Closing cap, particularly for a motor vehicle radiator

Abstract

In the housing of a closing cap 2, a valve seat plate 3 is held in place by means of a resilient ring 8 forming at the same time a seal relative to the tank connection to which the closing cap is screwed by its internal thread 1. The valve seat plate 3 supports a sub-pressure valve 4 and an excess-pressure valve 5. Aside from its seal ring 13, the closing member 4 of the sub-pressure valve is made in one piece. The excess-pressure valve 5 comprises a loose valve disc 28 cooperating with a valve seat 27 of the valve seat plate 3. The closing spring 30 is non-rotatably secured to the valve disc 28 and bears by its other open end against a stop 37 so that, by turning the valve disc, the spring pressure is increased or reduced. For this purpose, the valve disc is actuated by a tool introduced through the outlet aperture 21. In another embodiment, a setting member 40 is provided which is rotatable in the outlet aperture and can be displaced in the axial direction of the valve by means of two mating helicoidal surfaces 38, 39.