NZ758776A - Cable Lifeline Assembly - Google Patents

Abstract

The present invention is directed to a cable lifeline assembly 10 installed on a structure at heights such as a ladder 12. The cable lifeline assembly 10 broadly comprises: 1. an energy absorbing device 14 adapted to mount to a first mounting arrangement 16 associated with the ladder 12; 2. a cable 18 at one end connected to the energy absorbing device 14, the cable 18 adapted to provide detachable coupling for a person 19 to arrest them in the event of a fall; 3. a second mounting arrangement 20 adapted to mount to the ladder 12; 4. a tensioning device 22 connected to an opposite end of the cable 18 and being associated with the second mounting arrangement 20 for tensioning of the cable 18 le 18 at one end connected to the energy absorbing device 14, the cable 18 adapted to provide detachable coupling for a person 19 to arrest them in the event of a fall; 3. a second mounting arrangement 20 adapted to mount to the ladder 12; 4. a tensioning device 22 connected to an opposite end of the cable 18 and being associated with the second mounting arrangement 20 for tensioning of the cable 18

Description

CABLE LIFELINE ASSEMBLY Technical Field The present invention relates broadly to a cable ne assembly and is directed more particularly to a vertically oriented cable lifeline assembly for installation on a structure at heights, typically in the form of a ladder.

Background of Invention In managing safety at heights there is generally a requirement for fall arrest where a person is tethered to a permanent static lifeline. The static lifeline is typically installed on a roof in a horizontal disposition with its opposing ends mounted to the roof or other structure at heights via an anchor ly. The person is releasably coupled to the static lifeline via a shuttle which glides along the lifeline as the person ses the roof. The ne system generally incorporates energy absorbing capabilities which in the event of a fall minimises damage to equipment and structure associated with the system and importantly reduces impact on the person arrested by the system.

The applicant offers this shock absorbing capability in an innovative anchor assembly which progressively distorts under sudden load experienced in the event of a fall. Australian patent no. 6424 and Australian patent application no. 2016257768 disclose anchor assemblies of this nature. An important feature of this design is the inclusion of one or more frangible joints in the anchor assembly which are intended to break on impact loading from a fall. The frangible joints provide l dissipation of the sudden load imparted on the lifeline system and, on fracturing of the frangible joints, the remainder of the anchor assembly distorts to further dissipate the energy of the fall.

Summary of Invention According to a first aspect of the t ion there is provided a cable lifeline assembly comprising: an energy absorbing device including a frangible element, said energy ing device adapted to mount to a first mounting arrangement associated with a structure at heights; a cable at one end connected to the energy absorbing device, the cable adapted to provide detachable coupling for a person to arrest them in the event of a fall; a tensioning device associated with a second mounting arrangement adapted to mount to the structure, said tensioning device connected to an opposite end of the cable and designed for tensioning of the cable whereby in the event of a fall the energy absorbing device is, under the additional force exerted on the cable by the person, plastically deformed thereby fracturing the frangible element which visually indicates deployment of said energy absorbing device.

According to a second aspect of the invention there is provided a cable lifeline assembly comprising: a first mounting arrangement associated with a structure at heights; an energy absorbing device including a frangible element, said energy absorbing device mounted to the first ng arrangement and adapted to connect to a cable which es detachable coupling for a person to arrest them in the event of a fall; a second mounting arrangement adapted to mount to the structure; a tensioning device associated with the second mount arrangement and adapted to connect to an opposite end of the cable for tensioning of the cable whereby in the event of a fall the energy absorbing device is, under the additional force exerted on the cable by the , plastically deformed thereby fracturing the frangible t which visually indicates deployment of said energy ing device.

Preferably the tensioning device includes an actuator configured to engage the opposite end of the cable for tensioning it on movement of the actuator in a first direction. More preferably the tensioning device es g means arranged to cooperate with the actuator for controlling ning of the cable via the biasing means on nt of the actuator in the first direction. Still more preferably the tensioning device also includes a housing containing the biasing means in the form of a compression spring designed to control ning of the cable. Further more preferably the tensioning device further includes a plunger configured to cooperate with the actuator and the compression spring for compression of said spring on movement of the actuator in the first direction. Further still more preferably the plunger is at least in part located within the housing and includes a guide which cooperates with an indicator associated with the housing to indicate the relative position of the plunger within the housing under the influence of the actuator being moved in the first direction, the guide and the indicator thereby ting the tension in the cable.

Preferably the actuator includes a ed fastener configured to ably engage the opposite end of the cable whereby rotation of the threaded fastener in either a clockwise or anti-clockwise direction effects its movement in the first direction for tensioning of the cable. More preferably the threaded fastener is in the form of an actuator nut which threadably engages a corresponding threaded portion at the opposite end of the cable.

