WO2012026865A1

WO2012026865A1 - A centering device for a pivoted draftgear, particularly in an automatic coupler for a rail vehicle

Info

Publication number: WO2012026865A1
Application number: PCT/SE2011/050983
Authority: WO
Inventors: Anders Westman; Mattias Hjort
Original assignee: Ego International B.V.
Priority date: 2010-08-25
Filing date: 2011-08-09
Publication date: 2012-03-01
Also published as: SE535148C2; SE1050871A1

Abstract

A centering device for a draftgear pivoted to a vehicle chassis is disclosed, particularly a centering device in an automatic coupler for a rail vehicle, which centering device is effective to hold the draftgear in a centered position for coupling, comprising a first and a second push rod (6, 7), which run separated side by side under the draftgear, and which push rods, by their front ends, support the draftgear from below. The centering device is characterized in that the push rods (6, 7) are assigned a torsion bar (8) that is effective to elastically hold the push rods in a supporting position.

Description

TITLE

A centering device for a pivoted draftgear, particularly in an automatic coupler for a rail vehicle TECHNICAL FIELD OF THE INVENTION

The present invention relates to a centering device for a draftgear pivoted to a vehicle chassis, particularly in an automatic coupler for a rail vehicle, which centering device is effective to hold the draftgear in a position centered and aligned for coupling.

BACKGROUND AND PRIOR ART

Automatic coupling of railroad cars and locomotives presupposes that the coupling draftgears are correctly aligned with each other, and essentially centered in the horizontal and vertical direction. Some deviation from an absolute centering can be tolerated and corrected upon coupling by a guide cone carried in the front plate of the draftgear. In order to force the individual draftgear to assume a suitable position for coupling, some form of centering device is usually arranged to carry the draftgear from below and hold the same in a neutral or centered position. Such centering devices are typically resilient to present the draftgear a certain required mobility vertically and laterally. Therefore, the centering device typically consists of a spring-loaded arm, which by its front end supports the draftgear from below and, in its rear end, is pivotally attached in the vehicle chassis or in the bearing bracket including a swivel joint by which the draftgear is pivotally attached to the vehicle chassis.

A disadvantage of known constructions is that they imply added weight of the draftgear. Another disadvantage of compression spring-biased coupler centering devices is that the elasticity of the spring may get weak over time and require replacement.

SUMMARY OF THE INVENTION

The invention generally aims at providing a coupler centering device that to a decreased extent adds weight to the draftgear. Furthermore, the invention aims at providing a coupler centering device the bias of which in the supporting position can be regulated. Another object of the invention is to provide a coupler centering device of a simplified design having a minimal number of movable parts and that requires a minimal effort of maintenance. At least the overall object is fulfilled by a centering device of the type indicated by way of introduction, which comprises a first and a second push rod that run separated side by side under the draftgear, and which push rods, by their front ends, support the draftgear from below, wherein the push rods are assigned a torsion bar that is effective to elastically hold the push rods in a supporting position.

The utilization of one or more torsion bars as force members provides a

mechanically simple design of low weight. Torsion bars may be realised in the form of conventionally constructed leaf spring packages, or in the form of homogeneous rods manufactured from spring steel.

For the object of the invention, preferably one or two torsion bars are utilized, which are arranged in a lying or upright position. The torsion bars may more precisely be arranged to extend horizontally or vertically, or be arranged with another inclined orientation. The torsion bars may furthermore be arranged to extend in a plane transverse to the longitudinal axis of the vehicle chassis, or arranged in a plane intersecting the longitudinal axis at another oblique angle. In the case of two or more torsion bars, these may alternatively be arranged to extend in different planes. In the case of a lying torsion bar, the push rods may be directly non-turnably coupled to the torsion bar, if the drawbar rests slidingly and mechanically guided in the front ends of the push rods. In this case, a laterally acting torque against the drawbar can be provided by the individual push rod in itself being realised in the form of a laterally resilient element, for instance in the form of a leaf spring or a leaf spring package.

In the case of a standing torsion bar, an interconnected link is required, which converts the motion and turning of the push rod around a lying axis into a turning around a standing axis of the torsion bar. In this case, the link also forms a torque arm that, via an inherently stiff push rod, serves to apply a laterally directed torque to the drawbar. In both cases, an interconnected link may meritoriously provide a conversion of the push rod motion into a turning adapted to the strength and elasticity of the torsion bar. Therefore, in a preferred embodiment, the push rods are acted upon by the torsion bars via a respective link arm that is connected with a rear end of the push rod in question. In that connection, the link arm is pivotally connected with the push rod, preferably by means of a ball-and-socket joint that allows universal motion in the joint.

