GUARD BASED ON SPIRAL BARRIER Russian patent published in 2011 - IPC E04H17/02 

FIELD: construction.

SUBSTANCE: guard on the basis of a spiral barrier comprises three spirals of identical diameter made of barbed tape reinforced with a wire core, oriented relative to each other in the form of a triangular prism so that two lower spirals make the base, and the third upper spiral - the prism top, besides, all turns of neighbouring spirals are pairwise connected to each other in points of their contact located on the same straight line along the spiral length. The device comprises a vibration detection device, which includes two cable sensitive elements, the lower and the upper one, at the same time the lower sensitive element is fixed on one of lower spirals along its length and with angular distance φ₁ from 0° to 90° relative to the equator, and the upper sensitive element is fixed on the upper spiral parallel to the lower sensitive element and with the angular distance φ₂ from 0° to 90° relative to the equator of this spiral, at the same time there is a horizontal plane under the spiral equator, which passes through the centre of the spiral turn.

EFFECT: reduced cost of equipment and reduced labour intensiveness of assembly.