Device for inserting elongated object into channel

Abstract

A depressor (16) for inserting a cable (4) into a trench (6) is disclosed. The depressor (16) comprises a plurality of cable boots (22) adapted to be mounted to the support (18) and engage the cable (4). The positioning pin substantially prevents movement of the cable shoe (22) relative to the support (18) in the first direction due to movement of the cable shoe (22) relative to the cable (4) in the axial direction of the cable (4). The load cell provides an output dependent on a force applied to the cable shoe (22) in a second direction transverse or perpendicular to the first direction.

Description

[0001] The present disclosure relates to an apparatus for inserting an elongate object into a ditch, and particularly, but not exclusively, to an apparatus for inserting a cable into a ditch in the bottom of a body of water, such as the sea bed.

[0002] The lowering of the cable into the trench formed by a trenching vehicle is achieved either passively (by relying on the cable's own weight) or actively, ie by actively inserting the cable into the trench with the aid of a mechanical arm called a hold-down attached to the trenching vehicle.

[0003] Deadweight lowering has advantages over using active holddowns because there is no physical contact between the cable and the holddown, which therefore reduces the risk of damaging the cable. In particular, the cable is subject to reduced bending during deadweight lowering compared to passing around a holddown where the cable may be forced into an "s" shaped bend which may damage the cable.

[0004] Another advantage of the reduced deadweight is the elimination of radial loads on the cable, which can lead to a significant risk of cable damage. For example, some power cables are sensitive to radial loads, i.e. forces acting perpendicularly to the cable axis. Cable manufacturers usually specify load limits that must not be exceeded during laying and burial. For this reason, the amount of downforce applied by the downforcer to the cable must be quantified and limited. In some cases, the downforcer is used only as a sensor in order to determine the cable position, i.e. the burial depth.

[0005] In contrast, the use of a screw down provides one or more advantages over deadweight lowering. In particular, deadweight lowering may involve an increase in the number of trenching passes required to lower the cable to the desired depth. Each pass will lower the cable a distance depending on the cable weight, cable diameter, soil strength and composition, the effectiveness of the trench being sprayed (to fluidize debris in the trench), cable tension, and trenching speed. Burial depth is more difficult to measure without the screw down contacting the cable. Cable depth can be measured using airborne detection equipment, typically using cable sensors or sonar. However, a post-lay detection is usually performed to confirm the actual buried depth.

[0006] The total force acting on a conventional screw down is usually measured with the aid of a shear pin load cell, which is usually in line with the raise / lower actuator (hydraulic cylinder) used to raise and lower the screw down. The force acting on the screw down is the result of the cable force and the soil force, which are generated by friction and soil overload (i.e. the interaction between the screw down and the cut soil created during the trenching process).

[0007] The load cell measures the force in the direction of its shear plane, which is set in a single orientation. These shear planes tend to fit a narrow range of indenter heights, so measuring the full height range is more difficult as this would rely on the load cell rotating in unison with the actuator.

[0008] Furthermore, the use of conventional screw downs has the disadvantage that operators often see high loads which they may attribute to high cable tension. In these cases, the trenching speed may be reduced, the burial depth may be reduced, or both, but these high forces may be caused by soil forces rather than cable tension, so a reduction in trenching speed and / or burial depth may not be necessary.

[0009] The preferred embodiment seeks to overcome this disadvantage.The present invention seeks to solve at least one known problem of the prior art.

[0010] According to one aspect of the present disclosure, there is provided an object engaging apparatus for engaging an elongated object inserted into a trench, the apparatus comprising: an object engaging device adapted to be mounted to the support and to engage an elongated object inserted into the trench; a restraining means for substantially preventing movement of the object engaging means relative to the support in a first direction caused by movement of the object engaging means relative to the elongate object in an axial direction of the elongate object; and A force measuring device is provided for providing an output dependent upon a force applied to the object engaging means in a second direction transverse to the first direction.

[0011] According to one aspect of the present invention, there is provided an object engaging apparatus for engaging an elongated object inserted into a ditch, the object engaging apparatus comprising: an object engaging device adapted to be mounted to the support and to engage an elongated object inserted into the trench; a restraining means for substantially preventing movement of the object engaging means relative to the support in a first direction caused by movement of the object engaging means relative to the elongate object in an axial direction of the elongate object; and A force measuring device is provided for providing an output dependent upon a force applied to the object engaging means in a second direction perpendicular to the first direction.

[0012] According to one aspect of the present invention, there is provided an object engaging apparatus for engaging an elongated object inserted into a ditch, the object engaging apparatus comprising: an object engaging device configured to be mounted to the support and configured to engage an elongated object inserted into the trench; restraining means for preventing, in use, movement of the object engaging means relative to the support in a first direction related to the axial direction of the elongate object being engaged; and A force measuring device is provided for measuring a force applied to the object engaging device in a second direction perpendicular to the first direction.

