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RELATED APPLICATIONS  
       [0001]     The present application is based upon U.S. Provisional Application Nos. 60/624,206 filed Nov. 2, 2004; 60/630,019 filed Nov. 22, 2004; 60/641,385 filed Jan. 4, 2005 and 60/669,503 filed Apr. 8, 2005; the entire subject matter of each of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to the field of construction, and, more particularly, to the field of temporary railings for buildings and associated methods.  
       BACKGROUND OF THE INVENTION  
       [0003]     A temporary railing may be used to protect construction workers at an elevated construction site. Such a temporary railing may generally employ a series of stanchions spaced around the boundary of a building floor and a set of parallel cables carried by the stanchions. The parallel cables are manually tensioned by turnbuckles and/or winches to thereby form a substantially rigid grid on the boundary or perimeter of the construction site. For example, such a typical railing is disclosed in U.S. Pat. No. 6,053,281 to Murray, wherein winches are used to set the initial tension of the cables. U.S. Pat. Nos. 3,881,699 and 6,270,057 also disclose conventional temporary railings for a building floor.  
         [0004]     Another type of building fall protection system includes a safety cable or safety line to which the lanyard of a worker&#39;s safety harness may be slidably connected while erecting a steel framework, for example, as disclosed in U.S. Pat. No. 6,036,146. U.S. Pat. No. 6,412,598 to Mackinnon discloses a similar safety line as does U.S. Pat. No. 6,270,057 to Highley et al. Such a safety line typically is required to provide a shock absorbing feature should a worker fall, such as disclosed in U.S. Pat. No. 5,332,071. In contrast, it is generally desired that a temporary railing for a building floor apply a relatively large tension to the cables, and that the cables are not readily moved by contact by a worker, for example.  
         [0005]     Unfortunately, the current temporary railings need periodic manual adjustments to maintain the cable tension to counteract the elongation of the cables, and/or the slight movement of various stanchions that would otherwise cause slack and thereby release the cable tension. Such a manual maintenance requirement can require many man hours, especially where temporary railings are used on multiple floors of a building.  
         [0006]     Another drawback of a conventional cable railing is that it typically requires that the entire railing be released and lowered to permit a user to move heavy equipment past the railing. Alternatively, the heavy equipment needs to be lifted over the railing.  
         [0007]     The boundary of a typical building floor may also include various corners. A simple eye for receiving the cable can be attached to a vertical building member at a corner, but is likely to increase resistance to tensioning. Of course, the corner may be inside or outside corners depending on the railing.  
       SUMMARY OF THE INVENTION  
       [0008]     In view of the foregoing background, it is therefore an object of the present invention to provide a temporary railing for a boundary of a building floor that permits ready temporary access therethrough.  
         [0009]     This and other objects, features and advantages in accordance with the present invention are provided by a temporary railing for a boundary of a building floor comprising a plurality of temporary cable supports spaced along the boundary of the building floor, a plurality of vertically spaced apart cables carried by the temporary cable supports to extend along the boundary of the building floor, an access opening assembly for permitting temporary establishment of an access opening through each of the cables. The access opening assembly may include a cable jack selectively coupled in line with a respective cable and movable between a released position and a closed position, and at least one cable clamp selectively clamped to the respective cable to maintain tension beyond the access opening when the cable jack is in the released position. The access opening assembly may further comprise an openable link selectively coupled in line with the respective cable adjacent the cable jack. The openable link may include a hook and an eye to receive the hook therein.  
         [0010]     The cable jack may include first and second end members, a pivot member between the first and second end members, and a handle member coupled to the pivot member. The access opening assembly may further comprise a cable jack lock to lock the handle member in the closed position.  
         [0011]     The at least one cable clamp may comprise a primary cable clamp, and a back-up cable clamp to be coupled to the respective cable adjacent the primary cable clamp. The at least one clamp may further comprise a tether coupling the primary cable clamp and the back-up cable clamp together. For example, the primary cable clamp may include a pair of adjustable cable gripping jaws, and a pair of handles extending outwardly from the cable gripping jaws. The primary cable clamp may further comprise a locking pin associated with the pair of handles.  
