Description:TECHNICAL FIELD
[0001] The present disclosure relates to the field of wagon coupling. In particular, the present disclosure provides a coupling assembly to efficiently transfer draw loads or buff loads while providing a safety feature to prevent damage under excessive loads.

BACKGROUND
[0002] Vehicles, including rail vehicles like locomotives, freight cars, passenger coaches, boxcars, and others, are equipped with couplings positioned at both ends. Couplings play a critical role in connecting railway wagons, facilitating efficient transportation of goods and materials. Traditionally, couplings have relied on mechanical linkages to securely join wagons together, ensuring stability and safety during transit. However, conventional designs often suffer from limitations related to load absorption, user control over engagement thresholds, and post-impact maintenance.
[0003] Exisitng couplings primarily focused on mechanical designs that lack the flexibility to selectively engage load absorption and dissipation mechanisms based on varying loads. Additionally, existing solutions offer limited thresholds at which impact absorption devices are activated, resulting in suboptimal performance in different operating conditions. Moreover, the inability to adjust load thresholds after deployment presents a significant drawback in terms of adaptability and maintenance.
[0004] There is, therefore, a need for a draft gear with shear-off functionality. Particularly, there is a need for a draft gear having an adjustable load threshold, that is easier to maintain and replace, and allows for engagement of appropriate systems for absorption and dissipation of loads at a wide range of loads.

OBJECTS OF THE PRESENT DISCLOSURE
[0005] A general object of the present disclosure is to provide a coupling assembly to efficiently absorb and transfer draw loads and buff loads.
[0006] A general object of the present disclosure is to provide a coupling assembly to reduce the risk of accidents or injuries associated with coupling failure
[0007] An object of the present disclosure is to provide a coupling assembly that disengages from a load to allow a deformation tube to absorb impact load when it exceeds a predefined load.
[0008] Yet another object of the present disclosure is to provide a coupling assembly where the predefined load threshold is adjustable based on requirements.

SUMMARY
[0009] Aspects of the present disclosure relate to a coupling assembly to efficiently transfer draw loads or buff loads while providing a safety feature to prevent damage under excessive loads.
[0010] An aspect of the present disclosure elaborates upon a coupling assembly for coupling linkage that includes a housing having an inner cavity defining a longitudinal axis and a drawbar positioned within the inner cavity of the housing for translation motion during draw loads or buff loads along the longitudinal axis of the housing, the drawbar having a coupling end projecting out of the housing and configured to be coupled to a load. Additionally, the coupling assembly includes a center plate located within the inner cavity of the housing and coupled to the drawbar through a plurality of cushioning means for the transfer of load from the drawbar to the center plate. The center plate is coupled to the housing through one or more shear pins. The one or more shear pins are configured to shear off when the draw loads or the buff loads applied to the drawbar are greater than a predefined load, thereby allowing the drawbar to move along the horizontal axis of the housing.
[0011] In an aspect, the drawbar may be configured through a hole of the center plate. The hole of the center plate having a first set of wear bushes that may be configured to provide a guiding surface to move the drawbar along the longitudinal axis of the housing.
[0012] In an aspect, at least some of the cushioning means are configured between the center plate and the coupling end of the drawbar. The remaining cushioning means are configured between the other side of the center plate and fixed by means of a castle nut and an end disc fixed at an inner end of the drawbar. The castle nut and the end disc are configured to compress the cushioning means to preload the cushioning means. The plurality of cushioning means may be a set of elastic elements having elastic resilience to absorb the draw loads and the buff loads transmitted thereto through the drawbar.
[0013] In an aspect, the coupling assembly includes a torsion plate mounted between the coupling end of the drawbar and the housing. The torsion plate may be configured to resist the torsional movement of the drawbar about the longitudinal axis during draw loads or buff loads on the drawbar.
[0014] In an aspect, the coupling assembly includes a second set of wear bushes provided between the coupling end of the drawbar and the housing. The second set of wear bushes may be configured to provide a guiding surface to move the drawbar along the longitudinal axis of the housing.
[0015] In an aspect, the one or more shear pins include a circumferential groove dividing the corresponding shear pin between two portions. The circumferential groove may enable shearing off of the shear pins at the circumferential groove when the draw loads or the buff loads applied to the drawbar are greater than the predefined load threshold. The one or more shear pins may be configured such that, when assembled between the center plate and the housing, the circumferential groove may be located at an interface between the the center plate and the housing.
