EP4069571B1 - Screw coupling for coupling two rail vehicles - Google Patents

Description

The present invention relates to a screw coupling for coupling two rail vehicles, wherein the rail vehicles have draw hooks or other coupling devices into which the screw coupling with its coupling elements can be hooked or inserted in order to couple the two coupling devices to one another. The invention further relates to an unscrewing protection device for such a screw coupling.

Screw couplings are used to couple two rail vehicles together, for example with their draw hooks. For this purpose, the screw couplings each have two coupling elements at their two axial ends. Between the coupling elements there is a threaded rod, also called a spindle, onto which the coupling elements are screwed. This means that the distance between the two coupling elements can be changed by turning the threaded rod and the screw coupling can be tightened between two rail vehicles that are supported on each other, for example via buffers.

The coupling elements of the screw couplings usually each have an eyelet that can be pushed over the corresponding draw hook and hooked into it. In principle, however, the present invention can also be used with differently designed screw couplings, for example with transition couplings or mixed train couplings, in which the coupling elements can be designed differently from one another, either in that the eyes have different axial lengths or in that instead of an eyelet another coupling element is provided for connection to a coupling device on a rail vehicle. The present invention can also be used with screw couplings in which both coupling elements do not have an eyelet, but have differently designed coupling elements.

In order to prevent the threaded rods from being completely unscrewed from the coupling elements, screw couplings of this type have an anti-screwing device at each axial end of the threaded rod onto which a coupling element is screwed. A disc welded to the threaded rod and projecting radially beyond the threaded rod is often provided as an anti-screwing device, so that this disc blocks the coupling element from being unscrewed beyond the axial end of the threaded rod. Such a design is available, for example, from GB1911/11136A Other known anti-screwing devices have a split pin or dowel pin at the axial end of the threaded rod, which protrudes radially beyond the external thread of the threaded rod and thus blocks the coupling element from being unscrewed beyond the axial end of the threaded rod. Another version with a screw lock arranged at the end of the threaded rod is in FR 26381 E described.

Furthermore, key ring locks are known as unscrewing locks at the axial end of the threaded rod. In this case, a spring-loaded wire ring with a slot around its circumference is inserted behind a shim and a ring into a groove at the axial end of the threaded rod so that it protrudes radially outwards from the groove and thus blocks the screwed-on coupling element from being unscrewed beyond the axial end of the threaded rod.

The known anti-screwing devices each have disadvantages. In the solution with a disc welded to the front end of the threaded rod, heat is introduced into the threaded rod when the disc is welded on. The threaded rod is usually made of high-strength tempering steel. This heat can lead to unfavorable structural changes in the material of the threaded rod and the welding process requires extensive preparation and a specially trained welder, who is usually only available in selected workshops.

With solutions using a split pin, roll pin or spring ring, there is a risk that the anti-screwing device will accidentally come loose from its holder. For example, a roll pin can be knocked out of the corresponding through hole in the threaded rod and a moment acting on the spring ring pushes it out of the groove. In both cases, the anti-screwing device no longer functions and the threaded rod can accidentally be unscrewed from the coupling element, which can damage the threaded rod and injure operating personnel. There is also a risk that the threaded rod has not yet been completely unscrewed from the coupling element, but is screwed into the coupling element with an insufficient number of turns, meaning that the threaded rod is torn out of the coupling element when the rail vehicles are moving and the vehicles are separated from one another.

The publication GB 2 014 265 A discloses a manipulation protection device for preventing only an unauthorized angle adjustment of an adjustment element for a fuel injection pump device, which adjustment element forms a stop and is designed as a threaded rod. This comprises a one-piece elastic ring element that is not closed in the circumferential direction, which is placed in a groove at the end of the threaded rod and is fixed on the outer circumference via a cap element. The cap element only prevents unauthorized access to the threaded rod and thus an adjustment that occurs as a result, but can rotate relative to it in the circumferential direction.

