Double friction traction device assembly

Abstract

A dual friction hitch assembly for a car coupling system of a rail car includes a housing having an interior chamber. One or more friction shoes are disposed within the interior chamber. A first load block has, defines, or otherwise provides a first angled interface surface that interfaces with the one or more friction shoes. A second load block has, defines, or otherwise provides a second angled interface surface that interfaces with the one or more friction shoes.

Description

[0001] Related Applications

[0002] This application is related to and claims priority to U.S. Patent Application No. 17 / 007,317 filed on August 31, 2020, which in turn is related to and claims priority to U.S. Provisional Patent Application No. 62 / 988,435 filed on March 12, 2020, the entire contents of each of which are incorporated herein by reference. Technical Field

[0003] Embodiments of the present disclosure generally relate to traction devices for rail vehicles (eg, rail cars). Background Art

[0004] A rail vehicle travels along a railway having a track including rails. A rail vehicle includes one or more truck assemblies supporting one or more vehicle bodies.

[0005] U.S. Patent No. 761,795 discloses a double spring friction traction sling. U.S. Patent Application Publication No. 2016 / 0362121 discloses a railway carriage traction device. U.S. Patent No. 6,478,173 discloses a railway carriage traction device with a long stroke. U.S. Patent Application Publication No. 2008 / 0290058 discloses a railway carriage traction device. U.S. Patent No. 5,351,844 discloses an elastomeric spring unit.

[0006] Traction devices using Coulomb damping are susceptible to a sliding phenomenon known as "stick-slip" which is believed to be caused primarily by an inconsistent load path into the friction element of such a traction device. When the traction device is engaged, forces react against the load plate which creates a moment about the friction element because it is perpendicular to the sliding wall. When the traction device is relaxed, forces react against the top angled load block which transfers the offset load directly through the friction element into the sliding wall. This difference between the moment reaction force and the offset force creates stick-slip which results in an inconsistent load-displacement curve. This inconsistency is undesirable for optimal traction device operation.

[0007] Test data obtained from known Coulomb damped traction devices show that the load / unload curve is not smooth. This is due to stick-slip of the friction components, which impedes the performance of the traction device. Summary of the invention

[0008] There is a need for a traction device that eliminates, minimizes, or otherwise reduces the potential for stick-slip.

[0009] With these needs in mind, certain embodiments of the present disclosure provide a dual friction hitch assembly for a car coupling system of a rail car. The dual friction hitch assembly includes a housing having an interior chamber. One or more friction shoes are disposed within the interior chamber. A first load block provides a first angled interface that interfaces with the one or more friction shoes. A second load block provides a second angled interface that interfaces with the one or more friction shoes. In at least one embodiment, the first angled interface is substantially a mirror image of the second angled interface.

[0010] The one or more friction shoes may be disposed between the first load block and the second load block.At least a portion of the first load block and at least a portion of the second load block may be located within the interior chamber of the housing.

[0011] As an example, the one or more friction shoes may include three friction shoes.

[0012] A spring pack may be disposed within the interior chamber between the base of the housing and the second load block.

[0013] As an example, the first angled interface includes a first angled surface of the one or more friction shoes, the first angled surface abutting against a second angled surface of the first load block. In addition, the second angled interface includes a third angled surface of the one or more friction shoes, the third angled surface abutting against a fourth angled surface of the second load block.

[0014] The first load block and the second load block may be coaxial with the housing.The one or more friction shoes may be spaced apart from a central longitudinal axis of the housing.

[0015] Certain embodiments of the present disclosure provide a method of forming a dual friction hitch assembly for a car coupling system of a rail car. The method includes: disposing one or more friction shoes in an interior chamber of a housing; providing a first angled interface between a first load block and the one or more friction shoes; and providing a second angled interface between a second load block and the one or more friction shoes. In at least one embodiment, the method also includes making the first angled interface and the second angled interface substantially mirror images. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Shown is a top view of a first rail car coupled to a second rail car.

