Staircase cabinet

DETAILED DESCRIPTION To achieve the foregoing objects and advantages, and in accordance with the purposes of the invention as embodied and broadly described herein, the staircase cabinet of the present invention comprises a plurality of treads, each having an outer edge, an inner edge and a back surface.
Outer stringer means are provided both for defining opposed walls of the cabinet and supporting the outer edges of each tread.
An inner stringer supports the inner edges of each tread.
Fastening means attach the treads to the inner stringer and the outer stringer means in alternating arrangement on respective opposite sides of the inner stringer to define an alternating staircase for use between a lower level and an upper level.
The back surface of the treads and the outer stringer means define a cabinet space.
It is preferred that the outer stringer means include a pair of opposed planar members, the inner stringer being disposed at a predetermined angle of inclination between the planar members.
It is also preferred that the planar members and the inner stringer each include mortise means defining a channel for supporting the tread, at least one of the treads include tenon means for insertion into the channel, and the fastening means include bolt means for securing the tenon means in the channel.
In addition, the bolt means may include a bolt having a rectangular shaped head, and the mortise may include keyway means in each of the planar members and the inner stringer for rotatably receiving the rectangular shaped head therein.
It is preferred that the outer walls of the cabinet be substantially parallel to each other and the cabinet may include a shelf removable fixed between the planar members for strengthening the cabinet, and the cabinet may include a tensile rail between the planar members for increasing the rigidity of the cabinet.
A plurality of risers are preferably provided between the inner stringer and the planar members.
The risers are positioned at least between adjacent pairs of treads on the same side of the inner stringer and means are provided for attaching the risers between the inner stringer and the planar members in alternating arrangement on respective opposite sides of the inner stringer