Fire expansion joint for ceiling runner

Claim 1

An expansion runner for a ceiling system comprising: (a) a vertical web member with upper and lower ends; (b) said vertical web member having an enlarged bulb at its upper end and a horizontal flange extending from both sides of its lower end; (c) said runner having an upper elongated opening adjacent the upper end of the web and, said runner having a lower elongated opening positioned in the vertical web intermediate the upper and lower ends of the vertical web; (d) the upper and lower openings having a length taken along the length of the runner selected to accommodate anticiapted axial expansion of the runner upon exposure to a fire; (e) the improvement comprising: (1) said upper elongated opening extends from the upper end of the web into the enlarged bulb, the upper elongated opening having upper and lower edges, said upper edge having only one triangular notch therein with the notch positioned at the midpoint of the upper edge and extending to almost the top of the enlarged bulb, at each end of the upper edge a straight line cut with abutting edges extends from the upper opening toward and to almost the top of the enlarged bulb, and (2) said lower elongated opening having upper and lower margins, said upper margin being spaced from the lower edge of the upper elongated opening, said lower margin having only one triangular notch therein with the notch positioned at the midpoint of the lower margin and extending to adjacent the horizontal flange, at each end of the lower margin a straight line cut with abutting edges extends from the lower opening toward and to almost the top of the horizontal flange.