Fifth wheel coupling load measurement system

Abstract

A fifth-wheel load measurement system for sensing unbalanced loads between a prime mover and a trailer comprising: a body; a king pin adapted for coupling to a fifth wheel; and at least two sensors configured for measuring relative motion of the body in response to a force applied through the king pin.

Description

FIFTH WHEEL COUPLING LOAD MEASUREMENT SYSTEMField of the Invention

[0001] The present invention relates to load measurement systems and in particular to load measurement systems for the movement of cargo, goods and / or raw materials by way of haulage.

[0002] The invention has been developed primarily for use in methods and systems for load measurement systems for prime mover and trailer configurations coupled together by a fifth wheel coupling mechanism and will be described hereinafter with reference to this application . However, it will be appreciated that the invention is not limited to this particular field of use.Background

[0003] Any discussion of the background art throughout the specification should in no way be considered as an admission that such background art forms part of the common general knowledge in Australia or worldwide as at the priority date of the present application.

[0004] All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference, which means that it should be read and considered by the reader as part of this text. That the document, reference, patent application or patent cited in this text is not repeated in this text is merely for reasons of conciseness.

[0005] As is well known, and as shown in Figures 1 A and 1 B a prime mover (also known as a towing truck or tractor) 1 is connected to one or more towed trailers 3 by a fifth wheel connection 5. The fifth wheel coupling 5 typically consists of two components:(a) a kingpin, typically a steel pin with a diameter of 2 or 3.5 inches (50.8 or 88.9 mm) that extends from the bottom surface of the trailer, close to the front; and(b) a fifth wheel, which is a horseshoe-shaped coupling device installed on the back of the towing vehicle, the prime mover.

[0006] When connected such that the kingpin is connected to the centre of the fifth wheel, as the prime mover turns a downward-facing surface, the trailer rotates against an upward-facing surface of the fixed fifth wheel, which may or may not rotate depending on whether if it is a fixed-foot fifth wheel or load-stabilizing style (also known as a Ballrace-style) fifth wheel.

[0007] Historically, trailers designed to be towed by a prime mover are entirely freewheeling, with the only functional connection to the prime mover being low power electrical for trailer lighting and hydraulic or compression systems for trailer braking action.

[0008] With the decarbonisation movement becoming an area of focus in the transport and logistics industry, electric motors have started to be included in the trailer axles or wheel hubs themselves. Such trailer-mounted electric motors provide significant advantages including:■ providing additional motive force to take some load off the power requirements of the prime mover, thus allowing more efficient prime movers, including electric-drive prime movers; and■ recovery of lost energy through regenerative braking systems to capture kinetic energy from a decelerating trailer and transferring that energy to a storage battery for later use.

[0009] Even when being hauled by a combustion-engine prime mover, use of trailers with onboard electrical motors assist to improve overall fuel efficiency, vehicle stability and braking performance.

[0010] Recovered energy stored in the batteries can also be used to power additional functions, for example, the cooling compressor of a refrigerated trailer.

[0011] However, the addition of motors to each of the trailers in a single trailer or road-train configuration requires additional control mechanisms to ensure that the motors in the trailers are not working against the prime mover, for example still applying forward motive force after the driver in the prime mover has commenced a braking operation.

[0012] Further advantages of a load sensing system located at the fifth wheel coupling of a prime mover / trailer configuration as disclosed herein include:■ Detection of load forces between the prime mover and trailer or between adjacent trailers to provide inputs for stability data (i.e., yaw and lateral forces) which can be relayed to a control module which in turn can apply a motive force to the prime mover and / or trailer(s) to counteract the detected load forces for example in the prevention of “Jack-knifing” and trailer overturning scenarios during low speed manoeuvres by providing data that allows modulation of trailer brakes and / or Prime Mover engine drive.Providing the ability to apply braking systems in the event of detachment / uncoupling of the fifth wheel coupling.

[0013] The load variance between the prime mover 1 and the trailer 3 can be determined by measuring the load vectors applied by the trailer 3 onto the kingpin of the fifth wheel 3. Existing kingpin load measurement techniques are disclosed in prior art documents WO 2021 / 046091 toSensata Technologies, Inc. and WO 2022 / 074010 to Trailer Dynamics. The system of Sensata relies upon air gaps between the vertical (z-axis) load carrying faces which introduce uncertainty in the king pin load measurements performed by the apparats described therein. Similarly, the system of Trailer Dynamics describes a kingpin load measurement system utilising a method for inferring the deflection experienced by the kingpin. This method, however, is limited in that the kingpin deflection is dependent upon the method used in securing the kingpin to the fifth wheel coupling load plate, which are typically bolted together.

[0014] Further existing feedback systems using onboard electronics to infer the load relationship between the prime mover and each connected trailer are also both inaccurate and unreliable.Summary

[0015] Accordingly, there is a need for an improved sensor network to provide real-time feedback to the prime mover of the dynamic load between the prime mover and each connected trailer to provide a real-time feedback loop for efficient interactions between the prime mover and each connected trailer.

[0016] It is an object of the present invention to overcome or ameliorate at least one or more of the disadvantages of the prior art, or to provide a useful alternative.

[0017] According to a first aspect of the invention, there is provided a fifth-wheel load measurement system for sensing unbalanced loads between a prime mover and a trailer. The system may comprise a body. The system may further comprise a king pin adapted for coupling to a fifth wheel. The system may further comprise at least two sensors configured for measuring relative motion of the body in response to a force applied through the king pin.

