Patent Publication Number: US-11021847-B2

Title: Bell hole box

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     None. 
     FIELD OF THE INVENTION 
     This invention relates to a bell hole box that may be installed at some distance below a surface of the Earth to provide a safe and comfortable space within which people may work. 
     BACKGROUND OF THE INVENTION 
     Devices known generally as trench boxes or trench shoring assemblies have been known in the field of pipeline repair and construction for years. Generally, such devices are placed into the ground to protect workers from unstable Earthen walls that may be susceptible to collapse and thus injure a human worker who may suffer an injury were it not for the vertical walls of the trench box, within which a worker is required to work. However, such devices are not without their share of limitations. Known trench boxes are generally relatively narrow and permit only certain, limited tasks to be performed within the box confines, while also limiting the number of workers who can work within the confines of the box. Furthermore, due to current designs of trench boxes, a large pipe that passes through the trench box may contact and injure workers since traditional straight walls of a trench box provide no space for a worker to reside in the event of a pipe that shifts or moves toward either wall. 
     What is needed then is a device and method that does not suffer from the above limitations. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     In one embodiment of the present teachings, an apparatus for protecting construction workers working below a top surface of the Earth may include a first box wall, a second box wall, a first spreader positioned at 90 degrees to at least one structural side panel of first box wall and second box wall, and a second spreader positioned at 90 degrees to at least one structural side panel of first box wall and second box wall. The apparatus may further include a first spreader receiver assembly that defines a hollow cavity and is mounted to the first box wall, a second spreader receiver assembly that defines a hollow cavity and is mounted to the second box wall. At least a portion of the first spreader assembly occupies the hollow cavity of the first spreader receiver assembly and the hollow cavity of the second spreader receiver assembly. The apparatus may further include a third spreader receiver assembly that defines a hollow cavity and is mounted to the first box wall, and a fourth spreader receiver assembly that defines a hollow cavity and is mounted to the second box wall. At least a portion of the second spreader assembly may occupies the hollow cavity of the third spreader receiver assembly and the hollow cavity of the fourth spreader receiver assembly. A first spreader assembly top plate may be attached to the first spreader assembly. The first spreader assembly top plate is connected to the first box wall and the second box wall. A second spreader assembly top plate may be attached to the second spreader assembly. The second spreader assembly top plate is connected to the first box wall and the second box wall. A ladder may be attached to an interior surface of the first box wall to permit a person to easily enter and exit the apparatus. 
     A feature of the first embodiment may be that the first box wall has a first longitudinal end and a second longitudinal end, and the second box wall has a first longitudinal end and a second longitudinal end, such that a first distance between the first longitudinal end of the first box wall and the first longitudinal end of the second box, and a second distance between the second longitudinal end of the first box wall and the second longitudinal end of the second box wall, are both less than a midpoint distance between a midpoint of the first box wall and a midpoint of the second box wall. 
     In a second embodiment of the present teachings, an apparatus for protecting construction workers working below a top surface of the Earth may include a first box wall constructed generally of five straight panels, a second box wall constructed generally of five straight panels, a first spreader connected to one of the five straight panels of the first box wall and one of the five straight panels of the second box wall, a second spreader connected to one of the five straight panels of the first box wall and one of the five straight panels of the second box wall, a plurality of guard posts connected to a top frame rail of the first box wall, and a plurality of guard posts connected to a top frame rail of the second box wall. A ladder may be attached to an interior surface of the first box wall, and a top of the ladder may pivot to permit a bottom of the ladder to move away from the first box wall. An extension device may be installed on the ladder to permit the bottom of the ladder to be movable to a swung-out position away from the first box wall. A locking mechanism built into the extension device locks the bottom of the ladder in an extended position away from the first arcuate side wall. The five straight panels of the first box wall are further comprised of two coplanar panels at opposite ends of the first box wall, and the five straight panels of the second box wall are further comprised of two coplanar panels at opposite ends of the second box wall. 
     With respect to the second embodiment, a first spreader receiver assembly may define a hollow cavity, and a second spreader receiver assembly may define a hollow cavity, at least a portion of the first spreader occupies the hollow cavity of the first spreader receiver assembly and the hollow cavity of the second spreader receiver assembly. A third spreader receiver assembly may define a hollow cavity, and a fourth spreader receiver assembly may define a hollow cavity, and at least a portion of the second spreader occupies the hollow cavity of the third spreader receiver assembly and the hollow cavity of the fourth spreader receiver assembly. 
     In the second embodiment, the first spreader receiver assembly and the third spreader receiver assembly are mounted to the first box wall, and the second spreader receiver assembly and the fourth spreader receiver assembly are mounted to the second box wall. A first spreader receiver assembly pin may completely pass through the first spreader receiver assembly and the first spreader, a second spreader receiver assembly pin may completely pass through the second spreader receiver assembly and the first spreader, a third spreader receiver assembly pin may completely pass through the third spreader receiver assembly and the second spreader, and a fourth spreader receiver assembly pin may completely pass through the fourth spreader receiver assembly and the second spreader. Three of the five straight panels of the first box wall, and three of the five straight panels of the second box wall, and the first spreader, and the second spreader, form an eight-sided structure, for example in a top view. 
