EP0809600A2

EP0809600A2 - Load-bearing vehicle

Info

Publication number: EP0809600A2
Application number: EP96903841A
Authority: EP
Inventors: Francois Xavier Carton De Tournai
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-02-16
Filing date: 1996-02-16
Publication date: 1997-12-03
Anticipated expiration: 2016-02-16
Also published as: DE69605284D1; WO1996026153A2; BE1009110A4; ES2142048T3; DE69605284T2; WO1996026153A3; ATE186899T1; EP0809600B1; AU4780196A

Abstract

A load-bearing vehicle such as a fork-lift truck (1) capable of loading itself automatically from the ground onto a raised surface. The truck includes a front leg (2) and a back leg (3) both of which have ground-engaging roller means (13, 14, 16) and are telescopic relative to a rigid frame (4) including a load-bearing surface. Automatic loading is performed by lowering the telescopic base portions (8, 9, 10, 11) of the legs (2, 3) one after the other or simultaneously depending on whether the vehicle has one or two lifting means, then shifting the weight of the vehicle onto the ends of the projecting member such as a prong (5) provided with a roller (7, 77). The front leg (2) is raised, the frame is moved forward onto the raised surface then the back leg (3) is raised to enable the truck to move about freely on said raised surface.

Description

- 1 -

Load trolley

The invention relates to a load carriage movable, ⁵ and versatile self-loading a horizontal level lower than an upper horizontal level and vice versa.

Self-loading forklift type handling devices are already known. French patent ¹⁰ 1,506,606 discloses the general principle applied.

It is most often a forklift, the fork being guided along a mast. Once the load placed on the tray level or higher, for example ⁵ the loading surface of a truck, the fork resting on said surface can serve as a fulcrum to raise the chassis (or frame) of the carriage, it being understood that at least one foot at the rear of the chassis forming a rear stand is sliding and serves as a complementary support point ⁰ when the chassis is raised. The end of the forks includes a rolling means allowing, once the chassis is raised, the advancement of the machine on the upper level then the raising of the rear stand. Handling The machine is thus "AUTOLOAD" on the higher level ⁵ and can move freely about it.

Different application variants are known in particular from documents FR 2317217, WO83 / 04226, DE 3508194, FR 1252876, US 4061237 DE 2630774, US 5217342.

To the knowledge of the applicant, none of the devices proposed in the literature is used. - 2 -

One of the main drawbacks of self-loading vehicles of the prior art consists in that:

- in the case of a rising fork and stabilizing feet located inside the fork, during the lifting operation of the chassis, the stabilizing feet at the base of the mast tend to lose parallelism with the fork which prevents their housing between or in it on the upper level, housing which is essential to be able to advance the load and the chassis on the upper level before raising the rear stand,

- in all cases the forks lose their parallelism with the ground, the end of the fork tine resting on the fulcrum tends to lift. The front stand tends to move backwards and therefore can lower the heel of the fork to a height lower than that of the support point, which prevents the advancement of the assembly on the level superior.

The pressure exerted on the forks changes during the self-loading operation; when lifting the load the pressure on the forks, at its connection to the mast, exerts a torque from top to bottom. On the other hand after having placed the loaded forks on the upper level and when the chassis is raised with the stabilizing foot, the load and the weight of the chassis are located between the ends of the forks and the rear stand (s) and the torque s 'exercises from bottom to top. In the first position the forks are below the horizontal and in the second position above the horizontal. The telescoping foot being hung and weighted on the front tilts and the end of the stabilizing foot is below the horizontal if some play is possible.

This play is important with the machines of the prior art because the distance between the rollers of the same raceway of the fork in the mast is small because conditioned by the acceptable height of the mast above the upper loading level.

Furthermore, when the load rises, it is in point of support on the ground on the front wheels of the machine. When the chassis rises, it and the load are supported on the end of the forks which are placed on the upper level, which means that the distance between the support points has considerably increased and that the number of points of friction, which can create play, has also increased.

Indeed at the point of friction of the fork carriage on the mast is added the point of friction of the sliding part of the rear telescopic stand. Each friction point constitutes an obstacle to the rigidity of the assembly and therefore worsens the play at the end of the forks.

Other disadvantages appear on examining the documents of the prior art. For example, there must be several active lifting means with an oblique rear stand -4 -

(PCT publication WO83 / 04226), or else self-loading cannot be done at all intermediate heights (patent application FR 7521967).

The invention therefore aims inter alia to provide a light and economical forklift which does not have the aforementioned disadvantages.

The invention aims in particular to ensure the parallelism of the stabilizing feet on the one hand and of the elements forming a fork on the other hand so that these feet can be housed at the same level and between or in said elements, said feet supporting a load and based on a level higher than that of the rear wheels. This upper level is for example the loading platform of a truck, a quay or a simple step. However, it is at a height equal to or less than the height of the chassis, but may be higher if, for example, multiple telescoping hydraulic cylinders are provided.

