rate along said internal passage 3 the axis xx is defined as being the axis of pivoting of the lever 2 on the body 1 of the cock as illustrated in fig2 furthermore the position of the lever 2 at rest serves as a reference for defining the starting axis yy and the angles u03b1 and u03b2 for greater simplicity the axis yy will be chosen as shown in fig2 the axes however in order to define the axis of the lever 2 it would also be possible to choose some other straight line passing through the point p and perpendicular to the pivot axis xx because the most important thing is always to use the same frame of reference in terms of axes fig5 is a diagram in section on a a of fig2 showing the architecture of the gas outlet coupling 19 bearing the outlet orifice 32 this figure also shows a shutter 45 that can move in terms of translation furthermore fig6 is a diagram in section on c c of fig2 providing an understanding of how the lever 2 collaborates with the flow control means particularly the shutter 4 by way of the moving part 5 able to move in its.