GB1559127A

GB1559127A - Locking divece for semi-trailer coupling

Info

Publication number: GB1559127A
Application number: GB3100576A
Authority: GB
Original assignee: DELTA METALL FAHRZEUGTECH
Current assignee: DELTA METALL FAHRZEUGTECH
Priority date: 1975-09-26
Filing date: 1976-07-26
Publication date: 1980-01-16

Description

(54) LOCKING DEVICE FOR SEMI-TRAILER COUPLING (71) We, DELTA METALL- UND FAHRZEUGTECHNIL GMBH, Hauffstrasse 2, 8000 Munched 70, Federal Republic of Germany, a German body corporate, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a fifth-wheel coupling comprising a plate including a slot which has an open and a closed end and is adapted to receive a coupling pin of a semi-trailer, and pivotally mounted coupling hook adapted to hold the pin in the slot. The open end of the slot usually outwardly widens. In the coupled position the coupling pin bears against a semicircular end portion of the closed end of the slot and is approximately in the centre of the plate. Locking of the coupling hook may take place either by means of a cross latch or a pivotal locking member.

The components mainly subjected to wear in such a locking system comprise the coupling hook and the semi-circular bearing surface of the slot. In an endeavour to effect repairs after wear had taken place in the cheapest possible manner, it has been proposed to provide the semi-circular bearing surface of the slot in the form of an interchangeable segment. However, this entails for constructional reasons an increase of manufacturing tolerances, which is undesirable since the locking system already comprises a number of surfaces, the manufacturing tolerances of which are cumulative, which may even in the new condition result in an undesirable degree of play of the coupling pin. Moreover, the interchangeable wear segment results in structural weakening.

The effects of increased tolerances are avoided whilst simultaneously provision is made for adjustment after wear has taken place if in accordance with a further proposal, the locking member for the coupling hook is designed as wedge-shaped transverse latch.

The locking member, depending on the degree of wear, is pushed more or less closely against the coupling hook, causing the latter to be closed to a greater or lesser degree. However, in practice it is found that the wedge-shaped locking member tends to jam, rendering the release of the locking mechanism when opening the lock of the coupling difficult, and in addition increasing the wear of the coupling pin. In addition, the wedge surface is subjected to a component of force in the direction of opening, which causes an increase m load on the components which safeguard against automatic opening and which result in wear of these components which are essential for the safety in operation of the coupling. Other couplings therefore incorporate the proposal to hold the coupling hook at one end by means of a parallel latch and to render its mountings adjustable. For this purpose an eccentric mounting pin is provided, which permits a stage-wise cross-sectional reduction of the lock. However, this involves a transverse displacement of the centre of mounting, as a result of which the bearing surface of the coupling hook in engagement with the coupling pin, suffers a corresponding displacement. Accordingly, this item when repairs are effected, must be readjusted to the new contact conditions by regrinding, as a result of which couplings of this construction are not truly readjustable without additional operations.

It would be most desirable to mitigate or eliminate the aforesaid disadvantages and to provide a locking system for a coupling which, by virtue of its construction permits manufacture at reasonable cost whilst maintaining narrow manufacturing tolerances, permitting readjustment when wear takes place and moreover, making possible repairs with a saving in costs.

Also desirable is the easy operation of the locking mechanism without jamming of the locking member and the keeping away of operative loads from the safety devices of the operating members.

The invention provides a fifth-wheel coupling comprising a plate including a slot which has an open and a closed end and is adapted to receive a coupling pin of a semi-trailer, a coupling hook pivotally mounted about a first pivot and adapted to hold in its closed position the coupling pin and to be locked in said closed position by a locking latch which is spring-loaded and mounted pivotally about a second pivot, the hook and latch being mounted on the plate, the two pivots being mounted in the plate on opposite sides of the slot in the vicinity of the closed end thereof, the second pivot being mounted for eccentric adjustment.

In a preferred embodiment the coupling includes means for repeated adjustment of the second pivot and for securing it in the adiusted position.

Preferably the plate is mounted to a body of the coupling releasably.