[0016] In an aspect, the coupling assembly includes a deformation tube located coaxially and coupled to an inner end of the housing by thread fitting. The deformation tube may be configured to accommodate the center plate and the drawbar in an event of shearing off the shear pin and the center plate and the drawbar moving inwards in the longitudinal direction under the buff load.
[0017] In an aspect, the deformation tube and the center plate may be profiled such that in the event of the center plate moving inward in the longitudinal direction under the buff load leads to the deformation of the deformation tube to absorb the buff load.
[0018] In an aspect, the coupling assembly includes a shear-off indication bolt positioned between the housing and center plate, the shear-off indication bolt configured to provide an indication of shearing of the one or more shear pins.
[0019] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0021] FIG. 1A illustrates an exemplary perspective view of a coupling assembly, according to embodiments of the present disclosure.
[0022] FIG. 1B illustrates an exemplary perspective cross-section view of a coupling assembly, according to embodiments of the present disclosure.
[0023] FIG. 2A illustrates an exemplary cross-section representation of reversible energy operations of the coupling assembly, according to embodiments of the present disclosure.
[0024] FIG. 2B illustrates an exemplary cross-section representation of buff load on the coupling assembly, according to embodiments of the present disclosure.
[0025] FIG. 2C illustrates an exemplary cross-section representation of the draw load on the coupling assembly, according to embodiments of the present disclosure.
[0026] FIGs. 3 illustrate example orthogonal and isometric views of the shear pins respectively, according to embodiments of the present disclosure.
[0027] FIGs. 4A-4G illustrates an exemplary cross-section view representing the multiple positions of the drawbar and a center plate of the coupling assembly during buff load, according to embodiments of the present disclosure.
DETAILED DESCRIPTION
[0028] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such details as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosures as defined by the appended claims.
[0029] As used herein, “substantially” means largely or considerably, but not necessarily wholly, or sufficiently to work for the intended purpose. The term “substantially” thus allows for minor, insignificant variations from an absolute or perfect state, dimension, measurement, result, or the like as would be expected by a person of ordinary skill in the art, but that does not appreciably affect overall performance.
[0030] Throughout the present disclosure, “attachment means” includes, but is not limited to, screws, nails, rivets, adhesives, magnets, hook and loop fasteners, hook and slot fasteners, interlocking elements, friction-grip releasable fasteners, fastening straps, and the like.
[0031] Embodiments explained herein relate to the field of wagon coupling. In particular, the present disclosure provides a coupling assembly to efficiently transfer draw loads or buff loads while providing a safety feature to prevent damage under excessive loads
[0032] An aspect of the present disclosure elaborates upon a coupling assembly for coupling linkage that includes a housing, drawbar, and a center plate. The housing having an inner cavity defining a longitudinal axis. The drawbar may be positioned within the inner cavity of the housing for translation motion during draw loads or buff loads along the longitudinal axis of the housing. The drawbar having a coupling end projecting out of the housing. The drawbar may be configured to be coupled to a load. The center plate may be located within the inner cavity of the housing and coupled to the drawbar through a plurality of cushioning means for the transfer of load from the drawbar to the center plate. The center plate may be coupled to the housing through one or more shear pins. The one or more shear pins may be configured to shear off when the draw loads or the buff loads applied to the drawbar are greater than a predefined load, thereby allowing the drawbar to move along the horizontal axis of the housing.
[0033] Referring to FIGs. 1A and 1B, the proposed coupling assembly 100 (interchangeably referred to as assembly 100 hereafter) for coupling linkage is disclosed. The assembly 100 includes a housing 102 having an inner cavity defining a longitudinal axis and a drawbar 104 positioned within the inner cavity of the housing 102 for translation motion during draw loads or buff loads along the longitudinal axis of the housing 102. The drawbar 104 having a coupling end 106 projecting out of the housing 102 and configured to be coupled to a load. Additionally, the coupling assembly 100 includes a center plate 108 located within the inner cavity of the housing 102 and coupled to the drawbar 104 through a plurality of cushioning means 110 for transfer of load from the drawbar 104 to the center plate 108. The center plate 108 can be coupled to the housing 102 through one or more shear pins 112. The one or more shear pins 112, such as shear pins 112-1, 112-2 (collectively referred to as shear pins 112). The shear pin 112 can be configured to shear off when the draw loads or the buff loads applied to the drawbar 104 are greater than a predefined load, thereby allowing the drawbar 104 to move along the horizontal axis of the housing 102.
