Patent Publication Number: US-2022220689-A1

Title: Trench box and method of assembly

Description:
TECHNICAL FIELD 
     This relates to a trench box and a method of assembling a trench box. 
     BACKGROUND 
     Trench boxes are used for protection during excavation. Trench boxes may be used when installing pipelines, underground cabling, or performing other operations that require below-ground access. 
     A typical trench box will include side panels that are separated and held in place by struts, which may be length-adjustable to meet the needs of the particular trench. It is necessary to construct the panels and struts from materials that are able withstand the loads that will be applied. 
     Trench boxes are generally assembled by laying a side panel flat on the ground, attaching the struts so they extend up from the side panel, and then lowering the other side panel onto the struts. Given the weight of the various components, lifting equipment is normally required, and personnel are required to ensure the various pieces are properly aligned as they are manipulated by the lifting equipment. 
     SUMMARY 
     According to an aspect, there is provided a trench box, comprising first and second side panels connected in parallel spaced relation by one or more lateral supports. Each lateral support comprises connection points at a first end and a second end of each lateral support that connect the first and second side panels to the one or more lateral supports, the connection points maintaining the first and second side panels in parallel spaced relation and the one or more lateral supports in parallel spaced relation between the first and second side panels. Each connection point comprises a pivot connection that permits pivotal movement of the side panels relative to the one or more lateral supports about a pivot axis, and a releasable connection spaced from the pivot connection in a direction perpendicular to the pivot axis, the releasable connection being selectively releasable to permit the respective first or second side panel to pivot about the pivot axis such that the panels are not parallel. 
     According to another aspect, the trench box may further comprise side supports mounted between the side panels and the one or more lateral supports, the side supports extending along the side panels in a direction perpendicular to the pivot axis. The connection points may connect the lateral support to the side supports. The side panels may be removably mounted to the side supports. When the releasable connections are released, the side supports may pivot sufficiently about the pivot axis to permit the one or more stands to engage the ground surface, or the side supports may be fixedly mounted to the lateral supports such that the side panels pivot relative to the lateral supports and the side supports. 
     According to another aspect, there may be one or more stands that support the lateral support when on a ground surface. The pivot connection is spaced from the releasable connection and may be above the releasable connection. 
     According to another aspect, the releasable connections may be spring-loaded connections. 
     According to another aspect, the lateral supports may be length-adjustable to adjust a spacing between the first and second side panels. 
     According to another aspect, the height of the first and second side panels may be greater than a height of the lateral supports, such that, when the lateral support is supported by the one or more stands on the ground surface, the first and second side panels are angled downward and outward relative to the lateral supports. 
     According to another aspect, each lateral support may comprise lifting lugs that permit the lateral supports to be suspended by a lifting device such that the side panels are free to pivot about the pivot connections when the lateral supports are lifted sufficiently. 
     According to another aspect, the trench box may further comprise one or more third side panel that attaches to one or more of the first and second side panels. The one or more third side panel may attach to the first side panels using a corner engagement member, the corner engagement member having an engagement profile that secures the one or more third side panel perpendicularly to the first side panel. The one or more third side panels may attach to a top edge of the first or second side panel using an engagement member, the engagement member having an engagement profile that secures the one or more third side panels in a common plane with at least one of the first and second side panels. 
     According to another aspect, a perimeter of the first and second side panels may comprise a universal engagement profile that is engaged by a universal engagement member. 
     According to another aspect, each side panel may comprise at least one snubber for controlling the pivotal movement of each side panel relative to the lateral supports. 
     According to an aspect, there is provided a method of assembling a trench box, comprising the steps of: positioning one or more lateral supports in parallel spaced relation and in a vertical orientation. Each lateral support comprises connection points at a first end and a second end of each lateral support, each connection point comprising a pivot connection, and a releasable connection spaced below the pivot connection when the lateral support is in the vertical orientation; and one or more stands for supporting the support structure in the vertical orientation. The method further comprises the steps of pivotally attaching a first side panels to the pivot connections at the first end of each lateral support, and a second side panel to the pivot connections at the second end of each lateral support, the side panels being angled down and away relative to the lateral supports; lifting the lateral supports such that the first and second side panels pivot toward the lateral supports; and engaging the releasable connection such that the first and second side panels are secured in parallel spaced relation with the one or more lateral supports in parallel spaced relation between the first and second side panels. 
     According to an aspect, there is provided a method of disassembling a trench box, the method comprising the steps of: providing a trench box, comprising one or more side panels connected in parallel spaced relation by first and second lateral supports. Each lateral support comprising connection points at a first end and a second end of each lateral support that attach the first and second side panels to the one or more lateral supports, the connection points maintaining the first and second side panels in parallel spaced relation and the one or more lateral supports in parallel spaced relation between the first and second side panels; each connection point comprising a pivot connection that permits pivotal movement of the side panels relative to the lateral supports about a pivot axis, and a releasable connection spaced from the pivot connection in a direction perpendicular to the pivot axis, the releasable connection being selectively releasable to permit the respective first or second side panel to pivot about the pivot axis such that the panels are not parallel; at least one snubber for controlling the pivotal movement of each side panel relative to the lateral supports; and one or more stands that support the lateral support when on a ground surface with the pivot connection spaced from the releasable connection. The method further comprises the steps of positioning the trench box on a ground surface such that the trench box is supported on a bottom edge of the first and second side panels with the lateral supports parallel to the ground surface; releasing the releasable connection of the first side panel, and applying a force to the first side panel that causes it to pivot about the pivot connection until it is angled downward and away from the lateral support, the pivotal movement of the first side panel being controlled by one or more of the snubbers; releasing the releasable connection of the second side panel, and applying a force to the second side panel that causes it to pivot about the pivot connection until it is angled downward and away from the lateral support and such that the one or more stands engages the ground surface, the pivotal movement of the second side panel being controlled by one or more of the snubbers; and removing the first and second side panels from the lateral support. 
     According to another aspect, the releasable connection of the first and second side panels may be released together such that the first and second side panels pivot at the same time. 
     According to an aspect, there is provided a method of disassembling a trench box, the method comprising the steps of: providing a trench box, comprising first and second side panels connected in parallel spaced relation by one or more lateral supports. Each lateral support comprises connection points at a first end and a second end of each lateral support that attach the first and second side panels to the one or more lateral supports, the connection points maintaining the first and second side panels in parallel spaced relation and the one or more lateral supports in parallel spaced relation between the first and second side panels; each connection point comprising a pivot connection that permits pivotal movement of the side panels relative to the lateral supports about a pivot axis, and a releasable connection spaced from the pivot connection in a direction perpendicular to the pivot axis, the releasable connection being selectively releasable to permit the respective first or second side panel to pivot about the pivot axis such that the panels are not parallel. The method may further comprise the steps of: positioning the trench box such that a top edge of the first and second side panels engages a ground surface; releasing the releasable connections of the first and second side panels; and pivotally lowering the first and second side panels until an outer face of the first side panel and an outer face of the second side panel engage the ground surface. 