Preferably the first mounting arrangement includes a first bracket ly d to mount to the ure at heights in the form of a ladder. More preferably the first bracket assembly includes a first bracket from which the energy absorbing device is ded, and a first member at an upper end mounted to the first bracket and at or nt a lower end adapted to mount to the ladder. Still more preferably the first mounting arrangement also includes a first clamping assembly configured to releasably clamp the first member to the ladder. Alternatively the first bracket is secured directly to the ladder.

Preferably the second mounting arrangement includes a second bracket assembly adapted to mount to the ladder. More preferably the second bracket ly includes a second member associated with the tensioning device, and a second clamping assembly configured to releasably clamp the second member to the ladder. Even more ably the second bracket assembly includes a second bracket d to the second member, the second bracket configured to provide anchorage for the cable via the tensioning device.

Preferably the energy absorbing device is elongate and es a deformable ediate portion formed continuous with and located between opposing end mounting portions connected to respective of the first mounting arrangement and the cable. More preferably the intermediate portion includes a pair of laterally disposed and plastically deformable members, said pair of able members in the event of a fall being configured to distort for elongation of said energy absorbing device. ably the energy absorbing device includes a l member located substantially between and connected to at least one of the pair of deformable members via the frangible element which is configured on elongation of the pair of deformable members to fracture thereby ing visual tion of the deployment of said energy absorbing . Alternatively or additionally the central member is connected to either of the opposing end mounting portions via the frangible element which is configured to fracture on elongation of the pair of members.

Preferably the energy absorbing device includes a visual indicator associated with both the central member and at least one of the pair of deformable members whereby elongation of the deformable members effects displacement of the central member relative to said at least one of the deformable members thus providing visual indication of the deployment of said energy absorbing device via the visual indicator. More preferably the visual indicator includes at least one indicator line which without distortion of the deformable members is substantially aligned whereas in the event of a fall the tor line is misaligned thereby visually revealing deployment of said energy absorbing . Alternatively or additionally the visual indicator is at least in part associated with the frangible element which on distortion of the deformable members fractures providing visual indication of deployment of the energy absorbing device. In this variation the ble element is one of a ity of frangible elements which at least in part define a recess configured to change shape on fracture of the frangible element thereby providing visual indication of the deployment of said energy absorbing . In these ments the energy absorbing device including the visual indicator is configured for visual tion to reveal whether or not it has deployed.

Preferably the cable lifeline assembly includes a secondary anchor for detachable tion to a d or the like associated with the person. More preferably the secondary anchor is formed integral with the energy absorbing device at the end mounting portion mounted to the first mounting arrangement. atively or additionally the secondary anchor is d to either the first member or the first bracket of the first bracket assembly.

Brief Description of Drawings In order to achieve a better understanding of the nature of the present invention a preferred embodiment of a cable ne assembly will now be described, by way of example only, with reference to the accompanying drawings in which: Figures 1A and 1B are perspective views of a cable lifeline assembly of an embodiment of the present invention shown installed on a structure at heights in the form of a ladder; Figure 2 is an enlarged ctive view of a first mounting arrangement and associated components taken from the cable lifeline assembly of the embodiment of figure 1; Figures 3A and 3B are enlarged perspective views of an energy absorbing device taken from the cable lifeline assembly of the embodiment of figures 1 and 2 shown installed on the first mounting arrangement in alternative led and exploded views; Figures 4A and 4B are enlarged perspective views of a second mounting ement and associated components taken from the cable lifeline assembly of the embodiment of figure 1 in alternative assembled and part exploded views; Figures 5A and 5B are front views of the energy absorbing device taken from the cable lifeline assembly of the embodiment of figure 1 shown respectively in its “before fall” and “after fall” configurations; Figures 6A and 6B are perspective views of a first or second clamping assembly taken from the first or second ng arrangement of the cable lifeline assembly of the embodiment of figure 1; Figures 7A and 7B to figures 11A and 11B are each front views of different embodiments of an energy absorbing device for inclusion in a cable ne assembly according to the invention shown in respective “before fall” and “after fall” configurations; Figure 12 is a ctive view of exemplary cable guides taken from the cable lifeline assembly of the embodiment of figure 1 installed on the ladder; Figures 13A and 13B are respective assembled and exploded views in front and side elevations of a second embodiment of a tensioning device for inclusion in a cable lifeline ly according to the invention; Figures 14A and 14B are respective assembled and exploded views in front and side elevations of a third embodiment of a tensioning device for inclusion in a cable lifeline assembly according to the invention; Figures 15A and 15B are respective led and exploded views shown in front and side elevations of a fourth embodiment of a tensioning device for inclusion in a cable lifeline assembly according to the invention; Figures 16A and 16B are tive assembled and detailed views shown in perspective and exploded urations of a fifth embodiment of a tensioning device appropriate for ion in a cable lifeline assembly according to the invention; Figure 17 is an ed perspective view of a second embodiment of an energy absorbing device fitted to the first mounting arrangement of the cable lifeline assembly of the embodiment of figure 1; Figure 18 is an enlarged perspective view of a third embodiment of an energy absorbing device fitted to the first mounting arrangement of the cable lifeline assembly of the embodiment of figure 1; Figure 19 is an enlarged ctive view of a fourth embodiment of an energy absorbing device fitted to the first mounting arrangement of the cable lifeline assembly of the embodiment of figure 1; Figure 20 is an enlarged perspective view of a second ment of a first mounting arrangement of a cable lifeline assembly according to the invention installed on an alternative structure at heights in the form of a pole ladder; Figure 21 is an enlarged perspective view of a third embodiment of a first mounting arrangement of a cable ne assembly according to the invention installed on the ative pole ladder; Figure 22 is an ed perspective view of a fourth embodiment of a first mounting arrangement of a cable ne assembly according to the invention installed on the alternative pole ladder.

