Erowa Ag

Ateliers Des Charmilles S.a.

Charmilles Technologies S.a.

Rudolf Schneider

Niklaus Liechti

Jean Pfau

Alain Wavre

Joseph Josserand

An apparatus for clamping workpieces which have to be machined by a machine tool. The apparatus comprises a rectangular frame including two longitudinal frame members and two transverse frame members. Clamping means are provided to fix the workpieces to be machined to said rectangular frame. The clamping means comprise at least one auxiliary frame which is removably inserted in said rectangular frame. Each of the auxiliary frames includes two clamping bars which can be adjustably connected to each other and the ends thereof being adapted to be connected to the longitudinal frame members of the rectangular frame such that they are adjustable in the longitudinal direction of the longitudinal frame. The clamping bars comprise a plurality of continuous threaded bores running essentially perpendicular to the clamping bars, said bores being enlarged to a predetermined nominal diameter and said bores being adapted to selectively receive a clamping screw.

Apparatus for clamping workpieces which have to be machined by a machine

The driving apparatus for the rotation of the spindle or the work piece pallet of an electroerosive machining device comprises two electric motors which drive e.g. the spindle to a rotational movement by means of two gear boxes and a plurality of gear wheels. In order to avoid any backlash in the gear box and any clearance between the gear wheels and to compensate the elasticity of the gear transmission, the two electric motors are always operated to rotate in opposite directions and/or to yield different values of torque. Thus, the entire transmission assembly is always subjected to a certain bias force so that a precise positioning of the spindle is possible by means of simple and inexpensive driving elements.

Apparatus for driving a spindle of an electroerosive machine

The invention provides a screw nut comprising a central inner thread and a radially extending slit, the width thereof essentially corresponding to the diameter of the central inner thread. Thus, a threaded bolt or a threaded stud can be radially inserted into said screw nut body. In order to avoid that the screw nut is displaced away from the threaded bolt or stud during tightening of the screw nut, the central inner thread comprises a plurality of thread turns provided with axially extending recesses directed towards the end surface of the screw nut which is under load when the screw nut is tightened on the threaded bolt or stud.

Radially insertable screw nut

The invention provides an apparatus for fixing a workpiece to be machined by a machine tool to the worktable of the machine tool in an exactly determined positional relationship with reference to a reference point located on the worktable of the machine tool. The apparatus of the invention comprises a workpiece receiving means adapted to removably receive the workpiece to be machined, and first positioning means comprising a first group of positioning apertures provided in the workpiece receiving means, and a first group of positioning studs provided on the worktable of the machining tool, said first group of positioning apertures and said first group of positioning studs cooperating to determine the position of the workpiece receiving means in X- and Y-direction. Further, there are provided second positioning means comprising a second group of positioning apertures and a second group of positioning studs, said second groups of positioning apertures and positioning studs being located distantly from said first groups of positioning apertures and positioning studs and cooperating with each other. The cooperating second groups of positioning apertures and positioning studs determine the position of the workpiece receiving means either only in X-direction or only in Y-direction, but not simultaneously in both directions.

Apparatus for fixing a workpiece to the worktable of a machine tool

The invention provides a manufacturing jig to precisely position a workpiece with reference to a workpiece receiving means. The jig comprises a workpiece supporting member to which the workpiece is fixed and a receiving member on which said workpiece supporting member is releasably mounted. The receiving member comprises two registering pins protruding from one surface thereof. The workpiece supporting member comprises two centering apertures adapted to engage the two registering pins upon mounting the workpiece supporting member on the receiving member. The two centering apertures are located distantly to each other. The first centering aperture has a fixed position with reference to the workpiece supporting member and the second centering aperture is displaceable with reference to the workpiece supporting member in a direction along a tie line between the centers of the first and second centering apertures, but movable in a direction running perpendicular to said tie line.

