Patent ID: 7146662
Filing Date: 2006-12-12
Classification: A47B,A47C

Abstract:
1. A self-leveling bed support frame, comprising: a) a lower frame, having a planar, rectilinear shape with four corners; b) a pneumatic actuator disposed at each corner of the lower frame, each of said pneumatic actuators having extension means, said extension means having an upper end, in which the axis of extension of all four extension means are parallel; c) a rectilinear, planar upper frame, with four corners, wherein the upper ends of each extension means of the pneumatic actuators engages with one of the four corners of the upper frame; d) a seat back assembly comprising a rectilinear frame, wherein said seat back assembly articulates with the upper frame, wherein the seat back assembly articulates about an axis, said axis disposed parallel and proximate to one end of said seat back assembly and parallel and proximate to the minor centerline of the upper frame; e) lifting means comprising a linear actuator for displacing one end of the seat back assembly relative to an end of the upper frame, wherein the lifting means comprises one or more scissors assemblies, each scissors assembly comprising a pair of elongated members, each member having an upper end and a lower end, the two elongated members of each pair articulating at their longitudinal centers, wherein the linear actuator engages with a lower end of one elongated member in each lifting assembly, and wherein an upper end of another elongated member engages with the seat back assembly; f) a plurality of level sensors disposed along two control axes, said sensors operating when either of said control axes is displaced from level, and g) pneumatic valves, wherein said pneumatic valves are in pneumatic communication with one or more pneumatic actuators and in communication with said level sensors.