Detailed Description As seen in figures 1 to 4, there is a cable lifeline assembly 10 of one embodiment of the invention installed on a structure at heights which in this case is a ladder 12. The ladder 12 in this example is a permanent ladder typically for ing a roof or other overhead structure.

The cable lifeline assembly 10 of figures 1A and 1B in a first aspect of the invention broadly comprises: 1. an energy absorbing device 14 adapted to mount to a first mounting arrangement 16 associated with the ladder 12; 2. a cable 18 at one end connected to the energy absorbing device 14, the cable 18 adapted to provide detachable coupling for a person 19 to arrest them in the event of a fall; 3. a second mounting arrangement 20 adapted to mount to the ladder 12; 4. a tensioning device 22 connected to an opposite end of the cable 18 and being associated with the second ng ement 20 for tensioning of the cable 18.

The person 19 exposed to a fall is typically wearing a harness (not shown) and is coupled to the cable 18 via a al e 21 which traverses the cable 18.

The harness is associated with a lanyard 23 or the like which is detachably attached to the al shuttle 21 via a karabiner or the like (not shown). In the event of a fall, the vertical shuttle stops the person’s progress and the energy absorbing device 14, under the dynamic force d on the cable 18 by the falling person 19, is plastically deformed. As best seen in figures 5A and 5B, the energy absorbing device 14 in this ment includes a pair of frangible elements 24a and 24b which are designed to fracture at a predetermined stress in the event of, and under the impact of, a fall. The frangible elements 24a/b are in this embodiment clearly visible so that on fracturing they visually indicate deployment of the energy absorbing device 14.

In a second aspect of the invention the cable lifeline assembly 10 of figures 1 to 4 does not extend to the cable 18. The cable lifeline assembly 10 of this embodiment of this second aspect generally comprises the energy absorbing device 14 and the tensioning device 22 together with the first and second mounting arrangements 16 and 20, tively, As seen in s 4A and 4B, the tensioning device 22 of this embodiment includes an actuator in the form of a threaded fastener 26 configured to threadably engage a corresponding threaded portion 28 of a second termination 29 at the opposite end of the cable 18. The threaded fastener is in this case an actuator nut 26 which on rotation in either a clockwise or anti-clockwise direction effects axial movement of the actuator nut 26 in a first direction for tensioning of the cable 18. In this embodiment the tensioning device 22 includes biasing means in the form of a compression spring 30 arranged to cooperate with the or nut 26 for controlling tensioning of the cable 18.

In the course of installing the cable lifeline assembly 10, the cable 18 is tensioned to a predetermined load depending on at least the following erations: 1. the likely dynamic force or impact loading of the cable 18 in the event of a fall; 2. operational requirements of the cable lifeline ly 10 ing displacement of the cable 18 from the cable guides for traversing of the associated shuttle (not shown); 3. stress characteristics of the selected energy absorbing device such as 14 and in particular the predetermined stress at which the frangible elements such as 24a/b fracture.

The tensioning device 22 of this embodiment provides effective tensioning of the cable 18 to the predetermined load. It will be understood that the predetermined load at which the cable is to be tensioned is acceptable within a range of appropriate loads. In this embodiment the actuator nut 26 gradually compresses the ssion spring 30 to achieve the predetermined tension or load within the cable 18. The actuator nut 26 bears against an intermediate washer 32 which contacts the compression spring 30 which is ed to be fully compressed at the predetermined load or tension in the cable 18. The spring 30 is compressed between a second bracket 33 of the second mounting arrangement 20 and the ediate washer 32 in the course of tensioning the cable 18 via rotation of the ion nut 26.