[0034] In some embodiment, the housing 102 can be configured with a mounting flange 130 to coupled with a support structure. In some embodiments, the support structure may be any one of locomotives, rail cars, carriages or coaches, bumpers, buffer stops, and the like. The assembly 100 may be installed may be installed on the support structures through the mounting flange 130. In some embodiment, the coupling end 106 defines a yoke-type structure that can be configured to accommodate the load. The coupling end 106 coupling with the load can be flexible to absorb the impact of the load.
[0035] In some embodiments, the draw loads and the buff loads may be indicative of loads applied in a substantially horizontal direction with respect to a ground surface. The draw loads may be indicative of forces that cause structures to stretch or expand, and the buff loads may be indicative of forces that cause structures to compress or contract. The assembly 100 may be configured to protect the support structure from the draw loads or buff loads applied thereto during acceleration or deceleration of the support structure, such as locomotives.
[0036] In some embodiment, the center plate 108 having a cylindrical member 108-1 and a disc 108-2 configured within the center plate 108. The disc 108-2 having a hole configured to accommodate the drawbar 104 to pass through the hole of the disc 108-2. The hole of the disc 108-2 having a first set of wear bushes 114 configured to provide a guiding surface to move the drawbar 104 along the longitudinal axis of the housing 102. The cylindrical member 108-1 includes one or more cavities to accommodate corresponding the one or more shear pins 112. The cylindrical member 108-1 and the housing 102 coupled through the one or more shear pins 112. For example, the disc 108-2 can be used as a hub for the drawbar 104 to provide support and guide the movement of the drawbar. The disc 108-2 can be positioned center of the center plate 108.
[0037] In some embodiment, at least some of the cushioning means 110-1 can be configured between the center plate 108 and the coupling end 106 of the drawbar 104 and the remaining cushioning means 110-2 (collectively referred to as cushioning pin 110) can be configured between the other side of the center plate 108 and fixed by means of a castle nut 116 and an end disc 118 fixed at an inner end of the drawbar 104. The castle nut 116 and the end disc 118 are configured to compress the cushioning means 110 to preload the cushioning means 110. In such examples, the locomotive may apply draw loads to the drawbar 104 when the locomotive accelerates, and the locomotive may apply buff loads to the drawbar 104 when it decelerates or brakes. Further, locomotives may apply both draw and buff loads during collisions. The cushioning means 110 can be a set of elastic elements having elastic resilience to absorb the draw loads and the buff loads transmitted thereto through the drawbar 104.
[0038] In some embodiment, the assembly 100 includes a torsion plate 120 mounted between the coupling end 106 of the drawbar 104 and the housing 102. The torsion plate 120 can be configured to resist the torsional movement of the drawbar 104 about the longitudinal axis during draw loads or buff loads on the drawbar 104. In such an example, the draw load and the buff load can be applied in any direction (such as an acute angle) which can push the drawbar 104 to rotate in any direction either clockwise or anti-clockwise, in such event the torsion plate 120 resist torsional movement of the drawbar 104.
[0039] In some embodiment, the assembly 100 includes a second set of wear bushes 122 provided between the coupling end 106 of the drawbar 104 and the inner cavity of the housing 102. The second set of wear bushes 122 can be configured to provide a guiding surface to move the drawbar 104 along the longitudinal axis of the housing 102. In some embodiment, the first 114 and the second 122 set of wear bush can be configured to ensuring that the drawbar 104 moves smoothly and accurately along its intended path (the lengthwise direction) within the housing 102.
[0040] In some embodiment, the assembly 100 includes a deformation tube 124 located coaxially and coupled to an inner end of the housing 102 by thread fitting. The deformation tube 124 having a greater diameter corresponding to the cylindrical member 108-1 of the center plate 108 to accommodate the center plate 108 within. The deformation tube 124 and the cylindrical profile 108-1 of the center plate 108 may be profiled such that in the event of the center plate 108 along with the drawbar 104 moving inward in the longitudinal direction under the buff load leads to the deformation of the deformation tube to absorb the buff load.
[0041] In some embodiment, the assembly 100 includes a shear-off indication bolt 126 positioned between the housing 102 and the cylindrical member 108-1 of the center plate 108. The shear-off indication bolt 126 can be configured to provide an indication of shearing of the one or more shear pins 112.