[0018] According to a particular arrangement of the first aspect, there is provided a fifth wheel load measurement system for sensing unbalanced loads between a prime mover and a trailer comprising: a body; a king pin adapted for coupling to a fifth wheel; and at least two sensors configured for measuring relative motion of the body in response to a force applied through the king pin.

[0019] A first of the at least two sensors may be located forward of the king pin with respect to a direction of travel of the prime mover. A second of the at least two sensors may be located rearward of the king pin with respect to the direction of travel of the prime mover.

[0020] The at least two sensors may comprise either tension load cells or compression load cells. The at least two sensors may comprise at least two displacement sensors. The at least two sensors may comprise angular deflection sensors.

[0021] A load imbalance may be inferred by the amount of movement sensed by each of the at least two sensors. The sensors may be configured for measurement of a load imbalance less than a predetermined load. A load imbalance greater than the predetermined load may be decoupled from the body and the at least two sensors.

[0022] The body may comprise a load transfer plate coupled to the kingpin such that relative motion of the kingpin under unbalanced forces causes the load transfer plate to deflect proportional to the unbalanced force. The fifth-wheel load measurement system may comprise at least four sensors located at a respective vertices of the load transfer plate.

[0023] According to a second aspect of the present invention, there is provided a fifth -wheel load measurement system for sensing unbalanced loads between a prime mover and a trailer. The system may comprise a king pin adapted for coupling to a fifth wheel. The system may further comprise a load transfer shaft rigidly connected to the kingpin. The system may further comprise a load transfer plate rigidly connected to the load transfer shaft. The system may further comprise a plurality of load cells. Each load cell may include an actuator pin. The load cells may be located circumferentially about a periphery of the load transfer plate. The actuator pin of each load cell may be configured to contact and underside of the load transfer plate, such that angular deflection of the kingpin arising from a load imbalance between the prime mover and the trailer is translated to an angular rotation of the load transfer plate which is sensed by linear actuation of the actuator pin of each of the load cells.

[0024] According to a particular arrangement of the second aspect, there is provide a fifth -wheel load measurement system for sensing unbalanced loads between a prime mover and a trailer comprising: a king pin adapted for coupling to a fifth wheel; a load transfer shaft rigidly connected to the kingpin; a load transfer plate rigidly connected to the load transfer shaft; and a plurality of load cells, each including an actuator pin; wherein the load cells are located circumferentially about a periphery of the load transfer plate; and wherein the actuator pin of each load cell is configured to contact and underside of the load transfer plate, such that angular deflection of the kingpin arising from a load imbalance between the prime mover and the trailer is translated to an angular rotation of the load transfer plate which is sensed by linear actuation of the actuator pin of each of the load cells.

[0025] A load imbalance may be inferred by the amount of movement sensed by each of the plurality of load cells.

[0026] Each of the load cells may be configured at an angle to the vertical axis of the respective load cell actuator pin.

[0027] The coupling shaft may be contained within and rigidly connected to a spherical load transfer bearing having a centrally located pivot point.

[0028] The spherical load transfer bearing may be located in a housing of the fifth -wheel load measurement system.

[0029] An angled portion of an underside of the load transfer plate may be coincident with a ray originating from the pivot point.

[0030] The actuator pin of the load cell may be aligned normal to the angled portion of the underside of the load transfer plate such that the load cell is aligned normal to the ray originating from the pivot point of the load transfer bearing.

[0031] The load transfer plate may be circular. The fifth-wheel load measurement system may comprise at least three load cells located equi-circumferentially about the periphery of the load transfer plate.

[0032] The load transfer plate may be a square plate. The fifth -wheel load measurement system may comprise at least four load cells located equi-circumferentially about the periphery at each vertex of the load transfer plate.

[0033] The fifth-wheel load measurement system may further comprise a brace. The brace may be rigidly connected between the skid plate and the underside of the load transfer plate. The brace may be configured to prevent rotation of the load transfer plate.

[0034] The load transfer plate may be a hexagonal plate. The fifth-wheel load measurement system may comprise at least six load cells located equi-circumferentially about the periphery at each vertex of the load transfer plate. The system may further comprise a brace to prevent rotation of the hexagonal load transfer plate.

[0035] The load transfer plate may be a dodecagonal plate, the fifth -wheel load measurement system comprising at least twelve load cells located equi-circumferentially about the periphery at each vertex of the load transfer plate. The system may further comprise a brace to prevent rotation of the dodecagonal load transfer plate.

[0036] The fifth-wheel load measurement system may further comprise a rigid base plate upon which the load measurement system is mounted such that no static vertical force is applied to the load cells.

[0037] According to a third aspect of the invention, there is provided a fifth wheel coupling load measurement system for sensing unbalanced loads between a prime mover and a trailer. The system may comprise a king pin adapted for coupling to a fifth wheel. The system may further comprise a load transfer shaft rigidly connected to the kingpin. The system may further comprise a load transfer plate rigidly connected to the load transfer shaft. The system may further comprise a plurality of load cells, each including an actuator pin. The load cells may be located circumferentially about a periphery of the load transfer plate. The actuator pin of each load cell may be configured to contact and underside of the load transfer plate. Angular deflection of the kingpin arising from a load imbalance between the prime mover and the trailer is translated to an angular rotation of the load transfer plate which is sensed by linear actuation of the actuator pin of each of the load cells.