The spring 30 has characteristics including its physical dimensions and in particular the spring constant which determine that the predetermined load in the cable 18 is achieved on full compression of the spring 30. It is to be tood that full compression of the spring 30 is achieved when axial displacement of the spring 30 is negligible on continued rotation of the actuator nut 26 for axial movement in the first direction. It will be understood that the predetermined tension in the cable 18 is significantly less than the predetermined stress at which the ble elements such as 24a/b of the energy ing device 14 are designed to fracture. The tensioning device 22 includes a locking nut 35 and associated washer 37 ed to engage the threaded portion 28 of the second termination 29 on an opposite side of the second bracket 33. The locking nut 35 locks the second termination 29 and the associated cable 18 with the second bracket 33 once the predetermined load is achieved in the cable 18 via actuation of the tensioning device 22.

Returning to figures 2 and 3, the first mounting arrangement 16 is in the form of a first t ly adapted to mount to the ladder 12, the first t assembly 16 including a first bracket 34 mounted to an upper end of a first elongate member 36. The energy absorbing device 14 is suspended from the first bracket 34 and a lower end of the first member 36 is adapted to mount to the ladder 12. In this e the first bracket assembly 16 includes a pair of first clamping assemblies 38 and 40 dedicated to respective rungs 42 and 44 of the ladder 12. The clamping assemblies 38/40 in this case ably clamp the first member 36 to the ladder 12.

Figure 6A is an enlarged view of one embodiment of the ng assemblies 38 including a baseplate 46 and a pair of U-shaped bolts 48a and 48b. In this embodiment the U-bolts 48a/b engage one of the rungs such as 42 of the ladder 12 with the associated base plate 46 bearing against the first member 36 (see figure 2). The clamping assembly 38 also includes a pair of nuts such as 50a and 50b threadably engaging respective legs of the corresponding U-bolt 48a. In this case the pair of nuts 50a/b are locked er via safety wire 52a. The safety wire is in the form of seizing wire 52a which prevents rotation of the nuts 52a/b whereby breakage or distortion of the seizing wire 52a can be visually detected ing unlocking of the nuts 50a/b. In several variations, the nuts such as 50a/b may each be a locking-style nut or a nut locked with a thread-locking compound in which case the safety wire 52a is not required. In these variations, the nut may be marked to permit visual inspection to reveal ing of the nut. Figure 6B illustrates another embodiment of the clamping assembly 38 which is substantially cal to the preceding embodiment with the same reference numerals used. In this clamping assembly 38 the safety wires 52a/b associated with the nuts 50a/b of the preceding embodiment are replaced with indicator tabs such as 53c and 53d dedicated to respective of the nuts 50c and 50d. As illustrated the misalignment of indicator tabs 53c/d means visual inspection fails and es maintenance as d to indicator tabs 53a/b which remain aligned.

As seen in figure 3B, the energy absorbing device 14 is suspended from the first bracket 34 via a suspension bolt 54 and its ated pair of outer washers 56a and 56b together with nut 58 and associated spring washer 60. In this example the first bracket 34 includes a pair of spaced hanger members 62a and 62b between which the energy absorbing device 14 is mounted. The first bracket assembly 16 also includes a pair of protective and enlarged washers 64a and 64b located within the hanger members 62a/b on either side of the energy absorbing device 14. The energy absorbing device 14 is detachably connected to a first termination 65 at an upper end of the cable 18 via a clevis pin 66 and associated retaining clip 68.

As seen in figures 4A and 4B, the second mounting arrangement 20 of this embodiment includes a second member 70 to which the second t 33 is mounted to provide anchorage for the cable 18 via the tensioning device 22. The second bracket assembly 20 includes a pair of second clamping assemblies 82 and 84 dedicated to respective rungs 86 and 88 of the ladder 12. The clamping assemblies 86/88 are substantially cal to the first clamping assemblies 38/40 and operate to releasably clamp the second member 70 to the ladder 12. It should be understood that the locking arrangements of the first clamping assembly 38 from figures 6A and 6B are also applicable to the second clamping assembly 82.

As seen in figures 5A and 5B, the energy absorbing device 14 is elongate and es a deformable intermediate portion 90 formed continuous with and located between opposing upper and lower ng portions 92 and 94, respectively. The upper mounting portion 92 is in this embodiment connected to the first bracket 34 whereas the lower mounting portion 94 is attached to the first termination 65 of the cable 18. The energy absorbing device 14 is ntially symmetrical either side of its longitudinal axis and includes a pair of laterally disposed and plastically deformable members 96a and 96b. These deformable members 96 a/b are in this case tine-shaped and configured to distort or in this case elongate in the event of a fall. It will be understood that figure 5A depicts the energy absorbing device 14 in its “before fall” configuration without any distortion of the deformable serpentine members 96a/b s figure 5B depicts the energy absorbing device 14 in its “after fall” configuration with distortion or tion of the deformable serpentine members 96a/b.

