GB2154972A

GB2154972A - An automatic coupling for a towed vehicle

Info

Publication number: GB2154972A
Application number: GB08505210A
Authority: GB
Inventors: Wolfgang Wiebelhaus; Barun Chatterjee; Jurgen Meede
Original assignee: Bergische Stahl Industrie
Current assignee: Bergische Stahl Industrie
Priority date: 1984-03-01
Filing date: 1985-02-28
Publication date: 1985-09-18
Also published as: FR2560576A1; FI80642C; GB8505210D0; DK160242B; DE3407526A1; BE901851A; DK87585D0; IT8547743A0; FI850799A0; DE3407526C2; FI850799L; IT8547743A1; FR2560576B1; GB2154972B; DK87585A; FI80642B; IT1181756B; DK160242C; ES284855U; ES284855Y

Abstract

An automatic coupling, especially for a rail vehicle with a traction hook, comprises a catcher throat (12) and two long levers (13, 14) for engaging the traction hook and pivotable about vertical axes (15) into the catcher throat. At least one of the levers (13, 14) has an abutment (16) which, in the open setting of the levers, projects into the throat (12). The end portions (13A, 14A) of the levers (13, 14) are prolonged rearwardly beyond the axles (15) and each have a respective one of two mutually facing stop surfaces (21). The levers (13, 14) are held in the open setting by a spring (20), and a locking block (22) is insertable between the stop surfaces (21) in the closed setting of the levers. The locking block (22) may be movable by manual, electric, hydraulic, or pneumatic means. <IMAGE>

Description

SPECIFICATION An automatic coupling for a towed vehicle The present invention relates to an automatic coupling for a towed vehicle, especially a rail vehicle.

An automatic shunting coupling is known from DE-OS 27 45 158, in which a respective lug projects on each side of and into a catcher throat and is pivotably mounted in a horizonatal plane at one or both sides, the lug being held in the pivoted-in setting by a spring. A traction hook moving into the throat presses open the pivotable lug, which, after the inward movement of the hook, returns to the initial setting and thereby latches and retains the hook in the catcher throat, whereby the coupling operation is concluded. A disadvantage of this coupling is that coupling can no longer be carried if the spring pressing the lugs into the pivoted-in setting fails, because the lug pressed into the open setting during the inward movement of the hook no longer returns to the coupling setting.Moreover, clamping of the pivotable lug can be obstructed by external influences, such as dirt, ice and so forth, so that the lug moves back into open setting and does not effect a coupling.

In addition, a shunting coupling is known from DE-OS 32 04 406, in which two tong levers, which are pivotable about a common axis, form a coupling eye, wherein the entire part, which carries the tong levers, of the coupling must be displaced until this part connects by hooks with the articulating member. The disadvantage of this coupling consists in its relatively expensive construction and the locking of the coupling part with the articulating member requires a relatively hard impact of the vehicles to be coupled.

It would thus be desirable to avoid the disadvantages of the known couplings and create an automatic coupling which has relatively few movable parts, but can be moved without additional forces by a hook to be coupled, whereby the coupling operation can be securely effected.

According to the present invention there is provided an automatic coupling for a towed vehicle, comprising means defining a catcher throat for a tow hook, two double-arm tong levers pivotable between a closed setting in which first arms of the levers project into the throat to retain such hook therein and an open setting in which the arms release the hook, at least one of the levers being provided with an abutment which in the open setting of the levers is disposed in the throat to be so engageable by such hook on movement thereof into the throat as to cause the levers to be pivoted against a resilient bias into the closed setting and each of the levers being provided on its second arm with a stop surface which in the closed setting of the levers is disposed at a spacing from and faces the respective other stop surface, and a stop element positionable between the stop surfaces in the closed setting of the levers to prevent movement thereof into the open setting.

In a preferred embodiment, the second arms of the levers are provided by end portions prolonged rearwardly beyond vertical axles and each having a respective one of two mutually facing surfaces which lie parallelly to the axles and, in the closed setting of the levers, parallelly to each other at a spacing, the levers being held in the open setting by springs.

Expediently, only one lever possesses an abutment and is connected through a cross link with the other lever in the sense of a movement closing the levers.