         [0012]     The plurality of temporary cable supports may comprise at least one stanchion temporarily secured to the building floor. The at least one stanchion may have an adjustable height. The building may comprise at least one vertical building member and the plurality of temporary cable supports may comprise at least one pulley temporarily secured to the at least one vertical building member.  
         [0013]     A method aspect is for permitting temporary establishment of an access opening through each of a plurality of vertically spaced apart cables carried by temporary cable supports spaced along a boundary of a building floor. The method may include selectively coupling a cable jack in line with a respective cable and movable between a released position and a closed position; and selectively clamping at least one cable clamp to the respective cable to maintain tension beyond the access opening when the cable jack is in the released position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a schematic diagram of a portion of a temporary railing according to the invention.  
         [0015]      FIG. 2  is a schematic diagram of the portable cable tensioning apparatus in  FIG. 1 .  
         [0016]      FIG. 3  is another schematic diagram of a portion the portable cable tensioning apparatus in  FIG. 1 .  
         [0017]      FIG. 4  is another schematic diagram of a portion the portable cable tensioning apparatus in  FIG. 1 .  
         [0018]      FIG. 5  is a schematic diagram of an alternative embodiment of the portable cable tensioning apparatus in  FIG. 1 .  
         [0019]      FIG. 6  is a schematic diagram of the alternative embodiment of the portable cable tensioning apparatus in  FIG. 5 .  
         [0020]      FIG. 7  is a schematic diagram of an alternative embodiment of a portable cable tensioning apparatus to be used in the temporary railing in accordance with the present invention.  
         [0021]      FIG. 8  is a schematic diagram of another alternative embodiment of a portable cable tensioning apparatus to be used in the temporary railing in accordance with the present invention.  
         [0022]      FIG. 9  is a side elevation view of a primary cable clamp for defining an access opening in the temporary railing in accordance with the invention.  
         [0023]      FIG. 10  is a side elevation view of a cable jack for defining an access opening in the temporary railing in accordance with the invention.  
         [0024]      FIG. 11  is a front elevation view of the connecting link of the cable jack of  FIG. 10 .  
         [0025]      FIG. 12  is a side elevation view of the extension arm of the cable jack of  FIG. 10 .  
         [0026]      FIG. 13  is a top plan view of the hinge pin of the cable jack of  FIG. 10 .  
         [0027]      FIG. 14  is a top plan view of the cable jack of  FIG. 10 .  
         [0028]      FIGS. 15-18  are side perspective views of the primary and second cable clamps of the temporary railing illustrating securing for defining an access opening in accordance with the invention.  
         [0029]      FIG. 19  is a side perspective view of the primar and secondary cable clamps shown in the clamped position in accordance with the invention.  
         [0030]      FIG. 20  is a top perspective view of a cable jack for defining an access opening in the temporary railing in accordance with the invention.  
         [0031]      FIG. 21  is a top perspective view of the cable jack in  FIG. 20  show in the released position.  
         [0032]      FIG. 22  is a schematic diagram of a section of the temporary railing in accordance with the invention illustrating the components for establishing the access opening.  
         [0033]      FIG. 23  is a schematic plan view of the temporary railing in accordance with the invention.  
         [0034]      FIG. 24  is an enlarged perspective view of an embodiment of a fastening arrangement for the bottom plate of the cable tensioning apparatus shown in  FIG. 3 .  
         [0035]      FIG. 25  is an end elevation view of an alternative embodiment of the cable tensioning apparatus in accordance with the invention and illustrated with the mesh doors removed for clarity.  
         [0036]      FIG. 26  is a side elevation view of the alternative embodiment of the cable tensioning apparatus shown in  FIG. 25 .  
         [0037]      FIG. 27  is an end elevation view of an alternative embodiment of the cable tensioning apparatus in accordance with the invention and illustrated with the mesh doors in place.  
         [0038]      FIG. 28  is a side elevation view of the alternative embodiment of the cable tensioning apparatus shown in  FIG. 27 .  
         [0039]      FIG. 29  is an end elevation view of an alternative embodiment of the cable tensioning apparatus in accordance with the invention and illustrated with the mesh doors in place and showing interior portions.  
         [0040]      FIG. 30  is a side elevation view of the alternative embodiment of the cable tensioning apparatus shown in  FIG. 29 .  