     According to an aspect, there is provided a method of disassembling a trench box, the method comprising the steps of: 
     providing a trench box that comprises first and second side panels connected in parallel spaced relation by one or more lateral supports, each lateral support comprising connection points at a first end and a second end of each lateral support that attach the first and second side panels to the one or more lateral supports, the connection points maintaining the first and second side panels in parallel spaced relation and the one or more lateral supports in parallel spaced relation between the first and second side panels; and each connection point comprising a pivot connection that permits pivotal movement of the side panels relative to the one or more lateral supports about a pivot axis, and a releasable connection spaced from the pivot connection in a direction perpendicular to the pivot axis, the releasable connection being selectively releasable to permit the respective first or second side panel to pivot about the pivot axis such that the panels are not parallel; 
     positioning the trench box such that an outer surface of the first side panels engages a ground surface;
         lifting the second side panel such that the second side panel moves pivotally relative to the first side panel, and lowering the second side panel until an outer surface of the second side panel engages the ground surface spaced from the first side panel by the one or more lateral supports, the releasable connections being released to permit relative movement of the first and second side panels; and   removing the one or more lateral supports from the first and second side panels.       

     According to an aspect, there is provided a trench box, comprising first and second side panels, each side panel having an inner face and an outer face, the inner face having an upper attachment point having a first part of an upper attachment and a lower attachment having a first part of a lower attachment, one or more support structures, each support structure comprising first and second sides supports separated by a lateral support, wherein in use, the lateral support maintains the first side support in a fixed position and orientation relative to the second side support, each of the first and second side supports carrying a second part of the upper attachment and a second part of a lower attachment, the second part of the upper attachment pivotally engaging the first part of the upper attachment and the second part of the lower attachment fixedly engaging the first part of the lower attachment, each of the upper attachment and the lower attachment being selectively engaged and disengaged, and a stand for supporting the support structure in a vertical orientation with the second part of the upper attachment above the second part of the lower attachment. 
     According to another aspect, at least one of the upper attachment and the lower attachment may be pin connected. 
     According to another aspect, at least one of the upper attachment and the lower attachment may be spring-loaded connectors. 
     According to another aspect, the lateral support of the support structures may be length-adjustable to adjust a spacing between the first and second side supports. 
     According to another aspect, the stand may be removably attached to the second part of the lower attachment, the stand being removed to permit the first parts of the lower attachments to connect to the respective second part of the lower attachments. 
     According to another aspect, one of the first part and the second part of the lower attachment may comprise an engagement face and the other of the second part and the first part of the lower attachment may comprise a receiver having a pin that slides along the engagement face to retain the engagement face that is received within the receiver. 
     According to another aspect, a first distance between the first part of the upper attachment and a lower edge of the respective panel may be greater than a second distance between the second part of the upper attachment and the stand, such that, when the first and second parts of the upper attachment are connected and the stand supports the support structure on a ground surface, the first and second panels are angled downward and outward relative to the support structure. 
     According to another aspect, each support structure may comprise lifting lugs that permit the support structures to be suspended by a lifting device such that the panels are free to pivot about the upper attachments when the support structure is lifted sufficiently. 
     According to another aspect, the trench box may further comprise one or more third side panels that attach to and extend between the first and second side panels. 
     According to another aspect, the one or more third side panels may attach to the first side panel using a corner engagement member, the corner engagement member having an engagement profile that secures the one or more third side panel perpendicularly to the first panel. 
     According to another aspect, the trench box may further comprise one or more third side panels, each third side panel being attached to and extending above a top edge of one of the first and second side panels. 
     According to another aspect, the one or more third side panels may attach to the top edge of the respective side panels using an engagement member having an engagement profile that secures the one or more third side panels in a common plane with at least one of the first and second side panels. 
     According to another aspect, a perimeter of the side panels may comprise a universal engagement profile that is engaged by a universal engagement member. 
     According to an aspect, there is provided a method of assembling a trench box, comprising the steps of positioning one or more support structures in spaced relation and in a vertical orientations, each support structure comprising first and second sides supports separated by a lateral support, wherein in use, the lateral support maintains the first side support in a fixed position and orientation relative to the second side support, one or more stands for supporting the support structure in the vertical orientation, attaching first and second side panels to the one or more support structures using a pivotal attachment, the pivotal attachment being positioned toward a top of each of the first and second side panels and the one or more support structures, the first and second side panels being angled down and away from the one or more support structures, lifting the support structures such that the first and second side panels pivot toward the support structures, removing the one or more stands, and attaching the first and second side panels to the support structures at a point below the pivotal attachments. 
     According to another aspect, attaching the first and second side panels to the one or more support structures may comprise using at least one pin connection. 
     According to another aspect, attaching the first and second side panels to the one or more support structures may comprise using at least one spring-loaded connector. 
     According to another aspect, attaching the first and second side panels to the support structure at a point below the pivotal attachments may comprise inserting a pin connector into a pin receiver. 
     According to another aspect, the lateral supports of the support structures may be length-adjustable, and the method may further comprising the step of adjusting a spacing between the first and second side supports by adjusting the length of the lateral supports. 
     According to another aspect, the stand may be removably attached to the second part of the lower attachment, and the method may further comprise removing the stand and connecting the first parts of the lower attachments to the respective second part of the lower attachments. 
     According to another aspect, attaching the first and second side panels to the support structures at a point below the pivotal attachments may comprise sliding a pin being carried by a receiver on one of the first part and the second part of the lower attachment along an engagement face, the other of the first part and the second part of the lower attachment comprising the engagement face, to retain the engagement face within the receiver. 
     According to another aspect, a first distance between the first part of the upper attachment and a lower edge of the respective panel may be greater than a second distance between the second part of the upper attachment and the stand, such that, when the first and second parts of the upper attachment are connected and the stand supports the support structure on a ground surface, the first and second panels are angled downward and outward relative to the support structure. 
     According to another aspect, the method may further comprise the step of suspending the support structures with a lifting device connected to lifting lugs on each support structure such that the panels are free to pivot about the upper attachments. 
     According to another aspect, the method may further comprise the step of attaching one or more one third side panels to the first and second side panels such that the one or more third side panels extend between the first and second side panels. 
     According to another aspect, the one or more third side panels may attach to the first side panel using a corner engagement member, the corner engagement member having an engagement face that secures the one or more third side panels perpendicularly to the first side panel. 
     According to another aspect, the method may further comprise the step of attaching one or more third side panels to a top edge of one of the first and second side panels such that the one or more third side panels extend above a top edge of at least one of the first and second side panels. 
     According to another aspect, the one or more third side panels may attach to the top edge of the respective side panels using an engagement member. 
     According to another aspect, a perimeter of the first and second side panels may comprise an engagement profile that is engaged by an engagement member having an engagement profile that secures the one or more third side panels in a common plane with at least one of the first and second side panels. 
     According to an aspect, there is provided a trench box, comprising first and second side panels, each side panel having an inner face, an outer face and an outer peripheral edge, one or more support structures attached between the inner faces of the first and second side panels to maintain the first side panel in a fixed position and orientation relative to the second side panel, a universal connector on the outer peripheral edge of each of the first and second side panels, the universal connector comprising a plurality of connection points that are evenly spaced along the outer peripheral edge, and a removable connector that selectively connects to the universal connector. 
     According to an aspect, there is provided a trench box assembled for use in an excavation, the trench box comprising a plurality of panels comprising at least a first panel, a second panel, and a third panel. Each panel comprises a connection profile comprising a plurality of straight edge segments along the peripheral edges of the panel, each straight edge segment having a plurality of evenly spaced connection points, wherein the spacing of connection points on each straight edge segment is equal. The first and second panels are secured in parallel, spaced relation. A plurality of connectors connect between connection profiles. At least one connector connects the third panel and the first panel to secure the third panel relative to the first and second panels. 
