Abstract: A grid ceiling comprising the support grid 10, 12 having first openings 16 therein in at least some of which are mounted first grid elements 24 defining second openings 30 in which second grid elements 40 are mounted. In this way several grid elements of progressively smaller size can be mounted in openings in preceeding grid elements, e.g. to provide a pyramidal structure.

Abstract: A suspension ceiling grid system having grid runners connected at intersections including a through-runner and opposed runner ends connected together and to the through-runner on opposite sides of the through-runner. Each runner end is provided with an end connector which extends through an opening in the web of the through-runner. Each connector is provided with a first-end-in-lock which connects the connector to the through-runner itself and a dual connector-to-connector lock which interconnects the two connectors at the intersection. The first-end-in-lock provides opposed lateral projections which engage the remote side of the web of the through-runner beyond the ends of the opening therein. The connectors may be disassembled from an intersection without the need for tools and without damage to either the connector or the through-runner opening. Further, an intersection can be disassembled and subsequently reassembled in a trapped module condition.

Abstract: A fire rated, demountable partition structure is disclosed which provides H-shaped studs having a core of combustion-resistant insulation material and opposed channel-shaped metal members secured to opposite faces thereof. Spline clips secure one side of the stud to the panel at joints therebetween. Each clip includes a lateral projection extending with a close fit into a kerf in the edge of the panel and a reverse bend providing opposed clip walls which fit along opposite sides of an adjacent flange on the stud. If the partition is exposed to a fire or the like, which tends to cause shrinkage of the panels and opening of the joints, the core of the stud bridges the joint and prevents direct exposure of the metal channel elements of the stud to heat or water through the opened joint. The spline clips are free to expand if the clips are subjected to greater heat than the channel members so that the stud is not caused to bow toward the fire side of the partition.