Foam rubber mattress - has two sets of transverse ventilation passages one above the other separated by layer of foam

摘要

The mattress of foam material, partic. foam rubber, has transverse ventilation passages at intervals. There are two such sets of passages (4) one above the other, and separated by a layer of foam material (2). Each passage in one set can be above or below a ridge (5) between two in the other set. In the central part of the mattress they can be of smaller cross-section than at the head or foot ends. The passages can be of isosceles trapezium section, the longer of their two parallel sides being towards the inside.