[0013] According to one aspect of the present invention, there is provided an object engaging apparatus for engaging an elongated object inserted into a ditch, the object engaging apparatus comprising: an object engager configured to be mounted to the support and configured to engage with the elongated object; a restraint for preventing movement of the object engager relative to the support in a first direction when in use; and A force sensor is provided for providing an output dependent upon a force applied to the object engager in a second direction perpendicular to the first direction.

[0014] According to another aspect of the present invention, there is provided an object engaging apparatus for engaging an elongated object inserted into a ditch, the object engaging apparatus comprising: an object engaging device configured to be mounted to the support and configured to engage an elongated object inserted into the trench; a restraining device for preventing movement of the object engaging device relative to the support member in a first direction; and A force measuring device is provided for measuring a force applied to the object engaging device in a second direction perpendicular to the first direction.

[0015] In some embodiments, the output from the sensor or force measuring device is a measurement of the force exerted thereon.

[0016] In some embodiments, the object engaging device or object engager is a cable shoe.

[0017] In some embodiments, multiple object engagement devices, object engagement devices, or cable boots are included. Advantageously, having multiple object engagement devices, object engagement devices, or cable boots can enable multiple force measurements along the length of the elongated object being lowered to the seabed, and thus facilitate more efficient detection of forces exerted on the elongated object (e.g., a cable) to detect stresses before they reach a critical point, and also to detect whether the lowering process can be accelerated without causing stresses.

[0018] In a preferred embodiment, the object engagement device or object engager or cable shoe is configured to be releasably attached or releasably mounted to a support. In a preferred embodiment, the object engagement device or object engager or cable shoe is configured to be releasably attached or releasably mounted to a support when in use. In a preferred embodiment, the object engager or cable shoe is configured to releasably engage with an elongated cable. In some embodiments, the object engager is configured so that when in use, the object engager will be releasably mounted to a support at a top portion of the object engager and releasably engage with an elongated object (e.g., a cable) at a lower portion of the object engager.

[0019] When in use, the object engaging means may be attached or mounted on a support.

[0020] In some embodiments, the object engager or object engaging device comprises a through hole or aperture configured to receive the force sensor. In some embodiments, the force measuring device or force sensor is configured to be receivable in the through hole of the engaging device or object engager.

[0021] In some embodiments, the object coupler includes a through hole that is configured to correspond to two corresponding through holes of the support member when in use. In some embodiments, the through hole of the object coupler is configured to be located at the top portion of the object coupler when in use. In some embodiments, the through hole of the object coupler is positioned at a portion of the object coupler that is opposite to the object engaging portion of the object coupler. In some embodiments, the through hole is configured so that the axis of the through hole in use spans the direction of travel or spans the axis of the elongated object being engaged when in use. In some embodiments, the through hole is configured so that the axis of the through hole in use is located on a horizontal plane that is perpendicular to the direction of travel when in use or is located on a horizontal plane that is perpendicular to the axis of the longitudinal object being engaged when in use.

[0022] In some embodiments, the object engager can be configured so that the through hole of the object engager is configured so that, when in use, the axis of the through hole is located in a horizontal plane with the two holes in the support. In some embodiments, the force sensor is configured to be received by the through hole of the object engager and the two corresponding holes of the support. In some embodiments, the force sensor is configured to attach the object engager to the support. In some embodiments, the force sensor is configured to be included in an attachment pivot point between the object engager and the support.

[0023] In some embodiments, the through hole of the object engager is configured to receive a force sensor.

[0024] In some embodiments, the force measuring device or force sensor is configured to be positionable in a through hole of an object engager or a cable shoe.

[0025] In some embodiments, the force measuring device or force sensor is configured to be received through the through hole of the object engager.

[0026] In some embodiments, the force measuring device or force sensor or load cell is configured to be received through two corresponding holes of the support when used with the support.

[0027] In some embodiments, the force sensor is configured to act as a releasable attachment means or attachment to releasably couple the engagement means to a support member in use.

[0028] In some embodiments, the force sensor is configured to function as a fixed pivot for attaching the object engaging device or object engager to the support.

[0029] In some embodiments, the force sensor comprises a load cell. Advantageously, this may enable the force applied to the load cell or force sensor to be measured. Advantageously, since the load cell or force sensor may be used as a joint or pivot for releasably attaching the adapter to the support when in use, the force sensor or load cell will receive all or nearly all of the vertical force applied to the load cell.

[0030] An advantage of a force sensor which, when used, may be used as a securing means for releasably attaching the object engager to the support is that there are fewer parts and the force sensor is able to give an accurate measurement of the force applied.

