GB1558709A

GB1558709A - Ball-jount couplings

Info

Publication number: GB1558709A
Application number: GB30540/77A
Authority: GB
Original assignee: Paulstra SNC
Current assignee: Paulstra SNC
Priority date: 1976-07-21
Filing date: 1977-07-20
Publication date: 1980-01-09
Also published as: BE856982A; FR2359000A1; IT1079351B; FR2359000B1; NL7708065A; NL166650C; CH614667A5; DK329777A; SE7708365L; DK143644C; NO772504L; DE2732345C2; DE2732345A1; DK143644B; LU77812A1

Description

(54) IMPROVEMENTS IN OR RELATING TO BALL-JOINT COUPLINGS (71) We, PAULSTRA, a French Body Corporate, of 61 Avenue Marius-Aufan, 92305, Levallois-Perret, France, 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: This invention relates to balljoint couplings of the kind used between a traction vehicle and a trailer, more particularly, but not exclusively, devices of the kind in which the ball joint is made resilient by inserting at least one layer of elastomer between the ball and a cap which partially covers it.

The main object of the invention is to simplify the components of the coupling required at the rear of the traction vehicle, so as to eliminate dangerous components on the rear of the vehicle after the trailer is uncoupled, and to simplify the entire coupling while increasing its reliability, in that the ball diameter can be increased.

According to the invention, there is provided a coupling for connecting two vehicles together, including a ball joint for mounting on one vehicle and a connecting block for mounting on the other vehicle, the ball joint having a ball with a tongue projecting therefrom, the connecting block having a recess for receiving the tongue, in which coupling the tongue is platelike and has edge surfaces for wedging engagement with complementary surfaces of the recess in the connecting block and the coupling includes means for holding the edge surfaces of the tongue and the complementary surfaces of the recess in wedging engagement Preferably, the tongue is vertically disposed in use and the holding means acts independently of the traction transmitted by the coupling between the vehicles so that the wedging engagement of the tongue is not affected by the traction.

Tn an embodiment of the invention the edge surfaces of the tongue and the complementary surfaces of the recess are each inclined with respect to two orthogonal directions so that double wedging is produced between each edge surface of the tongue and the respective complementary surface of the recess.

Conveniently, the connecting block is constituted by an asselmbly of two flat components defining therebetween the recess adapted to receive the tongue. The connecting block constructed in this way only projects to a small extent and can therefore safely be mounted at the rear of the traction vehicle.

Preferably, the holding means is constituted by a key for driving the tongue into the recess. In an embodiment, the key extends into the connecting block transversely of the recess, the key having an indentation for enabling free insertion of the tongue into the recess with the key in its inoperative position and a step for co-operating with a groove formed in the tongue to press the tongue into wedging engagement in the recess on movement of the key into its operative position. Desirably, the coupling includes a locking pin which is engageable in the said indentation in the operative position of the key.

The ball of the ball joint may be covered with rubber and is clamped between two flanged members by means of clamping bolts. Conveniently, the clamping bolts are secured to a handle for manipulating the coupling.

In order that the invention may be readily understood, an embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: FIGURE 1 is a perspective view, prior to assembly, of a resilient ball-joint coupling embodying the invention and used between the rear of a traction vehicle and a trailer pole (or any comparable member), e.g. a pole secured to an inertia brake; FIGURE 2 is a vertical section through the coupling along the line II-II in Figure 1, more particularly illustrating the operation of a securing key of the coupling, FIGURE 3 is a perspective view of the main components of the coupling which are provided at the rear of the traction vehicle; and FIGURE 4 is a vertical section through the aforementioned elements, showing the operating positions of the key.

Referring to the drawings, a resilient balljoint is constructed so that it can be secured to a front portion (e.g. a plate 2) of a trailer pole 1. A ball 4 (Figure 2) of the joint is provided with a tongue 3 adapted to engage in a recess 17 in a connecting block 18, 21 provided at the rear of the traction vehicle, the tongue being held therein by a key 24.

Tb suhstantially spherical, metal ball 4 is introduced between two elements 5, 6 of a socket in which the ball is gripped with the interposition of a pre-compressed layer of rubber 7 (Figure 2).

