FR2616201A1 - Support platform equipped with a device for stabilising in the horizontal position - Google Patents

Abstract

The present invention relates to a support platform, particularly for holding on the ground a device or equipment K having a working position or operating position which is strictly vertical, this platform 1 comprising a base structure 2 which defines a support plane and rests on ground support feet of variable height A, B, C, D, the said platform being characterised in that it comprises at least four ground support feet of variable height A, B, C, D positioned so as to define, by their connections to the base structure 2, the vertices of a parallelogram, these feet being coupled to means for adjusting their height, which are designed, in each of the diagonally opposite pairs of feet AC; BD, so as to extend over a given height one or other of the feet and simultaneously to shorten the opposite foot by the same height. Application particularly to the holding on the ground of telecommunication antennae, handling cranes, etc.

Description

Support platform equipped with a stabilization device in a horizontal position
The present invention relates to a support platform, in particular for the maintenance on the ground of a device or apparatus in a strictly vertical working or operating position, this platform comprising a basic structure which defines a support plane and rests on ground support feet of variable height.

Such platforms serve in particular, among other uses, to place on the ground telecommunication antennas which, being able to function correctly only in a perfectly vertical orientation, require that the support plane of the platform can be stabilized with precision, and repeatedly, whatever the state of the land
In current platforms of this type, the stabilization in the horizontal position of the support plane is done by an individual height adjustment of the support feet under the visual control of a horizontal indicator fixed on the platform.

 But, as is known, in the four-legged platforms, which are the most common, it is very difficult, in the context of such an adjustment, to control the pressure on the ground of each foot d 'support and it almost always happens, after stabilization that a foot is overloaded or underloaded compared to the others, which is of course detrimental for the maintenance of a perfect horizontality.

 To remedy this problem, it is therefore essential to carry out a corrective adjustment action repeated on each of the support feet. However, this corrective action, which can only be carried out by trial and error, has the drawback of prohibiting any possibility of automation of the overall process of stabilization of the platform with, moreover, a certain imprecision in the horizontality obtained. To this is added another drawback residing in the fact that the elongation force of the support legs develops in the basic structure of the platform significant torsional and bending stresses which can in the long term affect the rigidity of the latter.

The present invention proposes to remedy all these drawbacks and, to do this, it relates to a platform of the type specified in the preamble, which is characterized in that it comprises at least four feet of support on the ground of variable height, positioned so as to define, by their connections to the basic structure, the vertices of a parallelogram, these feet being coupled to means for adjusting their height, which are designed for, in each of the pairs of feet diagonally opposite, lengthen one or other of the legs to a given height and simultaneously retract the opposite leg to the same height, so as to gradually pivot the support plane around the axis defined by the fixed support legs of the other pair, in order to stabilize it in posi
horizontal tion.

 The particular positioning of the support feet on the ground of the platform according to the invention means that the connection points of two diagonally opposite feet will be permanently at the same distance from the pivot axis defined by the diagonal joining the connection points the other two feet. This construction characteristic, combined with the balanced action of the adjustment means on either side of each of the pivot axes of the support plane., Will have the consequence that the pressure on the ground of the support feet will be kept from the start. at the end of the support plane stabilization operation and that, in addition, no bending or twisting torque will be introduced into the base structure of the platform.

 It should be noted that these advantageous results are obtained without having to proceed by trial and error with corrective actions on the support feet. On the contrary, the intervention of the adjustment means, bringing the support plane in a horizontal position, is limited to two continuous and simple actions to be controlled, which correspond respectively to the pivoting operations of the support plane around the two axes defined by the two. pairs of diagonally opposite support legs. It therefore follows that it is very easy to automate the platform stabilization process according to the invention, for example by controlling the control of the adjustment means to a detector of the horizontality of the support plane of the platform, such as than an inclinometer.

 It goes without saying, however, that the adjustment means may, as a variant, be controlled manually under the visual control of a horizontality indicator such as a pendulum or a spirit level.