     According to another aspect, the first and second panels may be secured in parallel, spaced relation by one or more lateral supports that have a first end connected to the first panel and a second end connected to the second panel. 
     According to an aspect, the plurality of connectors further connect the third panel and the second panel. The plurality of connectors may further connect a fourth panel to the first and second panels, wherein the first and second panels are secured in parallel, spaced relation by the third and fourth panels. The third and fourth panels may be in parallel spaced relation. 
     According to another aspect, the third panel may be connected parallel to and in alignment with the first panel, or at an angle to the first panel. 
     According to another aspect, each panel may be rectangular and have a length and a width, the connection profile extending along each of the length and the width of each panel, wherein at least the length and the width of the third panel are non-equal, such that each of the length and the width of the third panel can be connected to each of the length and the width of the first panel. 
     According to an aspect, there is provided a method of installing a trench box or use in an excavation having sidewalls, the method comprising the step of: providing a plurality of panels comprising at least a first panel, a second panel, and a third panel, each panel comprising a connection profile having a plurality of straight edge segments along the peripheral edges of the panel, each straight edge segment having a plurality of evenly spaced connection points, wherein the spacing of connection points on each straight edge segment is equal; providing a plurality of connectors that connect between connection profiles; assembling the trench box by: securing the first and second panels together in parallel, spaced relation; and using one or more connectors to connect the third panel and the first panel to secure the third panel relative to the first and second panels. 
     According to an aspect, the first and second panels may be secured in parallel, spaced relation by one or more lateral supports that have a first end connected to the first panel and a second end connected to the second panel. 
     According to another aspect, one or more connectors may be used to connect the third panel and the second panel. The method may further comprise the step of using the connectors to connect a fourth panel to the first and second panels, wherein the first and second panels are secured in parallel, spaced relation by the third and fourth panels. The third and fourth panels may be in parallel spaced relation. 
     According to another aspect, the third panel may be connected parallel to and in alignment with the first panel, or at an angle to the first panel. 
     According to another aspect, each panel may be rectangular and have a length and a width, the connection profile extending along each of the length and the width of each panel, wherein at least the length and the width of the third panel are non-equal, and further comprising the steps of: identifying a plurality of arrangements in which the length and the width of the third panel can be connected to each of the length and the width of the first panel, and selecting one of the plurality of arrangements. 
     According to another aspect, the method may further comprise the step of installing the trench box in the excavation to support at least a portion of the sidewalls of the excavation. 
     In other aspects, the features described above may be combined together in any reasonable combination as will be recognized by those skilled in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein: 
         FIG. 1  is a perspective view of an embodiment of a trench box. 
         FIG. 2  is a perspective view of a support structure. 
         FIG. 3  is a perspective view of two support structures spaced apart from each other. 
         FIG. 4  is a perspective view of the trench box of  FIG. 1  with panels attached to upper attachments. 
         FIG. 5  is a side elevation view of the trench box of  FIG. 1  with panels attached to upper attachments. 
         FIG. 6  is a side elevation view of the trench box of  FIG. 1  being lifted away from a stand. 
         FIG. 7  is a side elevation view of the trench box of  FIG. 1  with panels attached to the upper and lower attachments. 
         FIG. 7A  is a side elevation view of the trench box of  FIG. 1  being lowered into a trench. 
         FIG. 8  is a perspective view of the trench box of  FIG. 1  with panels attached to the upper and lower attachments showing a detailed view of a lower attachment. 
         FIG. 9  is a perspective view of a trench box with an alternate support structure. 
         FIG. 10  is a side elevation view of the trench box of  FIG. 9  being rotated for disassembly. 
         FIG. 11  is a side elevation view of the trench box of  FIG. 9  on its side. 
         FIG. 12  is a side elevation view of the trench box of  FIG. 9  being rotated further for disassembly. 
         FIG. 13  is a side elevation view of the trench box of  FIG. 9  that has been rotated upside down for disassembly. 
         FIG. 14  is a perspective view of the trench box of  FIG. 9  showing a detailed view of a lower attachment. 
         FIG. 15  is a side elevation view of the trench box of  FIG. 9  showing the process of a side panel rotating about a lower attachment to lay flat. 
         FIG. 16  is a side elevation view of the trench box of  FIG. 9  showing the second side panel rotating about a lower attachment such that both panels lay flat. 
         FIG. 17  is a side elevation view of the trench box of  FIG. 9  showing the support structures being lifted away from the side panels. 
         FIG. 18  is a perspective view of a side panel. 
         FIG. 19  is a perspective view of a side panel showing the interior structure. 
         FIG. 20  is a perspective view of a portion of a side panel showing an upper attachment with a closed safety latch. 
         FIG. 21  is a perspective view of a portion of a side panel showing an upper attachment with an open safety latch. 
         FIG. 22  is a side elevation view in section of a trench box with an alternate attachment system. 
         FIG. 23 a    is a side elevation view of the trench box of  FIG. 22  showing a detailed view of an upper attachment. 
         FIG. 23 b    is a side elevation view of the trench box of  FIG. 22  showing a detailed view of a lower attachment. 
         FIG. 24  is a perspective view of two side panels assembled using a corner bracket. 
         FIG. 25  is a perspective view of a corner bracket. 
         FIG. 26  is a perspective view of two side panels assembled using an inline bracket. 
         FIG. 27  is a perspective view of an inline bracket. 
         FIG. 28  is a perspective view of side panels assembled using both corner and inline brackets. 
         FIG. 29  is a perspective view of a trench box assembled using both corner and inline brackets. 
         FIG. 30  is a perspective view of a side panel having a knife edge component. 
         FIG. 31  is a side elevation view of the trench box of  FIG. 22  with a lifting sling attached. 
         FIG. 32  is a side elevation view of the trench box of  FIG. 22  being rotated for disassembly. 
         FIG. 33  is a side elevation view of the trench box of  FIG. 22  on its side. 
         FIG. 34  is a side elevation view of the trench box of  FIG. 22  showing the process of a side panel rotating about a lower attachment to lay flat. 
         FIG. 35  is a side elevation view of the trench box of  FIG. 22  showing the second side panel rotating about a lower attachment such that both panels lay flat. 
         FIG. 36  is a side elevation view of the trench box of  FIG. 22  showing the support structures being lifted away from the side panels. 
         FIG. 37  is a perspective view of lateral supports for a larger format trench box. 
         FIG. 38  is a perspective view of side panels being installed on the lateral supports of  FIG. 37 . 
         FIG. 39  is a perspective view of side panels installed on the lateral supports of  FIG. 37 . 
         FIG. 40  is a perspective view of one side panel in an operational position relative to the lateral supports. 
         FIG. 41  is a perspective view of a larger format trench box in an operational position. 
         FIGS. 42 and 43  are detailed perspective views of a releasable connection. 
         FIGS. 44 and 45  are detailed perspective views of a snubbing device. 
         FIG. 46  is a side elevation view in section of a snubbing device. 
         FIG. 47  is a detailed perspective view of a side support with a latch in a latched position. 
         FIG. 48  is a detailed side elevation view of a side support with a latch in a latched position. 