[0017] Figure 2 A perspective top view of a car coupling system is shown.

[0018] Figure 3 A front view of a dual friction traction device assembly is shown according to one embodiment of the present disclosure.

[0019] Figure 4 Shows Figure 3 A top view of the dual friction traction device assembly.

[0020] Figure 5 Shows Figure 3 A perspective top view of the housing of a dual friction traction device assembly.

[0021] Figure 6 Shows Figure 3 A top view of the sliding component of the dual friction traction device assembly.

[0022] Figure 7 Shown through Figure 4 A cross-sectional view of the dual friction traction device assembly taken along line 7-7.

[0023] Figure 8 A similar diagram according to an embodiment of the present disclosure is shown. Figure 7 An axial cross-sectional view of a dual friction traction device assembly.

[0024] Fig. 9 A perspective top view of a vehicle cabin coupling system including a hitch assembly is shown according to one embodiment of the present disclosure.

[0025] Fig.10 A flow chart is shown of a method of forming a dual friction hitch assembly for a car coupling system of a rail car according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0026] When read in conjunction with the accompanying drawings, the foregoing summary of the invention and the following detailed description of certain embodiments will be better understood. When used herein, the elements or steps listed in the singular and beginning with the word "a" or "an" should be understood as not necessarily excluding the plural form of the elements or steps. In addition, reference to "an embodiment" is not intended to be interpreted as excluding the existence of additional embodiments that also include the listed features. In addition, unless explicitly stated to the contrary, the embodiments of "including" or "having" one or more elements with a specific condition may include additional elements without the condition.

[0027] Figure 1 A top view of a first rail car 10 coupled to a second rail car 12 is shown. The first rail car 10 and the second rail car 12 are configured to travel along a railroad 14 having rails 16 and 18. A coupler 20 of the first rail car 10 is connected to a coupler 22 of the second rail car 12.

[0028] Figure 2A perspective top view of a car coupling system 30 is shown. The first rail car 10 and the second rail car 12 include a car coupling system 30. The car coupling system 30 includes a coupler 32 (e.g., Figure 1 3 and 4. The coupling 20 or coupling 22 is shown), a traction beam 34, and a traction device 36 with a yoke 38. The coupling 32 is supported at a first end 40 by the traction beam 34 and at an opposite second end 42 by the traction device 36 or a buffer unit with the yoke 38. The traction device 36 or the buffer unit is restrained within the traction beam 34 by a pair of front stops 44 and a pair of rear stops 46.

[0029] According to an embodiment of the present disclosure, the traction device 36 may be replaced by a dual friction traction device assembly 100, such as Figure 3 -10 and as described herein.

[0030] Figure 3 A front view of a dual friction hitch assembly 100 is shown according to one embodiment of the present disclosure. Dual friction hitch assembly 100 includes a housing 102 and a first or top load block, such as a friction block 104 (eg, a wedge) extending from housing 102 .

[0031] The housing 102 includes a base 106, which may include an extended platform 108. Inwardly angled support walls 110 may angle upward and inward toward each other from the platform 108. The support walls 110 may be connected to linear beams 112, which are connected to cross beams 114.

[0032] Wall 116 extends from platform 108. Wall 116 may be located within support wall 110, linear beam 112, and cross beam 114. Wall 116 is generally orthogonal to platform 108. An interior chamber 118 is defined between wall 116 and base 107. Figure 3 In the orientation shown, the platform 108 is horizontal and the inner wall 116 is vertical. It should be understood that the orientation can be changed so that the platform 108 is vertical and the inner wall 116 is horizontal. That is, Figure 3 The orientation shown is only an example.

[0033] The support wall 110, the linear beams 112, and the cross beams 114 may provide a sturdy support for the housing 102. Alternatively, the housing 102 may not include the support wall 110, the linear beams 112, and the cross beams 114. Alternatively, the wall 116 may extend upward from the base 106 without a support structure surrounding a portion of the wall 116.

