Abstract:
A blanket or curtain of flexible fire retardant material is collapsed and retained within a retaining housing construction positioned adjacent to a curtain wall assembly for firestop sealing thereover. The housing includes a safing angle member secured to the curtain wall assembly and a cover which releases responsive to sensing fire conditions to allow the firestopping blanket to deploy downwardly to extend between curtain wall framing members and be positioned extending across a curtain wall panel for fire protection thereover. Such curtain wall panels are commonly made of glass which tends to fracture during a hot fire. The cover will release the blanket responsive to controlled failure of fusible links which secure the cover to the safing angle member. After deployment the blanket will deflect fire and heat away from the curtain wall panel to prevent the spread of fire to adjacent floors.

Description:
The present utility application hereby formally claims priority of U.S. Provisional Patent application No. 61/573,862 filed Sep. 13, 2011 “A Construction for Firestop Sealing a Building Perimeter Gap Utilizing a Deployable Fire Protective Curtain and Edge of Floor Safing Gap Gasket” filed by the same inventor listed herein, namely, James P Stahl Jr and Julio Lopes and Christopher De Marco, and assigned to the same assignee, namely, Specified Technologies Inc., said referenced provisional application being hereby formally incorporated by reference as an integral part of the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention deals with the field of fireproofing buildings and, particularly, fireproofing between a floor such as a concrete slab and a curtain wall positioned immediately outwardly therefrom. A space is commonly defined between the outer edge of a floor and the curtain wall normally formed by vertical and horizontal framing members with curtain wall panels extending therebetween which are normally transparent and formed of glass. The present invention provides a means for sealing this space or safing gap defined between the outer edge of the floor and the curtain wall for firestopping thereof and preventing the spread of fire vertically between floors. 
     DESCRIPTION OF THE PRIOR ART 
     Many patents have been granted for peripheral building firestopping such as shown in U.S. Pat. No. 466,831 patented Jan. 12, 1892 to P. A. Palmer on a “Means For Protecting Buildings From Fire”; and U.S. Pat. No. 623,385 patented Apr. 18, 1899 to J. A. Sprinkel on a “Fireproof Awning And Curtain”; and U.S. Pat. No. 792,603 patented Jun. 20, 1905 to T. T. Lyman and H. C. Hood, said Lyman assignor to H. W. Johns-Manville Company on a “Fireproof Shutter”; and U.S. Pat. No. 876,171 patented Jan. 7, 1908 to P. W. Graszynski on a “Fireproof Building”; and U.S. Pat. No. 886,968 patented May 5, 1908 to A. M. Fuller on a “Fire Curtain”; and U.S. Pat. No. 2,365,127 patented Dec. 12, 1944 to P. R. Wagner on a “Conflagration Retardative Curtain”; and U.S. Pat. No. 2,736,399 patented Feb. 28, 1956 to H. R. Spencer and assigned to The Erie Enameling Company on a “Wall Structure”; and U.S. Pat. No. 3,766,958 patented Oct. 23, 1973 to N. D. Mitchell on a “Fire Protection Device For Building Structure”; and U.S. Pat. No. 3,968,841 patented Jul. 13, 1976 to T. Z. Harmathy and assigned to Canadian Patents and Development Limited on a “Flame