Patent Abstract:
A safety anchor is removably attachable to a roof of a building. The safety anchor includes a portion receivable in a drain line of the roof. The safety anchor also includes a stem received in openings of the portion and an elastic member attached to the stem. The elastic member has an adjustable diameter, and the diameter of the elastic member is increased to contact walls of the drain line to secure the safety anchor to the roof.

Full Description:
REFERENCE TO RELATED APPLICATION 
     This application claim priority to U.S. Provisional Patent Application Ser. No. 61/239,490 filed Sep. 3, 2009. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to a safety anchor that is removably attachable to a building to restrain a worker when working on a roof of the building. 
     When repairing or constructing a roof, workers can be working at heights that are far from the ground. There is a need for a system that retains workers when working on roofs of buildings. 
     SUMMARY OF THE INVENTION 
     A safety anchor is removably attachable to a roof of a building. The safety anchor includes a portion receivable in a drain line of the roof. The safety anchor also includes a stem received in openings of the portion and an elastic member attached to the stem. The elastic member has an adjustable diameter, and the diameter of the elastic member is increased to contact walls of the drain line to secure the safety anchor to the roof. 
     In another exemplary embodiment, a safety system includes a safety anchor removably attachable to a roof of a building including a first portion connected to a second portion and a third portion connected to a second portion. The first portion, the second portion and the third portion are moveable relative to each other. At least one of the first portion, the second portion, and the third portion is receivable in a drain line of the roof. The first portion has a first diameter, the second portion has a second diameter, and the third portion has a third diameter. The first diameter is greater than the second diameter, and the second diameter is greater than the third diameter. The safety anchor also includes a threaded stem received in openings of the first portion, the second portion and the third portion, and an elastic member is attached to the threaded stem. The elastic member has an adjustable diameter, and the diameter of the elastic member is increased to contact walls of the drain line to secure the safety anchor to the roof. 
     These and other features of the present invention will be best understood from the following specification and drawings. 
    
    
     
       DETAILED DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a perspective view of a roof of a building; 
         FIG. 2  illustrates a cross-sectional view of the building; 
         FIG. 3  illustrates a cross-sectional view of a drain insert as a first example drain anchor in a fully extended position; 
         FIG. 4A  illustrates a cross-sectional view of a large portion of the drain insert; 
         FIG. 4B  illustrates a cross-sectional view of a medium portion of the drain insert; 
         FIG. 4C  illustrates a cross-sectional view of a small portion of the drain insert; 
         FIG. 5  illustrates a cross-sectional view of a pipe; 
         FIG. 6  illustrates a cross-sectional view of an all-thread center post; 
         FIG. 7  illustrates a cross-sectional view of the drain insert when used with a 6″ drain line; 
         FIG. 8  illustrates a cross-sectional view of the drain insert when used with a 4″ drain line; 
         FIG. 9  illustrates a cross-sectional view of the drain insert when used with a 3″ drain line; 
         FIG. 10  illustrates a wall bracket as a second example safety anchor; 
         FIG. 11  illustrates a first portion of the wall bracket; 
         FIG. 12  illustrates a second portion of the wall bracket; 
         FIG. 13  illustrates a safety clasp; 
         FIG. 14  illustrates a wall bracket as a third example safety anchor; 
         FIG. 15  illustrates a first portion of the wall bracket; 
         FIG. 16  illustrates a second portion of the wall bracket; 
         FIG. 17  illustrates a threaded eye bolt; 
         FIG. 18  illustrates a hitch pin; and 
         FIG. 19  illustrates a perspective view of the wall bracket. 
     
    
    
     The various features and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows: 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  illustrates a roof  20  of a building  22 . The roof  20  includes a drain basket  24  that cover a drain bowl  26  (shown in  FIG. 2 ) and a parapet wall  28  that surrounds a perimeter of the building  22 . In one example, the drain bowl  26  has a diameter of 12″ to 18″. As described below, a safety anchor (such as a drain insert  30  or a wall bracket  32  or  334 ) is secured to the building  22 . In one example shown in  FIGS. 2 to 9 , the drain insert  30  is received in a drain bowl  26 . In another example shown in  FIGS. 10 to 18 , the wall bracket  32  or  334  is secured to the parapet wall  28 . One end of a shock absorbing lanyard  34  is connected to the drain insert  30  or an eye bolt  236  or  336  (described below) of the wall bracket  32  and  334  by a carry ring (or D-ring)  100 , and another end of the lanyard  34  is attached to a harness  36  (shown schematically) that is worn by a worker  38 . Although both the drain insert  30  and the wall brackets  32  and  334  are shown in  FIG. 1 , only one of the drain insert  30  of the wall bracket  32  and  334  is used at a time. 