         FIG. 49  is a detailed side elevation view of a side support with a latch in an unlatched position. 
         FIG. 50  is a perspective view of four side panels assembled into a box using corner brackets. 
         FIG. 51  is a perspective view of eight side panels assembled into a vertically extended box using corner brackets. 
         FIG. 52  is a perspective view of a corner connector being attached to one side of a panel. 
         FIG. 53  is a perspective view of six side panels of equal size assembled into a box by varying the orientation and using corner brackets. 
         FIG. 54  is a perspective view of a trench box vertically extended using edge brackets. 
         FIG. 55  is a side elevation view of a locking pin on a connecting bracket showing detail of a pin keeper. 
         FIG. 56  is a perspective view of a locking pin being installed on a connecting bracket showing detail of a locking slot. 
         FIG. 57  is a side elevation view of a locking pin being installed on a connecting bracket showing the pin in an unlocked position. 
         FIG. 58  is a side elevation view of a locking pin being installed on a connecting bracket showing the pin rotated to a locked position. 
         FIG. 59  is a side elevation view showing details of a diamond shaped pin receiver for locking pins. 
         FIG. 60  is a perspective view of a side panel having attached extension feet. 
         FIG. 61  is a perspective view of a knife edge component being installed on a side panel. 
         FIG. 62  is a perspective view of two side panels being connected inline using edge brackets. 
         FIG. 63  is a perspective view of two side panels connected together inline using edge brackets. 
         FIG. 64  is a detailed top plan view of an edge bracket being connected to a connection profile on a side panel. 
         FIG. 65  is a detailed side elevation view of an edge bracket being connected to a connection profile on a side panel. 
     
    
    
     DETAILED DESCRIPTION 
     There will be given below a general description of a trench box, after which two examples of trench boxes will be given, namely, a smaller format trench box, described with respect to  FIG. 1 through 36 , and a larger format trench box, described with respect to  FIG. 37 through 46 . Additional details regarding a universal connection system for both the smaller format and larger format trench box will be described with respect to  FIGS. 24-30  and  FIG. 50-65 . The terms “smaller format” and “larger format” are intended to be relative to each other, and may be designed to the particular size required by the end user. It will also be understood that, while the overall designs of the different formats share many design concepts, there are some differences that arise based on the particular considerations related to the size and weight of the respective trench box. It will be understood that these design considerations are transferrable between designs, and may be incorporated in either one or the other, or another example of a trench box may be designed. The end design will depend, of course, on the dimensions and specifications required by the end user, the available materials and resources, the equipment available for installing and/or removing the trench box, etc. As such, unless it is clear that particular features are mutually exclusive, the options described with respect to one design may be incorporated into the other design. 
     Referring to  FIG. 1 , a smaller format trench box  10  is shown, while in  FIG. 41 , a larger format trench box  200  is shown. Elements that perform a similar function are identified by similar reference numbers. Trench boxes  10  and  200  have a first side panel  12  with an inner face  14  and an outer face  16 , and a second side panel  18  with an inner face  20  and an outer face  22 . Trench boxes  10  and  200  are assembled with side panels  12  and  18  being attached to lateral supports  36 , of which there are shown two, but there may be only one, or three or more. Each lateral support  36  has connection points  25  at either end of the lateral support that connect first and second side panels  12  and  18  to lateral supports  36 . Each connection point has a pivot connection  28  and a releasable connection  34 . Pivot connection  28  permits pivotal movement of the side panels relative to lateral supports  36  about a pivot axis that is parallel to side panels  12  or  18  and perpendicular to lateral supports  36 . Releasable connection  34  is spaced from pivot connection  28  in a direction perpendicular to the pivot axis, and generally below pivot connection  28  to facilitate construction and operation. Releasable connection  34  is selectively releasable to permit side panels  12  and  18  to pivot about the pivot axis. Referring to  FIGS. 2 and 41 , lateral support  36  may have stands  52  that support the lateral support with pivot connection  28  above releasable connection  34 . In other embodiments, trench boxes  10  and  200  may be designed with pivot connection  28  below releasable connection  34 . Stands  52  may be integrally formed (not shown), removable (as shown in  FIG. 6 ), or retractable (as shown in  FIGS. 44 and 45 ). The number, location, and size of stands  52  may vary depending on the requirements or preferences of the user. Stands  52  permit lateral supports to remain upright on a ground surface. If lateral supports were suspended from above, stands  52  may not be required. 
     Small Format Trench Box 
     Referring to  FIG. 1 , smaller inner faces  14  and  20  have upper attachment points  24  and  26 , respectively. Upper attachment points  24  and  26  are the first part of a two-part upper attachment  28 . Inner faces  14  and  20  also have lower attachment points  30  and  32 , respectively. Lower attachment points  30  and  32  are the first part of a two-part lower attachment  34 . 
     Trench box  10  is assembled and secured using lateral supports  36 . As shown in  FIG. 1 , trench box  10  has two lateral supports  36 . It will be understood that, depending on the application and factors such as the length of trench box needed  10 , there may be only one lateral support  36 , or additional lateral supports  36  may be used. Referring to  FIG. 2 , lateral support  36  has a first side support  38  and a second side support  40 . Side supports  38  and  40  are separated and stabilized by lateral supports  36 . Lateral supports  36  may be formed from two separate lateral components  42  as shown in  FIG. 2 . Lateral supports  36  maintain first side support  38  in a fixed position and orientation relative to second side support  40 . Side supports  38  and  40  may be fixedly attached to lateral supports  36 , removable, or pivotally movable relative to lateral supports  36 , as will be described elsewhere. As shown in  FIG. 2 , lateral supports  36  may be length-adjustable to adjust the spacing between the first and second side supports. Once the length has been adjusted, lateral supports  36  maintain the relative positions of side supports  38  and  40  at the desired spacing. Alternatively, lateral supports  36  may be of a fixed length and constructed as a single piece, as shown in  FIG. 9 . In this case, different sizes of lateral supports may be provided to allow for different sizes of trench boxes. 
     First and second side supports  38  and  40  have upper attachment points  44  and  46 , respectively. Upper attachments points  44  and  46  are the second part of the two-part upper attachments  28 , and pivotally engage the first parts  24  and  26  of upper attachments  28 . First and second side supports  38  and  40  also have lower attachment points  48  and  50 , respectively. Lower attachments points  48  and  50  are the second parts of the two-part lower attachments  34 , and fixedly engage the first parts  30  and  32  of lower attachment  34 . Each of upper attachment  28  and lower attachment  34  selectively engage and disengage. Upper attachment  28  and lower attachment  34  may be a variety of types of connections, as will be understood by a person skilled in the art. For example, either or both of upper attachment  28  and lower attachment  34  may be pin connected, as shown. In one example, referring to  FIG. 8 , second parts  48  and  50  of lower attachment  34  have an engagement surface  54 , such as an angled face in a preferred example, and first parts  30  and  32  of lower attachment  34  have a receiver  56  having a pin  58  that slides along engagement surface  54  to retain engagement surface  54  where it is received within receiver  56 . Upper attachment  28  is a pin connection, which permits a pivotal movement, and lower attachment  34  also preferably has a pin connection to provide an additional connection point, while engagement surface  54  and pin  58  provide a tighter and stronger connection. While the drawings show engagement surfaces  54  on lateral supports  36  and pin  58  on panels  12  and  18 , it will be understood that this could be reversed, e.g. with engagement surfaces  54  on panels  12  and  18  and pins  58  could be on lateral supports  36 . 