According to one aspect of the invention, this parallelism effect is obtained by proposing a forklift whose forks are integrated into the chassis, the latter therefore being integral with the vertical movement of the forks during the entire self-loading operation or d 'self-unloading. A front stand, preferably telescopic, is therefore provided in one or more vertical housings, or stand heads, provided integrated into the chassis. A stand, in the context of the invention, may include one or more telescoping feet. Of preferably the front stand is composed of two telescoping feet on either side of the front part of the chassis, said feet being made integral by one or more horizontal crosspieces, eg lower or upper, and possibly including feet (arms) of horizontal stabilization, most often directed, for a forklift, forward. The stand also comprises, on one of the aforementioned crosspieces, one or more elements of a lifting means, for example a jack, the complementary element forming part of the chassis.

Generally, the load support means is therefore integrated into the chassis. This makes it possible, on the one hand, to ensure perfect rigidity between the rear and front parts of the chassis and this support, and a minimum of play between the front sliding feet, with the stabilizing foot, and the vertical elements receiving these feet. The minimum clearance is obtained by providing a maximum distance between the support rollers of the telescoping foot in the retracted position in the corresponding vertical element of the rigid frame (head), and the rollers of this vertical element which return inside. of the telescoping leg. This maximum difference between the different sets of rollers constitutes a lever balancing arm of the fork.

The aforementioned self-loading principle comprising a load support integrated into the chassis can be advantageously applied to handling equipment other than forklifts. The load can possibly be on a load support provided for above or on the sides of the chassis. The fork is then replaced by an element projecting from the support points of the chassis, element preferably comprising at least one rolling means.

The fact of having a chassis which telescopes itself upwards at the same time as the load, increases the total height of the device and allows, in the low position, to have a rear stand leg which can almost completely enter the stand integrated into the chassis, excluding the wheel and wheel support, and which can gradually come out as the chassis is raised to its maximum point by one or more lifting means.

Furthermore, this principle, unlike the prior art represented by document WO 83/04226, makes it possible to provide only an active lifting means, eg a jack.

This allows efficient self-loading in any position and allows the device to be moved safely by leaning on the wheels of the rear stand when the latter is partially extended from the stand head. This principle of upward telescoping allows self-loading at covered levels, that is to say with which is associated a reduced operating height in height.

The rear stand may optionally include a second lifting means. The invention therefore relates to a device for handling loads or accessories comprising at least:

- a rigid upper chassis fitted with at least two crutch heads, including a front head and a rear head; one or more load support elements or accessories integrated into or rigidly connected to said chassis; - at least two crutches associated with said crutch heads and capable of sliding one relative to the other, extending downward, and the lower ends of which are provided with at least three rolling means which can take support on a horizontal level; - At least one element of said chassis, or rigidly integral with said chassis, projecting from the surface determined by the projection of the support points of the crutches, this projecting element being provided, preferably at its end, with '' at least one rolling means and being arranged so as to be able to bear on a level slightly lower than the upper extreme level of the front stand, in contact with the ground (the overlap of the stand head and the stand being maximum) - the projection of the center of gravity of the machine being located in the surface defined by the projection of one or more support points of the projecting element and of the support point (s) of the rear stand, c ' is to say opposite to and most distant from this projecting element relative to said chassis; lifting and blocking means provided for lowering at least the front stand, and / or raising and blocking independently on the one hand the front stand and on the other hand the rear stand, the most distant from the protruding element .

According to a preferred embodiment, in particular when there is only one lifting means, at the base of the front stand there is provided at least one stabilizing foot directed towards the outside or inside, provided with its end of a rolling means in contact with the horizontal level.

The stabilizing foot is directed inward if the projection of the center of gravity of the assembly, with the support element possibly loaded, is inside the surface delimited by the support points of the crutches on the ground . If this projection is outside, the most frequent case for a forklift, the feet will be directed outwards in the direction of this projection in order to ensure the stability of the assembly, that is to say so that the projection of the center of gravity is between the rolling means of the front stand and the stabilizing foot. According to a variant of the invention, the stabilizing feet can be orientable relative to the telescoping feet which support them.

According to a preferred variant of the invention, the load support element is the element projecting from the surface determined by the support points of the crutches. According to a preferred embodiment, the load support element is in the form of a fork and the machine then consists of a forklift.

Preferably, the crutches and the crutches heads comprise telescopic profiles, eg U-shaped angles or hollow tubes of square or rectangular cross section. Crutch heads can completely cover the top of crutches, or crutch feet. In practice, the covering extends to the rolling means or to cross members possibly provided between a pair, front or rear, of stand legs. Also preferably, a crutch slides by telescoping inside a crutch head.