Deflecting Device For Mounting On A Building Exterior”; and U.S. Pat. No. 4,161,204 patented Jul. 17, 1979 to J. C. Kurz on a “Motorized Smoke And Fire Damper”; and U.S. Pat. No. 4,269,901 patented May 26, 1981 to F. N. Chamberlain on a “Device For Protection Against Fire”; and U.S. Pat. No. 4,297,821 patented Nov. 3, 1981 to L. R. Peters on “Building Structures Having Improved Fire Resistant Properties”; and U.S. Pat. No. 4,791,994 patented Dec. 20, 1988 to I Ho on a “Book/Painting/Treasure Equipment Saver”; and U.S. Pat. No. 5,607,758 patented Mar. 4, 1997 to W. C. Schwartz and assigned to BGF Industries, Inc. on a “Smoke Containment Curtain”; and U.S. Pat. No. 5,608,992 patented Mar. 11, 1997 to A. Floyd on a “Fire Resistant House Cover”; and U.S. Pat. No. 5,782,690 patented Jul. 21, 1998 to B. K. Gustafson et al and assigned to International Business Machines Corporation on a “Curtain Fire Damper”; and U.S. Pat. No. 5,809,699 patented Sep. 22, 1998 to M. Joly and assigned to Societe D&#39;Exploitation Du Parc Des Expositions De La Ville De Paris on a “Fire Curtain”; and U.S. Pat. No. 5,860,251 patented Jan. 19, 1999 to J. Gleich on a “Rapidly Deployable Fire-Protection Apparatus”; and U.S. Pat. No. 6,182,407 patented Feb. 6, 2001 to K. A. Turpin et al and assigned to John Manville International, inc. on a “Gypsum Board/Intumescent Material Fire Barrier Wall”; and U.S. Pat. No. 6,367,212 patented Apr. 9, 2002 to N. C. Manning on a “Fire-Retardant Roof Construction”; and U.S. Pat. No. 6,401,487 patented Jun. 11, 2002 to I. K. Kotliar on “Hypoxic Fire Prevention And Fire Suppression Systems With Breathable Fire Extinguishing Compositions For Human Occupied Environments”; and U.S. Pat. No. 6,418,752 patented Jul. 16, 2002 to I. K. Kotliar on “Hypoxic Fire Prevention And Fire Suppression Systems And Breathable Fire Extinguishing Compositions For Human Occupied Environments”; and U.S. Pat. No. 6,918,447 patented Jul. 19, 2005 to E. L. Robinson, Jr. on a “Fire Protection Apparatus And Method”; and U.S. Pat. No. 7,096,629 patented Aug. 29, 2006 to F. Cox on an “Exterior Wall Cladding System For Panels Of Thin Reinforced Natural Stone”; and U.S. Pat. No. 7,482,919 patented Jan. 27, 2009 to L. Franklin on a “Multi-Functional Emergency Egress System”; and United States Publication No. 2002/0059985 published May 23, 2002 to J. Stoebich et al on a “Curtain Arrangement For Preventing Spread Of Smoke”; and United States Publication No. 2004/0159448 published Aug. 19, 2004 to E. L. Robinson, Jr. on a “Fire Protection Apparatus And Method”; and United States Publication No. 2006/0266263 published Nov. 30, 2006 to H. Giesemann on an “Extremely Fireproof Inorganic Foamed Plastic Body”; and United States Publication No. 2007/0204540 published Sep. 6, 2007 to J. P. Stahl, Sr. and J. P. Stahl, Jr. and assigned to Specified Technologies Inc. on a “Means And Method For Fireproof Sealing Between The Peripheral Edge Of Individual Floors Of A Building And The Exterior Wall Structure Thereof”; and United States Publication No. 2007/0275231 published Nov. 29, 2007 to G. Meyer et al and assigned to Scheuten Glasgroep on a “Fire Protection Means And Method For The Production Thereof”; and United States Publication No. 2009/0008039 published Jan. 8, 2009 to A. C. Lambridis and assigned to McKeon Rolling Steel Door Co., Inc. on a “Fire And/Or Smoke Blocking Device”. 