     In a third embodiment of the present teachings, an apparatus for protecting construction workers working below a top surface of the Earth may include a first arcuate side wall, a second arcuate side wall, a first spreader connected to the first arcuate side wall and the second arcuate side wall, a second spreader connected to the first arcuate side wall and the second arcuate side wall, a plurality of guard posts connected to a top frame rail of the first arcuate side wall, and a plurality of guard posts connected to a top frame rail of the second arcuate side wall. A plurality of chains may be connected to the guard posts and spanning between the guard posts. The first arcuate side wall and the second arcuate side wall may be mirror images of each other, and the first arcuate side wall and the second arcuate side wall lie partially between the first spreader and the second spreader. The apparatus may further include a first spreader receiver assembly defining a hollow cavity, and a second spreader receiver assembly defining a hollow cavity, and at least a portion of the first spreader occupies the hollow cavity of the first spreader receiver assembly and the hollow cavity of the second spreader receiver assembly. A third spreader receiver assembly may define a hollow cavity, and a fourth spreader receiver assembly may define a hollow cavity, and at least a portion of the second spreader occupies the hollow cavity of the third spreader receiver assembly and the hollow cavity of the fourth spreader receiver assembly. The first spreader receiver assembly and the third spreader receiver assembly are mounted to the first side wall, and the second spreader receiver assembly and the fourth spreader receiver assembly are mounted to the second side wall. 
     The third embodiment may further include a first spreader receiver assembly pin that completely passes through the first spreader receiver assembly and the first spreader, a second spreader receiver assembly pin that completely passes through the second spreader receiver assembly and the first spreader, a third spreader receiver assembly pin that completely passes through the third spreader receiver assembly and the second spreader, and a fourth spreader receiver assembly pin that completely passes through the fourth spreader receiver assembly and the second spreader. In a top view, the first spreader, the second spreader, the first arcuate side wall and the second arcuate side wall form a four-sided structure with two curved sides and two straight sides. The apparatus may further include a pointed tip along a bottom surface of the first arcuate side wall and the second arcuate side wall for engaging an Earthen surface. A ladder may be attached to an interior surface of the first arcuate side wall. The top of the ladder may pivot to permit a bottom of the ladder to move away from the first arcuate side wall, and an extension device may be connected to the ladder to permit the bottom of the ladder to be movable to a swung-out position away from the first arcuate side wall. A locking mechanism may be built into the extension device to lock the ladder in an extended position away from the first arcuate side wall. 
     In a fourth embodiment of an apparatus for protecting people working below a surface of the Earth may include a bottom bell hole box residing within a hole, and a top bell hole box residing on top of the bottom bell hole box. The apparatus may further include a protruding wedge portion having a slanted surface relative to a vertical surface, the protruding wedge portion protruding from a bottom surface of the top bell hole box, and a tapered surface residing around the top of the bottom bell hole box, such that the slanted surface resides against the tapered surface. The bottom bell hole box may further include a vertical side support frame, such that the protruding wedge portion of the top bell hole box resides next to the vertical side support frame. The protruding wedge portion of the top bell hole box resides against the vertical side support frame. A plurality of posts may protrude from a top of the top bell hole box, and a plurality of safety chains connected between the plurality of posts. A first ladder attached to an interior surface of the bottom bell hole box. T top of the first ladder pivots to permit a bottom of the first ladder to move away from the interior surface of the bottom bell hole box. An extension device may be mounted to the bottom of the first ladder to lock the first ladder in an extended positon away from the interior wall, yet the extension device may remain fastened to the interior wall. A second ladder may be attached to an interior surface of the top bell hole box, directly above the first ladder to facilitate climbing up or down both ladders. A plurality of guard posts may protruding from a top surface of the top bell hole box. Safety chains may be draped or connect to and between the plurality of guard posts. The walls of the bottom bell hole box and the top bell hole box may be arcuate, or the walls of the bottom bell hole box and the top bell hole box may be made of linear sections to form a working space within the bottom bell hole box and the top bell hole box. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present invention and benefits thereof may be acquired by referring to the follow description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a perspective view of a bell hole box in accordance with the present teachings; 
         FIG. 2  is a perspective view of a wall of a bell hole box in accordance with the present teachings; 
         FIG. 3  is an enlarged bottom view of a portion of a top wall area of a bell hole box in accordance with the present teachings; 
         FIG. 4  is a perspective view of a wall of a bell hole box in accordance with the present teachings; 
         FIG. 5  is an enlarged view of a top wall area of a bell hole box in accordance with the present teachings; 
         FIG. 6  is a perspective view of a wall of a bell hole box depicting a location of a connective joint receptacle with an adjacent wall in accordance with the present teachings; 
         FIG. 7  is an enlarged view of a connective joint receptacle in accordance with the present teachings; 
         FIG. 8  is an enlarged view of a connective joint receptacle in accordance with the present teachings; 