In another preferred embodiment the second pivot has a bolt with a head provided with notches or holes engageable by a stop member.

Various forms of coupling embodying this invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Fig. 1 shows the locking installation below the fifth-wheel plate in the closed position: Fig. 2 is a partial elevational view of the mounting of the locking latch; Fig. 3 shows the locking installation, including the operating members in a released position ready for uncoupling: Fig. 4 shows the locking installation in the open position after the withdrawal of the coupling pin; Fig. S shows the mounting of the locking latch in section: Fig. 6 is a partial plan view of the coupling Fig. 7 shows an alternative embodiment of the mounting of the locking latch: Fig. 8 shows an arresting device in- a closed arrested position, with part of the body of coupling. viewed in a direction onto the sectionalised traction rod of the operating means; Fig. 9 shows the same portion of the coupling in plan; Fig. 10 is a section along the line A-A in Fig. 9: Fig. 11 is a section along the line B-B in Fig. 9; Fig. 12 is a section along the line C-C in Fig. 9; Fig. 13 is an elevation corresponding to Fig. 8 after the release of the locking system; Fig. 14 is a view corresponding to Fig.

9, after the release of the locking system; and Fig. 15 is a section along the line B-B in Fig. 9 after the release of the locking system.

Referring to the drawings, a plate 1, in which the mountings for the locking components and also the guiding surface for the coupling pin 6 are combined, is appropriately connected to the body (not illustrated) of the fifth-wheel coupling mounted on a towing vehicle. In the illustrated embodiment the plate 1 is connected by means of mounting bolts 2, whereby the plate 1 is rendered interchangeable.

These bolts 2. are, for convenience, illustrated in Fig. 1 only.

A coupling hook 3, which by means of a bolt 4 is pivotally mounted at one side of the slot 5. holds the coupling pin 6 of the semi-trailer in the locked position. The bolt 4 is mounted at one end in the plate 1 and at the other end in a supporting plate 7 (Fig. 5) which in the illustration according to Fig. 1, has been removed for greater clarity. The coupling hook 3 on that arm thereof which embraces the coupling pin 6, comprises a surface 8 which is held by a locking latch 9. The locking latch 9 is pivotally mounted by means of a mounting bolt 10 on that side of the slot 5 which is opposite to the mounting bolt 4. The mounting is slightly offset in the direction of travel relative to the position of the bolt 4, i.e. in the upward direction in the illustration according to Fig. 1. A lever 12, spring-loaded by a spring 22 in the direction of locking, is pivotally carried by a bolt 11 provided on the locking latch 9 in the region between the mounting bolt 10 and the surface 8. This lever 12 is connected to the operating means illustrated in Fig. 3 and is held at one end in a guide 13.

nvllereas at its opposite end the operating means engage into a bearing aperture 14.

The mounting bolt 10 comprises a cylindrical section 15 (Fig. 5) for engaging the locking latch 9. This cvlindrical section 15 is eccentrically offset in relation to two further cylindrical sections 16 and 17 in axial alignment with one another. The result of this, is that on rotating the mounting bolt 10, the centre of the axis for the mounting of the locking latch 9 is so disnlaced that the coupling hook 3 is held by way of the surface 8 to a greater or lesser extent. The displaceable mounting in the guide 13 makes it possible for the lever 12 to accommodate a positional change of the locking latch 9 without adversely affecting the function of the locking system. In Fig. 2 the mounting bolt 10 is shown in a position corresponding to a more pronounced closure of the locking system as compared with that illustrated in Fig. 1. The comparatively large distance between the surface 8 and the mounting bolt 10 hardly affects the angle at which the locking latch 9 engages the surface 8.

If in spite of this, it is desired to prevent a shifting of the loading centre as a result of such angular change, it is possible to render the surface 8 of slightly convex configuration.

