GB2056389A - Buffer stop, especially as a train leading end safety means in a shunting station - Google Patents

Abstract

The buffer stop, comprises two halves (only one shown) each pivotally articulated at (4) to an abutment arranged outside the drive tracks (7) and each comprising a buffer member carrying a buffer (3). A power member e.g. servo motor (5) acts between the track foundations (6) and the associated buffer stop half, to move the latter between its operative (full- line) and inoperative (dashed line) positions. To facilitate withdrawal of the buffer stop halves when they are loaded by the weight of a wagon, the buffers (3) have a low-friction contact surface e.g. by reason of balls 11. <IMAGE>

Description

SPECIFICATION Buffer stop, especially as a train leading end safety means in a shunting station The invention relates to a buffer stop serving especially as a train leading end safety means in a shunting station, comprising two buffer stop halves subdivided longitudinally of the rails and pivotally articulated to an abutment arranged outside the drive track, while being respectively provided each with a buffer, and a respective power member provided between a bearing portion of the abutment and the associated buffer stop half.

So-called hinge-down buffer stops for temporarily blocking passage rails are known; they are employed temporarily to render continuous rails into terminal rails in connection with waggon washing operations, for example, and at filling stations etc., but also in connection with railway ferries (German patent letter 884 956).

In the case of the known buffer stop the abutments of the buffer stop halves are provided with frictional members which are arranged to be longitudinally displaceable under frictional engagement on carriers provided to extend in parallel with the drive tracks, using up the kinetic energy through frictional effort.

With the known buffer stop it does not cause any particular difficulties to hinge it down outwards from the basic position, in order to release the rail. Under normal circumstances at least two operators are needed for this operation.

To obtain one-man operation, it has also become known already to connect a spring arrangement to a bearing portion of the abutment by the one end thereof and to a buffer stop half by the other end thereof in such a manner that with the buffer stop half pivoted from its position of readiness the spring arrangement will be tensioned and will attempt to urge the buffer stop half back (German publication letter 2 710 965). The spring arrangement stores a considerable portion of the kinetic energy created with the pivotal movement of the buffer stop half from the position of readiness into the pivoted position, which then with the buffer stop half being pivoted back into the position of readiness will be used to assist human power.

On many shunting stations there are provided so-called run-down hills from which the individual waggons run down and where they are distributed into the corresponding directional rails. At a predetermined point the individual waggons which are running down must then come to a standstill. To control the speed costly rail brakes are utilized along the path they are running down.

Such shunting operations have repeatedly caused difficulties and accidents in the past. The work of the shunting personnel, in particular, who are working with drag shoes, is dangerous, costly and inaccurate.

If stationary buffer stops are employed in such shunting operations which, by the way, are taking place also on shunting stations having no slope, the locomotive must perform a considerable shunting trip to drive a train that has been placed in readiness into the corresponding directional rail.

The invention is based upon the problem of providing a buffer stop that may be employed as a train leading end safety means in a shunting station, reducing the dangers to shunting personnel prevailing with conventional shunting operations, and making possible radical saving in shunting personnel.

According to the invention this problem is solved in that the power member is an adjustment servo motor actuable by a control means, and the buffer surface of the buffers is designed to be poor in friction.

With the invention a buffer stop capable of being hinged down has been proposed for the first time for use as a train leading end safety means in a shunting station. A conventional buffer stop capable of being hinged down, when used for this purpose, however, would not yet be capable of function, because the waggon buffers would press against the buffers of the buffer stop halves. With a train standing on a sloped path, the entire load of the individual waggons of up to 2,000 tons comes to bear on the buffer stop members.

Therefore, provision is made in the invention for a servo motor with the aid of which the buffer stop halves may be adjusted with the necessary amount of power so that the waggon buffers engaged with the buffer stops may be separated.

As, now, the frictional engagement between the buffer members of the buffer stop and the waggon buffers may be extremely high, the invention eventually provides for a design of the buffer surfaces of the buffer stop members to be poor in friction. Thereby it is possible for the buffer stop halves to be moved relatively quickly from the basic position into the hinged-down position.

Such a function is particularly necessary when the train that has been made safe is standing on a slope. Upon release of the rail by the buffer stops being hinged down the waggons will follow very quickly so that it must be secured that the following waggons will not interfere with the buffer stop.

The locomotive may wait in rear of the buffer stop and may move immediately into the respectively desired direction together with the pre-arranged train without any costly and timeconsuming shunting trips becoming necessary.

