Patent ID: 7421748

Claim:
A supported frame that is operable at and between a high and low position, said supported frame comprising: a frame; a first articulating structure having; a first caster support; a first rigid support having a first rigid support first end and a first rigid support second end, said first rigid support first end being rotatably connected to said frame and said first rigid support second end being rotatably connected to said first caster support; and a first serpentine support having a first serpentine support first end and a first serpentine support second end, said first serpentine support first end being rotatably connected to said frame and said first serpentine support second end being rotatably connected to said first caster support; and a second articulating structure having; a second caster support; a second rigid support having a second rigid support first end and a second rigid support second end, said second rigid support first end being rotatably connected to said frame and said second rigid support second end being rotatably connected to said second caster support; and a second serpentine support having a second serpentine support first end and a second serpentine support second end, said second serpentine support first end being rotatably connected to said frame and said second serpentine support second end being rotatably connected to said second caster support, wherein as said first rigid support second end rotates away from said frame, said first serpentine support second end extends away from said first serpentine support first end, and said first rigid support second end and said first serpentine support second end cooperate to maintain a selected orientation of said first caster support at both the high position and the low position of the supported frame, and wherein as said second rigid support second end rotates away from said frame, said second serpentine support second end extends away from said second serpentine support first end, and said second rigid support second end and said second serpentine support second end cooperate to maintain a selected orientation of said second caster support at both the high position and the low position of the supported frame.