Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to a trench shoring assembly and, in parti-
cular, to a trench shoring assembly known as a trench box. This application
is a division of copending application 270,911, filed February 2, 1977.
Trench boxes are typically used in excavation work when pipe is being
laid, such as sewer or drain conduit. Basically, a trench box consists of two
walls spaced apart a fixed distance from each other by a plurality of spreader
devices affixed to and perpendicular to each side wall. Assembled trench boxes
are positioned in an excavated hole or trench and pipe is laid within the trench
box and after each length of pipe is laid the trench box is moved along the
trench for laying the next length of pipe. The side walls of the trench box
keep the excavation free from earth which has a tendency to fall or cave into
the excavated hole or trench before and during the laying of the pipe.
Prior trench boxes are typically rigid. That is, the spreader pipes
rigidly interconnect the spreader walls when in use. Rigid trench boxes often
stick in the ground due to the side ~all pressures from caved in earth during
normal trench box lifting-out procedures. A rigid trench box is also difficult
to position within an excavated trench.
Some trench shoring devices allow for complete pivotal movement bet-
ween the spreader pipes and the side walls while the trench box is being
positioned within the trench butJ upon being positioned within the trench, the
spreader pipes and the side walls are then rigidly attached or made rigid.
In accordance with the subject invention, there is provided a trench
shoring assembly comprising: a pair of spaced wall means, connecting means
interconnecting said wall means including support means extending from said
wall means and spreader means extending between said support means and
connecting means removably connecting said spreader means to said support
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means, and lifting means supported by said connecting means for lifting
said assembly upon being connected to a raising means, said lifting means
including a plurality of closed-looped ring members surrounding said connecting
means with at least a lifting portion thereof in spaced relation to said
connecting means for connection to the raising means, said spreader means in-
- cluding at least one spreader pipe extending between said support means of said
spaced wall means, said connecting means including pins connecting said spreaderpipes to said support means and limiting movement of said ring members longi-
tudinally of said spreader pipe when in engagement therewith.
Other advantages of the present invention will be readily appreciated
- as the same becomes better understood by reference to the following detailed
description when considered in connection with the accompanying drawings
wherein;
Figure 1 is a perspectiye ~iew partially broken away and in cross
' section of a trench shoring assembly;
Figure 2 is a front Yiew of the trench shoring assembly showing
relatiYe movement between the side walls and the connecting means in phantom;
Figure 3 is a fragmentary view partially broken away and in cross
: section showing the interconnection between a spreader pipe and a support means;
Figure 4 is a fragmentary view taken substantially along line 4-4 of
Figure 3 and particularly showing the elongated slot formed in the spreader
pipe;
Figure S is a fragmentary cross-sectional view showing the lower
extremity of a side wall;
- ~igure 6 is a front view of a ring member or lifting ring;
Figure 7 is a fragmentary perspective view showing lug means inter-
connecting a set of stacked side walls;
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Figure 8 is a fragmentary perspective view showing the lifting rings
attached to the connecting means for lifting the trench shoring assembly;
Figure 9 is a fragmentary end view of the bottom end of a side wall
showing a guard means disposed on the end of the lower extremity of the wall
means; and
- Figure 10 is a fragmentary, cross-sectional, side view of the guard
means of Figure 9 disposed on the end of the lower extremity of the wall means.
; DESCRIPTION OF THE PREPERRED EMBODIMENT
Referring now to the drawings, a trench shoring assembly or trench
box assembly is generally shown at 10 in Figures 1 and 2. The trench box assem-
bly 10 includes a pair of identically constructed spaced wall means or side
walls each generally indicated at 12. The side walls 12 are disposed vertically
within a trench to prevent cave-in of the side walls of the trench or hole as
pipe is laid between the side walls 12.
The trench box assembly 10 also includes connecting means generally
shown at 14 for allowing limited pivotal movement between the side walls 12.
The limited piYotal movement allowed between the side walls 12 is illustrated
in phantom in Figure 2. The connecting means 14 includes support means general-
ly s;hown at 16 which are rigidly attached to each of the side walls 12.
Spreader means comprising the cylindrical spreader device or pipes 18 extend
between the support means 16 and space the side walls 12 apart.
