Telescopic isolating switch

In a telescopic isolating switch having a base conductor tube (10) connected to an electrical connection point (5), intermediate conductor tubes (11, 12) and an end conductor tube (13) bearing an electrical contact, means for nestably mounting said tubes in one another for retracting said tubes as the isolating switch moves to a retracted position, the improvement comprising:

• deployment and retraction means of the isolating switch comprising a set of telescopic members including said base conductor tube (10), intermediate tubular members (11', 12') in equal numbers to the conductor tubes, and an end tubular member (13');
• mechanical displacement means for displacing the intermediate member (11') which is adjacent to the base member (10);
• and
• mechanical link means associated with each intermediate tubular member (11', 12') for linking the movements of the corresponding intermediate tubular member relative to the tubular members adjacent thereto, and comprising, in each intermediate tubular member (11', 12'), two pulley wheels (110, 111 or 120, 121), each fixed for rotation about its axis in the proximity of a respective end of the associated intermediate tubular member, together with an endless loop passing over the two pulley wheels (110, 111 or 120, 121) and means for mechanically attaching said endless loop at two diametrically opposite points (116, 107 or 126, 127) to the ends of the tubular members that are adjacent to the associated tubular member.