US 5,558,557 A · Three axis control for machine tool

Abstract

A three axis control for a machine tool which maintains a plane surface being ground or machined by a tool at a desired orientation. A base supports an intermediate plate on flexures, and the position of the intermediate plate in a plane parallel to the base is controlled by a pair of actuators that are spaced apart along a line that is parallel to the direction of movement of the intermediate plate and a workpiece past the tool. Sensors move along a planar reference surface as the intermediate plate moves and sense deviations of the intermediate plate from a straight line and control the actuators to maintain the intermediate plate in its desired path through closed loop control. The workpiece to be worked on is preferably mounted on a tooling plate that in turn is mounted on the intermediate plate about an axis parallel to the line of movement. The position of the tooling plate about the axis is sensed by a third sensor operating on the reference surface to control an actuator that in turn controls position of the tooling plate about the axis. The sensors and controlled actuators insure that the surface of the workpiece will be planar, that is, straight and flat.

Claims17

Dependent claims

Position control apparatus for a moving machining table comprising:

a first plate adapted to be supported in a desired position relative to a rotating machine tool;
a second plate spaced from said first plate, and flexure members coupling said second plate relative to said first plate for movement in a desired plane;
a pair of actuators coupled to the second plate and controlling movement in the plane, said actuators being spaced apart along a first line in said plane;
a reference surface mounted relative to said second plate such that movement of the second plate in the plane including the first line causes corresponding movement of the reference surface;
at least two sensors mounted for sensing movement of a second line on the reference surface in direction perpendicular to the reference surface;
and
control means coupled between said sensors and said actuators for maintaining the second line on the reference surface in a desired position under control of the actuators as the reference surface moves relative to the sensor.

4 more elements

A position control apparatus for a movable machining table, wherein the table is part of a machine tool having a rotating working element for machining a workpiece, said table being movable in orthogonal directions, one direction being generally perpendicular to an axis of the rotating element, and the other direction being parallel to such axis, a mounting for a workpiece to be machined including;

a first plate mounted on the movable machining table for movement therewith;
a second plate spaced from said first plate, and flexure members coupling said second plate relative to said first plate for movement of the second plate in a plane generally parallel to the plane of movement of the machining table;
actuators for controlling movement of said second plate relative to said first plate in a plane generally parallel to a plane of movement of the machining table;
a planar surface formed on a reference member;
a pair of sensors for engagement with said planar surface and being spaced apart along a desired line on the planar surface, said sensors having means for slidably engaging the planar surface;
one of the reference members and sensors being mounted relative to the machine tool and the other of the reference member and sensors being mounted for movement with the second plate, the second plate being movable in direction transverse to the axis of the rotating element, and the sensors sliding along the desired line as the second plate moves transverse to the axis of the rotating working element;
and
a control circuit for controlling each actuator in a closed loop control from one of the respective sensors as the surface moves relative to the sensors, said actuators operating to maintain the position of the second plate as it moves in direction along the line to correct for deviation from straight line movement sensed by the sensors.

5 more elements

Dependencies are inferred from the claim text.

Three axis control for machine tool

Life of this patent

Three axis control for machine tool

Life of this patent

Abstract

Claims17