Patient support apparatus deployment mechanisms

A patient support apparatus for supporting a patient, said patient support apparatus comprising:

• a litter comprising a support structure articulable between a seated configuration and a supine configuration, and configured to support the patient in each of said seated and supine configurations, with said support structure comprising:
• a seat section;
• and
• a leg section coupled to said seat section and articulable relative to said seat section around a seat axis between a first angular position in said seated configuration and a second angular position, different from said first angular position, in said supine configuration;
• a steerable wheel assembly coupled to said leg section and configured to engage a floor surface in the seated configuration, with said steerable wheel assembly rotatable relative to said leg section around a steering axis transverse to said seat axis to facilitate turning the litter;
• a wheel system coupled to said leg section and configured to engage the floor surface between said seated and supine configurations, with said wheel system comprising:
• a deployment frame coupled to said leg section and rotatable relative to said leg section around a pivot axis;
• and
• a wheel coupled to said deployment frame and rotatable relative to said deployment frame around a wheel axis parallel to said seat axis to facilitate movement of said litter along the floor surface;
• and
• a wheel deployment mechanism coupled to each of said seat section and said wheel system, with said wheel deployment mechanism configured to rotate said deployment frame around said pivot axis when said leg section articulates between the first and second angular positions for engaging and rotating said wheel around said wheel axis along the floor surface as said support structure articulates between said seated and supine configurations and lifting said steerable wheel assembly off of the floor surface;
• wherein said wheel deployment mechanism comprises a lost motion device configured to rotate said deployment frame around said pivot axis during an active portion of said articulation of said leg section between said first and second angular positions and inhibit rotation of said deployment frame around said pivot axis during an inactive portion of said articulation of said leg section between said first and second angular positions.