In a particularly preferred embodiment, the link arms connected with the push rods are assigned a deflection limiter that forms an end position of the swinging of the link arms, thereby determining the position of the push rods in the centered position of the draftgear. In this way, the push rods may be biased toward the centered position by setting of the angle position of the torsion bars in the end position of the link arms. Said deflection limiter may be adjustable and influence the orientation of the draftgear in a vertical plane.

The link arm connected with the push rod may be non-turnably coupled to the torsion bar for direct bias of the push rod.

Alternatively, the link arm connected with the push rod may be made in the form of a lever that is hinged in a fulcrum and acted upon by a rocker arm non-turnably coupled to the torsion bar for indirect bias of the push rod. In this embodiment, an adaptation of the motion and load of the push rod to the properties of the selected torsion bar can be provided.

In this alternative embodiment, the lever may comprise a freely rotating roller that presses against a rolling path formed on the rocker arm of the torsion bar. Said rolling path may be angled or curved for a non-linear and more or less progressive alteration of the force of the torsion bar depending on the angle position of the link arm and the position of the roller on the rolling path. By the first measure, friction losses are reduced in the contact between the lever and the rocker arm, and by the second measure, further possibility of maximally utilizing the strength and elasticity of the torsion bar is provided. For space reasons, it may be preferred that the torsion bars extend in an upright orientation. In a fundamental embodiment of the solution, the torsion bars are in that connection non-turnably anchored in their upper ends. In a further developed embodiment, the torsion bars may be turnably mounted in relation to the vehicle chassis but non-turnably coupled to a respective arm, and mutually connected by a stay coupled between the arms. By this measure, a simplified installation of the torsion bars on the bearing bracket or to the vehicle chassis is achieved. The embodiment may entail a certain stress-relief of the torsion bars upon lateral swinging of the draftgear, such as in cornering. In addition, it is achieved that the restoring/ lifting force of the torsion bars immediately is available for both push rods in case the draftgear falls below the desired and neutral vertical position. Particularly, it is foreseen an embodiment wherein the torsion bars are mutually connected by an interconnected stay of an adjustable length by which the bias of the torsion bars can be regulated. In this way, the bias can be readjusted and adapted to changes and retrofittings in the draftgear. The torsion bars are suitably arranged one on each side of the swivel joint by which the draft device is coupleable to a vehicle chassis. In the case of lying torsion bars, these may be suspended in brackets that are attached in the foremost cross beam of the vehicle chassis or on the bearing bracket in which the swivel joint is journalled. It is also feasible an embodiment wherein a single and lying torsion bar extends through the bearing bracket, between the bearing of the drawbar in the bearing bracket and the attachment of the bearing bracket to the vehicle chassis. In the case of standing torsion bars, these may advantageously be journalled in brackets or the like that are carried on the bearing bracket. In the latter case, the link arms pivotally connected with the push rods may intersect each other below the bearing bracket and be acted upon by the respective torsion bar that is situated on the opposite side of the swivel joint. In this way, in addition to a longer torque arm, also an extraordinarily compact and space-saving design is achieved with a retained possibility of adapting the movement of the push rods to the properties of the torsion bar.

In a particularly compact embodiment, standing torsion bars may be arranged to extend in parallel through the swivel joint of the draft device, and more precisely arranged to run in through drillings arranged on opposite sides of the centre of the swivel joint. Herein, it is included that the torsion bars may be arranged on both sides of the longitudinal axis of the vehicle chassis or on the longitudinal axis, and preferably in diametrically opposite positions on each side of the centre of the swivel joint.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiment examples of the invention are explained in more detail below, reference being made to accompanying schematic drawings, of which

Fig. 1 shows a first simplified embodiment of the coupler centering device in a side view;

Fig. 2 shows a second embodiment in a corresponding side view;

Fig. 3 shows a third embodiment in a corresponding side view;

Fig. 4 shows the third embodiment in a view from below; Fig. 5 shows an alternative embodiment of the connection of the torsion bars with push rods included in the coupler centering device in a view from below;

Fig. 6 shows an embodiment of the mutual connection of the torsion bars in a view from above;

Fig. 7 shows an alternative embodiment of the bearing of the torsion bars in the draftgear in a view from below;

Fig. 8 shows a modified embodiment of the coupler centering device in a view from below;

Fig. 9 shows a modified embodiment of the coupler centering device in a view from above, and Fig. 10 shows a preferred embodiment of the coupler centering device in a perspective view. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT EXAMPLES ILLUSTRATED IN THE DRAWINGS

Initially, it should be explained that the reference numeral 1 henceforth is used to generally denote a draftgear comprising a drawbar 2, which, in its front end

(directed toward the left in the drawing figures), usually carries a coupler head (not shown) and, in its rear end, is pivotally attached to the front cross beam 3 of a vehicle chassis by means of a swivel joint 4 that is mounted in a bearing bracket designated 5. The swivel joint typically comprises a shaft by which the draftgear 1 is pivotally arranged in the horizontal direction and to a certain extent also in the vertical direction.