EP 2553 277 A1 generally discloses a retaining ring for a captive connection. The retaining ring comprises an outer ring having an outer surface and an inner surface and at least one spring beam element extending from the inner surface of the outer ring; and a centrally located opening dimensioned and shaped to receive a bolt, wherein upon engagement of the bolt in the retaining ring, the at least one spring beam element is displaced and extends radially from from a free position to an extended position so that the bolt can pass through the opening. This type of locking requires a high level of manufacturing effort for the individual elements.

The present invention is based on the object of specifying a screw coupling for coupling two rail vehicles, which has a simple structure and at the same time avoids the disadvantages mentioned above. Furthermore, an unscrewing protection device for such a screw coupling is to be specified. The unscrewing protection device should have a simple structure and require as little installation space as possible in order to be able to be integrated into existing screw couplings as a retrofit solution.

The object according to the invention is achieved by a screw coupling with the features of claim 1. Advantageous and particularly expedient embodiments of the invention are specified in the dependent claims.

A screw coupling according to the invention for coupling two rail vehicles has a threaded rod which carries a coupling element in the region of its two axial ends. The threaded rod is preferably designed as a single piece, but in principle a multi-piece threaded rod can also be used, the individual sections of which are connected to one another via an intermediate piece into which the threaded rod sections are screwed with the ends facing one another.

At least one of the two coupling elements at the two axial ends of the threaded rod is screwed onto an external thread of the threaded rod. Preferably, both coupling elements are screwed onto one axial end of the threaded rod.

The threaded rod can be rotated to vary the distance between the two coupling elements, because by rotating the threaded rod, this is either screwed further into the coupling element(s) or is unscrewed from the coupling element(s). The ability to rotate the threaded rod also includes rotating the coupling element(s) and holding the threaded rod.

At least one axial end of the threaded rod, in particular each axial end of the threaded rod onto which a coupling element is screwed, has an unscrewing device, wherein the unscrewing device blocks the coupling element against unscrewing beyond the axial end of the threaded rod.

According to the invention, the unscrewing device comprises a groove extending over at least part of the circumference, in particular over the entire circumference, of the threaded rod, into which a locking ring protruding radially from the groove is inserted, wherein the locking ring is interrupted over its circumference at least at one point so that it can be inserted into the groove in a form-fitting manner.

According to the invention, a retaining ring which is closed over its circumference and completely encloses the retaining ring is arranged radially on the outside of the retaining ring.

The retaining ring prevents the locking ring from expanding in the radial direction after it has been inserted into the groove at the axial end of the threaded rod. The locking ring can therefore no longer slide out of the groove. At the same time, welding the locking ring to the threaded rod is not necessary, so that a corresponding heat input into the threaded rod is avoided. In particular, the locking ring is inserted into the groove freely, i.e. without a material bond to the threaded rod. In principle, however, the locking ring could be attached to the groove by other material bonding measures, for example by gluing. threaded rod. If a large amount of heat can be avoided, even simple welding or tacking can be considered to make installation easier.

An unscrewing protection device according to the invention for such a screw coupling accordingly has a locking ring which is interrupted at least at one point over its circumference and a retaining ring which can be positioned or arranged radially on the outside of the locking ring and is closed over its circumference and which, when arranged on the locking ring, completely encloses it.

The retaining ring can be connected to the locking ring in a material-locking manner and is in particular welded to it. Additionally or alternatively, the retaining ring can also be shrink-fitted onto the locking ring. Other form-fitting or material-locking fastenings are possible.

The retaining ring is preferably free of a material connection to the threaded rod.

The retaining ring is in particular a ring-shaped element, i.e. an element with at least one outer surface running around an axis in the circumferential direction and pointing in the radial direction. This is formed by a surface of any contour running around this axis with a constant radius. The retaining ring is preferably characterized by a width, i.e. extension in the axial direction, which essentially corresponds to that of the locking ring or is slightly larger in the sense of protruding. The unscrewing protection consisting of the retaining ring and locking ring is therefore relatively compact in the radial and axial directions and does not require any additional installation space. This means that it can also be easily retrofitted in existing systems or replace the known solutions.

