WO2021046091A1

WO2021046091A1 - Kingpin load measurement method and apparatus

Info

Publication number: WO2021046091A1
Application number: PCT/US2020/049004
Authority: WO
Inventors: Robert Zwijze
Original assignee: Sensata Technologies, Inc.
Priority date: 2019-09-05
Filing date: 2020-09-02
Publication date: 2021-03-11

Abstract

A system for measuring a load force on a kingpin is provided on an undersurface of a trailer. The measuring system includes a first plate coupled to the undersurface of the trailer adjacent to, but not in contact with, the kingpin. A first plate gap is defined between the first plate and the undersurface of the trailer. A second plate is coupled to the first plate and a second plate gap is defined between the second plate and the undersurface of the trailer. Sensors are disposed in the second plate gap and coupled to one of the second plate and the undersurface of the trailer.

Description

Kingpin Load Measurement Method and Apparatus

Field of the Invention

[0001 ] This disclosure relates to systems and methods for measuring a load force on a trailer through a connection with a tractor.

Background

[0002] As is known, a fifth-wheel coupling links a semi-trailer to a towing truck or tractor vehicle. The fifth-wheel coupling usually consists of: a) a kingpin, often a 2-or-3 1/2-inch-diameter (50.8 or 88.9 mm) steel pin extending from the bottom surface of the semi-trailer, and near the front, of the semi-trailer; and b) a horseshoe-shaped coupling device, called a fifth wheel, provided on the rear of the towing vehicle, i.e., the tractor. The kingpin is coupled to the center of the fifth wheel so that when the truck turns, a downward-facing surface of the semi-trailer rotates against an upward-facing surface of the fixed fifth wheel, which does not rotate.

[0003] It is desirable for trailer companies to perform kingpin load measurements with a system that is connected to the trailer instead of connected to the truck or tractor vehicle. In this approach, the trailer system is independent of the tractor implementation and the total measured weight of the trailer can be transmitted, for example, to the cloud, via a telematics system of the trailer itself. Nevertheless, with large parasitic forces in the kingpin area of the tractor-trailer connection, designing a load measurement system connected to the trailer is a challenge.

[0004] What is needed, therefore, is an improved method and apparatus for measuring a kingpin load.

Summary

[0005] Disclosed herein are an apparatus and a method for measuring the load force on a trailer through the connection with a tractor. In one embodiment, the system includes a flexible plate attached to the underside of the trailer but separated therefrom by a gap. Forces from the fifth wheel of the tractor on the flexible plate are measurable with one or more load cells disposed between the underside of the trailer and an extension of the flexible plate.

[0006] According to one aspect of the present disclosure, a system for measuring a load force on a kingpin provided on an undersurface of a trailer comprises a first plate coupled to the undersurface of the trailer adjacent to, but not in contact with, the kingpin; a first plate gap defined between the first plate and the undersurface of the trailer; a second plate coupled to the first plate; a second plate gap defined between the second plate and the undersurface of the trailer; and at least one sensor disposed in the second plate gap and coupled to one of the second plate and the undersurface of the trailer.

[0007] In other embodiments, multiple sensors are disposed in the second gap and coupled to one of the second plate and the undersurface of the trailer.

[0008] In other embodiments, at least one sensor, or a plurality of sensors, disposed in the second gap, comprise load cell sensors.

[0009] In other embodiments, multiple sensors are arranged along an axis normal to the axis of the kingpin.

[0010] In other embodiments, a width of the second gap is greater than a width of the first gap.

[0011 ] According to another aspect of the present disclosure, a system for measuring a load force in a fifth-wheel coupling comprises: a trailer plate having a first surface; a kingpin provided on, and extending from, the trailer plate first surface; a flex plate provided on the trailer plate first surface and disposed about the kingpin; a first plate gap defined between the flex plate and the trailer plate first surface; an extension plate coupled to the flex plate and positioned such that a portion of the extension plate extends beyond the flex plate; a flex space defined between the portion of the extension plate that extends beyond the flex plate and the trailer plate first surface; and at least one load cell provided on the first surface of the trailer plate in the space defined between the extension plate and the trailer plate, wherein each at least one load cell is configured to detect a force in a direction parallel to a longitudinal axis of the kingpin. [0012] In other embodiments, the flex plate surrounds the kingpin. [0013] In other embodiments, an opening is defined in the flex plate, and the kingpin extends through the opening in the flex plate.

