GB2244257A - A jack for levelling a wheeled vehicle - Google Patents

Abstract

A wheeled vehicle, especially a trailer caravan, is levelled by first adjusting its level fore and aft and then adjusting its level transversely by means of a jack (10) which is fitted around the wheel (12) of the caravan while the wheel is still on the ground. The jack comprises a frame e.g. (14) which can be fitted around the wheel and which is then raised by a jacking screw (32) so as to raise the vehicle, through the wheel, to enable the support legs of the vehicle to be adjusted before the wheel is lowered again to the ground. The jacking screw (32) is carried by a cross member (26) which fits removably into the end of a cradle (15) of the frame. The frame can alternatively comprise spaced angle arms (52, Fig. 6 not shown), a round frame (Fig. 9, not shown), or a socket-like arrangement (Fig. 7, not shown). <IMAGE>

Description

A JACK FOR LEVELLING A WHEELED VEHICLE This invention relates to jacks for the side to side levelling of a wheeled vehicle. Although applicable to any wheeled vehicle, the invention is especially useful in connection with trailers, for example trailer caravans. The term "caravan" will be used in this specification to mean a trailer caravan unless otherwise indicated.

Caravans normally have either one pair of road wheels on a single axle mounted centrally below the body of the vehicle, or two pairs of road wheels on a pair of axles which are close to each other and about halfway along he vehicle. When the caravan is not attached to a towing vehicle, it is supported (when at rest but not in use) simply by its road wheels and by a small jockey wheel at the front end - The jockey wheel is typically carried by a post, mounted in the A-frame of the caravan which carries the coupling element that is attachable to the towbar of a towing vehicle.The jockey wheel post is vertically retractable when not in use, and when it is in use the vertical position of the jockey wheel can usually be adjusted so that the caravan is level in the fore-and-aft sense, but it cannot be used to give transverse (side to side) levelling.

To provide the additional stability required when the caravan is parked and in use (i.e. when people are inside it or entering or leaving), a retractable leg or "steady" is commonly mounted below each corner of the body of the vehicle. These are adjustable for height, and it is the four corner steadies that, once correctly adjusted so that all four are in contact with the ground, carry the weight of the stationary vehicle in use The steadies also give rigid support, bearing in mind that the road wheels are mounted to the vehicle body through an appropriate resilient suspension.

In use, the caravan must be level, both longitudinally and transversely. It is quite easy to correct its level in either one of these senses alone, by adjusting the corner steadies; but the need to provide levelling in both directions at the same time calls for an adjusting process on all four steadies which can be both tiresome and time consuming.

Jacks of various kinds for raising the body of a vehicle from the ground are known. One type of jack is the hydraulic or screw type jack which has a vertically movable post on which the body cr chassis of the vehicle is supported. Another type is the lever jack, in which one end of a lever supports the body at a suitable point on the latter, the lever being supported on the ground through the jack frame or body. The jack.

is so constructed that operation of the lever lifts the part of the vehicle body in engagement with it. Some types of trailer also have jacks permanently fitted: these usually serve, with the road wheels, to support th trailer when parked, in the same way as the corner steadies or legs of a trailer caravan.

Ramps and other levelling devices are also known for use in levelling caravans: these have the disadvantage that the vehicle has either to be driven on to. or manually manoeuvred so as to put the road wheel concerned in position c'n, the levelling device.

An object of the invention is to provide a simple means whereby a wheeled vehicle can be levelled quickly and reliably.

Another object is to provide a means whereby the vehicle can be levelled first in one direction (e.g.

longitudinally) and then in the other direction (e.g.

transversely), without the need to rely on adjustment of corner steadies or the like to set the vehicle body in its correct level attitude.

According to the invention, a jack is provided for levelling a vehicle transversely, the jack comprising a vehicle support means, actuating means for raising and lowering the vehicle support means with respect to the ground, and a primary ground support element for supporting the actuating means on the ground, wherein the vehicle support means is a support frame having at least one wheel support surface defining at least two wheel support points spaced apart for supporting a wheel of the vehicle, the support frame being adapted to be brought into supporting engagement with a component of the wheel while the wheel rests on the ground.