         FIG. 9  is a view of a connective wall of a bell hole box in accordance with the present teachings; 
         FIG. 10  is a perspective view of a receiver spreader pin in accordance with the present teachings; 
         FIG. 11  is a perspective view of a hitch pin with tether and ring in accordance with the present teachings; 
         FIG. 12  is a hoist ring in accordance with the present teachings; 
         FIG. 13  is a guard post in accordance with the present teachings; 
         FIG. 14  is a view of side panels used to manufacture a spreader receiver assembly; 
         FIG. 15  is a view of a front panel used to manufacture a spreader receiver assembly; 
         FIG. 16  is a perspective view of another embodiment of a bell hole box having arcuate sides; 
         FIG. 17  is an enlarged view of a bottom portion of an arcuate side wall of bell hole box; 
         FIG. 18  is an enlarged view of a top portion of an arcuate side wall of bell hole box; 
         FIG. 19  is a perspective view of a bell hole box with arcuate side walls; 
         FIG. 20  is an enlarged view of a ladder area of bell hole box with arcuate side walls; 
         FIG. 21  is a top view of a bell hole box with arcuate side walls; 
         FIG. 22  is a perspective view of a first bell hole box stacked on top of a second bell hole box; 
         FIG. 23  is an enlarged view of a junction location where a first bell hole box stacks on top of a second bell hole box; 
         FIG. 24  is an enlarged view of a junction of a first bell hole box stacked on top of a second bell hole box; 
         FIG. 25  is an enlarged view of a junction of a first bell hole box stacked on top of a second bell hole box; 
         FIG. 26  is an enlarged view of an ingress and egress location of bell hole box; 
         FIG. 27  is a perspective view of a first bell hole box stacked on top of a second bell hole box depicting an example location of ladders for ingress and egress; 
         FIG. 28  is an enlarged view of an upper location of an upper bell hole box when the upper and first bell hole box is stacked on top of a lower and second bell hole box; 
         FIG. 29  is an enlarged view of an upper location of an upper bell hole box when the upper and first bell hole box is stacked on top of a lower and second bell hole box; 
         FIG. 30  is an enlarged view of a junction of a first bell hole box when stacked upon a second bell hole box, and depicting a location of multiple ladders, with holes for railing posts or guard posts; 
         FIG. 31  is a an enlarged view of a junction of a first bell hole box when stacked upon a second bell hole box, and depicting a location of multiple ladders, with safety chains installed between railing posts or guard posts; 
         FIG. 32  is a top view of a first bell hole box stacked on top of a second bell hole box depicting example locations for multiple ladders in a stacked configuration; 
         FIG. 33  is a perspective view of a ladder in its near-installed position next to an interior surface of a wall of a bell hole box; 
         FIG. 34  is a perspective view of a ladder in its near-installed position next to an interior surface of a wall of a bell hole box, the ladder exhibiting example linkages used mount the ladder to the interior support structure of the bell hole box; 
         FIG. 35  is a perspective view of a ladder that is mountable to the interior support structure of the bell hole box; 
         FIG. 36  is a perspective view of a ladder that is mountable to the interior support structure of the bell hole box; 
         FIG. 37  is a perspective view of a ladder that is mountable to the interior support structure of the bell hole box; and 
         FIG. 38  is a perspective view of a ladder that is mountable to the interior support structure of the bell hole box. 
     
    
    
     DETAILED DESCRIPTION 
     Turning now to the detailed description of the preferred arrangement or arrangements of the present invention, presented connection with  FIGS. 1-38 , it should be understood that the inventive features and concepts may be manifested in other arrangements and that the scope of the invention is not limited to the embodiments described or illustrated. The scope of the invention is intended only to be limited by the scope of the claims that follow. 
       FIG. 1  depicts a bell hole box  10  permitting passage of a pipeline  11  (see  FIG. 32 ) therethrough having major components of a first box wall  12 , a second box wall  14 , a first spreader  16 , and a second spreader  18 . The material of bell hole box  10  may be steel, aluminum, metal alloy, or suitable composite. Each box wall  12 ,  14  may be equipped with a spreader receiver assembly  20 ,  22  to receive or facilitate connection of first box wall  12  and second box wall  14  with first spreader  16 . Although not depicted in  FIG. 1 , connection of first box wall  12  and second box wall  14  may also be facilitated using a spreader receiver assembly for each of first spreader  16  and second spreader  18  on first box wall  12 , with each of first spreader  16  and second spreader  18  being received into a spreader receiver assembly on first box wall  12 . 
       FIG. 1  also depicts numerous representative sections of a safety chain  28  that may be strung between and also connected to guard posts. As an example, one end of safety chain  28  may be connected to guard post  24  and an opposite end of safety chain  28  may be connected to guard post  24 . Guard posts  28  may be inserted into holes  30  ( FIG. 2 ) around a first box wall top surface  32  and a second box wall top surface  34 . By inserting guard posts into holes  30 , guard posts are held securely in place when bell hole box  10  is placed into service below a surface of Earth. For example, bell hole box  10  may be placed into the ground or Earth for use in its service position such that first box wall top surface  32  and second box wall top surface  34  are at the same level, or nearly at the same level, as a surface of Earth adjacent bell hole box  10 . In such a position, people walking around a perimeter of bell hole box  10  will be protected from falling into an interior volume or space of bell hole box  10 . Guard posts such as guard posts  24 ,  24  may be inserted along an entire top surface  32  of first box wall  12  and an entire top surface  34  of second box wall  14 . 