       FIG. 2  illustrates a cross-sectional view of the building  22 . The drain basket  24  covers the drain bowl  26 , which is in fluid communication with a drain line  41  that drains fluid or water from the roof  20  of the building  22 . The drain bowl  26  includes a bottom surface  111 . In one example, the drain line  41  is made of PVC or cast iron. In one example, the drain line  41  has a diameter of 3″, 4″ or 6″. The drain basket  24  is removable to expose the drain bowl  26 . 
       FIG. 3  illustrates a first example safety anchor, which in this embodiment is a drain insert  30 . In one example, the drain insert  30  can sustain 200 pounds of weight to meet OSHA fall prevention guidelines. The drain insert  30  has a compact position, a partially extended position, and a fully extended position. The drain insert  30  is shown in a fully extended position. In one example, the drain insert  30  is made of aluminum. 
     The drain insert  30  includes three hollow portions  40 ,  42  and  44 . A large portion  40  is designed to fit in a drain line  41  having a 6″ diameter, a medium portion  42  is designed to fit in a drain line  41  having a 4″ diameter, and a small portion  44  is designed to fit in a drain line  41  having a 3″ diameter. The portions  40 ,  42  and  44  telescope relative to each other. In the  FIG. 3  example, the drain insert  30  is used with a 6″ or 4″ drain line  41 . As  FIG. 3  shows a cross-sectional view, the dotted lines represent the portion of the components that are not located at the exact plane of the cross-section. 
     As shown in  FIG. 4A , the large portion  40  includes a cylindrical body  108 , an outwardly extending projection  46  that extends outwardly from a circumference of a top surface of the cylindrical body  108 , an inwardly extending projection  102  that extends inwardly from the top surface of the cylindrical body  108 , and an inwardly extending projection  50  that extends inwardly from a bottom surface of the cylindrical body  108 . The inwardly extending projection  102  defines an opening  64 , and the inwardly extending projection  50  defines an opening  48 . 
     As shown in  FIG. 4B , the medium portion  42  includes a cylindrical body  110 , an outwardly extending projection  52  that extends outwardly from a circumference of a top surface of the cylindrical body  110 , an inwardly extending projection  104  that extends inwardly from the top surface of the cylindrical body  110 , and an inwardly extending projection  56  that extends inwardly from a bottom surface of the cylindrical body  110 . The inwardly extending projection  104  defines an opening  66 , and the inwardly extending projection  56  defines an opening  54 . 
     As shown in  FIG. 4C , the small portion  44  includes a cylindrical body  112 , an outwardly extending projection  58  that extends outwardly from a circumference of a top surface of the cylindrical body  112 , an inwardly extending projection  106  that extends inwardly from the top surface of the cylindrical body  112 , and an inwardly extending projection  62  that extends inwardly from a bottom surface of the cylindrical body  112 . The inwardly extending projection  106  defines an opening  68 , and the inwardly extending projection  62  defines an opening  60 . 
     As shown in  FIG. 3 , the portions  40 ,  42  and  44  are arranged such that the outwardly extending projection  58  of the small portion  44  is received within a hollow interior of the medium portion  42 , and the outwardly extending projection  52  of the medium portion  42  is received within a hollow interior of the large portion  40 . 
     A diameter of the opening  54  of the medium portion  42  is large enough to allow the cylindrical body  112  of the small portion  44  to be received within and slide within the opening  54 . However, the engagement of the outwardly extending projection  58  of the small portion  44  and the inwardly extending projection  56  of the medium portion  42  prevents the portions  42  and  44  from separating. 
     A diameter of the opening  48  of the large portion  40  is large enough to allow the cylindrical body  110  of the medium portion  42  to be received within and slide within the opening  48 . However, the engagement of the outwardly extending projection  52  of the medium portion  42  and the inwardly extending projection  50  of the large portion  40  prevents the portions  40  and  42  from separating. 
