WO2023099906A1

WO2023099906A1 - Hydraulically operable trench shoring apparatus and its method of use

Info

Publication number: WO2023099906A1
Application number: PCT/GB2022/053061
Authority: WO
Inventors: Glenn MOLYNEUX
Original assignee: Autoshore Ltd
Priority date: 2021-12-03
Filing date: 2022-12-02
Publication date: 2023-06-08

Abstract

The present invention relates to a trench shoring apparatus (10), comprising: · first (12a) and second (12b) side panels having a top edge, a bottom edge and side edges, the first and second side panels being connected in a parallel spaced-apart configuration by a transverse strut being mounted proximate each side edge thereof and nearer the top edge than the bottom edge; and · actuator means (52) being operable to vary the length of the transverse strut from a first length to a second length.

Description

HYDRAULICALLY OPERABLE TRENCH SHORING

APPARATUS AND ITS METHOD OF USE

TECHNICAL FIELD OF THE INVENTION

This invention relates to a hydraulically operable trench shoring apparatus and its method of use. In particular, this invention relates to a hydraulically operable trench shoring apparatus that can be transported and deployed in a trench under the control of an operator who is situated entirely remotely from the trench. The hydraulically operable trench shoring apparatus provides a rapidly deployable temporary earth retaining structure which prevents the excavated sides of a trench from collapse and which allows personnel to access and work in the trench in a safe and secure environment.

BACKGROUND

The skilled person will appreciate that with most forms of residential, commercial and industrial property construction, the first stages of the work generally involve ground preparation and levelling of the site, prior to excavation of trenches or ditches that ultimately form the foundation footings of the property. Equally, earth excavations can be needed for the installation and repair of pipelines, structures and water, drainage, sewerage, gas and other sub-surface utilities and assets. Work of this nature is usually carried out using heavy construction equipment, such as excavators or diggers and the like.

Depending upon the soil and environmental conditions, there is often the risk of the vertical or near vertical sides of the excavation collapsing into the trench, which not only requires significant rework, introducing associated delays and costs, but more importantly, this presents a danger to construction workers and other personnel working on, or near, the excavation site.

Often construction personnel, installation or repair workers, need to enter the excavated trench to lay, install, repair, or otherwise access utilities or assets being laid in, or exposed within, in the trench. Current UK and European Standards specify the criteria in which a trench shoring system is required to protect workers in a trench from a cave-in or collapse. There are various proprietary trench boxes available in the art which generally comprise side walls of varying thicknesses and which are held apart by steel or aluminium props, jacks or spreaders. Commercial trench boxes of this type are time consuming to install, and crucially often require the construction or utilities worker to enter the trench to construct the trench box, with the associated risk of death or injury from a cave-in or collapse. In addition to commercial trench boxes, workers sometimes construct ad hoc structures, made up of boarding to contact the excavated side of the trench and utilise what is to hand that can act as a prop or jack.

The present applicant has developed various trench and excavation shoring systems which enable installation and removal to be completed rapidly. Compared to known proprietary trench boxes and the like, such ready-to-deploy shoring systems, marketed under the brand name DOTS™ and FUTS™, save significant amounts of time and money, and are disclosed in WO 2020/115460 Al.

There is also a strong need for a trench shoring apparatus that, when deployed in the excavated trench, can be locked or secured in place and which is able to resist any lateral force from the excavated sides of the trench, and which also allows construction and/or utilities personnel to safely enter the trench to carry out repairs or installation work. ShoreTrench™ also market a PATS™ unit which includes a fail-safe lock mechanism to provide workforce protection from trench collapse, as described in WO 2021/009479 Al.

Whilst the PATS™ unit minimises the need for a worker to enter, reach or lean into the trench, it does not entirely do away with the need for the worker to approach the trench during deployment. Therefore, there is a strong commercial need for a trench shoring apparatus that can be manoeuvred in position using a mechanical excavator or digger and deployed into the trench and extended using hydraulic power. In this way, the trench shoring apparatus can be deployed without the operator even leaving the cab. There is also a strong commercial need for a trench shoring apparatus that can be utilised with a wide variety of trenches, excavations and worksites, and which provides a largely unhindered interior space for subsequent installation and repair works of underground pipes, cables, ducting and utilities in, or near, pavements, highways, railways and the like. It is an object of the present invention to provide a hydraulically operable trench shoring apparatus that can be rapidly and easily deployed to provide a temporary earth retaining structure which prevents the excavated sides of trenches or ditches from cave-in or collapse. The transport and deployment of the trench shoring apparatus being entirely accomplished from the operator’s cab of a mechanical excavator or digger, and crucially above the surface of the trench. It is a further object of the present invention to provide a trench shoring apparatus that can be deployed autonomously in a wide variety of trench widths and heights, and which utilises a hydraulic actuator to take up, and shore, the space between the side walls of the trench. It is a further object of the present invention to provide a hydraulically operable trench shoring apparatus that utilises a hydraulic failsafe configuration such that, when deployed, it can resist any lateral force from the excavated sides of trenches or ditches and which allows construction and/or utilities personnel to safely enter the trench to carry out repairs or installation work. The present invention maximises the interior space within the deployed shoring apparatus to provide largely unhindered access for installation and/or remedial works of underground pipes, cables, ducting and utilities in pavements and highways, railways and the like. It is a further object of the present invention to provide a trench shoring apparatus that can be quickly and autonomously retrieved from the trench after use, again without the need for an operator to enter, reach or lean into the trench or excavation.

SUMMARY OF THE INVENTION

The present invention is described herein and in the claims.

According to the present invention there is provided a trench shoring apparatus, comprising: first and second side panels having a top edge, a bottom edge and side edges, the first and second side panels being connected in a parallel spaced-apart configuration by a transverse strut being mounted proximate each side edge thereof and nearer the top edge than the bottom edge; and actuator means being operable to vary the length of the transverse strut from a first length to a second length.

The advantage of the present invention is that it can be invention is that it can be used to rapidly and securely provide an adjustable temporary earth-retaining structure which prevents the excavated sides of a trench from cave-in or collapse from the operator’s cab of heavy construction equipment, such as excavators or diggers and the like. The present invention maximises the interior space within the deployed shoring apparatus to enable largely unhindered access for construction and/or utilities personnel.

Preferably, the apparatus being formed as a rectangle or square shape.

Further preferably, the first and second side panels having a castellated cross section and each having an inner and outer surface, and wherein the outer surfaces of the first and second side panels abut the excavated sides of the trench when in use, and wherein the inner surfaces of the first and second side panels are each connected to the transverse strut.

In use, the transverse strut may be secured to the inner surfaces of the first and second side panels via a seam of welding.

