Portable spiral staircase
AssigneeModular Industries Ltd.
InventorA. Peter Carmel
Life of this patent
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Abstract
A self-supporting helical staircase having an interconnected series of radial steps adapted to be swingably opened for providing vertically spaced horizontal support surfaces. The steps are angularly displaceable about a pintel post in progressive increments and are resiliently coupled for snap-lock engagement when in the fully extended position. A vertically extendible elongate handle is housed within the pintel post and can be locked at selected heights by a pressure clamp arrangement mounted at the upper end of the pintel post. The elongate handle can be folded about an articulated joint to a substantially horizontal position when in non-use. A sleeve member is slidable along the handle and can be positioned over the joint to provide vertical rigidity when the handle is to be used.
Claims11
A portable spiral staircase in the form of a free-standing structure comprising a plurality of step means for providing horizontal support surfaces, said step means being hingedly mounted to a pintel post for swingable movement and angularly displaceable about a common vertical axis from a nested non-operative mode into an open operative mode, coupling means for releasably securing the steps in the open mode, said pintel post having means adapted for supporting elongate handle means.
Dependencies are inferred from the claim text.