In order to enable automatic coupling to a meeting draftgear, a coupler centering device is arranged to support the draftgear from below and hold the same in a centered neutral position for coupling.

The coupler centering device comprises a pair of push rods 6 and 7 (only the push rod 6 of which is visible in side view), which run side by side under the drawbar and on the front ends of which the draftgear rests. Suitably, the push rods run divergingly toward their rear ends to exert a lateral force component against the draftgear.

The push rods 6, 7 are held resiliently in the supporting position by means of an elastic force member. Fig. 1 shows a strongly simplified and illustrative embodiment of the invention, according to which the force member comprises at least one torsion bar 8 having a lying orientation. Alternatively, each one of the push rods may be assigned a respective torsion bar 8 and 9, only the torsion bar 8 of which is visible in side view. The torsion bar 8 is non-turnably anchored in the cross beam 3 of the vehicle chassis or in the bearing bracket 5, and extends from its anchor point to an end, which is turnably mounted in a bracket 10, but non-turnably coupled to the rear end of the push rod 6, 7 in question. In the embodiment according to Fig. 1 , the draftgear is floatingly carried by a resilient push rod, and rests in a sliding pressure point 1 1 on the front end of the push rod. It will be appreciated that a downwardly directed movement of the draftgear causes a turning of the push rod and of the torsion bar around the centre of the torsion bar, which is counteracted by the inherent torsional stiffness of the torsion bar. In this simplified embodiment, the push rods 6, 7 may consist of laterally resilient elements that apply a lateral torque to the drawbar so as to enable centering of the same laterally. In order to counteract swinging of the draftgear in the embodiment of Fig. 1 , the coupler centering device may comprise a swinging or shock absorber, not shown in more detail, which may be arranged to act against the push rod 6 or against the drawbar 2. For the same purpose, but also to determine the angle position of the push rod and torsion bar in the neutral position of the draftgear, deflection limiter 12 and/ or 13 may be arranged on the drawbar 2 and on the bracket 10,

respectively. The deflection limiter 12/ 13 allows the torsion bar to be biased toward the deflection limiter by turning of the torsion bar in its anchor point. In this way, a threshold value of the load required to move the draftgear downward from the neutral vertical position can be set.

The embodiment of Fig. 2 differs from the above in the respect that the push rod 6 comprises a section 15 that starts from a knee 14 and extends at an angle from the push rod 6 and in its other end is non-turnably coupled to the torsion bar 8. In this embodiment, the lying torsion bar 8 may be moved up to a higher level, and may alternatively also extend through the bearing bracket 5, in a space-saving design.

An inherently stiff push rod 6 may, in the embodiment according to Fig. 2, be pivotally coupled to the drawbar, and, via a swivel joint arranged in the knee 14, pivo tally coupled to the section 15, which in this way is a link arm 15 pivotally connected with the push rod between the push rod 6 and the torsion bar 8. In the motion laterally of the drawbar, the individually loaded push rods 6, 7 of this embodiment provide a laterally directed torque that aims to restore the drawbar to a laterally centered initial position. Figs. 3 and 4 show an embodiment wherein the torsion bar 8 extends upright beside the bearing bracket 5. The torsion bar 8 is non-turnably anchored in its upper end in an appropriate bracket 16, which may be attached to the cross beam 3 of the vehicle chassis or to the bearing bracket 5. The lower end of the torsion bar 8 is turnably mounted in an opposite bracket 17, but non-turnably connected with a link arm 18 that in its other end is pivotally connected with the rear end of the push rod 6. The torsion bar 9 is arranged in a corresponding way on the opposite side of the bearing bracket. In the embodiment according to Figs. 3 and 4, the draftgear rests stationary against the front end of the push rod, at least in the sense that the push rod is prevented from moving forward in relation to the drawbar in the longitudinal direction of the drawbar. For the purpose, a stop lug is arranged on the underside of the drawbar. Alternatively, the push rod may, in a known way per se, have a pin that engages a support block 19 mounted on the underside of the drawbar, the pin being slidably mounted in the support block in front of a sliding stop formed on the push rod in question. In the swinging of the draftgear downward from the centered position, the push rod 6 is brought along in a motion containing an axial and a rotary component. The push rod moves rectilinearly in the backward direction under simultaneous turning around a lying axis X in the joint connection 20 between the push rod and the link arm 18 (perpendicular to the plane of the drawing). In the movement of the push rod, the link arm and the torsion bar are brought along in a turning around the standing centre axis Y¹ of the torsion bar. In this turning, the horizontal angle between the push rod and the link arm is changed by a mutual turning around a standing axis of turning Y² included in the joint connection 20. In order to allow the composed motion, the joint connection 20 suitably comprises a ball-and-socket joint or another form of biaxial or universal joint.