     SUMMARY OF THE INVENTION 
     The present invention provides a firestopping means for use with a conventional curtain wall construction which includes a curtain wall assembly having a plurality of vertical frame members spatially disposed from one another and extending generally vertically. Also the assembly includes a plurality of horizontal framing members spatially disposed from one another and extending generally horizontally between the vertical framing members. A plurality of curtain wall panels are included extending between the vertical frame members and between the horizontal frame members. The firestopping means is designed to be attached to the curtain wall assembly and extend between vertical framing portions along the horizontal framing members at locations above the curtain wall panels extending therebetween. This firestopping means includes a retaining housing positioned adjacent to the curtain wall assembly which includes a safing angle member positioned adjacent to the curtain wall assembly and a cover member detachably secured to the safing angle member and defining therebetween a retaining chamber. A releasable attachment means is also included detachably securing the cover member with respect to the safing angle member. This releasable attachment means is responsive to exposure to fire conditions to disengage the cover member from the safing angle member. A curtain blanket is included having a secured portion thereof attached to the safing angle member and including a free portion thereof. The blanket member can be wrapped such as being rolled or pleated and held in a stored position. The curtain blanket is preferably of a flexible fire resistant material. When oriented in the stored position the curtain blanket can be positioned within the retaining means of the retaining housing. The releasable attachment means will be responsive to exposure to fire conditions to disengage the cover member from attachment with respect to the safing angle member to allow the free portion of the curtain blanket to unfurl and move downwardly to a deployed position extending at least partially across the curtain wall panel located thereadjacent for firestopping thereover. 
     It is an object of the construction of the present invention to prevent fire from spreading between vertically adjacent floors of a building by sealing between the floor and outer wall thereof. 
     It is an object of the construction of the present invention to seal between the outer edge of a concrete slab and a curtain wall assembly positioned immediately thereadjacent and separated therefrom by a safing gap wherein the curtain wall assembly is formed by a plurality of vertical and horizontal framing members with curtain wall panels extending therebetween usually being transparent and usually formed of glass. 
     It is an object of the construction of the present invention to be easy to install and easy to maintain. 
     It is an object of the construction of the present invention to be of minimal initial cost outlay and have minimal maintenance requirements. 
     It is an object of the construction of the present invention to include a flexible sealing gasket formed of a fire retardant cushion such as mineral fiber encapsulated in polyurethane facing which can adapt to various different sizes in the safing gaps of various buildings and various locations within a single building. 
     It is an object of the construction of the present invention to provide a stored fire retardant flexible blanket which can be either rolled or folded within a chamber formed by a safing member and a cover member which automatically deploys responsive to fire conditions. 
     It is an object of the construction of the present invention to provide a construction which utilizes a fusible link preferably of lead, plastic or other similar materials with a low melt point to connect the safing angle member with respect to the cover member which are pre-designed to fail to facilitate downward deployment of the rolled or folded curtain due to gravitational forces exerted upon an activation weight secured thereto. 
     It is an object of the construction of the present invention to provide a deployable curtain blanket member which is usable for fire protection of floor to ceiling glass in buildings. 
     It is an object of the construction of the present invention to be usable with a separate membrane which can be factory applied as a means for forming a secondary seal for water or water vapor as may be deemed necessary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While the invention is particularly pointed out and distinctly described herein, a preferred embodiment is set forth in the following detailed description which may be best understood when read in connection with the accompanying drawings, in which: 
         FIG. 1  is a perspective view showing the curtain wall assembly of the present invention with the curtain blanket member fully deployed extending over at least a portion of the curtain wall as viewed from the building interior; 
         FIG. 2  is a perspective view of the embodiment shown in  FIG. 1  including the positioning of the concrete slab building floor with a safing gap insulation member in place; 
         FIG. 3  is a perspective view of the embodiment shown in  FIG. 1  with the curtain blanket member removed for clarity showing the positioning of the attachment brackets attached in this embodiment with respect to the curtain wall framing members; 
         FIG. 4  is a perspective view of the construction of the present invention shown from the outside of the building illustrating the curtain blanket member deployed and extending over at least a portion of the curtain wall panel; 
         FIG. 5  is a perspective view of the illustration shown in  FIG. 1  with the curtain blanket member removed for clarity and with a firestopping pillow positioned between the outer edge of the concrete floor and the safing angle member for firestop sealing therebetween; 