         [0041]      FIG. 31  is an end elevation view of yet another alternative embodiment of the cable tensioning apparatus as shown in  FIG. 8 .  
         [0042]      FIG. 32  is a side elevation view of the cable tensioning apparatus as shown in  FIG. 31 .  
         [0043]      FIG. 33  is a side elevation view of the cable tensioning apparatus as shown in  FIGS. 27 and 28  with a side door open.  
         [0044]      FIG. 34  is an interior perspective view of top pulleys in the cable tensioning apparatus as shown in  FIG. 33 .  
         [0045]      FIG. 35  is another interior perspective view of further pulleys in the cable tensioning apparatus as shown in  FIG. 33 .  
         [0046]      FIG. 36  is another interior perspective view of lower pulleys in the cable tensioning apparatus as shown in  FIG. 33 .  
         [0047]      FIG. 37  is a perspective view of cable yoke and associated pulleys in the cable tensioning apparatus shown in  FIG. 33 .  
         [0048]      FIG. 38  is a top plan view of an embodiment of a corner pulley for use in the temporary railing in accordance with the invention.  
         [0049]      FIG. 39  is a front elevation view of the pulley shown in  FIG. 38 .  
         [0050]      FIG. 40  is a side elevational view of the pulley shown in  FIG. 38 .  
         [0051]      FIG. 41  is a top perspective view of another embodiment of a corner pulley for use in the temporary railing in accordance with the invention.  
         [0052]      FIG. 42  is a side elevation view of the corner pulley as shown in  FIG. 41 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0053]     The invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime and multiple prime notations are used in alternative embodiments to indicate similar elements.  
         [0054]     The basic components and interconnections of a temporary railing  10  in accordance with the invention are now described with reference to  FIG. 1 . The temporary railing  10  illustratively includes a pair of cables  12   a ,  12   b  strung between a stanchion  16   a  and a yoke  14 . The stanchion  16   a  may be a column and/or other vertical building member as will be appreciated by those of skill in the art.  
         [0055]     One end of each of the cables  12   a ,  12   b  terminates at the yoke  14  and the yoke is connected to a yoke pulley  22 . The yoke  14  accommodates different lengths for the cables  12   a ,  12   b  by pivoting around the axis of the yoke pulley  22 .  
         [0056]     The cables  12   a ,  12   b  pass through guide eyehooks  18   a ,  18   b  that are fastened to the stanchion  16   a . The guide eyehooks  18   a ,  18   b  serve to help maintain the position of the cables  12   a ,  12   b  in relation to the stanchion  16   a . Other positioning devices similar to guide eyehooks  18   a ,  18   b  are also envisioned as will be appreciated by those skilled in the art. Horizontally extendable sliding rails  17   a ,  17   b  extend outwardly from the cable tensioning apparatus or tower  20  as used hereafter and may assist in preventing the cables  12   a ,  12   b  from twisting by maintaining the yoke  14  in the proper plane.  
         [0057]     Referring additionally to  FIG. 2 , one end of each adjustable sliding rail  17   a ,  17   b  is fitted to slide through respective brackets  38   a ,  38   b . A thumbscrew may be arranged in the surface of each of the brackets  38   a ,  38   b  to enable the adjustable sliding rails  17   a ,  17   b  to be fixed in position when each thumbscrew is turned until it bottoms out against each respective adjustable sliding rail  17   a ,  17   b . The adjustable sliding rails  17   a ,  17   b  are also illustratively shown to include twist eyehooks  42   a ,  42   b  that may help to keep the fall protection cables  12   a ,  12   b  from twisting.  
         [0058]     The tower  20  may support a medial pulley  26  and an upper pulley  28  that are spaced apart on the tower. The tower  20  may also carry a tower set point winch  24  that is used to tension a tower cable  30 .  
         [0059]     The cable  30  is strung through the tower set point winch  24 , yoke pulley  22 , medial pulley  26 , and upper pulley  28 . The end of the tower cable  30  from the upper pulley  28  is connected to the removable weights  32 . The weights may move in a path that may be guided by the tower  20 .  