[0031] Using a load cell or force measuring device or force sensor in this manner and / or position and orientation allows the sensor to accurately measure the load force on it and thus this directly corresponds to the force exerted on the elongated object (e.g. cable). The load cell or force measuring device or force sensor can more accurately measure the downward force exerted on the elongated object (e.g. cable) because the measured value on the load cell is equal to or directly proportional to the downward force on the elongated object (e.g. cable).

[0032] In some embodiments, a controller or other device is included to transmit an alarm signal to a user, or to calculate and / or record the measurement value from the force sensor or force measuring element, force measuring device. Those skilled in the art will understand how these components can be connected and used to transmit the measurement value to the user or computer or alarm system.

[0033] In some embodiments, the restraining device or restraint comprises at least one protrusion from one side of the object engager, which is configured to be received in a corresponding slot of a corresponding support. In some embodiments, at least two protrusions from the object engager are included. Suitably, in some embodiments, there are two protrusions from opposite sides of the object engager, and these protrusions are configured to be received in the slot of the corresponding support when in use.

[0034] In some embodiments, the restraint or restraint comprises at least one pin configured to be releasably attached to the object engager. In some embodiments, the at least one pin configured to be releasably attached to the object engager is configured to be receivable in a corresponding slot of a corresponding support member when in use. Suitably, in some embodiments, there are two pins and these pins are configured to be attachable to opposite sides of the object engager and are configured to be receivable in corresponding slots of the support member when in use.

[0035] Advantageously, the projection or pin of the restraint is configured to be receivable in a corresponding slot of the support when in use, so that vertical movement of the object engager (including upward and downward movement, or including upward or downward movement at different times, or including both upward and downward movement at different times) is possible only within the slot, but other directions of movement are constrained. Thus, when in use, the force sensor acts like a pivot, enabling movement backwards and forwards along the direction of travel, or backwards and forwards along the axis of the engaged elongated object, but without movement of the axis of the engaged elongated object substantially transverse to the direction of travel when in use. The restraint constrains backwards and forwards movement along the direction of travel or along the axis of the engaged elongated object, so that when oriented in use, the only movement that remains possible is vertically upwards or downwards. Thus, advantageously, the present invention can more accurately determine that the vertical force is measured, with less interference from other forces in other directions.

[0036] In some embodiments, at least two restraining devices or restraints are included.

[0037] In some embodiments, the restraint restrains movement of the object engagement device or object engager relative to the support in a first direction. Advantageously, this restrains movement of the object engager or object engagement device in a rearward and forward direction along the axis of the elongate object being engaged (when in use), or restrains rearward and forward movement along a direction of travel when in use.

[0038] In some embodiments, the first direction includes rearward and forward directions along the axis of the engaged elongated object.

[0039] In some embodiments, the restraint prevents movement of the object engagement device or object engager relative to the support in a first direction. In some embodiments, the first direction is a forward or rearward direction along the axis of the engaged elongated object. Advantageously, this prevents movement of the object engager or object engagement device in a rearward and forward direction along the axis of the engaged elongated object, or in a direction of travel when in use.

[0040] By providing restraining means for substantially preventing movement of the object engaging means relative to the support in a first direction due to movement of the object engaging means relative to the elongate object in the axial direction of the elongate object and force measuring means for providing an output dependent on a force applied to the object engaging means in a second direction transverse or perpendicular to the first direction, this provides the advantage of more accurate measurement of radial forces applied to the object whilst largely ignoring forces applied to the object engaging means which are not caused by radial forces between the object engaging means and the elongate object. This in turn enables the risk of damage to the elongate object to be reduced.

[0041] In some embodiments, the second direction comprises a vertically upward or vertically downward direction.

[0042] In some embodiments, the second direction may include both a vertical upward direction and a vertical downward direction. The skilled person will appreciate that this may be at different times or instances.

[0043] By gravity, the elongated object will fall to the seabed or bottom of the body of water, and the downward force applied to the elongated object will assist in this motion and may increase the speed of the downward motion of the elongated cable.

[0044] The object engaging means may comprise an object engaging surface, wherein the restraining means is located adjacent to said object engaging surface.

[0045] This provides the advantage of a more effective reaction force applied to the object engaging means in the axial direction of the elongated object, so that the movement of the object engaging means relative to the support is substantially caused by forces between the object engaging means and the elongated object transversely or perpendicularly to the axial direction. This in turn enables a simple determination of the transverse or perpendicular force applied to the elongated object.

[0046] The restraining means may comprise at least one protrusion adapted to be located on one of the object engaging means and the support and adapted to engage the other of the object engaging means and the support.

[0047] The force measuring device may comprise at least one load cell.In some embodiments, the force measuring device of the force sensor comprises a load cell.

[0048] The apparatus may further comprise proximity detection means for detecting the proximity of an elongate object.

[0049] This provides the advantage of enabling the trajectory of the object to be determined, thereby reducing the risk of exceeding the minimum bending radius of the object, and enabling determination that there are no elongated objects in the ditch. This is particularly true when multiple proximity detectors are used along the length of the elongated object in conjunction with multiple engagement means of the object engager or cable shoe.