The illustration according to Fig. 3 shows the locking system in its open position, ready for the withdrawal of the coupling pin 6. In this case the locking latch 9 has been opened by pulling the hand lever 18. In the embodiment it was necessary for this purpose first to move the handle 19 in the direction of the arrow from its locked position, in which one contact surface 20 had been in abutment against the stop member 21 of the hand lever 18. After the movement in the direction of the arrow, the handle 19 was pulled against the tension of the spring 22 and moved once again in the direction of the arrow in order to bring the notch 23 into engagement with the projection 24. In this position the locking mechanism is kept open, the locking latch 9 occupying the position illustrated in Fig.

3. The lever 12 is linked to the hand lever 18 by means of a bolt 25.

In the opened position according to Fig.

3, the locking latch 9 releases the surface 8 of the coupling hook 3. On withdrawal of the coupling pin 6, the coupling hook 3 is pivoted about its mounting bolt 4 in the opening direction, whereby the arm 26 of the coupling hook 3 is brought into engagement with the projection 27 of the locking latch 9. Accordingly, the locking latch 9 is pivoted by a further distance in the opening direction and is held in that opened position. This position is illustrated in Fig. 4. By this pivoting of the locking latch 9 the hand lever 18 is similarly slightly moved in the opening direction, whereby the notch 23 is released from the projection 24 by the action of the spring 22.

This position corresponds to the position of readiness for automatic recoupling. If the coupling hook 3 is pivoted into the position according to Fig. 1 by the introduction of a coupling pin 6, the locking latch 9, which is thus again released from the arm 26, can cnce again retum to the position according to Fig.l .

In order to fix the mounting bolt 10 in the correct position for the elimination of play, the simplest solution is (Fig. 5) to provide the head 36 of the bolt 10 with a groove (not shown). Once the correct position for the elimination of play has been determined, it is fixed by a stop member (not shown) engaging the groove and welded to the body 28. This solution is particularly appropriate if the mounting bolt 10 is to be used solely for the correction of manufacturing tolerances. If it is desired to make readjustments during operation, the embodiment illustrated in Fig. 6 will provide for an appropriate step-wise manner of readjustment. Fig. 6 illustrates a view in the direction of the surface of the body 28 of the coupling, approximately half of the circumference of the bolt head 36 being provided with notches 29. A bolt 30 fitted into the plate 1 engages one of these notches 29. After the release of a pin 31 (Fig. 5), the mounting bolt 10 can be withdrawn and be reinstated in any offset position permitted by the notches 29.

A further possibility of continuous adjustability is illustrated in Fig. 7, wherein the illustration corresponds to the view in accordance with Fig. 1, i.e. from the underside of the plate 1. In this construction the end of the mounting bolt 10 is screwed onto a lever 32 carrying a bolt 33 which is pivotally mounted on the lever 32. The bolt 33 comprises a threaded, transverse hole 34. The end of a threaded rod 35 extends into this transverse hole 34, its opposite end, (not illustrated) extending for example to the edge of the body of the coupling where it is mounted rotatably but immovablv in the longitudinal direction. If the threaded rod 35, which in this manner is readily accessible, is tumed, the bolt 33 and thereby the lever 32 are moved along the threads, this resulting in a pivoting movement of the lever 32 which in turn brings about the desired readjustment of the mounting bolt 10.

In the embodiment shown in Fig. 8, the downwardly deflected edge of the body 41 of the coupling is provided with a slot 42, through which the hand lever 43 (18 in Fig.

3) for the operation of the coupling mechanism extends. This lever 43 comprises a stop member 44, which in the locked position, finds support against the body 41. A lifting of the hand lever 43 is prevented bv a transverse latch 45 which passes through bearing means 46 and 47 positioned on opposite sides of the slot 42 and through a further bearing means 51. A stop member 50 is connected to the transverse latch 45 between the bearing means 46 and 47.

The transverse latch 45 terminates in a downwardly deflected handle 53 which, bv gravity maintains the transverse latch 45 in the position of rest illustrated in Figs. 8 to 12. The stop member 50 is so connected to the transverse latch 45 that its axis in the arresting position of rest, is staggered relative to the axis of the transverse latch 45 in the direction of the body 41 (Fig. 10).