         [0060]     The weight stack  32  provides a tensioning force on tower cable  30 . The force is transmitted along the tower cable  30  where it exerts a force on the yoke  14  thereby keeping the cables  12   a ,  12   b  under a selected tension even during elongation of the cables or based upon slight movement of the cable supports as will be appreciated by those skilled in the art. Adding or subtracting any number of weight plates  36  to the tower weight stack  32  may be used to adjust the tension force generated.  
         [0061]     Turning now additionally to  FIGS. 25-28 , alternative embodiments of the tower  20 ′,  20 ″ are now described. The towers  20 ′,  20 ″ are fabricated from square tubing although other materials such as round tubing and angle iron may also be used. Transport brackets  19 ′,  19 ″ are illustratively shown mounted on top of the towers  20 ′,  20 ″. The transport brackets  19 ′,  19 ″ each have a hole through which a cable, clevis hook, shackle clevis or the like may be attached to readily facilitate the transport of the towers  20 ′,  20 ″ as will be appreciated by those of skill in the art. Each of the internal cables  30 ′,  30 ″ is strung through a plurality of pulleys  27   a ′- 27   e ′ and  27   a ″- 27   e ″ connected to the towers  20 ′,  20 ″.  
         [0062]     Each of the internal cables  30 ′,  30 ″ is connected to the respective weight stack  32 ′,  32 ″. The tension of each of the internal cables  30 ′,  30 ″ is controllable by adjusting the weight stack  32 ′,  32 ″. Rotating the winch handle  33 ″ of tower set point winch  24 ′,  24 ″ permits setting the length of the internal cable  30 ′,  30 ″ so that the weight stack  32 ′,  32 ″ does not move to the bottomed out position during normal operation as will be appreciated by those skilled in the art.  
         [0063]     Each of the towers  20 ′,  20 ″ illustratively includes side panels  30 ′,  31 ″ made of sheet metal and wire mesh to thereby enclose the internal components of the tower as will be appreciated by those of skill in the art. The towers  20 ′,  20 ″ illustratively include storage holds  29 ′,  29 ″ at the bottom area.  
         [0064]     Referring additionally to  FIGS. 29 and 30 , in an alternative embodiment, the force transmitted on the tower cable  30  may be applied by a tension spring  37 ′″ or the like as will be appreciated by those skilled in the art. The tension spring  37 ′″ is carried by housing  35 ′″.  
         [0065]     The tower  20  is shown as having a bottom plate  40  at one end of the tower (See  FIGS. 2 and 3 ). The bottom plate  40  may be used to fasten the tower  20  in a selected position by bolting the bottom plate directly to the floor of the installation site, for example.  
         [0066]     Alternately, as illustrated in  FIG. 24 , the bottom plate  40  may be elevated off the floor of the installation site by using a combination of all-threaded rods  25   a - 25   d  and a plurality of all-threaded rod fasteners  27   a - 27   d  such as nuts as will be appreciated by those of skill in the art. Additionally, each all-threaded rod  25   a - 25   d  may be connected to a respective optional foot  29   a - 29   d . The elevated position of the bottom plate  40  permits the tower  20  to be installed on an unfinished surface, which will receive concrete poured at later date, for example. The elevated configuration permits the concrete to be poured without the tower  20  being moved. For instance, after the concrete is poured, the tower  20  can be removed and the all-threaded rods  25   a - 25   d  may be cutoff flush with the floor as will be appreciated by those of skill in the art.  
         [0067]     In another embodiment of the invention, each of the all-threaded rods  25   a - 25   d  may be sleeved in a properly sized piece of pipe (not shown) such as PVC pipe to protect the all-threaded rods  25   a - 25   d  from the concrete poured to produce the finished floor surface. After the concrete pour, the all-threaded rods  25   a - 25   d  may be unscrewed from the new concrete floor, the PVC pipe may be cut flush with the new floor surface, and the remaining holes patched.  
         [0068]     Referring now additionally to  FIGS. 3, 4 ,  5 , and  6 A, the medial pulley  26  is fastened to the tower  20  by a bracket  42 , and the tower  20  may be carried by a tower housing  52 . The fall protection cables  12   a ,  12   b  may be pulled to the tower  20  by a winching device as is shown in  FIG. 4 . A pair of chain loops  42   a ,  42   b  are shown in  FIG. 5  and may be fastened to the tower  20 . The chain loops  42   a ,  42   b  enable the tower  20  to be secured to a stanchion  16   b  or vertical building member  16   a  by respective chains  44   a ,  44   b.    