Preferably, the first length of the transverse strut corresponds to a retracted configuration that has a lateral dimension which is less than the width of the trench into which the apparatus is inserted when in use and which is less than the width of the second length of the transverse strut which corresponds to an extended configuration.

Further preferably, prior to installing the apparatus in the trench the actuator means being operable to position the transverse strut to the first length whereby the apparatus can be placed between the excavated sides of the trench.

In use, the actuator means may be operable to position the transverse strut to the second length whereby the outer surfaces of the first and second side panels abut against the excavated sides of the trench to deploy the apparatus, the actuator means being in a rigid condition whilst the apparatus is deployed in the trench.

Preferably, the actuator means further comprises a cylinder and piston capable of being pumped with a fluid which also includes a check valve to lock the strut in the rigid condition. Further preferably, the fluid is a hydraulic fluid.

In use, the fluid may be pumped from a hydraulic system comprising a self-contained closed-circuit system located on a vehicle selected from the group consisting, but not limited to, any of the following: excavators and diggers, forklift trucks or other wheeled or tracked powered industrial equipment, such as, backhoe-loaders and the like.

Preferably, the transverse strut further comprises first and second strut arms being mounted generally from the top edge to the bottom edge of each of the side panels.

Further preferably, the first strut arm comprises a generally flat first face and an opposite second face having a series of structural ribs extending from the first face to the second face; and the second strut arm comprises a generally flat first face and an opposite second face having a series of structural ribs extending from the first face to the second face, the first strut arm and second strut arm being inverted L-shaped in plan view from the side.

In use, the first strut arm may comprise a female receiving portion disposed between the first and second faces.

Preferably, a male engagement portion is disposed on the second strut arm which can, in a translational manner, be slidably received in, and out of, the female receiving portion.

Further preferably, the second strut arm defines a ledge which is positioned generally underneath the male engagement portion.

In use, the apparatus may further comprise: a gap being positioned between a lower face of the male engagement portion and an upper face of the ledge; a plurality of upwardly-facing linear sliding bearings being positioned on an upper surface of the male engagement portion; a plurality of downwardly-facing linear sliding bearings being positioned on a lower surface of the male engagement portion; and a linear sliding bearing is positioned on the upper face of the ledge. Preferably, the male engagement portion and female receiving portion are both formed from lengths of rectangular box section mild steel, but being dimensioned such that there is a clearance fit between the male engagement portion and the female receiving portion and which enables the two parts to be slidably connected via the linear sliding bearings.

Further preferably, any twisting and rotational forces are resisted in use as the second strut arm has a smaller thickness between the first and second faces thereof and is slidably received between the first and second faces of the first strut arm.

In use, the apparatus may further comprise a removable hoisting beam which is elongate and connects with a lug that extends from the upper surface of each first strut arm, the hoisting beam having one or more hoisting hitches disposed thereon such that the hoisting beam releasably connects to the apparatus and can be used to raise or lower the apparatus, the hoisting beam also hydraulically connects the actuator means to the hydraulic system disposed on the vehicle.

Preferably, the apparatus further comprising a series of steps or rungs disposed on the inner surface of the castellated side panels, the rungs being configured to form an internal ladder which provide access to the deployed trench shoring apparatus.

Further preferably, the apparatus further comprising a retractable or mountable guardrail and/or edge restraint disposed at the inner surface of the side panels and which is erectable to provide edge protection to prevent falls into the deployed trench shoring apparatus.

In use, the trench shoring apparatus may further comprise a mechanical fail-safe locking mechanism that is positioned between the first and second strut arms.

Preferably, the mechanical fail-safe locking mechanism comprises a ratchet mechanism comprising: a linear rack of teeth mounted on one of the strut arms; a spring-loaded pawl being mounted on the other one of the strut arms and having a proximal end centred about a first pivot point and a second pivot point, and a distal end capable of engagement with the teeth on the rack.

Further preferably, the second pivot point is coupled to a hydraulic ram which can move in a slideable back-and-forth manner to raise the distal end of the pawl clear of the teeth on the rack in a normal operating condition.

Preferably, in a fail-safe condition caused by a loss or damage to the hydraulic check valve and/or pressurised hydraulic system, the pawl being urged by spring-bias about the first pivot point to cause engagement of the distal end of the pawl against a stop on one of the teeth of the rack to limit retraction of the side panels.

In use, the apparatus may further comprise a ground mat which abuts against the first and/or second side panels for improved aboveground trafficking and access when in use.

Preferably, the metalwork components forming the apparatus are selected from a material from the group consisting, but not limited to, any one of the following: mild, powder-coated or galvanised steel, or aluminium and the like.

Further preferably, the linear sliding bearings, ground mat and/or parts thereof may be manufactured a suitable plastics or rubberised material selected from the group consisting, but not limited to, any of the following: Polypropylene (PP), Low-Density Polyethylene (LDPE), High-Density Polyethylene (HDPE), Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC) or Acrylonitrile Butadiene Styrene (ABS), Glass Reinforced Nylon (GRN), resins or blends thereof.

Also according to the present invention there is provided a method of supporting the side walls of an excavated trench using the trench shoring apparatus as hereinbefore described, the method comprising the steps of: coupling a removable beam to the trench shoring apparatus; connecting the removable beam to a hydraulic supply and retracting the transverse strut to the retracted spaced-apart configuration; hoisting the retracted apparatus into the excavated trench; extending the transverse strut such that the side panels splay apart into the extended spaced-apart configuration to abut against the side walls of the excavated trench; and uncoupling the removable beam from the trench shoring apparatus and hoisting it clear of the extended apparatus.

Further according to the present invention there is provided a cradle for receiving, transporting and/or stowing a trench shoring apparatus, comprising: a frame part which has four vertical posts arranged from the frame part and spaced apart from each other at predetermined intervals to form a rectangular frame and an upper end frame connecting to upper end parts of the four vertical posts and into which a trench shoring apparatus can be received, the frame part having provision for mounted accessories, and coupling means for connecting the cradle to a transporting vehicle.

Likewise according to the present invention there is provided an apparatus for shoring a trench, comprising: first and second side panels having a top edge, a bottom edge and side edges, the first and second side panels being connected in a parallel spaced-apart configuration by a transverse strut being mounted proximate each side edge thereof and nearer the top edge than the bottom edge; actuator means being operable to vary the length of the transverse strut from a first length to a second length; and a hoisting beam which is hydraulically connectable to the actuator means and having coupling means connectable for quick-hitch or the like coupling to an articulated working arm of an excavator, digger or other vehicle supplying hydraulic power.

Preferably, the coupling means comprises: a first quick hitch coupler disposed on the beam for hitching the hoisting beam to the working arm of an excavator, digger or other vehicle supplying hydraulic power; and a second quick hitch coupler disposed on the beam for hitching the hoisting beam to the actuator means. It is believed that a hydraulically operable trench shoring apparatus and its method of use in accordance with the present invention at least addresses the problems outlined above.