The control of the servo motors for the buffer stop capable of being hinged down may be located at a place remote from the buffer stop, for example, in a protective booth. By the arrangement of the control for several buffer stops according to the invention in one and the same place it is intended to save on the costly employment of personnel was well as to protect the personnel from danger, especially when working at night and in winter.

There are various possibilities of designing the buffer surface of the buffer stop capable of being hinged down in a manner to be poor in friction. In one embodiment of the invention provision is made for this purpose for roller members, especially balls, to be mounted in the buffer surface. Between the buffer members of the buffer stop and the waggon buffers there will thus form a rolling friction upon a pivotal movement performed by the buffer stop. Owing thereto, the servo motor may be dimensioned to be relatively small while being yet able to guarantee a quick adjustment of the associated buffer stop half under load. The roller members are preferably resiliently supported, either as an overall arrangement or singly, with each roller member needing a spring in the latter case.

To drive the buffer stop any usual hydraulic, pneumatic or electric servo motor may be employed. For this purpose provision is made in another embodiment of the invention for the servo motor to be a linear motor, especially a pressure medium actuated servo cylinder. With pressure medium actuated servo cylinders, for example, hydraulic servo cylinders, the hydraulic pump is preferably built in in a nearby situated protective booth together with the control means. Control is effected preferably via electromagnetic valves.

The hydraulic pump which is preferably driven by an electric motor may be used to supply the hydraulic drives at several buffer stops designed in accordance with the invention.

As has already been mentioned above, it is desirable that the hinging-down of the buffer stop halves be performed as quickly as possible so that the following waggon will not strike against parts of the halfway hinged-down buffer stop. Another embodiment of the invention provides in this connection for the servo cylinder to be in the form of a tandem cylinder and for the control means to be designed in such a manner that with the associated buffer stop pivoted out of the vicinity of the rail the piston having the larger effective area is biased first with the pressure medium, and subsequently the piston having the smaller effective area. As, usually, a constant displacement pump is employed, a pivotal movement of the buffer stop from the position of readiness will at first take place relatively slowly, namely, until the buffer stop halves have got clear of the waggon buffers.Then, the piston having the smaller effective area will come into action which will correspondingly perform a quicker hingedown movement. It goes without saying that in addition to the pumping aggregate a hand pump may be employed for the pressure medium, in order to make possible manual operation of the buffer stop in case of emergency.

To avoid damages and disturbances in operation provision is made in another embodiment of the invention for the servo motor to be disposed beneath the pivot bearing in a countersunk arrangement. The cavity occupied by the servo motor may in addition be closed by a covering, so that the motor is eliminated from the rough operation.

It may indeed be imagined, as is known per se, to arrange the buffer stop halves to be capable of longitudinal displacement under frictional engagement on carriers provided to extend in parallel with the drive tracks. Within the framework of a shunting operation, however, the retraction movement of the displaced buffer stop will have to be provided for.

In an embodiment of the invention provision is made instead for the pivot bearings and the servo motors to be supported on a concrete foundation.

The concrete foundation is preferably made in one piece and supports also the drive tracks.

In another embodiment of the invention the concrete foundation is respectively provided with an open top cavity on the outside of the associated buffer stop half in order to accommodate the servo motor. The cavities are preferably closed by suitable coverings.

Besides, a concrete foundation offers the advantage that control and pressure lines, respectively, within the vicinity of the buffer stop may be safely guided to the servo motor.

Otherwise the danger exists that hydraulic lines, for example, might be damaged in the rough operation of a shunting station.

With a stationary buffer stop, said buffer stop and the oncoming waggons are constantly subjected to concussions. Therefore, provision is made in another embodiment of the invention for the buffers to be fitted at the plunger of a hydraulic cylinder. The plunger is preferably provided with an automatic retraction means to return it to the basic position. A hydraulic buffer arrangement is basically known (German disclosure letter 2 755 565). It is employed in connection with an advance unit which is movably connected to the rails. With the known device, in case of minor run-up movements, the hydraulic buffer arrangement will yield and use up part of or the entire run-up energy. With the present invention, as already mentioned, the hydraulic buffer arrangement without the advance unit essentially serves to reduce concussions and to brake minor run-up energies.For an actual braking effect in the sense of a braking buffer stop a hydraulic buffer arrangement is not suited because, with quicker run-up movements it will have the effect of a stationary buffer stop.

