Device for inserting a long object into a trench

Abstract

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

Description

Technical Field

[0001] The present disclosure relates to an apparatus for inserting a long object into a trench, and more particularly, but not exclusively, to an apparatus for inserting a cable into a trench at the bottom of a water body such as the seabed.

Background Art

[0002] Lowering a cable into a trench formed by a trenching vehicle can be achieved either passively (by relying on the self-weight of the cable) or actively, i.e., by actively inserting the cable into the trench using a mechanical arm known as a depressor attached to the trenching vehicle.

[0003] Lowering by self-weight has an advantage over the use of an active depressor in that there is no physical contact between the cable and the depressor, thus reducing the risk of damage to the cable. Specifically, in the case of lowering by self-weight, the cable is less bent compared to passing around the depressor, while in the case of the depressor, the cable is bent in an "S" shape, which may damage the cable.

[0004] Another advantage of lowering by self-weight is the elimination of the radial load on the cable, which can pose a significant risk of damage to the cable. For example, some power cables are sensitive to radial loads, i.e., forces acting perpendicular to the axis of the cable. Cable manufacturers often specify load limits that must not be exceeded during the laying and burial process. For this reason, the magnitude of the downward force applied to the cable by the depressor must be quantified and limited. In one example, the depressor only acts as a sensor to determine the cable position, i.e., the burial depth.

[0005] Conversely, the use of a depressor provides one or more advantages against gravity-driven descent. Specifically, gravity-driven descent can involve an increase in the number of trenching paths required to lower the cable to the necessary depth. Each path lowers the cable a certain distance depending on the weight of the cable, the diameter of the cable, the strength and composition of the soil, how effectively the trench is jetted (to fluidize debris in the trench), the cable tension, and the trenching speed. Without a depressor in contact with the cable, it is more difficult to measure the depth of burial. Cable depth can be measured using mounted surveying equipment and can typically be measured using a cable sensor or sonar. However, post-laying surveys are often performed to confirm the actual burial depth.

[0006] The total force acting on a conventional depressor is typically measured using a shear pin load cell typically attached in series with a lift / lower actuator (hydraulic cylinder) for raising and lowering the depressor. The force acting on the depressor is the combined cable force and the soil force generated by friction and soil addition, i.e., the soil force generated by the interaction between the depressor and the cut soil 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 conform to a narrow range of depressor heights, and as a result, measuring over the full range of heights is more difficult because it relies on a load cell that rotates in series with the actuator.

[0008] In addition, the use of conventional depressors has the drawback that operators often witness large loads that can cause significant cable tension. In these situations, not only the trench formation speed but also the burial depth can be reduced, or both can be reduced, but these large forces may result from soil forces rather than cable tension, and as a result, the reduction in trench formation speed and / or burial depth may be unnecessary.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] Preferred embodiments seek to overcome this drawback. The present invention seeks to address at least one of the known problems of the prior art.

MEANS FOR SOLVING THE PROBLEMS

[0010] According to an aspect of the present disclosure, an object engaging device for engaging a long object inserted into a trench, object engaging means adapted to be mounted on a support and to engage a long object inserted into the trench, deterring means for substantially preventing movement of the object engaging means relative to the support in a first direction as a result of movement of the object engaging means relative to the long object in the axial direction of the long object, and force measuring means for providing an output that depends on a force applied to the object engaging means in a second direction transverse to the first direction is provided.

[0011] According to an aspect of the present invention, an object engaging device for engaging a long object inserted into a trench, object engaging means adapted to be mounted on a support and to engage a long object inserted into the trench, A restraining means for substantially preventing the movement of the object engaging means relative to the support in a first direction as a result of the movement of the object engaging means relative to the long object in the axial direction of the long object, and a force measuring means for providing an output depending on the force applied to the object engaging means in a second direction perpendicular to the first direction An object engaging device is provided.

[0012] According to an aspect of the present invention, there is provided an object engaging device for engaging a long object inserted into a trench, - Object engaging means configured to be mountable on a support and engageable with a long object inserted into a trench, - Restraining means for preventing the movement of the object engaging means relative to the support in a first direction with respect to the axial direction of the engaged long object during use, and force measuring means for measuring the force applied to the object engaging means in a second direction perpendicular to the first direction An object engaging device is provided.