It will be obvious to those skilled in the art that variations of the present invention are possible and it is intended that the present invention may be used other than as specifically described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example only, and with reference to the accompanying drawings, in which:

Figure l is a perspective view from the side and above of a hydraulically operable trench shoring apparatus in accordance with the present invention in a retracted configuration;

Figure 2 illustrates a side plan view of the hydraulically operable trench shoring apparatus of Figure 1;

Figure 3 shows a perspective view from the side and above of the hydraulically operable trench shoring apparatus in accordance with the present invention being in an extended configuration;

Figure 4 is a side plan view of the hydraulically operable trench shoring apparatus of Figure 3;

Figure 5 illustrates a perspective view from the side and above of the hydraulically operable trench shoring apparatus in accordance with the present invention being disassembled;

Figure 6 shows a side plan view of the disassembled hydraulically operable trench shoring apparatus of Figure 5;

Figure 7 is a cutaway perspective view from the side and above of the interior of the disassembled hydraulically operable trench shoring apparatus of Figure 5 and showing further detail of the strut positioned between the side walls; Figure 8 illustrates a perspective view from the side and above of the hydraulically operable trench shoring apparatus in accordance with the present invention with a detachable hoisting beam attached;

Figure 9 shows a perspective view from the side and above of the hydraulically operable trench shoring apparatus of Figure 8 with the detachable hoisting beam detached;

Figure 10 is a perspective view from the side and above of the strut arms of a hydraulically operable trench shoring apparatus in accordance with a second embodiment of the invention, and which includes a mechanical fail-safe locking mechanism;

Figure 11 illustrates a perspective view from the side and above of a cradle that can receive, transport and stow any of the trench shoring apparatuses described herein;

Figure 12 shows a perspective view from the side and above of a mountable edge restraint that can be used with any of the trench shoring apparatuses described herein to prevent inadvertent personnel access at the open ends of the deployed trench shoring apparatus; and

Figure 13 is a principally schematic view showing the hydraulic system of the trench shoring apparatus of the present invention and its interconnection with the hydraulic system provided on a mechanical excavator or digger.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention has adopted the approach of utilising a hydraulically operable trench shoring apparatus that can be rapidly and easily deployed to provide a temporary earth retaining structure which prevents the excavated sides of trenches or ditches from cave-in or collapse. The transport and deployment of the trench shoring apparatus being entirely accomplished from the operator’s cab of a mechanical excavator or digger, and crucially above the surface of the trench. Advantageously, the present invention provides a trench shoring apparatus that can be deployed autonomously in a wide variety of trench widths and heights, and which utilises a hydraulic actuator to take up, and shore, the space between the side walls of the trench. Further advantageously, the present invention also provides a hydraulically operable trench shoring apparatus that utilises a hydraulic fail-safe configuration such that, when deployed, it can resist any lateral force from the excavated sides of trenches or ditches and which allows construction and/or utilities personnel to safely enter the trench to carry out repairs or installation work. The present invention maximises the interior space within the deployed shoring apparatus to provide largely unhindered access for installation and/or remedial works of underground pipes, cables, ducting and utilities in pavements and highways, railways and the like. Further advantageously, the present invention also provides a trench shoring apparatus that can be quickly and autonomously retrieved from the trench after use, again without the need for an operator to enter, reach or lean into the trench or excavation.

Referring now to the drawings, a hydraulically operable trench shoring apparatus 10 according to the present invention is illustrated in Figures 1 to 7.

The hydraulically operable trench shoring apparatus 10 is formed having first and second panels 12a, 12b held in a parallel spaced-apart configuration. In a preferred embodiment, the panels 12a, 12b are formed from sheet piles 14 which include a castellated cross section 16 and generally horizontal seams 18 being arranged to interlock the separate sheets of piling 14 together. In a preferred embodiment, the interconnection between the separate piling sheets 14 is by spot-welds and the like. The skilled person will appreciate that when the apparatus 10 is deployed in a trench (not shown), it is the outer surface of the panels 12a, 12b that are in contact with the excavated sides of the trench to prevent a cave-in or collapse. Whilst in a preferred embodiment of the invention, the first and second panels 12a, 12b are formed from castellated piling sheets 14, the skilled person will appreciate that any number of structurally durable panels, including planar panels, could be utilised.

The first and second side panels 12a, 12b are connected in a parallel spaced-apart configuration and the spaced-apart panels 12a, 12b are able to move between extended and retracted spaced-apart parallel configurations when being deployed in, or retrieved from, a trench (not shown). It will be appreciated that within this application, the term “extended configuration” means a deployed or spaced-apart parallel configuration of the side panels 12a, 12b in which the outer surfaces of the side panels 12a, 12b abut against the side walls of the excavated trench (e.g., Figure 3). The term “retracted configuration” means a reduced spaced-apart lateral configuration or dimension between the side panels 12a, 12b. The retracted configuration has a spaced-apart dimension which is less than the extended configuration, and critically less than the width of the trench into which the apparatus 10 is to be deployed (e.g., Figure 1). Movement of the side panels 12a, 12b between retracted and extended spaced-apart configurations is via a hydraulic actuator mechanism, as described below.

First and second strut arms 20a, 20b are mounted generally from the top to the bottom of each of the side panels 12a 12b and situated towards each end thereof, as best shown in Figures 5 and 6. Each of the strut arms 20a, 20b being secured to, an extending from, the inner surface of the panels 12a, 12b through a seam of welding. Equally, the skilled person will appreciate that any number of mechanical fixings could be utilised.

The first strut arm 20a is disposed on the inner surface of the first side panel 12a and having a slightly different, but complementary, shape to the second strut arm 20b disposed on the inner surface of the second side panel 12b, as perhaps best shown in Figure 6.

The first and second strut arms 20a, 20b allow translational movement of the of the side panels 12a, 12b between retracted and extended spaced-apart configurations, and have a generally inverted L-shaped cross section in plan view from the side, as best shown in Figure 6. The first strut arm 20a being formed having a generally flat first face 22 and an opposite second face 24. A series of structural ribs extend from the first face 22 to the second face 24 which are not shown in the drawings for reasons of clarity. The first and second faces 22, 24 and ribs in combination define a first strut arm 20a onto which the other components of the hydraulic actuator mechanism are affixed.

The second strut arm 20b being formed having a generally flat first face 26 and an opposite second face 28. A series of structural ribs extend from the first face 26 to the second face 28 which are not shown in the drawings for reasons of clarity. The first and second faces 26, 28 and ribs in combination define a second strut arm 20b onto which the other components of the hydraulic actuator mechanism are affixed. Interposed between the first and second faces 22, 24 of the first strut arm 20a is a female receiving portion 30. In a preferred embodiment of the invention, the female receiving portion 30 is formed as an open length of rectangular box section mild steel, as best shown in Figure 7.

