GRATING INSERT FOR RIGGING ROPE

Abstract

An insert is provided for use on industry standard gratings to prevent wear and damage to rigging ropes passing through the insert.

Claims

1. An insert for guiding rigging ropes through a grating comprising spaced-apart cross-bar members operatively coupled to spaced-apart load bar members of a predetermined height, the insert comprising: a) a base member comprising a top surface; and b) at least one rope guide extending downwardly from the top surface a distance greater than the predetermined height.

2. The insert as set forth in claim 1, wherein the base member comprises a perimeter further comprising at least one rounded shoulder.

3. The insert as set forth in claim 1, wherein the at least one rope guide comprises a rounded inlet.

4. The insert as set forth in claim 1, wherein the at least one rope guide comprises an elongated configuration.

5. The insert as set forth in claim 1, wherein the at least one rope guide comprises a width that corresponds to a space between adjacent load-bar members.

6. The insert as set forth in claim 5, wherein the width of the at least one rope guide is selected such that at least some force is required to insert the at least one rope guide between adjacent load-bar members.

7. The insert as set forth in claim 1, further comprising at least two rope guides.

8. The insert as set forth in claim 1, wherein the insert is comprised of nylon.

9. The insert as set forth in claim 8, wherein the nylon comprises an additive to protect the insert from ultraviolet light.

10. A method for rigging a rope through a grating comprising spaced-apart cross-bar members operatively coupled to spaced-apart load bar members of a predetermined height, the method comprising the steps of: a) providing an insert for use on the grating, the insert comprising: i) a base member comprising a top surface, and ii) at least one rope guide extending downwardly from the top surface a distance greater than the predetermined height; b) placing the at least one rope guide between a pair of the spaced-apart load bar members; and c) passing at least one rigging rope through the at least one rope guide.

11. The method as set forth in claim 10, wherein the base member comprises a perimeter further comprising at least one rounded shoulder.

12. The method as set forth in claim 10, wherein the at least one rope guide comprises a rounded inlet.

13. The method as set forth in claim 10, wherein the at least one rope guide comprises an elongated configuration.

14. The method as set forth in claim 10, wherein the at least one rope guide comprises a width that corresponds to a space between adjacent load-bar members.

15. The method as set forth in claim 14, wherein the width of the at least one rope guide is selected such that at least some force is required to insert the at least one rope guide between adjacent load-bar members.

16. The method as set forth in claim 10, wherein the insert comprises at least two rope guides.

17. The method as set forth in claim 10, wherein the insert is comprised of nylon.

18. The method as set forth in claim 17, wherein the nylon comprises an additive to protect the insert from ultraviolet light.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a perspective view depicting a prior art grating having load bar members and cross-bar members.

[0027] FIG. 2 is a perspective view depicting one embodiment of a grating insert that can be used with the grating of FIG. 1.

[0028] FIG. 3 is a perspective view depicting the grating insert of FIG. 2 installed on the grating of FIG. 1.

[0029] FIG. 4 is a top perspective view depicting the grating insert and grating of FIG. 3.

[0030] FIG. 5 is a front elevation view depicting the grating insert and grating of FIG. 3.

[0031] FIG. 6 is a bottom perspective view depicting the grating insert and grating of FIG. 4.

[0032] FIG. 7 is a side elevation view depicting the grating insert and grating of FIG. 3.

[0033] FIG. 8 is a perspective view depicting the grating insert and grating of FIG. 3 having rigging ropes passing through the rope guides of the grating insert, the ropes deflected along the axes of the rope guides.

[0034] FIG. 9 is a perspective view depicting the grating insert and grating of FIG. 3 having rigging ropes passing through the rope guides of the grating insert, the ropes deflected orthogonally to the axes of the rope guides.

[0035] FIG. 10 is a side elevation view depicting the grating insert and grating of FIG. 7 having rigging ropes passing through the rope guides of the grating insert, the ropes deflected 90° above the grating insert.

[0036] FIG. 11 is a front elevation view depicting the grating insert and grating of FIG. 5 having rigging ropes passing through the rope guides of the grating insert, the ropes deflected 30° from the horizontal below the grating insert.