According to a preferred aspect of the invention, the feet of the front stand sliding in corresponding stand heads by means of two sets of rollers or equivalent sliding or rolling means, one of the games being integral with and located at the base of the crutch head and the other set being located at the upper end of the stand leg, the distance between the two sets being at least when the foot is fully lowered and maximum when the foot is fully raised. In this latter position, which is particularly crucial for bringing the stabilizing feet to the same level and parallel to the fork tines, the play at the end of the fork tines is reduced as much as possible thanks to the leverage effect. This arrangement can be adopted in the context of the invention because the load support is secured to the chassis, the lever arm can then be housed in the chassis in the high position. For self-loading trolleys with fixed mast, the lever arm should be added to the useful height of the mast and the overall height therefore becomes greater compared to the machine applying the principle of the invention and cannot self-load in spaces with reduced height.

For loading in a covered truck, the overall height is obviously important. This results in an important advantage of the device according to the invention.

According to a particular embodiment of the invention, the set of rollers of the crutch head consists of two superposed rollers with a diameter slightly less than the internal dimension of the crutches, but slightly offset on either side of the vertical axis median of the face of the crutch head receiving their axes, so that by the effect of the residual play the raceways on the movable crutch are located on two opposite internal faces thereof.

According to one embodiment, it is provided that a set of rollers fixed to the tops of the front telescoping feet sliding in the head which constitutes a vertical element of the chassis carrying the fork, is associated with a device making it possible to adjust the spacing of the rollers in view to make up for any play. In the case where the load support is not projecting from the chassis, and / or in the case where the projection of the center of gravity of the assembly is not between the points of support of the element protruding and front crutches, one or more additional rolling means may be provided, integral with the chassis, slightly anterior to the rear crutches, and being arranged so as to be able to bear on a level slightly lower than the lower extreme level of the rear stand fully retracted into the telescoping heads.

The rolling means are wheels, castors or fixed or pivoting rollers. Preferably the rolling means of the foot (s) of the rear stand are swivel wheels.

In the case for example of a forklift, which constitutes a preferred form of the invention, in order to be able to easily handle for example pallets or loads of this kind, the rolling means, in this case the rollers, constituting the support points located at the free end of the projecting element, namely the fork, comprise means arranged to move these rolling means substantially vertically so that they can occupy two extreme positions, a first position in which the rolling means are practically embedded in the thickness of the free end of the fork, and a second position in which they project relative to the underside of this free end, and in that, preferably, these displacement means comprise a device for blocking said means for immobilizing the above-mentioned rolling means at least in the two aforementioned extreme positions.

Since in many commercial vehicles the bumper is attached to the rear end of the loading platform, it is advantageous to provide sufficient space between the rolling means of the rear and front stands so as not to have to press the bumper to raise or lower the rear stand. This necessary space between the two crutches increases all the more space outside the fork of the machine.

Consequently, according to a preferred embodiment of the invention, the chassis is extendable horizontally without compromising its rigidity. This makes it possible to reduce the overall length once the vehicle has been loaded onto a vehicle. Extension is possible by providing a system of horizontal telescopic profiles equipped with fixing means such as a pinout. If the chassis can thus retract, it can lengthen and thus better adapt to longer loads if the load support is positioned on the chassis or on one or more lateral faces of the chassis.

It should be added that, for self-loading or self-unloading, sufficient space is also necessary between the end of the stabilizing feet and the front rollers of the forks, so that when the machine is in support on the rear stand on the one hand and on the rollers of the fork on the other hand, there is sufficient passage, at the level of the bumper, to let the stabilizing foot go up or down with the front stand.

The means for lowering and raising the feet can be formed by at least one double-acting cylinder. These jacks can be actuated in a known manner by a pump actuated e.g. by an electric motor powered by a battery, or a manual pump. A version of the machine according to the invention not incorporating a motor can advantageously provide a chain drive mechanism, for example a crank winch for lifting the chassis and on the other hand a hydraulic circuit with double cylinder effect and stop valve to allow movement of the rear stand (s).

In the case of using only one lifting means, the rear hydraulic stand is therefore only a load holding stand which is controlled by an opening or closing valve of the hydraulic line which holds or releases the hydraulic piston from its position depending on whether the valve is open or closed. Thanks to this system, any sudden fall of the stand is avoided and blocking in any place is possible. A means of stabilizing the front stand, eg in the form of two horizontal legs already mentioned, is required if there is only one lifting means. Security systems can advantageously be provided, in particular to intervene during the unloading operation.

