Methods and apparatus for installing a safety line

[0002] This application claims the benefit of U.S. provisional patent application No. 60/183,543, filed Feb. 18, 2000.

[0003] The present invention relates to personal safety equipment and in a preferred application for a preferred embodiment, to a safety line system that may be conveniently secured to and removed from a concrete beam having reinforcing bars which project outward from the beam.

[0004] Various occupations and/or endeavors place people in precarious positions at relatively dangerous heights. As a result, many types of safety apparatus have been developed to reduce the likelihood of a fall and/or injuries associated with a fall. Much of the existing equipment is designed for a particular application and thus, is not necessarily well suited for use in more than one type of environment. With respect to the present invention, it was determined that a need existed for a safety device that could be readily attached to and detached from concrete beams of the type used in large public works projects and the like. One object of the invention was to design a system that could be secured relative to various reinforcement bar configurations on different types of concrete beams, without altering the beams or imposing any requirements on the manufacture of the beams. Another object of the invention was to design such a system with a horizontal safety line that would extend substantially the entire length of the beam and/or selectively pivot to alternative positions relative to the beam.

[0005] One aspect of the present invention involves the anchoring of a personnel safety system to a concrete beam of the type having a top surface and upwardly protruding reinforcement bars. The system includes a base plate having at least one slot which extends parallel to the mounting surface on the beam. Left and right hook members are slidably mounted within respective portions of the at least one slot and preferably open toward one another. Once the hook members are maneuvered into engagement with respective reinforcement bars, bolts are inserted through the base plate and threaded into respective hook members to secure the latter in place relative to the former. Each bar is clamped between a respective hook member and axially displaced bearing surfaces that face toward the respective hook member. An advantage of this system is that it accommodates beams having different reinforcement bar arrangements and thus, does not require alteration of the beams themselves.

[0006] Another aspect of the present invention involves the pivoting of a safety line relative to its support structure. Opposite ends of the safety line are anchored to opposite ends of a concrete beam or other support structure. Stanchion assemblies are positioned at intermediate positions along the safety line and secured to the beam. Each stanchion assembly includes a beam engaging base, and a post which is selectively pivotal relative to the base. The posts pivot about a common pivot axis which aligns with the anchored ends of the safety line. Additional supports are also secured between respective end stanchions and respective end anchors for the safety line. Each stanchion assembly also includes a latch which selectively releases the post for pivoting to alternative positions relative to the base. An advantage of this system is that the safety line may be moved to different positions depending upon circumstances. For example, it may be desirable to pivot the posts to parallel horizontal orientations for transportation purposes.

[0007] On a preferred embodiment, the foregoing features are incorporated into a horizontal safety line system which may be secured to a beam before it is loaded onto a truck for delivery to a job site. To the extent that people are required to stand on and/or walk along the beam (during loading, unloading, and/or installation of the beam), the system provides a suitable, fall-arrest safety line. Additional features and/or advantages may become more apparent from the more detailed description which follows.

[0008] With reference to the Figures of the Drawing, wherein like numerals represent like parts and assemblies throughout the several views,

[0009] FIG. 1 is a side view of one end of a horizontal safety line system constructed according to the principles of the present invention;

[0010] FIG. 2 is an end view of a stanchion assembly that is part of the system shown in FIG. 1;

[0011] FIG. 3 is a side view of the assembly shown in FIG. 2;

[0012] FIG. 4 is an enlarged and partially sectioned side view of the assembly shown in FIG. 3;

[0013] FIG. 5 is an end view of a base portion that is part of the assembly shown in FIG. 2;

[0014] FIG. 6 is a top view of the base portion shown in FIG. 5;

[0015] FIG. 7 is a side view of the base portion shown in FIG. 5;

[0016] FIG. 8 is a top view of a hook member that is part of the base portion shown in FIG. 5;

[0017] FIG. 9 is an end view of the hook member shown in FIG. 8;

[0018] FIG. 10 is an end view of an end anchor assembly that is part of the system shown in FIG. 1;

[0019] FIG. 11 is a side view of the assembly shown in FIG. 10;

[0020] FIG. 12 is a top view of the assembly shown in FIG. 11;

[0021] FIG. 13 is a perspective view of one end of another horizontal safety line system constructed according to the principles of the present invention; and

[0022] FIG. 14 is an exploded perspective view of an end anchor assembly that is part of the system shown in FIG. 13.

[0023] A first safety system constructed and installed according to the principles of the present invention is designated as 100 in FIG. 1. In a preferred application, the system 100 provides a horizontal safety line 180 relative to a concrete beam 90 of the type having a top surface 91 and upwardly protruding reinforcement bars 92 and 94-97. However, the present invention may be applicable in other instances, as well. For example, the anchoring structure incorporated into the system 100 may be used to support other types of personal safety devices, and/or the line pivoting structure incorporated into the system 100 may be used relative to other types of support structures.