DETAILED DESCRIPTION OF EMBODIMENTS

[0037] A grating insert to be used on the industry standard sized grating is provided. In some embodiments, the grating insert can be installed on an industry grating with little or no effort from the operative/technician.

[0038] Referring to FIG. 2, one embodiment of grating insert 10 is shown. In some embodiments, insert 10 can comprise top surface 12 further comprising rounded shoulders 14 disposed at least partially around the perimeter of insert 10 to prevent any snagging with a rigging rope. In some embodiments, insert 10 can comprise tote hole 16 to provide means for toting or carrying insert 10. Tote hole 16 can be configured to be placed on a carabiner clip (not shown) to hang from a technician's belt or safety straps while they ascend or descend in a grating structure. In some embodiments, insert 10 can comprise one or more elongated rope slots 18 to form rope guides extending downwardly from top surface 12 of base member 11. In the illustrated embodiment, insert 10 is shown with two rope slots 18. Slots 18 can further comprise rounded inlets 20, having a similar rounded profile to shoulders 14, to reduce friction and snagging with a rigging rope placed through the slots. Referring to FIGS. 3 and 4, one embodiment of insert 10 is shown installed on grating G.

[0039] Referring to FIGS. 5 to 7, insert 10 is shown comprising rope guide tubes 22 extending downwardly from top surface 12 in between load bars L of grating G. In some embodiments, the length of rope guide tubes 22 can be selected to be longer than the height, “h”, of load bars L such that the bottom edges of rope guide tubes 22 extends below the bottom edge of load bars L, as shown in FIGS. 5 to 7. In some embodiments, width “w” of rope guide tubes 22 can be wide enough to pass between load bars L having spacing A therebetween so that there is at least some resistance to install rope guide tubes 22 between load bars L so as to keep insert 10 in place in grating G when ropes are run through rope guide tubes 22, and to prevent insert 10 from lifting easily or accidentally off of grating G when in use.

[0040] It is very important to clear away any debris from the chosen area of grating G the operative/technician chooses to place insert 10 in order to get good contact with the top of grating G. If grating G is not bent or obstructed, insert 10 can then be placed as described above, preferably in openings in grating G that are free from any type of debris or blockage.

[0041] In some embodiments, insert 10 can comprise two elongated rope guide tubes 22 that can be designed to fit into the elongated openings of standard sized grating. By comprising two rope guide tubes 22 that can be placed in adjacent openings of grating G separated by a load bar member L, insert 10 can be prevented from moving around or twisting on grating G. In addition, insert 10 having more than one rope slot 18 can prevent having to use more than one rope in a single rope slot 18 and, thus, prevent “rope on rope” friction.

[0042] Referring to FIGS. 8 and 9, a rope 24 is shown in each of rope slots 18. Ropes 24 can not only pass straight through rope slots 18 vertically, but can also be deflected from the vertical in any azimuth angle about rope slot 18, and can be further deflected either above or below insert 10. In FIG. 8, ropes 24 are shown deflected along an axis that is parallel to the longitudinal axes of elongated rope slots 18, wherein ropes 24 can contact along rounded shoulders 20. In FIG. 8, there is a rope 24 shown through tote hole 16, which is an illustration of where a rope 24 is not to be placed through as tote hole 16 is not large enough to provide friction-free movement therethrough for rope 24; tote hole 16 is intended as a means for carrying insert 10. In FIG. 9, ropes 24 are shown deflected along an axis that is orthogonal to the longitudinal axes of elongated rope slots 18, wherein ropes 24 can contact along rounded shoulders 20.

[0043] Referring to FIG. 10, ropes 24 are shown deflected 90° from vertical above top surface 24, wherein ropes 24 can contact along rounded shoulders 20. Referring to FIG. 11, ropes 24 are shown deflected 30° from horizontal below insert 10.

[0044] In some embodiments, insert 10 can be made of Super Tough Nylon (STN) with a ultraviolet (“UV”) light protection additive to the resin when formed at the manufacturing stage. STN has a deflection temperature rating of 270° F., and a melting temperature at approximately 505 F°.

