US Patent 7334614 Depth adjustment mechanism

A depth adjustment mechanism, disposed on a router, is enabled using a worm drive that includes a shaft member engaging with a rack member. The shaft member couples with a sleeve disposed on a base of the router. The rack member is coupled with a motor casing of the router. The depth adjustment mechanism enables a user selectable engagement of the shaft member with the rack member. A rotating member, which is coupled with the shaft member, is engaged by a user to displace the shaft member relative to the rack member. The selective engagement of the shaft member with the rack member and rotation enabled by the rotating member enables continuous metered depth adjustment for the router.