Fig. 5 shows an alternative embodiment wherein the link arms 18 of the push rods cross each other under the bearing bracket and are connected with the torsion bar situated on the opposite side of the bearing bracket. The embodiment is particularly suitable in an application wherein a greater length is desired of the link arm without the width of the installation needing to be increased.

In the embodiment according to Fig. 6, the torsion bars 8 and 9 are oriented upright and turnably mounted in the attachments thereof on the bearing bracket, or where appropriate to the vehicle chassis, but mutually non-turnably connected by a stay 21, which extends between a respective arm 22, 23 that is non-turnably coupled to the upper end of the appurtenant torsion bar.

In the lack of a stop for the movement of the arms 22, 23, the embodiment can be utilized to allow, within a limited range of angles, unhindered lateral swinging of the draftgear in the unaltered or neutral vertical position, with synchronized co-rotation of the torsion bars, and without any one of these being loaded beyond the level required to hold the draftgear in its neutral vertical position. The embodiment simultaneously entails that a restoring force is available at once to both push rods if the draftgear would move downward from its neutral vertical position.

In combination with a deflection limiter 24 (see Figs. 3 and 4) or 29 (see Fig. 7) for the possible swinging of the link arms toward the position of the push rods in the neutral position of the draftgear, the stay 21 may advantageously be arranged with an adjustable length for the setting of a bias force that the torsion bars apply to the link arms toward the deflection limiter. The stay 21 may advantageously be made as a turnbuckle.

In the swinging of the draftgear laterally, in this case, the stay 21 apportions the load to both torsion bars, which spares the directly loaded torsion bar on the side toward which the draftgear swings. Since the deflection limiter in this embodiment entails that the push rod of the opposite side essentially is unloaded and remains essentially inactive, at least as long as the draftgear keeps its neutral vertical position, the one-sided force implies that the draftgear immediately is restored to its centered position.

It will be appreciated that the length of the link arm 18 between the torsion bar and the push rod implies a corresponding reduction of the turning of the torsion bar upon a given push rod motion. It will likewise be appreciated that the link arm acts as a lever and that its length should be adapted to the torsional stiffness of the torsion bar, which foremost is determined by the material composition and the dimensions of the torsion bar. Therefore, no general recommendations in these respects can be given but have to be calculated by a person skilled in the art for each particular load case. Suitably, however, a spring steel is selected for the manufacture of the torsion bar, which may be made in the form of a leaf spring package or in the form of a homogeneous round bar. Fig. 7 shows an alternative and preferred embodiment that provides an utmost space-saving and compact installation. In this embodiment, the torsion bars 8 and 9 run through the swivel joint 4, and more precisely in drillings recessed therefor on opposite sides of the centre C of the shaft included in the swivel joint. Fig. 7 shows the underside of the draftgear in an embodiment wherein the connection between torsion bar 8 and push rod 6 is formed to provide an

adaptation of the motion and load of the push rod to the strength and elasticity of the selected torsion bar. The embodiment according to Fig. 7 comprises a link arm 25 that acts as a lever and, in one of its ends, is pivotally connected with the rear end of the push rod by the joint connection 20 in the way described above. The other end of the link arm is turnably mounted on the underside of the bearing bracket 5, and suitably on the swivel joint 4 of the draftgear. In other words, the link arm 25 is journalled on top of the link arm 25 of the opposite side, wherein the two link arms 25 can be mutually freely movable in relation to each other. The link arm 25 is acted upon by a rocker arm 26 non-turnably coupled to the torsion bar 8. More precisely, the link arm is actuated via a freely rotating roller 27 that is journalled in the same and presses against a rolling path 28 formed on the rocker arm 26. Said rolling path may be straight, angled or curved for a more or less progressive alteration of the torsion resistance of the torsion bar depending on the angle position of the link arm and the position of the roller on the rolling path 28.