In this manner a pressing of the hand lever 43 against the stop member 50 will result in the transverse latch 45 with its handle 53 being pressed against the body 41. This provides additional support for the arresting action of the transverse latch 45, in view of the fact that for unlocking the latter, it is necessary for the handle 53 to be swivelled in an upward direction about the axis of the transverse latch 45 and against the gravitational pull on the handle 53 until the stop member 50 is in alignment with a lateral recess 54 in the central bearing means 47. In that position it is possible for the transverse latch 45 to be displaced to wards the left (according to the illustration in Fig. 8) whereby the transverse latch 45 releases the hand lever 43, permitting the latter to be lifted for the release of the coupling locking system. Accordingly, only the aperture 48 associated with the bearing means 46 and the aperture 52 associated with the bearing means 51, are of cylindrical de sign, whereas the central bearing means 47 is provided with the aforesaid lateral recess 54.

The stop member 50 prevents the com plete withdrawal of the transverse latch 45, the movement of which is restricted bv abutment against the bearing means 51 (Fig. 13). Because the distance between the bearing means 47 and 51 is somewhat less than the distance between the bearing means 47 and 46, the stop member 50 in this withdrawn position is prevented by the recess 54 from being swivelled, thus retain ing the handle 53 in the raised position.

In this manner the unlocked position of the transverse latch 45 is indicated in a conspicuous manner.

In the embodiment illustrated, the bearing means 46, 47 and 51 are formed by a member of undulatory configuration which underneath the slot 42 brings about a reinforcement of the edge of the body. This embodiment offers particular advantages if the additional arresting means are manufactured separately and are fitted subsequently to the body 41, e.g. by welding.

Apart from the desirable reinforcement of the edge of the body in that region which has to arrest the stop member 44 of the hand lever 43 against opening forces, this construction makes possible a particularly economical manufacture, because of the apertures 48, 52 and 54 serving as bearings being first punched into a flat steel member which is then deformed into its final undulatory shape. Above the end which is curved in a hook-shaped manner, there is provided an aperture 55 in the body 41 which for protection against unauthorised operation permits the insertion of a padlock which prevents the upward pivoting of the handle 53.

WHAT WE CLAIM IS:- 1. A fifth-wheel coupling comprising a plate including a slot which has an open and a closed end and is adapted to receive a coupling pin of a semi-trailer, a coupling hook pivotally mounted about a first pivot and adapted to hold in its closed position the coupling pin and to be locked in said closed position by a locking latch which is spring-loaded and mounted pivotally about a second pivot, the hook and latch being mounted on the plate, the two pivots being mounted in the plate on opposite sides of the slot in the vicinity of the closed end thereof, the second pivot being mounted for eccentric adjustment 2. A coupling according to Claim 1 including means for repeated adjustment of the second pivot and for securing it in the adjusted position.

3. A coupling according to Claim 1 or 2, wherein the plate is mounted to a body of the coupling releasably.

4. A coupling according to any one of Claims 1 to 3, wherein the second pivot has a bolt with a bead provided with notches or holes engageable by a stop member.

5. A coupling according to any one of claims 1 to 4, wherein a lever is pivotally connected to the locking latch and finds support at one end in longitudinally movable manner in a guide, whilst its other end comprises a linkage aperture engaged by operating means for the manual actuation of the locking latch.

6. A coupling according to any one of claims 1 to 5, comprising an operating lever, which for its release has to be subjected to an upwardly directed component of movement, and an arresting means for the operating lever, including a transverse latch which is slidable in a horizontal and approximately normal direction to the axis of the operating lever, and is pivotal about the axis of sliding, the transverse latch being fitted to the body of the coupling above the operating lever and comprising a stop member by virtue of which the transverse latch is arrested against sliding in the locked position.

7. A coupling according to claim 6, wherein the stop member is formed by a projection in eccentric relationship to the axis of the transverse latch and the arresting position of which is below the axis of the transverse latch and displaced in the direction towards the body of the coupling.

