Abstract:
The tool change mechanism includes a tool storage magazine having a plurality of tool storage sockets disposed in two concentric circles. A tool transfer arm is mounted within the inner circle of sockets. The transfer arm may be rotated and extended or retracted and moved toward and away from the magazine for extracting a previously used tool from a ready socket and inserting such tool into a designated socket of the magazine. In like manner, the transfer arm will operate to extract a selected tool from any one of the sockets in the magazine and transfer it to the ready socket. The latter is mounted on a carrier which also supports a tool change arm. The carrier is pivotable between a loading position and a tool change position. When the carrier is in the loading position, the ready socket is located at the magazine where it is accessible to the tool transfer arm for extracting previously used tools from the ready socket and inserting new tools into it. On the other hand, when the carrier is in the tool change position it is located adjacent to the spindle in position to enable the tool change arm to interchange tools between the ready socket and the spindle.
Abstract:
A pair of substantially identical shuttle tables are mounted on the bed of a vertical spindle machine tool on opposite sides of the worktable thereof. A first pallet is mounted on the worktable and a second pallet is mounted on one of the shuttle tables. Both pallets have a tunnel therein that extends all the way through the pallet. A hydraulic ram with an elongated piston rod is mounted on each shuttle table. Each piston rod is long enough to pass completely through the tunnel in an adjacent pallet and to bear against a pallet on the worktable while the base of the piston rod bears against the adjacent pallet. When the piston rod is extended, both pallets are simultaneously pushed in the same direction so that the pallet on the worktable is shifted to the empty shuttle table while the pallet on the other shuttle table is shifted onto the worktable. When the piston rod is subsequently retracted, both pallets remain in their shifted position. When the other piston rod is extended, both pallets are simultaneously pushed back to their original positions.
Abstract:
In apparatus for controlling the speed and torque of a multiphase a. c. motor in accordance with digital control signals, a first regulation circuit regulates the frequency of the a. c. electrical signal applied to the motor and another regulation circuit regulates the voltage of the a.c. signal. Both regulation circuits are controlled by digital control signals in a series of discrete steps over a range of control values and the control signals are supplied periodically to the regulation circuits. The speed and torque are controlled in accordance with an algorithm relating speed and torque to the frequency and voltage of the source of electric power which is applied to the motor, calculated by computing apparatus on a periodic basis. In one embodiment the position of the magnetic flux of the stator is controlled directly.
Abstract:
The cutting force applied between the cutting tool and the workpiece of a machine tool is periodically pulsated to expedite removal of material from the workpiece. The periodic cutting force pulsation is produced by periodically varying the spindle speed or the feed rate or both. In one embodiment, the periodic speed variation is produced by universal joints in the spindle drive and worktable drive. In a second embodiment, the periodic speed variation is produced by elliptical gears in the spindle drive and worktable drive.
Abstract:
In apparatus for controlling the speed and torque of a multiphase a.c. motor in accordance with digital control signals, a first regulation circuit regulates the frequency of the a.c. electrical signal applied to the motor and another regulation circuit regulates the voltage of the a.c. signal. Both regulation circuits are controlled by digital control signals in a series of discrete steps over a range of control values and the control signals are supplied periodically to the regulation circuits. The speed and torque are controlled in accordance with an algorithm relating speed and torque to the frequency and voltage of the source of electric power which is applied to the motor, calculated by computing apparatus on a periodic basis. In one embodiment the position of the magnetic flux of the stator is controlled directly.
Abstract:
A machine tool operative as both a chucking type lathe and as a horizontal spindle machine center comprises a rotatable spindle horizontally journaled to a spindlehead vertically reciprocal on a machine tool upright, the upright being slidably mounted for movement on one leg of an "L" shaped bed. A saddle, mounted for movement along the other leg of the bed, carries a table rotatably journaled therein. Affixed to the table is a tailstock which carries both toolholders and workpiece holders. A changer arm, journaled to the spindle for rotation about, and linear movement along, an axis parallel to the axis of spindle rotation is operative, when the upright is moved along the bed to a first changer position, to transfer toolholders and workpiece holders between the spindle and a storage drum journaled to the bed for rotation about an axis parallel to the axis of spindle rotation. The changer arm is also operative, when the upright is moved to a second change position distal from the storage drum and when the saddle is moved and table is rotated, to position the tailstock along the side of the spindle, to transfer toolholders and workpiece holders between the spindle and the tailstock. In this way, a turning operation can be accomplished by transferring a turning tool to the tailstock and a workpiece holder to the spindle. A machining center operation is effectuated by transferring a workpiece holder from the spindle to the tailstock and by transferring a cutting tool from the storage drum to the spindle.
Abstract:
A rotary table is driven by a pair of perpendicularly disposed linear slides which are each driven by a ballscrew drive. One of the linear slides is mounted on the movable member of the other linear slide and is coupled to the rotary table by a crank stud. The linear slides are driven at speeds which vary in accordance with the sine and cosine of the table angle to translate the linear slide motion into rotary motion.
Abstract:
A tool changer drum is rotatably mounted on a machine tool for rotation about an axis which is perpendicular to the spindle axis thereof. A plurality of tool changer arms are swingably mounted on the tool changer drum for swinging movement along radii of the drum between a storage position parallel to the central plane of the drum and a transfer position perpendicular to the central plane of the drum. A pneumatic cylinder is used to index the tool changer drum to place any selected tool changer arm in the ready position. Another pneumatic cylinder is used to swing the ready tool changer arm from its storage position to its transfer position to transfer a toolholder from storage to the spindle and later to swing the tool changer arm back to the storage position to return the toolholder to storage. Before the tool transfer operation, the spindle is moved to a tool transfer position in which the swinging movement of the tool changer arm either places a toolholder in the spindle or removes a toolholder therefrom.