Thus, a security system can be provided to prevent the trolley from tipping backwards during self-unloading. A locking means is provided for this purpose associated with the front stand which must move back for unloading. A counterweight wheel fixed at the end of a lever, directed towards the rear, can pivot around an axis fixed at the base of a front stand leg. This wheel rolls at floor level, that is to say at the same level as the rolling means of the front stand. When the lever of the counterweight wheel pivots because of the difference in level, it releases a blocking shoe which was kept in the inactive high position by said lever. The front stand has not yet left the upper level. The shoe is wedged between the vehicle and this upper level, eg a truck floor, due to the rearward pull of the carriage. The shoe brake system lifts the vehicle until said pivoting lever meets a stop. The operator can then reassemble the assembly by lowering the rolling means of the projecting element, with concomitant lowering of the rear stand. Furthermore, when the lift truck and the load are on the vehicle and the rear stand is resting on the ground, the forks can be hidden by the load from the operator's eyes. During an unloading maneuver, if the assembly is moved too far back, the maneuver can be abruptly interrupted by the tilting of the assembly towards the front.

Consequently, according to yet another aspect of the invention, compatible with those previously described, a system is provided for blocking the rolling means of the protruding element, when the rear stands are in the lowered position and the front stands are position raised, said blocking means becomes active when the rolling means of the projecting element approaches beyond a predetermined threshold of the edge of the upper level.

It can be, as more fully illustrated in the appended figures, an additional wheel less distant towards the outside than the rolling means, but fixed at the end of a lever in free pivoting at a point of the element projecting further outward than the rolling means. When this wheel falls into a vacuum, during an unloading operation, it causes the pivoting of the lever which is provided with a braking means or blocking of the rolling means. If the latter is a wheel, the locking system may use a concentric ratchet wheel, of smaller diameter and juxtaposed with the caster, which will be locked in the direction of rotation. suitable by a lug on said lever. An eccentric swivel lever braking system can also be applied.

According to the invention, it is therefore possible to adapt not only a conventional visual sight gauge which makes it possible to control the position at which it is necessary to stop, but in the event of operator distraction, a system for blocking the front roller. of the forks described above makes it possible to avoid inadvertent tilting.

According to another embodiment, each of the feet which form the rear and / or front crutches are connected to the chassis while being able to be independent with respect to each other. Each leg then has its own hydraulic cylinder, part of a single stand. They can be ordered simultaneously. This is possible because it is easy to lift a load at at least two points at the same speed when the hydraulic cylinders are vertical.

The invention thus allows a so-called "high" rolling system in which the chassis is slightly raised, the possible load constituted by a pallet being isolated from the ground. The rolling is then carried out on the wheels of the rear legs, or the front legs if the position of the center of gravity allows, and on the rollers of the fork which will be lowered and locked in the support position. When the fork element is reassembled, integral with the chassis, the rolling system of the telescopic leg (s) (front) remains on the ground and allows the rollers of the fork, locked in the low position, to rise to the level and land there without the pallet or fork itself touching this level. We can then push the whole further on the second level.

When a pallet is docked and it has to be picked up, the fork and the stabilizing foot must be introduced below the pallet, the rear stand then resting on the ground. To lift the pallet, you must both forcefully lower the end roller of the forks and the rear stand to lift the whole machine, including the pallet.

The invention has been described with reference to forks as equipment of the machine. It is obvious that the embodiments described can be adapted to other types of load support.

In its compact arrangement, the rear wheels can be arranged so as to be able to be placed between the wheels of the front legs in order to reduce the overall dimensions as much as possible, the operation being carried out by telescopic contraction of the horizontal elements of the chassis.

Detailed description of an embodiment The invention will be better understood on reading the following description with reference to the accompanying drawings, description and drawings provided by way of non-limiting examples only.

The numbering used in the different figures is identical for functionally analogous elements.

Fig. 1 shows in perspective a schematic embodiment of the machine according to the invention, which is a forklift truck, crutches raised and therefore chassis and integrated fork lowered.

Fig. 2 shows in perspective the same machine with the crutches lowered and therefore the chassis raised.

Fig. 3 illustrates in more detail the roller system which guides the telescoping leg in the corresponding telescoping head.

Fig. 4 illustrates in more detail a means of adjusting the rollers located at the upper end of the telescoping feet.

Fig. 5 illustrates an example of attachment of the fork tines and the stabilizing feet.

Fig. 6 illustrates a system for lowering and raising the rollers provided at the free end of the teeth of the fork. Fig. 7 illustrates an anti-dislodging system provided at the end of the teeth.

Fig. 8 illustrates a variant of the system of FIG. 7.

Fig. 9 illustrates another security system associated with the chassis.

Fig. 10 illustrates a system for lowering the rollers of the fork.

Fig. it schematically shows the loading and unloading operation using a forklift according to the prior art, compared to a self-loading trolley of the invention.

Fig. 12 illustrates a self-loading operation with a pallet grip

Fig. 13 illustrates the self-loading operation with driving wheel

Fig. 14 very schematically shows a machine for transporting long loads placed on a support provided laterally to the chassis.

