IMPROVEMENTS TO SECURITY ARRANGEMENT METHODS AND COMPUTER SOFTWARE

摘要

A security arrangement of a fluid operated machine comprises a fluid inlet for channelling fluid into a chamber; said chamber having two outlets; a first outlet being provided to channel fluid to an operative component of said fluid operated machine; a second outlet being provided to channel fluid to a non-operative destination; wherein the arrangement incorporates a piston which is displaceable relative to said outlets between a first position where said first outlet is fully open whilst said second outlet is closed and a second position where said second outlet is open whilst said first outlet is fully closed; said piston and outlets being configured so that during displacement between said first and second position the extent of aperture of one outlet is proportional to the extent of closure of the other outlet.