[001] Various embodiments relate generally to fall-protection safety devices, and more specifically to anchor systems for personal fail-protection safety harnesses.

BACKGROUND

[002] Fail-protection safety equipment is widely used in situations where persons work or play at dangerous heights. Often a worker may wear a fall-protection safety harness, which provides connection structures to which a lanyard or cable may be attached. The lanyard or cable may then be attached to a fixed anchor, so that in the event of a fall, the worker will be tethered to a fixed structure. For example, a worker who is working on a high-rise building may be located on a floor that is many stories above ground level. And during construction, the walls are often not in place while workers are performing needed construction operations. For example, the concrete floors are frequently poured before walls and windows are installed. The workers who are assisting the concrete pour must necessarily put work where there is a danger of falling. These workers may attach a lanyard to a fixture located nearby their working location.

SUMMARY

[003] Apparatus and associated methods relate to a. spooled cable system for use as a horizontal lifeline, the system including a deforming member connecting a cable spool to a locking cable tightening member, wherein the deforming member torsionally deforms when a predetermined torque between the spool and the tightening member is exceeded while the cable tightening member is locked. In an illustrative example, the deforming member may provide a predetermined torsional resistance during a fall event. Various embodiments may include a torsion reference to indicate the amount of torsional deformation that the deforming member has undergone. A torsion indicator may provide visual indication, for example, of an amount of deformation of the deforming member. In an exemplar)' embodiment, the spoofed cable system may advantageously provide a substantially uniform force profile to a falling worker during a fail event. [004] Various embodiments may achieve one or more advantages. For example, some embodiments may provide substantially consistent force profiles independent of environmental changes. For example, the force profile may be substantially temperature insensitive. In some embodiments, the force profile may be substantially moisture insensitive. The force profile may remain constant even as a torsion member ages, in some examples. Some embodiments may provide a substantially uniform force profile throughout the duration of a fall event. For example, an initial elevated force may not be required, such as is frequently required to overcome static resistance of frictional braking members,

[005] Various embodiments may permit ease of manufacture, as critical dimensions may be relatively large. In some embodiments, the variations of the force profiles due to manufacturing tolerances may be relatively easily controlled. In some embodiments, the torsional deforming member may be replaceably after a fall event. In some embodiments, receriificaiion of the system may be relatively easy, as only the torsional deforming member may require replacement after a fall event. In some embodiments, a visual indicator of deformation may permit quick verification of the system's integrity. In some embodiments a visual indicator of cable tension may permit the quick setup of a horizontal life line.

[0061 In an exemplary embodiment, a single horizontal lifeline system may simultaneously couple to one or more workers. In such an embodiment, the lifeline system may provide multiple workers with an anchor. In some embodiments workers may not need to unconnected and reconnect as the worker moves along the length of the horizontal lifeline. In such a scenario, the worker may not need to expose himself/herself to even a momentary unprotected risk. In some embodiments, a fallen worker may be present a safe force profile during a fall event. Such a force profile may be "jerk-free" and may prevent physical damage to the fallen worker. Various embodiments may present a force profile that has been designed for the weight of a worker or a group of workers, for example. In some embodiments the force profile may be designed to change the force presentation to the worker as a function of the amoun t of cable released to the worker during the fall event.

[007] The details of various embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[008] FIG. 1 depicts an exemplar}? horizontal lifeline system with a torsional deforming member employed in a high-rise building construction site.

[0091 FIGS. 2A-2B depict a plan view and side cross-sectional view of an exemplary horizontal lifeline system with a torsional deforming member.

[0010] FIGS. 3A-3C depict an exemplary torsional deforming member before and after deformation ,

[001 1] FIGS. 4A-4B depict an exemplary torsional deforming member with both inner and outer torsional deformation elements.

[0012] FIGS. 5A-5C depict an exemplary torsional deforming member exhibiting dimensional changes resulting from torsional deformation.

[0013] FIGS. 6A-6B depict an exemplar}' rotatable cable spooling members with a torsion induced frictional brake.

[0014] FIGS. 7A-7B depict exemplary rotatable cable spooling members with different spool diameters.

[0015] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0016] To aid understanding, this document is organized as follows. First, an exemplary application of a horizontal lifeline system is briefly introduced with reference to FIG, I . Second, with reference to FIGS. 2A-3B, the discussion turns to an exemplary embodiment that illustrates some of the functional members of an exemplary horizontal lifeline system. Then, with reference to FIGS. 4A-4C a multi-element torsional deformation member will be described. Then, with reference to FIGS. 5A-6B, exemplary rotatable cable spooling members that employ frictional braking is described. Finally, with reference to FIGS. 7A-7B, some design considerations will be discussed.