Disposed on the opposite second sturt arm 20b is a male engagement portion 32 which can, in a translational manner, be slidably received in, and out of, the female receiving portion 30. Again, the male portion 32 is formed as a length of rectangular box section mild steel, but being dimensioned such that there is a clearance fit between it and the female receiving portion 30 and which enables the two parts to be slidably connected.

The first and second faces 26, 28 on the second strut arm 20b also define a ledge 34 which is generally underneath the male portion 32. A gap 36 is positioned between the bottom face of the male portion 32 and the top of ledge 34, as best shown in Figures 6 and 7. A plurality of upwardly-facing linear sliding bearings 38a, 38b, 38c are positioned on an upper surface 40 of the male portion 32. A plurality of downwardly-facing linear sliding bearings 42a, 42b, 42c are positioned on a lower surface 44 of the male portion 32. A sliding bearing 46 is also positioned on an upper surface 48 of the ledge 34.

The skilled person will understand that the upwardly-facing linear sliding bearings 38a, 38b, 38c can instead be replaced by a single strip of linear sliding bearing material (not shown). In a further embodiment of the invention, the plurality of downwardly-facing linear sliding bearings 42a, 42b, 42c which are positioned on a lower surface 44 of the male portion 32 can be entirely omitted.

An internal cutaway section 50 is formed in first and second faces 22, 24 of the first strut arm 20a. This is to increase the line of welding which secures the female receiving portion 30 between the first and second faces 22, 24 of the first strut arm 20a, and thereby increase the mechanical strength thereof.

The first and second strut arms 20a, 20b are mounted proximate to one open end 70 of the side panels 12a, 12b, and another first and second strut arms 20a, 20b are mounted proximate the other open end 72 of the side panels 12a, 12b. The first and second strut arms 20a, 20b being capable of translational movement therebetween such that side panels 12a, 12b can move between retracted and extended spaced-apart configurations. In view of the significant translational and twisting forces that are exhibited on the side panels 12a, 12b, the skilled person will appreciate that the gap 36 formed between the plurality of downwardly-facing linear sliding bearings 42a, 42b, 42c positioned on a lower surface 44 of the male portion 32 and the sliding bearing 46 formed on the ledge 34, and the upwardly-facing linear sliding bearings 38a, 38b, are positioned on an upper surface 40 of the male portion 32 enables the significant mass of the apparatus 10 to be moved in a linear manner. Any twisting and rotational forces are resisted since the second strut arm 20b, having a smaller thickness between the first and second faces 26, 28, is slidably received between the first and second faces 22, 24 of first strut arm 20a. The shape, and the interconnection, of the first and second strut arms 20a, 20b spreads the significant forces that are exhibited on the side panels 12a, 12b and only one pair of first and second strut arms 20a, 20b are needed proximate the top of the side panels 12a, 12b and adjacent both open ends 70, 72. This enables an accessible, low profile trench shoring apparatus 10 to be deployed, providing plenty of internal space for personnel to work.

In such a configuration, the male engagement portion 32 is slidably received in, and out of, the female receiving portion 30 in a generally horizontal configuration and cannot be moved despite any lateral force applied to the side panels 12a, 12b, and therefore in conjunction with a hydraulic actuator mechanism, the apparatus 10 can act as an adjustable temporary earth-retaining structure which prevents the excavated sides of a trench from cave-in or collapse.

In shoring apparatus 10, the male engagement portion 32 and complementary female receiving portion 30 are positioned as a pair adjacent to the open ends 70, 72 of the side panels 12a, 12b and mounted proximate the top of the side panels 12a, 12b to enable largely unhindered access by construction and/or utilities personnel installation working in the shored trench.

The actuation of the first and second strut arms 20a, 20b is via a hydraulic actuator mechanism, that is depicted some schematically in Figures 1 to 4. A hydraulic ram 52 is located between the side panels 12a, 12b. In the embodiment shown in Figures 1 to 4, the barrel 54 of the ram 52 is connected to a connection point 56 on the first strut arm 20a, and a movable piston 58 of the ram 52 connected to a connection point 60 on the second strut arm 20b. This is in no way intended to be limiting as the position of the barrel 54 or piston 58 can of course be reversed without affecting the functionality thereof

The skilled person will understand that hydraulic actuation of the ram 52 causes translational movement of the side panels 12a, 12b. The hydraulic actuator mechanism as described herein also include various other features that are not shown in the drawings but are implicitly described, including a check valve. The check valve provides an inherent fail-safe locking mechanism when the hydraulic power is detached intentionally or even inadvertently. Since hydraulic fluids do not compress, this is beneficial to control, and because the fluid in a hydraulic actuator 52 cannot be compressed this provides rigidity when the liquid is not flowing, and precision control when it is.

The hydraulic systems described herein are self-contained closed-circuit systems that are present on many excavators and diggers, and forklift trucks or other wheeled or tracked powered industrial equipment, such as, backhoe-loaders and the like. The hydraulic connections or couplers which supply to the actuator ram 52 are therefore mounted on, and controlled from, the excavator or digger. This hydraulic interconnection is described further in relation to Figures 8 and 9.

The struts 20a, 20b are elongate bars disposed towards the upper section of the apparatus 10. The skilled person will appreciate that when deployed, the hydraulically operable trench shoring apparatus 10 comprises a rectangular-shaped structure, the side panels 12a, 12b of which can be used to contact or abut against the excavated sides of trenches or ditches to prevent cave-ins or collapse. The hydraulic actuation of the ram 52 causes movement of the piston 58 relative to the barrel 54 and which causes the spaced-apart panels 12a, 12b to move between an extended parallel spaced-apart configuration for deployment in a trench, and a retracted parallel spaced-apart configuration for insertion into the trench.

The fail-safe check valve acts automatically to restrict any movement of the ram 52 relative to the side panels 12a, 12b such that when the apparatus 10 is deployed, the side panels 12a, 12b of the apparatus 10 cannot be moved despite any lateral force applied thereto. Figure 10 shows a second embodiment of the trench shoring apparatus 10. The construction of the second embodiment is very similar to that of the first embodiment and corresponding features have been given the same reference numerals. The second embodiment differs from the first embodiment in that over-and-above the fail-safe hydraulic check valve which acts automatically to restrict any movement of the ram 52, the apparatus 10 can further be provided with a supplementary mechanical fail-safe locking mechanism which restricts inward translational movement of the first and second side panels 12a, 12b to further ensure workforce protection when working in the trench.