In the embodiment according to Fig. 7, the reference numeral 29 designates a stop lug carried on the bearing bracket 5 and having a set screw 30. The set screw 30 co-operates with a lug 31 formed on the link arm 25 in order to, in this way, form an adjustable deflection limiter for the link arm 25, by which the bias of the torsion bar is adjustable. Fig. 8 shows a modified embodiment of the coupler centering device according to Fig. 7. The embodiment according to Fig. 8 is different in respect of the placement of the torsion bars 8, 9, which in this case are journalled on the outside of the bearing bracket 5. A rocker arm 26' non-turnably arranged in the end of the torsion bar acts upon the link arm 25' via a roller 27' that is rotatably mounted in the link arm 25' and rests against a rolling path 28' formed on the rocker arm. The modified embodiment according to Fig. 8 provides increased possibility of adapting the function to a progressive mode of operation.

Fig. 9 shows an embodiment wherein the torsion bars 8, 9 of the coupler centering device run through the shaft of the swivel joint 4. Like the embodiment according to Fig. 6, in their upper ends, the torsion bars 8 and 9 are mutually non-turnably connected by the arms 22, 23 and the interconnected stay 21 , which here is made as a set screw 21. By extension or shortening of the stay 21, the torsion bars 8, 9 are turned in opposite directions, whereby their bias against a stop lug 29 can be regulated.

In a particularly compact and light design, the link arms 25 may be directly and non-turnably coupled to the lower ends of the torsion bars, and assigned a stop lug 29 formed on a centering device attachment 32 carried in the shaft of the swivel joint 4. In this way, a coupler centering device is provided in a preferred way in the form of an assembly, schematically illustrated in Fig. 10, that is easily mountable in the bearing bracket.

The embodiments of the coupler centering device accounted for above all affords possibility of a compact and space-saving installation of the bearing bracket, or alternatively and where appropriate on the chassis of the vehicle.

Claims

1. Centering device for a draftgear pivoted to a vehicle chassis, particularly in an automatic coupler for a rail vehicle, which centering device is effective to hold the draftgear in a centered position for coupling, comprising a first and a second push rod (6, 7), which run separated side by side under the draftgear, and which push rods, by their front ends, support the draftgear from below, the push rods (6, 7) being coupled to a respective torsion bar (8, 9) that is effective to elastically hold the appurtenant push rod in a supporting position, characterized in that the torsion bars (8, 9) extend in an upright orientation.

2. Centering device according to claim 1 , characterized in that the torsion bars (8, 9) in their upper ends are non-turnably coupled to a respective arm (22, 23), and mutually connected by a stay (21) coupled between the arms.

3. Centering device according to claim 2, characterized in that the torsion bars (8, 9) are mutually connected by an interconnected stay (21) of an adjustable length.

4. Centering device according to any one of claims 1-3, characterized in that the torsion bars (8, 9) are arranged to hold the push rods (6, 7) in a supporting position under bias.

5. Centering device according to any one of claims 1-4, characterized in that each push rod is assigned a respective torsion bar (8, 9) that acts upon the push rod in question via a link arm ( 15, 18, 25) connected with the push rod.

6. Centering device according to claim 5, characterized in that the link arm (18, 25) is assigned a deflection limiter (24, 29) that determines an end position of the movement of the link arm.

7. Centering device according to claim 6, characterized in that the deflection limiter (29) is adjustable for changing the end position of the link arm.

8. Centering device according to any one of claims 5-7, characterized in that the link arm (25) is a lever that is hinged in a fulcrum and acted upon by a rocker arm

(26) non-turnably coupled to the torsion bar (8, 9).

9. Centering device according to claim 8, characterized in that the link arm (25) comprises a freely rotating roller (27) pressing against a rolling path (28) formed on the rocker arm (26) of the torsion bar.

10. Centering device according to claim 9, characterized in that the rolling path (28) is straight, angled or curved.

1 1. Centering device according to any one of the above claims, characterized in that the torsion bars (8, 9) extend on both sides of a swivel joint (4) mounted in a bearing bracket (5).

12. Centering device according to claim 1 1, characterized in that the torsion bars (8, 9) extend in parallel through the swivel joint (4) on opposite sides of the centre (C) of the shaft included in the swivel joint (4).

13. Centering device according to any one of claims 5-12, wherein the torsion bars (8, 9) extend upright on both sides of the swivel joint (4) of the draftgear,

characterized in that the link arms ( 18) cross each other and are acted upon by the respective torsion bar (8, 9) that is situated on the opposite side of the swivel joint (4) of the draftgear.