     As shown in  FIG. 5 , the drain insert  30  also includes a pipe  70  that is received through the aligned openings  48 ,  54 ,  60   64 ,  66  and  68 . In one example, the pipe  70  has a substantially circular cross-section. The pipe  70  includes a cylindrical body  72  and an outwardly extending projection  74  that extends around an upper circumference of an upper end of the cylindrical body  72  to define an opening  109 . The cylindrical body  72  defines an opening  113  at a lower end. In one example, the pipe  70  is made of aluminum. The pipe  70  is received in the aligned openings  48 ,  54 ,  60   64 ,  66  and  68 . 
     As shown in  FIG. 6 , the drain insert  30  also includes an all-thread center post  76 . In one example, the all-thread center post  76  is 100% threaded. In one example, the all-thread center post  76  is made of stainless steel. The all-thread center post  76  includes a threaded stem  78  and a carry bar  80  attached to an upper end of the threaded stem  78 . The carry bar  80  includes two threaded projections  82  and  84 . The threaded stem  78  is received in the aligned openings  48 ,  54 ,  60   64 ,  66 ,  68 ,  109  and  110 . 
     Returning to  FIG. 3 , a washer  85  is located above the outwardly extending projection  74 . A wing-nut handle  87  is located on the threaded stem  78  between the washer  85  and the carry bar  80 . 
     Returning to  FIG. 3 , a plumber&#39;s plug  86 , or rubber gasket, is internally threaded and removably connected to a bottom end of the threaded stem  78 . The drain insert  30  includes three plumber&#39;s plugs  86 ,  88  and  90  each including an annular projection  92  around a center portion of each of the plumber&#39;s plug  86 ,  88  and  90 . A first plumber&#39;s plug  86  is used with the 6″ drain line  41 , a second plumber&#39;s plug  88  is used with the 4″ drain line  41 , and a third plumber&#39;s plug  90  is used with the 3″ drain line  41 . In the illustrated example of  FIG. 3 , the plumber&#39;s plug  86  is attached to the bottom end of the threaded stem  78 . The other two plumber&#39;s plug  88  and  90  are each threaded on one of the two threaded projections  82  and  84 , respectively, of the carry bar  80 . The plumber&#39;s plugs  86 ,  88  and  90  can be moved between the bottom end of the threaded stem  78  and the projections  82  and  84  of the carry bar  80  based on the diameter of the drain line  41 . 
     The plumber&#39;s plug  86  located at the bottom end of the threaded stem  78  is located between two flat discs  94  and  96 . In one example, the flat disc  94  and  96  are made of steel. The top flat disc  94  is located above the plumber&#39;s plug  86  under a spring pin  98  that is located under the pipe  70 , and the bottom flat disc  96  is located below the plumber&#39;s plug  86 . The bottom flat disc  96  is fixed to the bottom end of the threaded stem  78 , and the top flat disc  94  is not fixed to the threaded stem  78 . When the wing-nut handle  87  is rotated, the threaded stem  78  is rotated by turning the wing-nut handle  87 . The bottom flat disc  96  rotates and moves upwardly towards the top flat disc  94 . This force compresses the plumber&#39;s plug  86 , causing the plumber&#39;s plug  86  to expand in diameter. The wing-nut handle  87  can be turned into the opposite direction to lower the bottom flat disc  96  relative to the top flat disc  94 , removing the pressure and causing the plumber&#39;s plug  86  to reduce in diameter. 
     As the drain insert  30  is lifted, gravity causes the small portion  44  to telescope downwardly relative to the medium portion  42 . The small portion  44  does not separate from the medium portion  42  due to the engagement of the outwardly extending projection  58  of the small portion  44  and the inwardly extending projection  56  of the medium portion  42 . As the drain insert  30  is lifted more, gravity causes the medium portion  42  to telescope downwardly relative to the large portion  40 . The medium portion  42  does not separate from the large portion  40  due to the engagement of the outwardly extending projection  52  of the medium portion  42  and the inwardly extending projection  50  of the large portion  40 . The drain insert  30  is then in the extended position. 
     When the drain insert  30  is to be used, the drain basket  24  is removed, exposing the drain bowl  26 . The plumber&#39;s plug that corresponds to the size of the drain line  41  is attached to the lower end of the threaded stem  78 . The drain insert  30  is positioned over the drain bowl  26  and lowered into the drain bowl  26 . 