         [0069]     The tower  20  may also include a set of wheels  48  that facilitate the movement of tower  20  to different locations, and a handle  46  that aids in the positioning of tower  20 . The tower  20  may also include an adjustable level  50  that is used to position the height of the set of wheels  48  in relation to tower  20 . For example, the adjustable level  50  may be used to raise the set of wheels  48  in relation to the tower  20  thereby allowing the base of tower to contact the ground. As such, the tower  20  may be easier to secure in a selected position.  
         [0070]     Turning now additionally to  FIG. 7  another embodiment of a tower  100  is now described. The tower  100  includes a housing or frame  101  that illustratively carries two pulleys  102 ,  103  for directing a tensioning cable  104  from the yoke as described above (not shown here for clarity) to the piston rod  105  of the hydraulic cylinder  107 . The piston rod  105 , in turn, is connected to a piston  108  within the cylinder as will be appreciated by those skilled in the art.  
         [0071]     A hydraulic fluid  110  is supplied from the hydraulic reservoir  111  to the high pressure side of the cylinder  107  by the hydraulic pump  112  under control of the controller  115 . The controller  115  is connected to a pressure sensor  116  that is, in turn, connected to the cylinder  107 . A control panel, not shown, may be used by an operator to set a desired tension that will be used by the controller  115  to control the hydraulic pressure to thereby maintain the selected tension on the guard cables. The controller  115  and pump  112  are illustratively electrically powered via a storage battery  117  that may be recharged during daylight hours by the solar panels  118  as will be appreciated by those skilled in the art. Other powering schemes are also contemplated by the present invention.  
         [0072]     Another tower  120  embodiment is now described with reference to  FIG. 8 . In this tower  120 , a pneumatic or air pump  132  is used to maintain the desired air pressure in the cylinder  127  to thereby maintain the desired tension in the guard cables. The tower  120  includes a housing or frame  121  that illustratively carries two pulleys  122 ,  123  for directing a tensioning cable  124  from the yoke as described above (not shown here for clarity) to the piston rod  125  of the hydraulic cylinder  127 . The piston rod  125 , in turn, is connected to a piston  128  within the cylinder as will be appreciated by those skilled in the art. Air is supplied to the high pressure side of the cylinder  127  by the air pump  132  under control of the controller  135 . The controller  135  is connected to a pressure sensor  136  that, in turn, is connected to the cylinder  127 .  
         [0073]     A control panel, not shown, may be used by an operator to set a desired tension that will be used by the controller  135  to control the air pressure to thereby maintain the selected tension on the guard cables. The controller  135  and pump  132  are illustratively electrically powered via a storage battery  137  that may be recharged during daylight hours by the solar panels  138  as will be appreciated by those skilled in the art. Other powering schemes are also contemplated by the present invention. Referring now additionally to  FIGS. 31 and 32 , in an alternate embodiment of tower  120 ′, an air supply tank  139 ′ is connected to the hydraulic cylinder  127 ′ and air pump  132 ′ as will be appreciated by those of skill in the art.  
         [0074]     Referring now to  FIG. 9 , a cable clamp  60  used in conjunction with the temporary railing  10  is now described. The cable clamp  60  includes cable gripping jaws  62   a ,  62   b  that are operable to securely hold one of the fall protection cables  12   a ,  12   b , for example, when handles  64   a ,  64   b  are in a closed position. Moving the handle  64   a  away from the handle  64   b , the open position, releases the cable gripping jaws  62   a ,  62   b  from a respective fall protection cable  12   a ,  12   b.    
         [0075]     The gap between the cable gripping jaws  62   a ,  62   b  may be adjusted by an adjustment screw  66  located at one end of the handle  64   a  as will be appreciated by those of skill in the art. The cable clamp  60  may be fabricated by modifying a set of curved jaw locking pliers to include handles  64   a ,  64   b  although other embodiments will be apparent to one skilled in the art. The cable clamp  60  further includes a tether  68  connected to a threaded U-bolt  70 .  