     In another example, either or both of upper attachment  28  and lower attachment  34  may be spring loaded attachments as shown in  FIG. 22  and  FIG. 23 . Referring to  FIG. 22 , upper attachment point  26  and lower attachment point  32  of second side panel  18  have brackets and posts  104  allowing them to be placed into spring loaded connectors  106  of upper attachment point  46  and lower attachment point  50 . As previously discussed, the brackets and posts  104  may also be carried by upper attachment point  44  and lower attachment point  50 , while upper attachment point  26  and lower attachment point  32  may be spring loaded connectors  106 . Referring to  FIG. 23 a   , upper attachment  28  is formed by engaging bracket and post  104  with spring loaded connector  106 . A safety pin  108  may then be inserted into opening  110  to prevent accidental disengagement of upper attachment  28 . Referring to  FIG. 23 b   , lower attachment  34  may be formed by engaging bracket and post  104  with spring loaded connector  106 . Safety pin  108  may be inserted into opening  112 . It will be understood that upper attachment  28  and lower attachment  34  may both be spring loaded attachments, or they may be used in combination with other attachments, such as those previously described. For example, upper attachment  28  may be a fixed attachment as shown in  FIG. 4 , while lower attachment  34  may be a spring loaded attachment as shown in  FIG. 23 b   . Other combinations may be used, as will be understood by those skilled in the art. 
     Trench box  10  further has stands  52  for supporting lateral support  36  in a vertical orientation with second parts  44  and  46  of upper attachments  28  above second parts  48  and  50  of lower attachments  34 . As shown in  FIG. 2 , stand  52  is removably attached to the second parts  48  and  50  of lower attachment  34 . However, it will be understood that stand  52  may also be shaped to be integrally formed with lateral support  36 , or may be attached to different areas of lateral support  36 , depending on the application. For example, stand  52  may be flanges that are attached to the sides or bottom of lateral support  36 , may be attached by a hinge such that they can be folded back, or lateral support  36  may have a flat bottom that is wide enough to stand on its own on some surfaces. Stand  52  is useful for allowing lateral support  36  to be self-supporting in order to facilitate the connection of upper attachments  28  between lateral supports  36  and panels  12  and  18  with lateral supports  36  in an upright position. As shown, stand  52  may be removably connected to second parts  48  and  50  of lower attachment  34 . Stand  52  may then be removed to allow lower attachment  34  to be connected. 
     Referring to  FIG. 4 , support stands  52  are preferably shorter than the height of panels  12  and  18 , and are connected below the upper edge of first and second panels  12  and  18  such that, when the first parts  12  and  18 , and second parts  44  and  46 , of the upper attachment  28  are connected and the stand  52  supports lateral support  36  on a ground surface, first and second panels  12  and  18  are angled downward and outward relative to lateral support  36 . Preferably, upper attachment  28  is positioned on first and second panels  12  and  18  such that a first distance between the first parts  24  and  26  of upper attachment  28  and a lower edge of the respective panel  12  or  18  is greater than a second distance between the second parts  44  and  46  of upper attachment  28  and the stand  52 . 
     Referring to  FIG. 6 , each lateral support  36  preferably has lifting lugs  60  that permit lateral supports  36  to be suspended by a lifting device (not shown) such as a crane, excavator bucket, etc. so that the panels  12  and  18  are free to pivot about upper attachments  28  when lateral support  36  is lifted sufficiently, i.e. to about the height of the panels  12  and  18 . 
     Referring to  FIG. 29 , trench box  10  may be assembled with additional panels connected to first and second side panels  12  and  18 . As shown in  FIG. 24 , trench box  10  may be assembled with one or more third side panels  62  that attach to and extend between first side panel  12  and second side panel  18 . Additional side panels may be attached using a variety of means, as will be understood by those skilled in the art. In the depicted embodiment, third side panel  62  is attached using a corner engagement member  64 , or bracket. Corner bracket  64  has perpendicular slots  66  as shown in  FIG. 25  that engage first and second side panels  12  and  18 , as well as third side panel  62 . It will be understood that, rather than perpendicular slots  66 , another type of engagement profile may be used, such as a pin connection against a flat surface or other clamping design that allows third side panel  62  to be held perpendicularly to first and second side panels  12  and  18 . 
     As shown in  FIG. 26 , third side panel  62  may also be attached to and extend above a top edge of one of the first and second side panels  12  and  18 . Third side panel  62  may be attached using a variety of engagement methods known in the art. As shown, third side panel  62  is attached to the top edge of second side panel  18  using an H-shaped engagement member  68 , or bracket, as shown in  FIG. 27 . Bracket  68  is described as being H-shaped because of the slots that receive the respective panels. It will be understood that bracket  68  may have a different type of engagement profile, as with corner bracket  64 , that secures third side panel  62  in the desired orientation and position; in this case, in parallel and in plane with first or second side panel  12  or  18 , as the case may be. 
     Referring to  FIG. 28 , first and second side panels  12  and  18  preferably have a universal engagement profile  65  on the perimeter of the panels that has a plurality of connection points that are evenly spaced along the outer peripheral edge of panels  12  and  18 . Preferably, the connection points extend along the entire peripheral edge as shown, but the connection points may also be only on a portion of each side, or a portion of one or more sides, as the case may be. A removable connector (not shown) is provided that engages engagement profile  65  in a selected location. Engagement profile  65  and the connector are designed such that the connector may be connected at one or more connection points (depending on the size and shape of the connector) at any point along engagement profile  65 . Engagement profile  65  allows panels  12  and  18  to have a universal connection system that allows a variety of connections to be made. For example, referring to  FIG. 29 , engagement profile  65  allows for trench box  10  to be assembled in a variety of configurations as needed using corner engagement member  64  or H-shaped engagement member  68  as shown. As shown, one panel is shown rotated 90 degrees to a portrait orientation as opposed to the landscape orientation. Engagement profile  65  also allows detachable connections to be made with other equipment, such as with accessories, safety devices, tools, sensors, etc. For example, referring to  FIG. 30 , first and second side panels  12  and  18  are shown as having a knife edge  100  attached using engagement profile  65 , which is useful when installing trench box  10  during excavation. In the depicted examples, the universal connector may be part of brackets  64  and  66 , or the universal connectors may mount to, or extend through, brackets  64  and  66 . 
     Referring to  FIG. 18  and  FIG. 19 , panels  12 ,  18 , and  62  are preferably designed with a thin outer wall  71  and an internal lateral support  70 , such as a diamond shape as shown in  FIG. 19 . This allows panels  12 ,  18 , and  62  to be lighter, while still being able to withstand the necessary loads. 
