Method and apparatus for closing a passageway

• US 3,864,883 A
• Filed: 04/10/1973
• Issued: 02/11/1975
• Est. Priority Date: 04/10/1973
• Status: Expired due to Term

• Current Assignee: Robert M. Mcmarlin
• Original Assignee: Robert M. Mcmarlin
• Inventors: McMarlin, Robert M.
• Primary Examiner(s): Perham, Alfred C.
• Application Number:
  US05/349,767
• Time in Patent Office: 672 Days
• Field of Search: 52/220,221,232,741 174/47,48 220/3,4 138/92
• US Class Current: 52/220.8
• CPC Class Codes: A62C 2/065 having as the main closure device materials, whose characteristics undergo an irreversible change under high temperatures, e.g. intumescent
• CPC Class Codes: E04B 1/947 by closing openings in walls or the like in the case of fire fire-proof doors E06B5/16
• CPC Class Codes: H02G 3/00 Installations of electric cables or lines or protective tubing therefor in or on buildings, equivalent structures or vehicles installations of bus-bars H02G5/00; overhead installations H02G7/00; installations in or on the ground H02G9/00
• CPC Class Codes: H02G 3/185 Floor outlets and access cups

Abstract

A shaped body of intumescent material is positioned in an underfloor access housing in abutting relation with the base of the housing. The body of intumescent material is shaped to extend around the cable inlet opening in the housing base portion, so that a passageway remains for the cables extending from the underlying cable cells to the underfloor access housing outlet opening. When the underlying cable cells and the underside of the access housing are subjected to an elevated temperature, the body of intumescent material foams and expands to substantially fill the access housing and close the opening or passageway between the cable inlet opening and the cable outlet opening to insulate one portion of the access housing from the other and maintain a substantial temperature differential for an extended period of time between the base of the access housing and the closure cap secured to the upper portion of the access housing. In another embodiment a shaped body or bodies of intumescent material are positioned in a duct or cable tray that has cables, tubing and the like therein. When the outer surface of the duct is subjected to elevated temperatures due to a fire the intumescent material foams and expands and insulates the cables and tubing from the outer surface of the duct and thus delays and possibly prevents the thermal destruction of the cables and tubing positioned in the duct. The preferred body of intumescent material contains between 70% - 100% by weight of an intumescing binder, such as sodium silicate or potassium silicate, and between 0 - 30% by weight filler for increasing the viscosity of the foam. Suitable fillers are clay, cellulatable glass and the like. Organic intumescent mixtures may also be employed in the shaped body of intumescent material.

Claims

1. Apparatus for closing a passageway in an underfloor access housing comprising, an underfloor access housing having a base portion with an inlet opening therein and a top portion having an outlet opening therein and a passageway connecting said inlet opening and said outlet opening, a bodY of intumescent material positioned in said housing and having dimensions less than the internal dimensions of said underfloor access housing, said body of intumescent material operable to foam and expand when said underfloor access housing is subjected to elevated temperatures and substantially fill said access housing and close said passageway therein.

2. Apparatus for closing a passageway in an underfloor access housing as set forth in claim 1 in which, said body of intumescent material is positioned on the base portion of the underfloor access housing, said body of intumescent material operable to foam and expand when the base portion of the underfloor access housing is subjected to an elevated temperature and insulate the top portion of said underfloor access housing from the bottom portion of said underfloor access housing.

3. Apparatus for closing a passageway in an underfloor access housing as set forth in claim 1 in which, said body of intumescent material includes between 70% and 100% by weight alkali metal silicate and between 0 and 30% by weight inorganic filler.

4. Apparatus for closing a passageway in an underfloor access housing as set forth in claim 1 in which, said body of intumescent material includes about 90% by weight sodium silicate, about 5% by weight pulverulent cellulatable glass and about 5% by weight pulverulent clay.

5. A method for insulating an underfloor access housing having a base portion with an inlet opening therein and a top portion having an outlet opening therein and a passageway connecting said inlet opening and said outlet opening comprising, positioning a discrete shaped body of intumescent material in said passageway so that an opening remains in said passageway around said body of intumescent material, subjecting said body of intumescent material to an elevated temperature, and thereafter foaming and expanding said body of intumescent material to substantially fill the cross-section of said passageway and close said passageway.

6. A method for insulating an underfloor access housing as set forth in claim 5 which includes, positioning said body of intumescent material in abutting relation with the inner surface of said base portion.