A bed 14 has a base frame 32, an elevatable frame 34 and a telescopable column 36 having a base segment 36a connected to the base frame 32 and a terminal segment 36e connected to the elevatable frame 34. Each column circumscribes a lift chain assembly 100 which includes a magazine 102 and a lift chain 160 with a terminal link 240. The magazine 102 is connected to either the base frame 32 or the elevatable frame 34 and the terminal link 240 is connected to the other of the base frame 32 and the elevatable frame 34. The magazine 102 comprises left and right magazine covers 104, 106 each having an outer face and an inner face 112, 114 with grooves 120. The lift chain 160 has left and right rollers 238 that project into the grooves. The lift chain assembly 100 also includes a gear train 320 extending from a gear train drive shaft 334 to a gear train output shaft 338 and a motor 278 having an output shaft 314 connected to the gear train drive shaft 334.