     With continued reference to  FIG. 1 , in assembly of bell hole box  10 , first spreader  16  may be lifted with hoist ring  36  and hoist ring  38  and inserted into spreader receiver assembly  20  on second box wall  14  and a corresponding spreader receiver assembly on first box wall  12 . Similarly, second spreader  18  may be lifted with hoist ring  40  and hoist ring  42  and inserted into spreader receiver assembly  22  on second box wall  14  and a corresponding spreader receiver assembly on first box wall  12 . Hoist rings  36 ,  38 ,  40 ,  42  may have threaded shafts and screw into their corresponding spreader  16 ,  18  as depicted in  FIG. 1 . It is important to note that one or more ladders  160  depicted in  FIGS. 16, 19, 22, 27 and 32  may be mounted into, adapted into or otherwise installed into, in the same or similar way or position, bell hole box  10  depicted in  FIG. 1 , which does not specifically depict a ladder. 
       FIG. 2  depicts second box wall  14  in an upright position with numerous holes  30  located in and along second box wall top surface  34 . Holes  30  are for insertion of, and for securing, guard posts  24  as depicted in a secured position in  FIG. 1 .  FIG. 13  is an enlarged view of guard post  24  and further depicts chain connector  44 , which is used to connect safety chain  28  between successive guard posts  24 . Guard post  28  also has at one end a guard post stop  46 , which has a diameter larger than a diameter of any hole  30 , and functions to stop the guard post  24  from going too far into either first box wall top surface  32  or second box wall top surface  34 . Guard posts  28  are relatively easy to insert and remove to facilitate constructing and de-constructing bell hole box  10 . Continuing with  FIG. 2 , second box wall  14  may be a welded structure that generally has five major, separate straight portions  48 ,  50 ,  52 ,  54 ,  56 , which may also be referred to as linear. 
       FIG. 3  is an enlarged view from an underside looking upward of a box rail  58 . Second box wall top surface  34  is a surface of box rail  58 . Box rail  58  may be attached to a skin or wall  64  by using a box rail support  60  and a box rail support  62 . Welding or other fasteners could be used to attach box rail support  60  and a box rail support  62  to each of box rail and wall  64 . Hole  30  is depicted in  FIG. 3  as a through hole for guard post  24 .  FIG. 3  also depicts how a gap  66  is formed between box rail  58  and wall  64  by offsetting box rail  58  from wall  64  with box rail support  60  and box rail support  62 . By offsetting box rail  58  toward an interior of bell hole box  10  relative to wall  64 , as depicted in  FIGS. 1-3 , box rail  58 , all guard posts  24 , and all safety chains  28  installed around and into first box wall top surface  32  and second box wall top surface  34 , will not contact the soil or Earth into which bell hole box  10  is installed or placed. 
       FIG. 4  depicts first box wall  12  in an upright position with numerous holes  30  located in and along first box wall top surface  32 . Holes  30  are for insertion of, and for securing, guard posts  24  as depicted in a secured position in  FIG. 1 . Second box wall  14  may be a welded structure that generally has five major, separate straight portions  68 ,  70 ,  72 ,  74 ,  76 . Wall section  78  is an earth-contacting wall and is located outboard of box rail  80 . Box rail  80  is in-board of an entire length of first box wall  12 . Welding or another suitable fastening technique may be used to securely join wall support  82 , box rail  80 , and wall  78 .  FIG. 5  is an enlarged, underside view of box rail  80  noted in  FIG. 4 . Wall support  82  functions to provide connective and lateral support for wall  78  and box rail  80 . 
       FIG. 6  depicts second box wall  14  with spreader receiver assembly  20  and spreader receiver assembly  22  connected to an interior side of second box wall  14 .  FIG. 7  is an enlarged view of spreader receiver assembly  20 , which may be the same in construction, materials and dimensional characteristics as spreader receiver assembly  22  connected to second box wall  14 , but in a different location. Spreader receiver assembly  20  may be fabricated from multiple steel parts and welded together along longitudinal edges or sides. With reference also including  FIG. 14  and  FIG. 15 , spreader receiver assembly  20  may have an interior facing panel  84  that faces or is closest to an interior centerline of the bell hole box  10  interior, when bell hole box  10  is viewed from overhead. Interior facing panel  84  may be installed and fabricated using thru holes  90  cut into both adjacent side panels  86 ,  88  to which interior facing panel  84  is connected using tabs  96  cut or formed into interior facing panel  84 . A rear panel  94 , which may be a solid rear panel, may be used to complete a four-sided box-like structure that is spreader receiver assembly  20 ,  22 . More specifically, interior facing panel  84  may have protruding tabs  96  that may be rectangular tabs, cut along two elongated parallel edges or sides such that when installed into each side panel  86 ,  88 , protruding tabs  96  reside with thru holes  90 , which may be rectangular through holes, of each of side panel  86 ,  88 . Moreover, each recession  98  adjacent each protruding tab  96 ,  98  of interior facing plate  84  abuts against and contacts a flat surface of side panel  86 ,  88 . With protruding tabs  96  in a rectangular shape fitted into thru holes in a rectangular shape, a relatively stronger joint is established along a length of each interior facing panel  84 . Welding around or over the rectangular holes to connect interior facing panel  84  ad side panel  86 ,  88  may make the connection or joint even stronger. 
