An electronic equipment drawer 20 is aligned with an electrical connector in a tunnel in the horizontal and vertical directions with alignment pins and holes. A screw drive 34 and cam 36 mounted on the drawer engages a tunnel wall and controls insertion into the tunnel to provide proper electrical contact...http://www.google.es/patents/US5496181?utm_source=gb-gplus-sharePatente US5496181 - Serviceable data terminal structure
