Radial feed facing head for boring bar
View Patent ↗A portable boring/facing machine using a single drive motor for rotating a boring bar and for either axially translating a cutting head assembly along the bar or radially moving the blade of the cutting head assembly using a lead screw. The machine utilizing two mounting brackets is attachable to the workpiece for alignment with the workpiece.
1. A metal working machine for reboring or refacing a workpiece comprising, in combination:
(a) an elongated, generally cylindrical boring bar, the boring bar having a longitudinally extending groove formed inward from an exterior surface thereof;
(b) an elongated feed screw journed for rotation within said groove;
(c) first and second helical gears coaxially mounted on the feed screw, the first helical gear being slidable on the feed screw and the second helical gear being threaded on the feed screw;
(d) an annular cutting head assembly disposed about the boring bar and rotatable therewith, the annular cutting head member having a slide supporting a tool block that is adapted to be moved in a radial direction with respect to a longitudinal axis of the boring bar;
(e) a radial feed screw journaled for rotation on the slide and engaging a nut affixed to the tool block and a first miter gear keyed to the radial feed screw;
(f) a control shaft disposed parallel to the longitudinal axis of the boring bar and journaled for rotation in the cutting head assembly, the control shaft supporting a third helical gear that meshes with the first helical gear and a fourth helical gear that meshes with the second helical gear;
(g) a connector shaft coaxially aligned with the control shaft and having a second miter gear keyed to it to mesh with the first miter gear; and
(h) a lock mechanism slidable on the control shaft for selectively locking and releasing the third and the fourth helical gears whereby locking the third and fourth helical gears from rotation while driving the feed screw translates the cutting head assembly along the boring bar and releasing the third and forth helical gears for rotation while driving the feed screw drives the radial feed screw while maintaining the cutting head assembly stationary.
2. The metal working machine as in claim 1 and further including means for positively locking the cutting head assembly to the boring bar.
3. The metal working machine as in claim 1 wherein the elongated feed screw includes a pair of flat surfaces running along substantially the entire length thereof.
4. The metal working machine as in claim 3 wherein the first helical gear includes flat surfaces on an internal diameter for engaging the pair of flat surfaces on the elongated feed screw to permit sliding of the first helical gear on the elongated feed screw and rotation of the first helical gear with the elongated feed screw.
5. The metal working machine as in claim 1 wherein the lock mechanism includes a frusto-conically tapered end portion on said connector shaft and a screw actuated retainer plate having a bore formed therein for receiving the tapered end portion with a predetermined frictional fit when the retainer plate is displaced in a first direction.
6. The metal working machine as in claim 5 and further including a taper lock operatively associated with the third helical gear and a frusto-conical projection on the retainer plate adapted to engage the taper lock when the retainer plate is displaced in a second direction opposite the first direction.