         FIG. 6  is a perspective view of the construction of the present invention showing a rolled curtain blanket member retained within the retaining chamber defined between the safing angle member and the cover member; 
         FIG. 7  is a perspective illustration showing the entire safing angle member with a cover member secured thereto and the fusible links maintaining securement therebetween and showing a curtain blanket member therewithin which is rolled; 
         FIG. 8  is a perspective illustration of the embodiment shown in  FIG. 7  illustrating an expanded view of the end thereof to more fully show the rolled configuration of the curtain with the activation weight positioned therewithin; 
         FIG. 9  is a side plan view of the curtain blanket member which is rolled and shown contained within the retaining chamber defined between the safing angle member and the cover member; 
         FIG. 10  is an illustration showing the embodiment of  FIG. 9  secured in place to a curtain wall with the safing gap insulation member attached thereto and positioned within the safing gap defined between the curtain wall and the outer edge of the building floor with the curtain blanket member in the retained non-deployed state; 
         FIG. 11  is an illustration of the embodiment shown in  FIG. 10  after the curtain blanket member has been fully deployed downwardly therefrom; 
         FIG. 12  is an illustration of the embodiment shown in  FIG. 11  prior to deployment thereof; 
         FIG. 13  is a cross-sectional view of an illustration of an alternative embodiment of the apparatus of the present invention similar to  FIG. 10  but utilizing the folded configuration for the curtain blanket member; 
         FIG. 14  is a side plan view of the embodiment shown in  FIG. 13  showing a folded curtain blanket member; and 
         FIG. 15  is an illustration identical to  FIG. 7  except for the inclusion of a folded curtain rather than a rolled curtain configuration. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention provides a construction for firestop sealing across the span on the inside of curtain wall panels  30  which are position outside of the outer edge  34  of interior building floors  32  which are normally of concrete and separate from the curtain wall assembly  24  by a gap or space commonly referenced as the safing gap  36 . In the conventional construction of buildings having curtain walls  24  the outer edges  34  of the individual floors  32  thereof need to include some type of a firestopping means for firestop sealing of the safing gap  36  positioned therebetween. Furthermore, such construction designs need fireproofing to prevent fire from spreading from floor to adjacent upper floor through fractured curtain walls panel  24  which can easily break responsive to fire since they are often of transparent materials such as glass. This spread of fire and heat and smoke to upper floor from lower floors can travel through the safing gap  36  and as such a safing gap insulation member  38  is preferably placed therewithin. 
     Such curtain wall constructions  24  commonly include vertical framing members  26  and horizontal framing members  28  with curtain wall panels  30  extending therebetween. It is important to protect against fire spreading to upper floors through broken curtain wall panels and upwardly along the outside surface of a building. Such curtain wall panels  30  are usually transparent and often of glass and can easily fracture responsive to the heat and flame conditions of a fire. The destruction of the curtain wall panels  30  during a fire can allow the fire to travel upwardly along the outside of the building to the next floor and fracture the curtain wall panel  30  on the next floor and thereby allow the fire to leap from a given floor to an immediately floor thereabove by traveling up the exterior of the building until it traveled many floors upwardly quite quickly. The present invention provides a means for inhibiting this spread of fire upwardly between adjacent vertical floors along the building exterior by inhibiting the fire flames from traveling from the building interior to the building exterior through fractured curtain wall panels  30 . 
     With the construction of the present invention a safing angle member  10  preferably of steel material and a cover member  12  are detachably secured with respect to one another solely by a plurality of releasable attachment means  22  such as fusible links  22 . Such fusible links could comprise lead or thermoplastic attachment means with a relatively low melting point to facilitate speedy release of attachment means  22  responsive to being exposed to fire and or heat. Disengagement of the releasable attachment means  22  will release the cover member  12  from engagement with the safing angle member  10 . Since the safing angle member  10  is preferably secured with respect to the building the cover member  12  normally falls away therefrom downwardly. The cover member is normally formed of an aluminum or a non-metallic material and the safing angle member  10  is preferably of steel. These two members when secured together by the releasable attachment means  22  define therewithin retaining chamber means  13 . This retaining chamber means  13  holds a curtain blanket member  14  therein. The curtain blanket member  14  is preferably of a flexible fire retardant material such as a fire retardant ceramic fiber blanket. It is totally retained within the retaining chamber means  13  defined between the safing angle member  10  and the cover member  12  within the retaining chamber means  13  defined therebetween in the steady state condition prior to exposure thereof to fire or heat. The blanket  14  can be retained in the stored or undeployed stored position  56  in a rolled manner such as shown by rolled curtain  16  in  FIG. 9  or it can be folded with pleats  17  as shown by folded curtain  18  in  FIG. 13 . 