     Method of Assembly—Smaller Format 
     Referring to  FIG. 2  through  FIG. 8 , a method of assembling trench box  10  will be described. Lateral supports  36  are assembled, as required, and in the case that lateral supports  36  have length-adjustable lateral supports  36 , lateral supports  36  are adjusted to provide the required separation between first and second side supports  38  and  40 . Lateral supports  36  may be adjusted with a pin connection as shown, or with any other length-adjustable connection known in the art, such as threadably adjustable connections, hydraulically adjustable connections, etc. Lateral supports  36  are installed into stands  52 , which may be formed with lateral supports  36 , or, as shown, may be removably connected. As shown, stands  52  are secured to lateral supports  36  with lock pins  78 . Referring to  FIG. 3 , lateral supports  36  are positioned in spaced relation with a spacing  80 , as required for the application, and in a vertical orientation on stands  52 . Spacing  80  will be determined by the dimensions of the first and second side panels  12  and  18 , and specifically, by the distance between upper attachment points  24  and  26 , as well as the distance between lower attachment points  30  and  32 . Referring to  FIG. 4 , side panels  12  and  18  are then set against lateral supports  36  such that upper attachment points  24  and  26  engage with upper attachment points  44  and  46  to form upper attachments  28 . Panels  12  and  18  may need to be manipulated by a crane or other lifting device, or may be light enough to be manipulated manually by workers. When connected, upper attachments  28  form a pivotal attachment  82 , as shown. Pivotal attachment  82  may be formed by inserting a pin connector  90  into a pin receiver  92 , or upper attachments  28  may be otherwise designed with a hinge, and has sufficient movement to allow panels  12  and  18  to be at an angle that still allows lateral supports  36  to rest on the ground. Upper attachments  28  are positioned toward the top of each of the first and second panels  12  and  18  and toward the top of the lateral supports  36 . As shown in  FIG. 4  and  FIG. 5 , when attached, first and second side panels  12  and  18  are angled down and away from lateral supports  36  and rest on the ground surface. Upper attachments  28  preferably have a safety latch  84  in addition to pivotal attachment  82 , and safety latch  84  preferably has a lock pin  86  to prevent accidental disengagement of safety latch  84  and pivotal attachment  82 .  FIG. 20  and  FIG. 21  show one embodiment of a safety latch  84  in a closed positon and an open position, respectively. 
     Referring to  FIG. 6 , a lifting device, such as a crane, excavator bucket, or other device known in the art and represented by lifting sling  102 , may then be attached using lifting lugs  60 . When stands  52  are removably attached to lateral supports  36 , the connection between lateral supports  36  and stands  52  are disengaged. As shown, lock pins  78  are removed from stands  52 , and lateral supports  36  are lifted. As shown, this results in first and second panels  12  and  18  pivoting about upper attachments  28  toward the lateral supports  36 . As shown in  FIG. 7 , when lateral supports  36  are lifted sufficiently, first and second panels will contact lateral supports  36  and will be vertically oriented. Stands  52  may be removed by disconnecting them once panels  12  and  18  are attached, such that lateral supports  36  are lifted out of stands  52  as sling  102  lifts trench box  10 . Referring to  FIG. 8 , lower attachment points  30  and  32  of first and second panels  12  and  18  contact lower attachment points of  48  and  50  at a point below pivotal attachment  82 . Receiver  56  of lower attachment points  30  and  32  receives angled surface  54  of lower attachment points  48  and  50 . Pin  58  can be slid into receiver  46  and slides along angled surface  54  to provide a tight angled lock connection, retaining angled surface  54  within the retainer. Lower attachment  34  also preferably has a locking pin  88  to prevent accidental disengagement of lower attachment  34 . Lower attachment  34  may initially be formed by inserting pin connector  94  into pin receiver  96 . Pin connector  94  may be the same as locking pin  88 , or separate pin connectors may be provided, depending on the requirement of the application.  FIG. 20  and  FIG. 21  also show one embodiment of an angled lock connection in a closed positon and an open position, respectively. Trench box  10  is then inspected to ensure that all attachments are secure, all safety pins and latches are properly installed, and the angled lock is tight. Trench box  10  may then be lowered into the trench  11  formed in ground surface  13 , as shown in  FIG. 7A . 
     Additional panels may also be installed on trench box  10 , depending on the application. For example, one or more third side panels  62  may be attached by sliding corner engagement members  64  onto the sides of first side panel  12  and second side panel  18  and only third side panel  62 , or by sliding H-shaped engagement member  68  onto the top edge first side panel  12  or second side panel  18  and inserting third side panel  62 . This may be done to create an enclosed trench box  10 , a box with higher sides, or even, by attaching panels of different sizes, an enclosed trench box  10  with access openings. As can be seen, the components described above allow for a modular trench box  10  design, where the ultimate size, shape and configuration can be designed according to the requirements of the situation. 
     Method of Disassembly—Smaller Format 
     Referring to  FIG. 10 through 17 , disassembly of trench box  10  will now be described with respect to a variation of lateral supports  36 . It will be understood that the assembly procedure described above and the disassembly procedure described below are applicable to these and other possible variations of lateral supports  36 . It will also be understood that other methods of assembly and disassembly may also be used, according to the preferences of the user, and the ultimate design of trench box  10  and its component parts. In particular, the attachment points described above and below are those provided at convenient locations for manipulating trench box  10 , however it will be understood that other attachment points or lifting strategies may be used. 
     Trench box  10  is lifted out from the trench using sling  102  attached to lifting lugs  60 . Once trench box  10  is on a ground surface, trench box  10  is then rotated using corner lift points  98  as shown in  FIG. 10 . Alternatively, trench box  10  could also be rotated on its side using lifting lugs  60  or other attachment points, according to the preferences of the user. Trench box  10  is first positioned on one side, as shown in  FIG. 11 , and the corner lift points  98  are changed, as shown in  FIG. 12 , allowing trench box  10  to be placed upside-down as shown in  FIG. 13 . After placing trench box  10  upside down, corner lift points  98  are detached from the lifting device. 
     Referring to  FIG. 14 , pin  58  is then slid away from angled surface  54 , allowing the angled lock connection to be disengaged. Next, locking pin  88  can be removed, allowing lower attachment  34  to be detached. Referring to  FIG. 15  and  FIG. 16 , this allows first and second panels  12  and  18  to pivot about upper attachments  28  and be laid flat onto the ground surface. This may be accomplished through the use of the lifting device and the corner lift points  98  in order to control the decent of first and second panels  12  and  18 . Referring to  FIG. 17 , lock pins  86  may then be removed, and safety latch  84  may be disengaged, such that upper attachments  28  are disconnected, and lateral support  36  may be lifted away from first and second panels  12  and  18 . In all cases above, lock pins may be reinserted after the connections are detached for storage of the lock pins. 
     Referring to  FIG. 31 through 36 , an alternative method of disassembly of trench box  10  will now be described. The variation will be described with respect to spring loaded upper attachment  28  and lower attachment  34 , however, it will be understood that the method of disassembly may be used with other forms of upper and lower attachments  28  and  34  as described, such as a manually operated attachment as described below with respect to the large format trench box  200 . 
     Referring to  FIG. 31 , trench box  10  is lifted out from the trench using sling  102  attached to lifting lugs  60 . Referring to  FIG. 32 , once trench box  10  is on a ground surface, trench box  10  is rotated using lifting lugs  60  to be placed on its side as shown in  FIG. 33 . Sling  102  may then be attached to corner lift points  98 , and safety pins  108  may be removed from openings  112  of lower attachment  34 , and the spring loaded connector  106  of lower attachment  34  can be released. Using sling  102  or other means, side panels  12  and  18  may then be released to pivot about upper attachments  28  and be laid flat on the ground as shown in  FIGS. 34 and 35 . Sling  102  may be attached to lifting lugs  60 , safety pins  108  may be removed from openings  110  of upper attachment  28 , and the spring loaded connector  106  of upper attachment  28  can be released to allow lateral support  36  to be lifted away from first and second panels  12  and  18  as described above. It will be understood that different assembly and disassembly methods will be used depending on the circumstances and the needs of the user. For example, the second described disassembly method may be preferred when the spacing between side panels  12  and  18  is small enough that lower connections  34  may be disengaged from ground level, while the first described disassembly method may be preferred when the spacing between side panels  12  and  18  is larger and it is preferred to turn the trench box  10  entirely upside down. 