Elements 5 and 6 are e.g. flanged members which, at their centres, comprise respective part-spherical caps adapted to surround the rubber 7, the flanges being formed with lateral apertures for bolts 9 which, in combination with nuts or other means 10, prestress the rubber 7 and simultaneously secure the ball-joint coupling assembly to the plate 2 which is integral with the pole 1.

The rubber may be made adhesive, though this is not essential.

The tongue 3 is offset forwardly of the vertical axis of the ball 4, as shown in Figure 1 and 2, where the operative portion 3 of the tongue is connected to the ball 4 by a double bend portion 11.

In order to hold the trailer at a constant inclination, in the vertical plane, with respect to the traction vehicle, free passages are formed between a neck 12, at which the tongue is attached to the ball 4, and the socket formed by the aforementioned two members 5, 6. Accordingly, as shown in Figure 2, the members 5, 6 have suitable clearances 13 at the neck 12.

The coupling also comprises a handle 14 for manipulation during the coupling and uncoupling operations. Advantageously the handle is integral with bolts 9. With regard more particularly to the operative portion 3 of the tongue and the means reauired on the traction vehicle for removably securing the tongue, the construction is as follows.

Tongue 3 has a flat platelike shape. The lateral edges 15 of each major surface of the tongue are at a smalls angle a to one another, whereas the two lateral edge surfaces 16 are at an angle P to one-another, the assembly being adapted to be introduced into a correspondingly-shaped recess 17 formed in the connecting block at the rear of the traction vehicle.

The recess 17 (Figures 1, 3 and 4) is formed in a securing plate I8 adapted to be fixed, e.g. by screws 19 and washers 20, to a component 21 to- form the connecting block. The component 21 is secured to the frame 22 of the traction vehicle (Figure 3). Component 21 is e.g. in the form of a flat plate which the recess 17 confronts.

The side surfaces 23 of recess 17 are complementary to the lateral edge surfaces 16 of tongue 3 and thus have the same inclinations a and p as the corresponding lateral edge surfaces 16 of tongue 3. When the tongue 3 is pushed into the recess 17 in the direction indicated by arrow F in Figures 1 and 2, it thus tends to become wedged in the recess 17 by wedging engagement of surfaces 16 and 23.

During the coupling operation, the aforementioned motion in the direction F can be produced by various methods, e.g. by using a suitably-shaped key 24 which extends transversely through recess 17 in a suitable groove 25 formed in plate 18 at right angles to the average direction of recess 17. The surface of tongue 3 facing the key has a transverse groove 26, the purpose of which will be explained hereinafter.

Key 24 has a generally flattened shape adapted to the cross-section of transverse grooves 25 and 26, but its height h is slightly less than the height H of the grooves. In addition, height h varies slightly from one end of the key to the other.

At the beginning of a keying operation, the key is in the groove, in an inoperative position determined by - a stop 27 (Figures 1 and 4) on the key. The key has an indentation 28 which, in the aforementioned inoperative position of the key is in vertical alignment with recess 17 and is sub- stantially at the same depth as recess 17.

A second shallower clearance follows clearance 28 and forms a step 29.

The assembly operates as follows: During the coupling operation, the connecting block 18, 21 and key 24 appear as shown in Figure 4, in which the stop 27 of the key bears against its abutment, so that clearance 28 is in vertical alignment with recess 17 and tongue 3 can be freely inserted, using handle 14 to bring the bottom end of the tongue opposite recess 17.

After the tongue has been inserted, the key is moved (using a-hammer or weight or in any other suitable manner) in the transverse direction G, which tends to move stop 27 away from its abutment.

Step 29 then makes contact with groove 26 in tongue 3, the top surface 30 of key 24 bearing against the corresponding surface 25 of groove 25 of plate 18 (Figure 2) and the bottom surface 31 of key 24 bearing against the corresponding surface 26, of groove 26 in tongue 3 (Figure 2). The tongue is thus firmly moved in the direction F, since the height h between sides 30 and 31 increases in the opposite direction to the direction of movement G.

Finally, an operative wedging pdsition of the key is obtained which reliably retains the tongue 3 in the recess 17.

Any other kinematic means for driving in and securing tongue 3 can be used.

Safety means may be provided to prevent the key from being prematurely withdrawn.

In the embodiment shown, the safety means comprise a locking pin such as 32 adapted to be inserted in that part of clearance 28 which, as a result of the movement of key 24 in the direction G, projects outside plates 18 and 21, as shown in Figure 4.