[0034] The friction block 104 extends outwardly from the open end 119 of the inner chamber 118. The friction block 104 may be wedge-shaped. The friction block 104 includes a distal end 120 connected to a head 121, which may expand outwardly from the distal end 120 toward the housing 102.

[0035] Figure 4 Shows Figure 3 FIG. 1 is a top view of a dual friction traction device assembly 100. As shown, the friction block 104 extends upwardly out of the interior chamber 118. One or more friction shoes 122 (e.g., sliding members having non-traction outer sliding walls) are retained within the interior chamber 118 below the friction block 104. As shown, three friction shoes 122 can be regularly spaced within the interior chamber 118 below the friction block 104. Optionally, more or fewer friction shoes 122 can be used. For example, a single continuous friction shoe 122, such as a friction ring, can be disposed within the interior chamber 118 below the friction block 104.

[0036] Figure 5 Shows Figure 3 1 is a perspective top view of the housing 102 of the dual friction traction device assembly 100. The size and shape of the inner surface 124 of the wall 116 can be designed to slidably retain the friction shoe 122. For example, the inner surface 124 can be shaped to conform to the outer surface of the friction shoe 122.

[0037] Figure 6 Shows Figure 3 1. A top view of a friction shoe 122 of a dual friction traction device assembly 100. The friction shoe 122 includes an inner side wall 130 that may include a notch 132. A side wall 134 is angled outwardly from the inner side wall 130. The side wall 134 is connected to an outer side wall 136 opposite the inner side wall 130. The outer side wall 136 includes a side wing 138 that is recessed relative to a central vertex 139. For example, the side wing 138 extends upward and arcuately from the side wall 136 toward the central vertex 139. The outer side wall 136 is configured to abut against an interacting portion of the inner surface 124 of the wall 116 (e.g., Figure 5 shown).

[0038] Figure 7 Shown through Figure 4 A cross-sectional view of the dual friction traction device assembly 100 taken along line 7-7. Figure 3 -7, an elastomeric spring assembly 140 is retained within the interior chamber 118 between the base 106 and a second or bottom load block, such as an angled follower 142 (e.g., a wedge or block). In at least one embodiment, the spring assembly 140 includes a series of elastomeric pads 141 and a metal (e.g., steel) plate 143. The follower 142 and the friction shoe 122 are retained within the interior chamber of the housing 102. The elastomeric pads 141 can be formed of a certain material and design so that they provide sufficient stiffness and load-bearing capacity and sufficient hysteresis to contribute to the overall damping capacity of the dual friction traction device assembly 100.

[0039] The load block or follower 142 includes an expanded end 144 that abuts an end 146 of the spring pack 140. The angled interface having an angled wall or surface 148 converges toward a reduced end 150 (opposite the expanded end 144) having a smaller diameter or width than the expanded end 144.

[0040] The angled wall 148 abuts against an angled lower surface 152 of the friction shoe 122. The reduced end 150 may be disposed within a space 154 between the friction shoes 122. For example, the reduced end 150 may be centered about a central longitudinal axis 156 of the housing 102 directly below the friction block 104.

[0041] The friction shoe 122 also includes an angled upper surface 160 that abuts against an angled lower surface 162 of the load or friction block 104. The angled lower surface 162 of the friction block 104 is angled inwardly and downwardly from the head 121 of the friction block 104. The friction block 104 is above the follower 142, wherein the friction shoe 122 is disposed within the interior chamber 118 between the friction block 104 and the follower 142. The friction shoe 122 abuts against the angled surfaces of the friction block 104 and the follower 142. The friction block 104 and the follower 142 can be centered about the central longitudinal axis 156. For example, the friction block 104 and the follower 142 can be coaxial with the housing 102. The friction shoe 122 can be spaced apart from the central longitudinal axis 156 and radially surround the central longitudinal axis 156.

[0042] Thus, a first angled interface 190 is disposed (eg, exists) between the friction block 104 and the one or more friction shoes 122. Additionally, a second angled interface 192 is disposed between the one or more friction shoes 122 and the follower 142.

