Method of working sheet material workpieces by a sheet material working machine tool

The method of automatically running a machine tool assembly including a machine tool, an associated worktable, and workpiece gripping members movable with respect to the machine tool with the movement of the members being under control of a central automatic control which comprises the steps of:

• (a) positioning a stack of workpieces adjacent the machine tool worktable,
• (b) moving the gripping members under control from the central control to a first predetermined position exterior of a generally defined load area of said worktable,
• (c) causing a loading device to segregate a workpiece from the stack and to deposit the segregated workpiece in the load area of the worktable under command from the central control,
• (d) opening the gripping members,
• (e) moving the gripping members in a first axis direction under control of the central control into the load area to a second predetermined position,
• (f) sensing contact between the gripping members and the segregated workpiece caused by movement of the gripping members into the load area to establish a reference within the control for said first axis,
• (g) gripping said segregated workpiece by said gripping members at the second predetermined position,
• (h) thereafter moving the gripping members and segregated workpiece under control of the central control in a second axis direction different than the first axis direction and establishing a reference within the control for said second axis direction as a result of the movement of the segragated workpiece in the second axis direction,
• (i) thereafter production running the machine tool to act upon the segregated workpiece utilizing the references to reference controlled movement of the gripping members moving the segregated workpiece in the first and second axes,
• (j) completing the piece program under control of the control,
• (k) moving the segregated workpiece by control directed movement of the gripping members to an unload area of the worktable, depositing the segregated workpiece at the unload area and withdrawing the gripping members under direction of the control from the unload area,
• (l) unloading the segregated workpiece from the worktable by an unload means under direction of the control and thereafter automatically repeating steps b through l.

The method of working sheet material workpieces by a sheet material working machine tool of the type having at least one work station and a workpiece supporting table adjacent the work station for supporting a workpiece for movement in two axes directions with respect to the work station with workpiece grasping and moving means including gripper means associated with the table for moving the workpiece with respect to the work station to present selected portions of the workpiece to the work station to perform work thereon thereat, the machine tool having an automatic workpiece loading device and an automatic workpiece remainder unloading device associated therewith, said loading and unloading devices, said grasping and moving means and said machine tool being under the control of an automatic control device, which comprises the steps of:

• (a) sorting a single workpiece from a store of workpieces and loading the workpiece onto the workpiece supporting table of the machine tool by means of the loading device, said loading of the workpiece being in a general area of the table in a non-fully gauged condition of the workpiece with respect to the work station of the machine tool;
• (b) gauging the workpiece on the supporting table by moving the workpiece on the table in at least one axis direction from said general area to a gauged position;
• (c) sensing the arrival of the workpiece at the gauged position by contact between an edge of the workpiece and a sensor and inputing a signal to the control device from the sensor;
• (d) holding the workpiece at the gauged position by the gripper means with the position of the gripper means known to the control device when the workpiece is at the gauged position and the gripper means are in gripped relation to the workpiece;
• (e) thereafter using the known position of the gripper means determined in step (d) as a reference in the control device to control further movement of the gripper means and gripped workpiece;
• (f) moving the gripper means in X and Y axes directions to move the workpiece over the table to present selected portions of the workpiece to the work station;
• (g) performing work on the workpiece by the machine tool at the work station and thereby removing portions of the workpiece from remaining portions of the workpiece;
• (h) moving the remaining portions of the workpiece by the gripper means to an area for unloading;
• (i) removing the remaining portions of the workpiece from the table and from the machine tool by the unloading device, and
• (j) repeating all of the steps (a) through (i) on successive workpieces under control of the control device.

The method of performing work on a sheet workpiece by a controller controlled machine tool having a working station at which a tool acts upon a workpiece, a workpiece support table adjacent to the work station, a workpiece movement gripper assembly having workpiece grippers, and associated with the table and controlled by said controller for controlled movement of the workpiece on the workpiece support table by the gripper assembly to present successive selected portions of the workpiece to the working station, and a loader for loading workpiece sheets a single sheet at a time from a stack of such sheets onto the worktable, which comprises the steps of:

• (a) loading a single workpiece sheet onto the worktable and depositing the sheet on the worktable by the loader in a non-fully gauged position of the sheet on the worktable where the relative position of any two edges of the sheet normal to one another is not known to the controller, the relative position being in relation to a base line system for controlled movement of the sheet by the grippers;
• (b) moving the workpiece on the worktable under command of the controller by automatic means from the non-fully gauged position to a fully gauged position with the automatic means under the control of the controller;
• (c) sensing the arrival of the workpiece at the fully gauged position by sensor means having a position known to the controller at the time of sensing and inputting a signal to the controller from the sensor means, the signal indicating the presence of at least a portion of the sheet at the sensor means position, the fully gauged position being a position where the position of at least portions of two edges of the sheet normal to one another are known to the controller;
• (d) the grippers gripping the workpiece at the fully gauged position with the position of the gripper assembly known to the controller when the workpiece is at the fully gauged position and the grippers are gripping the workpiece;
• (e) and thereafter moving the workpiece on the worktable relative to the work station by causing movement of the gripper assembly under command of the controller using the position of the gripper assembly at the position of step (d) as a reference position for the controller for commanding said last mentioned movement.

A method of processing and handling a workpiece in a fully automatic machine tool under the control of a controller, comprising the steps of:

• separating a sheet of material from a stack of material adjacent a worktable for the machine tool;
• moving the separated sheet to a first position on the worktable in an ungauged position;
• moving the sheet on the worktable from the ungauged position to a fully gauged position automatically by means under the control of said controller;
• sensing the presence of the sheet at the fully gauged position by sensors carried in association with the worktable;
• locating within the controller the position of grippers when the sheet is at the sensed fully gauged position by inputing a signal to the controller from the sensors, the controller knowing the position of the grippers when the signal is inputed;
• causing the grippers to grip the sheet at said sensed fully gauged position with the grippers at a position which is the position located within the controller;
• moving the sheet with respect to the work station of the machine tool by the grippers and performing work on the sheet by the machine tool with the controller referencing movement of the grippers in relation to the position of the grippers as located in the controller.

A method of processing and handling a workpiece in stages in a fully automatic machine tool, and with a controller controlling the charging and removal of the workpieces onto or away from the machine tool and the handling of the workpiece in the machine tool, including charging a workpiece individually from a stack of the workpieces onto a worktable, acting upon the workpiece by means of a tool at a work station associated with the worktable, handling the workpiece by means of grippers which are movable in the X and Y axis relative to the worktable while selected portions of the workpiece are moved into the work station, removing the workpiece from the worktable after acting on the workpiece by the machine tool, and coordinating the processing and handling stages with each other by the controller, comprising:

• depositing the workpieces freely on the work table in a general area thereof in a not fully gauged position adjacent to workpiece grippers;
• automatically moving the workpiece on the worktable from said general area by command of the controller to a fully gauged position in accordance with signals from a gauge arrangement associated with the worktable;
• sensing the presence of the workpiece at the fully gauged position by engagement with sensors;
• and
• gripping the workpiece at the fully gauged position with the grippers imparting knowledge of the position of the grippers relative to the workpiece to the controller when the workpiece is at the fully gauged position.