[0038] According to a particular arrangement of the third aspect, there is provided a fifth wheel coupling load measurement system for sensing unbalanced loads between a prime mover and a trailer comprising: a king pin adapted for coupling to a fifth wheel; a load transfer shaft rigidly connected to the kingpin; a load transfer plate rigidly connected to the load transfer shaft; and a plurality of load cells, each including an actuator pin; wherein the load cells are located circumferentially about a periphery of the load transfer plate; and wherein the actuator pin of each load cell is configured to contact an underside of the load transfer plate, such that angular deflection of the kingpin arising from a load imbalance between the prime mover and the trailer is translated to an angular rotation of the load transfer plate which is sensed by linear actuation of the actuator pin of each of the load cells.

[0039] A load imbalance may be inferred by the amount of movement sensed by each of the plurality of load cells.

[0040] Each of the load cells may be configured at an angle to the vertical axis of the respective load cell actuator pin.

[0041] The coupling shaft may be contained within and rigidly connected to a spherical load transfer bearing having a centrally located pivot point.

[0042] The spherical load transfer bearing may be located in a housing of the fifth wheel coupling load measurement system.

[0043] An angled portion of an underside of the load transfer plate may be coincident with a ray originating from the pivot point.

[0044] The actuator pin of the load cell may be aligned normal to the angled portion of the underside of the load transfer plate such that the load cell is aligned normal to the ray originating from the pivot point of the load transfer bearing.

[0045] The load transfer plate may be circular, and the system may comprise at least three load cells located equi-circumferentially about the periphery of the load transfer plate.

[0046] The load transfer plate may be a square plate and the system may comprise at least four load cells located equi-circumferentially about the periphery at each vertex of the load transfer plate.

[0047] The system may further comprise a brace rigidly connected between the skid plate and the underside of the load transfer plate to prevent rotation of the load transfer plate.

[0048] The load transfer plate may be a hexagonal plate, and the system may comprise at least six load cells located equi-circumferentially about the periphery at each vertex of the load transfer plate. The system may further comprise a brace to prevent rotation of the hexagonal load transfer plate.

[0049] The load transfer plate may be a dodecagonal plate, and system may comprise at least twelve load cells located equi-circumferentially about the periphery at each vertex of the load transfer plate The system may further comprise a brace to prevent rotation of the dodecagonal load transfer plate.

[0050] The system may further comprise a rigid base plate upon which the load measurement system may be mounted such that no static vertical force is applied to the load cells.Brief Description of the Drawings

[0051] Notwithstanding any other forms which may fall within the scope of the present invention, a preferred embodiment / preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:Figures 1 A and 1 B show a prime mover and trailer configurations coupled together via a fifth wheel coupling mechanism;Figures 2A and 2B show perspective views of a fifth wheel coupling load measurement system in accordance with an embodiment of the present invention ;Figure 2C shows a top view of the fifth wheel coupling load measurement system of Figure 1 ;Figure 3 shows a cross section of the fifth wheel coupling load measurement system of Figure 2A through section A-A of Figure 2C;Figures 4A and 4B show an alternate embodiment of the fifth wheel coupling load measurement system of Figure 2A;Figure 4C shows a cross section of the fifth wheel coupling load measurement system of Figure 4A through section B-B of Figure 4B;Figure 5A shows an alternate embodiment of the fifth wheel coupling load measurement system of Figure 2A;Figure 5B shows a cross section of the fifth wheel coupling load measurement system of Figure 5A through section C-C;Figures 6A to 6B show a further embodiment of the fifth wheel coupling load measurement system of Figure 2A; andFigures 7A to 7B show a further embodiment of the fifth wheel coupling load measurement system of Figure 2A.

[0052] In the drawings, like structures are referred to by like numerals throughout the several views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the present invention.Detailed Description

[0053] Figure 1A shows a depiction of a prime mover 1 and trailer 3 configuration coupled together by a fifth wheel coupling 5, wherein one or more of each axle of trailer 3 includes an axle / or hub motor 7. Figure 1 B shows a depiction of a B-Double combination [configuration including a prime mover 1 and a plurality of trailers 3 each coupled together by a respective fifth wheel coupling 5, wherein one or more of each axle of each trailer 3 includes an axle / or hub motor 7. The fifth wheel coupling load measurement system 100 as disclosed herein is also applicable to multiple trailer road train configurations including a prime mover 1 and multiple trailers 3 each connected to the adjacent trailer 3 by a fifth wheel coupling 5 as would be readily appreciated by the skilled addressee.

[0054] Figures 2A and 2B show a fifth wheel coupling load measurement system 100 comprising a trailer chassis 101 comprising a rigid base plate (skid plate) 103 connected to a trailer chassis 101 and a kingpin 105 connected to a first embodiment 107A of a load transfer plate 107.

[0055] A plurality of primary load cells 110 are located circumferentially around load transfer plate 107A and connected to both the load transfer plate 107A and skid plate 103. Fifth wheel coupling load measurement system 100 is mounted on rigid base plate 103 to ensure that no static vertical force is applied to the load cells.