Th vehicle, typically a caravan, is levelled when supported by its road wheels and jockey wheel, by first using its corner legs or integral jacks to obtain foreand-aft levelling, and then using the levelling jack according to the invention to bring the vehicle body into its correct attitude by tilting it transversely until the body is level from side to side. This is done by fitting the jack to the road wheel on the lower side, raising that wheel by an appropriate amount, lowering the corner legs on the same side until they support the vehicle, and then lowering the wheel to the ground by releasing the jack.

Preferably, the support frame comprises side elements having said support surfaces, secondary ground support means at one end of the side elements for supporting the latter on the ground, and a first transverse element carried by the actuating means and spacing the side elements apart at their other end.

According to an important, preferred feature of the invention the support frame further includes at least one cross bar mounted across the frame between its side elements to engage the wheel.

Jacks according to the invention may take a wide variety of different forms. For instance, the support frame may be suspended or cantilevered from a vertically movable element of the actuating means, without the support frame being itself supported on the ground when in use: thus, here, the jack has no secondary ground support means.

The frame may be A-shaped, comprising firstly a pair of arms pivoted together at one end to the said vertically movable element and divergent away from the latter, with an outwardly projecting support element carried by the free lower end of each arm to define the said wheel support surfaces, and secondly, a tensioning member, adjustable to vary the distance between the support elements and carried by the arms.

Alternatively, the support frame may comprise a Ushaped member open at the top to allow a component of the wheel to be supported therein.

It should be noted that the particular component of the wheel which is actually engaged by the jack may be its tyre, or any other suitable component, for example a drum which may be secured coaxially with the road wheel itself for the specific purpose of being engaged by the levelling jack.

The support frame may be in the form of a clamp. In one form of such a jack, the frame comprises a pair of arms defining the said wheel support surfaces and carried at one of their ends by the said vertically movable element through first securing means, the arms being arranged to be secured together at their other end by second securing means, at least one of the said securing means being releasable to allow the arms to be separated so as to enable the frame to be fitted around the said wheel component.

Basically, the jack according to the invention consists of a simple structure which can be inserted under an appropriate part of the wheel while the vehicle is stationary and fully supported by its wheels. It is not necessary to attach the jack to the wheel or to any other part of the vehicle.

In the case of a vehicle not having support legs or steadies, or on-board jacks, once it has been levelled from side to side using the jack, it can be blocked up.

The levelling jack can be removed after blocking the wheels, or left in position for additional support. In the former case the jack can therefore be made of relatively lightweight construction, since it is not required to support the weight of the vehicle when the vehicle is under applied loads, for example during occupation of a caravan, or during loading and unloading operations.

Various embodiments of the invention will now be described, by way of example only and with reference to the accompanying drawings, in which: Figure 1 shows a first embodiment of the jack according to the invention; Figure 2 is a side elevation showing the jack of Figure 1 in use; Figure 3 shows a second embodiment; Figure 4 is a perspective view showing the jack of Figure 3 in use; Figure 5 is a side elevation showing a third embodiment of the jack in use; Figure 6 shows the jack of Figure 5; Figure 7 is a general view of a fourth embodiment of the jack; Figure 8 shows an attachment for a caravan wheel for use with the jack of Figures 7 and 9; Figure 9 shows a fifth embodiment of the jack; Figure 10 shows the components of the jack of Figure 9; Figure 11 shows a modified version of the jack of Figure 1; and Figure 12 in similar to Figure 2 but with the jack of Figure 11.

Figures 1 and 2 show a jack 10 for levelling a caravan from side to side, i.e. in the vertical plane containing the common transverse axis of its two road wheels, one of which is seen at 12 in Figure 2. The jack comprises a vehicle support means 14 and actuating means 16, for raising and lowering the support means 14 with respect to the ground.

