Stock material or miscellaneous articles – Web or sheet containing structurally defined element or... – Composite having voids in a component
Reexamination Certificate
1999-02-22
2002-07-09
Juska, Cheryl A. (Department: 1771)
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
Composite having voids in a component
C428S306600, C428S307300, C428S343000, C442S001000, C442S009000, C442S019000, C442S020000, C442S022000, C442S030000, C442S045000, C442S055000, C442S056000, C442S063000, C442S076000, C442S221000, C442S226000, C442S370000, C442S374000
Reexamination Certificate
active
06416854
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to monolithic in situ field-applied roofing surface membranes. Preferably, the surface membrane is a fabric or fiberglass imbedded low rise polyurethane adhesive covered by a waterproof and ultraviolet resistant coating, such as a silicone coating.
The present invention also relates to a new and useful method and industrial robotic device for applying coatings or other spray coated layers, in uniform thicknesses and at appropriate angles of pitch, in field applications, such as roofing applications or pavement applications.
BACKGROUND OF THE INVENTION
In the roofing applications, flat roofs are often made of polyurethane foam layers, which may be covered by various coatings, such as elastomeric coatings, such as silicone. It is difficult to maintain a uniform thickness when applying a foam or elastomeric material, which by its nature rises when applied to achieve a thickness above a roof base.
Furthermore, the faster that a foam applicator passes over a surface, the less volume of foam is applied, resulting in less of a thickness of the applied foam. To achieve thicker foam layers, a spray applicator is slowed down in velocity as it passes over the roof bases, so that more foam material is discharged per square unit of space of roof base being passed over by the spray applicator.
Various attempts have been made to apply foam uniformly, such as from an applicator moving at a uniform speed along a carriage track. However, at the end of each pass of an applicator over a portion of a roof base, the discharged foam is applied twice, i.e. once at the end of the pass to the edge, and again as it starts over above the previously applied foam, until the carriage can adjust to an unsprayed area.
Field applied roofing foam surface membranes are rigid polyurethane foam surface membranes, such as manufactured by Stepan Company of Pennsylvania under the trade name STEPANFOAMS®.
Stepan Company also manufactures a roofing product known as “low rise polyurethane adhesive”, brand name number RS 9514B, which is a concentrated polyurethane foam type adhesive often used to adhere solid rubber roof substrates to flat roof substrate structures.
However, it has not been known to imbed a low rise polyurethane adhesive with a woven polyester fabric or fiberglass layer and coat the formed substrate with silicone to create a monolithic integral roofing surface membrane for flat roofs, without the need for attaching a prefabricated roofing sheet, such as of vulcanized rubber, to the underlying roof substrate.
Furthermore, Dow Corning Corporation of Midland, Michigan manufactures silicone-based roofing coatings for weatherproofing reasons and for resisting the effects of ultraviolet light, such as the POLYCOAT® R-4000 silicone roof coating. Other prior art coatings are described in U.S. Pat. No. 3,607,972 of Kiles, et al, assigned to Dow Corning corporation, such as a room temperature vulcanizable siloxane-based block copolymer.
U.S. Pat. No. 5,253,461 of Janoski, assigned to Tremco, Inc. describes a cold-process built-up roofing system, which includes a curing adhesive with tarpaper and asphalt. The adhesive in its uncured state is substantially flowable, comprising asphalt and a compatibilizer and optionally a filler, dispersed in a curable polyisocyanate prepolymer. However, in Janoski '461 the adhesive takes up to 10 hours to cure, unlike spontaneously cured polyurethane-based foams.
Among prior art devices for applying coatings include U.S. Pat. No. 5,381,597 of Petrove which describes a wheeled robotic device for installing shingles on roofs. While it does not concern spraying of urethane foam upon a flat roof, it does describe a movable, wheeled carriage for use upon a roof.
U.S. Pat. No. 5,620,554 of Venable, assigned to Carlisle Corporation of Syracuse, N.Y. describes an apparatus for making a composite roofing material, including a reel support for reels of prefabricated vulcanized rubber sheets, a polymeric film and fleece matting, wherein rollers advance the solid rubber sheet from its reel, which heat and stretch the rubber, binding it to the polymeric film and fleece matting.
