High-voltage switch

Abstract

Two series-connected main switching contacts (1a, 1b) mounted on a housing (7) are actuated, in conjunction with an auxiliary switching unit (4) for switching a closing or starting resistance (3), by a drive (5) via a switching drive mechanism (6). To obviate the need for a second auxiliary switching unit and to achieve other cost reductions, the closing resistance (3) and the auxiliary switching unit (4) are connected in a parallel circuit and in series between the main switching contacts (1a, 1b). The foregoing components are accommodated in the housing (7). During a switching-on process, the auxiliary switching unit (4) closes after the main switching contacts close (1a, 1b) and the closing resistance (3) is bypassed. During the switching-off process, the auxiliary switching unit opens after the main switching contacts (1a, 1b). A hollow cylinder (21) which carries a moving contact member (9) of the auxiliary switching unit (4), is displaceable to a limited extent with respect to a guide rod (16) of the switching drive mechanism. The hollow cylinder is pushed by a plunger (17) on the guide rod (16) and by a ramming piston (18) into an on position at which the moving contact member (9) locks into a fixed contact member (10). During the switching-off process, the locking mechanism, which can normally withstand a counter force exerted by a tension spring (27), is released by the plunger (17). In another embodiment, the moving contact member of the auxiliary switching unit is constructed as a blade contact which is pivoted on the metal housing.

Dependencies are inferred from the claim text.