SE2250285A1 - Coupler for a railway vehicle with a biasing device, and method for overhauling a coupler - Google Patents

Abstract

The present invention relates to a coupler for a railway vehicle, the coupler comprisinga front portion (20) comprising a coupler head (21),a rear portion (30) comprising a mounting structure (31) for mounting on a railway vehicle,a coupler shank (26) comprising a through hole (27) having a first width (wi), the coupler shank (26) being arranged on a pin (32) extending through the through hole (27) and the pin (32) having a second width (w2) that is smaller than the first width (wi) of the through hole (27),wherein one of the coupler shank (26) and the pin (32) is connected to the coupler head (21) of the front portion (20) and the other of the coupler shank (26) and the pin (32) is connected to the mounting structure (31) of the rear portion (30),and wherein the coupler (10) further comprises a biasing device (40) arranged in the through hole (27) of the coupler shank (26), the biasing device (40) being configured to bias the pin (32) to one side of the through hole (27).

Description

COUPLER FOR A RAILWAY VEHICLE WITH A BIASING DEVICE, AND METHOD FOR OVERHAULING A COUPLER TECHNICAL FIELD The present invention relates to a coupler for a railway vehicle having a coupler shank connected to a pin eXtending through a through hole of the coupler shank for providing a pivotable connection. The invention also relates to a method for overhauling a coupler. BACKGROUND Railway couplers generally comprise a rear end for mounting on a railway vehicle and a front end with a coupler head for coupling to a similar coupler. The front end and the rear end are typically pivotably connected to each other in order to allow the front end to swivel in relation to the rear end during operation of a train set. One way of establishing the pivotable connection is by arranging a pin in a through hole in a coupler shank so that the coupler shank is able to pivot in relation to the pin.

When coupling the coupler head of the front end of a coupler, the coupler is brought into connection with a similar coupler with a large enough force that hook plates of the coupler heads of the respective couplers are rotated so that the coupling may be established by link pins of each coupler head being trapped by the hook plate of the other. The hook plate of each coupler is biased towards a coupled state, typically with a mechanical spring.

When uncoupling the coupler head, an uncoupling handle is turned to force the hook plates to rotate and release the link pins. However, often the manual use of the uncoupling handle of one of the couplers is insuff1cient to cause the desired rotation. This may be resolved by using the uncoupling handles of both couplers simultaneously, but this solution is cumbersome and requires two operators to be on site.

There is therefore a need for an improvement in railway couplers that ensures that uncoupling can take place in a reliable and convenient way without requiring two operators.

SUMMARY The object of the present invention is to eliminate or at least to minimize the problems discussed above. This is achieved by a coupler and by a method for overhauling a coupler according to the appended independent claims. The coupler of the present invention comprises a front portion comprising a coupler head, a rear portion comprising a mounting structure for mounting on a railway vehicle, a coupler shank comprising a through hole having a first Width, the coupler shank being pivotably arranged on a pin eXtending through the through hole and the pin having a second Width that is smaller than the first Width of the through hole, Wherein one of the coupler shank and the pin is connected to the coupler head of the front portion and the other of the coupler shank and the pin is connected to the mounting structure of the rear portion.

Also, the coupler further comprises a biasing device arranged in the through hole of the coupler shank, the biasing device being configured to bias the pin to one side of the through hole.

By providing the biasing device to bias the pin to a side of the through hole, the pin is prevented from moving in the through hole, and this ensures that an uncoupling force applied to the coupler head Will cause uncoupling of the coupler head rather than cause a movement of the coupler shank in relation to the pin.

Suitably, the coupler head comprises a hook plate that is biased towards a coupled state, and a biasing device force of the biasing device on the pin is larger than a hook plate spring force on the hook plate. This is advantageous in ensuring that a force applied to the coupler head Will cause rotation of the hook plate before it causes movement of the coupler shank in relation to the pin.

In some embodiments, the biasing device comprises a mechanical spring configured to act on the pin With the biasing device force. Thereby, a convenient and reliable biasing device is achieved With a long lifetime and low risk of malfunction due to Wear.