[0014] In other embodiments, the flex plate has a first end and a second end coupled to the trailer plate first surface.

[0015] In other embodiments, the extension plate extends from the first end of the flex plate, and the flex space is defined between a portion of the extension plate extending from the first end of the flex plate and the trailer plate first surface.

[0016] In another aspect of the present disclosure, an assembly kit for use with a fifth-wheel coupling system having a fifth-wheel mounted on a vehicle and a kingpin provided on, and extending from, a first surface of a trailer plate on a trailer, comprises: a flex plate, having an opening defined therein to accommodate and at least partially surround the kingpin without contacting the kingpin, configured to couple to the trailer plate first surface; an extension plate coupled to the flex plate such that a portion of the extension plate extends beyond a first end of the flex plate to define a flex space between the extension plate and the trailer plate first surface when the flex plate is coupled to the trailer plate first surface; and at least one load cell configured to be coupled between the trailer plate first surface and the extension plate in the defined flex space between the extension plate and the trailer plate first surface, wherein each load cell is configured to detect a force in a direction parallel to a longitudinal axis of the kingpin.

[0017] In another aspect of the present disclosure there is a system for measuring a load force in a fifth-wheel coupling, the system comprising: a trailer plate having a first surface; a kingpin provided on, and extending from, the trailer plate first surface; a flex plate provided on the trailer plate first surface and disposed about, but not in contact with, the kingpin; a plurality of bending beams extending from the flex plate and coupled to the trailer plate first surface; a beam gap defined between each bending beam of the plurality of bending beams and the trailer plate first surface; at least one displacement sensor provided in each bending beam of the plurality of bending beams; wherein each displacement sensor is configured to detect a force in a direction parallel to a longitudinal axis of the kingpin. [0018] In one aspect of the present disclosure, there is a system for measuring a load force in a fifth-wheel coupling system having a fifth-wheel mounted on a vehicle and a kingpin provided on, and extending from, a first surface of a trailer plate on a trailer, the system comprising: a flex plate, having an opening defined therein to accommodate and at least partially surround the kingpin without contacting the kingpin, configured to couple to the trailer plate first surface with a flex gap defined between the flex plate and the trailer plate first surface; a plurality of bending beams, extending from the flex plate, configured to couple to the trailer plate first surface with a beam gap defined between each bending beam of the plurality of bending beams and the trailer plate first surface; and at least one displacement sensor provided in each bending beam of the plurality of bending beams, wherein each displacement sensor is configured to detect a force in a direction parallel to a longitudinal axis of the kingpin.

[0019] In some embodiments, the plurality of bending beams comprises: a first pair of bending beams extending from a first side of the flex plate; and a second pair of bending beams extending from a second side of the flex plate, the second side of the flex plate different from the first side of the flex plate.

[0020] In some embodiments, the beams in the first pair of bending beams are parallel to one another.

[0021 ] In some embodiments, the first and second sides of the flex plate are opposite one another.

[0022] In some embodiments, at least one beam in the first pair of beams is co-linear with a beam in the second pair of beams.

[0023] It will be appreciated that many of the aspects, features and options described in view of the methods apply equally to the system. In addition, any one or more of the above aspects, features and options as described herein can be combined.

