Bedsore preventing apparatus

Claim 1

A bedsore preventing apparatus comprising: an air mattress including first, second and third independent groups of air cells defined in said mattress, said air cells in each of said first and second groups respectively interdigitating wherein one end of each air cell meshes with respective air cells in the other group so that air cells from both groups mesh with each other in comb-tooth-like relationship, and said air cells in said third group being disposed to extend continuously in zigzag form between respective said interdigitating first and second group air cells, and being formed to have a height smaller than that of the first and second group air cells and a plurality of small holes made in the top surface of said air cells in said third group, and first and second communication paths respectively including arcuately bent portions generally of a height smaller than said first and second group air cells each of which portions connect the other ends of adjacent two of said interdigitating air cells in each of the first and second groups; first, second and third air supply paths respectively connected at one end to an end of each of said first, second and third air cell groups; first and second valve means provided respectively in each of said first and second air supply paths and actuatable to change over operating state of supplying and discharging air through the supply paths into and out of the first and second air cell groups; means including an electric control circuit connected to said first and second valve means for controlling cyclically alternately said actuation of each of said first and second valve means; and means including an air pump connected to the other ends of said first to third air supply paths for supplying therethrough pressurized air to said first and second groups of air cells for their alternate and sequential expansion and contraction due to said alternate actuation of said first and second valve means, and to said third group of air cells for discharging the air through said small holes, said air supplying means comprising a housing having therein at least first, second and third chambers respectively accommodating each of said air pump, control circuit and first and second valve means, said second chamber forming part of an air intake path from the exterior of said housing to the air pump in said first chamber, while said first and third chambers communicate with each other to form an airblowing path from the pump to the valve means.