Also, the biasing device may comprise a device head and the mechanical spring may be configured to push the device head towards the pin. Also, the biasing device may comprise a guide pin for aligning the biasing device With a guide opening in the through hole of the shank. Thereby, the biasing device is held in place in a reliable and convenient Way to ensure that the biasing force on the pin remains in a desired direction regardless of additional forces or vibrations that occur during operation of a railway vehicle on Which the coupler is mounted.

In embodiments comprising a guide pin, the guide pin suitably comprises a threaded portion and the biasing device may further comprise a nut for cooperating With the threaded portion of the guide pin for pre-tensioning the mechanical spring of biasing device. Thereby, the bias on the pin is set and the magnitude of the biasing force may be selected by adjusting the nut in relation to the threaded portion.

Also, the coupler of the invention may comprise at least one mounting portion for mounting the biasing device on the shank. Thereby, the biasing device is securely fastened to the shank and a desired position of the biasing device may be maintained during operation.

The present invention also relates to a method for overhauling a coupler, Wherein the method comprises - providing a coupler according to the invention, - removing the biasing device from the coupler, and - mounting a replacement biasing device in the through hole of the coupler.

By replacing the biasing device, the lifetime of the coupler is extended and it is also ensured that the desired biasing force on the pin is maintained for a prolonged period of time so that uncoupling of the coupler can always take place when desired.

Suitably, the method for overhauling the coupler comprises removing a mechanical spring from the biasing device and mounting a replacement mechanical spring in the biasing device to create the replacement biasing device. Thereby, the replacement biasing device can be made by simply replacing the mechanical spring of the biasing device previously used in the coupler. This is advantageous both in being a fast and efficient way of creating the replacement biasing device and in being cost efficient since only one component needs replacing.

Alternatively, the replacement biasing device may be a separate biasing device that is similar to the biasing device previously used so that the entire biasing device is replaced during overhaul.

Suitably, the method for overhauling the coupler comprises pre-tensioning the replacement biasing device. Thereby, the biasing device force of the biasing device is created by pre-tensioning the replacement biasing device during the overhaul. This also has the benefit of adjusting the biasing device force so that the magnitude of the force may be changed during overhaul. In this way, the magnitude of the force may be kept at the same level as before overhaul or may be greater or smaller depending on what is deemed suitable. One factor that may be taken into account is the hook plate spring force of the coupler, since it is a particular benefit when the biasing device force is larger than the hook plate spring force.

Many additional benefits and advantages of the present invention will be readily understood by the skilled person in view of the detailed description below. DRAWINGS The invention will now be described in more detail with reference to the appended drawings, wherein Fig. 1 discloses a perspective view of a coupler according to an embodiment of the invention; Fig. 2 discloses a coupler shank of the coupler of Fig. 1 in a view from above; Fig. 3 discloses a cross-sectional view of the coupler shank, pin and biasing device of the coupler of Fig. 1; Fig. 4a discloses a view from above of the coupler head of the coupler of Fig. 1 in an uncoupled state; Fig. 4b discloses a cross-sectional view from above of a coupler head of the coupler of Fig. 1 in a coupled state with a similar coupler; Fig. 5a discloses a view from the side of a biasing device according to the invention; Fig. 5b discloses a cross-sectional view from the side of the biasing device of Fig. 5a; and Fig. 6 discloses schematically a method for overhauling a coupler according to the invention.

All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate the respective embodiments, whereas other parts may be omitted or merely suggested. Any reference number appearing in multiple drawings refers to the same object or feature throughout the drawings, unless otherwise indicated. DETAILED DESCRIPTION Fig. 1 discloses a coupler according to a first embodiment of the present invention, comprising a front portion 20 with a coupler head 21. The coupler head 21 comprises a hook plate 22 with a link pin 23 and an opening 24 for receiving a link pin of a similar coupler (see Fig. 4).

The front portion 20 further comprises a coupler shank 26 that is connected to or integrated with the coupler head 21. In the coupler shank 26, there is a through hole 27 for receiving a pin 32 that is arranged on, integrated with or connected to a rear portion 30 of the coupler 10. The rear portion 30 comprises a mounting structure 31 for mounting the coupler on a railway vehicle (not shown) as is well known within the art, and suitably also comprises draft gear 33 for damping and/ or buffering draft and buff forces during operation.