The energy absorbing device 14 es a central member 98 d ntially between and temporarily connected to each of the pair of deformable members 96a/b via respective of the frangible elements 24a/b. The ble elements are configured on elongation of the pair of deformable s 96a/b to fracture providing visual indication of the deployment of the energy absorbing device 14 in its “after fall” configuration. The central member 98 of this example takes the form of an elongate post permanently connected to the lower mounting portion 94. It will be appreciated that the central post 98 is not permanently connected to the upper mounting portion 92 thereby permitting separation of the upper and lower mounting portions 92/94 on plastic deformation of the energy ing device 14 in the event of a fall.

Figures 7A and 7B to figures 11A and 11B illustrate variations of the energy absorbing device 14 of the preceding embodiment. It will be understood that the uppermost ration in each case shows the energy absorbing device in its “before fall” configuration whereas the lowermost illustration shows the energy absorbing device in its “after fall” configuration. For ease of reference and in order to avoid repetition, the same reference ls have been used for corresponding components of these alternative embodiments when compared to the preferred embodiment. The ative embodiments as seen in the corresponding figures include the ing ions from the preferred embodiment, noting that: 1. figures 7A and 7B include an additional or third frangible element at 24c d between the upper mounting portion 92 and the central member 98, the third frangible element 24c also ring on distortion or plastic deformation of the deformable members such as 96a/b; 2. figures 8A and 8B e an additional pair of frangible elements 24d and 24e temporarily connected between the upper end mounting portion 92 and the central member 98; 3. figures 9A and 9B include the pair of frangible elements 24a/b and third frangible element 24c of figures 7A/B together with a pair of visual elements 24f/g and 24h/i associated with respective of the pair of frangible elements 24a and 24b; 4. figures 10A and 10B are limited to the pair of additional frangible elements 24d/e of figures 8A/B but without any other frangible elements; . figures 11A and 11B include the pair of frangible elements 24a/b of the preferred embodiment (best seen in figures 5A/B) together with a visual indicator in the form of a pair of tinuous lines 100a and 100b associated with both the central member 98 and the pair of deformable members 96a/b.

Remaining at figures 11A/B, it can be seen that the discontinuous lines 100a/b are substantially aligned or collinear in the e fall” configuration of the energy absorbing device 14. On the other hand, in the event of a fall the energy absorbing device 14 in its “after fall” configuration results in misalignment of the pair of visual indicator line 100a/b clearly visually revealing deployment of the energy absorbing device 14. This means the energy absorbing device 14 including the visual indicator can be easily ted visually to reveal whether or not it has deployed.

For example, drones can be used for this visual inspection eliminating the need for inspectors to climb the ladder such as 12 or otherwise expose themselves to heights.

The alternative embodiments of figures 8A/B to 10A/B also orate visual indicators intended to visually identify deployment of the energy absorbing device 14. In each of these variations the visual indicator is associated with or formed by the nt frangible elements which define a recess ured to change shape on fracturing of the frangible elements. For example, in figures 8A/B and 10A/B the pair of additional frangible elements 24d/e in the “before fall” configuration represent a pair of triangles in an hourglass formation 99. On deployment of the energy absorbing device 14 in the “after fall” configuration, the hourglass form 99 is destroyed on fracturing of the frangible elements 24d/e. In the example of figures 9A/B, the frangible elements 24a/b and 24f to 24i in the “before fall” configuration form four (4) oval-shaped recesses such as 101a and 101b whereas in the “after fall” configuration these closed-recesses 101a/b are opened on fracturing and distortion of the nt frangible elements.

Figure 12 illustrates three adjacent cable guide assemblies 102a to 102c clamped to respective rungs 104a to 104c of the ladder 12. Each of the cable guide assemblies such as 102a includes a clamp subassembly 106a for detachable fitting to the respective rung 104a, and a cable guide element 108a mounted to the clamp subassembly 106a. The cable guide element 108a is constructed of a ently flexible material and includes a throat 110a for entry and retention of the cable 18.

The throat 110a is of a dimension ly less than the diameter of the cable 18 which requires resilient flexing of the guide element 108a for entry and removal of the cable 18. It can be seen that the mouth 110a of the guide element 108a is tapered inward to facilitate entry of the cable 18 into a cable e 112a formed by the guide element 108a and designed to retain the cable 18. Each of the guide elements such as 108a and 108b is angularly ced at 90 s ve to one another. This means sideways tion of the cable 18 from the guide element 108a ensures that it remains within the adjacent guide element 102b. Likewise, forward retraction of the cable 18 from the guide element 102b only effects removal from the central guide 102b with the cable 18 retained in the upper and lower guide elements 108a and 108c. It will be appreciated that this retraction of the cable 18 is required in the course of safe traversing of the associated vertical shuttle (not shown) along the length of the cable 18.

