Patent ID: 8794266

Claim:
A valve assembly for a patient support mattress having a plurality of bladders, said valve assembly operable to selectively discharge fluid from the bladders of the patient support mattress and comprising: a plurality of valves, said valves being operatively connected with the bladders of the patient support system and selectively moveable between a closed position and an open position; a cam that selectively actuates said valves, said cam being moveable between a position in which fluid is sealed from discharge by said valves and a position in which said valves are in said open position; and an electrical actuator connected to said cam and a manual actuator connected to said cam, both said electrical actuator and said manual actuator being separately operable to move said cam to open said valves; said cam including a plurality of cam surfaces with movement of said cam causing said cam surfaces to move relative to said valves to open said valves with said cam surfaces including an initial portion that commences opening of said valves, and with the spacing of said initial portion of one said cam surface relative to an associated said valve being different from the spacing of said initial portion of another said cam surface relative to its associated said valve whereby commencement of opening of all said valves does not occur simultaneously during movement of said cam.