[0013] According to an aspect of the present invention, there is provided an object engaging device for engaging a long object inserted into a trench, - An object engageable configured to be mountable on a support and engageable with a long object, - A stopper for preventing the movement of the object engageable relative to the support in a first direction during use, - A force sensor for providing an output depending on the force applied to the object engageable in a second direction perpendicular to the first direction An object engaging device is provided.

[0014] According to another aspect of the present invention, there is provided an object engaging device for engaging a long object inserted into a trench, - Object engaging means configured to be mountable on a support and engageable with a long object inserted into a trench, - deterrence means for preventing the movement of the object engaging means relative to the support in the first direction, - force measuring means for measuring the force applied to the object engaging means in a second direction perpendicular to the first direction An object engaging device is provided that includes the above.

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

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

[0017] In some embodiments, a plurality of object engaging means, object engages, or cable shoes are provided. Advantageously, by providing a plurality of object engaging means, object engages, or cable shoes, it is possible to perform a plurality of force measurements along the length of the elongate object to be lowered to the seabed, and thus to assist in a more effective detection of the force exerted on the elongate object such as a cable in order to detect the stress before it reaches the critical point, and also to assist in determining whether the lowering process can be accelerated without causing stress.

[0018] In a preferred embodiment, the object engaging means, object engage, or cable shoe is configured to be removably attachable to or removably mounted on the support. In a preferred embodiment, the object engaging means, object engage, or cable shoe is configured to be removably attachable to or removably mounted on the support when in use. In a preferred embodiment, the object engage or cable shoe is configured to be removably engageable with an elongate cable. In some embodiments, the object engage is configured to be removably mounted on the support at the upper portion of the object engage and removably engaged with an elongate object such as a cable at the lower portion of the object engage when in use.

[0019] The object engaging means can be attached or mounted to the support when in use.

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

[0021] In some embodiments, the object engaging device comprises a through hole configured to correspond to two corresponding through holes of the support when in use. In some embodiments, the through hole of the object engaging device is configured to be in the upper portion of the object engaging device when in use. In some embodiments, the through hole of the object engaging device is positioned in a portion of the object engaging device opposite the object engaging portion of the object engaging device. In some embodiments, the through hole is configured such that during use, the axis of the through hole intersects the direction of travel, or intersects the axis of the elongated object being engaged when in use. In some embodiments, the through hole is configured such that during use, the axis of the through hole lies in a horizontal plane perpendicular to the direction of travel when in use, or perpendicular to the axis of the engaged longitudinal object when in use.

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

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

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

[0025] In some embodiments, the force measuring means or force sensor is configured to be receivable through a through hole of the object engaging device.

[0026] In some embodiments, the force measuring means, force sensor, or load cell is configured to be receivable through two corresponding holes of the support when in use.

[0027] In some embodiments, the force sensor is configured to act as a releasable attachment means or fixture for releasably coupling the engaging means to the support when in use.

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

[0029] In some embodiments, the force sensor comprises a load cell. Advantageously, this can enable the force exerted on the measured load cell or force sensor. Advantageously, since the load cell or force sensor can act as a coupling point or pivot axis for releasably attaching the coupler to the support when in use, the force sensor or load cell will receive all or almost all of the vertical forces exerted on the load cell.

[0030] The advantage that the force sensor can act as a fixing means for releasably attaching the object engaging device to the support when in use is that there are fewer parts and the force sensor can provide an accurate measurement of the force exerted.

[0031] By this method and / or by using a load cell, force measuring means, or force sensor in terms of position and orientation, the sensor can accurately measure the force of the load on itself, and thus, this corresponds to the force exerted on an elongated object such as a cable and is oriented in the corresponding direction. Since the measurement in the load cell is equivalent to or is directly proportional to the downward force on an elongated object such as a cable, the load cell, force measuring means, or force sensor can more accurately measure the downward force exerted on an elongated object such as a cable.

[0032] In some embodiments, a control device or other means is provided to transmit to a user, warning signal, or computer and / or to record measurements from the force sensor, load cell, or force measuring means. Those skilled in the art will understand how these components can be connected and used to transmit measurements to a user, computer, or warning system.