     Larger Format Trench Box 
     In some circumstances, a larger trench box is required than those depicted and discussed above, such as one that may have a high arch that has sufficient clearance to allow vehicles or equipment to pass below. However, an increase in size results in an increase in weight and safety requirements for assembly and disassembly. A variation on the smaller format trench box  10  will now be described. It will be understood that a larger format trench box  200  may be designed that incorporates various features described above with respect to smaller format trench box  10 , and that various features described below with respect to larger format trench box  200  may also be incorporated into smaller format trench box  10 . 
     Referring to  FIG. 37-41 , setting aside size, the main differences in design between trench box  200  and trench box  10  discussed above are the design of connection points  25  and the use of snubbers  226 . With trench box  10 , connection points  25  are between lateral support  36  and side panels  12  and  18 , via side supports  38  and  40 , which are fixedly mounted to lateral supports  36  such that side panels  12  and  18  pivot relative to lateral supports  36  and side supports  38  and  40 . With respect to trench box  200 , connection points  25  are between lateral support  36  and side supports  38  and  40 . In each case, side supports  38  and  40  are removably attached to, and extend alongside panels  12  and  18  in a direction perpendicular to the pivot axis of pivot connections  28 . 
     Referring to  FIGS. 48 and 49 , releasable connection  34  is depicted as a manually operated latch  220  that is operated by a lever  221 , as shown in  FIGS. 42 and 43  engages a pin  222 . As latch  220  engages pin  222 , side panels  12 / 18  are locked in position, and when latch  220  is lifted out of engagement with pin  222 , side panels  12 / 18  are permitted to rotate, as shown in  FIG. 40 . Latch  220  may also be spring-loaded, depending on the preferences of the user. 
     Referring to  FIG. 37 , lateral supports  36  are preferably length adjustable, which may be accomplished by removing pins  224  or bolts, sliding the sections of lateral supports  36  apart, and replacing pins  224  in the desired openings once the desired size has been reached. 
     Referring to  FIGS. 44 and 45 , trench box  200  is also provided with a snubber  226  at each connection point  25 , which is used to control the pivotal movement of panels  12  and  18  relative to lateral supports  36 . Snubbers  226  are positioned between lateral supports  36  and side panels  12 . Snubbers  226  may be directly between lateral supports  36  and side panels  12 , or between lateral supports  36  and side supports  38 / 40 . As trench box  200  is designed to be larger and heavier, snubbers  226  are used to reduce the speed at which panels  12  and  18  will pivot to reduce the risk of damage or injury during disassembly. Snubbers  226  are generally not required for assembly due to the decrease in risk, although there may be some designs in which that could be useful. As shown in  FIG. 46 , snubbers  226  are hydraulic cylinders with a flow restrictor that only allows a certain flow rate, which slows the motion of panels  12  and  18  relative to lateral supports  36 . As used herein, the term “snubber” refers to any type of device that can be used to control or slow the movement. Other types of snubbers may include different types of hydraulic snubber designs, mechanical snubbers, magnetic snubbers or electrically powered snubbers, etc. Alternatively, in other embodiments, snubbers  226  may be controlled by an external power source, and may be used as actuators that assist in the assembly and disassembly of trench box  220  by applying a force to pivot panels  12  and  18  relative to lateral supports  36  toward and away from the assembled position. This may avoid or reduce the need for other lifting equipment. 
     Method of Assembly—Larger Format 
     Referring to  FIG. 37-41 , the steps in the assembly of trench box  200  is shown. The steps are similar to the method of assembling the smaller format trench box  10 , except that panels  12  and  18  are first mounted to side supports  38  and  40  as shown in  FIGS. 38 and 39 , and connection points  25  are connected between side supports  38 / 40  and lateral supports  36  as trench box  200  is lifted. Given the weight and size of trench box  200 , it may be preferable to lift one side at a time, as shown in  FIG. 40 , rather than both at the same time as described above, to reduce any possibility of damage or injury. As with smaller format trench box  10 , this will depend on the available equipment and the preferences of the user. Once no longer required, stands  52  are pivoted up and out of the way, as shown in  FIGS. 44 and 45 , at a convenient time during the process. 
     Method of Disassembly—Larger Format 
     The method of disassembling larger format trench box  200  is different than the method described with respect to smaller format trench box  10 . Rather than lifting one side panel  12  or  18  and essentially rolling trench box  10  upside down, the steps of assembling trench box  200  is merely reversed, where side panel  18  (or  12 ) is released and lowered to the position shown in  FIG. 40 . This may be done by releasing releasable connection  34 , and applying a force on side panel  18 , such as a pulling force, a lifting force, or combination thereof to cause the bottom edges of panels  12 / 18  to move away from each other such that panels  12 / 18  extend at an angle downward and away from lateral support  36 . The other side panel  12  (or  18 ) may then be released and lowered to the position shown in  FIG. 39 . Side panels  12  and  18  can then be disconnected and removed from lateral supports  36 . Side panels  12  and  18  may be pivoted outward individually, or at the same time. 
     Universal Connection System 
     Referring to  FIGS. 24-30  and  FIGS. 50-65 , a universal connection system for both the smaller format and larger format trench box will be described. It will be understood that elements of this connection system may be incorporated into any of the trench boxes described above, and that the universal system may also be used with other styles of trench boxes that do not operate as above. 
     As discussed above, referring to  FIGS. 24-30 , trench box  10  may be assembled with additional panels connected to first and second side panels  12  and  18 , and may have one or more third side panels  62 . It will be understood from the description above, and from the details provided below, that the side panels may be provided in a variety of different configurations, and may not be assembled or disassembled as described above. The description below will refer to side panels  300  generally, which may include first and second side panels  12  and  18 , third side panels  62 , or other side panels as desired. As depicted, side panels  300  are preferably planar. Side panels  300  are connected together using a universal engagement profile  302 , having equally spaced connection points  316  positioned around the outside perimeter of side panels  300 . This type of engagement profile  302  was described above with respect to universal engagement profile  65 . While the connection points  316  are provided on the four sides of panels  300 , side panels  300  may also be provided with additional attachment points  322  as discussed further below. Trench box  10  is then assembled with the use of connecting brackets  304 . 
     Referring to  FIG. 50 , trench box  10  is shown with four side panels  300  connected with ninety degree angled connecting brackets  304 , as shown in  FIG. 25 . It will be understood that similar structures can be formed using other angles between the receiving slots  306  ( FIG. 64 ) of the connecting brackets  304 . For example, receiving slots  306  may be angled to form triangular trench boxes having three sides  300 , or to form trench boxes having five, six, or eight sides  300 . It will be understood that the number of sides  300  will be determined based on the particular application and the needs of the user. As shown in  FIG. 50 , trench box  10  has two vertically spaced connecting brackets  304  on each corner of trench box  10 . However, it will be understood that trench box  10  may be connected by a single connecting bracket  304  on each corner, or with multiple connecting brackets  304  on each corner, depending on the application. 
