Interlocking cross tee

Claim 1

In a suspended ceiling grid structure, a cross tee (15) having an inverted T cross section comprising an elongated central web (25) with a bulb (27) at the top and with a pair of oppositely disposed flanges (29) extending outwardly from the bottom of the web (25) and adapted to support ceiling tiles, a connecting tongue (33) extending from an end of the web (25), the tongue (33) being offset from the center of the web by approximately one-half the thickness of the web (25) locking means (37) formed in the tongue (33) for locking said cross tee (15) to a slot (18) provided in a main beam (13) to which the cross tee (15) is connected in the ceiling grid, an interlocking means (47, 51) formed in the tongue (33) for interlocking the cross tee (15) with interlocking means of a similarly constructed but oppositely disposed cross tee (15) when the cross tees (15) are inserted into the slot (18) from opposite directions, and an interlock release means (57) for disengaging the tongues (33) of two similarly constructed but oppositely disposed interlocked cross tees (15) from the interlocked relationship, the improvement comprising shear means (101, 102) on the elongated central web (25) that stops the cross tee (15) from further entering the slot (18) at normal room temperatures, and shears or bends during a fire, comprising (1) a tab portion (102) extending transversely of the tongue (33), and (2) a notch portion (101) adjacent the tab portion (102) on the side away from the end of the tongue (33) whereby, the cross tee (15) is permitted to expand during a fire, wherein the tab portion (102) shears or bends into the notch portion (101).