     When the releasable attachment means or fusible link means  22  disengages and the cover member  12  falls away from the safing angle member  10  the curtain blanket member  14  will be free to fall downwardly and unfurl or unfold. The curtain blanket  14  preferably includes a secured portion  52  which is attached to the safing angle member  10  and a free portion  54  which can freely unfurl or unfold as it moves downwardly due to gravitation force after full disengagement of the cover member  12  from safing angle member  10 . An activation weight  20  can be secured with respect to the free portion  54  of the rolled curtain  16  or the folded curtain  18  preferably along the lowermost edge of the free portion  54  such that when it falls downwardly from the stored or secured position  56  toward the fully deployed position  40  gravitational forces acting upon the curtains  16  and  18  and, most particularly, upon the activation weight  20  will cause the curtain to unfold or unroll downwardly to the fully deployed position as shown in  FIG. 1 . 
     In this position the vertical length of the deployed curtain blanket  14  will cover a significant portion of the curtain wall panel  30  to which it is adjacent. In some applications it may be necessary to cover the entire curtain wall panel  30  such that the curtain blanket member  14  will extend completely downwardly over the entire expanse of the curtain wall panel  30  thereadjacent and, preferably, to the upper edge of the floor  32  located therebelow. However, it has been found that the prevention of the spreading of fire upwardly along the outside edge of the building can be achieved in some building constructions by the deployment of a curtain blanket member  14  which extends downwardly to a limited distance of perhaps two, three or four feet. Use of such s curtain blanket member  14  positioned downwardly across a significant part of the upper portion of the curtain wall panel  30  will form a sufficient barrier to the movement of flame even though it terminates at a position short of the lowermost edge curtain panel edge. Effective prevention of fire from passing through a fractured wall panel area can thus be achieve even though the curtain blanket only extends downward over the upper portion of a wall panel area. As long as the curtain blanket extends downwardly from the uppermost portion of the curtain wall panel adjacent to the edge of the floor thereabove, prevention of the spreading of fire outwardly through the fractured curtain wall panel can be achieved. Thus, it is within the contemplation of the present invention that the curtain blanket member  14  when fully deployed as shown in  FIG. 1  can extend down a limited distance along the curtain wall panel  30  or, if deemed necessary can extend downwardly to an extent to cover the entire curtain wall panel  30  depending upon the requirements of the particular application. The apparatus of the present invention is preferably attached to the vertical framing members  26  or the horizontal framing members  28  by way of attachment brackets  19 . These attachment brackets  19  are best shown in  FIG. 3 . The brackets  19  could be attached to either the vertical frame members  26  or the horizontal frame members  28  or can be attached to both for firm securement of the safing angle member  10  with respect to the curtain wall  24 . The brackets could also be attached to the adjacent upper floor or the safing insulation therearound. 
     To form an effective complete firestopping means for preventing the spread of fire vertically between floors, it is preferable that a safing gap insulation member  38  be positioned within the safing gap  36 . For this purpose a fire retardant gasket or pillow can be attached, preferably to the downwardly extending leg of the safing angle member  10  prior to installation such that when it is placed in position attached to the curtain wall  24  the safing gap insulation pillow  38  will already be positioned in abutment with the outer floor edge  34  of adjacent floor  32  thereby effectively sealing the safing gap  36  as best shown in  FIG. 10  with a minimum of labor time. 