As illustrated in ~igure 1, each side wall 12 is defined by inter-
connected structural members which define a main frame generally indicated at
20. ~any of the structural members defining the frame 20 are hollow metal
beams generally rectangular in cross section with rounded corners. One of the
hollow structural metal beams is a top beam 22 which extends longitudinally
along the top of each side wall 12. A force transferring means such as a hard-
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wood insert 24 is disposed within the top beam 22 for preventing the collapse
of the top beam 22. ~len the trench box assembly 10 is placed in a trench, the
top of the side walls 12 are pounded to drive the side walls into the earth.
The hardwood insert 24, which could be made of other equivalent materials,
prevents the collapse of the top beam 22 and transfers such forces to the
remaining frame members.
The frame 20 further includes vertical hollow beams 26 which extend
perpendicularly to and are connected to the top beam 22 and transfer the above-
described pounding forces to the lower structural members. The frame also
includes the solid ribbed plate members or ribbed members generally shown at
28 and which also extend perpendicularly to and are connected to the top beam
22. The ribbed plate member 28 provides additional structural support to the
side walls 12 and are optional. Each ribbed plate member 28 includes a verti-
cally extending ribbed portion 30 extending perpendicularly to the top beam 22
and a flanged portion 32 extending perpendicularly from the ribbed portion 30.
A metal strip member 34 is attached by welding to the flanged portions 32 of
adjacent ribbed members 28 to interconnect the ribbed members 28. The strip
member 34 is also welded to the vertical beams 26.
A metal plate means is connected to the frame 20 at its inner and outer
face. ~ore particularly, the metal plate means includes one or more outer metal
plates 36 and one or more inner metal plates 38 welded to the structural members
o the frame 20, thereby rendering the interior of a side wall 12 air-tight.
The strip member 34 which is disposed approximately midway between
the ends of the ribbed members 28, provides a greater surface area to which the
upper inner metal plate 38 may be welded.
The frame 20 also includes intermediate horizontally extending beam
members 40. The intermediate beam members 40 extend parallel to the top beam 22
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and perpendicular to the vertical beams 26 to provide added structural strength
to the frame 20. The ends of the side walls 12 are defined by vertically
disposed hollow beam members generally shown at 39 which extend from the top
of each side wall 12 to the top of the triangular bottom portion or lower
extremity. These vertical structural members 39 are also generally rectangular
in cross section and have rounded corners. The metal plates 36 and 38 are
welded to the side of the vertical structural member 39, the edge of the metal
plates 36 and 38 being disposed rearwardly from the end face 41 of the vertical
structural member 39 as shown in ~igure 10.
As seen in cross section in Figure 5, each side wall 12 has a tapered
bottom portion which defines a triangularly shaped pointed lower extremity.
This pointed lower extremity extends between the ends of the side walls 12.
One of the structural members of the main frame 20 is a horizontally extending
bottom beam member 42 which extends horizontally along the bottom of the side
wall 12 and above the triangularly shaped pointed lower extremity. A portion of
the lower outer metal plate 36 extends vertically downwardly from the horizon-
tally extending bottom beam member 42 and forms one side of the triangularly
shaped pointed lower extremity. The bottom extremity of the lower inner metal
plate 38 is bent inwardly to define the other side of the trian~ularly shaped
lower extremity to thereby complete the triangular shape.
The trench box assembly lQ further includes guard means, such as
corner shoes generally shown at 43 in Figures 1 and 2, which are disposed at
; each of the bottom corners or ends or the side walls 12. The corner shoes 13
are disposed at and encase each of the bottom ends of the side walls 12 thereby
proYiding these bottom ends with protection against abrasion. The corner shoes
43 are made of cast or forged metal to provide the necessary durability to
resist wear, as these corner ends o the side wall 12 often receive the greatest
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amount of wear due to dragging the trench box assemhly 10 over rough surfaces
such as gravel. The corner shoes 43 are comprised of a triangular member having
a triangular front face 44 and side flanges 46 which extend rearwardly from the
front face 44 along two sides of the front face 44. The two side flanges 46
come together at the bottom of the corner shoe to form a knife-like cutting
edge to allow the lower extremtity~of the trench box assembly 10 to be more
easily positioned into the ground. The side flanges 46 are disposed in over-
lapping relationship to the metal plates 36 and 38 and are disposed exteriorly
of the metal plates 36 and 38. The corner shoes 43 are welded to the vertical
beam 39 and the metal plates 36 and 38.