         [0076]     Referring now to  FIGS. 10-14 , a cable jack  72  used in conjunction with the temporary railing  10  and the cable clamp  60  is now described. The cable jack  72  includes a handle  74  rotatably connected at a medial position by a pivot member  76  to a first member  78 , which is connected to a carabiner  80 . One end of the handle  74  is connected by a pin  82  to a second member  84 , which is connected to a handle carabiner  86 .  
         [0077]     The cable clamp  60  is positioned onto one of the fall protection cables  12   a ,  12   b  as is illustrated in  FIGS. 15-19 . The threaded U-bolt  70  is placed onto the fall protection cable  12   a  near the guide eyehook  18   a  of the stanchion  16   a . The threaded U-bolt  70  may then be secured to the fall protection cable  12   a  by a backing plate  71  fastened to the threaded U-bolt  70  by nuts  73   a ,  73   b  as will be appreciated by those of skill in the art. The secured U-bolt  70  may act as a back-up clamp  69  to the primary cable clamp  60 .  
         [0078]     The cable gripping jaws  62   a ,  62   b  may be positioned on the fall protection cable  12   a  between the back-up clamp  69  and the adjacent guide eyehook  18   a . The handles  64   a ,  64   b  are then moved to the closed position ( FIG. 17 ) thereby closing the cable gripping jaws  62   a ,  62   b  securely around the fall protection cable  12   a . The handles  64   a ,  64   b  may then be locked in the closed position by a locking pin  63  ( FIG. 17 ). Thus, the cable gripping jaws  62   a ,  62   b  create a stop to keep the fall protection cable  12   a  from traveling through the guide eyehook  18   a  when the fall protection cable  12   a  on the side of the guide eyehook  18   a  without the attached cable clamp  60  remains under tension.  
         [0079]     As will be appreciated by those of skill in the art, the temporary railing  10  may employ a plurality of stanchions  16   a - 16   j  that include any combination of permanent and temporary stanchions. A second cable clamp  60  and back-up clamp  69  may be attached to the fall protection cable  12   a  in a manner similar to the first cable clamp  60  and the back-up clamp  69 , but adjacent a stanchion  16   c  instead of the stanchion  16   a.    
         [0080]     A cable jack  72  may be connected to the fall protection cable  12   a  between the first and second back-up clamps  69 . In other words, referring now to  FIG. 22 , the layout along the fall protection cable  12   a  is the stanchion  16   a , the first primary cable clamp  60 , the first back-up clamp  69 , the cable jack  72 , the second back-up clamp  69 , the second primary cable clamp  60 , and then the stanchion  16   c.    
         [0081]     Referring now additionally to  FIGS. 20 and 21 , the cable jack  72  is connected to one end of the fall protection cable  12   a  by the connecting link carabiner  80 , and on the other end by the handle carabiner  86 . Of course, other methods of attachment are possible as will be appreciated by those of skill in the art.  
         [0082]      FIG. 20  illustrates the cable jack  72  in a closed position whereby the cable jack  72  transmits the tension from one end of the fall protection cable  12   a  to the other end of the fall protection cable  12   a . The cable jack  72  may be locked into the closed position by a cable jack lock  75 , which secures the handle  74  in a position adjacent to the fall protection cable  12   a.    
         [0083]     With the first and second cable clamps  60  secured into place on the fall protection cable  12   a  as described above, the cable jack  72  may be opened as illustrated in  FIG. 21 . As a result, it is possible for a user to unconnect the two ends of the fall protection cable  12   a  from the cable jack  72  and move them out of the way thereby permitting the user to move a load or equipment through an area between the stanchions  16   a  and  16   c  illustrated in  FIG. 22 . In addition, the rest of the fall protection cable  12   a  remains under tension because the first and second cable clamps  60  securely hold the remaining sections of the fall protection cable  12   a  under tension. In contrast, a conventional temporary railing system does not typically permit a section of the cable to be released from tension to permit user access through the area guarded by the temporary railing while the other sections of the same temporary railing remain under tension.  