[0033] In some embodiments, the detaining means or detainer comprises at least one protrusion from the side surface of the object engaging member, and the protrusion is configured to be receivable in a corresponding slot of a corresponding support. In some embodiments, at least two protrusions from the object engaging member are provided. Appropriately, in some embodiments, there are two protrusions from opposite side surfaces of the object engaging member, and these protrusions are configured to be receivable in the slots of the corresponding support when in use.

[0034] In some embodiments, the detent means or detent includes at least one pin configured to be removably attachable to the object engaging member. In some embodiments, at least one pin configured to be removably attachable to the object engaging member is configured to be receivable within a corresponding slot of a corresponding support when in use. Suitably in some embodiments, there are two pins, these pins being configured to be attachable to opposite sides of the object engaging member and configured to be receivable within corresponding slots of the support when in use.

[0035] Advantageously, the protrusion or pin of the detent is configured to be receivable within a corresponding slot of the support when in use such that vertical movement of the object engaging member, including up and down, or including upward, downward, or both, at different times is possible within the slot, but movement in other directions is inhibited. Thus, when in use, the force sensor acts like a pivot axis that allows movement backward and forward along the direction of travel, or backward and forward along the axis of the elongated object being engaged, but does not allow movement substantially horizontal to the axis of the elongated object being engaged in the direction of travel when in use. The detent inhibits movement backward and forward along the direction of travel, or along the axis of the elongated object being engaged, and thus the only movement still possible is vertical, up or down, when oriented in use. Thus, advantageously, the present invention can more accurately determine that vertical forces, with less interference from other forces from other directions, are being measured.

[0036] In some embodiments, at least two detent means or detents are provided.

[0037] In some embodiments, the stopper inhibits movement of the object engaging means or object engagee relative to the support in a first direction. Advantageously, this inhibits movement of the object engagee or object engaging means in a rearward and forward direction along the axis of the elongate object being engaged (when in use), or inhibits rearward and forward movement along the direction of travel when in use.

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

[0039] In some embodiments, the stopper prevents movement of the object engaging means or object engagee relative to the support in a first direction. In some embodiments, the first direction is a rearward direction and a forward direction along the axis of the elongate object being engaged. Advantageously, this prevents movement of the object engagee or object engaging means in a rearward and forward direction along the axis of the elongate object being engaged, or prevents rearward and forward movement along the direction of travel when in use.

[0040] By providing a restraining means for substantially preventing movement of the object engaging means relative to the support in a first direction as a result of movement of the object engaging means relative to the elongate object in the axial direction of the elongate object, and a force measuring means for providing an output depending 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 accurately measuring the radial force applied to the object while largely ignoring the force applied to the object engaging means that is not caused by a radial force between the object engaging means and the elongate object. This can further reduce the risk of damage to the elongate object.

[0041] In some embodiments, the second direction includes a vertical upward or downward direction.

[0042] In some embodiments, the second direction may include both an upward direction and a downward direction in the vertical direction. One skilled in the art will understand that this can be at different times or instants.

[0043] Due to gravity, the elongate object will sink towards the seabed, or the bottom of the water body, and the downward force exerted on the elongate object will assist this movement and can increase the speed of the downward movement of the elongate cable.

[0044] The object engaging means may comprise an object engaging surface, and the restraining means is positioned adjacent to the 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 elongate object such that movement of the object engaging means relative to the support is substantially caused by a force transverse or perpendicular to the axial direction between the object engaging means and the elongate object. This further enables an easy determination of the transverse or perpendicular force applied to the elongate object.

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

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

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

[0049] This can determine the trajectory of the object, thereby providing the advantage of reducing the risk of exceeding its minimum bending radius and can determine the absence of the elongate object in the trench. This is particularly so when some proximity detectors are used along the length of the elongate object when engaged with some engaging means, object engagors, or cable shoes.

[0050] This can determine the trajectory of an object, thereby providing the advantage of reducing the risk of exceeding its minimum bending radius, and can determine the absence of a long object in the trench.

[0051] In some embodiments, proximity detection means or a proximity detector is provided. In some embodiments, the proximity detection means or the proximity detector comprises a metal detector. In some embodiments, the proximity detection means or the proximity detector comprises a magnet. In some embodiments, the proximity detection means or the proximity detector comprises a magnet, and the magnet is configured to detect metal on the lower surface of the object engagement means or the object engage.

