Abstract: A tandem hydraulic valve comprising first and second axially aligned valve spools, a valve guide slidably receiving said valve spools to control, in use, the connection between respective ports of the valve guide, said first and second spools being formed as separate components and being axially interconnected, to move in unison, by an axial connection component, and, the interface of said first and second spools being connected to a predefined, external, hydraulic fluid leakage path.

Abstract: A tandem hydraulic valve comprising first and second axially aligned valve spools, a valve guide slidably receiving said valve spools to control, in use, the connection between respective ports of the valve guide, said first and second spools being formed as separate components and being axially interconnected, to move in unison, by an axial connection component, and, the interface of said first and second spools being connected to a predefined, external, hydraulic fluid leakage path.

Abstract: A failsafe arrangement comprising a first mounting member and a second mounting member which is angularly moveable relative to the first mounting member. The first and second mounting members define first and second surfaces respectively which define therebetween a channel, the first and second surfaces being shaped such that the channel is of non-uniform width. At least one wedge member is disposed within the channel, the or each wedge member being carried by a drive member and being arranged such that, in use, when the drive member and the second mounting member move at substantially the same angular speed, the wedge member does not impair movement of the second mounting member relative to the first mounting member, relative angular movement of the drive member and the second mounting member causing the wedge member to cooperate with the first and second surfaces to apply a braking force so as to impede relative angular movement of the first and second mounting members.