According to a particularly advantageous embodiment of the invention, the locking ring comprises several separate ring segments. In particular, the locking ring is composed of two separate ring segments, whereby these ring segments can form half-shell elements which can then be inserted into the groove in the threaded rod in a form-fitting manner, together completely or almost completely enclose the threaded rod around the circumference and are held in the groove by sliding the closed retaining ring over it. The at least two-part design is easy to assemble and the individual ring segments remain relatively dimensionally stable even under the influence of torsion.

According to an alternative embodiment, the locking ring is interrupted exactly once around its circumference. It can thus be pushed over the threaded rod into the groove in the manner of a spring ring, particularly transversely to the longitudinal axis of the threaded rod, and is preferably expanded elastically. Once it has been inserted into the groove, particularly snapped into it, the retaining ring can be pushed radially outward onto the locking ring and prevent it from expanding again.

According to a particularly advantageous embodiment of the invention, the unscrewing device comprises an axial disk which is arranged axially next to the locking ring on the threaded rod and forms an axial contact surface for the locking ring and the retaining ring. Accordingly, the axial disk projects beyond the locking ring in the radial direction, so that the retaining ring arranged on the locking ring can be supported on the axial disk in the axial direction.

According to one embodiment, the axial disk can be positioned in the groove together with the locking ring. Preferably, however, the axial disk is arranged outside the groove on the threaded rod and in particular in the axial direction against a collar of the threaded rod at the axial end of the external thread of the threaded rod.

The coupling element(s) can in particular be screwed directly onto the threaded rod and preferably each have a screw body provided with an internal thread, which is screwed onto the external thread of the threaded rod, as well as a coupling eyelet connected in an articulated manner to the screw body.

In order to be able to rotate the threaded rod and to apply the drive torque with a lever, a lever is preferably connected to the threaded rod in a rotationally fixed manner in an axially central area of the threaded rod. Such a lever can have a base body that is connected to the threaded rod in a rotationally fixed manner and a handle that is connected to it in an articulated manner.

The groove in the threaded rod into which the locking ring is inserted preferably has a rectangular cross-section. However, other cross-sectional shapes are also possible, for example a V-shaped cross-section.

The locking ring preferably has a shoulder that rests axially next to the groove on a radially outer surface of the threaded rod when the locking ring is inserted into the groove. For example, the locking ring has a T-shaped cross-section, wherein a foot region of the T-shaped cross-section engages in the groove and a roof region of the T-shaped cross-section extends in the axial direction on the outside of the threaded rod and thus preferably forms two radially inner shoulders that rest radially on the outside of the threaded rod.

If only one shoulder is to be provided, the retaining ring has, for example, an angle shape, with one leg of the angle engaging in the groove and the other leg of the angle forms the shoulder. The cross-sectional shapes refer to an axial section through the retaining ring, i.e. through the section along the longitudinal direction of the threaded rod, each related to a side next to the longitudinal axis.

The unscrewing lock preferably has such a maximum radial extension that it can be moved within a bore of the respective coupling element.

The invention will be described below using an embodiment and the figures as examples.

Figur 1

eine dreidimensionale Ansicht einer erfindungsgemäßen Schraubenkupplung;

Figur 2

eine axiale Draufsicht auf eine erfindungsgemäße Abschraubsicherung;

Figur 3

einen Axialschnitt entlang der Schnittlinie A-A aus der Figur 2 durch die Abschraubsicherung mit angrenzenden Bereichen der Schraubenkupplung.

Show it:

Figure 1

a three-dimensional view of a screw coupling according to the invention;

Figure 2

an axial plan view of an unscrewing device according to the invention;

Figure 3

an axial section along the section line AA from the Figure 2 through the unscrewing protection with adjacent areas of the screw coupling.

In the Figure 1 a screw coupling according to the invention is shown, with which two rail vehicles, each comprising a draw hook, can be coupled to one another. The screw coupling has a threaded rod 1, which is also referred to as a spindle, to whose two axial ends a coupling element 2, 3 is screwed. The coupling elements 2, 3 can also be attached to a coupling device of the rail vehicle other than a draw hook, for example to a bolt 20, as shown schematically here by shown in dashed lines. The coupling elements 2, 3 are designed here in particular as screw coupling brackets.

