US Patent 7373761 Self-adjusting intumescent firestopping apparatus

A self-adjusting firestopping apparatus for holding of intumescent material within poke-through openings in construction barriers usually being floors but also possibly being walls or ceilings wherein cables or other penetrating members extend therethrough. The self-adjusting apparatus includes a sleeve with the intumescent material centrally located therein and preferably two plates extending along the sleeve and movably attached thereto by a flexibly resilient support device such as a coil spring or flat spring. This plate provides a movable false panel which is adapted to expand responsive to the placement of increasing numbers of penetrating members extending therethrough to increase the capacity of the intumescent firestopping device.