Fig. 15 illustrates a self-loading operation with a machine provided with a long load support

Fig. 16 illustrates self-loading in the case of a machine with stabilizing foot oriented towards the inside of the chassis. With particular reference to Figs. 1 and 2, a forklift truck 1 is illustrated comprising two crutches 2 and 3 (hidden) provided at the front and at the rear of a chassis 4. The two crutches 2 and 3 are tucked into the crutch heads 8 ', 9' and 10 ', 11' respectively. The fork 5 is integral with the rest of the chassis 4 and located at its base. The fork is however interchangeable with other forks by attachment to an element provided for this purpose. The fork 5 is composed of two teeth 6 provided at their ends with rollers 7 projecting from the underside.

Note the presence of a second roller 77 on each tooth, which is involved in the anti-dislocation system more particularly illustrated in FIG. 9

The two telescopic crutches 2 and 3 are each composed of two telescopic legs 8,9 and 10,11 respectively, which are housed in crutches heads 8 ', 9', 10 ', 11' forming part of the chassis. Each stand leg is provided at its point of support on the ground with a wheel 13, 14, 15, 16, the rear wheels 14, 15 being, in this example, pivoting.

The carriage is also provided with stabilizing feet 12 integral with the front stand which in this example are oriented towards the front and located between the teeth of the fork 5. The stabilizing feet are also provided with rollers 19, possibly pivoting. The chassis lifting system is also illustrated with respect to the front stand 2. This system comprises a winch 50 fixed on an upper cross member connecting the heads of the front stand and a chain 51 returned by a toothed wheel located on a cross member of the front stand. A crank 52 is provided projecting rearwards as well as a locking handle 53.

Also illustrated, adapted between a transverse element of the rear stand and the chassis, a double-acting cylinder 60 and the corresponding hydraulic circuit, an oil tank inside the chassis 61, a shut-off valve 62 and a two pipes 63 The circulation of the oil can be interrupted at any time by means of the valve 62, which blocks the rear stand in a determined position.

The cylinder rod 65 is mounted on the side of the chassis while the cylinder 66 is fixed to the rear stand, on a crosspiece joining the lower parts of the sliding feet.

The vertical movement of the rear stand takes place passively, either under the effect of the weight of the chassis in the case of its re-entry into the corresponding head, or under the effect of its own weight when the stand is lowered . The longitudinal members of the chassis can advantageously be provided telescopic at 70 so as to be able to vary the length of the assembly. As already mentioned, this embodiment allows the presence of a bumper projecting from the loading platform of a truck.

More incidentally, a manual brake 110 is also illustrated for the wheel 13 of the front stand; a lever 102 for lowering and raising the rollers 7 of the ends of the teeth of the fork according to a mechanism known per se (see p.e. fig. 10); a pivoting gauge 103 making it possible to determine by visual reference the position of the rollers 7 when the latter cannot be estimated because of the load. This gauge is illustrated in the folded position.

Fig. 2 represents the same machine with the two crutches lowered, that is to say the chassis 4, the fork and the possible load raised. One distinguishes there, contrary to the case of fig. 1, the stand legs 8, 9, 10 and 11.

Fig. 3 illustrates in more detail the roller system which guides the front telescoping leg 8 in the corresponding telescoping head 8 '. A pair of rollers 40 is located at the base of the telescoping head 8 ′ which is in the form of a U-shaped profile whose base face receives the axes of rotation of two superimposed rollers 40 and of diameter slightly less than the internal dimension of the profile constituting the telescoping foot. This profile is U-shaped inverted by compared to the profile of the telescoping head and of a dimension allowing the sliding inside thereof. Two opposite internal faces of this profile constitute the raceways of the rollers 40.

The telescoping foot comprises a second pair of rollers 41, in the form of rollers, at its upper end. The raceways are two opposite inner faces of the U-shaped section constituting the telescoping head 8 '.

In the figure, unlike the case of Figures 1 and 2, the cylinder cylinder is secured to the chassis.

Note that in the lowered position of the telescoping feet, the distance between the pairs of rollers is minimal. On the other hand, in the retracted position of the feet, the two pairs are separated as far as possible, which advantageously reduces the play and allows the tines of the fork to remain parallel to the stabilizing feet which must reach the same level to allow the chassis to be able to move on the second level.

Fig. 4 illustrates a detail of embodiment by a side view A and a top view B of the set of rollers 41. The distance between the rollers 41 fixed to the upper end of the profiles constituting the legs 8 and 9 of the front stand can be adjusted by a nut 61 acting via a rod 62 on an internal axis 65. parallel to the axis of the rollers, on which is mounted two pairs of connecting rods 63, 64 whose outer ends pivot each on an axis 66 coaxial and integral with the axis of the rollers 41. The angle between the connecting rods, and consequently the distance between the axes of the rollers, can thus be adjusted.

Fig. 5 illustrates in more detail an embodiment for mounting on the one hand the teeth to form the fork secured to the chassis and on the other hand the stabilizing feet secured to the front stand.