[0050] This provides the advantage of enabling the trajectory of the object to be determined, thereby reducing the risk of exceeding the minimum bending radius of the object, and enabling determination that no elongated objects are in the ditch.

[0051] In some embodiments, a proximity detection device or proximity detector is included. In some embodiments, the proximity detection device or proximity detector includes a metal detector. In some embodiments, the proximity detection device or proximity detector includes a magnet. In some embodiments, the proximity detection device or proximity detector includes a magnet, wherein the magnet is configured to detect metal at the lower surface of the object engagement device or object engager.

[0052] Advantageously, the proximity detector is able to differentiate the proximity of an elongated object, such as a cable, from other objects, such as soil or fish.

[0053] In practice, the elongated object to be lowered to the bottom of the body of water may be a cable comprising metal. Thus, in embodiments where the proximity detector (or proximity detection means) comprises a metal detector or a magnet, the proximity detector may distinguish between a cable being engaged by the object engager (or object engagement means) and other non-metallic objects such as fish or soil. This helps the user know whether the force measurement being detected is a force being applied to the elongated object (e.g., a cable comprising metal) or a false reading due to some other object.

[0054] In some embodiments, the apparatus of the present invention comprises plastic. In some embodiments, the object engaging device or object engaging device comprises plastic. In some embodiments, the restraining device or restraint comprises plastic. In some embodiments, the pin comprises plastic. In some embodiments, the force sensor comprises plastic.

[0055] It is helpful to accurately detect elongated objects containing metal, such as cables including metal, when the object engager is free of metal, particularly at the contact engagement portion of the object engager or object engaging device.

[0056] According to another aspect of the present disclosure, there is provided an object insertion device for inserting an elongated object into a ditch, the device comprising: a support adapted to be mounted to a vehicle body of a vehicle and movable relative to the vehicle to insert the elongated object into the ditch; and At least one object engaging device as defined above.

[0057] The object insertion device may comprise a plurality of said object engagement devices.

[0058] This provides the advantage of distributing the forces applied to the elongate object over a larger area, thereby minimising the risk of damage to the elongate object, and enabling the trajectory of the elongate object to be determined.

[0059] The object insertion apparatus may further comprise actuator means for moving the support relative to the vehicle body.

[0060] This provides the advantage that contact forces between the object engagement means and the elongate object caused by the weight of the object insertion apparatus can be reduced by actuation of the actuator means, thereby further reducing the risk of damage to the elongate object.

[0061] The support may be adapted to be pivotably mounted to the vehicle body.

[0062] According to another aspect of the present disclosure, there is provided a vehicle comprising a vehicle body and the object insertion apparatus as defined above.

[0063] The vehicle may also include a channel forming device.

[0064] The vehicle may also include movement means for moving the vehicle relative to the ditch.

[0065] According to another aspect of the present invention, there is provided a system for assisting the lowering of an elongate object to the seabed, wherein the system comprises: an apparatus as described herein.

[0066] According to another aspect of the present invention, there is provided a system for assisting the lowering of an elongated object to a seabed, wherein the system comprises: an object engaging apparatus comprising a cable shoe, wherein the cable shoe comprises a through hole configured to receive the force sensor and comprises an elongated object engaging surface configured to receive the elongated object; at least one pin configured to releasably attach to a side of the cable shoe; a support configured to be releasably attached to a vehicle, wherein the support includes at least one slot, wherein the at least one slot is configured to receive at least one of the pins, and the slot is configured to allow vertical movement of the pin within the confines of the slot but to restrict movement in other directions, the support further comprising at least two holes; A force sensor is configured to be receivable within the through hole of the engagement device and to be receivable through the two holes of the support member such that the force sensor releasably couples the engagement device to the support member.

[0067] Since the pin can be attached to the cable shoe or object engaging device during use, the slot also allows the cable shoe or object engaging device to move up and down, but prevents movement in other directions when used with a construction in which the object engaging device is coupled to the support via a force sensor, the force sensor including a pivot joint between the object engaging device and the support.

[0068] In some embodiments, the object engaging surface is positioned at a lower portion of the engaging apparatus or object engaging device or object engager.

[0069] In some embodiments, the object engaging surface of the engagement apparatus or object engaging device or object engager comprises a smooth surface. This helps to reduce friction and stress on the elongated object as it is lowered towards the bottom of the body of water.

[0070] In some embodiments of the system, the slot of the support is longer in the vertical direction than it is wide in the horizontal direction. This enables the pin or protrusion to move vertically within the confines of the slot when in use, and therefore enables the engagement device to move vertically when in use, while constraining other movement from other directions. Advantageously, this can help to more accurately measure the vertical force of an elongated object on the force sensor.

