Fire-rated grid member with controlled expansion means

Claim 2

A grid member for supporting grid systems and the like comprising: a support member having a web and flanges extending laterally outwardly on opposite sides of said web, said web being formed with at least one generally horizontally extending cut-out section having a portion terminating in close proximity to said flanges and at least a pair of vertically extending slots adjacent opposite sides of said cut-out section in closely spaced relation thereto and terminating at ends in close proximity to said flanges, relatively narrow connecting portions of said web remaining between said slot ends and said flanges and between said cut-out section and said slots for strengthening said web under normal conditions of usage and severable upon expansion for permitting controlled deformation of said flanges and certain portions of said web.

Claim 3

A grid member as defined in claim 1 wherein said cut-out section comprises an elongated slot extending generally parallel to the longitudinal axis of said web and a V-shaped notch extending from said slot intermediate the opposite ends thereof and terminating in an apex in close proximity to said flanges.

Claim 4

A grid member as defined in claim 1 wherein said adjacent slots extend in a direction normal to the longitudinal axis of said web and have V-shaped portions each terminating in an apex in close proximity to said flanges.

Claim 5

A grid member as defined in claim 1 including a bead surmounting said web, said bead having a deformed portion forming a continuation thereof to provide a pair of longitudinally spaced weakened portions for controlling deflection of said bead upon expansion of said support member.

Claim 6

A grid member as defined in claim 4 wherein said web is provided with an opening below said deformed portion of said bead and extending partially thereinto.

Claim 7

A grid member as defined in claim 4 wherein said deformed portion has a double wall thickness of lesser width than the major Portion of said bead.

Claim 8

A grid member as defined in claim 1 wherein said cut-out section comprises an elongated slot extending generally parallel to the longitudinal axis of said web and a V-shaped notch extending from said slot intermediate the opposite ends thereof and terminating in an apex in close proximity to said flanges, said adjacent slots extending in a direction normal to the longitudinal axis of said web and having V-shaped portions terminating in apices in close proximity to said flanges, a bead surmounting said web and having a deformed portion controlling deflection of said bead upon expansion of said support member, and said web being provided with an opening below said deformed portion of said bead for controlling deflection of said web upon expansion.

Claim 9

A grid member as defined in claim 1 together with means on opposite ends of said web for interlocking engagement with adjacent grid members.

Claim 10

A grid member as defined in claim 8 wherein said interlocking means comprises a tab extending laterally outwardly at an angle of approximately 45* from one end of said grid member web and insertable into an adjacent grid member slot.

Claim 11

A grid member as defined in claim 9 wherein said interlocking means comprises a slot in said web adjacent the other end thereof for receiving an adjacent grid member tab.

Claim 12

A grid member as defined in claim 10 including an extension projecting longitudinally outwardly from said other end of said grid member web in a plane laterally offset therefrom and parallel thereto, said extension having an abutment shoulder engageable with an adjacent grid member stop.

Claim 13

A grid member assembly comprising: at least two coaxially aligned grid members each having a web, connecting means on adjacent ends of said webs for splicing said grid members in an abutting end-to-end relation, said connecting means comprising a tongue extending longitudinally outwardly from the abutting end of one web in a plane laterally offset from said one web and parallel thereto, a tab projecting laterally outwardly from the end of said tongue remote from said web at an angle of approximately 45*, said web having stop means projecting outwardly therefrom and disposed longitudinally inwardly from the abutting end thereof, a slot provided in said other web adjacent the abutting end thereof for receiving said tab, an extension projecting longitudinally outwardly from the abutting end of said other web in a plane laterally offset from said other web and parallel thereto, said extension having means adjacent the free end thereof engageable with said stop means in the assembled relation of said grid members.

Claim 14

A grid member assembly comprising: at least two coaxially aligned grid members each having a web, connecting means on adjacent ends of said webs for splicing said grid members in an abutting end-to-end relation, said connecting means comprising a tongue extending longitudinally outwardly from the abutting end of one web in a plane laterally offset from said one web and parallel thereto, a tab projecting laterally outwardly from the end of said tongue remote from said web at an angle of approximately 45*, said web having stop means projecting outwardly therefrom and disposed longitudinally inwardly from the abutting end thereof, a slot provided in said other web adjacent the abutting end thereof for receiving said tab, an extension projecting longitudinally outwardly from the abutting end of said other web in a plane laterally offset from said other web and parallel thereto, said extension having means adjacent the free end thereof engageable with said stop means in the assembled relation of said grid members.

Claim 15

A grid member assembly as defined in claim 12 wherein said stop means comprises a laterally projecting finger struck out of said other web.

Claim 16

A grid member assembly as defined in claim 13 wherein said extension is provided with a pair of axially extending, vertically spaced projections defining an abutment shoulder therebetween engageable with said finger in the assembled relation of said grid members whereby said projections prevent vertical displacement of said grid members relative to each other.