[0056] In use, kingpin 105 is engaged with a fifth wheel assembly of the prime mover 1 such that any imbalance in load between the trailer 3 and the prime mover 1 is transferred through kingpin 105 to load transfer plate 107A in the form of an angular deflection of the kingpin 105 which is magnified by the load transfer plate 107A. The angular deflection of the load transfer plate is detected by the plurality of load cells 110 and signal measurements of the magnitude of the angular deflection sensed by load cells 110 is communicated to an electronic control module (not shown) in trailer 3. The signal measurements may also optionally be relayed to a further control module located in the prime mover 1 as necessary. The electronic control module in the trailer 3 interprets the deflection signals from load transfer plate 107A to determine the magnitude and direction of the load imbalance, for example whether the trailer 3 is either leading (pushing) the prime mover 1 or the trailer 3 is either lagging (pulling) the prime mover 1 . In the event the control module detects that the trailer 3 is pushing the prime mover 1 , for example, travelling down a descent, or when the driver applies the brakes to the prime mover but the braking signal has not yet been received by the trailer braking mechanism(s), the control module may send a signal to the one or more onboard trailer motors to either cease forward motive force and / or switch to a regenerative energy recapture mode so that the trailer motor(s) are not opposing the braking signals activated by the prime mover 1 .

[0057] In the reverse situation, where the control module detects that the trailer 3 is lagging the prime mover 1 , for example, the prime mover is ascending or accelerating, the control module may send a signal to the one or more onboard trailer motors to apply or increase the forward motive force applied to the trailer axle(s) to assist the prime mover for more efficient forward motion thus providing significant efficiency advantages to the prime mover 1 .

[0058] Referring now to Figure s, to transfer the forces acting on the kingpin 105 to a first embodiment 107A of load transfer plate 107, kingpin 105 is connected to a load transfer coupling shaft 120 which extends through skid plate 103 and is contained by a spherical load transfer bearing 121 captured in a housing 123. Load transfer plate 107A is also rigidly connected to coupling shaft 120 such that an angular deflection of kingpin 105 caused by any load imbalancebetween prime mover 1 and trailer 3 are transferred in a bearing arc 109 through spherical bearing 121 about pivot point 125 which is reflected in a corresponding angular deflection in load transfer plate 107A about the bearing arc 109. This angular deflection in load transfer plate 107A is sensed by primary load cells 110 mounted to skid plate 103 concentrically around the periphery of the load transfer plate 107A.

[0059] The rigid assembly comprising kingpin 105, load transfer coupling shaft 120, load transfer plate 107A and spherical bearing 121 rotate about a pivot point 125 located centrally to spherical bearing 121. In particular arrangements, as depicted in Figure 3, the periphery of the load transfer plate 107A is angled upwards such that the underside 108 of load transfer plate 107A is coincident with a ray 126 originating from pivot point 125. In this configuration, load cell 110 are mounted at an angle away from the vertical and thus the point of contact 114 between load transfer plate 107A and load cells 110 is aligned with pivot point 125. This ensures that the most accurate deflection (i.e., full deflection without friction effects on the actuator pin 112 of load cell 110) of the rigid assembly is transferred directly to load cells 110. In this embodiment, the load cells 110 are mounted to skid plate 103 with angular mounting plates 113 such that load cells 110 are aligned normally to the underside surface 108 of the load transfer plate 107A, and thus are aligned normally to ray 126 extending from the pivot point 125 to the contact point 114 between actuator pin 112 of load cell 110 and underside surface 108 of load transfer plate 107A to ensure that the load cells 110 are. aligned with the bearing arc 109 to eliminate side loading of the load cells 110 during operation. In alternate embodiments (not shown), the load cells 110 may be mounted to skid plate 103 such that the actuator pin 112 is aligned perpendicularly (i.e., vertically) with respect to skid plate 103.

[0060] In particular arrangements of load measurement system 100, at least 3 primary load cells 110 are mounted equi-circumferentially (circumferentially equally spaced) around the periphery of the load transfer plate 107A, to permit detection of any angular deflection (about 360°) of the kingpin 105 i.e., both forward and backward deflection indicating the trailer 3 respectively either pushing or pulling on the prime mover 1 or lateral deflections of the kingpin 105 resulting from lateral or sideways forces on the trailer 3 indicating uneven terrain or possible “jack-knifing” of the trailer 3 with respect to the prime mover 1 .

[0061] In other arrangements more load cells 110 may be arranged around the load transfer plate, for example 4, 6, 8, 10 cells arranged equi-circumferentially about the load transfer plate 107A.

[0062] In further arrangements, secondary load cells 111 may also be connected to the load transfer plate 107A interspersed between primary load cells 110 whereby primary and secondary load cells are respectively configured, for example, coarse, and fine angular deflection sensingfor improved precision in accurately measuring the load on kingpin 105 from trailer 3. In particular arrangements, primary load cells 110 may be rated for about 10 tonne of applied load capacity and secondary load cells, where provided, may be rated for about 5 tonne of applied load capacity. However, differently rated primary and secondary load cell ratings may be provided in accordance with requirements as would be readily appreciated by the skilled addressee. In a particular arrangement, the 10-tonne capacity primary load cells may provide a load resolution of about 0.005 tonne and the 5-tonne capacity primary load cells may provide a load resolution of about 0.0001 tonne.

[0063] Depending upon the type of load cells used in the system, primary load cells 110 (and, where present, secondary load cells 111 ) are preferably preloaded during installation to mid-compression to permit sensing of both positive and negative deflections and to allow equal sensor measurement in both compression and decompression through all ranges of load transfer for greater precision and accuracy in sensing the loads transferred to the transfer plate 107A from kingpin 105.