In this embodiment of the invention, the mechanical fail-safe locking mechanism is provided as a ratchet mechanism 74 that is located between the first and second strut arms 20a, 20b. Such a ratchet mechanism 74 is a mechanical fail-safe device that allows continuous linear motion in only one direction (allowing outward movement of the spaced-apart panels 12a, 12b to an extended spaced-apart configuration) while preventing motion in the opposite direction (resists a compressive force inwards on the outer surfaces of the side panels 12a, 12b). It is worth restating at this juncture that the ratchet mechanism 74 is a supplementary mechanical fail-safe device that would be called upon as a fail-safe design feature should there be any catastrophic failure to the hydraulic check valve and/or pressurised hydraulic system.

The ratchet mechanism 74 consists of a linear rack 76 of teeth 78. In a preferred embodiment, the rack 76 being affixed to the upper surface 40 of the male engagement portion 32. In the illustrative embodiment shown in Figure 10, there are six teeth 78a, 78b, 78c, 78d, 78e, 78f which are each identical. The skilled person will understand that the number of teeth 78 disposed on the linear rack 76 is in no way intended to be limiting.

Each tooth 78 is asymmetrical having a slope 80 on a first edge and a stop 82 on the opposite second edge. In Figure 10, the slope 80 is illustrated on tooth 78d and the stop 82 illustrated on tooth 78f.

The ratchet mechanism 74 also comprises a pivoting, spring-loaded pawl 84 that engages the teeth 78. The pawl 84 being pivotally connected between a U-shaped mount or clevis 86 positioned on the upper surface of the first strut arm 20a such that the pawl 84 is able to pivot about a first pivot point 88 in the clevis 86. The distal end 90 of the pawl 80 engages with the teeth 78, as described below.

When the teeth 78 are moving in the unrestricted (i.e., outward or extending) direction, the pawl 84 slides up, and over, the sloped 80 edges of the teeth 78, with a spring (not shown) forcing it (with an audible “clank”) into the depression 92 between the teeth 78 as it passes the tip of each tooth 78. When the teeth 78 move in the opposite (i.e., inward or retracting) direction however, the pawl 84 will catch against the stop edge 82 of the first tooth 78 it encounters, thereby locking it against the tooth 78 and preventing any further motion in that inward direction.

In operation, when it is desired to extend the hydraulic ram 52 to move the spaced-apart side panels 12a, 12b apart into the extended configuration such that they abut against the side walls of the excavated trench, a separate hydraulic ram or actuator 94 is utilised which raises the pawl 84 clear of the teeth 78 on the rack 76. In particular, a movable piston 96 of the ram 94 connects to a second pivot point 98 on the pawl 84. In a preferred embodiment of the invention, the second pivot point 98 is directly above the first pivot point 88. In this way, with the distal end 90 of the pawl 84 raised clear of the teeth 78 on the rack 76, the male engagement portion 32 can be freely slidably received in, and out of, the female receiving portion 30. In the very unlikely event that there is some catastrophic loss or damage to the hydraulic check valve and/or pressurised hydraulic system when the apparatus 10 is deployed in the trench, the skilled person will understand that the ratchet mechanism 74 acts automatically to limit the retraction of the side panels 12a, 12b by engagement of the distal end 90 of the spring-loaded pawl 84 against a stop 82 on one of the teeth 78.

In use, the hydraulically operable trench shoring apparatus 10 is hoisted into the excavated trench using a mechanical excavator or digger (not shown) and a hoisting beam 62. The hoisting beam 62 is elongate and connects with a lug 64 that extends from the upper surface of each first strut arm 20a. At one or both ends of the hoisting beam 62 is a retractable pin 66 which can be slidably received inside an aperture 68 disposed in the lug 64. The actuation of the pin 66 can be under the control of the operator in the excavator or digger. The hoisting beam 62 is itself formed from a length of box-section steel and having one or more hoisting loops (not shown) formed at each end thereof which releasably connects a sling arrangement (not shown) that can be connected to the arm of a mechanical excavator or digger and the like. The hoisting beam 62 serves not only as a slinging aid but also receives and connects to hydraulic couplings disposed on the excavator or digger.

Further detail of how the hoisting beam 62 automatically receives and connects to hydraulic couplings disposed on the excavator or digger (not shown) is illustrated in Figure 13. As described herein, one of the advantages of the present invention is that the hoisted apparatus 10 can be lowered into the trench, and the hydraulic ram 52 extended to shore the trench, all under the control of a button or joystick 128 in the cab of the excavator or digger. The trench shoring apparatus 10 can therefore be deployed in the trench without any worker needing to enter the trench or lean into it, which is a much safer and quicker means of providing temporary trench support.

Figure 13 shows detail of the hydraulic system of the present invention and which makes use of the closed-circuit hydraulic systems that are present on many excavators and diggers, and forklift trucks or other wheeled or tracked powered industrial equipment, such as, backhoe-loaders and the like. Such a closed-circuit hydraulic system, being present on the excavator or digger, generally comprises a hydraulic reservoir 130 from which hydraulic fluid can be pulled through line 158 and pressurised using a pump 132. Some of the fluid is pumped from the reservoir 130 into the metal piping and/or flexible lines 134 running along hoisting beam 62 to a first part of a quick hitch valve block 136 disposed on the boom-end of the excavator or digger. A line return 138 to the reservoir 130 is also coupled to the first part of the quick hitch valve block 136.

The first part of the quick hitch valve block 136 provides a working end with fast couplings 140a, 140b, 140c that connect to complementary ports 140a', 140b', 140c' in a second part of the quick hitch valve block 142 that is situated on the lifting beam 62.

The cab joystick 128 utilises sensors and electronics to receive operator inputs to control the passage of hydraulic fluid through the first 136 and second parts of the quick hitch valve block 142, as would be known by the skilled person in modern hydraulic control systems.

The port 140a' on the second part of the quick hitch valve block 142 provides a first hydraulic line 144 which is connected to lifting beam rams 146 disposed at each end of the lifting beam 62. The lifting beam rams 146 are operable to extend and retract the pin 66 which can be slidably received inside the aperture 68 disposed in the lug 64 that extends from the upper surface of each first strut arm 20a, 20a' as best shown in Figures 8 and 9. In the extended configuration, the pin 66 is receivable in the aperture 68 and the beam 62 is hydraulically and physically connected to the trench shoring apparatus 10. In the retracted configuration, the pin 66 is retracted into the ram 146 distal from aperture 68, and the beam 62 is hydraulically and physically disconnected from the trench shoring apparatus 10.

The port 140b' on the second part of the quick hitch valve block 142 provides a second hydraulic line 148 which is connected to open (extend) the actuator rams 52, 52' disposed at each end of the apparatus 10 between the side panels 12a, 12b.

