifting about the turning axis to allow the tool to machine holes in the crankshaft extending obliquely to the longitudinal axis thereof;  
       
       
         opposing crankshaft end mounts supported by the opposite end portions of the fixture for receiving the ends of the crankshaft so that the crankshaft is supported at both ends thereof with the length of the main portion of the crankshaft spanning the turning axis, and extending to the opposite end portions of the fixture with the crankshaft ends received in the end mounts; and  
       
       
         a rotary drive associated with the end mounts that rotates the crankshaft about the longitudinal axis thereof for machining the oblique holes at various circumferential positions about the crankshaft. 
       
     
     
       45. The crankshaft machining apparatus of  claim 44  wherein the carriage slides allow for movement of the machine head in a vertical y- axis direction and a horizontal fore and aft z - axis direction.   
     
     
       46. The crankshaft machining apparatus of  claim 45  wherein the carriage slides allow for movement of the machine head in a horizontal lateral x- axis direction.   
     
     
       47. The crankshaft machining apparatus of  claim 44  wherein the fixture includes two pairs of opposing crankshaft end mounts for receiving respective ends of two crankshafts, and the machine head includes a pair of tools to allow simultaneous machining of oblique holes in the crankshafts. 
     
     
       48. The crankshaft machining apparatus of  claim 44  wherein the carriage mounts and the fixture cooperate to position the tool relative to the crankshaft so that at least one of the oblique holes formed in the crankshaft extends through both the crankshaft main axial portion and one of the radially extending offset portions of the crankshaft.