The support means 14 is in the form of a support frame comprising a generally U-shaped cradle 15 and a cross bar 26. The cradle 15 comprises two parallel side elements 18 joined by a transverse foot element 20 at one end of the side elements 18. The other ends of the latter are free, to define between them an access opening 22 which provides a passage for a component of the wheel 12 (in this case the tyre) to enable the frame 14 to be brought into a wheel supporting.position while the wheel rests on the ground.

The free end of each side element 18 carries a semicylindrical socket 24 to accommodate the respective ends of the cross bar 26. The elements 18 and 20 are formed by bending a simple metal bar or tube, across which a support bar 28 is welded. The actuating means 16, carrying the cross bar 26 and supported by a foot 30 constituting a primary ground support element for supporting the actuating means 16 on the ground, consist of a simple jacking screw 32 terminating in the foot 30 and engaging through a threaded hole in the cross bar 26. The foot element 20, here a simple, straight tubular stretcher, provides a secondary ground support means for supporting the cradle 15, and therefore its side elements 18, on the ground when the jack is in use.

The cylindrical outer surfaces of the side elements 18 of the cradle 15 act as vehicle support surfaces, each defining at least one wheel support point, i.e a point (or a line or zone) engaged by the tyre, as seen in Figure 2, so that the wheel has at least two-point support.

With the caravan stationary and supported by its two road wheels 12 and its jockey wheel (not shown) in the usual way, the cradle 15 is manoeuvred around whichever one of the wheels 12 is at a lower level than the other, with the wheel passing through the opening 22 until the support bar 28 rests against the back of the wheel as seen in Figure 2. The cross bar 26 is inserted in the sockets 24, the foot 30 is placed on the ground, and the screw 32 is operated to raise the bar 26. This causes the cradle 15 to tilt upwards about the line of contact between the foot element 20 and the ground, this line thus being a fulcrum.

It will be observed that the side elements 18 of the frame engage the outside of the tyre of the wheel 12, below its centre line; as the cross bar 26 is raised using the screw 32, the frame 14 thus lifts the wheel and therefore the whole side of the caravan. When both sides of the caravan are at the same level, its corner jacking legs or corner steadies, not shown, can be operated in the usual manner to give any required levelling front to back, i.e. in the longitudinal plane, so that the levelled caravan is then supported by all four of its corner legs. In raising the wheel 12, the jack 10 will first have compressed the associated suspension spring of the caravan. The screw 32 can now be turned in the reverse direction to release he jack, so that the cross bar 26 can be released rom the cradle 15, which is then removed.

It will be .oted that, while the wheel is being raised, the foot element 20 of the frame remains on the ground, the load being taken by the two side elements 18 and the support bai 28. It is important also to note that the cross bar 2E prevents the cradle 15 from slipping with respect to t e wheel 12 under the influence of the various forces exe ted during the lifting operation.

Figure 3 is an explo ed view of another form of the levelling jack. Here the vehicle support frame 14 comprises two tubular -shaped members 36, each including one half of t ' foot element 2O, these two halves being spigoted tother and easily separable from each other. An inter lediate cross bar 38 also consists of two halves, spi oted together and being part of the respective membe. s 36, while at the end of the frame opposite the foot e ment 20, further transverse portions are spigot to a cross bar 26 carrying the screw 32, with its root 30, as before. As shown in Figure 4, this jack is i assembled together in situ around the wheel 12, so that he members 36, separated from each other, define a "passage" for the tyre, to enable the frame to be brought into its wheelsupporting position while the wheel i. on the ground.

Once the frame is assembled around the vre, the latter is supported at one side on the support Lr 38. At its other side, the tyre rests on a rod 40, which is inserted through holes 37 in two plates 39 welded to the side portions of the members 36. Sever holes 37 are provided in each cf these plates, so that the position of the bar 40 can be adjusted to suit tyres of different sizes. The bar 40 is secured by a wing nut 42.