The port 140c' on the second part of the quick hitch valve block 142 provides a third hydraulic line 150 which is connected to close (retract) the actuator rams 52, 52' disposed at each end of the apparatus 10 between the side panels 12a, 12b.

The second 148 and third hydraulic lines 150 are also connected to a secondary valve block connector having a first part of a quick hitch valve block 152 disposed on the beam 62.

The first part of the quick hitch valve block 152 is mounted on the beam 62 and provides a working end with fast couplings 154a, 154b that connect to complementary ports 154a', 154b' in a second part of the quick hitch valve block 156 that is situated on the apparatus 10. When the first 152 and second parts of the quick hitch valve block 156 are brought together when the lifting beam ram 146 actuates to lock each end of the beam 62 to each first strut arm 20a, 20a', the apparatus 10 becomes pressurised with hydraulic fluid. The port 154a' on the second part of the secondary valve block 156 is connected to a second hydraulic line 148' which is operable to open (extend) the actuator rams 52, 52' disposed at each end of the apparatus 10 between the side panels 12a, 12b.

The port 154b' on the second part of the quick hitch valve block 156 is connected to a third hydraulic line 150' which is operable to close (retract) the actuator rams 52, 52' disposed at each end of the apparatus 10 between the side panels 12a, 12b. When it is desired to retract the ram 52 under the control of the joystick 128, the third hydraulic line 150, 150' is pressurised, and which also pressurises the hydraulic ram or lock 94 to raise the pawl 84 clear of the teeth 78 on the rack 76, as described above in relation to Figure 10.

In use, the hydraulic lines 144, 148, 148', 150, 150' may be protectively channelled through the framework of the beam 62 or the apparatus 10.

Referring again to Figures 1 to 9, the use of the apparatus 10 will now be described in relation to the deployment of a hydraulically operable trench shoring apparatus to act as a temporary earth-retaining structure to prevent the excavated sides of a trench from cavein or collapse.

Typically, an open trench or ditch is excavated using an excavator, as mentioned above. Depending primarily upon the soil substrate and the weather conditions this open trench is at a risk of collapse or cave-in. To shore the trench, the trench shoring apparatus 10 of the present invention can be utilised, which enables a much quicker and secure shoring to be carried out by construction or utilities workers without the need to enter, lean or reach into the excavated trench.

To shore the excavated trench, the operator of the excavator connects a length of chain or other flexible sling (not shown) onto the hoisting loop to position the apparatus 10 in the trench. The length of chain is then connected or wrapped around the bucket or dipper arm such that the trench shoring apparatus 10 can be hoisted clear of the ground.

The operator of the excavator also connects one or more hydraulic hoses to hydraulic couplers disposed on the excavator which provides high-pressure hydraulic fluid to the actuator ram 52, via the hoisting beam 62. The spaced-apart panels 12a, 12b are moved to a retracted spaced-apart configuration whereby the apparatus 10 can be inserted in a trench. Alternatively, the hoisting beam 62 can be connected to a first part of a quick hitch valve block 136 disposed on the boom-end of the excavator or digger, as described above in relation to Figure 13 in order to automatically connect to hydraulic system disposed on the excavator.

The hoisted apparatus 10 can then be lowered into the trench and a button pressed in the cab be operable to extend the hydraulic ram 52 which moves the spaced-apart side panels 12a, 12b apart into the extended configuration such that they abut against the side walls of the excavated trench. In this way, the deployed apparatus 10 acts to shore the trench without needing to enter the trench or lean into it, which is a much safer and quicker means of providing temporary support.

In this configuration, the beam 62 situated at the top of the trench shoring apparatus 10 can then be removed by retracting one or both pins 66, and lifting the beam 62 clear. Removing the beam 62, also manually or automatically disconnects the hydraulic fluid supply to the apparatus 10 and the fluid in a hydraulic actuator 52 cannot then be compressed because of the check valve, and the apparatus 10 is thereby locked in place and is able to resist any lateral force from the excavated sides of the trench.

Personnel can now safely enter the apparatus 10 shoring the trench to carry out repairs or installation work in the trench with largely unhindered access.

When it is needed to remove the trenching shoring apparatus 10, the above method is followed in reverse.

The advantage of the hydraulically operable trench shoring apparatus 10 of the present invention it is it can be simply hoisted into the excavated trench and quickly deployed in place, and thus resisting all lateral force from the sides of the trench or ditch with the deployment and subsequent retrieval of the trench shoring apparatus being at all times from above the surface of the trench, from the operator’s cab of heavy construction equipment, such as excavators or diggers and the like. When the beam 62 is removed, construction and/or utilities personnel can easily and safely enter the apparatus 10 to carry out repairs or installation work in the trench with largely unhindered access. Using a hydraulic actuator mechanism, as described herein, enables much larger trenches or excavations to be shored. The skilled person will also appreciate that the advantage of the hydraulically operable trench shoring apparatus 10 is that the lateral dimension of the apparatus 10 can be altered to suit the different trench widths.

The hydraulically operable trench shoring apparatus 10 of the present invention can also include complementary-shaped male and female interlocking portions (not shown) mounted proximate the top, and correspondingly, the bottom of the side panels 12a, 12b and/or struts 20a, 20b to provide a trench shoring apparatus 10 that can be vertically- stacked one on top of another. The trench shoring apparatus 10 can also be horizontally- arranged in a trench such that it abuts against a neighbouring apparatus 10 so that the interior spaces or passages are aligned to form a continuous string of deployed trench protection.

The skilled person will appreciate that the hydraulically operable trench shoring apparatus 10 is therefore entirely modular in nature and which provides a trench shoring apparatus 10 that is assemblable to provide a longer, deeper and wider adjustable trench protection system when in use.

The metalwork components forming the apparatus 10 can be mild, powder-coated or galvanised steel, or aluminium and the like. The metalwork components forming the apparatus 10 and the hoisting beam 62 can additionally be brightly coloured, or having a hot dip galvanised finish. In a preferred embodiment, the strut arms 20a, 20b are formed from 10mm mild steel plate. This is in no way intended to be limited as the plate thickness can be scaled appropriately to suit different sizes of apparatus 10.

The construction of the apparatus 10 and the hoisting beam 62, or parts thereof, can be via any suitable form of metal fabrication, e.g., from a welded and bolted construction. Equally, the apparatus 10, or parts thereof, can be machined, pressed, cast or forged from a suitable metal.

In use, the retracted and extended configurations of the present invention enable use with trench widths of between around 1.2m to around 1.8m. When the trench shoring apparatus 10 is deployed at the widest extended configuration, the distance between the outer surfaces of the side panels 12a, 12b is around 1.8m, and the distance between the inner surfaces of the side panels 12a, 12b is around 1.65m. The length of side panels 12, 12b can be up to around 3.0m and having a height up to around 2.0m.