       FIG. 7  shows the drain insert  30  received in a 6″ drain line  41 . The plumber&#39;s plug  86  is secured to the bottom of the threaded stem  78 . The small portion  44 , the medium portion  42  and the large portion  40  have a diameter smaller than the diameter of the drain line  41 , and the portions  40 ,  42  and  44  can enter the drain line  41 , and the drain insert  30  is in the extended position. The outwardly extending projection  46  of the large portion  40  is larger than the diameter of the 6″ drain line  41 , preventing the drain insert  30  from falling through the drain line  41 . The outwardly extending portion  46  of the large portion  40  rests against and contacts the bottom surface  111  of the drain bowl  26 . In this position, the drain insert  30  is in the fully extended position. The wing-nut handle  87  is then turned to compress the plumber&#39;s plug  86  between the flat disks  94  and  96 , extending the diameter of the plumber&#39;s plug  86  and expanding the plumber&#39;s plug  86  against the wall of the drain line  41 , securing the drain insert  30  in the drain line  41 . 
       FIG. 8  shows the drain insert  30  received in a 4″ drain line  41  in a partially extended position. The plumber&#39;s plug  88  is secured to the bottom of the threaded stem  78 . The small portion  44  and the medium portion  42  have a diameter smaller than the diameter of the drain line  41 , and the portions  42  and  44  can enter the drain line  41 ; the large portion  40  is located in the drain bowl  26 . The projections  50  and  52  are larger than the diameter of the 4″ drain line  41 , preventing the drain insert  30  from falling through the drain line  41 . The inwardly extending portion  50  of the large portion  40  rests against and contacts the bottom surface  111  of the drain bowl  26 . In this position, the drain insert  30  is in the fully extended position. The wing-nut handle  87  is then turned to compress the plumber&#39;s plug  88  between the flat disks  94  and  96 , extending the diameter of the plumber&#39;s plug  88  and expanding the plumber&#39;s plug  88  against the wall of the drain line  41 , securing the drain insert  30  in the drain line  41 . 
       FIG. 9  shows the drain insert  30  received in a 3″ drain line  41 . The plumber&#39;s plug  90  is secured to the bottom of the threaded stem  78 . The small portion  44  has a diameter smaller than the diameter of the drain line  41 , and only the small portion  44  enters the drain line  41 . The medium portion  42  is biased into the hollow space of the large portion  40  and located in the drain bowl  26 . The projections  56  and  58  are larger than the diameter of the 3″ drain line  41 , preventing the drain insert  30  from falling through the drain line  41 . The inwardly extending portion  56  of the medium portion  42  rests against and contacts the bottom surface  111  of the drain bowl  26 . In this position, the drain insert  30  is partially contracted. The wing-nut handle  87  is then turned to compress the plumber&#39;s plug  90  between the flat disks  94  and  96 , extending the diameter of the plumber&#39;s plug  90  and expanding the plumber&#39;s plug  90  against the wall of the drain line  41 , securing the drain insert  30  in the drain line  41 . 
     Once the drain insert  30  is secured in the drain line  41 , a carry ring  100  is secured to the threaded stem  78  or the pipe  70 . The carry ring  100  is located at one end of the lanyard  34 , and the other end of the lanyard  34  is attached to a harness  36  that is worn by the worker  38  to restrain the worker  38 . 
       FIG. 10  illustrates a second example safety anchor. The safety anchor is a wall bracket  32 . In one example, the wall bracket  32  can sustain 200 pounds of weight to meet the OSHA fall prevention guidelines. The wall bracket  32  includes a first portion  200  and a second portion  202 . In one example, the first portion  200  and the second portion  202  are made of aluminum. The second portion  202  includes an insertable arm  204  that is receivable in a hollow receiving tube  206  of the first portion  200 . In one example, the insertable arm  204  has a substantially circular cross-section, and the receiving tube  206  has a substantially square cross-section. 
