Nålvagn

摘要

A pin carriage (1) in a stretcher device is equipped with six wheels, two of which are horizontal. The carriage is moved in a forwards direction by a first segment (3) attached to a leaf spring on the carriage. This segment engages with a second fixed segment secured to a chain being driven in the transport direction. Free expansion in the transport direction is facilitated by the leaf spring and first segment being able to spring beneath the second segment.