[0064] In particular arrangements, such as those depicted in Figures 4A, 4B and 4C, load transfer plate 107A is configured such that is unable to rotate by way of lateral bracing. In alternate embodiments, such as those depicted in Figures 2A, 2B, 2C and 3, the load transfer plate may be permitted to rotate freely which would permit reduced scheduled calibration requirements on load cells 110. Using a load transfer plate which is able to freely rotate about the vertical aspect of the provides significant advantages over a fixed load transfer plate including improved bearing wear characteristics compared with embodiments where the load transfer plate is fixed in place or braced, however, the freely rotating load transfer plate is expected to require more frequent calibration compared with the rigid or square plate. A further advantage of the freely rotating arrangement of the load transfer plate, is that it is generally more cost effective to manufacture than a rigid or braced load transfer plate and provides for improved bearing wear characteristics which has advantages for less ongoing maintenance and a longer life than rigid embodiments. On the contrary, a rigid or braced load transfer plate embodiment has the advantage or requiring less frequent calibration service intervals over freely rotating embodiments. The selection between either a freely rotating and a rigid or braced embodiment will depend on the particular environmental conditions under which the system is planned to operate.

[0065] A further embodiment of a fifth wheel coupling load transfer system 200 is depicted in Figures 4A and 4B where like-reference numerals are indicative of like-features as described above. In this embodiment, a further embodiment 107B of load transfer plate 107 is provided a square plate and load transfer cells 110 are located equi-circumferentially around load transferplate 107B preferably at each corner of square load transfer plate 107B to provide maximum deflection of load cells 110 about bearing arc 109.

[0066] Figure 4C shows a cross section of second embodiment 200 along section B-B of Figure 4B. As described above, kingpin 105 is rigidly connected to load transfer coupling shaft 120 and load transfer plate 107B via spherical load transfer bearing 121 captured within housing 123. Load transfer bearing translates deflections of kingpin 105 to load transfer plate 107B about bearing arc 109. Similarly, as described above with reference to the embodiment of Figure 2C, load cells 110 are mounted on angled mounting plates 113 such that the load cells are aligned normally to ray 126 extending from the pivot point 125 to the contact point 114 between load cell 110 and underside surface 108 of load transfer plate 107B. In the present arrangement, the outer periphery of load transfer plate 107B is not aligned with ray 126 as is load transfer plate 107A, therefore, load transfer plate 107B includes a recess and / or cutaway portion configured to receive actuator pin 112 of load transfer cell such that the actuator pin 112 is normal to ray 126, again to eliminate side loading of the load cells 110 during operation. In alternate embodiments such as depicted in Figures 5A and 5B, the load cells 110 may be mounted vertically on the skid plate 103.

[0067] A further embodiment of a fifth wheel coupling load measurement system 300 is depicted in Figure 5A where like-reference numerals are indicative of like-features as described above. In this embodiment, a further embodiment 107C of load transfer plate 107 is provided as a square plate and load transfer cells 110 are located equi-circumferentially around load transfer plate 107C preferably at each corner of square load transfer plate 107C to provide maximum deflection of load cells 110 about bearing arc 109. Fifth wheel coupling load measurement system 300 includes a brace 501 connected between the skid plate 103 and load transfer plate 107C to prevent load transfer plate 107C from rotating in the plane of skid plate 103 which prevents unwanted lateral stresses being applied to each of the load cells 110.

[0068] Figure 5B shows a cross section of second embodiment 200 along section C-C of Figure 5A. As described above, kingpin 105 is rigidly connected to load transfer coupling shaft 120 and load transfer plate 107C via spherical load transfer bearing 121 captured within housing 123. The load transfer bearing 121 translates forces acting on the kingpin 105 to load transfer plate 107C about bearing arc 109. Such forces acting on the kingpin 105 cause deflection of the kingpin from the vertical plane which is translated to the skid plate as a rotation of the load transfer plate, which is rigidly fixed to the and load transfer plate 107C extending from the pivot point 125 to the contact point 114 between load cell 110 and underside surface 108 of load transfer plate 107B. In the present arrangement, the outer periphery of load transfer plate 107B is not aligned with a ray extending from pivot point 125 (as is the case in Figure 3), therefore, load transfer plate107B includes a recess and / or cutaway portion configured to receive actuator pin 112 of load transfer cell.

[0069] In further arrangements, load transfer plate 107 (including load transfer plate embodiments 107A / 107B / 107C) may alternatively be shaped as a regular polygon with load cells located at each vertex of the polygon. For example, load transfer plate may be provided in a hexagonal configuration with 6 primary load cells located at each of the 6 vertices of the load transfer plate. Secondary load cells 111 may optionally be located intermediate the primary load cells 110 at a location bisecting each of the sides of hexagonal load transfer plate. In a further example, load transfer plate may be provided in a dodecagonal (12-sided) configuration with 12 primary load cells located at each of the 12 vertices of the load transfer plate. Again, secondary load cells 111 may optionally be located intermediate the primary load cells 110 at a location bisecting each of the sides of dodecagonal load transfer plate. Octagonal (8-sided), decagonal (10-sided), hexadecagon (16-sided) load transfer plates (or other n-sided polygonal configurations) may also be considered in accordance with requirements with corresponding number of primary load cells and optional secondary load cells as would be appreciated by the skilled addressee.

