Coupling Device For A Dray

Abstract

In a coupling device for a dray, a device with which one end of the dray can be lifted to rest against the pulling vehicle and which consists of a coupling part of a gooseneck attached to a pulling vehicle at one end and a coupling pocket in the dray meant to receive the gooseneck. The side walls of the gooseneck coupling part and the coupling pocket deviate from the vertical plane and are dimensioned so that, when lifted the slanted side walls of the coupling part of the gooseneck are wedged between the slanted side walls of the coupling pocket so that a pulling coupling is created between the dray and the pulling vehicle.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a coupling device for coupling a dray to a pulling vehicle provided with a gooseneck with which the dray is lifted into the driving position.

2. Description of the Prior Art

A coupling device is known from U.S. Pat. No. 2,389,211, in which a coupling hook is brought into a rectangular notch corresponding to the shape of the hook. The notch and the hook are approximately of the same width, for which reason it is difficult to push the hook in unless the pulling car is in perfect alignment with the longitudinal axis of the coupling noth. The hook is fastened with special locking gears, which lock the hook into the coupling noth and naturally, also, to the chassis of the pulling vehicle in the pulling direction.

German patent 1 297 999 introduces a coupling pocket which has a supporting surface in its upper part in the front and in its lower part in the back. Slanted adjustment surfaces run from the side walls of the coupling pocket toward the frontmost supporting surface, their purpose being to guide the gooseneck of the pulling vehicle to the center of the coupling pocket. The gooseneck of the pulling vehicle can thus be pushed into the coupling pocket in a bevel position in relation to the dray. After this, the locking procedure of the gooseneck is completed with clamps in the pulling direction.

As to the organs for locking the gooseneck into the coupling pocket, it must be noted that they all make the coupling and uncoupling between the dray and the pulling vehicle slow and troublesome. For this reason the users of these devices often change them on their own initiative with the result that the security of the coupling becomes questionable.

SUMMARY OF THE INVENTION

The coupling device of the invention is composed of two interlockable parts, positioned at one end of the gooseneck and the dray respectively, one part being a projection and the other a coupling pocket adapted to receive the projection for supporting the one end of the dray. Both side walls of the interlockable parts are slanted so that the side walls of the projection are wedged between the side walls of the coupling pocket. The coupling device according to the invention may consist of a coupling pocket in the dray and a gooseneck which fits into the pocket. When the dray is used in roll-on-roll-off traffic, in which a loaded dray is hauled onto the ship, transported together with the load, and then hauled off the ship at its destination, it is necessary that the dray be easily attached to the pulling vehicle.

With a device according to the present invention it is possible to attach the gooseneck to the coupling pocket quickly and easily even when the pulling vehicle is not in alignment with the dray. Furthermore, a very good lateral stability of the dray is obtained in the driving position. This is accomplished according to the invention by shaping the cross sections of the gooseneck of the pulling vehicle and the coupling pocket so that the slanted side walls of the gooseneck lean against the slanted side walls of the coupling pocket. Thus, the supporting surfaces are the slanted side walls of the coupling pocket. In this way the gooseneck of the pulling vehicle stays firmly and centrally in place in the coupling pocket. The gooseneck can be guided with even greater precision and fastened even more firmly, if the back part of the gooseneck and respectively the back part of the coupling pocket are provided with slanted side walls which converge downward, that is, in a direction opposite to the converging of the front part of the gooseneck and the front part of the coupling pocket. When the angle formed by these side walls and the vertical plane is 10.degree.-50.degree., such a great frictional force is created at the points of contact between the gooseneck and the side walls, that no locking between the gooseneck and the coupling pocket is necessary. The slanted supporting surfaces being relatively wide compared with the dimensions of the cross section of the gooseneck, the gooseneck is very firmly guided by them during the driving so that the coupling device receives torsional moments which twist the vehicle combination about its longitudinal axis, and the front end of the dray is supported by the chassis and the wheels of the pulling vehicle. Thus, the dray cannot move in the lateral direction. Nevertheless, it is easy to uncouple and couple the dray because there are no locking pieces or thresholds.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a pulling vehicle and a dray uncoupled,

FIG. 2 shows a pulling vehicle and a dray seen from the top,

FIG. 3 is a side view of a pulling vehicle gooseneck according to the invention,

FIG. 3a shows a cross section of the gooseneck along line A--A in FIG. 3, or at the first supporting surface,

FIG. 4 is a side view of the coupling pocket of the dray,

FIG. 5 is a side view of the coupling of the gooseneck into the coupling pocket,

FIG. 5a shows a cross section of the front parts of the gooseneck and the coupling pocket along line B--B in FIG. 5, and

FIG. 5b shows a cross section of the back parts of the gooseneck and the coupling pocket along line C--C in FIG. 5,

FIG. 6 is a side view of a gooseneck according to another application of the invention,

FIG. 6a shows a cross section of the front part of the gooseneck along line A--A in FIG. 6,

FIG. 6b shows a cross section of the back part of the gooseneck along line B--B in FIG. 6, or at the hindmost supporting surface.