[0045] In some embodiments, the UV light protection additive can comprise one or more of UV Absorbers, Quenchers and Hindered Amine Light Stabilizers (“HALS”), and other additives as well known by those skilled in the art to protect against degradation caused by UV light.

[0046] In some embodiments, Absorbers can comprise a type of light stabilizer that can function by competing with the chromophores to absorb UV radiation. Absorbers change harmful UV radiation into harmless infrared radiation, or heat that is dissipated through the polymer matrix. Carbon black is one of the most effective and commonly used light absorbers. Another UV absorber is rutile titanium oxide, which can be effective in the 315-400 nm range. Hydroxybenzophenone and hydroxyphenylbenzotriazole are also well-known UV stabilizers that can have the advantage of being suitable for neutral or transparent applications. Other UV absorbers can include oxanilides for polyamides, benzophenones for PVC and benzotriazoles and hydroxyphenyltriazines for polycarbonate. UV absorbers can have the benefit of low cost but may be useful only for short-term exposure.

[0047] In some embodiments, Quenchers can Quenchers return excited states of the chromophores to ground states by an energy transfer process. The energy transfer agent can function by quenching the excited state of a carbonyl group formed during the photo-oxidation of a plastic material, and through the decomposition of hydroperoxides. This can prevent bond cleavage and ultimately the formation of free radicals.

[0048] In some embodiments, HALS can comprise long-term thermal stabilizers that can act by trapping free radicals formed during the photo-oxidation of a plastic material and, thus, limiting the photodegradation process. The ability of Hindered Amine Light Stabilizers to scavenge radicals created by UV absorption can be explained by the formation of nitroxly radicals through a process known as the Denisov Cycle. Although there are wide structural differences in the HALS products commercially available, all share the 2,2,6,6-tetramethylpiperidine ring structure. HALS are some of the most proficient UV stabilizers for a wide range of plastics. For example, HALS has enabled the growth of polypropylene in the automotive industry. While HALS are also very effective in polyolefins, polyethylene and polyurethane they are not useful in PVC.

[0049] As all three of UV Absorbers, Quenchers and HALS function by different mechanisms, they can be combined into synergistic UV absorbing additives. For example, benzotriazoles can be combined with HALS to protect pigmented systems from fading and color changes.

[0050] STN also has a tensile strength of 8000 Mpa, making inserts 10 comprised of STN extremely durable for in the field use. Table 1 below sets out physical characteristics of STN.

TABLE-US-00001 TABLE 1 Properties Condition Value Test Method Comment Modulus of elasticity @ 73° F. 245,000 psi ASTM D 638 (tensile test) Wear (K) factor Against Steel, 200*10.sup.−10 in.sup.3- ASTM D 3702 40 psi, 50 fpm min/ft- lbs-hr Tensile strength at yield @ 73° F. 7,200 psi ASTM D 638 Mechanical Elongation at break @ 73° F. 60 % ASTM D 638 Modulus of elasticity @ 73° F. 230,000 psi ASTM D 790 (flexural test) Impact strength (Izod) @ 73° F. 17.0 ft-lbs/in ASTM D 256 Rockwell hardness R scale 112 ASTM D 785 Coefficient of friction Dynamic, 0.28 ASTM D 3702 40 psi, 50 fpm Melting temperature 505 ° F. ASTM D 2133 Deflection temperature @ 66 psi 270 ° F. ASTM D 648 Thermal Deflection temperature @ 264 psi 147 ° F. ASTM D 648 Thermal expansion 6.7*10.sup.−4 in/in/° F. ASTM D 696 (CLTE) Moisture absorption @ 24 hrs, 1.2 % ASTM D 570 73° F. Other Moisture absorption @ saturation, 6.7 % ASTM D 570 73° F. Flammability (UL94) HB 1) 1) 0.81 mm

[0051] These inserts will more than likely be placed in bags for shipping from job site to job site, which means they will be put through a bit of abuse at times. Having a durable material for inserts 10 to be made from STN can provide a safe, reliable product for all rigging operatives and technicians.

[0052] Although a few embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications can be made to these embodiments without changing or departing from their scope, intent or functionality. The terms and expressions used in the preceding specification have been used herein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the invention is defined and limited only by the claims that follow.