Advantageously, the stop element is articulated to a hand lever which is pivotable about one end thereof and which is, for example, pressed by springs into the closed setting of the stop element. The hand lever can be movable by drive means, for example a hydraulic piston-cylinder unit, a pneumatic piston-cylinder unit or an electric setting motor, into open setting.

A coupling embodying the invention may have the advantage of being constructed from relatively few parts and arranged to largely eliminate various sources of fault. it may be able to operate reliably evqn if all springs are broken. Thus the hook can' move out of the coupling setting even when the springs pulling the levers into the open setting are broken, because the levers move automatically under tension at the hook. On the other hand, only a fracture of a lever can open the coupling when the stop element is between the stop surfaces. Moreover, the stop element can be so arranged as to be moved into the closed setting solely through gravity.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Figure 1 is a partially sectional side elevation of a coupling embodying the invention; and Figure 2 is a cross-section along the line Il-Il of Fig. 1.

Referring now the drawings, there is shown a coupling- comprising a carrier plate 11, at the front side of which is arranged a catcher throat 1 2. Two tong levers 1 3 and 14 are provided in the plate 11 to be pivotable about vertical bolts 1 5. The lever 14 has an abutment 1 6 for a traction hook which is to be coupled. A cross lever 1 7 is articulated on one hand to a bolt 18 at the lever 14 and on the other hand to a bolt 1 9 at the lever 1 3, whereby the movement of the lever 1 4 is constrainedly so transmitted to the lever 1 3 that both levers simultaneously execute move ments opening and closing the tongs.If the lever 14 is thus moved into open setting, then the lever 1 3 is also pivoted into open setting by way of the cross lever 17 and conversely.

At the end portions 1 3A and 14A, which are prolonged rearwardly of the bolts 15, of the levers 1 3 and 14, the two levers are interconnected by a tension spring 20, which stands under tension in the closed setting of the levers (Fig. 2). Each of the end portions 1 3A and 14A has a vertical surface 21, which lies parallel to the bolts 1 5. In the closed setting of the levers 13 and 14, the surfaces 21 are disposed at a spacing Z and lie parallel to and opposite each other. Inserted between the surfaces 21 in the closed setting of the levers 1 3 and 14 is a locking block 22, the width of which is only little less than the spacing Z.

The locking block 22 is articulated by a bolt 23 to a hand lever 24 arranged on the coupling. The hand lever 24 is pivotably mounted at one end by a bolt 25 in the coupling to be vertically movable and is urged by springs 26 into the setting which is illustrated in Fig. 1 and in which the locking block 22 lies between the surfaces 21. A hydraulic or pneumatic piston cylinder unit 27 or an electric setting motor is arranged below the hand lever 24 vertically at the rearward end of the coupling.

For placing the coupling into operation, pressure is created in the cylinder of the unit 27, whereby the hand lever 24 is pivoted upwardly and in that case draws the locking block 22 out from between the surfaces 21.

When this movement is completed, the two levers 1 3 and 14 are pulled by the spring 20 into open setting, whereby the forward ends of the levers pivot away to the side and the abutment 1 6 is moved into the throat 1 2. The coupling is now ready for operation.

If the coupling is driven against a traction hook or the hook against the coupling, then the hook is caught in the catcher throat 1 2 and so guided that it impinges against the abutment 1 6 and moves this abutment 1 6 rearwardly until the hook impinges on the rearward end of the throat 1 2. Through this displacement of the abutment 16, the lever 1 4 is moved around the bolt 1 5 into the closed setting (Fig. 2), whilst the layer 1 3 is simultaneously pivoted into the closed setting by the cross lever 17.When the closed set ting of the levers 1 3 and 14 is reached, then the surfaces 21 at the rearward end portions 1 3A and 1 4A of the levers will be disposed at the spacing Z from each other and the locking block 22, which as stated has a somewhat smaller width than the spacing Z, is urged between the surfaces 21 by the springs 26 acting on the hand lever 24. The coupling operation is now completed, because the levers 1 3 and 14 both project into the throat of the hook and thus form a coupling eye which holds the hook. The levers 1 3 and 14 cannot be opened by tension at the hook, because opening is prevented by the locking block 22.

For opening of the coupling, it is only necessary to pivot the hand lever 24 upwardly either by hand or by way of the unit 27 or setting motor, whereby the locking block 22 is drawn out from between the surfaces 21 so that the spring 20 pulls both the levers 1 3 and 14 a part and frees the coupled hook.