FIG. 7 shows a dray coupling pocket to which is coupled a gooseneck according to the second example of the invention,

FIG. 8 is a side view of the fitting of a gooseneck according to FIG. 6 into a coupling pocket according to FIG. 7,

FIG. 8a shows a cross section of the front parts of the gooseneck and the coupling pockets along line C--C in FIG. 8, and

FIG. 8b shows a cross cut of the back parts of the gooseneck and the coupling pocket along line D--D in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1, 1 refers to the gooseneck of the pulling vehicle and 2 to the gooseneck coupling part, which is pushed into coupling pocket 4 of dray 3, when the pulling vehicle is coupled to the dray. As shown in FIG. 2, the mouth of coupling pocket 4 is somewhat wider than its back part, which makes it possible to couple the pulling vehicle to the dray even when the pulling vehicle and the dray are not in perfect alignment. Respectively, the back end of gooseneck coupling part 2 is narrower than its front part. As shown in FIG. 3, lower surface 10 of gooseneck coupling part 2 is slanted upward to facilitate the fitting of gooseneck 2 into the coupling pocket. Respectively, lower surface 7 of coupling pocket 4 is slanted upward. The cross section of gooseneck 2 is approximately triangular as shown in FIG. 3a so that lower surface 10 of the gooseneck is wider than its upper surface 9. The slanted side walls may form an angle of 10.degree.-45.degree. with the vertical plane. The cross section of coupling pocket 4 is also triangular.

When dray 3 is coupled to the pulling vehicle, gooseneck 2 is pushed into coupling pocket 4, which is easy even when the pulling vehicle and the dray are not in perfect alignment, since the mouth of the coupling pocket is somewhat wider than its back part. Thanks to slanted lower surface 10 of gooseneck 2, gooseneck 2 slides easily into coupling pocket 4 into the position shown in FIG. 5. When dray 3 is lifted into the driving position, gooseneck 2 is lifted somewhat, at which time slanted sides walls 6 of gooseneck 2 are wedged very easily into the space formed by slanted side walls 15 of coupling pocket 4 (FIG. 5a), and the dray moves sideways so that its center line is directed toward the joint of the gooseneck in the pulling vehicle. As shown in FIG. 5a, a small crevice is left between gooseneck 2 and upper wall 8 of coupling pocket 4 when gooseneck 2 is coupled to coupling pocket 4. Lower surface 10 of the back part of gooseneck 2, again, is in contact with lower wall 7 of coupling pocket (FIG. 5b).

A coupling device according to another application of the invention is shown in FIG. 6. In this example, gooseneck 2 also has slanted lower surface 10 to facilitate pushing the gooseneck in. The cross section of gooseneck 2 changes at point 11 so that back part 12 of gooseneck 2 converges downward as shown in FIGS. 6a and 6b. Respectively, the cross section of coupling pocket 4 changes, at point 14 in FIG. 7, from a downward widening shape into a downward converging one. When gooseneck 2 is fitted into coupling pocket 4 according to FIG. 8, a double wedging is created between gooseneck 2 and slanted side walls 16 of coupling pocket 4. When gooseneck 2 is lifted into the driving position, slanted side walls 6 of the front part of gooseneck 2 come into firm contact with the side walls of coupling pocket 4, while slanted side walls of back part 12 of gooseneck 2 are pressed downward against the respective slanted side walls of coupling pocket 4. Both in the front and back parts of gooseneck 2 a small crevice is left between the gooseneck and the upper and lower walls of the coupling pocket, as shown in FIGS. 8a and 8b.

Claims

What is claimed is:

1. In a coupling device for a dray a first coupling means at one end of a gooseneck which gooseneck is attached to a pulling vehicle at one end thereof and a second coupling means attached to one end of the dray, in which one of the first and second coupling means is a projection and the other a coupling pocket adapted to receive the projection for supporting said one end of the dray and in which the first and second coupling means have slanting side walls deviating from the vertical plane and dimensioned so that, when lifted, the slanted side walls of the projection are wedged between the slanted side walls of the coupling pocket in order to create a pulling coupling between the dray and the pulling vehicle.

2. The coupling device of claim 1, wherein the side walls of the projection and the coupling pocket converge upward at the end closest to the pulling vehicle and downward at the other end.

3. The coupling device of claim 1, wherein the side walls of the projection and the coupling pocket converge upward.

4. The coupling device of claim 1, wherein the first coupling means at one end of the gooseneck is the projection and the second coupling means at the one end of the dray is the coupling pocket.

5. The coupling device of claim 1, wherein the slanted side walls of the projection and the coupling pocket respectively form an angle of from 10.degree. to 45.degree. with the vertical plane.