Patient transport apparatus base with trolley for removable litter

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

• a base having a head end and a foot end, the base including:
• a base frame arranged for movement about a floor surface, and
• an intermediate frame operatively coupled to the base frame, the intermediate frame including a trolley configured to translate between a plurality of trolley positions including a trolley forward position where the trolley is arranged at the head end of the base and a trolley docking position where the trolley is arranged at the foot end of the base, the trolley defining a lower pin stop and an upper pin stop spaced above the lower pin stop;
• and
• a litter for supporting the patient, the litter configured to be docked to and undocked from the trolley, the litter including:
• a patient support surface for supporting the patient,
• a litter lift device configured to adjustably support the litter relative to the floor surface between a plurality of positions including a litter lift chair position and a litter lift dock position, wherein at least a portion of the patient support surface is closer to the floor surface in the litter lift dock position than in the litter lift chair position,
• a lower pin extending from the litter, and
• an upper pin extending from the litter and spaced above the lower pin;
• wherein at least one of the upper pin and the lower pin are configured to be received by the trolley when the litter lift device is in the litter lift chair position, and, when the at least one of the upper pin and the lower pin have been received by the trolley, the litter lift device is configured to actuate from the litter lift chair position to the litter lift dock position to lower the litter such that the lower pin abuts the lower pin stop and the upper pin abuts the upper pin stop to dock the litter to the trolley.