       FIG. 8  depicts a spreader receiver assembly  92  typical of what may be mounted, connected or welded to an interior wall of first box wall  12  opposite spreader receiver assembly  20 ,  22  mounted on second box wall  14 .  FIG. 1  also shows spreader receiver assembly  92  in position opposite spreader receiver assembly  20  and engaging first spreader  16 . 
       FIG. 9  depicts first spreader  16  and second spreader  18 , also known as a connective wall, of bell hole box  10 . Although two spreaders may normally be used, since their construction and function are or may be equal, discussion of only one will be made here. First spreader  16  may be entirely made of metal and may have a top plate  100  with a generally flat surface  102 . Under top plate  100  may be a hollow or generally hollow cavity, with top plate  100  acting as one of the confining walls to define the hollow cavity. The other confining walls may be bottom curved plate  104  that is joined by two relatively larger side plates, first spreader side plate  106  and second spreader side plate  108 , and side panel  109 . As depicted in  FIG. 9 , through holes  110  may be cut or stamped out of each of first spreader side plate  106  and second spreader side plate  108  to create a more lightweight structure while maintaining the necessary strength requirements of first spreader  16 .  FIG. 9  also depicts four through holes  112 , which are utilized to secure first spreader  16  and second spreader  18  to each of first box wall  12  and second box wall  14 , as depicted in  FIG. 1 . Continuing, to secure first spreader  16  and second spreader  18  to each of first box wall  12  and second box wall  14 , a clevis pin  114  ( FIG. 10 ) may be inserted through each of through hole  112 . Each clevis pin  114  may be secured or locked into position, to prevent removal of clevis pin  114  from all insertions within first spreader  16  and second spreader  18 , with use of a hitch pin  116  ( FIG. 11 ) inserted through a through hole at each end of clevis pin  114 .  FIG. 10  and  FIG. 11  depict hitch pin  116 , with  FIG. 10  depicting the installation of hitch pin  116  through a through hole  118  at each end of clevis pin  114 . Hitch pin  116  may utilize a hitch pin ring  120  to secure the end of hitch pin  116  that is passed through, through hole  118  of clevis pin  114 . A hitch pin chain  122  may attach hitch pin ring  120  to prevent hitch pin ring  120  from becoming lost or otherwise separating from hitch pin  116 . 
     With reference again including  FIG. 1 , to assemble bell hole box  10 , hoist rings  36 ,  38  of first spreader  16  may be lifted using a lifting strap or chain, and a suitable lifting device, such as a backhoe or similar device capable of lifting first spreader  16 .  FIG. 12  is an enlarged view of hoist rings  36 ,  38 , which have component parts of a pivotable lifting loop  124 , a threaded bolt  126  with threads  128 , and a hub  130  through which threaded bolt  126  passes and that abuts against flat surface  102  of top plate  100 . Lifting loop  124  pivots about hub  130  about pivot point  131 . After first spreader  16  is lifted, and each of first box wall  12  and second box wall  14  is situated in its upright arrangement, as depicted in  FIG. 1 , first spreader  16  can be lowered such that first insertion leg  132  and second insertion leg  134  may be inserted into spreader receiver assembly  20  and spreader receiver assembly  92 , respectively. A similar process is followed to lower second spreader  18  into its corresponding spreader receiver assemblies. Upon first spreader  16  and second spreader  18  correctly installed, two clevis pins  114  per spreader receiver assembly  20  may be installed with locking hitch pins  116 . Guard posts  24  with multiple safety chains  28  installed between each guard post  24  may also be installed. As depicted in  FIG. 1 , the entire assembled bell hole box  10  may be lifted using hoist rings  36 ,  38 ,  40 ,  42  and placed into the Earth. 
       FIG. 14  is a view of side panel  86 ,  88  that are used to manufacture a spreader receiver assembly  20 ,  22  ( FIG. 7 ) and spreader receiver assembly  92  ( FIG. 1 ). Side panels  86 ,  88  are also used to manufacture the counterpart spreader receiver assembly that cannot be seen in  FIG. 1 , but into which part of second spreader  18  may be inserted.  FIG. 14  also depicts through holes  90  that are defined in side panel  86 ,  88 , along a curved edge portion of side panel  86 ,  88  and into which tabs  96  ( FIG. 15 ) of interior facing panel  84  may be inserted to form three sides of a spreader receiver assembly  20 ,  22 ,  92 . Rear panel  94  completes the four sides of spreader receiver assembly  20 ,  22 ,  92  as depicted in  FIG. 7 .  FIG. 7 ,  FIG. 8 , and  FIG. 14  each depict through holes  26  in side panels  86 ,  88 . 
       FIG. 16  is a perspective view of another embodiment of a bell hole box. From  FIG. 16 , one can see that bell hole box  150  employs arcuate side wall  152  and arcuate side wall  154  instead of having flat or straight sides that are welded together, joined together, or otherwise angled as depicted in  FIG. 1 . Also, as depicted in  FIG. 16 , a ladder  160  may connect at one or multiple locations on either or both of arcuate side wall  152  or arcuate side wall  154 . Top frame rail  155  is situated on top of arcuate side wall  154  and arcuate side wall  152 . 