The device is uncoupled by reversing the previously-described operations, i.e. by extracting pin 32, then by moving key 24, using a hammer or weight, in the direction opposite to G until it reaches the rest position, and finally by extracting tongue 3 by means of handle 14.

Of course a safety cable can be provided between plates 18, 21 on the one hand and pole 1, 2 on the other hand, in known manner.

Compared with existing couplings of the same kind, a coupling embodying the invention has numerous advantages, including the following: The elimination of dangerous components at the rear of the tractor, since the tractor comprises only a very simple assembly made up of plates 18, 21 and key 24, as shown in Figure 3.

The construction of the ball-joint and its tongue are greatly simplified.

The tongue is secured to the tractor in a very efficient manner, without friction and without cause for wear or clearance.

If required, the diameter of the ball joint can be increased.

WHAT WE CLAIM IS:- 1. A coupling for connecting two vehicles together, including a ball joint for mounting on one vehicle and a connecting block for mounting on the other vehicle, the ball joint having a ball with a tongue projecting therefrom, the connecting block having a recess for receiving the tongue, in which coupling the tongue is platelike and has edge surfaces for wedging engagement with complementary surfaces of the recess in the connecting block and the coupling includes means for holding the edge surfaces of the tongue and the complementary surfaces of the recess in wedging engagement.

2. A coupling according to claim 1, wherein, in use, the tongue is vertically disposed and the holding means acts independently of the traction transmitted by the coupling between the vehicles.

3. A coupling according to claim 1 or 2, wherein the edge surfaces of the tongue and the complementary surfaces of the recess are each inclined with respect to two orthogonal directions so that double wedging is produced between each edge surface of the tongue and the respective complementary surface of the recess.

4. A coupling according to any one of claims 1 to 3, wherein the connecting block is constituted by an assembly of two flat components defining therebetween the recess adapted to receive the tongue.

5. A coupling according to any preceding claim, wherein the holding means is constituted by a key for driving the tongue into the recess.

6. A coupling according to claim 5, wherein the key extends into the connecting block transversely of the recess, the key having an indentation for enabling free insertion of the tongue into the recess with the key in its operative position and a step for co-operating with a groove formed in the tongue to press the tongue into wedging engagement in the recess on movement of the key into its operative position.

7. A coupling according to claim 6, including a locking pin which is engageable in the said indentation in the operative position of the key.

8. A coupling according to any preceding claim, wherein the ball of the ball joint is covered with rubber and is clamped between two flanged members by means of clamping bolts.

9. A coupling according to claim 8, wherein the clamping bolts are secured to a handle for manipulating the coupling.

10. A ball joint coupling substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. of the key is obtained which reliably retains the tongue 3 in the recess 17. Any other kinematic means for driving in and securing tongue 3 can be used. Safety means may be provided to prevent the key from being prematurely withdrawn. In the embodiment shown, the safety means comprise a locking pin such as 32 adapted to be inserted in that part of clearance 28 which, as a result of the movement of key 24 in the direction G, projects outside plates 18 and 21, as shown in Figure 4. The device is uncoupled by reversing the previously-described operations, i.e. by extracting pin 32, then by moving key 24, using a hammer or weight, in the direction opposite to G until it reaches the rest position, and finally by extracting tongue 3 by means of handle 14. Of course a safety cable can be provided between plates 18, 21 on the one hand and pole 1, 2 on the other hand, in known manner. Compared with existing couplings of the same kind, a coupling embodying the invention has numerous advantages, including the following: The elimination of dangerous components at the rear of the tractor, since the tractor comprises only a very simple assembly made up of plates 18, 21 and key 24, as shown in Figure 3. The construction of the ball-joint and its tongue are greatly simplified. The tongue is secured to the tractor in a very efficient manner, without friction and without cause for wear or clearance. If required, the diameter of the ball joint can be increased. WHAT WE CLAIM IS:-

1. A coupling for connecting two vehicles together, including a ball joint for mounting on one vehicle and a connecting block for mounting on the other vehicle, the ball joint having a ball with a tongue projecting therefrom, the connecting block having a recess for receiving the tongue, in which coupling the tongue is platelike and has edge surfaces for wedging engagement with complementary surfaces of the recess in the connecting block and the coupling includes means for holding the edge surfaces of the tongue and the complementary surfaces of the recess in wedging engagement.