According to one embodiment, the teeth of the fork can be arranged on a horizontal cross member 170 of the chassis so that they can be moved thereon parallel to itself, in a direction parallel to the line of the support points of the rollers 7 above. The distance between the two teeth 6 can thus be adjusted as a function of the load 100 to be moved.

If, for example, the upper end 171 of the tooth 6 has the shape of an inverted U with uneven branches used to suspend the tooth 6 from the upper cross-member 170, provision may be made between the latter and the stand head 8 'of the chassis. 4 a clearance for the passage of the short branch 172 of the U which, having an appropriate length, can then slide along the face of the upper cross member turned towards the profile 8 forming the stand leg. To support the load, each tooth 6 can furthermore bear against a lower cross member 173, parallel to the upper cross member 172, of length equal to the latter and also fixed to the two heads of crutches 8 and 9 vertical.

To immobilize each tooth 6 on the chassis 4, one can provide a fixing pin 174 which can be by example inserted at the same time in a hole 175 of the tooth 6 and in one of the holes 176 provided in the upper cross member 172, in alignment with the hole 175 when the tooth 6 is in the chosen position.

According to one embodiment of the invention, the stabilizing feet 12 of the front stand 2 can be arranged according to the representation at the bottom of FIG. 5. In this case the front stand 2 comprises a horizontal cross member 180 of rectangular hollow section, cross member of connection between the two legs of crutch 8 and 9. Two parallel faces of this horizontal crossbar are laid horizontally and have a width greater than the dimension, taken in the same direction, of the crutches heads. After fixing the legs of the crutches on the cross member 180 so that their longitudinal axes intersect that of said horizontal cross member 180, the latter retains on its upper face 181 two free longitudinal edges 182. In addition the horizontal cross member 180 can extend in door on the outside of the legs of crutches 8 and 9. For their part, the two stabilizing feet 12 aforesaid of the front crutch each have at their end 183 opposite their free end, on their upper face 184, two claws 185 opposite which are aligned along the longitudinal axis of the stabilizing foot 12 and which extend upwards from the upper face 184. These claws 185 fixed on the stabilizing foot 12 so that, when the latter has its upper face 184 applied against the horizontal inner face of the cross member 180; they enclose between them, by parallel vertical internal faces, the vertical faces 186 of this crosspiece 180. D * e plus claws 185 close on the upper face 181 of the cross member 180, each time extending horizontally, and transversely to the cross member 59, only over part of the respective free longitudinal edge 182. Sufficient play is maintained between, on the one hand, the cross member 180 and, on the other hand, the foot 12 and the claws 182 to allow this foot 12 to slide along the cross member 180, between the legs of the crutches and also beyond, outside of these if the cross member 180 is extended overhang. To immobilize a foot 12 on the cross-member 180 in a chosen position, a locking pin 187 can be inserted into a horizontal hole 188 of a claw 185 at the same time as into one of the horizontal holes 189 which can be brought into alignment with the hole 188 and which are provided in the corresponding vertical face of the cross member 180.

It can be seen in FIG. 5 that, in the mounting example proposed for the teeth 6 and for the stabilizing feet 12 of the front stand, the teeth 6 can be arranged between these stabilizing feet 12. It could also, according to other arrangements, place them outside of them or by covering them, depending for example on the dimensions of pallets or loads 100 to transport, lift etc.

Fig. 6 illustrates a system for lowering and raising the rollers provided at the free end of the teeth. The support rollers 7 of each tooth 6 of the fork, may each comprise means, such as a double arm 120 supporting the shaft of the caster, on either side of the latter.

The double arm 120 can be arranged to move this support point 129 of the caster 7 substantially vertically so that it can occupy different positions, for example by pivoting around a horizontal shaft 122 which is fixed in the tooth 6 formed by a horizontal tube 132, the underside 133 of which has been hollowed out. In a first extreme low position, the support points 129 are mostly embedded in the thickness of the free end, while being able to roll. In a second extreme high position, the support points 129 protrude relative to the lower face 133 of this free end. A hydraulic cylinder system or the like makes it possible to maintain each roller 7 in the desired position.

The first extreme position mentioned above is arranged and used to be able to introduce the fork tine 6 into a usual pallet. The second extreme position mentioned above is used for example when bringing with the machine a pallet loaded on the upper plate and the roller 7 must keep the pallet away from the plate during the steps of raising and translating the 'machine on the platform to allow easy movement of the machine and the pallet during these stages. Fig. 7 illustrates a system for blocking the rollers when the ends of the teeth 6 of the fork, during the operation of removing the carriage after self-unloading, approach the edge of the upper level beyond a certain limit. The load and the fork are supported on the roller (s) 7 rolling on the upper level and located at the end of an arm 120 capable of lowering or lifting the roller by pivoting around the shaft 122 (see also fig. 6).