       FIG. 17  is an enlarged view of a bottom earth-contacting portion of arcuate side wall  152 . As an extension piece projecting from bottom surface  162  is a tapered surface  156  that becomes thinner as the distance away from bottom surface  162  becomes greater. At tip  158  of tapered surface  156  is a point of sufficient strength to not bend or break when bell hole box  150  is placed upon an earthen (e.g. dirt, sand, rocky soil) surface, such as in a hole. Bell hole box  150  may then be contacted or hydraulically pressed with a loading machine to ensure that bell hole box  150  will not shift or move under its own weight, such as due to a slightly uneven or wet surface of earth. 
       FIG. 18  is an enlarged view of a top rail  166  of an arcuate side wall  152  of bell hole box  150 . Installed in top rail  166  is a guard post  24 . Safety chains are not depicted in  FIG. 18 . 
       FIG. 19  is a perspective view from underneath bell hole box  150  with arcuate side wall  150  and arcuate side wall  154 . Also depicted installed in arcuate side wall  154  is ladder  160  in a position of non-use, and another ladder  160  in a position that is ready for use, which is also shown in the enlarged view of  FIG. 20 . Ladder  160  depicted in the position of non-use, in which the entirety of ladder  160  is situated against arcuate side wall  154 , may be secured with spring clips (not shown) or locking extension bracket  168  ( FIG. 20 ) that is retractable, and similar to, or the same as, a mechanism that may be found on a step ladder that extends at its bottom. At an opposite, top end of ladder  160 , simple pins may be passed through rails of ladder  160 . Alternatively, hinges may be used on each longitudinal, vertical rail of ladder  160 . 
       FIG. 20  is an enlarged view of a bottom of ladder  160  and depicts an extension device  164  that locks in an extended position, but that is also retractable to permit ladder  160  to be vertical or substantially vertical and mount completely against arcuate side wall  154 . 
       FIG. 21  is a top view of bell hole box  150  with arcuate side wall  152  and arcuate side wall  154  that also depicts a first spreader  170  and a second spreader  172 . Each spreader  170 ,  172  is connected to each arcuate side wall  152 ,  154 . A ladder  160  is depicted in two possible positions, although positioning a ladder is possible anywhere along arcuate wall  152  and arcuate wall  154 . Ladder  160  extends out at its bottom connection point to either arcuate side wall  152 ,  154  and pivots at its top connection point. 
       FIG. 22  is a perspective view of a first bell hole box  150  stacked on top of a second bell hole box  174 , which have the same wall height. An example wall height is 96 inches (243.84 centimeters), although any wall height is conceivable. Two full size ladders  160  are depicted in two locations. A first location depicts ladders in a stowed or folded position such that ladder  160  is stored flat or substantially flat against arcuate side wall  152 . A second location depicts ladders in an extended or in-use position such that ladder  160  is not stored flat or substantially flat against arcuate side wall  152 , but rather is extended away from side wall  154  at a bottom end of ladder  160 . To facilitate ingress and egress from bell hole boxes  150 ,  174  only bottom ladder next to an Earthen surface upon which bell hole box  174  resides, will have its ladder  160  extend away from arcuate side wall  154 , while ladder  160  in bell hole box  150  stacked directly above bell hole box  174  may be located directly against arcuate side wall  154  or extended slightly to whatever degree facilitates safe ingress and egress. As shown in  FIG. 20 , extension device  164  of ladder  160  is adjustable. Any ladder  160  of any bell hole box  10 ,  150 ,  174  may have a bottom rung that is 6 to 12 inches above the bottom of the wall to which the ladder  160  is mounted. 
       FIG. 23  is an enlarged view of a junction, mating or seating location where a first bell hole box  150  stacks on top of a second bell hole box  174 . Junction more specifically entails a bottom flat surface  162  of bell hole box  150  seats against a top flat surface  176  of bell hole box  174  (a bell hole box positioned under or below bell hole box  150 ). When bottom surface  162  seats with top surface  176 , tapered surface  156  seats or contacts surface  178  of bell hole box  174 . Holes  30  in any bell hole box  10 ,  150 ,  174  may be used as a location to mount a winch or other accessories. Any tapered surface on a bottom of bell hole box  10 ,  150 ,  174  may be used to driven into a bottom of a trench. 
       FIG. 24  is an enlarged view of a junction of bell hole box  150  stacked on top of bell hole box  174 . When bell hole box  150  is lowered in accordance with arrow  184  ( FIG. 23 ), the arrangement of  FIG. 24  results with bottom surface  162  of bell hole box  150  contacting top flat surface  176  of bell hole box  174  with tapered surface  156  contacting tapered surface  176 . As depicted, tip  158  of protruding wedge portion  184  may not reach an edge  180  of wall  182  of bell hole box  174 . As depicted, when mated or joined, protruding wedge portion  184  of bell hole box  184  will fit inside vertical side support frame  190 . 
       FIG. 25  is an enlarged view of a junction of first bell hole box  150  stacked on top of second bell hole box  174  depicting top plate  186  and an end of spreader  188  contacting a bottom of bell hole box  150 , that is, the upper bell hole box in the arrangement of  FIG. 25 . 