Each coupling element 2, 3 has a screw body 15, here in the form of a cube or cuboid, which comprises an internal thread 14 that is screwed onto the external thread 4 of the threaded rod 1. A coupling eyelet 16 is connected in an articulated manner to the screw body 15, which can be pushed or hooked over a corresponding component on the rail vehicle, for example a towing hook or bolt 20, in order to establish a positive connection, at least for tensile forces, with the rail vehicle.

In order to be able to rotate the threaded rod 1 more easily and thereby change the distance between the two screw bodies 15, a lever 17 is connected to the threaded rod 1 in a rotationally fixed manner in the axial center of the threaded rod 1 between two sections of the external thread 4. This can be gripped and forms a lever for introducing the torque into the threaded rod 1.

When the threaded rod 1 is rotated about its longitudinal axis 19 in a first direction, the two screw bodies 15 are moved towards each other. When rotated in an opposite second direction, the screw bodies 15 are moved apart. In the latter case, there is a risk that the screw bodies 15 will be unscrewed from the threaded rod 1, which is why an unscrewing lock 5 is provided in the area of each axial end of the threaded rod 1.

The unscrewing lock 5 preferably has such a maximum radial extension that it can be displaced within a bore of the screw body 15.

Details of an advantageous unscrewing protection are in the Figures 2 and 3 shown.

Each unscrewing lock 5 has a locking ring 7 which concentrically encloses the longitudinal axis 19 of the threaded rod 1 and is inserted into a groove 6 in the area of the axial end of the threaded rod 1. The locking ring 7 has at least one interruption over its circumference. In the embodiment shown, the locking ring 7 is composed of two separate ring segments 7.1, 7.2 which, when inserted into the groove 6, are only slightly spaced apart from one another in the circumferential direction, so that they enclose the threaded rod 1 almost over its entire circumference.

The ring segments 7.1 and 7.2 each have a T-shaped cross-section when viewed in an axial section through the longitudinal axis 19, with the foot area being inserted into the groove 6 and the roof area forming two radially inner shoulders 18 that rest on the outer circumference of the threaded rod 1. This allows the ring segments 7.1 and 7.2 to be easily and precisely positioned and held on the outside of the threaded rod 1 or in the groove 6.

In order to prevent the ring segments 7.1 and 7.2 from coming loose from the groove 6, a retaining ring 8 is pushed radially outward onto the locking ring 7, i.e. onto both ring segments 7.1 and 7.2, which is closed over its circumference and completely encloses the locking ring 7. The retaining ring 8 is preferably welded to the locking ring 7, for example with several weld seams 13 distributed over the circumference.

In order to facilitate welding, the retaining ring 8 preferably has a chamfer 12 on its front end facing away from the external thread 4, into which the weld seams 13 can be introduced, so that the weld seams 13 cover the radially obliquely inwardly directed surface of the chamfer 12 and the radially outward-facing surface of the retaining ring 7 exposed by the chamfer 12.

The radially outer surface 21 of the retaining ring 8 can be designed as a free surface, in particular as a cylindrical surface, and can have a distance from the surrounding components of the screw coupling.

Preferably, an axial disk 9 is provided axially next to the locking ring 7 and the retaining ring 8 radially on the outside of the threaded rod 1, which forms an axial contact surface 10 for both the locking ring 7 and the retaining ring 8. The axial disk 9 is preferably supported on a collar 11 at the end of the external thread 4 against the threaded rod 1.

The axial disk 9 ensures that the locking ring 7 and the retaining ring 8 are aligned with each other in the radial direction and can also represent a stop surface for the screw body 15 in order to block it against unscrewing beyond the axial end of the threaded rod 1.