         [0084]     Referring now additionally to  FIG. 23 , the temporary railing  10  may further include dual-use corner pulleys  88   a - 88   c . The dual-use corner pulleys  88   a - 88   c  may be attached to any one of the stanchions  16   a - 16   i , for example. The fall protection cable  12   a  may be routed around the dual-use corner pulleys  88   a - 88   c  and through a plurality of guide eyehooks  18   a  to facilitate the transmission of tension generated at the tower  20  by the tower weights  32 , not shown, for example. The dual-use corner pulleys  88   a - 88   c  are illustrated as connected on the inside corners of the temporary railing  10 , however, the dual-use corner pulleys  88   a - 88   c  may also be connected to the stanchions on the outside corners.  
         [0085]     An exemplary dual-use corner pulley  88   a  is now described with reference to  FIGS. 38-40 . The dual-use corner pulley  88   a  includes a yoke  150  comprising two flat s-shaped pulley arms  152   a ,  152   b . The pulley arms  152   a ,  152   b  are made of steel flatbar or other suitable material as will be appreciated by those of skill in the art. One end portion of each pulley arm  152   a ,  152   b  carries a pulley axle  154  on which a wheel  156  is rotatably mounted. The other end portion of each pulley arm  152   a ,  152   b  is connected to a mounting bracket  158 .  
         [0086]     In one embodiment, the mounting bracket  158  comprises steel angle, which facilitates the connection of the mounting bracket  158  to a corner of a stanchion  16   a  or beam as will be appreciated by those of skill in the art. This mounting bracket  158  further comprises a fastener slot  160  for connecting the mounting bracket to a stanchion  16   a  or beam with a welded hex nut as will be appreciated by those of skill in the art. The end portions of each pulley arm  152   a ,  152   b  connected to the mounting bracket  158  are v-shaped to receive the steel angle mounting bracket therein. The point of connection between each pulley arm  152   a ,  152   b  and the mounting bracket  158  are securely joined by welding or other suitable fastening technique as will be appreciated by those of skill in the art.  
         [0087]     An alternative embodiment of the dual-use corner pulley  88   a ′ is now described with reference to  FIGS. 41-42 . The wheel  156 ′ is removably carried by the yoke  150 ′ and secured in place by a removable axle pin  162 ′, which in turn is secured by cotter pin  164   a ′ and  164   b ′. Removal of the wheel  156 ′ facilitates the positioning of the fall protection cable  12   a  when the dual-use corner pulley  88   a ′ is used for an inside corner, for example. For instance, when the fall protection cable  12   a  is positioned within the yoke  150 ′, the wheel  156 ′ is then secured into position by the removable axle pin  162 ′ thereby permitting the inner surface of the wheel to cooperate with the yoke to capture the fall protection cable even if the cable is in a slack condition.  
         [0088]     When the dual-use corner pulley  88   a ′ is used on an outside corner, an outer surface of the wheel opposite the inner surface cooperates with a removable capture member  166  to capture the fall protection cable even if it is in a slack condition. The capture member  166  is positioned in openings  168   a ′ and  168   b ′ in the yoke  150 ′ as will be appreciated by those of skill in the art.  
         [0089]     The mounting bracket  158 ′ illustratively includes a pair of spaced apart mounting plates  170   a ′ and  170   b ′. Each mounting plates  170   a ′ and  170   b ′ may include fasteners  172   a ′ and  172   b ′, which are used to secure the mounting bracket to a building member, stanchion  16   a , or the like as will be appreciated by those of skill in the art.  
         [0090]     The dual-use corner pulley  88   a ′ may further include a weld plate  174 ′ connected to one of the mounting plates  170   a ′ and  170   b ′. The weld plate  174 ′ is to be secured to a building member, stanchion  16   a , or the like by welding thereby provided a secure connection while not damaging the mounting bracket  158 ′ as will be appreciated by those of skill in the art.  
         [0091]     Further, the dual-use corner pulley  88   a ′ may include a mounting bracket safety tether  180 ′ for securing the dual-use corner pulley to a respective vertical member. The mounting bracket safety tether  180 ′ is connected to the mounting bracket  158 ′ by a removable safety tether pin  176 ′. The safety tether pin  176 ′ is positioned in an opening  178 ′ in the yoke  150 ′ as will be appreciated by those of skill in the art. The mounting bracket safety tether  180 ′ is positioned around a building member, stanchion  16   a , or the like that the mounting bracket  158 ′ is secured to thereby providing a backup if such a connection should fail as will be appreciated by those of skill in the art. The mounting bracket safety tether  180 ′ comprises chain, cable, cord, or the like.  
