Siemens Aktiengesellschaft

Reiner Mueller

Horst Kippenberg

Joachim Grosse

Wilfried Kuhl

Ruediger Hess

Klaus Lukas

Ernst-Ludwig Hoene

Thomas Moser

Heinrich Haessler

Wolfgang Schlenk

Elmar Sommer

Norbert Proelss

A method and an apparatus protect location-related messages which are transmitted from a provider to a plurality of temporally changing recipients and receiver devices in a plurality of localities in each case. The method and apparatus are distinguished by the fact that key certificates for signed messages are issued only in a location-related manner and are thus valid only in a particular defined local environment.

Method and apparatus for authenticating location-related messages

Contact arrangement for vacuum switches with axial magnetic fields

A method for manufacturing melt materials of copper, chromium, and at least one readily evaporable component as well as a fusible electrode for using this method is disclosed. More specifically, an arc melting method is used for the manufacture of melt materials based on copper and chromium in which the electrode material melting off a fusible electrode of given resultant composition is collected in a water-cooled permanent mold for the purpose of cooling down without macroscopic separation of copper and chromium. A fusible electrode for use in this method is also provided. This fusible electrode partially consists of a solid alloy of copper with the readily evaporable component.

Method for manufacturing melt materials of copper, chromium, and at

This invention relates to a new use of a fused material of copper and chrome as a contact material for use in vacuum contactors. In addition, the invention relates also to the contact material itself and to the method of its fabrication, as well as for special contact arrangements in the vacuum contactors. The invention shows a whole new, unsuspected range of application for the above fused materials. Up to now, contactors normally used material based on tungsten and copper which were first sintered and then immersed. It has now been experimentally shown that fused materials of copper and chrome, particularly after being reshaped, are very well suited as a contact material for vacuum contactors. Furthermore, in contact pieces of said fused material, methods are provided for additional additives to be precisely inserted by localized alloying, diffusion, or related techniques.

Use of a fusion material of copper and chrome as the contact material

Contact pieces for vacuum switches with axial magnetic field are designed, for example, as pot type contacts with codirectional slotting which contain in each instance a disk-shaped contact body of contact material and have an arrangement for the suppression of eddy currents. Conventional techniques for this purpose typically involves the cutting of radial slots in the contact bodies. In accordance with the invention, each contact piece (10, 110, 210) comprises a plurality of discrete elements (11, 111, 211) which are so arranged on the concrete carrier (2) that their edges (12, 13; 112, 113; 212, 213) form joints (25, 125, 225) and thereby define conductivity jumps for the suppression of the eddy currents. Specifically the discrete segments (111, 211) are produced by reshaping a cylindrical blank (100) of circular cross section into a semi-finished product of circular sectorial cross section.

Contact arrangement for vacuum switches with axial magnetic field, and

Growing community of inventors

Steinbach, Germany

Reiner Mueller