[0071] In some embodiments of the system, the width of the slot in the horizontal direction is only slightly wider than the wide diameter of the corresponding pin that the slot is configured to receive. This can allow the pin to move vertically up and down in the slot easily, but prevents horizontal movement.

[0072] In some embodiments of the system, the system further includes a vehicle configured to be attachable to the support.

[0073] In a particular embodiment of the system, the vehicle comprises a plough configured to form a ditch if dragged along the seabed.

[0074] In some embodiments of the system, the support is configured to move upward or downward or up and down in the body of water to help lower the elongated object to the seabed. In some embodiments of the system, the support is configured to have a variable weight to control the force applied to the elongated object. This can be achieved through buoyancy, reaction forces, or other means to actually have more or less downward force applied by the support.

[0075] In some embodiments of the system, the support member includes a hold down device.

[0076] In some embodiments of the system, the support is configured to include two holes which, in use, lie in a horizontal plane with the axis of the through hole of the cable shoe.

[0077] In some embodiments of the system, the support may include at least one slot. In some embodiments of the system, the slot of the support may be an open slot.

[0078] In some embodiments of the system, the support member includes at least one flange protruding downwardly. In some embodiments of the system, the support member includes at least one flange protruding downwardly. In some embodiments of the system, the support member includes at least one flange protruding downwardly, wherein at least two of the flanges are configured to receive an object engaging device or an object engager or an object engaging means between at least two of the flanges.

[0079] In some embodiments of the system, at least two flanges are oriented relative to each other.

[0080] In some embodiments of the system, each of the at least two (preferably two) flanges includes a hole that corresponds in position to a corresponding hole of the opposing flange. In some embodiments of the system, each of the at least two (preferably two) flanges includes a hole that corresponds in position to a corresponding hole of the opposing flange, the hole being configured so that the axes of the two corresponding holes are located in a horizontal plane and configured to receive a force sensor through the two corresponding holes. In a preferred embodiment, the horizontal axis of the corresponding hole of the support will be configured to be substantially in the same horizontal plane as the through hole of the object engager when in use.

[0081] In some embodiments of the system, the flanges of the support each include a slot or the slots. In some embodiments of the system, each slot on the flange is an open slot. In some embodiments of the system, the slots of the flanges are configured to receive a pin, wherein the pin is configured to be attached to the object engager when the object engager is positioned between the two flanges of the support.

[0082] In some embodiments of the system, the flange of the support comprises plastic.When using a proximity detector comprising a metal detector, this may facilitate detection of a cable comprising metal if the cable engages with an object engager or a cable shoe.

[0083] In another aspect of the invention there is provided a method of measuring vertical forces exerted on an elongate object as it is lowered to the bottom of a body of water, such as the sea bed, wherein the method comprises use of an apparatus or system as described herein.

[0084] In another aspect of the invention, there is provided a method of measuring the vertical force exerted on an elongated object as the elongated object is lowered to the bottom of a body of water (e.g., the seabed), wherein the method comprises the following steps: The elongated object to be lowered to the seabed is positioned beneath an engagement apparatus or system as described herein.

[0085] In another aspect of the invention, there is provided a method of measuring the vertical force exerted on an elongated object as the elongated object is lowered to the bottom of a body of water (e.g., the seabed), wherein the method comprises the following steps: An elongate object to be lowered to the seabed is positioned beneath an engagement apparatus, or object engagement device, or object engager or system as described herein.

[0086] To help understand the present invention, a general non-limiting example of the present invention will be described: the present invention can assist in the lowering of an elongated object, and can measure the force applied to the elongated object so as to prevent excessive stress from being applied to the elongated object when the elongated object is lowered. In some embodiments, an object coupler can be used, wherein the object coupler may include a through hole and at least one (preferably at least two) corresponding protrusions protruding from at least one side of the object coupler. In some preferred embodiments, the protrusions are replaced by one or more pins to make the mating of the object coupler easier. In an embodiment with a pin, ideally, the pin can be releasably attached to at least one side of the object coupler. In some embodiments, the pin or protrusion is configured to be received in a corresponding groove of the support when in use. In some embodiments, the object engagement device or system also includes a force sensor, which can be a force measuring element, and the force sensor or force measuring element can be configured to be received in a through hole of the object engagement device or object coupler. The object coupler can be configured so that the through hole can correspond to two holes in the support in the horizontal plane, so that the force sensor configured to be received by the through hole of the object coupler and the two corresponding holes of the support can attach the object coupler to the support, including the attachment pivot point. This type of attachment pivot point of the object coupler and the support can allow backward and forward movement if it is not constrained. Suitably, in some embodiments, the object coupler or the engagement device and the support can be configured so that the forward and backward movement will be in the axial direction of any elongated object engaged to the object coupler. In some embodiments, there is a restrainer. In some embodiments, the restrainer can include a pin and slot type arrangement in whole or in part, or be configured to realize a pin and slot type arrangement. In some embodiments, the object coupler includes at least one protrusion or pin, and the at least one protrusion or pin is configured to be received by the corresponding slot on the corresponding support. Thus, in some embodiments of an arrangement comprising a force sensor that attaches the object engager to the pivot joint of the support and a restraint that prevents the object engager from moving backwards and forwards in the axial direction of the elongated object when the elongated object is engaged to the object engager, substantially the only movement left is thus an up and down vertical movement, the spacing of which is limited by the internal vertical length of the slot. When combined with or used with the present invention, this can enable the force sensor to more accurately measure the downward force exerted on the elongated object.