[0070] In each embodiment disclosed above, the size of the load transfer plate (i.e., the linear distance from the centre of the load transfer plate to the peripheral edge is preferably configured to be as large as possible with respect to the trailer chassis 101 . A larger radial distance from the centre of the load transfer plate to the peripheral edge where the load cells are engaged with the load transfer plate provides a larger lever arm by which the angular deflection of the load transfer coupling shaft 120 from the kingpin 105 the 10-tonne capacity primary load cells may provide a load resolution of 0.005 tonne translates to a larger linear movement at the edge where the load cells are engaged. This then provides for a larger movement of the actuator pin such that the load cell is able to provide more sensitive data of the unbalanced loads transmitted from trailer 3 to the prime mover 1 through the kingpin 105. As would be appreciated, as the size of the load transfer plate increases, the material from which it is formed must be stiffer to accurately translate the load forces on the load transfer coupling shaft 120 to the load cells 110 without bending. However, a larger load transfer plate provides the advantage that smaller capacity load cells can be used while maintaining equivalent load measurement resolution compared with a smaller load transfer plate and larger load capacity, and more expensive, load cells 110.

[0071] A further embodiment of a fifth wheel coupling load measurement system 400 is depicted in Figure 6A where like-reference numerals are indicative of like-features as described above.

[0072] In this embodiment, fifth wheel coupling load measurement system 400 is configured to utilise only two load cells 410 located either side of axis 405 about which body 401 rotates underaccelerating or decelerating loads on prime mover 1 and trailer 3, due to loads transferred through king pin 105. Fifth wheel coupling load measurement system 400 is configured such that load cells 410 are located forward and aft of king pin 105 with respect to the prime mover 1 and trailer 3. In this dual-sensor configuration the fifth wheel coupling load measurement system 400 measures forces in the pitch plane of the prime mover 1 such as acceleration and braking in the direction of travel of the prime mover 1 and trailer 3. System 400 is analogous to system 100 in that skid plate 103 is functionally equivalent to mounting plate 402 and load transfer plate 107 is functionally equivalent to body 401 wherein load cells 410 connect between body 401 and mounting plate 402 and measure relative rotation of body 401 with respect to mounting plate 42 about axis 405.

[0073] Figures 6B and 6D respectively show side and end views of system 400. Figure 6C shows a cross section of system 400 along line D-D of Figure 6D showing the load cells 410. Figure 6E shows a cross section of system 400 along line C-C of Figure 6B. In this particular embodiment, load cells 410 are depicted as tension load cells.

[0074] Kingpin 105 of system 400 is rigidly connected to body 401 which in turn is rigidly connected to one end of load cells 410 via mounting plate 402 such that deflection of kingpin 105 in the pitch plane is transferred through body 401 about axis 405 to the load cells 410 as a compression / tension force on the respective load cells 410. The compressive / tensile forces imparted to load cells 410 are measured and any imbalance in load between the trailer 3 and the prime mover 1 is transferred through kingpin 105 to load cells 410 in the form of an angular deflection of the kingpin 105 which is magnified by body 401 . The angular deflection of the kingpin 105 is detected by the load cells 410 and signal measurements of the magnitude of the angular deflection sensed by load cells 410 is communicated to an electronic control module (not shown) in trailer 3. The signal measurements may also optionally be relayed to a further control module located in the prime mover 3 as necessary. The electronic control module in the trailer 3 interprets the deflection signals from load cell 410 to determine the magnitude and direction of the load imbalance, for example whether the trailer 3 is either leading (pushing) the prime mover 1 or the trailer 3 is either lagging (pulling) the prime mover 1 . As discussed above, the electronic control module may provide a control signal to one or more motors to either increase or decrease the forward motive force provided to trailer 3 in order to balance the load on prime mover 1 .

[0075] A further embodiment of a fifth wheel coupling load measurement system 500 is depicted in Figure 7A where like-reference numerals are indicative of like-features as described above. In this embodiment, fifth wheel coupling load measurement system 500 is configured to utilise only two load cells 510 located either side of axis 505, about which body 401 rotates under accelerating or decelerating loads on prime mover 1 and trailer 3, due to loads transferred through king pin 105. Fifth wheel coupling load measurement system 500 is configured such that load cells 510are located forward and aft of king pin 105 with respect to the prime mover 1 and trailer 3. Again, in this dual-sensor configuration, the fifth wheel coupling load measurement system 500 measures forces in the pitch plane of the prime mover 1 such as acceleration and braking in the direction of travel of the prime mover 1 and trailer 3. System 500 is analogous to system 100 in that skid plate 103 is functionally equivalent to mounting plate 502 and load transfer plate 107 is functionally equivalent to body 501 wherein load cells 510 connect between body 501 and mounting plate 502 and measure relative rotation of body 501 with respect to mounting plate 42 about axis 505.

[0076] Figures 7B and 7D respectively show side and end views of system 500. Figure 7C shows a cross section of system 500 along line F-F of Figure 7D showing the load cells 510. Figure 6E shows a cross section of system 500 along line E-E. In this particular embodiment, load cells 510 are depicted as compression load cells.

