Automatic feed device for a facing head

A facing head operable with a shank mounted on a main shaft of a machine tool, comprising a body fixed in coaxial relation to the shank and having dovetail slots extending in a direction normal to the axis of the main shaft, a tool holder slidably fitted to the body through the dovetail slots, and an operating ring fitted between the shank and the body and fixed to said machine tool, said operating ring having an internal stationary gear and also having feed pins projecting from an end face of the operating ring, an automatic feed device for automatically moving said tool holder in a radial direction during rotation of the main shaft, said automatic feed device comprising a worm shaft disposed centrally of the body and extending in a direction normal to the axis of the main shaft and the dovetail slots, clutches and worm wheels rotatably fitted to both ends of the worm shaft respectively, worm elements meshing with the corresponding worm wheels, a gear arranged in coaxial relation to one of the worm elements and meshing with said stationary gear provided at the inner periphery of the operating ring, a feed gear arranged in coaxial relation to the other worm element and operable to engage said feed pins projecting from the end surface of the operating ring, an internally threaded worm wheel fitted centrally to the body and meshing with the worm shaft, a feed screw fitted in the tool holder and arranged in parallel relation to the dovetail slots, said feed screw being threadably engaged with the internally threaded worm wheel, and a shifter connected simultaneously to the two clutches and being free to slide in a direction parallel to the axis of the worm shaft, said shifter having one operable position to engage one of said worm wheels with said worm shaft, another operable position to engage the other of said worm wheels with said worm shaft, and a further operable position where both of said worm wheels are disengaged from said worm shaft.

A facing head operable with a shank mounted on a main shaft of a machine tool, comprising a body fixed in coaxial relation to the shank and having dovetail slots extending in a direction normal to the axis of the main shaft, a tool holder slidably fitted to the body through the dovetail slots, and an operating ring fitted between the shank and the body and fixed to said machine tool, said operating ring having an internal stationary gear and also having feed pins projecting from an end face of the operating ring, an automatic feed device for automatically moving said tool holder in a radial direction during rotation of the main shaft, said automatic feed device comprising a worm shaft disposed centrally of the body and extending in a direction normal to the axis of the main shaft and the dovetail slots, clutches and worm wheels rotatably fitted to both ends of the worm shaft respectively, worm elements meshing with the corresponding worm wheels, a gear arranged in coaxial relation to one of the worm elements and meshing with said stationary gear provided at the inner periphery of the operating ring, a feed gear arranged in coaxial relation to the other worm element and operable to engage said feed pins projecting from the end surface of the operating ring, an internally threaded worm wheel fitted centrally to the body and meshing with the worm shaft, a feed screw fitted in the tool holder and arranged in parallel relation to the dovetail slots, said feed screw being threadably engaged with the internally threaded worm wheel, a shifter connected simultaneously to the two clutches and being free to slide in a direction parallel to the axis of the worm shaft to selectively engage and disengage said worm wheels with said worm shaft, and a feed pin feeding means for extending and withdrawing said feed pins from said operating ring, and including a slot at the end surface of said operating ring, stepped holes formed in said operating ring circumferentially in equally spaced relationship, said feed pins having a flange, a compression spring about each of said feed pins, said feed pins and their associated spring being disposed in said stepped holes, and a feed adjusting ring rotatably fitted in the slot formed at the end surface of the feed operating ring and having concaved portions and cams operable to engage said feed pins and to thereby extend and withdraw individual feed pins from said operating ring depending on the adjusted position of said adjusting ring.