Description of the Drawings

[0024] Various aspects of the present disclosure are discussed herein with reference to the accompanying Figures. It will be appreciated that for simplicity and clarity of illustration, elements shown in the drawings have not necessarily been drawn accurately or to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity or several physical components may be included in one functional block or element. Further, where considered appropriate, reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. For purposes of clarity, however, not every component may be labeled in every drawing. The Figures are provided for the purposes of illustration and explanation and are not intended as a definition of the limits of the disclosure. In the Figures:

[0025] Figure 1 A is a bottom perspective schematic diagram illustrating an apparatus for measuring the load force on a trailer in accordance with an embodiment of the present disclosure;

[0026] Figure 1 B is a partial cross-sectional diagram of the apparatus of Figure 1 A from the direction represented by arrow A through the line V-V;

[0027] Figure 1 C is a partial cross-sectional diagram of the apparatus of Figure 1 A from the direction represented by arrow M through the line P-P;

[0028] Figure 1 D is a close-up of a portion of the apparatus of Figure 1 A;

[0029] Figure 1 E is a cross-sectional diagram of the relationship between a flex plate and a trailer plate in accordance with an aspect of the present disclosure;

[0030] Figure 2 is version of the apparatus of Figure 1 A, the fifth wheel not shown;

[0031] Figure 3 is a bottom perspective schematic diagram of the apparatus of Figure 1 A from the direction represented by arrow C;

[0032] Figure 4 is a perspective schematic diagram of the apparatus of Figure 3, the fifth wheel not shown;

[0033] Figure 5 is a bottom perspective diagram of an apparatus for measuring a force on a trailer in accordance with an embodiment of the present disclosure;

[0034] Figure 6 is a partial cross-sectional diagram of the apparatus of Figure 5 through the line H-H;

[0035] Figure 7 is a partial cross-sectional diagram of the apparatus of Figure 5 through the line J-J; [0036] Figure 8 is a bottom perspective schematic diagram illustrating an apparatus for measuring the load force on a trailer in accordance with an embodiment of the present disclosure (fifth wheel not shown);

[0037] Figure 9 is a perspective schematic diagram of the apparatus of Figure 8 with the fifth wheel shown;

[0038] Figure 10 is a partial cross-sectional diagram of the apparatus of Figure 9 through the line V’-V’ as viewed looking in the direction represented by arrow A’;

[0039] Figure 11 is a partial cross-sectional diagram of the apparatus of Figure 9 through the line P’-P’ as viewed looking in the direction represented by arrow M’;

[0040] Figure 12 is a close-up of a portion of the apparatus of Figure 9; and

[0041] Figure 13 is a cross-sectional diagram of a bottom perspective schematic diagram of the apparatus of Figure 9 from the direction represented by arrow C’.

Detailed Description

[0042] The present disclosure will be more completely understood through the following description, which should be read in conjunction with the drawings. In this description, like numbers refer to similar elements within various embodiments of the present disclosure. The skilled artisan will readily appreciate that the methods, apparatus and systems described herein are merely exemplary and that variations can be made without departing from the scope of the disclosure.

[0043] In the following detailed description, details are set forth in order to provide a thorough understanding of the aspects of the disclosure. It will be understood by those of ordinary skill in the art that these may be practiced without some of these specific details.

In other instances, well-known methods, procedures, components and structures may not have been described in detail so as not to obscure the aspects of the disclosure.

[0044] It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings as it is capable of implementations or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description only and should not be regarded as limiting.

[0045] Certain features, which are, for clarity, described in the context of separate implementations, may also be provided in combination in a single implementation. Conversely, various features, that are, for brevity, described in the context of a single implementation, may also be provided separately or in any suitable sub-combination.

[0046] Figures 1 A - 1 E and 2-4 illustrate a kingpin load measurement system 100 in accordance with an embodiment of the present disclosure. As shown in Figure 2, a bottom view of a trailer, the kingpin load measurement system 100 includes a kingpin 104 coupled to a trailer plate 108, i.e. , an underside surface of a trailer. A flex plate 112 is provided around the kingpin 104 and is also coupled or attached to the trailer plate 108. The flex plate 112 and the trailer plate 108 may each be made of high strength steel. The flex plate 112 does not contact the kingpin and, in one embodiment, may be provided with an opening 116 defined in the flex plate 112, for example, a hole, to accommodate the kingpin 104. Alternatively, the opening 116 can be a “notch” (not shown) in the flex plate 112.