 Preferably, said adjustment means are selectively switchable in two auxiliary control states, in which they are capable of ensuring individual or simultaneous actuation of the different support feet on the ground, respectively in the direction of ascent and the direction of lowering.

 Furthermore, in a platform, each support leg of which comprises, as an element for modifying its height, at least one double-acting hydraulic cylinder, the adjustment means will advantageously consist of a hydraulic control circuit, the general supply duct is connected to a first chamber of the jack of one of the feet of each pair of diagonally opposite support feet, in which the jack of the second leg is, by its first chamber, connected to the general duct back from the hydraulic circuit, the second chambers of the jacks of the feet of each pair of diagonally opposite feet being interconnected by a common connection conduit which, when actuated in one direction of the jack of one of the feet, ensures in a particularly simple way the desired synchronism of actuation in the other direction of the jack of the opposite foot.

 It will also be preferable that, in each jack, the aforementioned first chamber scit the chamber of larger section placed in the high position and that the fixed body of the jack is integral with the structure debate that the platform. In this way, the hydraulic fluid will activate, with the maximum power, the first cylinder that it supplies, in the direction of an elongation of the supporting foot on the associated ground.

It will be moreover desirable, in each pair of diagonally opposite feet, to have the possibility of lengthening the foot which, according to the slope of the ground, corresponds to the lowest point of the platform and, to allow this choice, the hydraulic control circuit preferably contains switching means capable, in each pair of diagonally opposite feet, of reversing the connection of the general supply and return conduits with said first chambers of the jacks
Furthermore, in the hydraulic control circuit, the switching means are designed to selectively place said circuit in two other configurations corresponding respectively to the two aforementioned auxiliary control states which make it possible to ensure individual or simultaneous actuation of the different jacks, respectively in the direction of ascent and the direction of descent.

The possibility of simultaneous actuation in the same direction of
cylinders is necessary for example to initially lay the platform
on the ground, when it is brought by truck to the place of use of
the equipment she wears.

According to a preferred embodiment, said switching means generally comprise, in each section of the hydraulic circuit associated with a respective pair of diagonally opposite feet, two two-way hydraulic distributors and three positions,
which are, on one side, connected in parallel, by their two tracks, on the
general supply and return conduits and, on the other side, connected,
by a first channel, to the first chamber of a respective jack and, by
the second channel, to said common connection conduit of the second chambers
cylinders, with interposition of a valve common to the two distribu
teurs
Finally, according to another important characteristic of the invention, two pumps, having respectively a large and a small flow, are mounted, in parallel one on the other, in the general supply duct of the hydraulic circuit, the discharge of each of these pumps being connected, through a stop valve, to the general return conduit of this circuit.

It is thus possible to actuate the cylinders at low, medium or high speed depending on whether one or the other of the pumps or both are in service, the deactivation of these pumps being effected by opening the respective valve by which their discharge is returned to the general return pipe of the hydraulic circuit. Furthermore, thanks to the use of these two pumps, capable of being selectively switched off, it is possible to carry out a sequential cyclic control at low and medium or high speed of the jacks for, in the case of the stabilization operation of the platform, perfectly balance the variations in stroke of the cylinders and obtain the maximum precision in the desired horizontality.

A support platform, in accordance with a preferred embodiment of the present invention, will now be described in more detail, but only by way of non-limiting example with reference to the accompanying drawings in which
- Figure 7 is a perspective view of this platform
- Figure 2 is a front view on a reduced scale of the platform alone
- Figure 3 is a geometric representation in plan of the platform of Figures 1 and 2, illustrating the basic principle of the present invention; and
- Figure 4 is a diagram of the hydraulic circuit for controlling the support feet on the ground of the platform.

 The platform 1 shown in FIG. 1 comprises a basic structure 2, formed of beams 3 and crosspieces 4 and supporting a telecommunication antenna K by means of a foldable vertical arm 5.