The coupler shank 26 is pivotably arranged on the pin 32, and this is to be understood as the pin extending through the through hole 27 so that the coupler shank 26 is pivotable around a center of rotation that coincides with the pin 32. Suitably, a longitudinal axis of the pin 32 and a longitudinal aXis of the coupler shank 26 is substantially perpendicular when the coupler 10 is in a rest position. The rest position may be an uncoupled state or a state where the coupler is coupled but stationary, or both. During use, the coupler shank 26 may pivot around a vertical aXis that is parallel or coinciding with the longitudinal axis of the pin 32, and the coupler shank 26 may also pivot around a horizontal axis that is perpendicular to both the longitudinal axis of the coupler shank 26 and the longitudinal axis of the pin 32.

Fig. 2 discloses the coupler shank 26 of the front portion 20 seen from above, with the through hole 27 having a first width w1. In the through hole, a biasing device 40 is mounted on the coupler shank 26 by a mounting portion 45 that may suitably comprise a mounting bracket or mounting plate 46 that is fixedly attached to the coupler shank 26 by fasteners 29 such as bolts or screws.

Fig. 3 discloses the coupler shank 26 of the front portion 20 pivotably connected to the rear portion 30 by the pin 32 extending through the through hole 27. The pin 32 is held by a pin holder 33 of the rear portion 30. The pin 32 itself has a second width wg that is smaller than the first width w1 of the through hole 27 to facilitate pivoting of the front portion 20 in relation to the rear portion 30. As also shown in Fig. 3, the biasing device 40 is arranged in the through hole 27 so that it biases the pin 32 to one side 27A of the through hole 27. This reduces a free stroke of the front portion 20 in relation to the rear portion 30 and facilitates uncoupling of the coupler 10 by preventing the uncoupling force from resulting in a movement of the front portion 20 in relation to the rear portion 30 so that the mechanical uncoupling itself may take place instead.

The biasing device 40 is arranged on a guide pin 43 that extends through a guide opening 28 in the coupler shank 26 such that alignment of the biasing device 40 may be maintained during operation regardless of loads and vibrations, and thus maintaining the force on the pin 32 in a desired direction towards the one side 27A of the through hole 27. The one side 27A is in the first embodiment a rear side, i.e. a side closer to the rear portion 30 than to the front portion 20 of the coupler 10. However, in other embodiments the one side 27A may instead be another side of the through hole 27 such as a front side or any other side. Thus, the biasing device 40 is configured to bias the pin 32 by pushing against the pin 32.

The biasing device 40 in the first embodiment also comprises a mechanical spring 41, a device head 42 for contacting the pin 32 and also a nut 44 for adjusting pre-tension of the mechanical spring 41. This will be explained in more detail below with reference to Fig. 5a-5b.

In the first embodiment, the front portion 20 comprises the coupler shank 26 and the rear portion 30 comprises the pin 32, but it is to be noted that in other embodiments the pin 32 could instead be comprised in the front portion 20 and the coupler shank 26 in the rear portion 30. An advantage of including the coupler shank 26 in the front portion 20 is that a swing radius of the coupler head 21 in relation to the rear portion 30 is improved due to the distance from the coupler head 21 to the pin 32.

Fig. 4a shows the coupler head 21 in an uncoupled state with the link pin 23 extending from the coupler head 21 ready to be coupled to a similar coupler 10' (see Fig. 4b). The coupler head 21 further comprises a hook plate spring 25 connected to the hook plate 22 and to the coupler head 21 and configured to bias the hook plate 22 towards the coupled state, i.e. in a counter-clockwise direction in Fig. 4a. contact with the opening 24 of the hook plate 22, the hook plate 22 is activated When a link pin of a similar coupler is brought into and rotates towards the coupled state due to the bias from the hook plate spring 25.

Fig. 4b shows the coupler head 21 in a coupled state with a similar coupler 10'. Similar parts of the couplers 10, 10' are denoted with the same reference numeral and with a prime, ', for components of the similar coupler 10'.

