far as the reliability of the system is concerned whether this be due to the deterioration or even breakage of its components u s pat no 6 135 763 sets out safety mechanisms whose operation depends on obstructing the opening of the valve unless a specific sequence of movements is carried out on the push button the various solutions claimed in this document have as an objective the obstruction of the action carried out on the valve 39 s opening mechanism the abovementioned embodiment holders the operation on the absence of the application of an active force on the valve 39 s opening mechanism a situation obtained by means of an element incorporated into the push button itself despite the fact that the solution claimed here is economical and simple to execute one inconvenient aspect is the need to execute a two fold operating manoeuvre on the double functional nature of the push button when the latter moves freely on two perpendicular axes this invention 39 s premise is to overcome the inconvenient aspects mentioned by means of mechanisms that block or obstruct its use by children the invention provides a lighter of the type described at the beginning which is characterised in that it has an additional mechanism that acts as a safety element the system is reliable incapable of constant.