Manufacturing jig

The invention refers to a tool or workpiece storing magazine incorporating a tool- or workpiece-change apparatus adapted to remove a tool or a workpiece from the magazine and to transport the it into a machining apparatus, and to remove a tool or workpiece from the machining apparatus and to transport it back to the storing magazine, respectively. The system comprises a plurality of essentially disc-shaped tool or workpiece supporting members rotatably and coaxially arranged with reference to a first axis of rotation which receive and support a plurality of tools or workpieces along the periphery thereof. A transport arm is pivotally mounted on a second axis of rotation and longitudinally displaceable along said second axis located in a certain distance from said first axis of rotation. The transport arm is adjustable with reference to its length and includes a gripping member mounted on its free end. The transport arm further includes a turning knuckle, the axis thereof extending in an angle of 45.degree. with reference to the length adjustment direction of the transport arm, and a transport arm element, one end thereof being connected to said turning knuckle and the other end thereof bearing said gripping means, whereby the transport arm element means is generally L- or arc-shaped.

Tool-change and workpiece-change apparatus

The measuring apparatus comprises a base plate member including a rotatable measuring object receiving station adapted to rotatably receive e.g. a tool to be measured. Besides the receiving station, a guiding column is arranged having a guiding rail along which a measuring carriage is movable upwardly and downwardly. The carriage is provided with a horizontally displaceable measuring rail, an end portion thereof being equipped with a measuring calliper assembly. This assembly includes a measuring calliper with a calliper head which may be brought into contact with the tool to be measured. The calliper head is displaceable with regard to a calliper portion fixed to the end portion of the measuring rail. A force acting on the calliper head in horizontal direction (e.g. towards the right) causes the same displacement of the calliper head as a force acting on the calliper head in vertical direction (e.g. upwardly). The displacement is determined by means of a measuring gauge. With the measuring apparatus of the invention, objects may be measured in three dimensions without the need to constructionally change or readjust the apparatus.

Measuring apparatus to determine the dimensions of an object in three

The invention refers to a tool assembly for cuttingly machining of an at least partially closed inner surface of a workpiece, e.g. a bore. It comprises an essentially rod-shaped tool support having a machining tool mounted on its end and which is adapted to be inserted into the cavity to be machined. The tool support comprises a rod member with a continuous opening extending in axial direction and with parallel supporting surfaces arranged in the region of the both ends and extending with an angle to the longitudinal axis of the rod member. A machining tool supporting member having a machining tool mounted at one end is slidably mounted at one end of the rod member and rests against the first supporting surfaces of the rod member. A control member is slidably mounted at the other end of the rod member perpendicularly to the axis of the tool support and resting on the second supporting surface, serving for the pushing-out and retiring of the tool supporting member. To this purpose a connecting member extending through the opening of the rod member is provided, being connected, with its one end, to the machining supporting member and, with its other end, to the control member, thereby coupling these elements together in a predetermined distance.

Machining tool assembly

The measuring calliper provides for the determination of two perpendicular linear dimensions of a workpiece by means of the same measuring apparatus. It comprises a calliper body consisting of two portions which are displaceable with reference to each other. A calliper head, which is engageable with the workpiece to be measured and is operatively coupled to the measuring apparatus, is mounted on a first portion. The second portion is connected to the first portion by means of elastically resilient connection members which extend at an angle of 45.degree. with reference to the measuring directions. Preferably, the calliper body is a one-piece construction and is subdivided into said first and second portions by means of slots provided in the calliper body and extending at an angle of 45.degree..

Measuring calliper

A method and apparatus for threading the electrode wire of a travelling wire EDM apparatus through an aperture in a workpiece. Prior to automatically threading the wire through the aperture in the workpiece, the wire is continuously straightened by pulling longitudinally on the wire, and the wire is passed through a guide tube and through a nozzle to which fluid under pressure is supplied for forming a jet stream at the outlet of the nozzle. Prior to a threading or rethreading operation the wire is cut off proximate to the outlet of the nozzle. The nozzle outlet is brought in close proximity to the aperture in the workpiece and the jet stream is aimed at the aperture in the workpiece for guiding the wire through the aperture, while being maintained coaxially by the jet stream. The consecutive steps for feeding the end of the wire through an aperture in the workpiece are effected in sequence for initial threading of the wire through a pre-drilled stating hole in the workpiece, or for rethreading the wire through a cut in the workpiece after accidental rupture of the wire during a cutting operation.