[0052] Advantageously, the proximity detector may be able to distinguish between the proximity of a long object such as a cable and the proximity of other objects such as soil or fish.

[0053] In fact, the long object lowered to the bottom of the water body may be a cable containing metal. Therefore, in embodiments where the proximity detector (or proximity detection means) comprises a metal detector or a magnet, the proximity detector can distinguish between a cable engaged with the object engage (or object engagement means) and other non-metallic objects such as fish or soil. This helps the user know whether the detected force measurement is the force exerted on a long object such as a cable containing metal or a false reading by some other object.

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

[0055] It is beneficial to accurately detect a long object containing metal, such as a cable containing metal, when the object engaging device has no metal, particularly at the contact engaging portion of the object engaging device or in the object engaging means.

[0056] According to another aspect of the present disclosure, there is provided an object insertion device for inserting a long object into a trench, a support adapted to be mounted on a vehicle body of a vehicle and to be movable relative to the vehicle for inserting a long object into a trench, at least one object engaging device as defined above and an object insertion device comprising the same is provided.

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

[0058] This provides the advantage that the risk of damage to the long object can be minimized and the trajectory of the long object can be determined by distributing the force applied to the long object over a larger area.

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

[0060] This provides the advantage that the contact force between the object engaging means and the long object caused by the weight of the object insertion device can be reduced using the operation of the actuator means, and thus the risk of damage to the long object can be further reduced.

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

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

[0063] The vehicle may further comprise trench forming means.

[0064] The vehicle may further include moving means for moving the vehicle relative to the trench.

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

[0066] According to another aspect of the present invention, there is provided a system for assisting the lowering of a long object to the seabed, the system comprising: - an object engaging device comprising a cable shoe, the cable shoe having a through hole configured to receive a force sensor and a long object engaging surface configured to receive a long object; - at least one pin configured to be releasably attachable to a side surface of the cable shoe; - a support configured to be releasably attachable to the vehicle, the support having at least one slot, the at least one slot being configured to receive the at least one pin, the slot being configured to allow vertical movement of the pin within the limits of the slot while inhibiting movement in other directions, the support further having at least two holes; - a force sensor configured to be received within the through hole of the engaging device and to be received through the two holes of the support so as to releasably couple the engaging device to the support. A system comprising the above is provided.

[0067] The pin can be attached to the cable shoe or the object engaging device during use, so that the slot also allows the cable shoe or the object engaging device to move up or down, but inhibits movement in other directions during use in the structure of the object engaging device coupled to the support by a force sensor including a pivotal connection between the object engaging device and the support.

[0068] In some embodiments, the object engaging surface is positioned below a portion of the engaging device, the object engaging means, or the object engage.

[0069] In some embodiments, the object engaging surface of the engaging device, the object engaging means, or the object engageable is provided with a smooth surface. This helps to reduce friction and stress in the elongate object when the elongate object is lowered towards the bottom of the water body.

[0070] In some embodiments of the system, the slots in the support are longer in the vertical direction rather than wider in the horizontal direction. This allows for vertical movement of the pins or protrusions within the limits of the slots during use, thus inhibiting other movements from other directions while allowing vertical movement of the engaging device during use. Advantageously, this can assist in more accurate measurement of the vertical force of the elongate object on the force sensor.

[0071] In some embodiments of the system, the width of the slot in the horizontal direction is slightly wider than the diameter of the width of the corresponding pin configured to be received by the slot. This can allow for easy up and down vertical movement of the pin within the slot but can prevent horizontal movement.

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

[0073] In certain embodiments of the system, the vehicle comprises a plow configured to be able to form a trench when towed along the seabed.

[0074] In some embodiments of the system, the support is configured to be movable up or down or to move up and down in the water body to assist in lowering the elongate object to the seabed. In some embodiments of the system, the support is configured to have a variable weight to control the force exerted on the elongate object. This can be achieved by buoyancy, reaction force, or other means to actually have a greater or smaller downward force applied by the support.

[0075] In some embodiments of the system, the support comprises a depressor.