Figures 13A to 13B to figures 16A and 16B illustrates variations on the tensioning device 22 of the preferred embodiment. For ease of reference and in order to avoid repetition, the same reference ls have been used for these alternative embodiments compared to corresponding components of the preferred embodiment.

It can be seen that figures 13A to 15A depict the tensioning device in its assembled configuration with the left hand representation being a side elevational view and the right hand entation being a front ional view. Figures 13B to 15B illustrate these variations on the tensioning device 22 in an exploded view taken in side elevation. Figures 16A and 16B depart from this format with figure 16A showing the tensioning device 11 fitted to the ladder 12 in perspective view with figure 16B g components of the tensioning device in side elevation and exploded.

Figures 13A and 13B illustrate a second embodiment of a tensioning device for inclusion in the cable lifeline assembly 10 of the ing embodiment. In a similar manner to the preferred embodiment, this tensioning device 22 is designed to cooperate with the second termination 29 crimped for connection with the associated cable 18 (not shown). In addition to the actuator nut 26, compression spring 30 and intermediate washer 32, this second embodiment es a housing 110 containing the compression spring 30, and a plunger 112 configured to cooperate with the actuator nut 26 and the compression spring 30 for ssion of said spring on on of the actuator nut 26. In this example the r 112 is at least in part located within the g 110 and includes a guide 114 which moves axially together with the plunger 112 on rotation of the actuator nut 26. The guide 114 cooperates with an indicator scale 116 on the housing 110 to indicate the relative position of the plunger 112 within the housing 110 and thus the extent of axial compression of the spring 30. The housing 110 includes an axially oriented slot 118 with which the guide 114 is aligned during axial nt of its associated plunger 112. The indicator scale 116 is located ide the slot 118 for visual alignment of the guide 114 with the indicator scale 116 of the housing 110. The indicator scale 116 is calibrated in conjunction with the known characteristics of the compression spring 30 so that the predetermined load in the cable 18 can be achieved by rotation of the actuator nut 26. The tensioning device 22 of this second embodiment otherwise includes a boot 120 located around the second termination 29 and bearing upon the second bracket 33 for sealing of the enclosed components of the tensioning device 22.

Figures 14A and 14B illustrate a third embodiment of the tensioning device 22. This embodiment is substantially identical to the second embodiment of s 13A/13B except that the cable 18 is connected to the second termination 29 via a swageless subassembly 122. The swageless subassembly 122 of this example includes a ess housing 124 containing a compressible collet 126 which cooperates with an actuator ring 128 and associated nut 130. The collet 126 is designed to grip an end of the cable 18 within the swageless housing 124 on rotation of the actuator nut 130. The swageless subassembly 122 also includes a g nut 132 ed to frictionally engage the actuator nut 130 and seat on the boot 120.

Otherwise, the tensioning device 22 of this third embodiment operates in an identical manner to the second embodiment.

Figures 15A and 15B rate a fourth embodiment of the tensioning device 22 which in this case is associated with the cable 18 by clamping of the cable 18 to the second termination 29 via one or more grips such as 133a and 133b. This fourth embodiment is otherwise substantially identical to the second and third embodiments with the ion of the following components: 1. an intermediate bush 134 which resides within the plunger 112 for abutment with the intermediate washer 32 against which the actuator nut 26 bears; 2. a locking nut 136 designed to lock against the actuator nut 26 when the predetermined load in the cable 18 is achieved.

Figures 16A and 16B rate a fifth embodiment of the tensioning device 22 which in a similar manner to the fourth embodiment is secured to the cable 18 via appropriate grips such as 133a and 133b. The tensioning device 22 is otherwise of a ntially identical construction to the third embodiment of figures 14A/B. Once again, the tensioning device 22 is designed and effectively calibrated whereby the predetermined load in the cable 18 can be achieved relying on the guide 114 and indicator 116.

Figures 17 to 19 illustrate variations on the cable lifeline assembly 10 of the preferred embodiment. For ease of reference and in order to avoid repetition, the same reference numerals have been used for these alternative embodiments compared to corresponding components of the preferred embodiment.

Figure 17 depicts an alternative embodiment including a secondary anchor 140 formed al with the energy absorbing device 14 for detachable tion to a lanyard or the like associated with a person working at heights. In this example the secondary anchor 140 is in the form of a lug 142 extending from the upper portion 92 of the energy absorbing device 14. The lug 142 es an enlarged aperture 144 to which a karabiner or other coupling fitting is detachably secured. It will be iated that location of the secondary anchor 140 at the upper portion 92 of the energy absorbing device 14 isolates it from the able and frangible components of the device 14. This means that any load imparted on the secondary anchor 140 will not deploy the device 14 which will remain in its “before fall” configuration.