In the following, one example of embodiment of the invention will be explained in more detail by way of drawings, in which: Fig. 1 is a side view of a buffer stop designed in accordance with the invention; Fig. 2 is a top plan view of one half of a buffer stop designed according to Fig. 1; Fig. 3 is a sectional front view of the buffer stop half according to Fig. 2 with the sectional line passing through the foundation; Fig. 4 is a sectional view taken on line 4-4 through the buffer stop half as shown in Fig. 3.

Prior to dealing in more detail with the representations shown in the drawings, it is to be stated that each one of the features as shown and described is essential to the invention either by itself or in combination with features of the claims.

In the drawings, 1 designates an impact triangle of a buffer stop, which is pivotally supported with the aid of hinges 4 on the outer surface of a drive track 7. As will be seen from Fig. 3, the drive track 7 and hinges 4 are supported on a concrete foundation 6 via a formation of plastics mortar 10, said foundation extending essentially the length of the impact triangle 1 (see Fig. 1 ) and on either outer surface of the drive track 7 (see Fig. 2 and 3, respectively).

Connected to the upper surface of the impact triangle 1 is a buffer arrangement 2 which consists of a cylinder arrangement and a plunger arrangement. The cylinder arrangement which is composed of two stepped sections is welded to the triangle 1. The hydraulic buffer arrangement 2 is known as regards the construction thereof and, therefore, will not be described in any more detail.

The cylinder arrangement is filled with hydraulic oil, while the plunger arrangement is filled with nitrogen. With the plunger arrangement biased, the hydraulic oil will be forced through a controllable passage opening into the nitrogen chamber. The nitrogen will be compressed in this manner and will act as a return spring for the plunger arrangement.

Connected to the free end of the plunger arrangement is a buffer 3. The impact surface of the buffer 3 on a circular circumference 6 mounts balls 11 which are supported with the aid of springs and which project but by a minor amount above the impact surface.

The impact triangle 1 is provided on the outer surface thereof with a bifurcated bracket 1 2 which forms a pivot bearing for the piston rod 1 3 of a hydraulic servo cylinder 5. The cylinder for its part is pivotally supported in a bifurcated bracket 9.

The bracket 9 is disposed within a cavity 14 in the concrete foundation 6, i.e. at the bottom of the cavity 14. The cavity 14 is closed by a removable cover plate 1 5 capable of being walked on, except for an opening 1 6 through which the piston rod 13 extends. A bevelling 1 7 of the facing edge of the concrete foundation makes possible a favourable arrangement and fitting of the servo cylinder 5 from an energy point of view. With this it is possible to move the impact triangle 1 from the position shown in full lines into the position shown in dashed lines in Fig. 3, and vice versa. In the position shown in dashed lines the impact triangle with the buffer 3 is disposed outside the contour 1 8 of a waggon which is indicated in dash-dotted lines.

The servo cylinder 5 is a so-called tandem cylinder, that means it comprises two seriesarranged pistons having differently dimensioned effective areas.

In the foundation 6 channels 1 9 are formed for the accommodation of hydraulic lines. So, for instance, the hydraulic lines for servo motor 5 and for the servo motor arranged in the same manner for the other buffer stop half may be conducted via the channel 1 9. Channel 20 serves draining purposes.

As will be seen as a whole from Figs. 1 to 3, the foundation 6 beneath the drive tracks adjacent the impact triangles and immediately beneath the impact triangles is formed as a thick and massive plate. Joining the plate on either side of the outer surface of the impact triangles are open top concrete boxes which are formed in one piece with the massive plate. The concrete boxes which form the cavity 1 4 are substantially shorter than the massive plate.

As may be recognized from Fig. 4, the bracket 9 comprises a base plate 21 having two bearing plates 22, 23 welded thereto to extend in parallel normal to the plates and having openings 24 aligned to receive a bearing pin for the purpose of supporting the end of the cylinder arrangement 5 (see Figs. 1 to 3).

The base plate 21 is anchored in the bottom of the box-like portion of the concrete foundation 6 with the aid of dowels 8.

The servo cylinders of the buffer stop arrangement shown are actuated by a hydraulic aggregate which is mounted in a nearby protective booth (not shown). The control of the biasing of the servo cylinders 5 is effected with the aid of electromagnetic valves which for their part are controlled by an electric control arrangement. The electric control for operating the hydraulic valves with the aid of a push-button key is likewise installed in the protective booth. Finally, there is a hand pump built in at the hydraulic aggregate (of a hydraulic pump and an electric motor) which makes it possible to actuate the servo cylinders 5 manually in case of current failure. It goes without saying that a hydraulic aggregate is in a position to supply several servo cylinders of several buffer stops in parallel.

