RESETTABLE ADVANCEMENT MECHANISM

摘要

An advancement mechanism (530) includes a post (600), an engagement mechanism housing (610) separated into an upper housing (614) section and a lower housing section (616), a first rotational control mechanism (620), a first bias member (630), and a second bias member (640) biasing the post (600) in an unactuated position. The first rotational control mechanism (620) includes a ratchet (622) that is coupled to the post (600) and has ratchet teeth (623). The first rotational control mechanism (620) also has a pawl (624) having pawl teeth (625) configured for mating engagement with the ratchet teeth (623). The first rotational control mechanism (620) and the lower housing section (616) are configured such that the ratchet teeth (623) and the pawl teeth (625) are off-set from each other when the post (600) is in the unactuated position and such that the ratchet teeth (623) and pawl teeth (625) are aligned thereby advancing the ratchet teeth (623) when the post (600) is in an actuated position.