Patent Publication Number: US-9427608-B2

Title: Self-retracting lifeline connecting system

Description:
TECHNICAL FIELD 
     Various embodiments relate generally to fall-protection systems. 
     BACKGROUND 
     Fall-protection safety harnesses are widely used in today&#39;s industrial world. Many occupations require workers to operate at great heights. These workers perform functions demanded by our modern world. Some examples of such occupations include bridge inspectors, high-rise construction operators, skyscraper window washers, etc. Individuals who work in such occupations require safety measures that are robust. But the safety equipment that is necessary must also permit the workers to accomplish the tasks at hand. It would be impractical, for example, if the safety measures were robust, but the safety equipment which accomplishes that measure of safety were so heavy as to render the worker immobile. 
     Companies who employ individuals to work at dangerous heights also have a concern for their well-trained employees. Such companies truly desire their employees to use the appropriate safety products, and to use them correctly. Thus, companies desire to use equipment that is easy to employ, and comfortable to wear. The easier such equipment is to use, the more likely the employee will use it properly. Furthermore, the more comfortable such equipment is to wear, the more likely an employee will wear it. Finally, if safety equipment is made to be easy to use, it becomes unlikely that the equipment will be accidentally misused. 
     SUMMARY 
     Apparatus and associated methods may relate to a Self-Retracting Lifeline Connecting System (SRLCS) that securely attaches to a fall-protection safety harness, and further provides connections to a plurality of safety devices. In an illustrative example, the SRLCS may include a D-pad adapted for rear attachment to a back-pad of a safety harness. In some examples the D-pad may have webbing apertures through which two sections of webbing may be threaded in a criss-crossed manner. In some embodiments, the D-pad may provide an attachment for a first harness ring. In some exemplary embodiments, the D-pad may also provide a tunnel structure for routing a second harness ring therethrough. In an illustrative example, the tunnel may be located immediately adjacent to the criss-cross location of the two sections of webbing, thereby permitting a carabiner to make use of the tunnel to capture the two sections of webbing. 
     Various embodiments may achieve one or more advantages. For example, in some embodiments, where the tunnel is rigidly fixed to the D-pad, the weight of any attached safety equipment may substantially reduce or eliminate pulling on the webbing that tends to make the webbing sag. For example, the weight of attached equipment may be substantially supported by the rigid tunnel structure. Various embodiments may permit both carabiner and D-ring attachments to the webbing, the D-ring being available for a rescue hook attachment in the event of a fall. In another exemplary embodiment the tunnel structure may ease the capture of the webbing by a carabiner, because the tunnel may present an introduction behind the webbing to the open end of a carabiner. Some embodiments may employ a webbing retainer clip to help center the carabiner on the D-pad. Various embodiments may use a large webbing aperture of the webbing retainer clip to permit the webbing to readily slide as needed during operation. In some embodiments, the webbing is retained with a rotatable webbing retainer clip that substantially opposes/avoids any tendency to open the gate during a fall. In such a fall event, the webbing retaining clip may release from the carabiner, but because its rotation may oppose that of the first action of the carabiner&#39;s gate, any tendency to open the gate may be substantially reduced or minimized. In some embodiments, the use of SRL bushings may prevent or substantially reduce abrasion of the carabiner by the SRL swivel connectors. 
     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 
         FIGS. 1 a -1 c    depict a sketch of a field implementation of an exemplary Self-Retracting Lifeline Connecting System (SRLCS) used for fall protection. 
         FIGS. 2 a -2 b    depict two perspective views of a safety harness with an exemplary SRLCS with dual Self-Retracting Lifelines (SRLs) connected. 
         FIGS. 3 a -3 b    depict two close-up perspective views of a safety harness with an exemplary SRLCS showing a webbing tunnel. 
         FIGS. 4 a -4 b    depict two plan views of two exemplary D-pads. 
         FIGS. 5 a -5 c    depict a perspective and two side views of the installation of an exemplary D-pad clip used to create a webbing tunnel. 
         FIGS. 6 a -6 d    depict perspective, plan, top, and side views of an exemplary D-pad clip used to create a webbing tunnel. 
         FIGS. 7 a -7 b    depict two close-up perspective views of an exemplary SRLCS showing an exemplary webbing retainer clip. 
         FIG. 8  depicts a perspective view of a safety harness with an exemplary SRLCS showing exemplary SRL two-piece bushings. 
         FIGS. 9 a -9 d    depict a perspective view and plan views of an exemplary two-piece SRL bushing and side cross-sectional views of each bushing piece. 
     
    
    
     Like reference symbols in the various drawings indicate like elements. 