Operation of the jack of Figure 3 is as before, with the foot element 20 and the foot 30 both resting on the ground. However, as can be seen in Figure 4, the side elements 36 here lie generally in planes parallel to the side of the vehicle instead of being transverse as in Figure 2. It should be noted that the frame 14 of Figure 3 can be configured, by suitable choice of dimensions, so as to be used with the side elements 36 in the same orientation as the side elements 18 in Figure 2, if desired.

The foot element 20 in Figure 3 may be modified by shortening the two end portions of the members 36 so that they do not meet, but instead define a gap between them, through which the frame can be manoeuvred around the tyre. In that case the frame does not need to be assembled after being placed around the tyre, but can be preassembled; accordingly the frame may be made as a single unit, though it should be noted that the cross bar 26 should be rotatable about its own axis in the members 36.

In Figures 5 and 6, the frame, 50, of the jack is suspended from a vertically movable element 56 of the actuating means 16. The frame 50 comprises two plates 52, pivoted together at one end to a horseshoe bracket 54 carrying the element 56, which is a threaded block 56 in which the jacking screw 32 is engaged. Each plate 52 carries at its other end a wheel support bar 58 projecting laterally outwardly on the side opposite to the screw 32. On the same side as the bar 58, each plate 52 has a boss 60 projecting laterally from the plate and pivoted to it. A tension bolt 62 is passed through holes 64 in the bosses 60, and secured by a wing nut 66.

With the bolt 62 and wing nut 66 removed, the jack is placed adjacent to the wheel 12. The frame plates 52 are then manoeuvred into position so that the bars 58 come into contact with the running surface of the tyre, the latter entering the space or opening 69 defined between the plates 52 and a pair of retaining plates 68. The plates 68 are carried by the free ends of the bars 58. To facilitate this operation, the screw 32 may be adjusted with respect to the block 56. The bolt 62 is then inserted through the bosses 60, and the wing nut 66 tightened until the frame 50 becomes a rigid "A" frame engaging the tyre at two points, as seen in Figure 5. The frame 50 is then raised using the screw 32, so as to raise the wheel as before.

The jack shown in Figure 7 has a frame consisting of a vertically disposed, U-shaped plate 70 carried on and cantilevered from the bracket 54 through a bracket extension portion 74. The bracket 54 is carried on the screw 32 as in Figure 6. The plate 70 is open at the top, and is designed to support from below the cylindrical surface 71 of a wheel component in the form of a flanged drum 72. The drum 72 is attached to the wheel, not shown, by means of the wheel nuts, the studs for which are inserted through holes 76 in the drum 72.

The drum 72 may remain on the wheel during normal use and running of the caravan.

In the form of the levelling jack shown in Figures 9 and 10, the frame, 88, again consists of two members hinged together, generally as in Figures 5 and 6.

These consist of two arms 90, seen in elevation in Figure 10(a). Figure 10 (b) is a view as seen from the right hand side of Figure 10 (a). In this case the frame acts as a clamp. The arms 90 are freely hinged together at one end, through a securing means comprising a pivot pin 92, while at their other end they have flanges 94 which are releasably bolted, by further securing means comprising a bolt 95 and wing nut 36, direct to the threaded block 56 carried on the adjusting screw 32. Using the drum 72 of Figure 8, the arms 90 are opened out to define an opening through which the flange 73 of the drum 72 can pass, and are then closed up against the surface 71 and bolted to the block 56, thus clamping the jack to the drum 72. The jack can then be operated to raise the wheel.

It should be noted that, although in Figures 9 and 10 the frame 88 is, in effect, suspended from the block 56, it may if desired be cantilevered sideways. In any embodiment of the invention in which the wheel support means is in the form of a clamp, it is of course not necessary that its wheel support surfaces are orientated so as to support the wheel generally from below.