When the carriage is withdrawn, the roller 77 mounted in free rotation at the end of a lever itself pivoting about an axis parallel 78 to the axis of rotation 79 of the rollers 7, is no longer supported by the upper level, and under the effect of gravity, it falls from a certain distance and drives the lever comprising a brake 76 which comes to block the caster 7 by peripheral jamming therewith. This results from the fact that in reverse the wheel drives the brake downwards and that the distance between the brake and its axis of rotation is less than the diameter of the wheel. When the wheel turns in the opposite direction it pushes on the brake which lifts and allows the wheel to come off.

Immobilization can also be done by introducing a lug into a ratchet wheel coaxial with the roller shaft and juxtaposed therewith.

Fig. 8 illustrates an improved version of the roller locking system 7, in the low position and, partially illustrated, in the high position. In the system described above, the lever supporting the braking system is more or less inclined according to the high or low position of the rollers 7. To have invariable braking in the two positions, the fastening of the braking system is fixed parallel to the fastening of the roller so that when the roller goes down, the roller contacts the lever always at the place where the brake element is located, because the inclination relative to the ground of the lever supporting the counterweight wheel remains identical.

According to this aspect of the invention, the support of the roller shaft 7 is a bent element 120 pivotally fixed at 122 to the fork 6. The element 71 supporting the wheel 77 is pivotally fixed at 78 on an element 85 itself in pivoting on the fork at 86. The position of the axle support 86 is chosen so as to be in the center of a circle b passing through the point 78 in the low position and the point 78 in the high position. In this way the relative position of the lever 71 and the wheel 77 relative to the roller 7 is identical in the extreme positions. The passage from one position to the other is effected by a pull on the rod or the cable 80 which causes the rotation (circles a, a ') of the elbow element 120, and of the roller 7 supported there, around the axis 122. This roller braking system acts almost equally in all of the intermediate positions that the roller 7 may have relative to the fork 6.

Fig. 9 illustrates a system for blocking the carriage intended to prevent it from falling when it is pulled towards the rear of the platform of a vehicle or any other equivalent situation. A previous amount (foot of stand 9) with a counterweight wheel 90 at the end of a lever 91 is pivotally attached to this upright. A braking system is retained in the inactive high position by lever 91. This lever indeed retains a bar or ergo 92 perpendicular to a lever 94 provided with a blocking shoe 93 provided at its lower end. The lever 94 is provided pivotally attached to a projecting element 95. The counterweight wheel rolls on the ground, in the case illustrated at the upper level. When withdrawing from a higher level to a lower level, the wheel 90 falls due to the difference in level, the blocking shoe 93 is released, falls by gravity and blocks the machine by wedge effect. If the removal is continued, the lever 94 associated therewith raises the chassis until it comes into contact with the stop element 96. At this stage, the machine being blocked can be released by lowering the rollers end of the fork with concomitant lowering of the rear stand.

Fig. 10 very schematically illustrates an example of a system for lowering the rollers at the end of the fork. The arm 80 acts on the element 120 to rotate it around the shaft 122 fixed to the fork 6, from a low position to a high position and vice versa. The arm 80 is controlled by the vertical cylinder 82 via the deflection element 81, the assembly being located at the front of the chassis 4. The cylinder is actuated by the electro-hydraulic group via a distributor (not shown).

It will be noted that the fact that the chassis of the machine according to the invention incorporates the fork facilitates the integration of a lifting system based on the descent of the rollers located at the end of the forks. In stackers of the prior art, the forks are independent and slide in slides and must therefore contain the means of descent of the rollers. According to the invention, all the lifting means can be incorporated at the level of the chassis.

Fig. It schematically illustrates the different stages of the self-loading operation on the platform of a truck for a forklift according to two embodiments of the prior art on the one hand (steps 1 to 5 of fig 11a, principle of document WO83 / 04226 Lutz or US 5,217,342; and FR 1,506,606, fig.11 b), and according to the invention on the other hand (steps 1 to 5 'fig. 11C). The platform is at an N2 level relative to the NI level of the ground.

According to fig. 11a, the fork of the prior art moves on a fixed mast 200 relative to the frame or chassis (steps 1-2), to rise to a height slightly greater than that of the upper level N2. The fork is then engaged above this level by advancing the carriage and then the fork, provided at its end with rolling means, is lowered to bear on the upper level N2. The frame is then raised and the rear stand lowered in the same step 3. After further advancement of the carriage in 4, the rear stand is raised in 5 from level Ni to level N2 and the carriage can move to this higher level, self-loading being finished. It will be noted here that two active lifting means acting simultaneously are necessary, on the one hand to lift the load support (1 in 2) and on the other hand to lower the rear stand (2 in 3) by lifting the chassis .