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     To aid understanding, this document is organized as follows. First, an exemplary SRLCS is briefly introduced with reference to  FIGS. 1-3 . Second, with reference to  FIGS. 4-6 , the discussion turns to exemplary embodiments that illustrate both the back-pad connection to a webbing harness and a tunnel to provide a carabiner a via to capture a webbing. Then, with reference to  FIG. 7 , an exemplary webbing retainer clip will be discussed. Finally, with reference to  FIGS. 8-9 , discussion will turn to exemplary SRL bushings which may be used to prevent abrasion of the connecting carabiner. 
       FIGS. 1 a -1 c    depict a sketch of a field implementation of an exemplary Self-Retracting Lifeline Connecting System (SRLCS) used for fall protection. In these figures, a workman  100  is working high above a river  105 . The workman is depicted wearing an exemplary SRLCS  110 . The SRLCS has two exemplary Self-Retracting Lifelines (SRLs)  115 ,  120  attached to the SRLCS  110 . Each SRL has a connection device  125 ,  130  which is attached to a girder  135  at two attachment locations  140 ,  145 . The SRLs  115 ,  120  are attached to the SRLCS  110  via a carabiner  150 . In this example, the carabiner  150  captures a webbing  155  of a harness  160 . In various examples, the weight of the two SRLs  115 ,  120  may not cause the webbing  155  to sag because the carabiner  150  supporting the SRLs  115 ,  120  is attached to a D-pad  165  in the harness  160  via a D-pad clip  170 . The D-pad clip  170  provides a tunnel  175 , throughout which the carabiner  150  resides. The D-pad clip  170  is rigidly attached to the D-pad  165  which has webbing slots that guide the webbing  155  in a criss-cross fashion  180  over the D-pad clip. The tunnel  175  not only supports the weight of the carabiner  150  and the two SRLs  115 ,  120 , but also provides a pathway to receive and guide the carabiner  150  behind the webbing  155 , which ensures easy and proper installation. The carabiner&#39;s use of the tunnel pathway  175  provided by the D-pad clip  170  can be used in addition to a D-ring  185 , which may then be available if a rescue hook is needed. The D-ring  185  can then be free of the heavy SRLs  115 ,  120  so that it doesn&#39;t cause the webbing  155  to sag, and its aperture is free for emergency use. 
       FIGS. 2 a -2 b    depict two perspective views of a safety harness with an exemplary SRLCS with dual Self-Retracting Lifelines (SRL) connected. In  FIGS. 2 a -2 b   , an exemplary SRLCS  200  is depicted with two exemplary SRLs  205 ,  210  attached to a carabiner  215 . The carabiner is shown with an exemplary gate  220 . The non-gate portion  225  of the carabiner  215  has a small cross-sectional diameter  230 . The gate  220  has a large cross-sectional diameter  235 . The SRLs  205 ,  210  are attached on either side of the gate  220 . Each SRL  205   210  is attached to the carabiner via a swivel connector  240 ,  245 . The large cross-sectional diameter  235  of the gate provides separation of the two SRLs  205 ,  210 . In this example, the gate requires at least two separate and distinct actions to open. One, the gate  220  must be twisted. Two, the gate must be opened. Only after the twist has been performed may the gate  220  be swung open. A webbing retainer clip  250  is connected to the carabiner  215 . Also depicted in this exemplary figure is a D-ring  255 . The D-ring  255  has a large device aperture  260 , which may be used by a safety hook in an emergency situation or by other connecting devices. 
       FIGS. 3 a -3 b    depict two close-up perspective views of a safety harness with an exemplary SRLCS showing a webbing tunnel. In  FIGS. 3 a -3 b   , an exemplary D-pad  300  is depicted. Two sections of webbing  305   310  are also depicted. The webbing criss-crosses at a crossover point  315 . This exemplary D-pad is depicted with six distinct webbing apertures  320 ,  325 ,  330 ,  335 ,  340 ,  345 . In this exemplary figure, each piece of webbing  305 ,  310  is threaded through four of the six apertures  320 - 345 . The first webbing section  305  is serially threaded through webbing apertures  320 ,  330 ,  335 ,  345 . The second webbing aperture  310  is threaded through webbing apertures  325 ,  330 ,  335 ,  340 . As depicted in this example, a carabiner  350  has captured both sections of the webbing  305 ,  310  at a location near the crossover point  315 . In this illustrative embodiment, a D-ring  355  is depicted as having captured the two sections of webbing  305 ,  310  at a location near the crossover point  315  as well. In  FIG. 3 b   , an exemplary D-pad clip  360  is depicted. The carabiner  350  is shown residing within a tunnel  365  formed in the D-pad clip  360 . 