[0047] In one aspect of the present disclosure, the flex plate 112 is generally rectangular with a longitudinal length L and a width W. An extension plate 120 is coupled to the flex plate 112 and extends from one end of the flex plate 112. One or more sensors, e.g., load cells 124, are disposed between the extension plate 120 and the trailer plate 108, as shown in Figure 4, and which will be described below in more detail. The flex plate 112 is coupled to the underside surface of the trailer, i.e., the trailer plate 108, but separated therefrom by a first gap or first space, gap1, as illustrated. The extension plate 120 is coupled to the flex plate 112, as illustrated, and separated from the undersurface of the trailer by a second gap or second space, gap2.

[0048] Referring now to Figure 1 A, the position of the flex plate 112 is chosen to at least partially surround the kingpin 104 and, in one embodiment of the present disclosure, fully surrounds the kingpin. In either arrangement, however, the flex plate 112 does not touch the kingpin 104 whether the flex plate 112 is fully or only partially surrounding the kingpin 104. In addition, the flex plate 112 is sized such that the width W is as large as a diameter of a fifth wheel 128 and has a length L at least as long, if not longer than, the fifth wheel diameter. As a result, any load forces from the fifth wheel 128 will be incident on the flex plate 112.

[0049] In operation, i.e. , when the kingpin 104 is coupled to the fifth wheel 128, the latter exerts a generally vertical force, with respect to gravity, on the flex plate 112. This force is located somewhere along a virtual line P-P between the pivots 132 of the fifth wheel 128. The flex plate 112, as set forth above, is fixed to the trailer plate 108 and is relatively stiff with respect to in-plane loads or forces, that is, forces along a direction J and a direction K, perpendicular to the direction J, as shown in Figure 1 A. The flex plate 112, however, is relatively more flexible for vertical loads or forces in the direction B, i.e., one of the directions of forces to be measured. In various embodiments, the flex plate 112 may have both ends fixed to the undersurface of the trailer, or only one end of the flex plate 112 at the first gap may be attached to the undersurface of the trailer in a pivoting manner as discussed below.

[0050] Assuming that the flex plate 112 has no bending stiffness, the load cells 124 carry half of the kingpin load. A location where the fifth wheel 128 is pressing on the flex plate 112 can, however, be changed by which a load ratio between the fifth wheel 128 and the load cells 124 is modified. In one embodiment, the flex plate 112 can be bolted down to the trailer plate 108 as shown in Figures 1A - 4.

[0051 ] In another embodiment of the present disclosure, a kingpin load measurement system 500 includes a flex plate 112 that is pivotably coupled to the trailer plate 108 as shown in Figures 5-7. The system 500 includes a pivot assembly that includes a pair of trailer plate pivot supports 510 attached to the trailer plate 108 and a pair of flex plate pivot supports 515 attached to the flex plate 112. In addition, an axle or rod 520 is provided through the trailer plate pivot supports 510 and the flex plate pivot supports 515 to allow the flex plate 112 to pivot as part of the pivot assembly. As a result, in the pivotably mounted arrangement of the system 500, the bending stiffness of the flex plate 112 is not influencing the total load measured in the load cells 124.

[0052] As shown in Figures 1 D, 3 and 4, one or more load cells 124 may be mounted on a load cell support member 136 that is attached to the trailer plate 108. When the fifth wheel exerts the force F on the kingpin 104 and the flex plate 112, the extension plate 120 will be displaced and will press against the load cell 124. Each load cell 124 is configured to measure an amount of force, along a direction parallel to the direction of force F, i.e., along a longitudinal axis of the kingpin 104, applied to it and will send a corresponding signal to a corresponding control system (not shown).

