Patent Publication Number: US-2010126801-A1

Title: Fall arrest apparatus

Description:
FIELD OF INVENTION 
     The present invention relates to a fall arrest apparatus for building construction. 
     BACKGROUND OF THE INVENTION 
     In typical building construction, workers are required to operate at elevations above ground level. Accidental falls from these elevations can result in severe injury or death. In order to protect workers from such falls, a fall arrest apparatus can be utilized 
     A number of fall arrest apparatuses are known in the prior art that protect workers from falls at a worksite. One type of fall arrest apparatus comprises a modular system where the height of the apparatus may be incrementally extended as the height of the building advances. This type of apparatus typically contains one or more fixed anchor loops at the top of the apparatus A worker attaches a lanyard to an anchor loop and to a safety harness worn by the worker. The worker may then safely operate in a work environment defined by a radius about the top of the apparatus equal to the length of the lanyard. While this type of apparatus provides the advantage of incremental height extension as the height of the building advances, it has the disadvantage of limiting the worker&#39;s safe work environment to a small radius about the top of the apparatus. 
     Another type of fall arrest apparatus comprises a cable mounted to the side of a building via mounting brackets. A worker attaches a lanyard to the cable and to a safety harness worn by the worker. The worker may then safely operate in a work environment defined by a cylinder along the length of the cable with a radius equal to the length of the lanyard. While this type of apparatus provides the advantage of a larger safe work environment, it has the disadvantage of requiring the apparatus to be remounted to the building whenever the building height advances during construction. 
     SUMMARY OF THE INVENTION 
     It is an objective of the present invention to provide a fall arrest apparatus that overcomes at least some of the disadvantages in the prior art. 
     According to one aspect of the invention there is provided a fall arrest apparatus for building construction comprising:
         (a) a base;   (b) a support column comprising one or more interconnecting stanchions, the support column having a proximal end mounted to the base;   (c) a boom mast having a proximal end rotatably coupled to a distal end of the support column;   (d) a boom operable to support a load, the boom having a proximal end coupled to the boom mast such that a distal end of the boom extends away from the boom mast; and   (e) a boom support assembly coupled to the boom and the boom mast such that at least a portion of the load is borne by the boom support assembly when the load is applied to the boom.       

     The base may comprise a plate for mounting to a support surface, and a sleeve mounted to the plate and adapted to accept the proximal end of the support column. 
     The boom may further comprises a fastener mounted to the distal end of the boom, the fastener operable to receive the load. The fastener may be an anchor loop. 
     The boom may also further comprise a track along the length of the boom, the track operable to receive the load and translate the load along the length of the boom. The track may comprise a stanchion and at least one guide rail spaced from and extending parallel to the stanchion. 
     The apparatus may be defined such that the proximal end of the boom is coupled to the proximal end of the boom mast, and the boom support assembly comprises a guy-wire coupled to the distal end of the boom and a distal end of the boom mast. The boom support assembly may further comprises a winch mounted to the boom mast, the winch receiving the guy-wire extending from the distal end of the boom mast. 
     The apparatus may be defined such that the proximal end of the boom is coupled to a distal end of the boom mast, and the boom support assembly comprises a stanchion coupled to the boom and the proximal end of the boom mast. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1   a  is a side view of a fall arrest apparatus according to one embodiment of the invention. 
         FIG. 1   b  is a side view of the fall arrest apparatus shown in  FIG. 1  installed at a worksite. 
         FIG. 2  is a perspective view of a base of the fall arrest apparatus shown in  FIG. 1 , shown in isolation. 
         FIG. 3  is a side view of a stanchion of the fall arrest apparatus shown in  FIG. 1 , shown in isolation. 
         FIG. 4  is a side view of a boom mast and a winch of the fall arrest apparatus shown in  FIG. 1 , shown in isolation. 
         FIG. 5   a  is a top view of a boom of the fall arrest apparatus shown in  FIG. 1 , shown in isolation. 
         FIG. 5   b  is a side view of the boom of a fall arrest apparatus according to another embodiment of the invention, shown in isolation. 