       FIG. 26  is an enlarged view of an ingress and egress location of bell hole box  150 . Guard rail posts  192  will fit within holes in top rail  194  at the location of guard rail posts  192 . Extensions to ladder sides may be added as part of guard rail posts  192  and reside above a top end  196  of ladder  160  (not shown). Ladder  160  may or may not pivot about point  198  at top of ladder  160 . 
       FIG. 27  is a perspective view of another embodiment of a bell hole box  200 . As an example, bell hole box  200  may be an assembly of a top bell hole box  202  and a bottom bell hole box  204  such that top bell hole box  202  has a wall height that is less than a wall height of bottom bell hole box  204 . A mating, junction or contact plane  206  is where top bell hole box  202  and bottom bell hole box  204  contact and form bell hole box  200 . A first separator  208  and a second separator  210  may be used to maintain a prescribed distance between, and secure a first wall  212  of bottom bell hole box  204 , a second wall of bottom bell hole box  204 , a first wall  216  of top bell hole box  202  and a second wall of top bell hole box  202 . 
       FIG. 28  is an enlarged view of an upper location of top bell hole box  202  when top bell hole box  202  and is stacked on top of bottom bell hole box  204 . Next to first spreader  208  is a winch mounting  220 , which may be used for mounting part of a winch or connecting an end of a winch cable to use to lift top bell hole box  202  from bottom bell hole box  204 , or to lift the entire bell hole box  200 . 
       FIG. 29  is an enlarged view of an upper location of top bell hole box  202  when top bell hole box  202  is stacked on top of bottom bell hole box  204 . Next to second spreader  210  is a winch mounting  222 , which may be used for mounting part of a winch or connecting an end of a winch cable to use to lift top bell hole box  202  from bottom bell hole box  204 , or to lift the entire bell hole box  200 . Winch mount  222  depicted as part of  FIG. 29 , may be an alternative to winch mount  220  of  FIG. 28 . 
       FIG. 30  is an enlarged view of an upper location of top bell hole box  202  when top bell hole box  202  is stacked on top of bottom bell hole box  204 . Depicted above ladder  160 , which may be mounted and operated similarly to other ladders  160  installed in bottom bell hole boxes, such as described in conjunction with  FIG. 16 , for example, is a ladder  224  which may be shorter than ladder  160 . Also resident along a top surface  232  of top bell hole box  202  is stake or post pocket  226  within which may reside a stake or post  230  ( FIG. 27 ), with safety chains connecting the posts  230 . Instead of stake or post pocket  226  residing on an outside surface of top bell hole box  202 , stake or post pocket  228  may reside within top surface  232  of top bell hole box  202 . 
       FIG. 31  is an enlarged view of top bell hole box  202  when top bell hole box  202  is stacked on top of bottom bell hole box  204 . A location of shortened ladder  224  above ladder  160 , with safety chains  28  installed between railing posts or guard posts  230 .  FIG. 32  is a top view of top bell hole box  202  stacked on top of bottom bell hole box  204  depicting example locations for multiple ladders  160 ,  224  around an interior of bell hole box  200 . 
     In any of the embodiments described above, a ladder  160 ,  224  may be attached to an interior surface of a box wall or arcuate wall such that a top of the ladder  160 ,  224  may pivot to permit a bottom of the ladder  160 ,  224  to move away from the wall to permit a worker to enter and exit the specific bell hole box to which the ladder  160 ,  224  is attached. An extension device may be attached at the bottom of the ladder  160 ,  224  to permit the ladder  160 ,  224  to be movable to a swung-out position away from a wall to which the ladder  160 ,  224  is attached. A locking mechanism built into the extension device  164  may be employed to lock the ladder  160 ,  224  in an extended position away from the wall to which it is attached. The wall may be straight (e.g. flat) or arcuate (e.g. curved). The ladder may attach to a wall panel or a vertical or horizontal structural member that supports the wall panel. Welding or loose fasteners may be employed to attach the ladder. The walls of a bottom bell hole box and a top bell hole box may be made of linear sections to form a working space within the bottom bell hole box and the top bell hole box that is eight sided, including straight sections of both spreader bars. 
       FIG. 33  is an enlarged perspective view of ladder  160  residing in its near-installed position next to an interior surface of a wall of a bell hole box. When installed, ladder  160  in one embodiment will be securely fastened to vertical post  234  using hole  236  in post  234 , and hole  238  in a longitudinal rail of ladder  240 , with a fastener such as a bolt passing through both holes  236 ,  238  to secure ladder adjacent or against an interior surface of a wall of bell hole box. A similar fastening arrangement may exist at a top end  196  of ladder. That is, a fastener may pass through both, a hole  240  of post  234  and a hole  242  at a top end  196  of ladder rail of ladder  160 . Fasteners are not depicted in  FIG. 33 . 