[0053] Depending on the materials used, a mismatch between the coefficient of thermal expansion (CTE) of the material of the trailer plate 108 and the CTE of the extension plate 120 may occur. In that event, side loads or side forces may appear on one or more of the load cells 124 leading to a measurement error. Further, the side load or forces can occur when the trailer plate 108 and the extension plate 120 have a same CTE but are at different temperatures. To compensate for this effect, due to either situation, a pivot can be coupled to the load cells to allow them to pivot, to some extent, sideways in order to negate the effects of CTE mismatch.

[0054] A kingpin load measurement system 800, in accordance with another aspect of the present disclosure, is shown in Figures 8-13. As shown in Figure 8, a bottom view of a trailer, the system 800 includes a kingpin 104 coupled to a trailer plate 108, i.e., an underside surface of a trailer, similar to the embodiments described above. A flex plate 804 is provided around the kingpin 104 and is also coupled or attached to the trailer plate 108. The flex plate 804 and the trailer plate 108 may each be made of high strength steel. The flex plate 804 does not contact the kingpin 104 and, in one embodiment, may be provided with an opening 816 defined in the flex plate 804, for example, a hole, to accommodate the kingpin 104, as shown in Figures 9, 10 and 11. Alternatively, the opening 816 can be a “notch” (not shown) in the flex plate 804.

[0055] Referring now to the embodiment shown in Figure 9, the flex plate 804 surrounds the kingpin 104 positioned within the opening 816 without, however, touching the kingpin 104. The flex plate 804, alternatively, can be positioned to at least partially surround the kingpin 104. Whether fully or only partially surrounding the kingpin 104, however, the flex plate 804 should not touch the kingpin 104. The flex plate 804 may be generally rectangular or square with a longitudinal length U and a width W. In addition, the flex plate 804 is sized such that the width W is as large as a diameter of a fifth wheel 128 and has a length U at least as long, if not longer than the fifth wheel diameter. As a result, load forces from the fifth wheel 128 will be incident on the flex plate 804. [0056] As shown in Figures 8 and 9, the flex plate 804 is connected to the trailer plate 108 by a plurality of bending beams 808 extending from the flex plate 804. In one embodiment, a first pair of bending beams 808-1 , 808-2 extends from a first side of the trailer plate 804 and are generally parallel to one another. Another, i.e. , a second, pair of bending beams 808-3, 808-4, generally parallel to one another, extends from a second side of the trailer plate 804, i.e., an opposite side to that of the first side, for a total of four bending beams 808. In the embodiment shown in Figures 8 and 9, opposing pairs of bending beams extend in opposite directions and are co-linear with the respective counterpart bending beam. Alternatively, although not shown, two additional pairs of bending beams 808 can be provided such that there is a pair of bending beams 808 extending from each side of the trailer plate 804, for a total of eight bending beams 808.

[0057] Each bending beam 808, in one embodiment, is coupled to the trailer plate 108 with a 4x4 arrangement of screw attachment points 812 (screws not shown). One of ordinary skill in the art will understand that other arrangements and/or types of connectors other than screws can be implemented.

[0058] One or more displacement sensors 820, e.g., each being an Eddy current sensor, are disposed in each bending beam 808. The flex plate 804 is coupled to the underside surface of the trailer, i.e., the trailer plate 108, but separated therefrom by a flex gap G, as illustrated. In addition, referring to Figures 10 and 12, each bending beam 808 is spaced from the trailer plate 108 by one or more shims 1204 placed near the screw attachment points 812 to define a beam gap.

[0059] In operation, i.e., when the kingpin 104 is coupled to the fifth wheel 128, the latter exerts a generally vertical force, with respect to gravity, on the flex plate 804. This force is located somewhere along a virtual line P-P between the pivots 132 of the fifth wheel 128. The flex plate 804, as set forth above, is fixed to the trailer plate 108 and is relatively stiff with respect to in-plane loads or forces, that is, forces along a direction J’ and a direction K’ perpendicular to the direction J’, as shown in Figure 9. The flex plate 804, however, is relatively more flexible for vertical loads or forces in the direction B’, i.e., one of the directions of forces to be measured. [0060] Any bending can be measured by the Eddy current sensors 820. Advantageously, upon an overload, the gap G closes and the measurement system is protected.