Figures 18 and 19 depict alternative embodiments with secondary anchors in each case mounted to the first t assembly 16. In these examples the ary anchors 140 are in the form of eyebolts 150. In figure 18, the eyebolt 150 es the bolt 54 of the preferred embodiment of figures 3A/B in bridging the pair of hangers 62a/b in suspending the energy absorbing device 14. In figure 19, the t 150 is screwed or otherwise mounted at a head of the first member 36 of the first bracket assembly 16. In these other embodiments, the secondary anchor 140 functions entirely independent of the energy absorbing device 14. s 20 to 22 show installation of the energy absorbing device 14 on an alternative structure at heights in the form of a pole ladder 160. In these variations of the cable ne assembly 10 of the preferred embodiment, the first mounting arrangement or bracket assembly 16 departs from the preceding embodiment. In particular it can be seen from figures 20 to 22 that the first bracket assembly 16 of these variations include: 1. in the second ment of figure 20, the first mounting ement 16, a pair of clamp arrangements 162 and 164 configured to clamp about a main pole 166 of the pole ladder 160, the pair of clamp arrangements 162/164 sharing a common hanger 168 from which the energy absorbing device 14 is suspended; 2. in the third embodiment of figure 21, the first mounting ement 16 having a vertical rail 170 fastened to the main pole 166 with the pair of hanger members 62a/b ted to the common rail 170, the energy absorbing device 14 being suspended from between the hanger members 62a/b; 3. in the fourth embodiment of figure 22, a single clamp arrangement 180 configured to clamp about the main pole 166, a hanger 182 from which the energy absorbing device 14 is suspended, and a strut 184 connected between the pole 166 and the hanger 182.

Now that a preferred embodiment of the t invention has been described, it will be apparent to those skilled in the art that the cable lifeline assembly has at least the ing advantages: 1. the assembly includes an energy absorbing device which in the event of a fall can be visually inspected to clearly indicate deployment of the device; 2. the energy absorbing device incorporated in the assembly in the event of a fall reduces forces on the associated structure and person; 3. the tensioning device provides an effective means for tensioning the cable to a ermined load; 4. the cable lifeline assembly can be installed on a ladder or other structure at heights with relative ease.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described.

For example, the cable of the broadest aspects of the invention is intended to encompass a range of elongate and flexible members ing but not limited to wire, rope, composite products, and combinations f. Although the described embodiments are in the context of permanent s it is to be understood that the invention extends to le or temporary ladders as well as other structures at heights, the invention also has application in horizontal static lines installed on a roof and other overhead structures. The energy absorbing device may vary icantly from the embodiment described and illustrated provided in the event of a fall it is capable of plastic deformation fracturing one or more ble elements which visually indicate deployment of the energy absorbing device.

All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the foregoing description.

Claims (28)

Claims 1.

1. A cable lifeline assembly sing: an energy absorbing device including a frangible t, said energy absorbing device adapted to mount to a first mounting arrangement associated with a structure at heights; a cable at one end connected to the energy absorbing device, the cable adapted to provide detachable coupling for a person to arrest them in the event of a fall; a tensioning device associated with a second mounting arrangement adapted to mount to the structure, said tensioning device ted to an opposite end of the cable and ed for ning of the cable whereby in the event of a fall the energy absorbing device is, under the additional force exerted on the cable by the person, plastically deformed thereby fracturing the frangible element which visually indicates deployment of said energy absorbing device.

2. A cable lifeline assembly comprising: a first mounting arrangement associated with a structure at heights; an energy absorbing device including a frangible t, said energy absorbing device mounted to the first mounting arrangement and adapted to connect to a cable which es detachable coupling for a person to arrest them in the event of a fall; a second mounting arrangement adapted to mount to the structure; a tensioning device associated with the second mount arrangement and adapted to connect to an opposite end of the cable for tensioning of the cable whereby in the event of a fall the energy absorbing device is, under the onal force exerted on the cable by the person, plastically deformed thereby fracturing the frangible element which visually tes deployment of said energy absorbing device.

3. A cable lifeline assembly as claimed in either of claims 1 or 2 wherein the tensioning device includes an actuator configured to engage the opposite end of the cable for tensioning it on nt of the actuator in a first direction.

4. A cable lifeline assembly as d in claim 3 wherein the tensioning device includes biasing means arranged to cooperate with the actuator for controlling tensioning of the cable via the biasing means on movement of the or in the first direction.

5. A cable lifeline assembly as claimed in claim 4 wherein the tensioning device also includes a housing containing the biasing means in the form of a compression spring designed to control ning of the cable.

