An electrical concertina-type lamp comprises two identical sliding lattices (2, 3) which extend parallel to each other and are made of electrically conductive material, each being connected to one of the poles of a low voltage power source and their respective joints (5, 6) being located ...http://www.google.fr/patents/US5709461?utm_source=gb-gplus-shareBrevet US5709461 - Electrical concertina-type lamp