[0087] In alternative embodiments, the arrangement of the protrusions or pins and slots can be reversed. In some alternative embodiments, the object engager includes a slot configured to receive a pin or receive a protrusion on the support. Having separate pins and slots on the support can help to assemble the object engager to the support. If the protrusions of the restraining device or restraint are fixed, these protrusions can still be positioned in place by friction fit, especially in embodiments where the engaging device or object engager includes plastic.

[0088] Any one or more features of any example, aspect or embodiment of the invention as described herein may be combined with any other one or more features of any other example, aspect or embodiment of the invention as described herein.

[0089] The term "engagement" as used herein with respect to an elongate object being joined or a cable being joined means the engagement when, in use, the elongate object or cable is joined to an engagement device or an adapter or a cable shoe.

[0090] The term "first direction" as used herein with respect to the movement of a coupling device or object coupling device or the like is used to mean, in use, movement backwards and forwards, or including movement backwards and / or including movement forwards, or movement backwards and forwards, along the axis of the elongated object when the elongated object is coupled to the apparatus, system or coupling device or coupling device. When using the present invention, this will also be movement backwards and / or forwards along the direction of travel.

[0091] As used herein, the terms "force measuring device" and "force sensor" are used interchangeably and have the same meaning, an example of which is a force measuring cell.

[0092] The terms "object engaging device" and "object engager" are used interchangeably and mean the same thing. An example of an "object engaging device" and / or "object engager" is a cable shoe.

[0093] As used herein, the terms "constraint" and "constraint" are used interchangeably and have the same meaning. A restraint may, for example, partially or completely comprise a pin and slot arrangement, one component of which may be on or attached to an object attachment device or object engager and the other component of which may be attached to a support to which it is attached in use.

[0094] When used in reference to movement of a coupling or coupling device or apparatus etc., the term "a second direction transverse or perpendicular to the first direction" refers to a vertical direction, including upward and including downward, or up and down, or vertically up or down, such as when in use, and when oriented for use.

[0095] As used herein, terms such as "top" and "lower" are used to refer to the orientation of the object engagers, devices and systems of the present invention when in use, when oriented for use. These terms are used to help explain the present invention and are not necessarily limiting.

[0096] Preferred embodiments will now be described by way of example only and not in any limiting sense with reference to the following drawings, in which: Figure 1 is a schematic side cross-sectional view of a cable buried vehicle of an embodiment; Figure 2 yes Figure 1 A side sectional view of a depressor of a vehicle; Figure 3 is along Figure 2 A view of line XX in FIG. 1 ; and Figure 4 is along Figure 3 Sectional view along line YY in FIG.

[0097] Figure 5 are views of examples of cable shoe embodiments and attachment features according to the present invention.

[0098] Figure 6 is a side cross-sectional view of an example of a cable shoe and attachment feature according to the present invention.

[0099] Referring to the accompanying drawings, the cable 4 is used to bury the cable 4 in the seabed 8 ( Figure 2 ) has a vehicle body 10, a trench forming device in the form of a jet sword 12 mounted to the vehicle body 10, and a moving device in the form of a track 14 for moving the vehicle 2 relative to the trench 6. An object insertion device in the form of a pusher 16 for inserting the cable 4 into the trench 6 includes a support 18 which is pivotally mounted to the vehicle body 10 and is raised or lowered relative to the vehicle body 10 by means of an actuator device in the form of a hydraulic actuator 20.

[0100] The presser 16 comprises an object engaging device in the form of a plurality of cable shoes 22 mounted at the lower portion of the support 18. The cable shoes 22 have object engaging means in the form of cable shoe contact surfaces 24 and are positioned so that the cable shoe contact surfaces form an arc whose radius is equal to or greater than the minimum allowable bending radius of the cable 4. Each cable shoe contact surface 24 may also be shaped to the minimum bending radius of the cable 4. The cable shoes 22 may be provided with a proximity sensor 26 ( Figure 3 ) in the form of a proximity detection device for detecting the presence of the cable 4. In this case, the cable shoe 22 is made of a material that is not detected by the proximity sensor 26.