         [0092]     An advantage of the temporary railing  10  may be that a constant and even tension may be maintained for all the sections of the cable run on the fall protection cable  12   a . For instance, test data from the experimental temporary railing  10  shown in  FIGS. 15-21  have generated a fairly equal tension of 2300-2600 pounds of tension throughout the entire run of cable. In comparison, a test performed on a typical conventional temporary railing system using a turnbuckle tightened by hand and one lever only generated about 700 pounds of tension on the fall protection cable. In addition, a test performed on a typical conventional guardrail fall protection system using a turnbuckle tightened by hand and three levers only generated about 1200 pounds of tension on the fall protection cable.  
         [0093]     Referring now additionally to  FIGS. 33-37 , the manner in which the tower cable  30 ″ is strung through the pulleys  27   a ″- 27   e ″ to yoke pulley  22 ″ in one embodiment is now described. The tower cable  30 ″ is attached to tower weights  32 ″ at one end as will be appreciated by those of skill in the art. The other end of the tower cable  30 ″ is strung through the pulleys  27   a ″ and  27   b ″ as is best seen in  FIG. 34 . The tower cable  30 ″ continues around pulley  27   b ″ and around pulley  27   c ″ ( FIG. 35 ) and then the tower cable leaves the tower  20 ″ to go out to yoke pulley  22 ″ as tower cable segment  39   a ″ ( FIG. 37 ). The tower cable segment  39   b ″ is then routed back into the tower  20 ″ and around pulley  27   d ″ or  27   e ″ ( FIG. 36 ).  
         [0094]     The selection of which pulley  27   d ″ or  27   e ″ depends on the height requirement of the tower cable  30 ″ as will be appreciated by those of skill in the art. For example, if the tower  20 ″ uses all-threaded rods  25   a - 25   d  to elevate the tower ( FIG. 33 ), then pulley  27   e ″ may be employed. In addition, pulleys  27   d ″ or  27   e ″ may be replaced by a single pulley on an adjustable track as will be appreciated by those of skill in the art.  
         [0095]     The tower cable segment  39   c ″ is then routed out to and around yoke pulley  22 ″, and tower cable segment  39   d ″ goes back to and around pulley  27   e ″. The tower cable segment  39   e ″ is then routed out to and around yoke pulley  22 ″, and the tower cable segment  39   f ″ returns to attach to the tower set point winch  24 ″. The amount of mechanical advantage gained by routing the tower cable segments  39   a ″- 39   f ″ between pulley  27   e ″ and yoke pulley  22 ″ may be changed by adding or reducing the number of cable segments passing between the pulley and yoke pulley as will be appreciated by those of skill in the art. The described pulley setup generated a multiplier of 6 to 7 times the weight or force applied.  
         [0096]     The tower set point winch  24 ″ is used to facilitate the tensioning of the tower cable  30 ″. The mechanical advantage gained by the pulley system of the tower  20 ″ permits a user to tension the tower cable  30 ″ with reduced effort as will be appreciated by those of skill in the art.  
         [0097]     In addition, other features relating to the temporary railing system are disclosed in co-pending patent applications assigned to the assignee of the present application entitled TEMPORARY RAILING FOR A BUILDING INCLUDING TENSIONING APPARATUS AND ASSOCIATED METHODS, attorney work docket number 59218, and entitled TEMPORARY RAILING FOR A BUILDING INCLUDING DUAL-USE CORNER PULLEY AND ASSOCIATED METHODS, attorney work docket number 59220, the entire disclosures of which are incorporated by reference. Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that other modifications and other embodiments are intended to be included.

Summary:
A temporary railing for a boundary of a building floor may include a plurality of temporary cable supports spaced along the boundary of the building floor, a plurality of vertically spaced apart cables carried by the temporary cable supports, and an access opening assembly for permitting temporary establishment of an access opening through each of the cables. The access opening assembly may include a cable jack selectively coupled in line with a respective cable and movable between a released position and a closed position, and at least one cable clamp selectively clamped to the respective cable to maintain tension beyond the access opening when the cable jack is in the released position.