[0024] Generally speaking, the system 100 includes a stanchion assembly 110, an end anchor assembly 140, a safety line 180, and a connector 190. An opposite end of the safety line 180 (not shown) is preferably secured to a similar stanchion assembly 110 and a similar end anchor assembly 140, but the present invention is not necessarily limited to such an arrangement. For example, an opposite end of the safety line 180 could simply be secured to something on site, such as a dump truck (with the only keys to the truck preferably in the pocket of the person relying upon the safety line 180). Also, one or more additional, intermediate stanchion assemblies 110 may be disposed along the safety line 180 to provide intermediate support, depending upon the overall length of the line 180.

[0025] A stanchion assembly 110 is shown by itself in FIGS. 2-3. The assembly 110 may be described in terms of a post 120 which selectively pivots relative to a base 210. A cable supporting bracket 128 is mounted on an upper end of the post 120. The bracket 128 includes overlapping fingers which are axially spaced apart from one another. The fingers are configured to both retain the safety line 180 and facilitate passage of a connector along the safety line 180 from one side of the post 120 to the other. A chain supporting bracket 129 is mounted on an intermediate portion of the post 120. The bracket 129 includes a circular opening having a diameter which exceeds both the width and the thickness of the links in the chain 190, and an adjoining slot having a width which is greater than the thickness of the chain links, but less than their width.

[0026] FIG. 4 shows the lower end of the post 120 in greater detail. The post 120 may be described as a square tube. Opposing bars 130 are inserted into the lower end of the post 120 and secured in place by respective pairs of transversely extending, mating nuts and bolts 102 and 103. An intervening spacer 139 is sandwiched between the bars 130 proximate their upper ends, and an intervening support 135 is sandwiched between the bars 130 proximate their middle portions. The lower ends of the bars 130 straddle a plate 230 on the base 210 (described below) and are rotatably secured thereto by mating nut and bolt 203. A T-shaped latch includes a longitudinal member or shaft 132 and a transverse member or pin 133. The longitudinal shaft 132 has a first end which extends through a hole in the support 135, and second end which is rigidly secured to the transverse pin 133. A helical coil spring 134 is disposed on the longitudinal shaft 132 and is compressed between the transverse pin 133 and the support 135. The spring 134 biases the transverse pin 133 toward the plate 230. A circular depression may be provided in the support 135 to retain or seat the proximate end of the spring 134.

[0027] The base 210 is shown by itself in FIGS. 5-7. The base 210 includes the plate 230 and an orthogonally extending flange 213. The base 210 is symmetrical about a plane which bisects the flange 213 and extends perpendicular to the plate 230. The bottoms of the plate 230 and the flange 213 lie flush against the top of the beam 90. A hole 239 extends through a central portion of the plate 230 to receive the bolt 203. Notches 231-233 extend into the upper edge of the plate 230 to retain the transverse pin 133 at respective orientations. When the pin 133 occupies the center notch 232, the post 120 extends vertically upward from the horizontal beam 90. When the pin 133 occupies either of the notches 231 or 233, the post 120 defines an angle of twenty degrees relative to vertical.

[0028] Laterally extending slots 234 and 235 extend through the plate 230 proximate its lower edge. The slots 234 and 235 are sized and configured to receive and accommodate lateral repositioning of respective hook members 224 and 225. The hook members 224 and 225 are slidably secured to respective U-shaped blocks 244 and 245 by respective spring pins 242 (shown in FIG. 6). The U-shaped blocks 244 and 245 open toward one another. The hook member 224 (which is a mirror image of the hook member 225) is shown in greater detail in FIGS. 8-9. A threaded bolt hole 221 extends transversely through a first portion of the hook member 224 and toward an opposing second portion of the hook member 224. A notch 223 in the second portion is contoured to receive and hook a portion of a reinforcement bar. A transversely extending groove is provided in the top of the hook member 224 to accommodate the pin 242 and thereby slidably connect the hook member 224 to the U-shaped block 244.

[0029] An end anchor assembly 140 is shown by itself in FIGS. 10-12. The assembly 140 includes a base plate 150 and an orthogonally extending anchorage member 160 which are rigidly secured to one another (by welding or other suitable means). The assembly 140 is symmetrical about a plane which bisects the anchorage member 160 and extends perpendicular to the plate 150. The bottom of the plate 150 lies flush against the top of the beam 90. A U-bolt 169 is secured to a distal end of the anchorage member 160 for purposes of anchoring an end of the safety line 190 relative thereto. Also, a hole 168 extends through an adjacent portion of the anchorage member 160 for purposes of anchoring an end of the chain 180 relative thereto.

[0030] Laterally extending slots 154 and 155 (similar in size and shape to the slots 234 and 235) extend through the plate 150. The slots 154 and 155 are sized and configured to receive and accommodate lateral repositioning of respective hook members 224 and 225 (identical to those on the stanchion assembly 120). The hook members 224 and 225 are secured to respective U-shaped blocks 244 and 245 by spring pins 242 (also identical to those on the stanchion assembly 120). The commonality of parts is not critical to the operation of the present invention, but is considered advantageous to the extent that it contributes to manufacturing efficiency.