[0043] The dual friction traction device assembly 100 can have the same fit, form and function as a standard traction device. For example, the dual friction traction device assembly 100 can replace Figure 2 The traction device 36 shown in FIG. The dual friction traction device assembly 100 can provide a direct replacement for existing traction devices. The dual friction traction device assembly 100 can be used for new car construction as well as repair and maintenance.

[0044] Due to the design of the current yoke in production, the dual friction draft gear assembly 100, along with the draft gear in production, compresses in the same direction regardless of whether a buffer load or a traction load is applied. When a buffer or traction load is applied through the follower 142, the friction block 104 pushes toward the base 106 of the housing 102 in the direction of arrow A. As the friction block 104 moves toward and / or into the interior chamber 118 in the direction of arrow A, the angled lower surface 162 of the friction block applies a force into the angled upper surface 160 of the friction shoe 122. In this way, the friction shoe 122 applies the angled load into the friction block 104, and vice versa. The angled load is then transferred into the inner surface 124 of the wall 116 of the housing 102.

[0045] When the friction block 104 (which is at the top, such as Figure 7 106 of the housing 102, the friction block 104 also applies an angled load into the angled wall 148 of the follower 142. The sum of the angled loads applied to the follower 142 produces a pure compressive load that pushes the follower 142 uniformly toward the base 106 of the housing 102 in the direction of arrow A. As the follower 142 moves toward the base 106 in the direction of arrow A, the follower 142 applies a compressive force into the spring pack 140.

[0046] The first angled interface 190 is a mirror image (or at least substantially mirror image within + / - 5 degrees, for example) of the second angled interface 192. The angles of the first angled interface 190 and the second angled interface 192 may be, for example, between 20 and 75 degrees.

[0047] As described herein, the dual friction hitch assembly 100 includes a first or top load block (e.g., friction block 104) having a first angled interface surface 190 that interfaces with one or more friction shoes 122, and a second or bottom load block (e.g., follower 142) having a second angled interface surface 192 that interfaces with the one or more friction shoes 122. The first angled interface surface 190 is substantially a mirror image of the second angled interface surface 192 (e.g., within + / - 5 degrees).

[0048] The friction shoe 122 (e.g., the outer sidewall 136) and the inner surface 124 of the wall 116 of the housing 102 may be machined to remove any traction. Any traction on these surfaces may create an uneven load that is transmitted into the housing 102 through the friction shoe 122. Due to the geometry of the mirrored angled interfaces 190 and 192, the offset load does not create a moment about the outer sidewall 136 of the friction shoe 122 that may otherwise induce tilting. By eliminating or reducing this moment, the risk of the friction shoe 122 sticking in the housing 102 is eliminated or reduced. The mirroring of the angled interfaces 190 and 192 may be within a predetermined tolerance, such as within + / - 5 degrees.

[0049] The elastomeric spring group 140 provides additional damping capacity over conventional steel coil springs. The combination of the hysteresis of the nonlinear elastomeric spring group 140, the friction damping created as the sliding outer sidewall 136 of the friction shoe 104 travels along the inner surface 124 of the wall 116, and the elimination or otherwise reduction of stick-slip optimizes the load-displacement curve of the dual friction traction device assembly 100 and improves its performance.

[0050] When the cushioning or traction load is removed from the dual friction traction device assembly 100, the elastomeric spring pack 140 provides sufficient load to maintain an even distribution of contact between the follower 142 and the friction shoe 122. The reaction load supplied by the follower 142 through the friction block 104 applies equal and opposite forces to the friction shoe 122. These two equal and opposite forces allow the friction shoe 122 to apply an evenly distributed sliding friction load within the interior chamber 118 of the housing 102.

[0051] In at least one embodiment, a friction modifier or lubricant may be used with the inner chamber 118. Additionally, the dual friction traction device assembly 100 may also include one or more sliding friction plates.