     As such, the present invention provides a drop down blanket  14  preferably of flexible firestopping material such that it will prevent the spread of fire floor to floor outside of the edge of a conventional floor or slab through fractured curtain wall panels  30  which are often made of glass. The curtain blanket member  14  will preferably be formed of a thin fire retardant ceramic fiber material. Such materials need only be flexible and fire retardant and many cloth-like or other woven materials can be used while maintaining the effective construction shown to be advantageous in this construction whether they are folded or rolled. 
     The curtain blanket member  14  is attached at multiple locations to the safing angle member  10  which is preferably of steel. The retained and undeployed curtain blanket member  14  is secured in place within the retaining chamber  13  by the cover member  12  which is attached to the safing angle member  10  such as to define the retaining chamber  13  therewithin only by the fusible links  22 . These fusible links  22  can be of lead or plastic or other similar material having a very low melting point such that when fire conditions exist the cover member  12  will fall away and allow deployment of the curtain blanket member  14 . 
     It should be appreciated that the safing angle member  10  can be secured to the curtain wall  24  with respect to the vertical frame members  26  or with to the horizontal frame members  28  or both. 
     The safing gap insulation member  38  preferably is a flexibly resilient compressible fire retardant material such as a mineral fiber cushion or pillow. Such a mineral fiber cushion is normally encapsulated with polyethylene facing and, preferably, is affixed in any conventional means with respect to the downward protruding leg of the safing angle member  10 . In this manner the construction of the safing angle member  10  and cover member  12  with the curtain blanket  14  retained therewithin and the safing gap insulation member  38  attached to the outer surface of the safing angle member  10  can be attached as a single unitary construction with respect to the curtain wall  24  prior to installation thereof which greatly facilitates such installation and minimizes labor costs. It should be appreciated that an aesthetic cover may extend over the operating construction of this invention including extending over the safing angle member  10  and the cover member  12  to conceal the curtain during normal building operations. 
     It should be appreciated that when the construction of the present invention including the safing angle member  10  and the cover member  12  and the retained blanket  14  with the safing gap insulation member  38  secured to the safing angle member can be installed in a single step prior to installation of the curtain wall  24  and for this reason the flexibility of the safing gap insulation member  38  becomes very important. This construction preferably will comprise a flexible mineral fiber cushion  38  which will then act as a gasket as it compresses against the outer floor edge  34  of the building interior floor slab  32  which seals off the vertical path between adjacent floors between the curtain wall  24  and the building interior floor  32 , which is preferably a concrete slab. In such installations it is common, however, to include a separate membrane which may be factory applied or can be applied at the job site which starts from the upper surface of the slab adjacent to the safing gap and extends across the upper surface of the safing gap  36  to the curtain wall  24 . This separate membrane preferably provides a secondary seal for water or water vapor. 
     The secured portion  52  of curtain blanket member  14  which is preferably formed of a ceramic fiber material is preferably secured with respect to the safing angle member  10  at multiple locations to maintain connection therebetween before and after deployment. Similarly the activation weight  20  will be secured with respect to the free portion  54  of the blanket member  14  at multiple locations to maintain connection therebetween before after deployment. 
     It should be appreciated that the construction of the safing angle member  10  and the cover member  12  which define the retaining chamber  13  with the undeployed blanket member  14  contained therewithin can be usable with various different configurations of safing gap insulation members  38 . For example, a field directed system of mineral wool with firestop caulking or spray could be installed into the gap between the outer edge  34  of the floor slab  32  and the downwardly projecting leg of the safing angle member  10 . Furthermore the safing angle member  10  could be secured in certain applications instead with respect to the outer edge  34  of the floor slab  32  and extend into the curtain wall cavity to provide protection in a similar manner. With this construction it may or may not be necessary to provide additional safing gap insulation  38  for effectively sealing of the safing gap  36  completely for assuring full firestop sealing between the curtain wall  24  and the outer floor edge  34 . 
     While particular embodiments of this invention have been shown in the drawings and described above, it will be apparent that many changes may be made in the form, arrangement and positioning of the various elements of the combination. In consideration thereof, it should be understood that preferred embodiments of this invention disclosed herein are intended to be illustrative only and not intended to limit the scope of the invention.