[0017] FIG. 1 depicts an exemplary horizontal lifeline system with a torsional deforming member employed in a high-rise building construction site. In this figure, a construction site 100 shows a building 105. The building 105 has vertical girders 110. Attached to the girders 1 10 is an exemplary horizontal lifeline system 1 15. The horizontal lifeline system 1 15 includes has a cable 120 which is stretched between one of the girders 110 and an enclosure 125. The enclosure 125 is shown attached to the other girder 1 10 via a n strap 130. A worker 135 is wearing a fall -protection safety harness 140. A lanyard 145 is attached to the fall-protection safety harness 140 and to the horizontal cable 120. The lanyard 145 is attached to the horizontal cable 120 via a slidable connecting ring 150. The worker 135 thus may be free to move along the length of the cable 120 while remaining connected thereto. The enclosure 125 contains a torsional deforming member 155 on an axis of rotation. The torsional deforming member 155 may deform if a predetermined torque is applied across two ends of the member. If, for example, the worker 135 were to fall from the building 105, a force may be exerted upon the cable 120 which may be converted to a tensile force on the cable 120. The tensile force on the cable 120 may then be converted to a torque on a cable spool. When the torque exceeds a predetermined threshold, the torsion member 55 may deform to soften the fall of the worker 135.

[0018] FIGS. 2A-2B depict a plan view and side cross-sectional view of an exemplary horizontal lifeline system with a torsional deforming member. FIG. 2A depicts an exemplary horizontal lifeline system 200 in plan view. The lifeline system 200 includes a drum 205 upon which a cable 210 may be spooled. The drum 205 is coupled to a torsional deformation member 215 and to a ring gear 220. The ring gear 220, the torsional deformation member 215 and the cable drum 205 all rotate about a central axis 225. The lifeline system 2,00 may be connected to two horizontal anchors via two anchor connections, an anchorage eye 230 on one side and carabiner 235, which is attached to a free end 240 of the cable 210. The user may first attache the anchorage eye 230 to a vertical beam, for example. In an exemplary embodiment, the user may wrap a strap around a beam, for example, and connect both ends of the strap to the anchorage via a carabiner, for example. The user may unlock a rotatable drum assembly (which includes the drum 205, the torsional deformation member 215 and the ring gear 220) by use of a locking mechanism 245

(depicted in FIG. 2B). The cable 210 may then be freely extracted from the spool and pulled to a second anchor point. The carabiner 235 attached to the cable in the depicted

embodiment may then be secured to the anchor point. After securing both sides of the lifeline system 200 to anchor points, the system may be tensioned. In the depicted embodiment, a. hand crank 250 is coupled to the ring gear 220 so as to permit a user to retract the cable 210 and/or to put the cable 210 into tension.

[00191 In FIG. 2B the lifeline system 200 is depicted in a side cross-sectional view.

In this view, the cable 210 is shown spooled onto the drum 205. In this exemplary embodiment, the torsional deforming member 215 is shown connected to the ring gear 220 on a. ring gear end 255 , and to the drum 205 on a gear end 260 of the torsional deforming member 215. The entire assembly (of torsional deforming member, drum, and ring gear may rotate on a shared axis of rotation 225. Irs some embodiments bearings located in a housing 265 may facilitate this rotation. In an exemplary embodiment, bushings located in the housing 265 may facilitate the rotation.

[0020] The ring gear 220 may be locked by the user using the locking mechanism

240, for example. When the ring gear 220 is locked, the cable 210 may not be unspooled freely from the drum 205. Should a fail event occur, a tensile force may be imparted to the cable 210. This tensile force may be translated into a torque on the drum 205 as the cable 210 is being forcible pulled by the weight of the fallen worker. If this torque exceeds a predetermined threshold, the torsional deforming member 215 may deform, which may permit the drum 205 to rotate, e en while the ring gear 220 remains locked. The predetermined threshold of torque needed to begin deformation may be established using many of the design degrees of freedom in the lifeline system 200. In. some embodiments, changing the diameter of the torsional deforming member 215 may change the torque needed for deformation. In an exemplary embodiment, the composition of the torsional deforming member 215 may affect the torque needed for deformation. In some embodiments, a wall thickness of the torsional deforming member 215 may affect the torque requirement for deformation. In some embodiments, the diameter of a spooling surface of the drum 205 may affect the torque requirement for deformation.