Instead of corner shoes 43, the guard means may comprise an end gusset
such as that generally shown at 48 in ~igures 9 and 10. The end gusset 48 also
includes a triangular front face or wall 44' and side flanges 46' which extend
rearwardly from the front face 44' along two sides of the end gusset 48. The
side flanges 46' of the end gussets 48 are disposed in overlapping relationship
with the metal plates 36 and 38 and the side flanges 46' are disposed interiorly
of the metal plates 36 and 38. The end gus-sets 48 also include a tongue 49
extending upwardly from the front wall 44' for overlapping the lower end of the
adjacent vertical beam 39.
The end gusset 48 has a threaded hole 50 through the front face or
wall 44', the hole 50 being in fluid communication with the interior of the side
wall 12. As shown in ~i`gures 9 and 10 removable plug means comprising a plug 52
is threadedly disposed in the hole 50 to prevent the flow of any fluid through
the hole 50. The side walls 12 are fabricated so as to be water-tight, however,
; they may, after wear and tear, leak. As alluded to above, both the corner shoes
43 and the end gussets 48 are welded in watertight relationship to the vertical
beams 39 and the metal plates 36 and 38. If water leaks into the side wall 12,
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the plug 52 ma~ be removed to enable the water to drain out through the hole
50. The end gusset 48 is provided with a raised boss 54 at the back surface
of the front face 44' and the hole 50 extends through the boss 54 to establish
fluid communication with the interior of the side wall 12.
An abrasion protection means or metallic bar 56 is disposed at the
pointed lower extremity of the side walls 12 and extends between the ends of the
side wall 12. The metallic bar 56 protects the bottom of the side wall 12
against abrasion and preferably comprises "Suralloy 500" an 8630 modified steel.
A plurality of triangularly shaped gusset plates, generally shown at 58, are
horizontally spaced along the lower extremity and extend downwardly from the
,~ horizontally extending bottom beam member 42 to a pointed lower end. The
pointed lower end of each gusset plate 58 has a notch 60 formed therein in which
the metallic bar 56 is disposed. T~e gusset plates 58 are welded to and hold
the metallic bar 56 at a number of po~itions along the lower extremity of the
side wall 12 and the metallic bar 56 is also welded to and disposed between the
outer metal plate 36 and the inner metal plate 38.
As described above, each side wall 12 includes interconnected struc-
tural members which define a main frame 20. The support means 16 is rigidly
secured to the main frame 20 and is adapted to be connected to the spreader
pipes 18 for transferring forces from the spreader pipes 18 directly to the main
frame 20. The support means 16 includes a collar means or tubular spreader
collar 62 and a backing plate means generally indicated at 64 in Figure 1. The
spreader collars 62 extend from the side walls 12 and are adapted to be connect-
ed to the spreader pipes 18, the spreader pipes 18 extending between a pair
of opposed tubular spreader collars 62. The backing plate means 64 rigidly
secures the spreader collars 62 to the main frame 20 whereby forces applied to
the spreader collars 62 are transferred directly to the main frame 20. The
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hacking plate means 64 includes a-~-shaped member having a front wall 66 and
spaced side flanges 68 which extend rearwardly from the front wall 66. The
spreader collar 62 is welded to the front wall 66 and the side flanges 68 are
: welded to the main frame 20. The side flanges 68 extend rearwardly from the
front member 66 along the top and bottom sides of the front wall 66. The upper
side flange 68 of the upper U_shaped member adjacent the top beam 22 is welded
to the front wall 66 and extends rearwardly. The side flanges 68 are rigidly
secured to the main frame 2Q and~ in particular~ to the vertical beam 39 and
one of the vertical beams 26 by welding. The backing plate means 64 further
includes rib means comprising plates or support ribs 70 which extend vertically
between and are welded to the side flanges 68 for maintaining the position of
the side flanges 68 relative to each other as shown in Figure 1. The edges of
the walls 66 and the flanges 68 are welded to the beam members of the frame 20.
