摘要 |
The mattress has a matrix spring sheet comprising a set of porous pouches (9-12) adapted to be fixed with each other such that the longitudinal axis of each pouch is perpendicular to a plane of upper and lower sheets. Each pouch has a helical spring (16-19) and a ventilation aperture (20-23) with a diameter greater than the average dimension of pores of the pouch and lesser than the diameter of the spring, where the aperture is circular shaped. |