However, in Venable '554, there must first be a reel of a prefabricated solid rubber sheet, not an spontaneously formed monolithic roofing surface membrane.
Moreover, U.S. Pat. No. 5,872,203 of Wen describes a polyurethane adhesive for bonding polymeric roofing sheets to flat roof decks, which includes a two-component curable mixture, such as a polyurethane prepolymer and a polyol.
In addition, British patent application GB 2,055,326A of CCG Roofing Contractors, Limited describes a prefabricated polymer board that includes two layers with a fabric mesh therein. However, the fabric mesh is mechanically imbedded between the two layers during fabrication forming, and does not describe imbedding a fabric spontaneously within a polyurethane foam as the spray-applied foam rises up and through the fabric.
U.S. Pat. No. 5,248,341 of Berry concerns the use of curved walls to accommodate spray paint applicators for curved surfaces, such as aircraft.
U.S. Pat. No. 5,141,363 of Stephens describes a mobile train which rides on parallel tracks for spraying the inside of a tunnel.
U.S. Pat. No. 5,098,024 of MacIntyre discloses a spray and effector which uses pivoting members to move an armature which holds a spray apparatus.
U.S. Pat. No. 4,983,426 of Jordan discloses a method for the application of an aqueous coating upon a flat roof by applying a tiecoat to a mastic coat.
U.S. Pat. No. 4,838,492 of Berry discloses a spray gun reciprocating device, wherein parallel tracks are used wherein each track is square in cross section, but further wherein each track guides a plurality of rollers thereon.
U.S. Pat. No. 4,630,567 of Bambousek discloses a spray system for automobile bodies, including a paint booth, a paint robot apparatus movable therein, and a rail mechanism for supporting the apparatus thereat.
U.S. Pat. No. 4,567,230 of Meyer describes a chemical composition for the application of a foam upon a flat roof.
U.S. Pat. No. 4,167,151 of Muraoka discloses a spray applicator wherein a discharge nozzle is moved transversally upon a frame placed adjacent and parallel to the surface having the foam being applied thereto. However, the applicator of Muraoka '151 does not solve the problem of excess foam being applied at the end of each transverse pass of the discharge nozzle.
U.S. Pat. No. 4,209,557 of Edwards describes a movable carriage for a nozzle applying adhesive to the back of a movably advancing sheet of carpeting. Similarly, Australian Pat. No. 294,996 of Keith describes a movable carriage for a nozzle applying a polyurethane foam coating to a movably advancing sheet.
U.S. Pat. No. 4,016,323 of Volovsek also discloses the application of foam to a flat roof.
U.S. Pat. No. 3,786,965 and Canadian Pat. No. 981,082, both of James, et al, describe a self-contained trailer for environmentally containing a dispenser for uniformly dispensing urethane foam upon a terrestrial surface, wherein the problem of “skewing” occurs at the completion of each pass at the boundary edges of the surface to which are urethane foam is being applied. James '965 employs self-enclosed gantry robots to move the fluid discharge nozzle over the terrestrial surface.
U.S. Pat. No. 3,667,687 of Rivking discloses a foam applicator device.
U.S. Pat. No. 1,835,402 of Juers describes an apparatus for spraying glass from a nozzle transversely along a flat surface and U.S. Pat. No. 3,027,045 of Paasche discusses a coating machine where the nozzle moves by a pivot arm.
U.S. Pat. No. 3,096,225 of Carr discloses a hand-held spray nozzle for depositing a continuous stranded material, such as glass.
U.S. Pat. No. 2,176,891 of Crom discloses an apparatus for applying coatings over curved surfaces, such as within ditches or other curved surfaces. Moreover, U.S. Pat. No. 4,210,098 of Harrison also discloses an apparatus for spraying insulation or other coatings upon curved surfaces.
Other related art incl
Juska Cheryl A.
Singh Arti R.
Walker Alfred M.
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