Abstract: A mechanical arm includes a base that mount on a selected support. A proximal arm member has a proximal end portion pivotally secured to the base and a distal end portion pivotally secured to a distal arm member. The base has a first fixed gear element disposed thereon, and a second fixed gear element is disposed on the distal arm member. A drive shaft is rotatably disposed on the proximal arm member and includes a first end portion provided with a first drive gear engaging the first fixed gear element and a second drive gear provided with a second drive gear engaging the second fixed gear element such that rotation of the drive shaft acts to pivot the arm members. A drive acts to rotate the drive shaft.

Abstract: An extendable bay for use with a human habitat, such as a slide-out for a recreational vehicle, includes a compartment sized to be received in an opening in the habitat's side wall. The compartment has a bottom, a top, a front panel and a pair of side panels. A cantilever portion extends from the top for a distance beyond the first and second side panels. A lower edge bearing is interposed between the lower edge of the opening and the bottom of the compartment. A cantilever bearing element is interposed between the cantilever portion and the ceiling of the habitat to support the cantilever portion against the ceiling for sliding movement. An automated drive may be provided to extend and retract the bay. Side bearing elements may be provided. Seal strips may also be used to seal the bay relative to the environment.