[0076] In some embodiments of the system, the support is configured to have two holes in a horizontal plane along the axis of the cable shoe penetration hole when in use.

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

[0078] In some embodiments of the system, the support comprises at least one flange projecting downward. In some embodiments of the system, the support comprises at least one flange projecting downward, and at least two flanges are configured to receive an object engagement device, an object engageor, or object engagement means between at least two of said flanges.

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

[0080] In some embodiments of the system, at least two, preferably two, flanges have holes that are positioned corresponding to the corresponding holes of the opposite flange. In some embodiments of the system, at least two, preferably two, flanges have holes that are positioned corresponding to the corresponding holes of the opposite flange, are configured such that the axes of the two corresponding holes are in a horizontal plane, and are configured such that a force sensor can be received through the two corresponding holes. In a preferred embodiment, the horizontal axis of the corresponding hole in the support is configured to be in substantially the same horizontal plane as the through-hole of the object engaging device when in use.

[0081] In some embodiments of the system, the flanges of the support each comprise a slot. In some embodiments of the system, each slot in the flange is an open slot. In some embodiments of the system, the slots in the flange are configured to receive a pin, and the pin is configured to be attachable to the object engaging device when the object engaging device is positioned between the two flanges of the support.

[0082] In some embodiments of the system, the flanges of the support comprise plastic. This can assist in the detection of a cable containing metal when a proximity detector comprising a metal detector is used and the cable is engaged with the object engaging device or cable sheath.

[0083] In another aspect of the present invention, there is provided a method of measuring the vertical force exerted on an elongate object when descending to the bottom of a water body such as the seabed, the method comprising the step of using an apparatus or system as described herein.

[0084] In another aspect of the present invention, there is provided a method of measuring the vertical force exerted on an elongate object when descending to the bottom of a water body such as the seabed, - comprising the step of positioning an elongate object to be lowered to the seabed under an engagement device or system as described herein.

[0085] In another aspect of the present invention, there is provided a method for measuring a vertical force exerted on an elongate object when it is lowered to the bottom of a water body such as the seabed, the method comprising: - positioning an elongate object to be lowered to the seabed under an engagement device, object engagement means, object engaging member, or system as described herein.

[0086] To assist in the understanding of the present invention, one general non-limiting example of the present invention is described, where the lowering of a long object can be assisted by the present invention, and the force exerted on the long object can be measured to prevent excessive stress on the long object when the long object is being lowered. In some embodiments, an object engaging device may be used, and the object engaging device may comprise a through hole and at least one, preferably at least two corresponding protrusions protruding from at least one side of the object engaging device. In some preferred embodiments, the protrusions are replaced by one or more pins to make it easier to fit the object engaging device. In embodiments with pins, ideally, the pins can be releasably attached to at least one side of the object engaging device. In some embodiments, the pins or protrusions are configured to be received in corresponding slots of a support when in use. In some embodiments, the object engaging device or system further comprises a force sensor which can be a load cell, and this force sensor or load cell can be configured to be received in the through hole of the object engaging means or object engaging device. The object engaging device can be attached to a support having a pivot point for attachment such that a force sensor configured to be received by the through hole of the object engaging device and two corresponding holes of the support can have the through hole corresponding to the two holes in the support in a horizontal plane. This type of pivot point attachment between the object engaging device and the support can allow for movement in the rearward and forward directions if not restrained. Appropriately, in some embodiments, the object engaging device or engaging means and the support can be configured such that the movement in the front and rear directions is axial with respect to the long object engaged by the object engaging device. In some embodiments, there is a stopper. In some embodiments, the stopper can comprise, in whole or in part, an arrangement of the pin and slot type, or can be configured to allow an arrangement of the pin and slot type. In some embodiments, the object engaging device comprises at least one protrusion or pin configured to be received by a corresponding slot in a corresponding support.Thus, in some embodiments involving the placement of both a force sensor having a pivotal coupling portion for attaching an object engaging device to a support, and a stopper that prevents forward and backward movement of the object engaging device along the axial direction of the elongate object when engaged therewith, the substantially only movement left thereby is vertical movement up and down, and the pitch of that movement is limited by the vertical length inside the slot. This can enable a more accurate measurement of the force sensor to the downward force exerted on the elongate object when involved with or used with the present invention.