 In a manner known per se, the basic structure 2 rests on four identical support feet on the ground A, B, C, D, fixed to two opposite lateral beams 3. Each of these feet is in fact essentially constituted by a double-acting hydraulic cylinder, whose body 6 is integral with the respective beam 3 and whose rod 7, directed downward, ends with a small base 8 with ball joint, each cylinder acting in a direction substantially perpendicular to the plane support P of the antenna K, passing through the connection points of the jacks (see FIG. 2).

 According to a main characteristic of the present invention, illustrated in Figure 3, the four cylinders A to D are positioned so as to constitute; in the support plane P, the vertices A1, B1, C1, D1, of a rectangle. We will now specify that the geometrical figure defined by the vertices of the cylinders A, B, C, D, can be any parallelogram whose rectangle is only a particular example, the only condition sought, in the context of the present invention, being simply that two diagonally opposite vertices, for example A1, C1, are located at the same distance H from the straight line joining the two other vertices, for example B1, D1.

 The platform 1 in FIG. 1, provided with the antenna K, can be loaded on a truck with its support cylinders on the ground. A-to D retracted and antenna K completely folded: Once routed thus to the chosen location, platform 1 must be able to be placed and stabilized on the ground, after lengthening and adjusting the height of its jacks, in such a way that its support plane P is perfectly horizontal to orient the antenna K, after total deployment, in its strictly vertical operational position, regardless of the slope of the terrain.

 In accordance with the present invention, this set of operations can be carried out in a simple, reliable, precise and automated manner by means of a single special hydraulic circuit 50 for controlling the actuation of the jacks A, B, C, D , which will now be described with reference to FIG. 4.

 As can be seen, this hydraulic control circuit firstly comprises two rotary pumps 10, 11 connected by their suction to a reservoir of hydraulic fluid 12. One of these pumps 10 has a high flow rate while the second pump 11 has a low flow rate five to ten times lower than that of the first. The discharge conduits 13, 14 of the two pumps 10, 11 meet, each downstream of a non-return valve 15, 16, to form the general supply conduit 17 of the jacks. Each of these discharge conduits 13, 14 is further connected in bypass, by means of a respective stop valve 18, 19 (or one-way distributor), to the general return conduit 20 of the circuit, which closes the latter on the reservoir 12 through a filter 21. A pressure relief valve 22 is further mounted between the conduits 14 and 20.

 As shown in FIG. 4-, each of the four double-acting cylinders A, B, C, D is associated with a respective hydraulic distributor with three positions 23A, 23B, 23C or 23D, the two paths of which are of one side respectively connected to the general supply duct 17 and to the general return duct 20. On the other side, a first channel of each distributor is connected to the upper chamber 24, in this case the large section chamber, of the jack corresponding, by a first conduit 25 on which are inserted, in series and in this order from the distributor, a flow regulator 26 and a controlled valve 27. Furthermore, the lower chambers 28, in this case the chambers of small section , of the two AC or BD cylinders of each pair of diagonally opposite cylinders, are connected to each other by a common conduit 29a or 29b provided with two flow regulators 30 between which the common conduit is connected, via a respective stop valve 31a, 31b (or distr one-way ibutor) to the second channel of the two three-position distributors 23A, 23C, respectively 23B, 23D, associated with the two respective cylinders A, C or B, D, this connection being embodied by the common conduit 32 in FIG. 4 .

The above-mentioned flow regulators 26, 30, which are all of an identical design, are in fact pressure-compensated unidirectional flow regulators which, in the direction of admission into the upper or lower chamber of the jacks, make it possible to regulate the hydraulic fluid flow, whatever the pressure necessary to actuate the cylinder, and which, in the opposite direction, let the hydraulic fluid drain freely. As for the piloted valves 27, they allow in one direction, to freely pass the hydraulic fluid admitted into the upper chambers 24 of the jacks and, in the other direction, their opening is controlled by the pressure of the hydraulic fluid admitted into the lower chambers28, as symbolized by the dashed lines 33
The control of the installation on the ground and the stabilization in horizontal position of the platform 1, using the circuit which has just been described, is done as follows.