         FIG. 6  is a side view of a fall arrest apparatus according to another embodiment of the invention. 
         FIG. 7  is a side view of a fall arrest apparatus according to another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The embodiments described herein relate to a fall arrest apparatus for building construction. Particularly, the embodiments relate to an apparatus for protecting a worker from falling at a worksite while at the same time permitting the worker to move freely about the worksite. 
     Referring to  FIG. 1a , a first embodiment of the fall arrest apparatus is shown generally as item I and comprises the following major components: a base  2 , a support column  3 , a boom mast  4 , a boom  5 , and a boom support assembly  6 . 
     Referring to  FIG. 2 , the base  2  operates to support the other components of the apparatus  1 . During installation, the base  2  is mounted to a support surface (not shown), such as a sub floor of a building under construction. The base  2  comprises a plate  20  and a tubular sleeve  21  mounted to the plate  20  such that the longitudinal axis of the sleeve  21  is perpendicular to the top surface of the plate  20 . The plate  20  comprises eight mounting holes  22  about the perimeter of the plate  20  permitting mounting bolts (not shown) to secure the plate  20  to an underlying support surface. The sleeve  21  is sized to receive the proximal end of the support column  3  such that the longitudinal axis of the support column  3  is in axial alignment with the longitudinal axis of the sleeve  21 . The sleeve  21  also comprises four mounting holes  23  permitting mounting bolts (not shown) to secure the support column  3  to the base  2  by applying pressure against the outer surface of the support column  3 . During assembly of the apparatus  1 , the support column  3  is inserted into the sleeve  31  such that the proximal end of the support column  3  rests against the top surface of the plate  20 , directing the weight of the apparatus  1  through the plate  20  to the underlying support surface. 
     In alternative embodiments, the base  2  may comprise other mechanical components and configurations known to one skilled in the art for supporting the apparatus  1 . For example, the base  2  may be of sufficient weight such that it is not necessary to mount the base  2  to a supporting surface. 
     Referring to  FIG. 1   a , the support column  3  has a proximal end mounted to the base  2  and a distal end rotatably coupled to the boom mast  4 . The support column  3  comprises a series of interconnecting stanchions  8 . Referring to  FIG. 3 , each stanchion  8  comprises an outer tube  30  and an inner tube  31 . The proximal end of the inner tube  31  is mounted inside of the outer tube  30  by means of two mounting bolts  35 , and the distal end of the inner tube  31  extends out of the distal end of the outer tube  30 . The inner tube  30  extends inside of the outer tube  30  a longitudinal distance of approximately sixteen inches. During assembly of the apparatus  1 , stanchions  8  are stacked in series such that the inner tube  31  of a first stanchion  8  is received by the outer tube  30  of a second stanchion  8  stacked on top of the first stanchion  8 . The first and second stanchions  8  are secured to one another by a cotter pin (not shown) inserted through mounting holes  32  in the outer tube  30  of the second stanchion  8  and mounting holes  33  of the inner tube  31  of the first stanchion  8 , such that the cotter pin passes through both the first and second stanchions  8 . Successive stanchions  8  are stacked in a similar manner. 
     Each stanchion  8  also comprises four anchor loops  34  mounted to the outer surface of the outer tube  30 . During assembly of the apparatus  1 , supporting cables can be attached to the anchor loops  34  and to support structures on the worksite in order to provide additional support to the apparatus  1 . 
     Referring to  FIG. 4 , the boom mast  4  comprises: a stanchion  50 , a pulley  51 , a boom mount  52  and a winch mount  53 . The stanchion  50  has a distal end mounted to the pulley  51  and a proximal end rotatably coupled to the distal end of the support column  3 . The longitudinal axis of the stanchion  50  is in axial alignment with the longitudinal axis of the support column  3 , permitting the stanchion  50  to rotate a full 360 degrees about the support column  3 . The proximal end of the stanchion  50  comprises a hollow tubular void sized to receive the distal end of the support column  3  inside of the stanchion  50  such that the stanchion  50  is rotatably slidable about the distal end of the support column  3 . A bushing is mounted inside the proximal end of the stanchion  50  to reduce rotational friction between the stanchion  50  and the support column  3 . 
