Fire-rated expansion joint having three degrees of freedom

DETAILED DESCRIPTION The present invention overcomes the problems noted above and provides a greatly improved expansion joint for use between a pair of elongated, adjacent, relatively shiftable structural sections presenting therebetween an expansion void of a given nominal width.
The joint exhibits three degrees of freedom for accommodating virtually all relative movement of the structural members, and is advantageously formed of fire-rated materials such as flexible ceramic-based insulation.
In preferred forms, the expansion joint of the invention includes a pair of elongated supports (typically formed of extruded aluminum) adapted for fixed attachment to a corresponding structural section adjacent an expansion void.
The joint also includes an elongated, flexible bridging member having a width greater than the nominal width of the expansion void, with the bridging member being situated within the void and beneath the supports.
The flexible bridging member is operatively coupled to the supports in a manner for: relative longitudinal shifting movement between the bridging member and one or both of the structural sections in the event of relative longitudinal shifting movement of the latter; compression and stretching of the flexible bridging member upon movement of the structural sections towards and away from each other; and vertical movement of at least a portion of the flexible bridging member in the event of relative vertical movement of the structural sections.
In order to provide the desired coupling between the flexible bridging member and the adjacent section-mounted supports, it is preferred to provide a pair of metallic, shiftably interfitted, elongated, U-shaped elements respectively coupling each side edge of the flexible member and the adjacent supports.
One of these elements is secured to the corresponding support, while the other element is attached to the adjacent edge of the flexible member.
In this fashion, upon longitudinal shifting of the structural sections, a relative sliding movement occurs between the interfitted U-shaped elements of the supports and bridging member edges, so that such movement is accommodated without tearing or undue stress being imposed upon the bridging member