[0042] Referring to FIGs. 2A to 2C illustrate a cross-section representation of the reversible energy operation of the coupling assembly 100 is disclosed. The reversible energy operations include the draw load and the buff load applied on the assembly at the same time compressing and expanding the corresponding cushioning means 110 positioned over the drawbar 104. The cushioning means 110 can be configured to absorb the draw load and the buff load during impact, which leads to reducing the impact of the wagon of the locomotive. The cushioning means 110 can be configured to dissipate the absorbed impact energy through the center plate 108 that transfers to the housing 102.
[0043] When the draw loads or the buff loads are less than the predefined load, the drawbar 104 may communicate the force to the cushioning means 110, and the cushioning means 110 may absorb the impact loads. However, when the impact load is greater than the predefined load. The impact load may also be greater than the elastic resilience of the cushioning elements. In some embodiments, the draw/buff loads may exceed the predefined load during collisions or accidents. In such embodiments, the impact load may be communicated to the housing 102 from the drawbar 104 through the cushioning means 110. In some embodiments, the housing 102 may transmit the impact load therefrom to the shear pins 112. When the impact load is greater than the predefined load, the impact load may be sufficient to shear off the shear pins 112 as shown in FIGs. 4A to 4G. In such embodiments, shearing of the shear pins 112 may allow the drawbar 104 and the components associated therewith, to move inward along the longitudinal axis of the housing 102 during buff load.
[0044] When the draw load is greater than the predefined load during impact or accident, the shear pins 112 allow the drawbar 104 and associated components therewith, to move outward along the longitudinal axis of the housing 102, as result the coupling end 106 disengage with load to reduce the impact on the wagon or compartments of the locomotive. In such an example, the disengagement helps to minimize damage to the locomotive and passengers onboard the locomotive.
[0045] Referring to FIG. 3, the one or more shear pins 112 include a circumferential groove 302 dividing the corresponding shear pin 112 between two portions, the circumferential groove 302 enabling shearing off of the shear pins 112 at the circumferential groove 302 when the draw loads or the buff loads applied to the drawbar 104 is greater than the predefined load threshold. The one or more shear pins 112 are configured such that, when assembled between the center plate 108 and the housing 102, the circumferential groove 302 is located at an interface between the center plate 108 and the housing 102. The circumferential groove 302 of the shear pin 112 allows the shear pin 112 to shear off during impact or accident of the locomotive. In the event of shearing off of the shear pins 112 allow the assembly 100 to absorb and transfer impact load in an incident of accident or impact.
[0046] In some embodiment, the shear pins 112 may be configured between the housing 102 and the cylindrical member 108-1 of the center plate 108 to absorb the predefined load in the event of an accident or impact of the locomotive. In such an example, when the impact load exceeds the predefined load, the shear pin 112 breaks into two parts, a first part of the shear pin 112 moves with the center plate 108 and second part of the shear pin stuck in the housing 102.
[0047] Referring to FIGs. 4A to 4G, illustrates a cross-section view representing the multiple positions of the drawbar and associated components therewith during buff load. When the buff load is greater than the predefined load the drawbar 104 moves inward along the longitudinal axis of the housing 102, shearing off the shear pin 112 and deforming the deformarion tube 124. The deformation tube 124 can be accommodated the drawbar 104 and associated components therewith, and also a large portion of the deformation tube 124 inner profile is less than the outer profile of the cylindrical member 108-1 of the center plate 108 that facilitates the absorption of the impact load. The deformation tube 124 can be configured to absorb load when the shear pins 112 and cushioning means 110 fail during buff load.
[0048] In some example embodiment, the assembly 100 can be suitable for use in vehicles, especially in rail applications, where the loads and stresses remain within a predefined limit during typical operation. During the acceleration and deceleration of vehicles, forces may act on the drawbar 104, and these forces can be absorbed and dispersed by the cushioning means 110. Moreover, the assembly 100 can be modified to improve vehicle safety in the event of accidents or collisions by incorporating additional, stronger shock-absorbing components. These added elements are designed to withstand forces exceeding a predefined threshold, such as those encountered during accidents or collisions, thereby enhancing passenger safety and preventing vehicle derailment. If the forces surpass the predefined threshold, the assembly 100 will break the shear pins 112, allowing the drawbar 104 to engage the shock-absorbing components like the deformation tube 124. Consequently, the assembly described herein offers both load absorption and dissipation capabilities during normal operation and collision scenarios.
[0049] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the disclosure is determined by the claims that follow. The disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0050] The present disclosure provides a coupling assembly with shear-off pins.
[0051] The present disclosure provides a coupling assembly to efficiently absorb and transfer draw loads and buff loads.