[0101] Each cable shoe 22 is mounted on the support 18 by means of a force measuring device in the form of a shear pin load cell 28, and the rotation of each cable shoe 22 about the corresponding load cell 28 (equivalent to the movement of the cable shoe 22 relative to the support 18 in the axial direction of the cable 4) is limited by a restraining device in the form of one or more dowel pins 30, which are positioned substantially in line with the corresponding cable shoe contact surface 24. The clearance between the dowel pins 30 and the cable shoe 22 or the support 18 allows a limited movement of the cable shoe 22 in a second direction transverse to or perpendicular to the first direction. Therefore, the cable friction is only reacted by the dowel pins 30 and not by the load cell 28, with the result that the load cell 28 is substantially only subjected to a load in the direction of its corresponding shear plane and thus measures the real contact force between the cable 4 and the cable shoe 22, i.e. the radial load applied to the cable 4 in a direction transverse to or perpendicular to its axis.

[0102] In the case of mating, the proximity sensor 26 detects and verifies the presence of the cable 4 to ensure that the load pin reading of the load cell 28 refers to the cable contact and not pure soil contact force. The shoe proximity sensor 26 and the load cell 28 are monitored separately and the contact position is thus defined and the load pin force is measured at a specific location. This gives an indication of the shape of the cable catenary through the laying process.

[0103] The cable radial load can be reduced by applying hydraulic pressure to the actuator 20 (typically on the annular side of the lift cylinder of the actuator 20) to reduce the submerged weight of the hold-down 16, and therefore reduce the cable contact force, thereby reducing the risk of damaging the cable 4. Although the hold-down 16 will only exert a limited downward force on the cable 4, the cable burial depth can still be measured.

[0104] Figure 5 and Figure 6Another embodiment of a cable shoe 22 embodiment of the present invention is shown. As can be seen in this embodiment, the cable shoe 22 is positioned between two flanges 18a of the support 18. The flange 18a of the support 18 includes a through hole 32 capable of receiving a force sensor, in this embodiment, a load cell 28. The flange 18a of the support 18 also includes a slot 33 configured to receive a pin 30. The pin 30 is configured to be received by the slot 33 and releasably attached to the object engager / cable shoe 22. In this example, the cable shoe 22 includes a plastic material. In this example, the flange 18a of the support 18 includes plastic. A proximity sensor 26 is also shown that can verify the presence or absence of the cable 4 to ensure that the load / force reading of the load cell 28 is obtained by the cable 4 contact and not any other object (such as soil). In this example, the proximity sensor 26 is capable of detecting the presence of metal in the area of ​​the contact surface 24 of the cable shoe 22, and therefore can detect any cable 4 containing metal. Thus, the proximity sensor 26 can distinguish between the presence of the cable 4 containing metal and the presence of other non-metallic items, such as soil. Figure 5 and Figure 6 The cable shoe 22 embodiment of the present invention can also be releasably attached or mounted to the support 18 by means of a force measuring device, and in this example this is achieved by means of a shear pin load cell 28. The shear pin load cell 28 is received in a through hole 34 of the cable shoe 22. As can be seen by the dotted lines, the axis of the through hole 34 of the cable shoe 22 and the corresponding hole in the flange 18a of the support 18 lie in one horizontal plane, so that the load cell 28 is received by both corresponding holes of the support 18 and the through hole 34 of the cable shoe 22. The shear pin load cell 28 is used to attach the cable shoe 22 to the support 18 via the flange 18a of the support 18. When in use, the support 18 is mostly located above the cable shoe and the cable, with the flange 18a being located on the upper side of the cable shoe. In this embodiment, the load cell 28 is used as a pivot joint to attach the cable shoe 22 to the support 18. Only by this attachment can the cable shoe 22 be pivoted forward and backward along the axis or direction of travel of the engaged cable 4. However, this is limited by the pin 30 and its corresponding Figure 633 is prevented by the slot 33 seen around the pin 30 in the support 18. In this embodiment, the slot 33 is an opening in the support 18 or the flange 18a of the support 18. The locating pin 30 prevents axial movement of the cable shoe 22, in other words, prevents the cable shoe 22 from pivoting in the rearward and forward directions of the vehicle direction when in use. The locating pin 30 can move upward or downward in the vertical direction within the slot 33. This enables the cable shoe 22 to move only in a vertical, upward or downward movement when in use, and therefore the shear pin load cell 28 only measures the vertical load pressure thereon. The shear pin load cell 28 is able to monitor and measure the force applied thereto. This is equal to or directly proportional to the force applied to the elongated object or cable when engaged to the cable shoe. In this embodiment, the support 18 is configured to include two holes 32, which are located in a horizontal plane with the axis of the through hole 34 of the cable shoe 22.

[0105] The invention will be described by the following non-exhaustive list of examples, which does not exclude or limit other examples and embodiments of the invention.