[0021] FIGS. 3A-3B depict an exemplary torsional deforming member before and after deformation. In the FIG. 3A embodiment, an exemplary torsional deforming member 300 is shown before deformation. The torsional deformation member is depicted having two connection flanges 305, 310, one on each end of a longitudinal dimension 315. One of the flanges (e.g. 305) may be used to connect to a ring gear, for example. The other flange (e.g. 310) may be used to connect to a. cable drum, for example. In the depicted embodiment, the two flanges 305, 310 are symmetric with respect to each other. In some embodiments, the two flanges may be different, one from another. In various embodiments, various connecting methods may be used. For example, bolts may be used to connect the torsional deformation member 300 to the connecting objects on either side of the member 300. In an exemplar)' embodiment, the torsional deformation member .300 may be riveted on each end. In an exemplary embodiment, pins may connect the torsional deformation member to the connecting objects on one side or the other, for example. In some embodiments, screws may be used for connection.

[00221 The torsional deformation member 300 depicted in FIG. 3A is again depicted in FIG. 3B, but after being deformed. In FIG. 3B, the deformed member 32,0 shows the member having striations 325 that may mark the deformed member 320. In the depicted embodiment, the deformation may have been the result of rotating a top flange 330 with respect to a bottom flange 335. If, for example, the top flange 325 has been rotated a half rotation with respect to the bottom flange, the body of the torsional deformation member may appear as in FIG. 3B. In some embodiments, the rotational deformation member32() may be designed to permit a deforming rotation of more than half a rotation. In various embodiments, the torsional deforming member 320 may be designed to rotate (0.25, 0.5 0.75, 1.25, 2, or more) rotations.

[0023] FIGS. 4A-4C depict an exemplary torsional deforming member with both inner and outer torsional deformation elements. In the FIGS. 4A-4B depictions, an exemplary two-element torsional deformation member 400 is depicted. The torsional deformation member 400 is shown having an inside deformation element 405 and an outside deformation member 410. The outside deformation member 410 has a top end 415 and a bottom end 420 as depicted in the figures. The inside deformation member 405 also has a top end 425 and a bottom end (obscured by the outside deformation member in the figures. The top end 415 of the outside deformation element 410 may be rigidly coupled to the top end 425 of the inside deformation element 405 in some embodiments. The bottom end 42.0 of the outside deformation element 410 may be rigidly coupled to the bottom end of the inside deformation element 405 in some embodiments. Each deformation element 405, 410 may deform if the torque presented between the tops 415, 425 and bottoms 420 exceed a pred etermin ed thres ol d .

[0024] In various embodiments, the two deformation elements 405, 410 may not be rigidly coupled (either at their tops or at their bottoms or both). FIG. 4C depicts a plan view of a flange 430 that has an aperture 435 in which is a square body 440 of an inside deformation element 405. The square body 440 may freely rotate within the aperture 435 for a predetermined rotation before engaging the flange 430. In the depicted embodiment, the square body 435 may rotate one quarter of a rotation before engaging the flange 430. Using such a mechanism, any deformation of the torsional deforming member 400 may be constrained to deformation of the outside element 410 for the first quarter rotation. Then the inside deformation element 405 may begin deformation when rotation exceeds on quarter of a rotation. The torque profile as a function of rotation may be predetermined using such mechanisms. In some embodiments, the inside element may be coupled to the outside element for during the initial deformation, and may disengage from the outside member when a predetermined amount of deformation has occurred. For example, a square aperture in the flange may engage a square body 440 of an inside deformation element 405. A longitudinal dimension of the inside deformation element 405 may decrease when deformation occurs. When a. predetermined amount of deformation has occurred, the longitudinal dimension may be too short for the square body 440 to remain engaged with the square aperture of the flange. In such an embodiment, the torque required for deformation may be initially larger than that required when the inside deformation element 405 is not longer engaged to the flange. Using such techniques, the torque profile of a. fall event may be determined. FIG. 4B depicts and exemplary torsional deformation member 445 after deformation has occurred.