     As shown in  FIG. 11 , the first portion  200  includes the receiving tube  206 , a connecting arm  208  that is substantially perpendicular to the receiving tube  206 , and a pressure arm  210  that is substantially perpendicular to the connecting arm  208  and substantially parallel to the receiving tube  206 . The receiving tube  206  includes an aperture  216 . A gusset  212  is provided at the intersection of the receiving tube  206  and the connecting arm  208  to provide support. The pressure arm  210  is shorter than the receiving tube  206 , and a rubber pad  214  is positioned at an end of the pressure arm  210 . 
     As shown in  FIG. 12 , the second portion  202  includes an arm  218  that is substantially perpendicular to the insertable arm  204 . The arm  218  includes an aperture  220 , as described below. A gusset  222  is provided at the intersection of the insertable arm  204  and the arm  218  to provide support. The insertable arm  204  includes a plurality of apertures  224 . 
     In use, returning to  FIG. 10 , the wall bracket  32  is positioned such that the first portion  200  is located on an outside wall  226  of the parapet wall  28 , and the second portion  202  is located on an inside wall  228  of the parapet wall  28 . The insertable arm  204  is received in a hollow interior of the receiving tube  206 . The rubber pad  214  is positioned on the outside wall of the parapet wall  28 . A threaded eye bolt  236  is received in the aperture  220  of the second portion  202 , and the threaded eye bolt  236  is turned in a first direction to position a rubber pad  214  attached to the threaded eye bolt  236  against the inside wall  228  of the parapet wall  28 . 
     The aperture  216  of the first portion  200  is aligned with one of the apertures  224  of the second portion  202 , and a safety clasp  230  (shown in  FIG. 13 ) is received in the aligned apertures  216  and  220 . The safety clasp  230  includes a pin  232  having a groove  237  and a clasp  234  including a hook  239 . Once the pin  232  is received in the aligned apertures  216  and  220 , the hook  239  is received in the groove  237 , securing the safety clasp  230  in position. 
     The alignment of the apertures  216  and  220  provides for rough alignment of the wall bracket  32 . Returning to  FIG. 10 , the threaded eye bolt  236  provides for fine adjustment of the wall bracket  32 . A stainless steel band  240  is located around the portion of the arm  218  that includes the aperture  220 . A nut  242  is positioned on each side of the aperture  220 . The threaded eye bolt  236  includes a ball fit  246  at an end of the threaded eye bolt  236 . The threaded eye bolt  236  is received in an aperture  248  of a swivel portion  244 , and the ball fit  246  is received within the swivel portion  244 . The rubber pad  238  is located on the swivel portion  244 . The swivel portion  244  can swivel relative to the threaded eye bolt  236  to accommodate for any unevenness in the surface of the parapet wall  28 . A looped end  250  of the threaded eye bolt  236  is rotated to move the rubber pad  238  towards the parapet wall  28  to provide for fine adjustment of the wall bracket  32 . 
     Once the wall bracket  32  has been adjusted, the rubber pads  214  and  238  are positioned against the respective wall  226  and  228 , securing the wall bracket  32  to the parapet wall  28 . The force or pull is directly horizontal from an inside contact point of the eye bolt  236  to the inside wall  228  to an outside contact point of the rubber pad  214  to the outside wall  226 , ensuring that the wall bracket  32  does not slide or pivot away from the parapet wall  28  when a force is applied to the wall bracket  32 . 
     In use, the carry ring  100  attached to a lanyard  34  is attached to the looped end  250  of the threaded eye bolt  236 . The lanyard  34  is attached to a harness  36  worn by a worker  38  to restrain the worker  38 . 
     To remove the wall bracket  32 , the threaded eye bolt  236  is loosened and turned in an opposing second direction, removing the force of the rubber pad  238  against the inside wall  228  of the parapet wall  28 . The safety clasp  230  can then be removed to allow the first portion  200  and the second portion  202  to separate and be removed from the parapet wall  28 . 
       FIG. 14  illustrates a third example safety anchor. The safety anchor is a wall bracket  334 . In one example, the wall bracket  334  can sustain 5000 pounds of weight to meet the OSHA fall arrest guidelines. The wall bracket  334  includes a first portion  301  and a second portion  302 . In one example, the first portion  301  and the second portion  302  are made of aluminum. The second portion  302  includes an insertable arm  304  that is receivable in a hollow receiving tube  306  of the first portion  301 . In one example, the insertable arm  304  and the receiving tube  306  have a substantially square cross-section. 