[0052] The present disclosure provides a coupling assembly to reduce the risk of accidents or injuries associated with coupling failure.
[0053] The present disclosure provides a coupling assembly that disengages from a load to allow a deformation tube to absorb impact load when it exceeds a predefined load.
[0054] The present disclosure provides a coupling assembly where the predefined load is adjustable based on requirements.
, Claims:1. A coupling assembly (100) for coupling linkage, the coupling assembly (100) comprising:
a housing (102) having an inner cavity defining a longitudinal axis;
a drawbar (104) positioned within the inner cavity of the housing (102) for translation motion during draw loads or buff loads along the longitudinal axis of the housing (102), the drawbar (104) having a coupling end (106) projecting out of the housing (102) and configured to be coupled to a load; and,
a center plate (108) located within the inner cavity of the housing (102) and coupled to the drawbar (104) through a plurality of cushioning means (110) for transfer of load from the drawbar (104) to the center plate (108);
wherein the center plate (108) is coupled to the housing (102) through one or more shear pins (112), and wherein the one or more shear pins (112) are configured to shear off when the draw loads or the buff loads are applied to the drawbar (104) are greater than a predefined load, thereby allowing the drawbar (104) to move along the horizontal axis of the housing (102).
2. The coupling assembly (100) as claimed in claim 1, wherein the drawbar (104) is configured through a hole of the center plate (108), the hole of the center plate (108) having a first set of wear bushes (114), wherein the first set of wear bushes (114) is configured to provide a guiding surface to move the drawbar (104) along the longitudinal axis of the housing (102).
3. The coupling assembly (100) as claimed in claim 1, wherein at least some of the cushioning means (110-1) are configured between the center plate (108) and the coupling end (106) of the drawbar (104), the remaining cushioning means (110-2) are configured between the other side of the center plate (108) and fixed by means of a castle nut (116) and an end disc (118) fixed at an inner end of the drawbar (104) and wherein the castle nut (116) and the end disc (118) are configured to compress the cushioning means (110) to preload the cushioning means (110).
4. The coupling assembly (100) as claimed in claim 1, wherein the plurality of cushioning (110) means is a set of elastic elements having elastic resilience to absorb the draw loads and the buff loads transmitted thereto through the drawbar (104).
5. The coupling assembly (100) as claimed in claim 1, wherein the coupling assembly (100) comprises a torsion plate (120) mounted between the coupling end (106) of the drawbar (104) and the housing (102), the torsion plate (120) configured to resist torsional movement of the drawbar (104) about the longitudinal axis during draw loads or buff loads on the drawbar (104).
6. The coupling assembly (100) as claimed in claim 1, wherein the coupling assembly (100) comprises a second set of wear bushes (122) provided between the coupling end (106) of the drawbar (104) and the housing (102), the second set of wear bushes (122) configured to provide a guiding surface to move the drawbar (104) along the longitudinal axis of the housing (102).
7. The coupling assembly (100) as claimed in claim 1, wherein the one or more shear pins (112) comprise a circumferential groove (302) dividing the corresponding shear pin (112) between two portions, the circumferential groove (302) enabling shearing off of the shear pins (112) at the circumferential groove (302) when the draw loads or the buff loads applied to the drawbar (104) is greater than the predefined load.
8. The coupling assembly (100) as claimed in claim 7, wherein the one or more shear pins (112) are configured such that, when assembled between the center plate (108) and the housing (102), the circumferential groove (302) is located at an interface between the center plate (108) and the housing (102).
9. The coupling assembly (100) as claimed in claim 1, wherein the coupling assembly (100) comprises a deformation tube (124) located coaxially and coupled to an inner end of the housing (102) by thread fitting, the deformation tube (124) configured to accommodate the center plate (108) and the drawbar (104) in an event of shearing of the shear pin (112) and the center plate (108) and the drawbar (104) moving inwards in the longitudinal direction under the buff load.
10. The coupling assembly (100) as claimed in claim 9, wherein the deformation tube (124) and the center plate (108) are profiled such that in the event of the center plate (108) along with the drawbar (104) moving inward in the longitudinal direction under the buff load leads to deformation of the deformation tube to absorb the buff load.
11. The coupling assembly (100) as claimed in claim 1, wherein the coupling assembly (100) comprises a shear-off indication bolt (126) positioned between the housing (102) and center plate (108), the shear-off indication bolt (126) configured to provide an indication of shearing of the one or more shear pins (112).