The linear sliding bearings 38, 42, 46 may be manufactured from a suitable plastics material selected from the group consisting, but not limited to, any of the following: Polypropylene (PP), Low-Density Polyethylene (LDPE), High-Density Polyethylene (HDPE), Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC) or Acrylonitrile Butadiene Styrene (ABS), Glass Reinforced Nylon (GRN), resins or blends thereof.

Therefore, the hydraulically operable trench shoring apparatus 10 can be used to rapidly and securely provide an adjustable temporary earth-retaining structure which prevents the excavated sides of a trench from cave-in or collapse from the operator’s cab of heavy construction equipment, such as excavators or diggers and the like. The deployed shoring apparatus 10 maximises the interior space therewithin to enable largely unhindered access for construction and/or utilities personnel.

When used in this specification and claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components. The singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes” and/or “including” when used herein, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, separately, or in any combination of such features, can be utilised for realising the invention in diverse forms thereof. The invention is not intended to be limited to the details of the embodiments described herein, which are described by way of example only. It will be understood that features described in relation to any particular embodiment can be featured in combination with other embodiments.

It is contemplated by the inventor that various substitutions, alterations, and modifications may be made to the invention without departing from the spirit and scope of the invention as defined by the claims. Examples of these include the following:

The hydraulically operable trench shoring apparatus 10 of the present invention can be utilised with mountable guardrails to provide edge protection. The skilled person will appreciate that when the trench shoring apparatus 10 has been lowered into the bottom of the excavated trench or ditch, as described above, and the beam 62 removed by lifting it clear, this open-topped trench shoring apparatus 10 would represent a fall hazard. To combat this, a pair of mountable guardrails 100, as shown in a stowed position in Figure 11 can be positioned towards the top of each of the side panels 12a, 12b.

Figure 12 shows that the open ends 70, 72 of the side panels 12a, 12b of a deployed trench shoring apparatus 10 could also represent a fall hazard, when in use. To address this, a pair of mountable edge restraints 102 can be received towards the top of each of the side panels 12a, 12b. Each of the mountable edge restraints 102 being formed from a series of first 104 and second cross members 106 which define or retain a series of meshed panels 108. In a preferred embodiment of the invention, each mountable edge restraint 102 is formed as a central panel 110a interposed between two side panels 110b, 110c. The configuration of panels 110a, 110b, 110c is not a straight line when in a plan view from above, but is instead castellated, as shown in Figure 12.

A section of the trench shoring apparatus 10 can also be provided with a series of internal steps (not shown) to allow a worker to safely descend into, and ascend from, the shored trench.

The trench shoring apparatus 10 can also be provided with ground mats (not shown) which abut against the side panels 12a, 12b for improved aboveground trafficking and access when in use. When deployed with ground mats, vehicular access and trafficking to and from the trench shoring apparatus 10 is improved, especially in wet and muddy ground, and/or the ground mats can prevent the ground from churning up and becoming muddy. In use, the ground mats may be manufactured from a suitable plastics or rubberised material selected from the group consisting, but not limited to, any of the following: Polypropylene (PP), Low-Density Polyethylene (LDPE), High-Density Polyethylene (HDPE), Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC) or Acrylonitrile Butadiene Styrene (ABS), Glass Reinforced Nylon (GRN), resins or blends thereof.

Figure 11 illustrates a perspective view from the side and above of a cradle 112 that can receive, transport and stow any of the trench shoring apparatuses 10 described herein. The cradle 112 comprises a rectangular base section formed from first 114 and second structural members 116. Projecting upwardly from the interconnection of the first 114 and second structural members 116 at each comer thereof is a post 118 that supports rails 120. It is into the rectangular rails 120 that the trench shoring apparatus 10 can be hoisted and stowed, as shown in Figure 11.

In Figure 11, a pair of fork pockets 122 are positioned between the first members 114. The pockets 122 being dimensioned to receive forklift blades or tines (not shown) from forklift trucks or other wheeled or tracked powered industrial equipment, such as, backhoe-loaders and the like. The advantage of providing such fork pockets 122 on the cardie 112 are that the cradle 112 supporting the trench shoring apparatus 10 can be transported and utilised at the worksite more easily, rather than having to rely solely on excavators and diggers.

Also disposed on the cradle 112 are two pairs of sockets 124a, 124b that extend upwardly from the base section. The sockets 124a, 124b each receive one pair of the mountable guardrails 100. Figure 11 shows a mountable guardrail 100 being located inside sockets 124a.

The cradle 112 can also receive the hoisting beam 62, and this is shown in Figure 11 as being retained on hooks 126 disposed on posts 118.

Claims

26 CLAIMS

1. A trench shoring apparatus, comprising: first and second side panels having a top edge, a bottom edge and side edges, the first and second side panels being connected in a parallel spaced-apart configuration by a transverse strut being mounted proximate each side edge thereof and nearer the top edge than the bottom edge; and actuator means being operable to vary the length of the transverse strut from a first length to a second length.

2. The trench shoring apparatus as claimed in claim 1, wherein the apparatus being formed as a rectangle or square shape.

3. The trench shoring apparatus as claimed in claims 1 or 2, wherein the first and second side panels having a castellated cross section and each having an inner and outer surface, and wherein the outer surfaces of the first and second side panels abut the excavated sides of the trench when in use, and wherein the inner surfaces of the first and second side panels are each connected to the transverse strut.

4. The trench shoring apparatus as claimed in claim 3, wherein the transverse strut is secured to the inner surfaces of the first and second side panels via a seam of welding.

5. The trench shoring apparatus as claimed in any of the preceding claims, wherein the first length of the transverse strut corresponds to a retracted configuration that has a lateral dimension which is less than the width of the trench into which the apparatus is inserted when in use and which is less than the width of the second length of the transverse strut which corresponds to an extended configuration.

6. The trench shoring apparatus as claimed in any of the preceding claims, wherein prior to installing the apparatus in the trench the actuator means being operable to position the transverse strut to the first length whereby the apparatus can be placed between the excavated sides of the trench.

7. The trench shoring apparatus as claimed in any of the preceding claims, the actuator means being operable to position the transverse strut to the second length whereby the outer surfaces of the first and second side panels abut against the excavated sides of the trench to deploy the apparatus, the actuator means being in a rigid condition whilst the apparatus is deployed in the trench.

8. The trench shoring apparatus as claimed in claim 7, wherein the actuator means further comprises a cylinder and piston capable of being pumped with a fluid which also includes a check valve to lock the strut in the rigid condition.

9. The trench shoring apparatus as claimed in claim 8, wherein the fluid is a hydraulic fluid.

10. The trench shoring apparatus as claimed in claims 8 or 9, wherein the fluid is pumped from a hydraulic system comprising a self-contained closed-circuit system located on a vehicle selected from the group consisting, but not limited to, any of the following: excavators and diggers, forklift trucks or other wheeled or tracked powered industrial equipment, such as, backhoe-loaders and the like.