[0077] Kingpin 105 of system 500 is rigidly connected to body 501 which in turn is rigidly connected to one end of load cells 510 via mounting plate 502 such that deflection of kingpin 105 in the pitch plane is transferred through body 501 to the load cells as a compression / tension force on the respective load cells 510. The compressive / tensile forces imparted to load cells 510 are measured and any imbalance in load between the trailer 3 and the prime mover 1 is transferred through kingpin 105 to load cells 510 in the form of an angular deflection of the kingpin 105 which is magnified by body 501 . The angular deflection of the kingpin 105 is detected by the load cells 510 and signal measurements of the magnitude of the angular deflection sensed by load cells 510 is communicated to an electronic control module (not shown) in trailer 3. The signal measurements may also optionally be relayed to a further control module located in the prime mover 3 as necessary. The electronic control module in the trailer 3 interprets the deflection signals from load cell 510 to determine the magnitude and direction of the load imbalance, for example whether the trailer 3 is either leading (pushing) the prime mover 1 or the trailer 3 is either lagging (pulling) the prime mover 1. As discussed above, the electronic control module may provide a control signal to one or more motors to either increase or decrease the forward motive force provided to trailer 3 in order to balance the load on prime mover 1 , thus providing significant efficiency advantages to the prime mover 1 .

[0078] In each of the embodiments of the fifth wheel coupling load measurement system described herein, the load cells 110, 111 , 410, 510 may be selected to be compression and / or tension load cells. These type of load cells have the advantage that they do not require preloading of the cell to a preset zero load which can deform the supporting structure of the systems disclosed herein (such as the load transfer plate described above). Such fixed load cells are further advantageous as they allow for load cell failure redundancy and the determination of azero-load point is improved since the load cells are then equally opposed, which is not the case with unfixed (preloaded) load cells.

[0079] In further embodiments, the load cells described herein, e.g., load cells 110, 111 , 410, 510 , may be replaced by, or supplemented with alternative sensor types. For example, additional sensor types which may be used either instead of, or in conjunction with, the compression / tension - type load cells, may include one or more linear position or displacement or angular sensors which may be configured to directly determine the amount of pivoting movement and / or deflection of a component of the fifth wheel coupling load measurement system such as movement / deflection of a component comprising either the load transfer plate 107A, 107B, 107C or the body 401 , 501 as described above in accordance with embodiments of the invention. Suitable position and / or displacement and or angular sensors would be readily appreciated by the skilled person in the art and may, for example, include an optical position / displacement measurement system.

[0080] In each of the embodiments of the fifth wheel coupling load measurement system described herein, the load cells may be configured for measurement of load imbalances within a predetermined range. For example, the load cells may be specifically configured to only measure the load imbalance in a predetermined range which could be a smaller range of load which the load cells may be capable of measuring. Loads experienced by the load cells above a further predetermined load may be decoupled from the load measurement system for independent action. For example, in a particular example arrangement, the predetermined load range may be selected to be of the order of a range between about 100 kg to 1 .5 tonnes. In this example, any load imbalances greater than the predetermined range, e.g., about 1 .5 tonnes, may be diverted away from the load cells and an overload signal may be communicated to the control module. This allows for selection of load cells which have greater sensitivity and / or accuracy in the narrower range of interest and prevents exposure of the load cells to excessive forces which could significantly degrade the life of the load cell.

[0081] In further arrangements of the fifth wheel coupling load measurement system the load measurement system ad adapted for relative engagement with a kingpin such that the system may be able to readily be attached to and removed from a kingpin associated with a fifth wheel coupling system. This allows a standard, approved, replaceable kingpin to be attached or removed by any qualified and capable person with interference with the sensing assembly.Scope of Invention

[0082] Thus, while there has been described what are believed to be the preferred arrangements of the invention, those skilled in the art will recognize that other and furthermodifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention . Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[0083] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.Industrial Applicability

[0084] It will be appreciated that the methods / apparatus / devices / systems described / illustrated above at least substantially provide a fifth wheel coupling load measurement system.

[0085] The fifth wheel coupling load measurement system described herein, and / or shown in the drawings, are presented by way of example only and are not limiting as to the scope of the invention. Unless otherwise specifically stated, individual aspects and components of the system may be modified, or may have been substituted therefore known equivalents, or as yet unknown substitutes such as may be developed in the future, or such as may be found to be acceptable substitutes in the future. The fifth wheel coupling load measurement system may also be modified for a variety of applications while remaining within the scope and spirit of the claimed invention, since the range of potential applications is great, and since it is intended that the presently described fifth wheel coupling load measurement system be adaptable to many such variations.

[0086] Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention. The present invention is not to be limited in scope by any of the specific embodiments described herein. These embodiments are intended for the purpose of exemplification only. Functionally equivalent products, formulations and methods are clearly within the scope of the invention as described herein. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

[0087] Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some exampleembodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0088] Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

[0089] The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0090] Reference to positional descriptions and spatially relative terms), such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper” and the like, are to be taken in context of the embodiments depicted in the figures, and are not to be taken as limiting the invention to the literal interpretation of the term but rather as would be understood by the skilled addressee.

