Metal working – Method of mechanical manufacture – Work holding
Reexamination Certificate
1999-08-09
2001-09-25
Hail, III, Joseph J. (Department: 3723)
Metal working
Method of mechanical manufacture
Work holding
C269S008000
Reexamination Certificate
active
06292998
ABSTRACT:
BACKGROUND OF THE INVENTION.
1. Field of the Invention.
The invention, in general, relates to a method and an apparatus for mechanically processing of workpieces and for assembling and disassembling of structural units and, more particularly, to an apparatus in which workpieces to be processed, or structural units to be assembled or disassembled, as the case may be, are secured on an adjustable and, optionally, removable clamping tray of the kind integrated in such machine tools as, for instance, CNC-controlled grinding machines, milling machines, boring mills and the like, or utilized in transfer lines for assembling or disassembling structural units.
2. The State of the Art.
To reduce idle times during mechanical processing, assembly or disassembly operations, and to increase productivity and manufacturing capabilities, it is common practice to incorporate individual machine tools or even entire machine systems into assembly or disassembly lines. Proposals aimed at satisfying these requirements have not been lacking. They have been addressed to such operations as securing and releasing workpieces on workpiece clamping trays, aligning workpieces relative to processing tools, positioning workpieces for purposes of processing, as well as to motors accommodating such operations.
For instance, German patent DE 21 02 234 A1 relates to a drive for moving, within an assembly line, tool supports into predetermined positions in a transport path. To this end, a plurality of primary and secondary components of conventional linear motors is used cooperating alternatingly and by pulsed energization. The primary components are disposed in spaced relationship along a transport path, either singly or in groups. The secondary components are mounted on the tool support.
Grouped primary components are aligned either in parallel or angularly with respect to each other, and predetermined primary groups are connected in a consecutive sequence to a source of three-phase or direct current by means of switches actuated by the tool support. Each the secondary components consists of a plate of high magnetic conductivity and, when facing a primary component, and which is covered by an electrically highly conductive plate. Both secondary components are longer than any one of those primary components which are disposed in the same manner as they are.
Two parallel strips of high magnetic conductivity are embedded in the plate of high electric conductivity and extend laterally thereof. Each one of the strips is wider than the width of notches of the primary components and the center spacing between them which corresponds to the spacing between two opposite poles of the primary components.
In such an arrangement an air cushion is built up between the tool support and the transport path, and a conventional linear motor is utilized as a drive.
Clamping or lifting of workpieces by means of a magnetic clamping tray is known from European patent EP 0,357,904 A1 which describes a magnetic clamping tray capable of securely retaining not only workpieces made from different materials, but also workpieces made from weakly and non-magnetic materials. Its surface is structured such that it supports a workpiece in any position; at the same time it ensures appropriate vacuum pressure by an unimpeded air flow.
Two embodiments are described. In one embodiment slots or bores are formed in the magnetic pole sections between pole conduits which are made of non-ferromagnetic material and which are filled with a fine porous sintered metal.
In the other embodiment, the slots are provided in the pole conduits and are also filled with a fine porous sintered metal which in this case, however, is not ferromagnetic.
While it is possible magnetically to secure a workpiece with the described combination vacuum and magnetic clamping tray, it is not possible, for instance, to align or move a workpiece provided on the magnetic clamping tray.
Furthermore, German patent DE 196 28 921 A1 discloses a machine tool system for mechanical operation which consists of a machine base in operative connection with a gantry supported laterally of the foundation of the machine and extending over the machine base. The base of the machine is provided with a bed for receiving and supporting a clamping device. The receiving bed may be moved in the direction of the longitudinal or x-axis of the machine.
The receiving bed is provided with a clamping device which may be magnetically supported, arrested and positioned and which workpieces to be secured on the clamping tray. The entire clamping device may be magnetically lifted, moved and positioned. It may also be lowered and magnetically clamped, preferably by hybrid magnets, on the receiving bed.
It is also known to structure the clamping tray of such a clamping device for movement and adjustment not only along its x and y axes, but also for angular movements and adjustments about its vertical axis, by appropriate lifting and adjustment devices.
In these known arrangements,lifting magnets move the clamping devices with workpieces placed thereon are put into a floating state which state they may be adjusted, positioned and lowered to be secured by arresting magnets. With the clamping tray in this lowered and secured position, the workpieces may be subjected to defined processing operations.
It is an object of the invention to provide a method and an apparatus capable of performing mechanical processes and operations on workpieces and of assembling or disassembling, as the case may be, structural units, and of positioning workpieces or structural units placed on a clamping tray of a machine system relative to tool systems, assembly devices, processing systems and the like which are disposed on one or more gantries which extend over, or are arranged around, the clamping tray.
SUMMARY OF THE INVENTION.
In a currently preferred embodiment there is provided a method of performing mechanical operations on workpieces and of handling structural units to be assembled or disassembled in which the workpieces or structural units are secured on fixed or removable workpiece clamping trays which as part of a clamping device or turntable may be supported in a floating state, adjusted and positioned by magnetic forces and/or pneumatic and/or hydraulic media. The workpieces secured on the clamping tray may be subjected to rotational processing in the floating as well as in the lowered position of the clamping device or of the rotor of the turntable. A sensor system is provided for ensuring no contact between the support elements of the clamping tray and a magnetic support ring or between the support elements of the rotor with its clamping tray and the housing of the turntable. Positioning of the workpieces or structural units relative to tool, assembly or disassembly systems at a precision in the pm range is ensured by a measuring and closed-loop control system. Direct angular positioning and measurement of rotational velocity and indirect measurement of the acceleration of the rotor are provided by an angle measuring device.
The apparatus in one embodiment of the invention is structured as a clamping unit consisting of a base plate with an associated support ring provided with a device for adjusting the angle of inclination which in turn is connected to a centering plate and a workpiece clamping tray by means of adjustment spindles. The base plate which may be a solid plate or a ring is disposed within a magnetic support ring provided with an apertured medium chamber and a nozzle system consisting of individual nozzles arranged around the periphery of the magnetic support ring.
In another embodiment of the invention there is provided a turntable consisting of a housing, a magnetically supported rotor including a fixed or removable clamping tray, lifting magnets, arresting magnets, centering magnets, a linear motor as well as an angle measuring device and a sensor system.
Advantageously, the method in accordance with the invention provides for mechanically processing, treating, coating, assembling or disassembling and the like
Hail III Joseph J.
Hormann Karl
Sharley Daniel
w.i.t.—Wiemers innovative Technik GmbH.
LandOfFree
Method and apparatus for processing workpieces and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for processing workpieces and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for processing workpieces and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2515910