8. A coupling according to claims 6 and 7, wherein the transverse latch comprises a downwardly deflected handle, the mass of which by gravity counteracts a tendency to

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. to the transverse latch 45 that its axis in the arresting position of rest, is staggered relative to the axis of the transverse latch 45 in the direction of the body 41 (Fig. 10). In this manner a pressing of the hand lever 43 against the stop member 50 will result in the transverse latch 45 with its handle 53 being pressed against the body 41. This provides additional support for the arresting action of the transverse latch 45, in view of the fact that for unlocking the latter, it is necessary for the handle 53 to be swivelled in an upward direction about the axis of the transverse latch 45 and against the gravitational pull on the handle 53 until the stop member 50 is in alignment with a lateral recess 54 in the central bearing means 47. In that position it is possible for the transverse latch 45 to be displaced to wards the left (according to the illustration in Fig. 8) whereby the transverse latch 45 releases the hand lever 43, permitting the latter to be lifted for the release of the coupling locking system. Accordingly, only the aperture 48 associated with the bearing means 46 and the aperture 52 associated with the bearing means 51, are of cylindrical de sign, whereas the central bearing means 47 is provided with the aforesaid lateral recess 54. The stop member 50 prevents the com plete withdrawal of the transverse latch 45, the movement of which is restricted bv abutment against the bearing means 51 (Fig. 13). Because the distance between the bearing means 47 and 51 is somewhat less than the distance between the bearing means 47 and 46, the stop member 50 in this withdrawn position is prevented by the recess 54 from being swivelled, thus retain ing the handle 53 in the raised position. In this manner the unlocked position of the transverse latch 45 is indicated in a conspicuous manner. In the embodiment illustrated, the bearing means 46, 47 and 51 are formed by a member of undulatory configuration which underneath the slot 42 brings about a reinforcement of the edge of the body. This embodiment offers particular advantages if the additional arresting means are manufactured separately and are fitted subsequently to the body 41, e.g. by welding. Apart from the desirable reinforcement of the edge of the body in that region which has to arrest the stop member 44 of the hand lever 43 against opening forces, this construction makes possible a particularly economical manufacture, because of the apertures 48, 52 and 54 serving as bearings being first punched into a flat steel member which is then deformed into its final undulatory shape. Above the end which is curved in a hook-shaped manner, there is provided an aperture 55 in the body 41 which for protection against unauthorised operation permits the insertion of a padlock which prevents the upward pivoting of the handle 53. WHAT WE CLAIM IS:-

1. A fifth-wheel coupling comprising a plate including a slot which has an open and a closed end and is adapted to receive a coupling pin of a semi-trailer, a coupling hook pivotally mounted about a first pivot and adapted to hold in its closed position the coupling pin and to be locked in said closed position by a locking latch which is spring-loaded and mounted pivotally about a second pivot, the hook and latch being mounted on the plate, the two pivots being mounted in the plate on opposite sides of the slot in the vicinity of the closed end thereof, the second pivot being mounted for eccentric adjustment

2. A coupling according to Claim 1 including means for repeated adjustment of the second pivot and for securing it in the adjusted position.

be swivelled from the arrested position.

9. A coupling according to any one of claims 6 to 8, wherein the transverse latch is mounted in a movable manner in three faced bearing means, the central bearing means comprising a widened opening which matches the position of the stop member when the handle is in the raised, swivelled position.

10. A coupling according to claim 9, wherein the bearing means for the transverse latch are formed by a sheet metal member which, in the region of the arresting stop member serves as a reinforcement of the body of the coupling.

11. A coupling according to claim 10, wherein the sheet metal member has been deformed into a wave-shape to form the bearing formations.

12. A coupling according to in claim 1 substantially as described with reference to and as illustrated in Figs. 1 to 5, or Figs. 1 to 5 as modified in Fig. 6, or Figs.

1 to 5 as modified in Fig. 7 of the accompanying drawings.

13. A coupling according to in claim 6, substantially as described with reference to and as illustrated in Figs. 8 to 15 of the accompanying drawings.