[0091] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first”, “second”, and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0092] It will be understood that when an element is referred to as being “on”, “engaged”, “connected” or “coupled” to another element / layer, it may be directly on, engaged, connected or coupled to the other element / layer or intervening elements / layers may be present. Other words used to describe the relationship between elements / layers should be interpreted in a like fashion ( e.g., ’’between”, “adjacent”). As used herein the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0093] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. The use of the singular includes the plural unless specifically stated otherwise. As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprise”, “comprises”, “comprising”, “including”, and “having”, or variations thereof are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:1 . A fifth-wheel load measurement system for sensing unbalanced loads between a prime mover and a trailer comprising: a body; a king pin adapted for coupling to a fifth wheel; and at least two sensors configured for measuring relative motion of the body in response to a force applied through the king pin.

2. A fifth-wheel load measurement system as claimed in Claim 1 wherein a first of the at least two sensors is located forward of the king pin with respect to a direction of travel of the prime mover, and a second of the at least two sensors is located rearward of the king pin with respect to the direction of travel of the prime mover.

3. A fifth-wheel load measurement system as claimed in either Claim 1 or Claim 2, wherein the at least two sensors comprise either tension load cells or compression load cells.

4. A fifth-wheel load measurement system as claimed in either Claim 1 or Claim 2, wherein the at least two sensors comprise at least two displacement sensors.

5. A fifth-wheel load measurement system as claimed in either Claim 1 or Claim 2, wherein the at least two sensors comprise angular deflection sensors.

6. A fifth-wheel load measurement system as claimed in any one of the preceding claims, wherein a load imbalance is inferred by the amount of movement sensed by each of the at least two sensors.

7. A fifth-wheel load measurement system as claimed in any one of the preceding claims: wherein the sensors are configured for measurement of a load imbalance less than a predetermined load; and wherein a load imbalance greater than the predetermined load is decoupled from the body and at least two sensors.

8. A fifth-wheel load measurement system as claimed in any one of the preceding claims, wherein the body comprises a load transfer plate coupled to the kingpin such that relative motion of the kingpin under unbalanced forces causes the load transfer plate to deflect proportional to the unbalanced force.

9. A fifth-wheel load measurement system as claimed in Claim 8, comprising at least four sensors located at a respective vertices of the load transfer plate.

10. A fifth-wheel load measurement system for sensing unbalanced loads between a prime mover and a trailer comprising: a king pin adapted for coupling to a fifth wheel; a load transfer shaft rigidly connected to the kingpin; a load transfer plate rigidly connected to the load transfer shaft; and a plurality of load cells, each including an actuator pin; wherein the load cells are located circumferentially about a periphery of the load transfer plate; and wherein the actuator pin of each load cell is configured to contact and underside of the load transfer plate, such that angular deflection of the kingpin arising from a load imbalance between the prime mover and the trailer is translated to an angular rotation of the load transfer plate which is sensed by linear actuation of the actuator pin of each of the load cells.1 1. A fifth-wheel load measurement system as claimed in Claim 1 , wherein a load imbalance is inferred by the amount of movement sensed by each of the plurality of load cells.

12. A fifth-wheel load measurement system as claimed in either Claim 10 or Claim 1 1 , wherein each of the load cells are configured at an angle to the vertical axis of the respective load cell actuator pin.

13. A fifth-wheel load measurement system as claimed in any one of the preceding claims, wherein the coupling shaft is contained within and rigidly connected to a spherical load transfer bearing having a centrally located pivot point.

14. A fifth-wheel load measurement system as claimed in Claim 13, wherein the spherical load transfer bearing is located in a housing of the fifth -wheel load measurement system.

15. A fifth-wheel load measurement system as claimed in either Claim 13 or Claim 14, wherein an angled portion of an underside of the load transfer plate is coincident with a ray originating from the pivot point.

16. A fifth-wheel load measurement system as claimed in Claim 15, wherein the actuator pin of the load cell is aligned normal to the angled portion of the underside of the load transfer plate such that the load cell is aligned normal to the ray originating from the pivot point of the load transfer bearing.

17. A fifth-wheel load measurement system as claimed in any one of the preceding claims, wherein the load transfer plate is circular, the fifth-wheel load measurement system comprising at least three load cells located equi-circumferentially about the periphery of the load transfer plate.

18. A fifth-wheel load measurement system as claimed in any one of the preceding claims, wherein the load transfer plate is a square plate, the fifth -wheel load measurement system comprising at least four load cells located equi-circumferentially about the periphery at each vertex of the load transfer plate.

19. A fifth-wheel load measurement system as claimed in any one of the preceding claims, further comprising a brace rigidly connected between the skid plate and the underside of the load transfer plate to prevent rotation of the load transfer plate.

20. A fifth-wheel load measurement system as claimed in any one of Claims 10 to 19, wherein the load transfer plate is a hexagonal plate, the fifth-wheel load measurement system comprising at least six load cells located equi-circumferentially about the periphery at each vertex of the load transfer plate.

21. A fifth-wheel load measurement system as claimed in Claim 20, further comprising a brace to prevent rotation of the hexagonal load transfer plate.

22. A fifth-wheel load measurement system as claimed in any one of Claims 10 to 19, wherein the load transfer plate is a dodecagonal plate, the fifth-wheel load measurement system comprising at least twelve load cells located equi-circumferentially about the periphery at each vertex of the load transfer plate.

23. A fifth-wheel load measurement system as claimed in Claim 22, further comprising a brace to prevent rotation of the dodecagonal load transfer plate.

24. A fifth-wheel load measurement system as claimed in any one of the preceding claims, further comprising a rigid base plate upon which the load measurement system is mounted such that no static vertical force is applied to the load cells.

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