Coupling of the two couplers 10, 10' takes place by the link pin 23 of the hook plate 21 entering a similar opening 24' of a similar hook plate 22' of the similar coupler 10' to create a contact between them, while at the same time a link pin 23' of the similar hook plate 22' enters the opening 24 of the hook plate 22 of the coupler head 21 of the coupler 10 according to the present invention. This contact causes the hook plate 22 to rotate, trapping the link pin 23' of the similar coupler 10' to create a mechanical coupling between them.

Since the hook plate spring 25 is arranged between the hook plate 22 and the coupler head 21 to bias the hook plate 22 in the coupled direction, the uncoupling requires rotation of the hook plate 22 by turning an uncoupling handle 22A to counteract the hook plate spring force HF and release the link pin 23' of the similar coupler 10'. Due to the biasing device 40 provided to bias the pin 32 and prevent movement of the coupler shank 26 in relation to the pin 32 when the uncoupling handle 22A is turned, using the uncoupling handle 22A results in rotation of both the hook plate 22 of the coupler 10 and of the hook plate 22' of the similar coupler 10' so that both link pins 23, 23' are released. Rotating the hook plate 22 thus forces the rotation of the similar hook plate 22' due to the contact of the link pin 23 with the similar opening 24' and of the similar link pin 23' with the opening 24.

The hook plate spring 25 thus creates a biasing force on the hook plate 22 and said biasing force is in the following referred to as a hook plate spring force HF. Similarly, the biasing device 40 creates a biasing force on the pin 32 that will be referred to as a biasing device force BF. In order to rotate the hook plate 22 and create the mechanical uncoupling, an uncoupling force on the hook plate of a magnitude larger than the hook plate spring force HF is required.

In the coupler 10 of the first embodiment, the biasing device force BF is larger than the hook plate spring force HF to ensure that the uncoupling force on the coupler head 21 causes the rotation of the hook plate 22. In other embodiments, the relationship between the biasing device force BF and the hook plate spring force HF could instead be reversed or they could be equal, since the main advantage of the present invention, i.e. reducing the risk of the uncoupling not succeeding due to the uncoupling force being absorbed as a movement of the coupler shank 26 in relation to the pin 32, is achieved as long as there is a biasing device force BF on the pin 32.

Fig. 5a-5b disclose the biasing device 40 in more detail, showing the guide pin 43 and the nut 44 as well as the mechanical spring 41 and the device head 42. The mechanical spring 41 is suitably a volute spring that has the advantages of being a resilient mechanical spring with low risk of failure and long lifetime, and at the same time being able to create a large load and long compression in a small space. Other mechanical springs 41 are of course also possible within the scope of the invention, and such alternatives that also have the benefits of being sturdy with long lifetime and low risk of failure are helical or coil springs, or compression springs in general.

The device head 42 is mounted on, connected to or integrated with the mechanical spring 41 and is thereby configured to be pushed against the pin 32 when the biasing device 40 is mounted in place in the through hole 27. The biasing device 40 may also comprise a back plate 46 so that the mechanical spring 41 is arranged between the device head 42 and the back plate 46.

Suitably, the guide pin 43 comprises a threaded portion 47 that is able to cooperate with a thread of the nut 44 so that the nut 44 can be screwed along the guide pin 43. In this way, the mechanical spring 41 can be pre-tensioned to a desired load in order to create the biasing device force BF by the guide pin 43 being pulled to the left-hand side of Fig. 5b. Due to the interaction of the guide pin 43 and the nut 44, the pre-tensioning of the biasing device 40 is maintained even when the biasing device 40 is subjected to additional loads from the guide pin 32 pushing against the device head 42 during use and when the coupler 10 is subjected to vibrations during operation of the coupler 9 . Thus, the guide pin 43 serves to both align the biasing device 40 With the guide pin 32 to ensure that the biasing device force BF is applied in a desired place and direction, and also to create the pre-tension of the mechanical spring 41 .