11. The trench shoring apparatus as claimed in claim 1, wherein the transverse strut further comprises first and second strut arms being mounted generally from the top edge to the bottom edge of each of the side panels.

12. The trench shoring apparatus as claimed in claim 11, wherein the first strut arm comprises a generally flat first face and an opposite second face having a series of structural ribs extending from the first face to the second face; and the second strut arm comprises a generally flat first face and an opposite second face having a series of structural ribs extending from the first face to the second face, the first strut arm and second strut arm being inverted L-shaped in plan view from the side.

13. The trench shoring apparatus as claimed in claim 12, wherein the first strut arm comprises a female receiving portion disposed between the first and second faces.

14. The trench shoring apparatus as claimed in claims 12 or 13, wherein a male engagement portion is disposed on the second strut arm which can, in a translational manner, be slidably received in, and out of, the female receiving portion.

15. The trench shoring apparatus as claimed in any of claims 12 to 14, wherein the second strut arm defines a ledge which is positioned generally underneath the male engagement portion.

16. The trench shoring apparatus as claimed in claim 15, wherein the apparatus further comprises: a gap being positioned between a lower face of the male engagement portion and an upper face of the ledge; a plurality of upwardly-facing linear sliding bearings being positioned on an upper surface of the male engagement portion; a plurality of downwardly-facing linear sliding bearings being positioned on a lower surface of the male engagement portion; and a linear sliding bearing is positioned on the upper face of the ledge.

17. The trench shoring apparatus as claimed in claim 16, wherein the male engagement portion and female receiving portion are both formed from lengths of rectangular box section mild steel, but being dimensioned such that there is a clearance fit between the male engagement portion and the female receiving portion and which enables the two parts to be slidably connected via the linear sliding bearings.

18. The trench shoring apparatus as claimed in claims 16 or 17, wherein any twisting and rotational forces are resisted in use as the second strut arm has a smaller thickness between the first and second faces thereof and is slidably received between the first and second faces of the first strut arm.

19. The trench shoring apparatus as claimed in claim 10, further comprising a removable hoisting beam which is elongate and connects with a lug that extends from the upper surface of each first strut arm, the hoisting beam having one or more hoisting hitches disposed thereon such that the hoisting beam releasably connects to the apparatus 29 and can be used to raise or lower the apparatus, the hoisting beam also hydraulically connects the actuator means to the hydraulic system disposed on the vehicle.

20. The trench shoring apparatus as claimed in claim 3, further comprising a series of steps or rungs disposed on the inner surface of the castellated side panels, the rungs being configured to form an internal ladder which provide access to the deployed trench shoring apparatus.

21. The trench shoring apparatus as claimed in claim 3, further comprising a retractable or mountable guardrail and/or edge restraint disposed at the inner surface of the side panels and which is erectable to provide edge protection to prevent falls into the deployed trench shoring apparatus.

22. The trench shoring apparatus as claimed in claim 11, further comprising a mechanical fail-safe locking mechanism that is positioned between the first and second strut arms.

23. The trench shoring apparatus as claimed in claim 22, wherein the mechanical failsafe locking mechanism comprises a ratchet mechanism comprising: a linear rack of teeth mounted on one of the strut arms; a spring-loaded pawl being mounted on the other one of the strut arms and having a proximal end centred about a first pivot point and a second pivot point, and a distal end capable of engagement with the teeth on the rack.

24. The trench shoring apparatus as claimed in claim 23, wherein the second pivot point is coupled to a hydraulic ram which can move in a slideable back-and-forth manner to raise the distal end of the pawl clear of the teeth on the rack in a normal operating condition.

25. The trench shoring apparatus as claimed in claim 23, wherein in a fail-safe condition caused by a loss or damage to the hydraulic check valve and/or pressurised hydraulic system, the pawl being urged by spring-bias about the first pivot point to cause engagement of the distal end of the pawl against a stop on one of the teeth of the rack to limit retraction of the side panels. 30

26. The trench shoring apparatus as claimed in any of the preceding claims, further comprising a ground mat which abuts against the first and/or second side panels for improved aboveground trafficking and access when in use.

27. The trench shoring apparatus as claimed in any of the preceding claims, wherein the metalwork components forming the apparatus are selected from a material from the group consisting, but not limited to, any one of the following: mild, powder-coated or galvanised steel, or aluminium and the like.

28. The trench shoring apparatus as claimed in any of the preceding claims, wherein the linear sliding bearings, ground mat and/or parts thereof may be manufactured a suitable plastics or rubberised material selected from the group consisting, but not limited to, any of the following: Polypropylene (PP), Low-Density Polyethylene (LDPE), High-Density Polyethylene (HDPE), Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC) or Acrylonitrile Butadiene Styrene (ABS), Glass Reinforced Nylon (GRN), resins or blends thereof.

29. A method of supporting the side walls of an excavated trench using the trench shoring apparatus as claimed in any of claims 1 to 28, the method comprising the steps of: coupling a removable beam to the trench shoring apparatus; connecting the removable beam to a hydraulic supply and retracting the transverse strut to the retracted spaced-apart configuration; hoisting the retracted apparatus into the excavated trench; extending the transverse strut such that the side panels splay apart into the extended spaced-apart configuration to abut against the side walls of the excavated trench; and uncoupling the removable beam from the trench shoring apparatus and hoisting it clear of the extended apparatus.

30. A cradle for receiving, transporting and/or stowing a trench shoring apparatus, comprising: a frame part which has four vertical posts arranged from the frame part and spaced apart from each other at predetermined intervals to form a rectangular frame and 31 an upper end frame connecting to upper end parts of the four vertical posts and into which a trench shoring apparatus can be received, the frame part having provision for mounted accessories, and coupling means for connecting the cradle to a transporting vehicle.

31. An apparatus for shoring a trench, comprising: first and second side panels having a top edge, a bottom edge and side edges, the first and second side panels being connected in a parallel spaced-apart configuration by a transverse strut being mounted proximate each side edge thereof and nearer the top edge than the bottom edge; actuator means being operable to vary the length of the transverse strut from a first length to a second length; and a hoisting beam which is hydraulically connectable to the actuator means and having coupling means connectable for quick-hitch or the like coupling to an articulated working arm of an excavator, digger or other vehicle supplying hydraulic power.

32. The apparatus as claimed in claim 31, wherein the coupling means comprises: a first quick hitch coupler disposed on the beam for hitching the hoisting beam to the working arm of an excavator, digger or other vehicle supplying hydraulic power; and a second quick hitch coupler disposed on the beam for hitching the hoisting beam to the actuator means.