     As shown in  FIG. 15 , the first portion  301  includes the receiving tube  306 , a connecting arm  308  that is substantially perpendicular to the receiving tube  306 , and a pressure arm  310  that is substantially perpendicular to the connecting arm  308  and substantially parallel to the receiving tube  306 . The receiving tube  306  includes an aperture  316 . A gusset  312  is provided at the intersection of the receiving tube  306  and the connecting arm  308  to provide support. The gusset  312  extends the width of the wall bracket  334 . That is, the gusset  312  has a width that is approximately equal to the width of the connecting arm  308 . The pressure arm  310  is shorter than the receiving tube  306 , and a rubber pad  314  is positioned at an end of a horizontal planar portion  315  on an end of the pressure arm  310 . A gusset  317  is attached at the intersection of the pressure arm  310  and the horizontal planar portion  315 . 
     As shown in  FIG. 16 , the second portion  302  includes an arm  318  that is substantially perpendicular to the insertable arm  304 . The arm  318  includes an aperture  320 , as described below. A gusset  322  is provided at the intersection of the insertable arm  304  and the arm  318  to provide support. The gusset  322  extends the width of the wall bracket  334 . That is, the gusset  322  has a width that is approximately equal to the width of the arm  318 . The insertable arm  304  includes a plurality of apertures  324 . 
     In use, returning to  FIG. 14 , the wall bracket  334  is positioned such that the first portion  301  is located on an outside wall  226  of the parapet wall  28 , and the second portion  302  is located on an inside wall  228  of the parapet wall  28 . The insertable arm  304  is received in a hollow interior of the receiving tube  306 . The rubber pad  314  is positioned on the outside wall of the parapet wall  28 . A threaded eye bolt  336  (shown in  FIG. 17 ) including a rubber pad  338  is received in the aperture  320  of the second portion  302 , and the threaded eye bolt  336  is turned in a first direction to position the rubber pad  338  against the inside wall  228  of the parapet wall  28 . The rubber pad  338  is positioned on a circular portion  339 . 
     The aperture  316  of the first portion  301  is aligned with one of the apertures  324  of the second portion  302 , and a hitch pin  330  (shown in  FIG. 18 ) is received in the aligned apertures  316  and  320 . 
     The alignment of the apertures  316  and  324  provides for rough alignment of the wall bracket  334 . Returning to  FIG. 17 , the threaded eye bolt  336  provides for fine adjustment of the wall bracket  334 . A stainless steel band  340  is located around the portion of the arm  318  that includes the aperture  324 . A nut  342  is positioned on each side of the aperture  320 . The threaded eye bolt  336  includes a ball fit  346  at the end of the threaded eye bolt  336 . The threaded eye bolt  336  is received in an aperture  348  of a swivel portion  344 , and the ball fit  346  is received within the swivel portion  344 . The rubber pad  338  is located on the swivel portion  344 . The swivel portion  344  can swivel relative to the threaded eye bolt  336  to accommodate for any unevenness in the surface of the parapet wall  28 . A looped end  350  of the threaded eye bolt  336  is rotated to move the rubber pad  338  towards the parapet wall  28  to provide for fine adjustment of the wall bracket  334 . 
     Once the wall bracket  334  has been adjusted, the rubber pads  314  and  338  are positioned against the respective wall  226  and  228 , securing the wall bracket  334  to the parapet wall  28 . The force or pull is directly horizontal from the inside contact point of the eye bolt  336  to the inside wall  228  to an outside contact point of the rubber pad  314  to an outside wall  226 , ensuring that the wall bracket  334  does not side or pivot away from the parapet wall  28  when a force is applied to the wall bracket  334 . 
     In use, the carry ring  100  attached to a lanyard  34  is attached to the looped end  350  of the threaded eye bolt  336 . The lanyard  34  is attached to a harness  36  worn by a worker  38  to restrain the worker  38 . 
     To remove the wall bracket  334 , the threaded eye bolt  336  is loosened and turned in an opposing second direction, removing the force of the rubber pad  338  against the inside wall  228  of the parapet wall  28 . The hitch pin  330  can then be removed to allow the first portion  301  and the second portion  302  to separate and be removed from the parapet wall  28 . 
     The foregoing description is only exemplary of the principles of the invention. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, so that one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.

Technology Classification (CPC): 4