Debris Barrier

FIG. 1 is a perspective view illustrating an idealized high rise construction structure and a plurality of installed debris barriers in accordance with the present invention.

FIG. 2 is an enlarged perspective view, partially broken away, illustrating a debris barrier system incorporating a debris barrier in accordance with the present invention;

FIG. 3 is an enlarged fragmentary perspective view, partially broken away to show detail, of a top portion of the debris barrier of FIG. 2; and

FIG. 4 is an enlarged fragmentary perspective view of a lower portion of the debris barrier of FIG. 2.

With reference to the drawings wherein like numerals represent like parts throughout the figures, a debris barrier system designated generally by the numeral 10 incorporates a debris barrier 12 to provide a safety system having particular applicability in high rise construction projects. An idealized high rise construction structure is generally designated by the numeral 14 in FIG. 1. It will be appreciated that a debris barrier 12 may be installed at each floor or level of the structure 14.

The debris barrier system 10 is employed to prevent debris, tools, materials and other objects from being accidentally kicked, blown or from falling off of the floor slab of the high rise construction project. In addition, the debris barrier in combination with required cables is capable of withstanding substantial impacts so as to also prevent workers from accidentally falling off the uncompleted construction structures. The barrier system 10 may also function as a windbreak to decrease the wind currents on the floor slab. The barrier system 10 additionally provides enhanced visibility compared to prior related systems.

At each level of the structure 14, the floor slab 20 at the perimeter is at least partially open. Vertical support posts 22 extend from the horizontal floor slab 20 at or near the floor slab periphery. A safety cable 24 is suspended between the posts 22 and extends at least a peripheral portion or an approximate peripheral portion of the floor slab 22. Pertinent safety regulations conventionally mandate that the safety cable 24 must be located at a substantially uniform height, typically in the range of 42 to 60 inches, above the floor slab 20. A second safety cable 26 (FIG. 2) which may be identical in form and function to safety cable 24, is typically suspended between posts 22 approximately midway between cable 24 and the floor slab 20 or at a pre-selected height in generally parallel relationship therewith. Other cables may also be provided. The cables may also be suspended from auxiliary posts or structures rather than the illustrated support posts 22. It should be appreciated that safety cables 26 and 24 are conventionally mandated for high rise building construction projects and their specific construction and method of mounting are conventional.

The debris barrier 12 in accordance with the present invention comprises a flexible mesh netting 30 which preferably has a generally uniform width and a semi-continuous-type form. The netting may be manufactured in 50 foot sections. In one embodiment, the uniform width of the netting of the finished barrier product is approximately 6 feet. The finished netting 30 has an upper border 32 and a parallel lower border 34 as well as longitudinally spaced parallel side borders 36 and 38 for each netting section. The lower border 34 may be a single ply edge of netting or a dual ply netting band.

The mesh netting 30 in a preferred embodiment comprises a 1/8 inch woven mesh of "arlyn" yarn composition having a 0.028 mil diameter and a weight of approximately 8 ounces per square yard. The woven yarn composition is composed of pigmented flexible foam polyvinyl chloride having approximately 78% foam vinyl and 22% 1000 denier polyester composition. The netting fabric in one embodiment is heat set and blown to the desired specifications and is flame retardant to a degree which is essentially self-extinguishing. The woven netting fabric has approximately 7 strands per inch warp and 5 strands per inch fill (weft). The tensile strength of the described netting material is warp-100 lbs./sq.in. minimum and fill-74 lbs./sq. in. minimum (ASTM-Dl682-75). The Mullen Burst strength is determined to be a minimum of 270 lbs. per square inch (ASTM-D3786). The netting fabric is also abrasion resistant having a 500 cycle rating of 4.5 minimum warp and 4.5 minimum fill (ASTM-4157-82). The netting may also have a safety pigment which is resistant to ultra violet radiation.

The upper border 32 is formed by folding and looping the netting fabric so as to form a longitudinally extending mesh channel 40 as best illustrated in FIG. 3. A cord 42 is inserted through the channel 40. Alternatively, the channel defining netting is looped over the cord and secured together. The cord 42 extends the longitudinal length of the netting and cooperates to provide an upper reinforcement-type border structure to the netting. The upper border 32 typically has a transverse width of approximately one-half inch. In one embodiment, the cord 42 is constructed from a DuPont #728 high tenacity nylon material having a diameter of 0.170 inch and a tensile strength of 1200 lbs. Mesh channels are also formed at the side borders 36 and 38 and the cord 42 extends therethrough. The debris barrier netting may thus be essentially described as comprising an elongated flexible rectangular section of woven material having a flexible reinforced structure at the two opposing ends and the top border thereof.

