Quill drive with variable feed

Abstract

A quill drive comprising a housing adapted for mounting on machine tools. A quill is slidably mounted in a longitudinal bore in the housing, and is longitudinally positioned by a ball screw. The ball screw is driven for longitudinal positioning of the quill by a variable speed, reversible motor. The quill rotatably supports a spindle for driving various cutting tools. The spindle is advanced longitudinally by the quill and is rotatably driven by a second motor. The quill drive can be used singly or in a multiple arrangement on transfer machines or other automatic equipment. The unique design has fewer parts resulting in a simple reliable, relatively inexpensive device which is compact and easy to use. A relatively simple modification of the gear box converts the quill drive into a drive for tapping threaded holes.

Having thus described my invention, what I claim is:  .[.1. A quill drive with variable feed comprising: 
       a quill shaft slidably mounted for movement along its longitudinal axis; 
       a spindle shaft rotatably mounted for rotation with respect to said quill shaft and carried longitudinally by said quill shaft during its longitudinal movements. 
       a first motor drivably connected to an input shaft, said input shaft rotatably mounted within said spindle shaft; 
       said input shaft having disposed along its inner end a male spline; 
       said male spline drivingly engaging a female spline disposed at one end of said spindle shaft, said male spline providing rotational drive from said input shaft to the female spline of said shaft during the longitudinal movement of said quill shaft; 
       said quill shaft being of tubular construction and having attached thereto a ball nut as its inner end and within its inside diameter; 
       a ball screw threadingly engaging said ball nut, said ball screw being of tubular construction, the inside diameter of said ball screw tube surrounding but not touching the outer diameter of the inner end of said quill shaft, said ball screw extending inwardly a distance equal to the desired longitudinal travel of said quill; and 
       said ball screw being rotatably supported at its outer end and driven at its outer end by a variable speed, variable direction motor, the speed and direction of said variable speed and variable direction motor determining the direction and rate of feed of said quill..]. .[.2. The quill drive with variable feed as defined in claim 1 wherein said variable speed, variable direction motor is an electrical stepper motor..]. .[.3. The quill drive with variable feed as defined in claim 1 wherein said variable speed, variable direction motor is a hydraulic motor..]. .[.4. The quill drive with variable feed as defined in claim 1 wherein said first motor and said variable speed and variable direction motor are drivingly connected to said input shaft and said ball screw by means of gearing..]. .[.5. The quill drive with variable feed as defined in claim 1 wherein said first motor and variable speed and variable direction motor are drivingly connected to said input shaft and said ball screw by means of timing belts..]. .[.6. A quill drive with longitudinal feed comprising: 
       a quill shaft slidably mounted within one end of a housing for movement along its longitudinal axis; 
       a spindle shaft rotatably mounted for rotation with respect to said quill shaft and carried longitudinally by said quill shaft during its longitudinal movement; 
       means for longitudinally moving said quill shaft; 
       means for rotationally driving said spindle shaft; 
       an adjustable stop for fixedly establishing the maximum longitudinal motion of said quill, said adjustable stop being a ring with a threaded inner diameter, said ring being threadingly attached to the innermost end of said quill, the threaded inner portion of said quill extending along the length of said quill a distance not exceeding the length of said quill's longitudinal motion, said ring abutting the inner wall of said one end of said housing when the maximum motion of said quill is reached; 
       means for adjusting the position of said ring along the threaded length of said quill and for locking said ring in its desired position; and 
       means for stopping the extension of said quill shaft when said ring abuts said wall..]. .[.7. A tapping quill drive capable of accommodating an infinite variety of threaded pitches comprising: a quill shaft slidably mounted for movement along its horizontal axis; 
       a spindle shaft rotatably mounted for rotation with respect to said quill shaft during its longitudinal movement; 
       a spindle shaft rotatably mounted for rotation with respect to said quill shaft and carried longitudinally by said quill shaft during its longitudinal movement; 
       an input shaft for rotationally driving said spindle shaft during its longitudinal motion; 
       a drive shaft for longitudinally translating said quill shaft; 
       means for longitudinally translating said quill shaft a fixed amount per revolution; 
       means for fixing the rotational ratio between said input shaft and said drive shaft so that for one revolution of said spindle shaft said quill shaft advances a fixed amount; 
       means for varying said rotational ratio an infinite amount so that any amount of longitudinal motion of said quill per revolution of said spindle shaft is available; 
       reversible drive means for driving said spindle shaft and said drive shaft; and 
       an adjustable stop means contained within the quill housing for varying the maximum longitudinal position of said quill..]. .[.8. A quill drive with longitudinal feed comprising: 
       a quill shaft slidably mounted within one end of a housing for movement along its longitudinal axis; 
       a spindle shaft rotatably mounted for rotation with respect to said quill shaft and carried longitudinally by said quill shaft during its longitudinal movement; 
       means for longitudinally moving said quill shaft; 
       means for rotationally driving said spindle shaft; 
       said means for longitudinally moving said quill shaft comprising a ball nut fixedly attached to the innermost end of said quill; 
       a ball screw threadingly engaging said ball nut, and means for rotationally driving said ball screw; 
       an adjustable stop for fixedly establishing the maximum longitudinal motion of said quill, said stop being a ring with a threaded inner diameter, said ring threadably engaging the innermost end of said ball screw, the threaded portion of said ball screw extending along the length of said ball screw a distance, said ring abutting said ball nut when the maximum motion of said quill is reached..]. .Iadd. 9. In a variable speed quill drive including a housing having a front and a rear end and means defining an elongate bore extending through said housing from the front end thereof, a shaft rotatably mounted in said housing adjacent the rear end thereof and projecting forwardly in coaxial relationship within said bore, an elongate spindle coaxially mounted on said shaft and projecting forwardly from said shaft, spline means coupling said spindle to said shaft to accommodate axial movement of said spindle relative to said shaft and said housing while rotatively locking said spindle to said shaft, and first variable speed drive means for driving said shaft in rotation; the improvement comprising a hollow ball screw member having a threaded section substantially axially coextensive with said spline means rotatably mounted in said housing and coaxially surrounding said spindle, independent second variable speed drive means for driving said screw in rotation, a ball nut operatively received on said threaded section of said screw, an elongate hollow quill member slidably received in said bore and fixedly mounted at its rearward end upon said ball nut and projecting forwardly from said bore beyond the front end of said housing, means on said housing remote from said bore constraining said quill member against rotation within said bore, bearing means adjacent the front end of said quill member rotatably mounting said spindle within said quill member in fixed axial relationship thereto, said spindle projecting forwardly from said bearing means beyond the front end of said quill member, rotary seal means at the front end of said quill member sealingly engaged with the periphery of said spindle, nonrotary sliding seal means at the front end of said housing sealing said quill to said housing around the entire periphery of said bore, and adjustable annular stop means coaxially mounted within said bore establishing a forward end limit of movement of said quill relative to said housing..Iaddend..Iadd. 10. The invention defined in claim 9 wherein said stop means comprises an annular stop and an annular stop surface coaxially located within said bore in axial alignment with each other, said stop being threadably mounted on one of said members for adjustment axially of said one of said members, said one of said members being axially movable relative to said stop surface. .Iaddend..Iadd. 11. The invention defined in claim 10 wherein said one of said members is said quill member and said stop surface is defined by a radial shoulder in said bore. .Iaddend..Iadd. 12. The invention defined in claim 10 wherein said one of said members is said ball screw and said stop surface is defined by one end of said nut. .Iaddend.