     The pulley  51  is mounted to the distal end of the stanchion  50  and is operable to receive a guy-wire  10  forming part of the boom support assembly  6  (described below). The boom mount  52  and the winch mount  54  are mounted to opposite sides of the outer surface of the proximal end of the stanchion  50 . The boom mount  52  comprises two flanges each having two mounting holes  53  for mounting to the boom  5  (described below). The winch mount  54  is a rectangular frame mounted to a winch  9  (described below). 
     Referring to  FIG. 1   a , the boom S has a proximal end mounted to the boom mast  4  by the boom mount  52  and a distal end coupled to a guy wire  10  (described below). The boom  5  extends out from the boom mast  4  such that the longitudinal axis of the boom  5  is perpendicular to the longitudinal axis of the boom mast  4 . In alternative embodiments, the boom  5  may extend in any direction from the boom mast  4 . 
     Referring to  FIG. 5   a , the boom  5  comprises a track consisting of a stanchion  60  and two retaining rails  61  spaced from and extending generally parallel to the stanchion  60 . The proximal end of the stanchion  60  comprises two mounting holes  62  running through the stanchion  60 . The spacing between the mounting holes  62  is identical to that of the mounting holes  53  of the boom mount  52 , permitting the boom  5  to be bolted to the boom mast  4 . The distal end of the stanchion  60  comprises an anchor loop  63  for attachment of the guy-wire  10  (described below). 
     The retaining rails  61  are mounted to opposite sides of the outer surface of the stanchion  60 . In operation, a lanyard is attached around the stanchion  60  and to a safety harness worn by a worker. The retaining rails  61  permit a worker to move the lanyard along the length of the stanchion  60  while restricting the lanyard from moving off of the distal end of the boom  5  such that the lanyard is detached from the stanchion  60 . 
     In alternative embodiments, the track of the base  2  may comprise other mechanical components and configurations known to one skilled in the art operable to receive load and translate the load along the length of the boom  5 , for example, a track and rollered trolley system. 
     Referring to  FIG. 5   b , an alternative embodiment of a boom  65  comprises a stanchion  66  having mounting holes  67  and an anchor loop  68 , identical to those described in boom  5 . In addition, the boom  65  comprises an anchor loop  69  mounted to the distal end of the stanchion  66  for accepting a lanyard. In the alternative, any fastener operable to receive a load may be utilized in place of anchor loop  69 . 
     Referring to  FIG. 1   a , the boom support assembly  6  operates to support the boom  5  when a load is applied to the boom  5 . The boom support assembly  6  comprises a winch  9  and the guy-wire  10 . The winch  9  is mounted to the winch mount  54 . The guy-wire  10  is attached to the anchor loop  63  on the distal end of the boom  5 , extends over the pulley  51  of the boom mast  4 , and is received by the winch  9 . The winch  9  is operable to tighten and loosen the guy-wire  10 . It is utilized to place the guy-wire  10  in tension, thereby, transferring a portion of the load on the boom  5  through the guy-wire  10 , through the boom mast  4  and support column  3 , through the base  2 , and to the support surface. 
     In operation, the apparatus  1  is transported to a worksite in pie-assembled components comprising: the base  2 , the stanchions  8 , the boom mast  4  attached to the winch  9 , the boom  5 , the guy-wire  10 , and the mounting bolts and cotter pins. The base  2  is mounted to a support surface by bolting the plate  20  of the base  2  to the support surface. The base  2  is typically located on the worksite about the area where the workers will be operating above ground level. 
     The proximal end of a first stanchion  8  is inserted into and bolted to the sleeve  21  of the base  2 . If additional support is required, support cables are attached to a support structure on the worksite and to the anchor loops  34  of the stanchion  8 . If additional height is required, the outer tube  30  of a second stanchion  8  is placed over the inner tube  31  of the first stanchion  31 . The mounting holes  33  of the first stanchion  8  and the mounting holes  32  of the second stanchion  8  are aligned, and a cotter pin is inserted through the mounting holes  32 ,  33 . This process of stacking and securing stanchions  8  is repeated until a desired height is achieved. 