[0061 ] For purposes of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that scope of the concepts may include embodiments having combinations of all or some of the features described herein.

[0062] It will be obvious to those skilled in the art that modifications to the apparatus and process disclosed herein may occur, including substitution of various components or values, without parting from the scope of the disclosure as defined by the claims set forth herein.

What is claimed is:

Claims

1. A system for measuring a load force on a kingpin provided on an undersurface of a trailer, the system comprising: a first plate coupled to the undersurface of the trailer adjacent to, but not in contact with, the kingpin; a first plate gap defined between the first plate and the undersurface of the trailer; a second plate coupled to the first plate; a second plate gap defined between the second plate and the undersurface of the trailer; and at least one sensor disposed in the second plate gap and coupled to one of the second plate and the undersurface of the trailer.

2. The system of claim 1 , wherein the first plate surrounds the kingpin.

3. The system of claim 1 , further comprising: an opening defined in the first plate, wherein the kingpin extends through the opening in the first plate.

4. The system of claim 1 , wherein the at least one sensor comprises a load cell sensor.

5. The system of claim 4, wherein each at least one load cell sensor measures force in a direction parallel to a longitudinal axis of the kingpin.

6. The system of claim 5, wherein the at least one sensor comprises a plurality of load cell sensors.

7. The system of claim 1 , wherein the first plate has a first end and a second end coupled to the undersurface of the trailer.

8. The system of claim 7, wherein: the second plate extends from the first end of the first plate, wherein the second plate gap is defined between a portion of the second plate extending from the first end of the first plate and the trailer undersurface.

9. The system of claim 8, further comprising: a pivot assembly, coupled to the flex plate second end and the trailer undersurface, wherein he first plate is pivotably coupled to the trailer undersurface.

10. The system of claim 1 , wherein each of the first and second plates comprises high strength steel.

11. A system for measuring a load force in a fifth-wheel coupling, the system comprising: a trailer plate having a first surface; a kingpin provided on, and extending from, the trailer plate first surface; a flex plate provided on the trailer plate first surface and disposed about the kingpin, a first plate gap defined between the flex plate and the trailer plate first surface; an extension plate coupled to the flex plate and positioned such that a portion of the extension plate extends beyond the flex plate; a flex space defined between the portion of the extension plate that extends beyond the flex plate and the trailer plate first surface; and at least one load cell provided in the flex space and coupled to one of the second plate and the trailer plate first surface, wherein each at least one load cell is configured to detect a force in a direction parallel to a longitudinal axis of the kingpin.

12. The system of claim 11 , wherein the flex plate surrounds the kingpin.

13. The system of claim 11 , further comprising: an opening defined in the flex plate, wherein the kingpin extends through the opening in the flex plate.

14. The system of claim 11 , wherein the flex plate has a first end and a second end coupled to the trailer plate first surface.

15. The system of claim 14, wherein: the extension plate extends from the first end of the flex plate, and wherein the flex space is defined between a portion of the extension plate extending from the first end of the flex plate and the trailer plate first surface.

16. The system of claim 15, further comprising: a pivot assembly, coupled to the flex plate second end and the trailer plate first surface, wherein the flex plate is pivotably coupled to the trailer plate first surface.

17. The system of claim 11 , wherein each of the flex plate and the extension plate comprises high strength steel.

18. An assembly kit for use with a fifth-wheel coupling system having a fifth-wheel mounted on a vehicle and a kingpin provided on, and extending from, a first surface of a trailer plate on a trailer, the kit comprising: a flex plate, having an opening defined therein to accommodate and at least partially surround the kingpin without contacting the kingpin, configured to couple to the trailer plate first surface; an extension plate coupled to the flex plate such that a portion of the extension plate extends beyond a first end of the flex plate to define a flex space between the extension plate and the trailer plate first surface when the flex plate is coupled to the trailer plate first surface; and at least one load cell configured to be coupled between the trailer plate first surface and the extension plate in the defined flex space between the extension plate and the trailer plate first surface, wherein each load cell is configured to detect a force in a direction parallel to a longitudinal axis of the kingpin.