[0052] The shape of the housing 102 can be different from the shape shown. For example, the cross-section of the housing 102 can be circular, rectangular, hexagonal, etc. At least a portion of the spring group 140 can be formed of a known spring material, such as Arnitel, and / or the like. In at least one other embodiment, the spring group 140 can be a coil spring.

[0053] One or more layers of friction shoes 122 may be used. For example, a single layer of three friction shoes 122 with 45 degree angled surfaces may be used, but additional layers with different angles may be used.

[0054] Figure 8 A similar diagram according to an embodiment of the present disclosure is shown. Figure 71 is an axial cross-sectional view of a dual friction traction device assembly 100. The friction block 104 may have a wedge-shaped portion. The friction block 104 provides a plunger configured to move toward the base 106 in the direction of arrow A, thereby applying force to the friction shoe 122, which in turn applies force to the follower 142, which in turn applies a compressive force to the spring group 140, as described herein. The spring group 140 may be a copolyester spring group.

[0055] As shown, a first angled interface 190 is disposed (eg, exists) between the friction block 104 and the one or more friction shoes 122. Additionally, a second angled interface 192 is disposed between the one or more friction shoes 122 and the follower 142.

[0056] Reference Figure 1 -8, in at least one embodiment, the dual friction traction device assembly 100 is used for a rail car (e.g. Figure 1 A car coupling system (e.g., Figure 2 The dual friction hitch assembly 100 includes a housing 102 having an interior chamber 118. One or more friction shoes 122 are disposed within the interior chamber 118. A first load block (e.g., friction block 104) has a first angled interface 190 that interfaces with the one or more friction shoes 122. A second load block (e.g., follower 142) has a second angled interface 192 that interfaces with the one or more friction shoes 122. In at least one embodiment, the first angled interface 190 is substantially a mirror image (e.g., within + / - 5 degrees) of the second angled interface 192. As shown, the one or more friction shoes 122 are disposed between the first load block and the second load block. At least a portion of the first load block and at least a portion of the second block are within the interior chamber 118 of the housing 102.

[0057] Fig. 9 A perspective top view of a car coupling system 200 including a dual friction hitch assembly 100 is shown according to one embodiment of the present disclosure. The car coupling system 200 can be manufactured with the dual friction hitch assembly 100. Optionally, the dual friction hitch assembly 100 can replace an existing hitch. For example, the car coupling system 200 can be retrofitted with the dual friction hitch assembly 100.

[0058] Fig.10A flow chart of a method of forming a dual friction hitch assembly for a car coupling system of a rail car according to one embodiment of the present disclosure is shown. The method includes disposing one or more friction shoes in an interior chamber of a housing at 300; providing a first angled interface between a first load block and the one or more friction shoes at 302; and providing a second angled interface between a second load block and the one or more friction shoes at 304. In at least one embodiment, the method further includes making the first angled interface and the second angled interface substantially mirror images.

[0059] The method may further include disposing the one or more friction shoes between the first load block and the second load block. The method may further include disposing at least a portion of the first load block and at least a portion of the second load block in an interior chamber of the housing. The method may further include disposing a spring assembly between a base of the housing and the second load block within the interior chamber.

[0060] In at least one embodiment, providing a first angled interface includes abutting a first angled surface of the one or more friction shoes against a second angled surface of the first load block. Providing a second angled surface includes abutting a third angled surface of the one or more friction shoes against a fourth angled surface of the second load block.

[0061] The method may further include aligning the first and second load blocks coaxially with the housing, and / or radially spacing the one or more friction shoes from a central longitudinal axis of the housing.