The method for overhauling the coupler of the invention Will now be described With reference to Fig. 6, Where optional features are indicated by dashed boxes. For the purposes of this invention, overhaul is defined as any repair or maintenance that takes place on a coupler.

When overhauling the coupler 10, the method comprises providing 101 the coupler 10 of the invention according to any of the embodiments disclosed herein. The biasing device 40 is removed 102 and a replacement biasing device 40' is mounted 103 in the through hole 27 of the coupler 10. The replacement biasing device 40' comprises the features of the biasing device 40 according to any embodiment of the present invention.

In some embodiments, the replacement biasing device 40' is created by replacing the mechanical spring 41 of the biasing device 40 With a replacement mechanical spring 41'. If suitable, other components of the biasing device 40 may also be replaced and this is advantageous Where it is determined that there is Wear on such components so that operation of the biasing device 40 is decreased. HoWever, in many cases it Will be sufficient to replace only the mechanical spring 41.

In other embodiments, the replacement biasing device 40' is a fresh biasing device that does not include any part of the previously used biasing device 40.

When mounting 103 the replacement biasing device 40', the overhaul may comprise pre-tensioning 105 the replacement biasing device 40'. The pre- tensioning 105 may be to create a biasing device force BF that is of the same magnitude as the biasing device force BF of the previously used biasing device 40, but optionally the magnitude may be changed to be lower than before or higher than before. Pre-tensioning 105 the replacement biasing device 40' may take place during mounting 103 or after mounting 103.

It is to be noted that features from the various embodiments described herein may freely be combined, unless it is explicitly stated that such a combination Would be unsuitable.

Claims (8)

Claims

1. Coupler for a railway vehicle, the coupler comprising a front portion (20) comprising a coupler head (21), a rear portion (30) comprising a mounting structure (31) for mounting on a railway vehicle, a coupler shank (26) comprising a through hole (27) having a first width (w1), the coupler shank (26) being pivotably arranged on a pin (32) extending through the through hole (27) and the pin (32) having a second width (wg) that is smaller than the first width (w1) of the through hole (27), wherein one of the coupler shank (26) and the pin (32) is connected to the coupler head (21) of the front portion (20) and the other of the coupler shank (26) and the pin (32) is connected to the mounting structure (31) of the rear portion (30), and wherein the coupler (10) further comprises a biasing device (40) arranged in the through hole (27) of the coupler shank (26), the biasing device (40) being configured to bias the pin (32) to one side of the through hole (27). . Coupler according to claim 1, wherein the coupler head (20) comprises a hook plate (22) that is biased towards an uncoupled state with a hook plate spring force (HF), and wherein a biasing device force (BF) of the biasing device (40) on the pin (32) is larger than the hook plate spring force (HF) on the hook plate (22). . Coupler according to claim 1 or 2, wherein the biasing device (40) comprises a mechanical spring (41) configured to act on the pin (32) with the biasing device force (BF).4. Coupler according to claim 3, Wherein the biasing device (40) comprises a device head (42) and the mechanical spring (41) is configured to push the device head (42) towards the pin (32), and Wherein the biasing device (40) further comprises a guide pin (43) for aligning the biasing device (40) With a guide opening (28) in the through hole (27) of the shank (26). . Coupler according to claim 4, Wherein the guide pin (43) comprises a threaded portion (47) and Wherein the biasing device (40) further comprises a nut (44) for cooperating With the threaded portion (47) of the guide pin (43) for pre-tensioning the mechanical spring (41) of the biasing device (40). . Coupler according to any previous claim, further comprising at least one mounting portion (45) for mounting the biasing device (40) on the coupler shank (26). . Method for overhauling a coupler for a railway vehicle, the method comprising - providing (101) a coupler according to any of claims 1-6, - removing (102) the biasing device (40) from the coupler, and - mounting (103) a replacement biasing device (40') in the through hole (27) of the coupler (10). . Method according to claim 7, further comprising removing (104) a mechanical spring (41) from the biasing device (40) and mounting a replacement mechanical spring (41') in the biasing device (40) to create the replacement biasing device (40'). . Method according to claim 7 or 8, further comprising pre-tensioning (105) the replacement biasing device (40'). 13