[0106] Example 1. An object engaging apparatus for engaging an elongated object inserted into a ditch, the apparatus comprising: an object engaging device adapted to be mounted to the support and to engage an elongated object inserted into the trench; a restraining means for substantially preventing movement of the object engaging means relative to the support in a first direction caused by movement of the object engaging means relative to the elongate object in an axial direction of the elongate object; and A force measuring device is provided for providing an output dependent upon a force applied to the object engaging means in a second direction transverse or perpendicular to the first direction.

[0107] 2. An apparatus according to example 1, wherein the object engaging device includes an object engaging surface, and wherein the restraining device is positioned adjacent to the object engaging surface.

[0108] 3. An apparatus according to example 1 or 2, wherein the restraining device includes at least one protrusion, the at least one protrusion being adapted to be located on one of the object engaging device and the support and to engage the other of the object engaging device and the support.

[0109] 4. Apparatus according to any of the preceding examples, wherein the force measuring device comprises at least one force measuring cell.

[0110] 5. The apparatus according to any of the preceding examples further comprises a proximity detection device for detecting the proximity of the elongated object.

[0111] 6. An object insertion device for inserting an elongated object into a ditch, the device comprising: a support adapted to be mounted to a vehicle body of a vehicle and movable relative to the vehicle to insert the elongated object into the ditch; and At least one object engaging apparatus according to any of the preceding numbered examples.

[0112] 7. The device according to Example 6 includes a plurality of the object engaging devices.

[0113] 8. The apparatus of example 6 or 7 further comprising an actuator arrangement for moving the support relative to the vehicle body.

[0114] 9. An apparatus as described in any one of Examples 6 to 8 wherein the support member is adapted to be pivotally mounted to the vehicle body.

[0115] 10. A vehicle comprising a vehicle body and an object insertion device according to any one of Examples 6 to 9.

[0116] 11. The vehicle according to Example 10 further includes a ditch forming device.

[0117] 12. The vehicle of example 10 or 11 further comprising a moving device for moving the vehicle relative to the ditch.

[0118] Those skilled in the art will appreciate that the above embodiments are only described by way of example and not in any limiting sense, and that various changes and modifications are possible without departing from the scope of the present disclosure as defined in the appended claims.

Claims

1. An object engaging apparatus for engaging an elongated object inserted into a ditch, the object engaging apparatus comprising: an object engaging device configured to be mounted to the support and configured to engage an elongated object inserted into the trench; a restraining device for preventing the object engaging device from moving in a first direction relative to the support member; and A force measuring device is provided for measuring a force applied to the object engaging device in a second direction perpendicular to the first direction.

2. The device according to claim 1, wherein The object engaging device includes an object engaging surface, wherein the restraining device is located adjacent to the object engaging surface.

3. The device according to claim 1 or 2, wherein: The restraining device includes at least one protrusion configured to be releasably attached to a side of the object engaging device and configured to be received by a slot of a support member.

4. The device according to any one of the preceding claims, wherein: The force measuring device comprises at least one force-measuring cell.

5. Apparatus according to any preceding claim, further comprising proximity detection means for detecting the proximity of the elongate object.

6. The device according to claim 4, wherein: The force sensing cell is configured to be receivable in a hole in the object engaging device.

7. The device according to claim 4 or 6, wherein: The force-measuring cell is configured to be receivable through two corresponding holes of the support.

8. The device according to claim 5, wherein: The proximity detection device includes a metal detection sensor.

9. An object insertion system for inserting an elongated object into a ditch, the device comprising: a support configured to be mounted to a vehicle body of a vehicle and movable relative to the vehicle to insert the elongated object into the ditch; and At least one object engaging device according to any of the preceding claims or claims 17 or 18.

10. Apparatus according to claim 9, comprising a plurality of said object engaging apparatus.

11. Apparatus according to claim 9 or 10, further comprising actuator means for moving the support relative to the vehicle body.

12. The apparatus according to any one of claims 9 to 11, wherein: The support is adapted to be pivotally mounted to the vehicle body.

13. A vehicle comprising a vehicle body and an object insertion device according to any one of claims 9 to 12.

14. The vehicle of claim 13, further comprising a channel forming device.

15. A vehicle as claimed in claim 13 or 14, further comprising movement means for moving the vehicle relative to the ditch.

16. A method of measuring the forces exerted on an elongated object being lowered to the seabed, comprising the steps of: An elongate object to be lowered to the sea bed is positioned beneath an object engaging apparatus as claimed in any one of claims 1 to 8 or claim 17 or 18.

17. The apparatus according to any one of claims 1 to 8, wherein: The first direction is a rearward or forward direction, or a direction of travel, along a longitudinal axis of an elongate object when the elongate object is engaged to the engagement apparatus or object engager in use.

18. The apparatus according to any one of claims 1 to 8, wherein: The second direction is a vertical direction, upward or downward.

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