Plug and socket with alternative rotary positions - has nine out of ten contacts in groups of three around two concentric circles

摘要

The contact arrangement for a plug and socket is used for a system in which the plug can be rotated into alternative connecting positions. This ensuresthat the contacts are kept clean. Seven contacts are arranged on an outer pitch circle, and three contacts on an inner pitch circle. Nine of the contacts are arranged in groups of three forming three triangles. The distance between those contacts on the outer circle and those on the inner circle for each triangle, is equal to the distance between those contacts on the inner circle which form an equilateral triangle. This ensures sufficient spacing between pins for electrical safety, whilst leaving room for the remaining contact on the outer circles.