A heavy duty, nylon filament strip of webbing 50 is stitched or otherwise fastened to one side of the mesh netting 30 so as to extend longitudinally generally parallel to the upper border 32. The webbing typically has a transverse width in the range of approximately 11/2 to 21/2 inches and a minimum break strength of 6000 lbs. In a preferred embodiment, the nylon webbing strip 50 is uniformly spaced approximately 5 feet from the upper border 32. The webbing strip 50 functions to provide a reinforcement panel for fastening or anchoring the netting to the floor slab.

The lower border 34 may have a transverse width of 3/4 inch. In some embodiments, the lower border is essentially the edge of a single ply of the mesh netting 30. The foregoing described debris barrier 30 has been tested in a rigid 10 foot by 10 foot frame and found to withstand a maximum static load of 1,200 lbs.

The described debris barrier 30 is installed by suspending portions of the upper border 32 from cable 24. Clips 60, having a continuous compound U-shaped configuration, are slipped through an opening in the mesh netting just below the border cord 42 at longitudinally spaced locations along the netting. In one embodiment, the clips are manufactured from 0.156 gauge steel. The clips 60 are typically located every two feet along the netting. Each clip 60 is dimensioned and bifurcated to allow the clip to slide over the cable at one angular orientation of the clip. Upon rotation (in the general direction of the FIG. 3 arrow) and release of the clip 60, the clip and connected netting is freely suspended from the cable 24, as best illustrated in FIGS. 2 and 3. The foregoing installation process is replicated until the upper portion of the entire section of netting is eventually suspended from the cable as illustrated in FIGS. 1 and 2.

The debris barrier 30 is preferably dimensioned relative to the height of the cable 24 above slab 20 so that the netting portion underlying and between the strip 50 and the lower border 34 is horizontally positionable in a quasi-smooth surface to surface relationship along the floor slab 20. The resultant horizontal barrier component essentially forms a debris floor flap 62 which rests on the floor slab and extends generally perpendicularly to the vertically suspended netting portion 64 of the debris barrier. The webbing strip 50 is dimensioned and positioned relative to both the netting and the cable height so that it is generally located in the vicinity of the formed intersection between the flap 62 and the vertical netting portion 64. The webbing strip 50 is positioned toward the second border portion 34 from the intersection so as to horizontally rest on the floor slab 20. For example, for an application where the top safety cable 24 is 60 ins. above the floor slab, the transverse distance between the upper border 32 and the webbing strip 50 is approximately 60 ins. and the flap 62 is approximately 12 inches wide.

Nails 70 or other suitable fasteners are driven through conventional roofing fastener plates 72 to secure the debris barrier to the floor slab 20. The plates 72 are positioned at longitudinally spaced positions along the webbing strip 50. A powder actuated driver other means may be suitably employed to drive the nails 70 into the floor slab to thereby secure the lower portions of the debris barrier to the floor slab. The fasteners are preferably spaced approximately every 5 feet along the debris barrier.

A debris barrier 12 in accordance with the present invention which was installed as described herein has been found to withstand an orthogonally directed impact against the vertical netting portion 64 in excess of 900 lbs. It should be appreciated that the debris barrier system 10 as described does not require the conventional rigid toe board yet provides a debris barrier which is at least equal, and in many cases exceeds, the impact specifications provided by safety barriers employing the conventional toe board-type structure.

The adjacent debris barrier sections may be clipped together by means of clips 60 or other fasteners by overlapping end portions of the sections and fastening together the overlapping portions. It should be appreciated that the foregoing debris barrier system 10 can be both installed and dismounted in a very efficient manner. The debris barrier may be dismounted by pulling the fasteners from the floor slab and releasing the clips 60 or other cable/netting fasteners. The clips 60 may be released from the cable by merely raising the clips and the suspended netting, twisting the clip and releasing same from the cable by allowing the clip/netting to fall toward the floor slab under the force of gravity.

While a preferred embodiment of the foregoing invention has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.