A table assembly for a patient transfer device has an upper table with side plates that are differentially extended at the ends, and valve control for pneumatic tubing integrated with refraction of the side plates. During patient delivery only the delivery side plate is raised, to avoid catching linens in the nip formed between upper and lower belts. A slide assembly supporting the table assembly includes a fixed plate, an intermediate plate, and a full-motion plate which extend by means of rack-and-pinion drives. Each plate is symmetrical, and pinions are symmetrically located on opposite sides of the fixed or intermediate plate to allow hyperextension to either the left or right. Improved steerage for the device is provided by two centerline wheels which counter-rotate from a straight position to a turning position and further to a lateral position wherein the wheels are orthogonal to the longitudinal centerline of the device.