 The platform 1, provided with its antenna K, being placed on the platform of a truck, with its four cylinders completely retracted, the four distributors 23A to 23D are placed in their first control position (reference -I in the figure 4) and maintaining the two valves 31a, 31b in their rest position or free passage shown in Figure 4.Thus, the cylinders A, B, C, D, which are all four connected, d on the one hand, to the general supply conduit 17 through their upper chamber 24 and, on the other hand, to the general return conduit 20 through their lower chamber 28, can be actuated simultaneously in the direction of elongation or descent , at high, medium or low speed respectively depending on whether the two pumps 10, 11, or only one of them 10 or the other 11 of them are connected to the supply duct 17, by closing the two valves 18, 19 or valve 19 alone or valve 18 only.

 Once the four jacks have been extended enough to place the platform 1 on the ground and raise it above the truck, the latter is immobilized by bringing all the distributors back to the rest position. We can then, after moving the truck away, proceed with the platform stabilization operation.

To do this, we start by identifying in each pair of cylinders
AC or BD, that of the cylinders which corresponds to the lowest point of the platform
shape with respect to the horizontal. If it is for example, for the pair AC, of the cylinder A, the associated distributor 23A is then placed in its first control position I and the valve 31a in its controlled stop position, while maintaining the other three distributors 23B to 23D and the second valve 31b in their rest position shown in Figure 4. it follows that the two cylinders B, D are held in fixed positions while the cylinder A, whose upper chamber 24 is now connected to the supply conduit 17, progressively elongates while simultaneously actuating, at the same speed but in the opposite direction, the opposite jack C, thanks to the action of the hydraulic fluid which the jack A drives back and which is conveyed in the lower chamber 28 of the cylinder C via the common conduit 29a now isolated from the general return conduit 20; the fluid discharged from the upper chamber 24 of the cylinder C also returns to this return duct through the distributor 23C.

 In this way, the support plane P of the platform 1 gradually pivots around the fixed axis defined by the two cylinders B and D and as soon as the horizontality of the axis defined by the two other cylinders A and C is reached, the actuation of the latter is interrupted by returning to the rest position of the distributor 23A and the valve 31a.

 The same operation is carried out on the second pair of jacks B, D, the jacks A, C being this time kept in a fixed position. Once this second operation has been carried out, the support plane P of the platform 1 is perfectly horizontal and the antenna K vertical.

Of course, the general operation of stabilizing the platform 1 can be carried out at low, medium or high speed, as described above, using the pumps 10 and 11. These pumps can also allow sequential control actuation of the cylinders subjected to an extension in each pair. This sequential control, which is done cyclically using the valves 18,. 19, by alternating switching on, over a short period of time each time, of one or the other of the pumps or of the low-flow pump 11 and of the two pumps in parallel or alternatively by switching on and the alternating switching off of the two pumps in parallel, makes it possible to refine the precision of the horizontality obtained at the end of each of the pivoting movements of the support plane
? of platform 1.

The hydraulic control circuit 50 can within the framework of the ope
stabilization ration, be controlled manually under visual control
a horizontality indicator. Alternatively, however, the process of
platform stabilization can be very easily automated by
slaving of the control circuit to an inclinometer for example.

It is still to be specified that, thanks to the particular positioning
cylinders A, B, C, D, described above, and with balanced actions and
opposite direction of the two cylinders of each pair, on either side of the axis
of respective pivoting, one is, during the stabilization ltoperation
of the platform, ensured that no torsional or bending stress
ntapp = aLtr ~ in the basic structure 2 of it and that the pressure at
original soil of the support legs constituted by the jacks will be preserved.

To simultaneously retract the four cylinders, especially for
replace platform 7 on the platform of a truck, we place
the four distributors 23A to 23D in their second control position
(11 in FIG. 4) and the two valves 31a and 37b are maintained in their
rest position shown, to connect the lower chambers 28 of the
cylinders at the general supply duct 17 and the upper chambers 24 at
general return duct 20.I1 is also obvious that action can be taken
ner each cylinder individually, in one direction or the other, by placing
its distributor 23A to 23D alone in the corresponding ordered position.