However, even if the spring 20 were broken, the hook would under tension pivot the levers 1 3 and 14 into the open setting, because the pivot axles 1 5 of the levers lie outside the line of action of th force. In the opened setting of the coupling, the locking block 22 bears on the end portions 1 3A and 1 4A of the tong arms under the influence of the springs 26.

The coupling is now again ready for coupling.

Although the force of the spring 20 can be set in known manner, the coupling is always opened when the locking block 22 is drawn out from between the surfaces 21. The levers 13 and 14 then go into the open setting on outward movement of the traction hook and remain there so that the coupling remains ready for coupling even if the spring 20 is broken.

The locking block 22 can also carry means by which the tong levers are held in open setting in non-self-locking manner, for example through ramp surfaces on the tong levers and the underside of the locking block, which in the case of a broken spring 20 prevents the levers from moving into the closed setting on their own due to the shaking movements of the vehicle during travel.

The locking block 22 can also be moved in another plane between the surfaces 21, for example pivoted in from the rear.

Either or both surfaces 21 can be arranged to be slightly aslant and the corresponding surfaces of the locking block 22 similarly aslant, thus parallelly to the surfaces 21. In order to avoid -self-locking, which would prevent withdrawal of the locking block 22, an abutment can be provided for the hand lever 24 or the locking block 22 to ensure that the latter is pushed between the surfaces 21 to an extent sufficient to still leave a small play between the surfaces 21 and the corresponding surfaces of the locking block, so that selflocking cannot occur. If this abutment is constructed to be resettable, then, in the event of wear, the degree of insertion of the locking block 22 can be adjusted so that the levers 1 3 and 14 are always closed as far as possible.

Normally, the hook is held by the shape of the catcher throat in the coupling tongs and cannot move out downardly.

Claims

1. An automatic coupling for a towed vehicle, comprising means defining a catcher throat for a tow hook, two double-arm tong levers pivotable between a closed setting in which first arms of the levers project into the throat to retain such hook therein and an open setting in which the arms release the hook, at least one of the levers being provided with an abutment which in the open setting of the levers is disposed in the throat to be so engageable by such hook on movement thereof into the throat as to cause the levers to be pivoted against a resilient bias into the closed setting and each of the levers being provided on its second arm with a stop surface which in the closed setting of the levers is disposed at a spacing from and faces the respective other stop surface, and a stop element positionable between the stop surfaces in the closed setting of the levers to prevent movement thereof into the open setting.

2. A coupling as claimed in claim 1, wherein said one of the levers is coupled to the other lever by a link which translates movement of the one lever into opposite movement of the other lever.

3. A coupling as claimed in either claim 1 or claim 2, wherein the resilient bias is provided by a tension spring connected to the second arms of the levers.

4. A coupling as claimed in claim 3, comprising means to adjust the force of the spring.

5. A coupling as claimed in any one of the preceding claims, wherein the stop element is pivotably connected to a hand lever which is pivotable to move the element into and out of a position between the stop surfaces.

6. A coupling as claimed in claim 5, comprising a drive means operable to drive the hand lever for movement of the stop element out of said position.

7. A coupling as claimed in claim 6, the drive means being one of a hydraulic pistoncylinder unit, a pneumatic piston-cylinder unit and an electric motor.

8. A coupling as claimed in any one of claims 5 to 7, comprising resilient means urging the hand lever into a setting in which the stop element is disposed between the stop surfaces.

9. A coupling as claimed in any one of the precedng claims, wherein the stop surfaces are substantially parallel to axes of pivotation of the tong levers and in the closed setting of the levers are disposed substantially parallelly to each other.

10. A coupling as claimed in any one of claims 1 to 8, wherein the stop element has a respective surface associated with and arranged in a plane substantially parallel to each of the stop surfaces, at least one of the stop surfaces being disposed in a plane which, in use, is inclined to the vertical.

11. A coupling as claimed in claim 10, comprising means to set a selectable extent of projection of the stop element between the stop surfaces.

1 2. A coupling substantially as hereinbefore described with reference to the accompanying drawings.

1 3. A rail vehicle provided with a coupling as claimed in any one of the preceding claims.