Reference symbols

1

Threaded rod

2

Dome element

3

Dome element

4

External thread

5

Unscrewing protection

6

Groove

7

Retaining ring

7.1, 7.2

Ring segment

8th

Retaining ring

9

Axial disc

10

Axial contact surface

11

Federation

12

chamfer

13

Weld

14

inner thread

15

Screw body

16

Coupling eyelet

17

scissors

18

shoulder

19

Longitudinal axis

20

bolt

21

radial outer surface

Claims (13)

1. Screw coupling for coupling two rail vehicles,

   having a threaded rod (1) which bears in the region of its two axial ends in each case one coupling element (2, 3), wherein at least one of the coupling elements (2, 3) or both coupling elements (2, 3) is/are screwed onto an external thread (4) of the threaded rod (1) and the threaded rod (1) is rotatable in order, in this way, for the distance between the two coupling elements (2, 3) to be varied;

   having at least one unscrewing-prevention means (5) on the axial end of the threaded rod (1) onto which the coupling element (2, 3) is screwed, wherein the coupling element (2, 3) is blocked against unscrewing beyond the axial end of the threaded rod (1) by the unscrewing-prevention means (5); and

   the unscrewing-prevention means (5) comprises a groove (6) which extends at least over a part of the periphery of the threaded rod (1) and into which is inserted a securing ring (7) radially projecting from the groove (6), wherein the securing ring (7) is interrupted over its periphery at least at one point;

   characterized in that

   a retaining ring (8) which is closed over its periphery is arranged on the radially outer side of the securing ring (7) and surrounds the securing ring (7) over its entire periphery.
2. Screw coupling according to Claim 1, characterized in that the securing ring (7) is made up of at least two ring segments (7.1, 7.2) which are separated from one another.
3. Screw coupling according to Claim 1, characterized in that the securing ring (7) is interrupted over its periphery exactly once.
4. Screw coupling according to one of Claims 1 to 3, characterized in that the retaining ring (8) is connected in a materially bonded manner, in particular is welded, to the securing ring (7).
5. Screw coupling according to one of Claims 1 to 4, characterized in that the retaining ring (8) is shrink-fitted onto the securing ring (7).
6. Screw coupling according to one of Claims 1 to 5, characterized in that the securing ring (7) is free of a materially bonded connection to the threaded rod (1).
7. Screw coupling according to one of Claims 1 to 6, characterized in that the unscrewing-prevention means (5) furthermore comprises an axial disc (9) which is arranged on the threaded rod (1) so as to be axially adjacent to the securing ring (7) and which forms an axial abutment surface (10) for the securing ring (7) and for the retaining ring (8).
8. Screw coupling according to Claim 7, characterized in that the axial disc (9) is arranged on the threaded rod (1) outside the groove (6), and is supported in particular in the axial direction against a collar (11) of the threaded rod (1) at the axial end of the external thread (4).
9. Screw coupling according to one of Claims 1 to 8, characterized in that the securing ring (7) has at least one shoulder (18) which bears on a radially outer surface of the threaded rod (1) so as to be axially adjacent to the groove (6).
10. Screw coupling according to Claim 9, characterized in that the securing ring (7) has a T-shaped cross section, wherein a base region of the T-shaped cross section engages into the groove (6) and a top region of the T-shaped cross section extends in the axial direction on the outer side of the threaded rod (1).
11. Screw coupling according to one of Claims 1 to 10, characterized in that, at at least one axial end, the retaining ring (8) has on its radially inner side, which faces the securing ring (7), a bevel (12) which frees a radially outer surface region of the securing ring (7), and at least one weld seam (13) is introduced into the bevel (12).
12. Screw coupling according to one of Claims 1 to 11, characterized in that the screwed-on coupling element(s) (2, 3) comprises/each comprise a screw-connection body (15) which is provided with an internal thread (14) and which is screwed onto the external thread (4) of the threaded rod (1), and a coupling eyelet (16) which is connected in an articulated manner to the screw-connection body (15) .
13. Screw coupling according to one of Claims 1 to 12, characterized in that a handle (17) is connected in a rotationally conjoint manner to the threaded rod (1) in an axially central region of the threaded rod (1) .

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