[0025] FIGS, 5A-5C depict an exemplar}? torsional deforming member exhibiting dimensional changes resulting from torsional deformation. In the figures, an exemplary torsional deformation member 500 is shown in stages of deformation. In the depicted embodiment, the torsional deformation member 500 is depicted before deformation 505, after some deformation 510 and after even more deformation 515. The exemplary torsional deformation member has a longitudinal dimension that decreases after deformation. A longitudinal dimension 520 of the un deformed member 505 may be larger than a longitudinal dimension 525 of the somewhat deformed member 510, And a longitudinal dimension 525 of the somewhat deformed member 510 may be larger than a longitudinal dimension 530 of the more deformed member 515. Various embodiments may be designed so as not to permit longitudinal contraction during deformation. In the depicted embodiment longitudinal contraction during deformation has been permitted. In some embodiments, this longitudinal contraction may be used to engage a frictional brake after a predetermined amount of deformation has occurred, for example.

[0026] FIGS, 6A-6B depict an exemplar}? rotatable cable spooling member with a torsion induced frictional brake. In these depictions, an exemplary rotatable cable spooling member 600 includes a tensioning disk 605, a cable spool 610, and a torsional deforming member 615. The torsional deforming member 615 has a tensioning end 620 and a spooling end 625. The tensioning disk 605 is affixed to the tensioning end 620 of the torsional deforming member 620. The cable spool 610 is affixed to the spooling end 625 of the torsional deforming member 615. In FIG. 6A, the rotatable cable spooling member 600 is depicted before deformation of the torsional deformation member 615 has occurred. A lateral dimension 630 of the rotatable cable spooling member 600 is depicted. Also depicted is a gap dimension 635 between an inside surface 640 of the tensioning member 605 and a braking surface 645 of the cable spool 610. In FIG . 6B, the rotatable cable spooling member 600 is depicted after deformation of the torsional deformation member 650. In FIG. 6B, a lateral dimension 655 of the rotatable cable spooling member 600 is smaller than the lateral dimension 630 before deformation. Note that the gap dimension 635 that existed before deformation has disappeared. Further deforming rotation may require an additional torque as frictional braking may occur on friction surfaces 660.

[0027] FIGS. 7A-7B depict exemplary horizontal lifeline systems with different spool diameters. FIG. 7A depicts an exemplary rotatable cable spooling member 700 having a cable spool 705 onto which a cable 710 is spooled. The cable spool 705 has a spooling surface 715 that is substantially axially symmetric about an axis 720. The cable spooling member has an interior cavity 725 within which resides an exemplary torsional deformation member 730. In some embodiments, the torsional deformation member 720 may be substantially axially symmetric about the axis of symmetry 720. The cable spooling surface 715 is depicted having a diameter 755. In FIG. 7B, an exemplary rotatable cable spooling member 735 is depicted. The FIG. 7B embodiment has a cable spool 740 that has a smaller diameter 745 cable spooling surface 750 than that of the FIG. 7A embodiment. The diameter of the cable spooling surface 715 affects the predetermined tensile force required for deformation of the torsional deformation member 730. The smaller diameter 745 spooling surface 750 may translate a tensile force of the cable 710 to a smaller torque upon the torsional deformation member 730 than a larger diameter 745 spooling surface 715, for example.

[0028] Although various embodiments have been described with reference to the

Figures, other embodiments are possible. For example, in various embodiments the torsional deforming member may be made of ferrous materials. In an exemplary embodiment, the torsional deforming member may be made of steel, for example. In some embodiments the torsional deforming member may be made of syn thetic material. In an exemplary embodiment, the horizontal lifeline system may have a torsion bar indicator. Such an indicator may provide a visual indication of the amount of deformation that has occurred in the torsional deformation member. In some embodiments a reference mark on the tensioning end and a reference mark on the spooling end of the torsional deformation member may align when no deformation has occurred.

[0029] In some embodiments a torsional deformation member may include two or more torsional deformation elements. In some embodiments, these elements may work in conjunction throughout a fall event. In some embodiments, one or more of the deformation elements may work only during a portion of a fall event. For example, in some

embodiments a torsional deformation element may begin to deform only after some deformation of other elements have caused a predetermined amount of deformation to those elements. In some embodiments, a torsional deformation element may cease to be engaged and cease to deform after a predetermined level of deformation as already occurred. In some embodiments, torsional deformation may be used in conjunction with frietional braking. In an exemplary embodiment, frietional braking may begin after a predetermined amount of deformation has occurred. In an exemplary embodiment, friction braking may cease after a. predetermined amount of deformation has occurred.