       FIG. 34  is an enlarged perspective view of ladder  160  in its near-installed position next to an interior surface of a wall of a bell hole box. However, in this embodiment, as also depicted in  FIG. 20 , ladder  160  may exhibit an extension device  164  that may be made up of a first bar  244  and a second bar  246  that are connected with a pin  250 . A hole  248  in second bar  246  may be made to align with hole  236  in post  234  to securely mount the ladder to the interior of the bell hole box. Similarly, a bar  252  may be a connector between post  234  and ladder  160 , by connecting to each of post  234  and ladder  160  by using a traditional fastener such as a bolt (not shown). Because at least a single bar  252  is used at the top of ladder  160  and bar  252  is able to pivot at each of its ends, one end of bar  252  relative to ladder  160  and the other end of bar  252  relative to post  234 , bottom ends or feet of ladder  160  are able to contact the earth or floor of whatever the bell hole box is resting upon when in its in-use position, and bottom ends or feet of ladder  160  are able to store against or adjacent an interior wall of bell hole box when ladder  160  is lifted or moved to its stowed position. Ladder  160  may be stored at one or more positions about interior of a bell hole box, as depicted in  FIG. 32  and  FIG. 21 . 
       FIGS. 35-38  each depict a perspective view of a ladder assembly  260  that is mountable to the interior support structure of the bell hole box. Ladder assembly  260  is a combination of parts that permit safe entry into and exit from bell hole box  150 , for example, as depicted in  FIG. 16 . Ladder assembly  260  can be considered a type of automated version of a ladder compared to a ladder that is merely bolted to an interior surface of bell hole box as depicted in  FIG. 16 .  FIGS. 35-38  depict ladder assembly  260  having a first ladder support  262 , a second ladder support  264 , a first ladder rung support  266 , and a second ladder rung support  268 . First ladder rung support  266  and second ladder rung support  268  are parallel members and are each directly connected to numerous ladder rungs  270  along the lengths of first ladder rung support  266  and second ladder rung support  268 . Ladder rungs  270  are located between first ladder rung support  266  and second ladder rung support  268 . First ladder rung support  266  and second ladder rung support  268  are located between first ladder support  262  and second ladder support  264 . First ladder support  262 , second ladder support  264 , first ladder rung support  266 , and second ladder rung support  268  all may be parallel to each other. Attached to first ladder support  262  is a first handle bar  272 , and attached to second ladder support  264  is a second handle bar  274 . Each of first handle bar  272  and second handle bar  274  protrude above ladder assembly  260 , and also protrude above a top rail of any bell hole box to which ladder assembly is fastened or installed, so that a human hand may grasp either. First ladder rung support  266  and second ladder rung support  268 , along with connecting rungs  270  are located inside, in between, or inboard of first ladder support  262  and second ladder support  264 . 
       FIGS. 35-38  also each depict a rotatable crank guide  276 , which is attached to a threaded drive rod  278 , which is journaled or held in place by an upper drive rod mount  280 , and a lower drive rod mount  282 . Drive rod  278  is threaded and passes through a curved drive link  284 . Because upper drive rod mount  280  and lower drive rod mount  282  are both securely fastened to first ladder support  262 , curved drive link moves upward and downward because the hole in curved drive link  284  is threaded, and its threads engage the mating threads of drive rod  278 . Thus, when ladder assembly  260  is securely fastened to an internal wall of trench box  150  of  FIG. 19 , and crank guide  276  is turned clockwise, for example, curved drive link  284  moves downward away from upper drive rod mount  280  which causes bottom of ladder to pivot outwardly and away from an interior wall of bell hole box  150  and into the position depicted in  FIG. 19  and  FIG. 20 . 
     More specifically, and with continued reference to  FIGS. 35-38  when crank guide  276  is turned clockwise and curved drive link  284  moves downward away from upper drive rod mount  280 , curved drive link  284  also drives curved ladder link  286  downward and outward away from first ladder support  262  and second ladder support  264 , while bottom ladder short link  288  and bottom ladder long link  290  ( FIG. 37 ) begin to move generally away from first ladder support  262  and second ladder support  264 , as depicted in  FIG. 19  and  FIG. 20 . Similarly, first upper ladder link  294  and second upper ladder link  296  are also driven in a similar direction away from an interior bell hole box wall as bottom rung moves away from the interior wall. Because curved ladder link  286  ( FIG. 37 ) is attached to a longitudinal ladder link  298  ( FIG. 35 ), which is directly or indirectly attached to first upper ladder link  294  and bottom ladder short link  288 , the rungs  270  attached to first ladder rung support  266  and second ladder rung support  268  are extended and settled in a non-vertical fashion as depicted in  FIGS. 19, 20 and 22 , which makes them climbable by a person. 
     Any part depicted in any embodiment of  FIGS. 1-38 , whether or not enumerated or discussed in this written specification, may be mounted, attached to, or incorporated into another embodiment when such part is not depicted in that other embodiment. For example, ladder  160  depicted in  FIGS. 16, 19, 22, 27 and 32  may be mounted, adapted into or otherwise installed into bell hole box  10  depicted in  FIG. 1 . Moreover, each and every claim below is hereby incorporated into this detailed description or specification as additional embodiments of the present invention. Although the systems and processes described herein have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention as defined by the following claims. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described herein. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims while the description, abstract and drawings are not to be used to limit the scope of the invention. The invention is specifically intended to be as broad as the claims below and their equivalents.