Patent ID: 9289870
Filing Date: 2016-03-22
CPC Classification: B23B,B23Q,F16L,Y10T

Claim Text:
1. A boring apparatus comprising: a feed screw mounted to rotate about its axis having a first planetary gear assembly at its proximal end, a cutting head and boring bar coaxially mounted on the feed screw by a feed nut whereby rotation of the feed nut by one full rotation relative to the feed screw causes movement of the cutting head by a distance P along the axis, a tubular drive shaft coaxially mounted around the boring bar, operably connected to the boring bar to rotate the boring bar about its axis and to permit relative axial movement between the boring bar and the tubular driveshaft, and having a second planetary gear assembly at its proximal end, situated adjacent to and distally situated with respect to the first planetary gear assembly, a drive motor operably connected to rotate the tubular drive shaft, boring bar and cutting head at a cutting rotation velocity, from zero up to a maximum cutting rotation velocity, about the axis, wherein each of the first and second planetary gear assemblies has a central sun gear, around which one or more planetary gears orbit, and an annular ring gear, which surrounds both the sun gear and the one or more planetary gears; carriers of the planetary gears of the first and second planetary gear assemblies, which are rigidly interconnected, whereby the carriers rotate in unison about the axis, wherein a primary feed motor is arranged to drive a primary feed drive shaft operably geared to a face of a ring gear of one of the planetary gear assemblies whereby that planetary gear assembly is rotatably drivable by the primary feed motor to act as a primary feed planetary gear assembly, and wherein the ring gear of the other planetary gear assembly is arrangeable to be held with zero rotational speed or to be independently rotatable about the axis.