The present invention relates to a for gripping at a kingpin designed turntable with coupling mechanisms by means of which a with a kingpin equipped device to be coupled to the turntable is with an appropriate force pulled against the turntable.

Previously have become known turntables and therein incorporated locking plates for kingpins and locking mechanisms matching these, which mechanisms for example by means of a variety of structures are pressed against a kingpin and hereby press the turntable to a position parallel to the bearing plane of the device to be coupled. Examples of these are presented e.g. in the DE patent specification 1101971. The present invention is essentially related to a vertically adjustable turntable and therein incorporated mechanisms for gripping at the kingpin of a mono-axle tractor according to the Finnish patent application FI 894504. The adjusting means incorporated in the turntable according to the invention provide a simple manner, with the aid of an equipment of low manufacturing costs, to accomplish the gripping under traction at the kingpin of a vertically adjustable turntable. As the greatest benefit offered by the invention can be regarded the fact that the tractive force applied to the kingpin can be controlled as desired in a simple manner and through uncomplicated mechanisms. The adjusting elements are of simple construction and their manufacture and assembly is techno-economically profitable.

In the following the invention is described in detail with reference to the figures of the accompanying drawing.

Figure 1 shows a sectional view of a turntable and a thereto related kingpin and a coupling device according to the invention. Figure 2 shows a top view of a turntable according to the invention.

A turntable 1 according to the invention as shown in Fig. 1 comprises a tubular body 2 with sliding bearings 3 and a by these and an hydraulic cylinder 6 guided movable tube 4 at the top end of which a table plate 5 is fixed. The tube 4 comprises a bushing 7 having a female threading which, as shown in the figure, is fixed to the inner surface of the upper part of the tube 4. Further, as shown in the figure, to the

bushing 7 is connected a with a male threading matching the female threading of the bushing 7 equipped and inside appropriately shaped gripping member 8 which at its upper part bears against a web 10 of a kingpin 9. Inside the tube 4, substantially below the lowermost position of the gripping member 8, is fixed a blind flange 12 against whose appropriately shaped downward facing surface bears the cylinder 6 through adjustment of whose stroke the position of the tube 4 in the tubular body 2 and thereby the vertical position of the table 5 are adjusted. The gripping member 8 comprises in its lower part, in accordance with the figure, radially located holes 13 into which it is possible in the right radial position of the hole 13, to project a rotary pin 14 through an aperture 15 in the wall of the tube 4. The width of the aperture 15 in the tube 4 preferably corresponds to the ± 60 degrees of the central angle. The spacing of said radially located holes 13 is preferably ca. 15 degrees or slightly below. In this case the gripping member 8 can be turned from the aperture 15 by means of the rotary pin 14 about 60 degrees at a time. The left hand side of the Fig. 1 presents the situation where the kingpin 9 has been guided to its position and tolerances are provided for between the kingpin 9 and the gripping member 8. The right hand side of the Fig. 1 presents the situation where the gripping member 8 has been turned downwardly and the shape of the upper part of the gripping member 8 bears against a flange 17 of the kingpin 8 causing traction. In accordance with Fig. 2, the table plate 5 is provided with a gap 16 that guides the kingpin 9 of a device 11 in the right position in the turntable 1 according to the invention when the turntable 1 is moved bearing against the downward facing surface of the device 11 in such a manner that the kingpin 9 in the starting situation meets the gap 16. The bushing 7 and the gripping member 8 are also provided with a conveniently shaped gap matching the gap of the table plate 5 so as to guide the kingpin 9 to the right position in the bottom of the gap 16. The gap-like shape of the upper part of the gripping member 8 matches the web 10 of the kingpin 9 and the lower part the flange 17 of the kingpin 9. The kingpin 9 is a standardized element, and its location in the device 11 is standardized accordingly. As a result, the parts 5, 7, 8 connected to the tube 4 of the turntable 1 according to the invention can be shaped accurately in advance and the tolerances required are moderately small. In Fig. 2 the position of the gap of the gripping member 8 while the kingpin 9 is being coupled is shown in lines l-l; the kingpin 9 can freely project into the bottom of the gap 16 in which case it, in accordance with the figures, at its upper part matches the shape of the bottom of the gap of the table plate 5, and at its

web 10 and flange 17 the bottom of the gap of the gripping member 8. After this, with the rotary pin 14 supported in the holes 13, the gripping member 8 is rotated, whereby the shaped bottom of the gap of the gripping member 8 turns from its original position and closes the bottom of the gap 16 and locks the kingpin 9 therein. This position of the gap of the gripping member 8 is shown in lines II - II and the position of the bottom of the gap is shown in a dotted lined in the Figure. When turning downwardly, the shaped upper part of the gripping member 8 at an appropriate height rests on the upward facing surface of the flange 17 of the kingpin 9 and through the kingpin 9 pulls the device 11 against the table plate 5 and thereby against the turntable 1 according to the invention. Present standards set tight tolerances for the mounting of the kingpins 9, e.g. their vertical position is determined with an accuracy of 1.5 mm. This enables, through appropriately selected threadings of the bushing 7 and gripping member 8, a preferred rotation for locking of the gripping member 8 to be 180 to 270 degrees. If the pitch of the thread is e.g. 10 mm, a reliable and traction causing locking is produced with tolerances of about 3.5 to 6 mm. The gripping member 8 need not necessarily be tubular in accordance with Fig. 1 but may be threaded merely at its lower part with only the upper part shaped so as to incorporate a gap and a gripping surface, with appropriate tolerances. The rotation of the gripping member 8 can be arranged, instead of the above described method using the rotary pin 14, in many other known ways, among others by means of a chain and a motor, or through various known lever-type solutions. In Fig. 1 is with a dotted line indicated a motor 18 with supporting structures used in chain drive; in this version a chain gear has been connected to the lower part of the gripping member. The tube 4 may be provided with more than one apertures 15, through one of which is arranged to take place the rotation of the gripping member 8 to one direction and from another aperture the rotation to the other direction. This kind of situation with for example two apertures would be appropriate where the use of pulling by cable, a lever mechanism and an hydraulic cylinder is preferred. The sliding bearings 3 also permit the rotation of the tube 4 relative to the tubular body. This is convenient because the pulling of the device 11 at the kingpin 9 against the turntable 1 would in cases involving turning cause wear in the kingpin 9 and the gripping member 8. In any case it is to be stated that the invention has above been described with reference to a few advantageous embodiments only, however, not wanting to restrict the application of the invention to these embodiments only, several modifications being possible within the scope of

the inventive idea as defined by the following claims.