Venting plug for stationary batteries, with blast-resistant protection and unlimited, automatic topping-up system, and topping-up assembly employing said plug

摘要

A venting plug for stationary batteries is disclosed, of the type comprising a support body, which may be screwed into an upper opening of a battery element, provided with at least one topping-up hole intended to cause an electrolyte topping-up liquid to precipitate into the battery element, such liquid being introduced into the upper part of said support body, and further comprising a porous element, mounted in the upper part of said support body, intended to act as a filtering barrier for the gases rising up from said battery element towards the outside along said topping-up hole. The support body has inside a topping-up bowl, in communication with two inlet and outlet connections, provided with an upwardly-protruding conduit which open below the bowl into an outlet nozzle, and below the bowl there is provided a hermetic closing element of said nozzle controlled by a float assembly which leads said closing element to obstruct said nozzle when the electrolyte level lies above a preset operational level.