Patent ID: 8552297

Claim:
Insulation spacer for a gas insulated device, comprising: an insulator disc; and an armature extending around an outer periphery of the insulator disc and holding the insulator disc, wherein the armature is ring-shaped defining a ring axis and comprises: two ring base surfaces extending substantially perpendicularly to the ring axis; and a ring inner surface being arranged between the two ring base surfaces and facing the ring axis, wherein the ring inner surface includes at least one protrusion directed radially inwardly towards the ring axis, the at least one protrusion being shaped such that it locks the insulator disc in the armature against movement in both directions parallel to the ring axis, and wherein the ring inner surface including the protrusion is shaped such that for any point of the ring inner surface, there is a path along the ring inner surface from the point to one of the two ring base surfaces, the path being monotonically directed away from the ring axis and being a direct path entirely within a cross-sectional plane containing the ring axis, or an indirect path including a first path portion of predetermined length in a circumferential direction, followed by a second path portion entirely within a cross-sectional plane containing the ring axis, and wherein the ring inner surface is shaped such that the insulator disc is locked in the armature against rotational movement in at least one circumferential direction relative to the ring axis.