Referring now to Figures 11 and 12, the levelling jack 10' shown therein differs from that of Figures 1 and 2 in only the following respects. The cross bar 26 is cranked as indicated at 100, to allow the screw 32 to extend past it without the need to weaken the latter by providing a threaded hole to engage the screw 32. The cross bar 26 is instead carried, through a web 104, by a travelling block 108 which has a threaded. hole engaging the screw 32. The ends of the bar 26 carry upstanding locating pins 101, which engage in holes 102 in the sockets 24 (these pins and holes may of course also be provided in the jack of Figure 1). The side elements 18 of the cradle 15 are cranked slightly: this illustrates the fact that the cradle may be made of any convenient shape. Finally, the foot element 20 is pivoted in a base plate 206, which may if necessary be supported on a wooden block or plank (not shown), especially if the ground is soft. The base plate 106 may of course also be provided in the jack of Figure 1.

It will also be appreciated that an additional, removable cross bar, arranged for example in a similar way to the bar 40 in Figures 3 and 4, may be added to the cradle 15 of Figure 1 or Figure 11. Such a removable bar cooperates with the cross bar 28 to trap the wheel 12 against relative movement along the frame 14.

Claims (16)

1. A Jack for levelling a vehicle trallsvets*ly, comprising a vehicle support means, actuating means for raising and lowering the vehicle support means with respect to the ground, and a primary ground support element for supporting the actuating means on the ground, wherein the vehicle support means is a support frame having at least one wheel support surface defining at least two wheel support points spaced apart for supporting a wheel of the vehicle, the support frame being adapted to be brought into supporting engagement with a component of the wheel while the wheel rests on the ground.

2. A jack according to Claim 1, wherein the support frame comprises side elements having said support surfaces, secondary ground support means at one end of the side elements for supporting the latter on tEle ground, and a first transverse element carried by the actuating means and spacing the side elements apart at their other end.

3. A jack according to Claim 2, wherein the side elements define between them at their said other end a passage for insertion of the wheel, the first transverse element being a separate member from the side elements, and the side elements having means for removably receiving the first transverse element.

4. A jack according to Claim 3, wherein the secondary ground support means is a transverse stretcher joining the side elements of the support frame.

5. A jack according to Claim 3 or Claim 4, wherein the means for receiving the first transverse member comprises a socket carried by each side element.

6. A jack according to any one of Claims 2 to 5, wherein the support frame further includes at least one cross bar mounted across the frame between its side elements to engage the wheel.

7. A jack according to Claim 6, wherein a said cross bar is mounted removably in the support frame.

8. A jack according to Claim 6 or Claim 7, wherein the support frame is configured so that its side elements extend transversely of the vehicle in use, to be supported on the ground at the said one end behind the wheel, with a said cross bar supporting the wheel from behind in a plane orthogonal to the wheel axis:

9. A jack according to Claim 1, wherein the frame is suspended or cantilevered from a vertically movable element of the actuating means.

10. A jack according to Claim 9, wherein the frame is A-shaped, comprising firstly a pair of arms pivoted together at one end to the said vertically movable element and divergent away from the latter, with an outwardly projecting support element carried by the free lower end of each arm to define the said wheel support surfaces, and secondly, a tensioning member, adjustable to vary the distance between the support elements and carried by the arms.

11. A jack according to Claim 10, including retaining elements carried by the support elements for retaining the wheel between the retaining elements and the arms.

12. A jack according to Claim 9, wherein the frame comprises a U-shaped member open at the top to allow a component of the wheel to be supported therein.

13. A jack according to Claim 1 or Claim 9, wherein the support frame is in the form of a clamp.

14. A jack according to Claim 13, wherein the frame comprises a pair of arms defining the said wheel support surfaces and carried at one of their ends by the said vertically movable element through first securing means, the arms being arranged to be secured together at their other end by second securing means, at least one of the said securing means being releasable to allow the arms to be separated so as to enable the frame to be fitted around the said wheel component.

15. A jack according to Claim 14, wherein one of the securing means is a pivot.

16. A jack for levelling a vehicle transversely, constructed, arranged and adapted to operate substantially as described in the foregoing description with reference to Figures 1 and 2, or Figures 3 and 4, or Figures 5 and 6, or Figures 7 and 8, or Figures 8 to 10, or Figures 11 and 12, of the drawings of this Application.