Although the invention has been described with reference to cylinders
hydraulic, we can use other types of
cylinders, and in particular electric cylinders associated with a circuit of
electrical control with a design equivalent to that of the hydraulic circuit
than 50 described above.

It should also be noted that the cylinders may not constitute
that the central part of the feet of the platform according to the invention, in
the case where the load to bear would impose on them too big
section.

 It goes without saying also that the exemplified use of the platform according to the invention is not limiting. This can indeed be used to keep on the ground any device or device whose operation is linked to the search for a vertical. Apart from the antennas, it may for example be handling cranes, machine tools, various site tools, etc.

Claims (9)

 1. Support platform, in particular for maintaining on the ground a device or apparatus (K) in a strictly vertical working or operating position, this platform (1) comprising a basic structure (2) which defines a support plane (P) and rests on support feet on the ground of variable height (A, B, C, D), said platform being characterized in that it comprises at least four support feet at floor of variable height (A, B, C, D), positioned so as to define, by their  connections to the basic structure (2), the vertices (A1, B1, C1, D1) of a parallelogram, these feet being coupled to means for adjusting (50) their height, which are designed to, in each of the pairs of diagonally opposite feet (AC; BD), extend over a given height one either of the feet and simultaneously retract the opposite foot to the same height.  2. Platform according to claim 1, characterized in that said adjustment means (50) are controlled by an automatic control controlled by a detector of the horizontality of the support plane of the platform.  3. Platform according to claim 1 or 2, characterized in that said adjustment means (50) are selectively switchable in two auxiliary control states, in which they are capable of ensuring individual actuation of the different support feet at ground (A, B, C, D), respectively in the direction of ascent and the direction of descent.  4. Platform according to claim 1 or 2, each support leg of which comprises, as an element for modifying its height, at least one double-acting hydraulic cylinder (A, B, C, D), characterized in that the adjustment means consist of a hydraulic control circuit (50), the general supply duct (17) of which is connected to a first chamber (24) of the jack of one of the feet of each pair of feet diagonally opposite support, in which the cylinder of the second leg is, by its first chamber, connected to the general return conduit (20) of the hydraulic circuit, the second chambers (28) of the cylinders (A, C; B, D) feet of each pair of diagonally opposite feet being interconnected by a common connecting conduit (29a; 29b).  5. Platform according to claim 4, characterized in that the hydraulic control circuit (50) contains switching means (23A to 23D, 31a, 3ib) capable, in each pair of feet diagonally op posed (Ac; BD), to reverse the connection of the general supply (17) and return (20) conduits with said first chambers (24) of the jacks (A, B, C, D).  6. Platform according to claim 5, characterized in that the switching means (23A to 23D, 31a, 31b) are further designed to selectively place said circuit (50) in two other control configurations in which it can provide individual actuation of the different cylinders (A, B, C, D), respectively in the direction of ascent and the direction of descent.  7. Platform according to claim 6, characterized in that said switching means comprise, in each section of the hydraulic circuit associated with a respective pair of diagonally opposite feet, two hydraulic distributors (23A, 23C; 23B, 23D) with two tracks and three positions, which are respectively, on one side, connected in parallel, by their two tracks, on the general supply (17) and return (20) conduits and, on the other side, connected, by a first channel, to the first chamber (24) of the corresponding cylinder (A, C; B, D) and, by the second channel, to said common connection conduit (29a; 29b) of the second chambers (28) of the cylinders, with interposition of a valve (31a; 31b) common to the two distributors.  8. Platform according to any one of claims 4 to 7, characterized in that, in each cylinder (A, B, C, D), said first chamber (24) is the chamber of greatest section placed in high position and the body (7A to 7D) of the jack is integral with the base structure (2) of the platform.  9. Platform according to any one of claims 4 to 8, characterized in that two pumps (10, 11), having respectively a large and a small flow, are mounted, in parallel one on the other, dansle conduit general supply (17) of the hydraulic circuit, the discharge (13, 14) of each of these pumps being connected, through a respective stop valve (18, 19), to the general return conduit (20) of this circuit