[0031] The preferred embodiment system 100 is installed after determining the desired span of the safety line 180. The end anchor assemblies 140 are positioned at the opposite ends of the safety line 180 with the anchorage members 160 extending toward one another. The assemblies 140 are then secured in place relative to the most suitable reinforcement bars (designated as 96 and 97 in FIG. 10). More specifically, the opposing hook members 224 and 225 are positioned on opposite, outer sides of the reinforcing bars 96 and 97 and then maneuvered until the bars 96 and 97 are inside the notches 223 on respective hook members 224 and 225. The bolts 204 and 204 are then tightened so that the bars 96 and 97 are clamped between respective hook members 224 and 225 and respective U-shaped blocks 244 and 245. As a result, each bar is clamped between bearing surfaces which are diametrically opposed and axially offset relative to one another (relative to the longitudinal axis of the bar).

[0032] A respective stanchion assembly 110 is positioned inside each of the end anchor assemblies 140 with the chain bracket 129 and the flange 213 extending toward the adjacent end anchor assembly 140. The arrangement is preferably such that the safety line 180 will extend at an angle between thirty and forty degrees relative to the beam 90. In a manner similar to the end anchor assemblies 140, the stanchion assemblies 110 are secured in place relative to the most suitable reinforcement bars (designated as 94 and 95 in FIG. 5). The flange 213 is positioned to extend between the two bars 94 and 95. A first end of the chain 190 is secured to the U-bolt 169, and an opposite end of the chain 190 is inserted through the chain bracket 169. The chain 190 is pulled taut, and as many links as possible are pulled through the hole in the bracket 169 before a particular link is maneuvered into the slot in the bracket 169.

[0033] At each end of the system 100, a tensioning device or turnbuckle 188 is connected in series between the anchorage member 160 and an energy absorbing device 184. A sleeve member 182 is connected to an opposite end of the energy absorber 184, and an end portion of the safety 180 is routed about the sleeve member 182. Intermediate portions of the safety line 180 are maneuvered through respective brackets 168 on the posts 120. Then, with the line 180 pulled taut, portions of the line on opposite sides of the sleeve member 182 are secured together (by cable clips 186 or other suitable means). Tension in the line 180 may be increased (or decreased) by adjusting the turnbuckle 188. The position of the line 180 relative to the beam 90 may be adjusted by pulling upward on each pin 133 and pivoting each post 120 to an alternative position. To minimize resistance to pivoting, the common pivot axis of the posts 120 should align with the line and chain connection points on the end anchor assemblies 140, and the connection points should be fitted with swivels.

[0034] FIG. 13 shows a second safety system 300 constructed and installed according to the principles of the present invention. As suggested by the common reference numerals, the system 300 is similar in many respects to the first system 100. Accordingly, the description of the second system 300 will focus primarily on the distinctions.

[0035] The system 300 includes a stanchion assembly 110′, an end anchor assembly 340, a safety line (not shown), and a connector 190′. The system 300 is installed and operated in much the same manner as the system 100, except that an energy absorber 184 is interconnected between the stanchion assembly 110′ and a first end of a line tensioner 188, and an opposite, second end of the line tensioner 188 is secured to the safety line.

[0036] There are three noteworthy distinctions between the stanchion assembly 110′ and the stanchion assembly 110. First, the post 120′ is welded, rather than bolted, to the bars 130′. Second, the cable supporting bracket 128 has been replaced by a cable supporting bracket 328 having an additional flange that is configured to receive and support a line anchoring bolt 388. Third, the bracket 129 has been replaced by a similarly configured bracket 329 that is secured to a different part of the post 120′ by means of two mating nuts and bolts.

[0037] The end anchor assembly 340 is shown in greater detail in FIG. 14. There are three noteworthy distinctions between the end anchor assembly 340 and the end anchor assembly 140. First, only the chain 190′ extends between the stanchion 110′ and the end anchor assembly 340. Second, the hook-shaped anchorage member 160 has been replaced by a U-bolt 360. The distal ends of the U-bolt 360 insert through respective holes 356 in the plate 350 and mate with respective nuts 366. Third, the hook members 224 and 225 have been replaced by hook members 224′ and 225′ that have a protruding flange or shoulder 322 to provide additional bearing surface.

[0038] Like the plate 150, the plate 350 has slots 354 and 355 sized and configured to receive and accommodate lateral repositioning of respective hook members 224′ and 225′. The hook members 224′ and 225′ are secured to respective U-shaped blocks 244 and 245 by spring pins 242. For reasons of manufacturing efficiency, the hook members 224′ and 225′ are made identical to one another, and the blocks 244 and 245 are made identical to one another, and the left side parts are then rotated one hundred and eighty degrees relative to the right side parts. As a result, the pins 242 insert into opposite facing sides of respective blocks 244 and 245. Bolts 204 and 205 are inserted through respective washers 206 and 207 and respective slots 354 and 355, and then threaded into respective hook members 224′ and 225′.

[0039] Although the present invention has been described with reference to specific embodiments and a particular application, this disclosure will enable those skilled in the art to recognize additional embodiments, improvements, and/or application that incorporate the essence of the present invention. Accordingly, the scope of the present invention should be limited only to the extent of any allowed claims.