[0087] In alternative embodiments, the placement of the protrusion or pin into the slot may be reversed. In some alternative embodiments, the object engaging device comprises a slot configured to receive a pin or to receive a protrusion in the support. Having separate pins and slots in the support can assist in fitting the object engaging device onto the support. When the protrusions of the restraining means or stopper are fixed, they can still be positioned in place by friction fitting, particularly in embodiments where the engaging device or object engaging device includes plastic.

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

[0089] As used herein, the term "engaged" with respect to an engaged elongate object or engaged cable means that it is engaged during use when the elongate object or cable is engaged with an engaging means, an engaging device, or a cable shoe.

[0090] As used herein, the term "first direction" with respect to the movement of an engaging means or an object engaging device, etc., means movement backward and forward, or movement including backward movement and / or forward movement, or, when in use, means forward and backward along the axis of a long object when the long object is engaged with a device, system, or engaging device or engaging means. This also means movement backward and / or forward along the direction of travel when the present invention is in use.

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

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

[0093] As used herein, the terms "restraining means" and "restrainer" are used interchangeably and have the same meaning. A restrainer can, for example, comprise in part or in whole an arrangement of a pin and a slot, where one part can be on or attachable to an object mounting device or an object engaging device, and the other part can be on a support to which it is attached during use.

[0094] When used with respect to the movement of an engaging device, engaging means, or apparatus, etc., the term "second direction transverse or perpendicular to the first direction" means, for example, the vertical direction including up and down, up and down, or up or down in the vertical direction when in use and when oriented for use.

[0095] As used herein, the terms "upper" and "lower," and similar terms, are used to refer to the orientation of the object engagement device, apparatus, and system of the present invention when in use and when oriented for use. These terms are used to assist in explaining the present invention and are not necessarily limiting.

[0096] Here, preferred embodiments are described by way of example only and with reference to the following drawings, and are in no way limiting.

Brief Description of the Drawings

[0097]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0098] Referring to the figures, a cable burying vehicle 2 for burying a cable 4 in a trench 6 on the seabed 8 (FIG. 2) has a vehicle body 10, trench forming means in the form of a jet sword 12 mounted on the vehicle body 10, and moving means 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 depressor 16 for inserting the cable 4 into the trench 6 is pivotally mounted on the vehicle body 10 and includes a support 18 that can be raised or lowered relative to the vehicle body 10 using actuator means in the form of a hydraulic actuator 20.

[0099] The depressor 16 includes an object engaging device in the form of a plurality of cable shoes 22 mounted on the lower part of the support 18. The cable shoe 22 has an object engaging means in the form of a cable shoe contact surface 24, which is positioned such that the cable shoe contact surface forms an arc, and the radius of the arc is greater than or equal to the allowable minimum bending radius of the cable 4. Each cable shoe contact surface 24 may be contoured to the minimum bending radius of the cable 4. The cable shoe 22 may be provided with proximity detecting means in the form of a proximity sensor 26 (FIG. 3) for detecting the presence of the cable 4. In this case, the cable shoe 22 is manufactured from a material that is not detected by the proximity sensor 26.

[0100] Each cable shoe 22 is mounted on the support 18 by force measuring means in the form of a shear pin load cell 28, and the rotation of each cable shoe 22 around the corresponding load cell 28 (equal to the movement of the cable shoe 22 relative to the support 18 in the axial direction of the cable 4) is restricted by restraining means in the form of one or more positioning pins 30 positioned approximately in line with the corresponding cable shoe contact surface 24. The clearance between the positioning pin 30 and the cable shoe 22 or the support 18 allows limited movement of the cable shoe 22 in a second direction that is transverse or perpendicular to the first direction. As a result, the cable friction is exerted only by the positioning pin 30 and not by the load cell 28, and as a result, the load cell 28 receives substantially the only load in the direction of their respective shear planes, so that the true 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 or perpendicular to the axis of the cable 4, is measured.

[0101] Once attached, 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 cable contact and not to the contact force with the pure soil. The shoe proximity sensor 26 and the load cell 28 are monitored separately, so that the contact location is defined and the load pin force is measured at a specific location. This provides an indication in the form of a cable catenary throughout the laying process.