       FIGS. 4 a -4 b    depict two plan views of two exemplary D-pads. In  FIG. 4 a   , an exemplary D-pad  400  is depicted. In this example, the exemplary D-pad  400  is depicted with six webbing apertures  402 ,  408 ,  414 ,  420 ,  426 ,  432 . Aperture  402  has a major dimension  404  and a minor dimension  406 . Aperture  408  has a major dimension  410  and a minor dimension  412 . Aperture  426  has a major dimension  428  and a minor dimension  430 . Aperture  432  has a major dimension  434  and a minor dimension  436 . In this exemplary embodiment, major dimension  404  is approximately parallel to major dimension  434 . Also approximately parallel in this example are major dimensions  410  and  428 . A perpendicular bisector  438  of major dimension  404  also approximately bisects major dimension  434  in a nearly perpendicular fashion in this exemplary figure. A perpendicular bisector  440  of major dimension  410  also approximately bisects major dimension  428  in a nearly perpendicular fashion. The perpendicular bisector  438  has a midpoint  442  between the two major dimensions  404 ,  434  that it bisects. The perpendicular bisector  440  has a midpoint  444  between the two major dimensions  410 ,  428  that it bisects. The two midpoints  442 ,  444  are nearly coincident in this exemplary D-pad figure. A section of webbing can be threaded through apertures that share a perpendicular bisector, without requiring the webbing to twist or turn except in the direction of its thickness. If one were to thread a section of webbing through apertures  402  and  432 , for example, no twisting of turning of the webbing may be required except in the direction of its thickness. Note that this section of webbing that goes through apertures  402  and  432  can also go through the larger webbing apertures  414   420 , which both reside between apertures  402 ,  432 . A section of webbing that may be threaded through apertures  408 ,  426  may also go through apertures  414 ,  420 . In this manner, apertures  414 ,  420  are shared apertures. 
     In  FIG. 4 b   , another exemplary D-pad  450  is depicted. In this example, the exemplary D-pad is depicted with eight webbing apertures  460 ,  462 ,  464   466 ,  468 ,  470 ,  472 ,  474 . In this exemplary figure, apertures  460 ,  462 ,  472 ,  474  all have major dimensions parallel to each other and all approximately share a perpendicular bisector  480 . Apertures  464 ,  466 ,  468 ,  470  all have major dimensions parallel to each other and all approximately share a perpendicular bisector  484 . These two bisectors  480 ,  484  cross at an approximate midpoint  486  between the symmetric aperture pairs, ( 460  and  474  being symmetric,  462  and  472  being symmetric,  464  and  470  being symmetric, and  466  and  468  being symmetric). In this exemplary embodiment a section of webbing can be threaded through apertures  460 ,  462 ,  472 ,  474  without having to turn or twist except in the direction of its thickness. Another section of webbing can be threaded through apertures  464 ,  466 ,  468 ,  470  without having to turn or twist except in the direction of its thickness. The two sections of webbing may then criss-cross at or near the midpoint  486 . 
       FIGS. 5 a -5 c    depict a perspective view and two side views of the installation of an exemplary D-pad clip used to create a webbing tunnel. In  FIGS. 5 a -5 c   , an exemplary D-pad is depicted  500 . The D-pad  500  has a top surface  505  and a bottom surface  510 . The D-pad is shown attached to a D-ring  515 . A D-pad clip  520  is shown being inserted into the D-pad  500  in  FIG. 5 a   .  FIG. 5 b    shows a side cross-sectional view of the D-pad clip  520  being inserted into the D-pad  500 .  FIG. 5 c    shows a side cross-sectional view of the D-pad clip when it is attached to the D-pad  500 . In this exemplary embodiment, the D-pad clip has a tunnel  525  that is parallel to the top surface  505  of the D-pad  500 . This example depicts the tunnel at a location where the crossover point of two sections of threaded webbing may be in close proximity to the tunnel. In this exemplary embodiment the D-pad clip  520  clips onto the D-pad  500 . In some embodiments, a D-pad clip may be created as part of a unitary D-pad. In other exemplary embodiments, a D-pad clip may be attached to a D-pad using a screw or screws. Some embodiments may affix a D-pad clip to a D-pad with one or more rivets. Some exemplary embodiments may affix a D-pad clip to a D-pad using adhesives. 
       FIGS. 6 a -6 d    depict perspective, plan, top, and side views an exemplary D-pad clip used to create a webbing tunnel. In  FIG. 6 a   , a perspective view of an exemplary D-pad clip  600  is shown in isolation.  FIG. 6 b    depicts a plan view perspective of the same exemplary D-pad clip  600 . In  FIG. 6 c   , a top perspective view of the same exemplary D-pad clip  600  is shown. And in  FIG. 6 d   , a side perspective view of the same exemplary D-pad clip  600  is shown. A tunnel  605 , through which a carabiner may be inserted is depicted in  FIG. 6   d.    