By providing so many welding points the U-shaped member and, consequently, the
,` entire support means 16, is rigidl~ secured to the side wall 12 at its main
' frame 20.
The ends:of the spreader pipes 18 overlap a portion of the spreader
collars 62 as best illustrated in ~igures 2, 3 and 4. The connecting means 14
includes a slot ~eans generally indicated at 72 extending through the overlapping
portions of the spreader pipes 18 and the spreader collars 62 as best illus-
trated in ~igure 4. Pin means generally indicated at 74 extend through the
slot means 72 and attach the spreader pipes 18 to the spreader collars 62. As
shown in F~gure 4, the slot means 72 is larger in part than the pin means 64 andallows the relatiYe pivotal moYement between the spreader collars 62 and the
spreader pipes 18. rn other words, the pin means 74 is allowed to move unencum-
hered to a limited extent along the slot means 72 in allowing the relative pivotal
'5 moYement between the 5preader pipes 18 and spreader collars 62. The slot means
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72 includes a hole 76 extending through each spreader collar 62 and an elon-
gated slot 78 which extends through the spreader pipes 18. The pin means 74
extend through both holcs 76 and elongated slots 78 and thereby attaches the
; spreader pipes 18 to the spreader collars 62.
A brace means comprising a pair of hori~ontally spaced structural
beams or plates 80 shown in ~igure 2 rigidly interconnect two adjacent spreader
pipes 18. The plates 80 which extend vertically between the vertically spaced
spreader pipes 18 are provided hecause the limited pivotal movement between the
spreader pipes 18 and the spreader collars 62 causes the spreader pipes 18 to
act as levers to produce a bending action on the spreader collars 62 which could
break the spreader collars 62 off their respective backing plate means 64. The
plates 80 tie two spreader pipes 18 together, the tied together spreader pipes
18 thereby exerting a straight pull or push action on the corresonding spreader
collars 62 and not a bending action.
As s,hown in Figure 1 and in ~igure 8, lifting means comprising closed
loop ring members generally shown at 82 are supported by the spreader pipes 18
and ~re provided for lifting the trench box assembly 10 upon being connected to
a rais,ing means such as hook on a cable extending from a crane. The ring
members 82 are slidably supported by the spreader pipes 18 so that the ring
; 20 members 82 may be positioned at a number of positions along the spreader pipes
18. As can be best seen in ~igure 6, the ring members 82 include a large radius
, portion 84 which engages the spreader pipe 18 and a smaller radius portion 86
which may be connected to the hook on a cable extending from the crane. Each of
' the ring members 82 may be formed by bending a metal rod into the configuration
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shown until its ends 88 overlap. The overlapping ends 88 are welded together.
These overlapping ends 88 are disposed along the large radius portion 84.
As previously noted, the pin means 74 interconnects the spreader pipes
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18 and the spreader collars 62. Th.e pin means 74 als.o limits the moYement of
the ring members 82 by only permitting the ring members 82 to move between
themselves and their corresponding adjacent side wall 12 along the spreader pipes
18.
~ igure 7 shows a second trench box assembly, generally shown at 90,
stacked upon the identical trench box assembly 10. Lug means such as a plurality
of flanges generally shown at 92 extend from the top-most spreader pipe 18 for
. attachment to mating lug means such as mating flanges 94 which extend from a
cylindrical spreader pipe 96 of a second connecting means. The second connect-
i ing means is associated with a second pair of side walls generally shown at 98,
only one of which is shown in ~igure 7. The flanges 92 have holes 100 there-
through.for receiving locking pins 102 to interconnect the flanges 92 with the
mating flanges 94 when the flanges 92 and 94 are aligned, the mating flanges 94
having holes 103 therethrough to also receive the locking pins 102. The flanges
92 include a pair of closely spaced flanges while the mating flanges 94 comprise
a single flange 94 which is disposed between the closely spaced flanges 92. The
locking pin 102 extends through the closely spaced flanges 92 and the single
flange 94 to interconnect the flanges and, thereby interconnect the stacked
trench bQx assemblies IQ and 90 at spreader pipes 18 and 96 respectively.
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