[0030] In one exemplary aspect, a spooled-eable system may include a cable having a spool end and a free end. In an illustrative example, the spooled-eable system may have an enclosure having a fixed-attachment end and a cable-delivery end, the fixed-attachment end may have a mounting aperture configured to receive a carabiner and the a cable-delivery end may have a cable-delivery opening providing the free end of the cable to extend therethrough to an exterior of the enclosure while the spool end of the cable remains in an interior of the enclosure. The spooled-eable system may include a rotatable cable-spooling member to which may be attached the spool end of the cab le, wherein the rotatable cable-spooling member may be rotatably coupled to and within the enclosure. In some embodiments, the rotatable cable-spooling member may include a cable spool having an exterior cable- spooling surface and an interior cavity, wherein both the exterior cable-spooling surface and the interior cavity may be substantially axially symmetric about an axis of rotation. In an illustrative embodiment, the rotatable cable-spooling member may include a torsional deforming member having a tensioning end and a spooling end that is repiaceabiy coupled to the cable spool, wherein the torsional deforming member may be located substantially within the interior cavity and may be substantially axially symmetric about the axis of rotation. In some embodiments, the rotatable cable-spooling member may include a tensioning disk removably coupled to the tensioning end of the torsional deforming member, wherein the tensioning disk may have a. locked state and a free state, wherein when in the locked state, the tensioning disk may not rotate in response to pulling on the tree end of the cable, and wherein when in the free state, the tensioning disk may rotate in response to pulling on the free end of the cable. In some embodiments, if a torque about the axis of rotation between the cable spool and the tensioning disk is less than a. predetermined threshold, an angular rotation of the cable spool may be substantially equal to an angular rotation of the tensioning disk. In some embodiments if a torque about the axis of rotation between the cable spool and the tensioning disk exceeds the predetermined threshold, the torsional deforming member may deform and the angular rotation of the cable spool may be not equal to the angular rotation of the tensioning disk.

[0031] In another exemplary aspect, a spooled cable system may include a torsional deforming member having a central longitudinal axis, a spool end and a tensioning end. In an illustrative embodiment, the spooled cable system may include a cable spool rigidly coupled to the spool end of the torsional deforming member; wherein the cabl e spool may have a cylindrical cable spooling surface having a central axis collinear with the central longitudinal axis of the torsional deforming member. In some embodiments, the spooled cable system may include a roiatable tensioning disk rigidly coupled to the tensioning end of the torsional deforming member, wherein the rotatable tensioning disk may have an axis of rotation that is collinear with the central longitudinal axis of the torsional deforming member. I an illustrative example, if a torsion about the longitudinal axis between the cable spool and the tensioning disk is less than a predetermined threshold, an angular rotation of the cable spool may be substantially equal to an angular rotation of the tensioning disk. In an exemplary embodiment, if the torsion about the longitudinal axis between the cable spool and the tensioning disk exceeds the predetermined threshold, the torsional deforming member may deform and the angular rotation of the cable spool may be not equal to the angular rotation of the tensioning disk.

[0032] In another exemplary aspect, a spooled cable system may include a cable having a spoof end and a free end. In an illustrative example, the spooled cable system may include a cable spool to which is attached the spool end of the cable, wherein the cable spool may have a cylindrical cable spooling surface having a central axis. In some embodiments, the spooled cable system may include a rotatable tensioning disk having an axis of rotation that is collinear with the central axis of the cable spool. In various embodiments the spooled cable system may include means for differentiating the angular displacement of the cable spool and the rotatable tensioning disk in response to a tensile force of the cable. In some embodiments the differentiating means may include a deforming member coupled to both the cable spool and the rotatable tensioning disk. An example of such a differentiating means may be a torsional deforming member 300 as depicted in FIG. 3 . In some embodiments the differentiating means include a plurality of deforming elements. An example of such a differentiating means may be a multi-element deforming member 400 as depicted in FIG. 4A. An example of such a frictional brake may be the frictional surface 660 as depicted in FIG. 6B. In various embodiments, the differentiating means may include a. frictional brake. In an exemplary embodiment, the differentiating means may result in a non-zero angular displacement of the cable spool and the rotatable tensioning disk when the tensile force is greater than a predetermined threshold.

[0033] A number of implementations have been described. Nevertheless, it will be understood that various modification may be made. For example, advantageous results may be achieved if the steps of the disclosed techniques were performed in a different sequence, or if components of the disclosed systems were combined in a different manner, or if the components were supplemented with other components. Accordingly, other

implementations are contemplated.