Auto leveling low profile patient support apparatus

A patient support apparatus comprising:

• a tiltable patient support surface having a head end and a foot end, and being articulated to allow for independently raising and lowering the head end and the foot end relative to the remainder of the patient support surface;
• a base frame having structural components including first and second end members;
• a repositioning mechanism extending between the patient support surface and the base frame, and operable to vertically reposition and angularly reposition the patient support surface relative to the base frame;
• wherein the repositioning mechanism includes first and second frame members and oppositely oriented first and second lift actuators which pivot the first and second frame members between a first position in which the patient support surface is raised relative to the base frame, and a second position in which the patient support surface is lowered relative to the base frame, and wherein when the first and second frame members are pivoted equally the patient support surface is vertically repositioned and when the first and second frame member are pivoted unequally the patient support surface is angularly repositioned;
• a tilt control system operable to prevent raising or lowering the head end and the foot end beyond a minimum extent and a maximum extent and inhibiting potentially damaging contact between the repositioning mechanism and the first and second end members, and including an input device operable to allow for specifying the minimum extent and the maximum extent, and
• wherein the minimum extent is variable based on a tilt of the support surface, and the maximum extent is variable based on a tilt of the support surface.

A patient support apparatus comprising:

• a tiltable patient support surface having a head end and a foot end, and being articulated to allow for independently raising and lowering the head end and the foot end relative to the remainder of the patient support surface;
• a base frame having structural components including first and second end members;
• a repositioning mechanism extending between the patient support surface and the base frame, and operable to vertically reposition and angularly reposition the patient support surface relative to the base frame;
• wherein the repositioning mechanism includes first and second frame members and oppositely oriented first and second lift actuators which pivot the first and second frame members between a first position in which the patient support surface is raised relative to the base frame, and a second position in which the patient support surface is lowered relative to the base frame, and wherein when the first and second frame members are pivoted equally the patient support surface is vertically repositioned and when the first and second frame member are pivoted unequally the patient support surface is angularly repositioned;
• a tilt control system operable to prevent raising or lowering the head end and the foot end beyond a minimum extent and a maximum extent and inhibiting potentially damaging contact between the repositioning mechanism and the first and second end members, and including an input device operable to allow for specifying the minimum extent and the maximum extent, and
• one or more sensors operable to automatically detect and inhibit an attempt to vertically reposition the patient support surface when the patient support surface is in a particular angular position, and to automatically detect and inhibit an attempt to angularly reposition the patient support surface when the patient surface is in a particular vertical position.