6. A cable lifeline assembly as claimed in claim 5 wherein the tensioning device further includes a plunger configured to cooperate with the actuator and the compression spring for compression of said spring on movement of the actuator in the first direction.

7. A cable lifeline assembly as claimed in claim 6 wherein the plunger is at least in part located within the housing and includes a guide which cooperates with an tor associated with the housing to indicate the relative position of the plunger within the housing under the influence of the actuator being moved in the first direction, the guide and the indicator thereby indicating the tension in the cable.

8. A cable lifeline ly as claimed in any one of claims 3 to 7 n the actuator includes a ed fastener configured to threadably engage the opposite end of the cable whereby rotation of the threaded fastener in either a ise or anti-clockwise direction effects its movement in the first direction for tensioning of the cable.

9. A cable lifeline assembly as claimed in claim 8 wherein the threaded fastener is in the form of an actuator nut which threadably engages a corresponding threaded portion at the opposite end of the cable.

10. A cable lifeline assembly as claimed in any one of the preceding claims wherein the first mounting arrangement includes a first bracket assembly adapted to mount to the structure at heights in the form of a ladder.

11. A cable ne assembly as d in claim 10 wherein the first bracket assembly es a first t from which the energy absorbing device is suspended, and a first member at an upper end mounted to the first bracket and at or nt a lower end adapted to mount to the ladder.

12. A cable lifeline assembly as claimed in either of claims 10 or 11 n the first mounting arrangement also includes a first clamping assembly configured to releasably clamp the first member to the ladder.

13. A cable lifeline assembly as claimed in either of claims 10 or 11 wherein the first t is secured directly to the ladder.

14. A cable ne assembly as claimed in any one of claims 10 to 13 wherein the second mounting arrangement includes a second bracket assembly adapted to mount to the ladder.

15. A cable lifeline assembly as claimed in claim 14 wherein the second bracket assembly includes a second member associated with the tensioning device, and a second clamping assembly configured to ably clamp the second member to the ladder.

16. A cable lifeline assembly as claimed in claim 15 wherein the second bracket ly includes a second bracket mounted to the second member, the second bracket configured to provide anchorage for the cable via the tensioning device.

17. A cable lifeline assembly as claimed in any one of the preceding claims wherein the energy absorbing device is elongate and includes a deformable intermediate portion formed continuous with and located between opposing end mounting portions ted to respective of the first mounting arrangement and the cable.

18. A cable lifeline assembly as claimed in claim 17 wherein the ediate portion includes a pair of laterally disposed and plastically deformable s, said pair of deformable members in the event of a fall being configured to t for elongation of said energy absorbing device.

19. A cable lifeline assembly as claimed in either of claims 17 or 18 wherein the energy absorbing device includes a central member located ntially between and connected to at least one of the pair of deformable members via the frangible element which is configured on elongation of the pair of deformable members to fracture thereby providing visual indication of the deployment of said energy absorbing device.

20. A cable ne assembly as claimed in claim 19 wherein the central member is ted to either of the opposing end mounting portions via the frangible element which is configured to fracture on elongation of the pair of members.

21. A cable lifeline assembly as claimed in either of claims 19 or 20 wherein the energy absorbing device includes a visual indicator associated with both the central member and at least one of the pair of deformable members whereby tion of the deformable members effects cement of the l member relative to said at least one of the deformable members thus ing visual tion of the deployment of said energy absorbing device via the visual indicator.

22. A cable lifeline assembly as claimed in claim 21 wherein the visual indicator includes at least one indicator line which without distortion of the deformable members is substantially aligned s in the event of a fall the indicator line is misaligned thereby visually revealing deployment of said energy absorbing device.

23. A cable ne assembly as claimed in claim 21 wherein the visual indicator is at least in part associated with the frangible t which on distortion of the deformable members fractures providing visual indication of deployment of the energy absorbing device.

24. A cable lifeline ly as claimed in claim 23 wherein the frangible element is one of a plurality of frangible elements which at least in part define a recess configured to change shape on fracture of the frangible element thereby providing visual indication of the deployment of said energy absorbing device.

25. A cable lifeline assembly as claimed in any one of claims 21 to 24 wherein the energy absorbing device including the visual indicator is ured for visual inspection to reveal whether or not it has deployed.

26. A cable lifeline assembly as claimed in any one of the preceding claims also comprising a secondary anchor for detachable connection to a lanyard or the like associated with the person.

27. A cable lifeline assembly as claimed in claim 26 wherein the secondary anchor is formed integral with the energy absorbing device at the end mounting portion mounted to the first mounting arrangement.

28. A cable ne assembly as claimed in claim 26 (when it s on claim 11) wherein the secondary anchor is mounted to either the first member or the first bracket of the first bracket assembly.