[0062] As described herein, instead of using a horizontal load plate to react to the torque from the friction shoe, the horizontal load plate is replaced with a friction block, friction shoe, and follower having angled interfaces therebetween. In at least one embodiment, because the angled interfaces can be mirror images of each other, the loading and unloading of load vectors through the dual friction traction device assembly 100 is symmetrical. The symmetrical loading and elimination of torque generated at the flat load plate both help eliminate, minimize, or otherwise reduce the ability of the friction elements to "stick and slip." Additionally, the dual angles (i.e., a first angled interface 190 between the friction block 104 and the one or more friction shoes 122, and a second angled interface 192 between the one or more friction shoes 122 and the follower 142, as shown in FIG. 1 ) provide a plurality of friction pads, each having a plurality of friction pads, and ... Figure 7 and 8 ) doubles the normal force of the friction element, allowing a softer spring to be used at the same impact load.

[0063] Thus, embodiments of the present disclosure provide a traction device that eliminates, minimizes, or otherwise reduces "stick-slip." As described above, "stick-slip" creates an undesirable load profile that reduces the effectiveness of the traction device in damping train loads and shock loads during humpbacks.

[0064] Embodiments of the present disclosure provide a traction device that provides symmetrical forces applied to the friction element for loading and unloading the traction device. Due to the mirrored geometry of the top and bottom load blocks (i.e., friction block 104 and follower 142), the friction element does not generate undesirable moments around the faces of the friction element that would cause the wedge to tilt, thereby eliminating, minimizing, or otherwise reducing the risk of "stick-slip" of the friction element in the traction device.

[0065] Dual friction traction device assembly 100 as described herein may be used in any field utilizing Coulomb friction damping where performance is degraded by "stick-slip." Embodiments may also be used in suspension damping.

[0066] Embodiments of the present disclosure provide a dual friction traction device assembly 100 that eliminates, minimizes, or otherwise reduces the potential for stick-slip.

[0067] Although various spatial and directional terms such as top, bottom, lower, middle, lateral, horizontal, vertical, front, etc. may be used to describe the embodiments of the present disclosure, it should be understood that these terms are used only with respect to the orientations shown in the figures. The orientation may be reversed, rotated, or otherwise changed so that the upper part becomes the lower part, the lower part becomes the upper part, the horizontal becomes vertical, etc.

[0068] As used herein, a structure, limitation, or element "configured to" perform a task or operation is specifically structurally formed, constructed, or adapted in a manner corresponding to the task or operation. For clarity and avoidance of doubt, an object that is merely capable of being modified to perform a task or operation is not "configured to" perform a task or operation as used herein.

[0069] It should be understood that the above description is intended to be illustrative, not restrictive. For example, the above embodiments (and / or aspects thereof) can be used in combination with each other. In addition, many modifications can be made without departing from the scope of the present disclosure to adapt specific situations or materials to the teachings of the various embodiments of the present disclosure. Although the size and type of the materials described herein are intended to limit the parameters of the various embodiments of the present disclosure, the embodiments are by no means restrictive and are exemplary embodiments. After reading the above description, many other embodiments will be apparent to those skilled in the art. Therefore, the scope of the various embodiments of the present disclosure should be determined with reference to the appended claims and the full scope of the equivalents of the rights granted by these claims. In the appended claims, the terms "including" and "wherein" are used as the plain English equivalents of the corresponding terms "including" and "wherein". In addition, the terms "first", "second" and "third", etc. are used only as labels and are not intended to impose numerical requirements on their objects. In addition, the limitations of the following claims are not written in the form of device plus function and are not intended to be understood according to 35 U.S.C. § 112 (f), unless and until such claim limitations explicitly use the term "member for..." followed by a functional statement without other structures.

[0070] This written description uses examples to disclose various embodiments of the present disclosure, including the best mode, and also enables any person skilled in the art to practice the various embodiments of the present disclosure, including making and using any device or system and performing any included method. The patent scope of the various embodiments of the present disclosure is defined by the claims, and may include other examples that occur to a person skilled in the art. If an example has structural elements that do not differ from the literal language of the claims, or if an example includes equivalent structural elements that do not differ substantially from the literal language of the claims, such other examples are intended to be within the scope of the claims.

