Patent ID: 9611738
Date: 2017-04-04
CPC Classifications: E21D,E21F

Claim:
1. A longitudinally yieldable support, comprising: an elongate outer shell in the form of a column and defining a first pair of apertures located along a wall of the elongate outer shell, the first pair of apertures each positioned on opposite sides of the elongate outer shell from one another; a first air ventilation tube having first and second ends attached to the wall and extending transversely through the elongate outer shell at a location of and between the first pair of apertures, an outer tube diameter of the first air ventilation tube being approximately equal to an aperture diameter of the first pair of apertures; and a solid compressible filler material disposed within the elongate outer shell and encapsulating the first air ventilation tube within the elongate outer shell; the first air ventilation tube having a wall thickness sufficient to prevent the first air ventilation tube from collapsing as the elongate outer shell and solid compressible filler material yield around the first air ventilation tube such that the first air ventilation tube does not collapse or yield when the elongate outer shell and solid compressible filler material yield to allow a flow of air through the first air ventilation tube as the elongate outer shell and solid compressible filler material yield.