       FIGS. 7 a -7 b    depict two close-up perspective views of an exemplary SRLCS showing an exemplary webbing retainer clip. In  FIGS. 7 a -7 b   , an exemplary webbing retainer clip  700  is depicted. In  FIG. 7 a   , the webbing retainer clip  700  is shown attached at three points  705 ,  710 ,  715  to a carabiner  720 . The first attachment point  705  is located at a gate  725  of the carabiner  720 . The second and third attachment points  710 ,  715  are located near a tunnel  730  of a D-pad clip  735 . The first attachment point  705  completely circumscribes the gate  725 , and thus must be attached when the gate  725  is open. The first attachment point  705  is loosely coupled to the gate  725  and can freely rotate about the gate  725 . This loose coupling may permit the webbing retainer clip  700  to rotate freely about the gate  725  in the event of a fall or other such shock event. Because the webbing retainer clip  700  can freely rotate about the gate  725 , it will not rotate the gate  725  in such an event, which might otherwise serve to perform the first action needed to open the gate  725 . The second and third attachment points  710 ,  715  snap onto the carabiner. The second and third attachment points  710 ,  715 , together with a section of the carabiner  730  define a webbing aperture  735 . The two sections of webbing that may be inserted into the D-pad may be inserted through this defined webbing aperture  735  near the criss-cross point of the two sections of webbing. The webbing retainer clip may help to keep the carabiner centered upon the webbing. Its large defined webbing aperture  735  may permit ease of installation. This large defined webbing aperture  735  also may permit the sections of webbing which thread therethrough to slide freely without binding. 
       FIG. 8  depicts a perspective view of a safety harness with an exemplary SRLCS showing exemplary SRL two-piece bushings. In  FIG. 8 , an exemplary SRLCS  800  is depicted. In this exemplary embodiment, two SRLs  805 ,  810  are connected to a carabiner  815 . Each SRL  805 ,  810  is connected to the carabiner  815  via a swivel connector  820   825 . Each swivel connector  820 ,  825  in this example has a bushing  830 ,  835 . The bushing may be made of a synthetic material to help prevent abrasion of the carabiner  815  as the swivel connectors  820 ,  825  move during use. 
       FIGS. 9 a -9 d    depict a perspective view and plan views of an exemplary two-piece SRL bushing and side cross-sectional views of each bushing piece. In  FIG. 9 a   , an exemplary two-piece bushing is depicted in an assembled state  900 .  FIG. 9 b    shows the same exemplary two-piece bushing  900  in a plan view.  FIGS. 9 c -9 d    show each individual piece  905   910  of this exemplary two-piece assembly. A bushing surface  915  is depicted in  FIGS. 9 a -9 d   . This bushing surface  915  is the surface that will contact the outer surface of a carabiner when SRLs are attached to it. 
     Although various embodiments have been described with reference to the figures, other embodiments are possible. For example, a flexible D-pad may be used along with a semi-rigid D-pad clip. In some embodiments, a D-pad may be semi-rigid and a rigid or semi-rigid D-pad clip may be affixed to it. In various embodiments, a tunnel created by a D-pad clip may be made longer or shorter. Some exemplary embodiments may integrate the D-pad clip into the D-pad itself. In accordance with another embodiment, a D-pad clip may have two parallel tunnels presenting the user with a choice of tunnels to use. In another embodiment, a D-pad clip may provide for connection of a D-ring in addition to providing a tunnel. 
     In various embodiments, apparatus and methods may involve webbing retainer clips made of plastic. In another exemplary embodiment the webbing retainer clip may be secured to the carabiner with one or more screws or bolts. In accordance with another embodiment, the webbing retainer clip may be made with second and third attachment points that connect to a D-pad clip instead of or in addition to connecting to a carabiner. In an exemplary embodiment, single piece SRL bushings may be used. These bushings may snap into the swivel connection from one side of the swivel connection aperture. In accordance with another embodiment, the bushings may be made of a material with an embedded lubricant, such as graphite. 
     In one exemplary aspect, a method of constructing a fall-protection safety harness includes providing a wearable safety harness including a length of webbing, providing a D-pad having a top and a bottom surface, the D-pad including webbing apertures for attachment to a webbing, providing a D-pad clip attachable to the D-pad, the D-pad clip providing a lumen located adjacent to the top side of the D-pad at or near the location of the location of the webbing criss-cross and oriented about approximately parallel to the top surface of the D-pad, and inserting at least a portion of the length of the webbing through the webbing aperture to securely couple the unitary solid body to the safety harness. 
     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.