19. The assembly kit of claim 18, wherein the flex plate surrounds the kingpin.

20. The assembly kit of claim 18, wherein the flex plate further comprises: a second end configured to couple to the trailer plate first surface.

21. The assembly kit of claim 20, further comprising: a pivot assembly, coupled to the flex plate at the second end, configured to couple to the trailer plate first surface to pivotably couple the flex plate to the trailer plate.

22. A system for measuring a load force in a fifth-wheel coupling, the system comprising: a trailer plate having a first surface; a kingpin provided on, and extending from, the trailer plate first surface; a flex plate provided on the trailer plate first surface and disposed about, but not in contact with, the kingpin; a flex gap defined between the flex plate and the trailer plate first surface; a plurality of bending beams, extending from the flex plate, coupled to the trailer plate first surface; a beam gap defined between each bending beam of the plurality of bending beams and the trailer plate first surface; and at least one displacement sensor provided in each bending beam of the plurality of bending beams, wherein each displacement sensor is configured to detect a force in a direction parallel to a longitudinal axis of the kingpin.

23. The system of claim 22, wherein the plurality of bending beams comprises: a first pair of bending beams extending from a first side of the flex plate; and a second pair of bending beams extending from a second side of the flex plate, the second side of the flex plate different from the first side of the flex plate.

24. The system of claim 23, wherein: the beams in the first pair of bending beams are parallel to one another.

25. The system of claim 24, wherein: the first and second sides of the flex plate are opposite one another.

26. The system of claim 25, wherein: at least one beam in the first pair of beams is co-linear with a beam in the second pair of beams.

27. The system of claim 22, wherein each at least one displacement sensor comprises an Eddy current sensor.

28. The system of claim 22, wherein the at least one displacement sensor comprises a plurality of displacement sensors.

29. The system of claim 22, wherein each bending beam of the plurality of bending beams is mechanically coupled to the trailer plate first surface.

30. The system of claim 29, further comprising: a shim inserted between each bending beam of the plurality of bending beams and the trailer plate first surface.

31. A system for measuring a load force in a fifth-wheel coupling system having a fifth-wheel mounted on a vehicle and a kingpin provided on, and extending from, a first surface of a trailer plate on a trailer, the system comprising: a flex plate, having an opening defined therein to accommodate and at least partially surround the kingpin without contacting the kingpin, configured to couple to the trailer plate first surface with a flex gap defined between the flex plate and the trailer plate first surface; a plurality of bending beams, extending from the flex plate, configured to couple to the trailer plate first surface with a beam gap defined between each bending beam of the plurality of bending beams and the trailer plate first surface; and at least one displacement sensor provided in each bending beam of the plurality of bending beams, wherein each displacement sensor is configured to detect a force in a direction parallel to a longitudinal axis of the kingpin.

32. The system of claim 31 , wherein the plurality of bending beams comprises: a first pair of bending beams extending from a first side of the flex plate; and a second pair of bending beams extending from a second side of the flex plate, the second side of the flex plate different from the first side of the flex plate.

33. The system of claim 32, wherein: the beams in the first pair of bending beams are parallel to one another.

34. The system of claim 33, wherein: the first and second sides of the flex plate are opposite one another.

35. The system of claim 34, wherein: at least one beam in the first pair of beams is co-linear with a beam in the second pair of beams.

36. The system of claim 31 , wherein each at least one displacement sensor comprises an Eddy current sensor.

37. The system of claim 31 , wherein the at least one displacement sensor comprises a plurality of displacement sensors.

38. The system of claim 31 , wherein each bending beam of the plurality of bending beams is configured to be mechanically coupled to the trailer plate first surface.

39. The system of claim 38, further comprising: a shim configured to be inserted between each bending beam of the plurality of bending beams and the trailer plate first surface.