The present invention relates to a device for supporting a trailer, such as a house trailer, comprising raisable and lowerable support legs, which are placed at the corners of the trailer, a mechanism for raising and lowering said sup- port legs, and drive means for activating said mechanism.

It is previously known, for example, in house trailers, that raisable and lowerable legs are mounted at the corners of the house trailer in order to compensate for uneven ground when the trailer is parked at a camp site, for example, so that the floor of the trailer will be essentially horisontal . In such a device, it is necessary to adjust each leg individual¬ ly, and this, in addition to taking considerable time, also makes it complicated to get the house trailer into a horizon- tal position, i.e. so that the floor will be substantially horizontal. It can also be difficult to gain access for adjustment of each leg, when the trailer is parked close to an object, such as a wall, a hedge or the like.

The purpose of the present invention is to achieve a device of the type described by way of introduction, by means of which it is possible to simply and quickly support the trailer. The design of the same is also simple.

This is achieved according to the invention by virtue of the fact that it has the characterizing features as disclosed in independent claims 1 and 3.

Preferred embodiments of the invention have the features dis- closed in the subclaims.

The invention will be described in more detail below with reference to the accompanying drawings, which show preferred embodiments.

Fig. 1 shows a side view of a house trailer, having a device according to the invention.

Fig. 2 shows a perspective view of the device mounted on a frame of a trailer, such as a house trailer, and with support legs which are pivotable in vertical planes longitudinal to the frame.

Fig. 3 shows a plan view of the device mounted on a frame of a trailer, such as a house trailer, and with support legs which are pivotable to an angle out from the frame as well. the frame.

Fig. 4 shows a partial, partially cut-away view of the device .

Fig. 5 is a view from below of a preferred alternative of the device according to the invention.

Fig. 6 is a side view of the drive unit in Fig. 5.

Fig. 1 shows a device 1 according to the invention for sup¬ porting a house trailer 2. The device is provided with for¬ ward and rear support legs 3 and 4, which can be raised and lowered and which are placed at the corners 5 and 6 of the house trailer. A mechanism 7 and 8, respectively, will be described in more detail below and is intended to raise or lower the respective support legs. A crank 9 with a hook 10 is intended to be hooked into an eye on an input shaft 11, which is connected to a differential transmission 12, which is in turn coupled to the two support legs 3 and 4. Fig. 1 only shows the support legs on the right-hand side of the house trailer, but it is of course obvious that the device according to the invention can also comprise a similar diffe¬ rential transmission arranged for raising and lowering the support legs at the remaining two corners of the house trailer.

Fig. 2 shows a frame 101 at the ends of which support legs 102, 103, 104 and 105 are pivotally mounted. The support legs are pivotally mounted at their upper ends, and a link 106,

107, 108 and 109 is pivot? ^" .y joined at one end to its indi¬ vidual support leg, and at its other end, via a nut thereon, is adjustably connected to a threaded rod 110 and 111 (shown only on one side of the frame in Fig. 2) . These threaded rods are solidly joined t shafts 110' and 111' , which are in turn connected to the different transmissions 112 and 113. An in¬ put shaft 114 extends from the box of the differential trans¬ mission 113 and through the box of the differential transmis¬ sion 112, extending out at 115 where an eye is arranged. A crank 116 has a hook 117 at its end which is intended to be engaged with the eye on the shaft end 115. The shaft 114 is journalled so that it can be displaced longitudinally to three different positions, a first position where it only engages the differential transmission 113, a second position where it only engages the differential transmission 112, and a third position in which it is disengaged. The engagement between the shaft 114 and the differential transmissions 112 and 113 can be effected in another manner; for example, by means of gear clutches (not shown) , where gears on the shaft 114 are arranged to be displaced axially to alternative engagement with the pinion gears of the differential trans¬ missions.

The mechanism for each support leg 102-105 can be provided with an input shaft with an eye 118,119 for manual adjustment of each leg individually. It will sometimes be necessary to form a fine after-adjustment of one or more support legs.

Fig. 3 shows a frame 201 for a two-wheeled trailer. A device 202 according to the invention is arranged thereon with two differential transmissions 203 and 204. The support legs 205, 206, 207 and 208 are all pivotable out a certain angle a transversely to the frame in accordance with the known art. The shafts 209, 210, 211 and 212 from the differential trans- missions 203 and 204 actuate the mechanisms for the support legs 205, 206, 207 and 208 to raise and lower them.

Fig. 4 shows differential transmissions 301 and 302 in a device 303 according to the invention. The device 303 has

drive means comprising an input shaft 304 which, through axial displacement, can be coupled via a first or a second transmission clutch 305 or 306 to the pinion gear 307 of one of the differential transmissions 301 or 302. Even though only one 302 of the differential transmissions is shown in cut-away view, it will be understood that the transmission 301 will have the same components. A transmission has a differential drive gear 308 and gears 311 and 312, respec¬ tively, joined to shafts 309 and 310, respectively. A crank 313 with a hook 314 is intended to engage an eye 315 on the input shaft 304. As can be seen in Fig. 4, displacement of the input shaft axially can either drive the differential transmission 301 or the differential transmission 302 or place the shaft 304 in a disengaged position. The input shaft 304 is arranged to activate only one of the differential transmissions at a time.

When parking a trailer, such as a house trailer, the eleva¬ tion of the front portion of the trailer is first adjusted by means of the support wheel at the trailer hitch. The differ¬ ential transmissions are then activated one at a time to make the floor of the trailer level. It makes no difference if the trailer is parked on uneven ground since the differential transmissions will automatically compensate so that each support leg will be in firm contact with the ground.

It should be pointed out that the differential transmission shown in Fig. 4 is only an example, and therefore each known differential could replace that shown. The clutch 305,306 can also assume another form. It is also possible to replace the crank with a motor, or arrange a motor for each differential, or a crank for each differential.

In order to achieve the same direction of rotation of the shafts connecting the support leg mechanisms to the differen¬ tial transmissions, these should be provided with a reversing transmission.

Fig. 5 shows from below a preferred alternative embodiment

of the device accorαing to the invention, in which the manual mechanical crank mechanism shown in Figs. 1-4 has been re¬ placed by electric motors. Each differential 401,402 is coupled to an electric motor 403 and 404, respectively, which via a reducing gear 405 and 406, respectively, and a pinion gear 407 and 408, respectively, drives a crown gear 409 and 410, respectively, of the differential 401 and 402, respec¬ tively. From each differential 401,402, there extends - as in the previous embodiments described - two drive shafts 411,412 or 413,414 in opposite directions to a front or rear retract¬ able support leg 415,416 or 417,418. In this embodiment, the support legs on the respective longitudinal sides of the trailer can be regulated separately, in a manner similar to that described above, but more comfortably without requiring a crank and the transverse transmission shaft 114,304 with the clutches 305,306, as described in the preceding embodi¬ ments .

As is shown in more detail in Fig. 6, a gear train 420 is coupled to a differential 401 (or 402) to drive the shafts 411,412 (or 413,414) in opposite rotational directions so that the support legs will move in the same direction when the same type of screw mechanism is used at the support legs .

Even though the device according to the invention has been described with reference to the embodiments shown in the drawings, it can be modified within the scope of the follow¬ ing patent claims.