[0102] The radial load on the cable reduces the risk of damage to the cable 4 by reducing the weight of the depressor 16 underwater and, consequently, the cable contact force. This can be reduced by applying hydraulic pressure to the actuator 20 (typically, to the annular side surface of the lifting cylinder of the actuator 20). Thus, the depressor 16 only applies a limited downward force to the cable 4 but can still measure the cable burial depth.

[0103] Figures 5 and 6 show another embodiment of the cable shoe 22 of the present invention. As can be seen in this embodiment, the cable shoe 22 is positioned between two flanges 18a of the support 18. The flanges 18a of the support 18 include through holes 32 that can receive a force sensor, which is a load cell 28 in this embodiment. The flanges 18a of the support 18 also include slots 33 configured to receive pins 30. The pins 30 are received by the slots 33 and are configured to be releasably attached to the object engaging device / cable shoe 22. In this example, the cable shoe 22 includes a plastic material. In this example, the flanges 18a of the support 18 include plastic. Also shown is a proximity sensor 26 that can confirm the presence or absence of the cable 4 to ensure that the load / force reading of the load cell 28 is for the cable 4 rather than for other things such as soil. In this example, the proximity sensor 26 can detect the presence of metal in the area of the contact surface 24 of the cable shoe 22 and thus can detect a cable 4 including any metal. Therefore, the proximity sensor 26 can distinguish between the presence of a cable 4 including metal and the presence of other non-metallic things such as soil. The embodiment of the cable shoe 22 in Figures 5 and 6 can also be releasably attached or mounted to the support 18 by force measuring means, which is a shear pin load cell 28 in this example. The shear pin load cell 28 is received in a through hole 34 of the cable shoe 22. As can be seen by the dashed line, the axis of the through hole 34 of the cable shoe 22 is in a horizontal plane with corresponding holes in the flanges 18a of the support 18 such that the load cell 28 is received by the two corresponding holes of the support 18 and the through hole 34 of the cable shoe 22. The shear pin load cell 28 functions to attach the cable shoe 22 to the support 18 via the flanges 18a of the support 18. The support 18, when in use, is generally above the cable shoe and the cable, with the flanges 18a on the upper side of the cable shoe. In this embodiment, the load cell 28 acts as a pivotal coupling for attaching the cable shoe 22 to the support 18.With this attachment, only the cable shoe 22 can pivot backward and forward along the axis of the engaged cable 4 or along the direction of travel. However, this is prevented by the pin 30 and the corresponding slot 33 seen around the pin 30 in FIG. 6. The slot 33 is, in this embodiment, an opening in the support 18 or in the flange 18a of the support 18. The positioning pin 30 prevents the axial movement of the cable shoe 22, or in other words, prevents the cable shoe 22 from pivoting in the rearward and forward directions of the vehicle when the cable shoe 22 is in use. The positioning pin 30 can move upward or downward in the vertical direction within the slot 33. This allows the cable shoe 22 to be moved only in a vertical upward or downward movement when in use, and thus, the shear pin load cell 28 measures only the vertical load pressure on itself. The shear pin load cell 28 can monitor and measure the force exerted on itself. This is equal to or directly proportional to the force exerted on the elongate object or cable when engaged with the cable shoe. The support 18 in this embodiment is configured to have two holes 32 in a horizontal plane along the axis of the through-hole 34 of the cable shoe 22.

[0104] The present invention is described using the following non-exhaustive list of examples, which do not exclude or limit other examples and embodiments of the present invention.

[0105] (Example) (Example 1) An object engaging device for engaging an elongate object inserted into a trench, Object engaging means adapted to be mounted on a support and to engage an elongate object inserted into a trench, Restraining means for substantially preventing movement of the object engaging means relative to the support in a first direction as a result of movement of the object engaging means relative to the elongate object in the axial direction of the elongate object, Force measuring means for providing an output that depends on the force applied to the object engaging means in a second direction that is transverse or perpendicular to the first direction An object engaging device comprising

[0106] (Example 2) The device according to Example 1, wherein the object engaging means comprises an object engaging surface and the restraining means is positioned adjacent to the object engaging surface