Claims

1. A double friction traction device assembly for a carriage connection system of a railway carriage, the double friction traction device assembly comprising: a housing having an interior chamber; one or more friction shoes disposed within the interior chamber; a first load block providing a first angled interface with the one or more friction shoes; a second load block providing a second angled interface with the one or more friction shoes; and A spring pack is disposed within the interior chamber between the base of the housing and the second load block, wherein the spring pack includes a series of elastomeric pads and metal plates.

2. The dual friction traction device assembly according to claim 1, wherein: The first angled intersection surface is a mirror image of the second angled intersection surface.

3. The dual friction traction device assembly according to claim 1, wherein: The one or more friction shoes are disposed between the first load block and the second load block.

4. The dual friction traction device assembly according to claim 1, wherein: At least a portion of the first load mass and at least a portion of the second load mass are located within the interior chamber of the housing.

5. The dual friction traction device assembly according to claim 1, wherein: The one or more friction shoes include three friction shoes.

6. The dual friction traction device assembly according to claim 1, wherein: The first angled interface includes a first angled surface of the one or more friction shoes that abuts a second angled surface of the first load block.

7. The dual friction traction device assembly according to claim 6, wherein: The second angled interface includes a third angled surface of the one or more friction shoes that abuts a fourth angled surface of the second load block.

8. The dual friction traction device assembly according to claim 1, wherein: The first load block and the second load block are coaxial with the housing.

9. The dual friction traction device assembly according to claim 1, wherein: The one or more friction shoes are spaced apart from a central longitudinal axis of the housing.

10. The dual friction traction device assembly according to claim 1, wherein: The second load block comprises: abutting against the expanded end of the spring assembly; a reduced end opposite the expanded end, the reduced end disposed within a space associated with the one or more friction shoes; and An angled wall that converges toward the reduced end, wherein the angled wall abuts an angled lower surface of the one or more friction shoes.

11. The dual friction traction device assembly according to claim 10, wherein: The one or more friction shoes also include an angled upper surface that abuts the angled lower surface of the first load block.

12. A method of forming a dual friction hitch assembly for a car coupling system of a rail car, the method comprising: disposing one or more friction shoes in the interior chamber of the housing; providing a first angled interface between the first load block and the one or more friction shoes; providing a second angled interface between the second load block and the one or more friction shoes; as well as A spring pack is disposed within the interior chamber between a base of the housing and the second load block, wherein the spring pack includes a series of elastomeric pads and metal plates.

13. The method according to claim 12, wherein: The method also includes mirroring the first angled interface and the second angled interface.

14. The method according to claim 12, wherein: The method also includes positioning the one or more friction shoes between the first load block and the second load block.

15. The method according to claim 12, wherein: The method also includes disposing at least a portion of the first load mass and at least a portion of the second load mass within the interior chamber of the housing.

16. The method according to claim 12, wherein: Providing a first angled interface includes abutting a first angled surface of the one or more friction shoes against a second angled surface of the first load block.

17. The method according to claim 16, wherein: Providing a second angled surface includes abutting a third angled surface of the one or more friction shoes against a fourth angled surface of the second load block.

18. The method according to claim 12, wherein: The method also includes coaxially aligning the first load block and the second load block with the housing.

19. The method according to claim 12, wherein: The method also includes radially spacing the one or more friction shoes from a central longitudinal axis of the housing.

20. A dual friction traction device assembly for a carriage coupling system of a railway carriage, the dual friction traction device assembly comprising: a housing having an interior chamber; one or more friction shoes disposed within the interior chamber; a first load block providing a first angled interface with the one or more friction shoes; a second load block providing a second angled interface with the one or more friction shoes; a spring assembly disposed within the interior chamber between a base of the housing and the second load block, wherein the spring assembly includes a series of elastomeric pads and metal plates, wherein the first angled intersection surface is a mirror image of the second angled intersection surface; wherein the one or more friction shoes are disposed between the first load block and the second load block; Wherein, at least a portion of the first load block and at least a portion of the second load block are within the inner chamber of the housing.

Images