     The boom  5  is then bolted to the boom mast  4  by aligning the mounting holes  62  of the boom  5  with the mounting holes  53  of the boom mast  4  and inserting bolts therethrough. The guy wire  10  is attached to the anchor loop  63  of the boom  5 , extended over the pulley  51  of the boom mast  4 , and received by the winch  9  of the boom support assembly  6 . The winch  9  is then operated to place the guy-wire  10  in sufficient tension to bear a portion of a load placed on the boom  5 . The boom  5  and boom mast  4  are then elevated and the proximal end of the stanchion  50  of the boom mast  4  is placed over the distal end of the support column  3 , such that the boom mast  4 , boom  5  and boom mount assembly  6  are rotatable about the support column  3 . 
     A lanyard is attached to the stanchion  60  of the boom  5  and to a harness worn by a worker serving as the load At this point, the worker can safely work above ground level while being free to move along the length of the boom  5  and in a 360 degree path about the support column  3 . As the worker moves along the length of the boom  5 , the lanyard slidably translates accordingly along the stanchion  60  of the boom  5 . As the worker moves in an angular direction about the longitudinal axis of the support column  3 , the boom mast  4  and boom  5  rotate accordingly about the same axis. 
     In the alternative, the boom mast  4  and boom  5  are mounted on the support column in a different sequence. Only one bolt is placed through the boom S and boom mount  53  such that the boom  5  can rotate about the axis of the bolt. The boom  5  is positioned such that the longitudinal axis of the boom  5  is parallel to the longitudinal axis of the boom mast  4 . The guy wire  10  is then attached to the anchor loop  63  of the boom  5 , extended over the pulley  51  of the boom mast  4 , and received by the winch  9  of the boom support assembly  6 . The boom  5  and boom mast  4  are then elevated and the proximal end of the stanchion  50  of the boom mast  4  is placed over the distal end of the support column  3 , such that the boom mast  4 , boom  5  and boom mount assembly  6  are rotatable about the support column  3 . The winch  9  is then utilized to rotate the boom  5  about the bolt until the longitudinal axis of the boom  5  is perpendicular with the longitudinal axis of the boom mast  4 . A second bolt is placed through the boom  5  and boom mount  53  such that the position of the boom  5  is fixed with respect to the boom mast  4 . The winch  9  is then operated to place the guy-wire  10  in sufficient tension to support a load placed on the boom  5 . 
     Referring to  FIG. 6 , an alternative embodiment of a fall arrest apparatus  70  comprises a simplified boom support assembly  76  consisting of a single supporting stanchion. The apparatus  70  also comprises a base  72 , support column  73 , a boom mast  74 , and a boom  75 . The base  72  and support column  73  are identical to those described for apparatus  1 . The boom mast  74  is identical to boom mast  4 , except that boom mast  74  does not comprise a pulley  51  or a winch mount  54 . The boom  75  is identical to boom  5 , except that the boom  75  does not comprise an anchor loop  63 . The boom support assembly  76  consists of a single supporting stanchion that is bolted to the distal end of the boom mast  74  and the distal end of the boom  75 . This embodiment offers a more simplistic boom support assembly  76  as compared to the guy-wire  10 , pulley  51  and winch  9  disclosed in apparatus  1 . 
     Referring to  FIG. 7 , an alternative embodiment of a fall arrest apparatus  80  comprises another simplified boom support assembly  86  consisting of a single supporting stanchion. The apparatus  80  also comprises a base  82 , support column  83 , a boom mast  84 , and a boom  85 , identical to those described for apparatus  70 , except that the proximal end of the boom  85  is mounted to the distal end of boom mast  84 , and the boom support assembly  86  is mounted to the distal end of the boom  85  and the proximal end of the boom mast  84 . This embodiment also offers a more simplistic boom support assembly  86  as compared to the guy-wire  10 , pulley  51  and winch  9  disclosed in apparatus  1 . 
     The embodiments of the present invention described above are merely illustrative and are not to be construed as exhaustive.