Process and mechanism for threading the electrode wire of an EDM

The invention provides a clamping apparatus, particularly for receiving and clampingly retaining electrode body blanks having prismatic or circular cross section for erosive machining devices. A clamping block has at one of its surfaces an essentially centrally arranged clamping chamber to receive the electrode. Two adjacent walls of the clamping chamber are provided with clamping screws protruding into the clamping chamber. An approximately central position of the workpiece in the clamping chamber is achieved by the provision of distance plates with preselectable thickness, which are inserted into the clamping chamber between two walls thereof and the surface of the workpiece, before the workpiece is clamped by tightening the clamping screws. This clamping apparatus is inexpensive and rugged, so that the electrode, once machined and used, respectively, may always remain clamped and therefore may be used again with a very high precision as far as its position is concerned.

Apparatus for the clamping of elongate workpieces

The invention provides a coupling device with a first, driven member and a second member to be driven by the first member to a rotational movement. A driving plate is arranged between the two members and fixedly connected to the second member. In order to provide an angularly and centrically well defined position of the two members relative to each other, said first driven member is equipped with a centrically as well as an eccentrically arranged driving pin, the outer surfaces thereof having at least partially a conical shape. The conical parts of the surfaces engage with openings correspondingly arranged in the driving plate, which is elastically deformed upon connection of the second member to the first member.

Coupling device

A method and apparatus for threading the electrode wire of a travelling wire EDM apparatus through an aperture in a workpiece. Prior to threading the wire through the aperture in the workpiece, the wire is continuously annealed and straightened and is passed through a nozzle to which fluid under pressure is supplied for forming a jet stream at the outlet of the nozzle. Prior to a threading or rethreading operation the wire, which is continuously fed by pulling by a wire conveyor mechanism, is cut off proximate to the outlet of the nozzle. The jet stream is aimed at the aperture in the workpiece and the end of the wire is fed through the aperture, while being maintained coaxially by the jet stream. The consecutive steps for feeding the end of the wire through the aperture in the workpiece are effected in sequence for first threading the wire through a pre-drilled starting hole in the workpiece or for rethreading the wire through a cut in the workpiece after accidental rupture of the wire during a cutting operation.

In electro-erosive machining apparatuses with multidimensional relative motion between a tool-electrode and a workpiece electrode, a simple and adaptable control is provided for these relative operating movements, with a superimposed shaping-limiting control and subordinated cyclic repetitive oblique erosion. In this connection, the tool-feed is limited, within individual oblique-erosion cycles, by achieving a predetermined shaping envelope-surface. The apparatus comprises two separate coordinating-function-transmitters by means of which two operating movements, at an angle to each other, are each determinable according to a resultant relative operating movement between the tool and the workpiece, one being used for shaping-limiting control and the other for oblique erosion. Initiation of the consecutive oblique-erosion cycles is effected by means of a repetition-circuit as a function of a rated-value/actual-value approximation of the shaping-limiting control.

Electro-erosive processing apparatus

In swinging wire guides for generally conical finishing surfaces, the problem exists of a reliable automatic coaxial setting of the guide axes according to the particular angular position of the wire electrode in the workpiece finishing zone. As a solution, the wire guides (DF1, DF2) supported swinging on the support elements (TO1, TO2) are joined together by a coupling device, which has a guide member (FG) joined correspondingly with the support elements. The latter is set by the relative movement of the wire guides (DF1, DF2) to the desired angular position of the wire guides according to the ideal wire guide axis (D--D). Through swinging coupling gears (SK1, SK2) the angle position of the guide member (FG) is transmitted to the wire guides (DF1, DF2). These coupling gears suitably contain a jointed parallelogram (LK) and a rotary coupling member (DK) for the transmission of two swinging movement components, perpendicular to each other, in the sense of a total biaxial forced coupling of the guide member with the wire guides.

Growing community of inventors

Reinach, Switzerland

Rudolf Schneider