At the buffer stop according to the invention when in the hinged-up condition individual waggons will gradually come to a standstill. The impact forces of the respectively following waggons will be braked by the hydraulic buffer arrangement 2. After the train has been completely arranged, the impact triangles 1 will be hinged down under load so quickly that the following waggons will not strike against the triangles 1. In rear of the buffer stop the locomotive is waiting which may immediately drive into the respectively desired direction with the arranged train.

The servo cylinder 5 is a tandem cylinder and, with the impact triangles 1 being hinged down, the large piston is adjusted first with correspondingly slow movements. Thereby it is safely obtained that with the output capacity available of the servo cylinder the buffer 3 will be capable of relative movement via-a'-vis the buffer of the waggon which is stationary in the plane of pivotal movement. The movement is facilitated by the balls 11 making possible a rolling friction. The piston having the larger effective area in the cylinder arrangement 5 will be fed until the buffer stop halves have got clear of the waggon buffers.

Then the piston having the smaller effective area will be actuated which will correspondingly perform a quicker hinge-down movement. In this manner it is possible to perform the buffer stop movement smoothly and quickly and to enable a waggon to continue its running movement on a slope towards a locomotive without the waggon darting forth damaging the buffer stop.

Although in the foregoing description use with sloping paths has been strongly pushed into the foreground, attention is once more drawn to the fact that the invention may be used to advantage also on even ground shunting stations. A quick hinge-down movement of the impact triangles, however, is not required for such cases so that, for instance, also an electric motor may be used to adjust the impact triangles with constant speed.

Claims (15)

1. A buffer stop, especially as a train leading end safety means, comprising two buffer stop halves subdivided longitudinally of the rail which are pivotally articulated each to an abutment arranged outside the drive tracks and each comprise a buffer member, and a respective power member between the bearing section of the abutment and the associated buffer stop half, the power member being a servo motor actuable by a control device and the buffer surface of the buffers being designed to be poor in friction.

2. The buffer stop according to claim 1, wherein the buffer surface has roller members, especially balls, mounted therein.

3. The buffer stop according to claim 2, wherein the roller members are resiliently supported.

4. The buffer stop according to claim 1 or 2, wherein the roller members are arranged on a circular circumference.

5. The buffer stop according to any one of claims 1 to 4, wherein the servo motor is a linear motor with transmission linkage.

6. The buffer stop according to any one of claims 1 to 5, wherein the power member is a pressure medium actuated servo adjustment cylinder.

7. The buffer stop according to claims 5 and 6, wherein the servo cylinder is a tandem cyclinder and the control means is designed in such a manner that with the associated buffer stop halves pivoted out of the circular region the piston having the larger effective area is biased first with the pressure medium and subsequently the piston having the smaller effective area.

8. The buffer stop according to any one of claims 1 to 7, wherein the servo motor is disposed beneath a pivot bearing in a counter-sunk arrangement.

9. The buffer stop according to any one of claims 1 to 8, wherein the pivot bearings and the servo motors are supported from a concrete foundation.

10. The buffer stop according to claim 8, wherein the concrete foundation is a one-piece foundation and also supports the drive tracks adjacent the buffer stop.

1 The buffer stop according to claims 8 and 9, wherein the concrete foundation respectively comprises on the outer surface of the associated buffer stop half an open top cavity for the accommodation of the servo motor.

12. The buffer stop according to any one of claims 1 to 11, wherein the buffer stop halves are arranged stationarily and the buffers are attached to the plunger of a hydraulic buffer arrangement.

13. The buffer stop according to claim 12, wherein an automatic return of the plunger into its basic position is provided.

14. The buffer stop according to any one of claims 5 to 13, wherein a central pumping aggregate for several separate buffer stops is provided, preferably accommodated in a protective booth.

15. The buffer stop according to any one of claims 1 to 13, wherein a central control means is provided for several separate buffer stops provided each with a respective servo adjustment drive, having separate actuation means for each buffer stop, and preferably accommodated in a protective booth.

1 6. A buffer stop constructed and arranged substantially as hereinbefore with reference to and as illustrated by the accompanying drawings.