Renishaw Plc

Jonathan S Sullivan

David R McMurtry

Graham A Hellen

Stephen E Lummes

Andrew J Harding

Martin P Spivey

A coordinate measuring machine carries a modular touch trigger probe 100, via an adaptor 200, on its movable arm 10. The probe 100 consists of a retaining module 102 which is mounted to the adaptor 200, and a stylus module 104 which is magnetically connected to the retaining module 102 in a manner which enables the exchange of one stylus module 104 for another. The adaptor consists of a pair of coupling members 202,204 which are urged into mutual engagement by magnets 212. Automatic exchange of stylus modules occurs by using movement of the arm 10 to disengage a stylus module 104 from the retaining module 102. Similarly, the exchange of one probe for another is carried out by using movement of the arm 10 to disengage the lower coupling member 204 from the upper coupling member 202. Because magnetic attraction between the coupling members 202,204 is necessarily greater than the attraction between retaining and stylus modules 102,104, lower coupling member 204 has three levers 222, operable by downward relative movement of a release ring 220, which occurs during uncoupling. The levers 222 provide the mechanical advantage necessary to enable movement of the arm 10 to overcome the relatively large magnetic attraction force between coupling members 202,204.

Inspection system for coordinate positioning machine

To provide a better seal for example in an indexing arm for a machine tool to prevent swarf getting to the rubber seal, an outer spring seal is provided. The seal takes the form a closely wound coil spring formed into a ring and positioned in a slightly expanded state in a vee-grove at the entrance to the space being sealed. The spring is compliant enough to allow for slight axial and transverse relative movements of the two parts of the arm and is hard enough not to be damaged by swarf or the limited relative rotation between the parts during indexing.

Seal assembly having first and second seals acting in series

An arm 12 for holding a tool-setting probe 14 in a machine tool is rotatable between an operative position and an inoperative position. The operative position is defined by elements 48,52 which form a stop against further rotary motion beyond the operative position. These elements 48,52 are arranged as a kinematic support, so that the operative position is defined in a precisely repeatable manner. Springs 40 urge the elements 48,52 together. When the arm is in the operative position, these springs are stretched by a repeatable amount, so that they provide a repeatable force, in order to increase the precision of the operative position.

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Farnborough, United Kingdom

Jonathan S Sullivan