[0107] (Example 3) The device according to Example 1 or 2, wherein the restraining means comprises at least one protrusion adapted to be positioned on one of the object engaging means and the support and adapted to engage with the other of the object engaging means and the support

[0108] (Example 4) The device according to any one of Examples 1 to 3, wherein the force measuring means comprises at least one load cell

[0109] (Example 5) The device according to any one of Examples 1 to 4, further comprising proximity detection means for detecting the proximity of a long object

[0110] (Example 6) An object insertion device for inserting a long object into a trench, comprising A support adapted to be mounted on a vehicle body of a vehicle and movable relative to the vehicle for inserting a long object into a trench, and At least one object engaging device according to any one of Examples 1 to 5 And a device comprising

[0111] (Example 7) The device according to Example 6, comprising a plurality of said object engaging devices

[0112] (Example 8) The device according to Example 6 or 7, further comprising actuator means for moving the support relative to the vehicle body

[0113] (Example 9) The support is a device according to any one of Examples 6 to 8, adapted to be pivotally mounted on the vehicle body.

[0114] (Example 10) A vehicle comprising a vehicle body and an object insertion device according to any one of Examples 6 to 8.

[0115] (Example 11) The vehicle according to Example 10, further comprising trench forming means.

[0116] (Example 12) The vehicle according to Example 10 or 11, further comprising moving means for moving the vehicle relative to the trench.

[0117] It is understood by those skilled in the art that the foregoing embodiments are described by way of example only and not in a limiting sense, and that various alternatives and modifications are possible without departing from the scope of the present disclosure as defined by the appended claims.

Explanation of Reference Numerals

[0118] 2 Cable burying vehicle 4 Cables 6 Trenches 8 Seabed 10 Vehicle body 12 Jet sword 14 Track 16 Depressor 18 Support 18a Flange 20 Hydraulic actuator 22 Cable shoe 24 Cable shoe contact surface 26 Proximity sensor 28 Shear pin load cell 30 Positioning pin 32 Through hole 33 Slot 34 Through hole

Claims

1. An object engaging device for engaging a long object inserted into a trench, comprising: Object engaging means configured to be mounted on a support and engageable with a long object inserted into a trench; Restraining means for preventing movement of the object engaging means relative to the support in a first direction; Force measuring means for measuring a force applied to the object engaging means in a second direction perpendicular to the first direction; An object engaging device comprising the above.

2. The device according to claim 1, wherein the object engaging means comprises an object engaging surface, and the restraining means is positioned adjacent to the object engaging surface.

3. The device according to claim 1 or 2, wherein the restraining means comprises at least one protrusion configured to be releasably attachable to one side of the object engaging means and receivable by a slot in the support.

4. The device according to any one of claims 1 to 3, wherein the force measuring means comprises at least one load cell.

5. The device according to any one of claims 1 to 4, further comprising proximity detecting means for detecting the proximity of the long object.

6. The device according to claim 4, wherein the load cell is configured to be receivable in a drilling hole of the object engaging means.

7. The device according to claim 4 or 6, wherein the load cell is configured to be receivable through two corresponding holes in the support.

8. The device according to claim 5, wherein the proximity detecting means comprises a metal detection sensor.

9. An object insertion system for inserting a long object into a trench, comprising: A support configured to be mounted on a vehicle body of a vehicle and movable relative to the vehicle for inserting a long object into a trench; At least one object engaging device according to any one of claims 1 to 8, claim 17, or claim 18; An object insertion system comprising the above.

10. The device according to claim 9, comprising a plurality of the object engaging devices.

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

12. The device according to any one of claims 9 to 11, wherein the support is adapted to be pivotally mounted on 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 according to claim 13, further comprising trench forming means.

15. The vehicle according to claim 13 or 14, further comprising moving means for moving the vehicle relative to the trench.

16. A method for measuring a force exerted on an elongate object lowered to the seabed, the method comprising positioning an elongate object lowered to the seabed under an object engaging device according to any one of claims 1 to 8, claim 17, claim 18.

17. The first direction is a rearward or forward direction along the longitudinal axis of the elongate object when engaged with the engaging device or object engage, or is the direction of travel during use, the device according to any one of claims 1 to 8.

18. The second direction is a vertical direction upward or downward, the device according to any one of claims 1 to 8. ​

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