     Referring to  FIG. 51 , trench box  10  is shown with connecting brackets  304  spanning between lower and upper side panels  300 . Placing the bracket  304  between side panels  300  both vertically and horizontally results in a connection between a single bracket  304  and four side panels  300 . This allows trench box  10  to be built up vertically as high as may be needed for the application, and provides structural strength to the connection as connecting bracket  304  spans a portion of each of the panel. Referring to  FIG. 53 , providing engagement profile  302  on the four sides of side panels  300  also allows for the orientation of side panels  300  to be varied, while still attaching with connecting bracket  304 . The panels shown making up trench box  10  are all the same size, with two horizontally oriented panels making up each of the long sides of trench box  10 , and one vertically oriented panel making up each of the short sides of trench box  10 . As shown, the two end panels on the short sides are vertically offset from the panels of the short sides. Engagement profile  302  allows for panels to be connected at any of the points along engagement profile  302 , which permits vertical and horizontal offsets of panels. 
     Referring to  FIG. 52 , the details of connecting bracket  304  connecting to engagement profile  302  is shown. Connecting bracket  304  has a receiving slot  306  that receives engagement profile  302 . Pins  308  are then inserted into the openings of engagement profile  302 . Referring to  FIG. 54 , connecting bracket  304  may also be provided with one receiving slot  306  to connect vertically stacked panels  300  together. This allows multiple side panels  300  to be stacked when trench box  10  is formed with only first and second side panels  12  and  18  as described above.  FIG. 55 through 58  depict an example of a connecting bracket  304  having only one receiving slot  306  and pin connectors  308 . Pin connectors  308  may be provided with a locking engagement, such as a spring-biased pin or locking dowel  310 . Also depicted in  FIG. 55 - FIG. 59  is lifting lug  320 , which may be used to move panels  300  or trench box  10  as described further below. As shown in  FIG. 55 , where pin connectors  308  are provided with a locking dowel  310 , a profile may be provided on the pin receiving opening  312  of the connecting bracket  304 . Locking dowel  310  can be oriented such that it faces towards the point  314  of the profile. Referring to  FIG. 56 , point  314  may also be a slot as shown instead of a smooth profile. Locking dowel  310  may be inserted such that locking dowel  310  of pin  308  faces towards slot  314 . Referring to  FIGS. 57 and 58 , once locking dowel  310  is passed through bracket  304  it can be rotated to no longer line up with slot  314 , thereby preventing removal of pin  308 , as shown in  FIG. 58 . Referring to  FIG. 59 , engagement profile  302  of side panels  300  may be provided with diamond shaped openings  316  that allow locking dowel  310  to pass through openings  316  in different orientations, allowing for different connections to be formed with engagement profile  300 . 
     Referring to  FIG. 60  and  FIG. 61 , engagement profile  302  may be used to form detachable connections with other equipment, such as with accessories, safety devices, tools, sensors, etc., as described above.  FIG. 60  shows a side panel  300  having extension feet  318 . Extension feet  318  may be used, for example, to lift side panel  300  off of the ground surface, or to allow passage of tubes or cables underneath side panel  300 .  FIG. 61  shows the attachment of a knife edge  100  as shown in  FIG. 30 . Knife edge  100  is attached using pins  308  as shown. In the depicted example knife edge  100  is attached to additional attachment points  322 , although it will be understood that knife edge  100  may also be attached to connection points  316 . As shown, additional attachment points  322  are provided along two sides of panel  300 . However, they may also be provided on all four sides, or on only one side, etc., as required by the application. Additional attachment points  322  may be provided for the connection of other accessories, as discussed above. Referring to  FIG. 62  and  FIG. 63 , connecting bracket  304  may have two receiving slots  306  in parallel as shown, allowing for panels  300  to be connected inline in order to provide longer panels. As shown, two panels  300  are connected together using one h-shaped connecting bracket  304  that receives the engagement profile  302  on the end of each panel  300 , and top and bottom connecting brackets  304  that receive a portion of the top engagement profile  302  and span the two panels. 
     Referring to  FIG. 64  and  FIG. 65 , further details of the connection between receiving slots  306  of connecting bracket  304  and engagement profile  302  are shown. Referring to  FIG. 64 , engagement profile  302  is received within receiving slot  306  as shown. Referring to  FIG. 65 , pins  308  engage with pin receiving openings  312  on connecting bracket  304 , as well as openings  316  of engagement profile  302  on side panel  300 . The U-shaped receiving slot  306  of connecting bracket  304  engages with both sides of engagement profile  302  of side panel  300 , providing structural strength to the connection and supporting against forces applied to side panel  300  from either direction. Additional connection points  322  may also be provided in order to stabilize side panels  300  using additional connectors, such as bracket  68 , shown in  FIG. 26  and  FIG. 27 , and previously described. 
     Assembly and use of trench box  10  will now be described with reference to  FIG. 51 . It will be understood that the principles described here may also be applied to the small format and large format trench boxes as described above, and any combination of assembly techniques may be used. Trench box  10  may be assembled without the use of lateral supports and pivoting attachments for some applications, such as where the required trench box  10  is relatively small, and lightweight side panels  300  may be used, which can be assembled by hand. Trench box  10  may be assembled by attaching connecting brackets  304  to the engagement profile  302  of a first side panel  300 . Connecting brackets  304  are slid over engagement profile  302  such that engagement profile  302  is received within the receiving slot  306  of connecting bracket  304 . The pin receiving openings  312  on connecting bracket  304  are aligned with openings  316  on engagement profile  302 . Pins  308  are then inserted through openings  312  and  316 , and may be locked in place using locking dowel  310 , or other locking techniques, such as by applying a standard pin and receiver arrangement as is known in the art. The first side panel  300  may be vertical, or it may be placed horizontally on a ground surface with the outer face contacting the ground surface to allow connections to be formed without the requirement to support first side panel  300 . Once connecting brackets  304  have been attached to first side panel  300 , another side panel  300  may be connected to the connecting bracket  304  on any of the sides of first side panel  300 . It will be understood that trench box  10  may be assembled while on an outer face of a side panel  300 , or it may also be assembled while standing on an edge of engagement profile  302 . Panels  300  may be assembled vertically on top of other panels  300  as shown in  FIG. 51 , or horizontally beside other panels  300  as shown in  FIG. 62  and  FIG. 63 . Panels  300  may also be assembled in different orientations and alignments, as shown in  FIG. 53 . When manipulating panels  300  and trench box  10 , lifting lugs  320  provided on connecting brackets  304  may be used. For example, after assembly of trench box  10 , a crane or other lifting machinery may be connected to lifting lugs  320  to allow trench box  10  to be lifted and lowered into a trench  11 , as shown in  FIG. 7A , or other excavation to provide required shoring. Providing lifting lugs  320  on connecting bracket  304  allows connections to be formed on various positions on trench box  10 , allowing different configurations of trench box  10  to be manipulated. 
     In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there be one and only one of the elements. 
     The scope of the following claims should not be limited by the preferred embodiments set forth in the examples above and in the drawings, but should be given the broadest interpretation consistent with the description as a whole.