According to fig. llb representative of the prior art according to documents FR 2317217 and FR 1506606, the fork carriage is directly connected with the support of the rear stand. The fork-guide link and fork and rear stand connections are not very rigid. The motorization of the rear stand lifting system does not allow the machine to pass from a level below 0 to a level x of low height. The machine cannot be transferred to each of the intermediate levels between the maximum authorized level, which is not the case for the machine according to the invention.

According to the invention (fig. Lie), the steps are analogous except that the fork is secured to the frame and the assembly is therefore lifted by the front stand in 2 '. The rear stand can descend under its own weight depending on the rise of the chassis. After putting the fork down and blocking the rear crutch, the front crutch is then raised and, in step 3 ', the crutch retracted into its crutch head maintains by lever effect thanks to the double play of the rollers the foot stabilizer parallel to the horizontal fork. The stabilizing foot will not strike the edge of the loading level as is possibly the case in 3. Indeed under the effect of the weight, the angle alpha in 3, according to the prior art, can be less than 180 °, which is avoided in 3 'thanks to the fact that the front crutch is retracted into the crutch head which is rigidly secured to the frame, that is to say also to the fork.

It will be noted that according to this principle, only one lifting means is required, that is to say that making it possible to lift the chassis with the load support.

The principle of the integral chassis-fork makes it possible, as in the prior art of FIG. HA, to connect, thanks to the chassis, the front lifting means and the rear stand support; and as in the prior art of FIG. 11B to connect the rear stand support directly to the fork.

The invention combines the advantages of each of the systems of the prior art, without suffering the disadvantages. Thus, although the principle of the prior art of FIG. 14A is used, a single lifting means is sufficient for self-loading.

In both cases the unloading operation is carried out by following the above-mentioned steps in reverse.

Fig. 12 illustrates an operation for picking up a pallet 69 at the quay. The chassis is brought to the high position (first means of lifting the load). In order to be able to completely insert the fork 6 under the pallet 69, the stabilizing foot 12 must first be brought back up to the fork 6 (step c), which allows the advancement of the machine. towards the platform. The roller descent mechanism 7 (step e, second lifting means) concomitant with an additional descent of the same amplitude from the rear stand (3rd lifting means) makes it possible to lift the pallet 69. The machine can then self-load as illustrated above or can go back to lower the front stand, then the chassis with the fork loaded with the pallet.

Fig. 13 is a simplified diagram illustrating the self-loading operation with a motorized rear wheel train. To move from c to d, the driving wheels (14,15) of the rear stand are blocked then, eg by the action of a hydraulic cylinder acting on the horizontal beams 70, the amount 9 ′ is removed from the amount 10 ′ (crutch heads). The upright 9 'is thus pushed forward. We can then reassemble the rear stand 10, release the drive wheels, lock the front wheels (12,13) and bring the two uprights to their original distance. The motorized rear axle is then able to move the elevator to the upper level.

We show in fact, seen from the front (A) with a load 100 on both sides, and in perspective (B) a machine for transporting long loads placed on an integrated support

99 provided laterally to the chassis body 4. In the case illustrated, the load 100 can for example be made up of plates, panes or window frames. As for the other figures, the numbering of the elements makes it possible to recognize their functionality by comparing them with the corresponding elements of the corresponding figures.

Fig. 15 schematically illustrates the loading operations on the platform of a truck of a machine according to the invention which is, in this embodiment, a load carriage distributed over the entire chassis. It will be noted that in this case, an additional rolling means III, integral with the chassis, may be necessary to maintain the stability of the assembly when the rear stand is raised. In fact, the projection onto a horizontal plane of the center of gravity G of the chassis and load assembly must always be inside the surface defined by the projection of the bearing means in abutment. This additional rolling means III will be located at the base of the chassis between the rolling means of the two crutches, preferably just before the rear crutch. It will be noted that the safety systems described above can be applied, more precisely behind the wheel 7 (see discussion of FIGS. 7 and 8) at the level of the chassis, and behind the wheel 16 at the level of the front stand (see discussion of FIG. . 9). Fig. 16 illustrates an embodiment in which stabilizing feet 12 are provided towards the rear, ie towards the chassis. This case can arise when the center of gravity is between the rolling means of the two crutches.

The present invention is not limited to the concrete embodiments set out above, various modifications that can be made without departing from the scope of the invention, and any new element, taken individually or in combination, forming part of it.

Claims

1. Equipment for handling loads or accessories comprising at least:

- a rigid upper frame (4) provided with at least two crutch heads, including a front head (8,9 ') and a rear head (10', 11 ') one or more load support elements or accessories integrated into said chassis (4) or rigidly attached thereto;

- crutches (2,3) associated with said crutch heads and capable of at least partially sliding relative to said crutch heads, extending downward and the lower ends of which are provided with at least three rolling means (13, 14, 15, 16) can be supported on a horizontal level;

- at least one element (5) of said chassis (4), or rigidly integral with said chassis (4), projecting relative to the surface determined by the projection of the support points of the crutches, this projecting element ( 5) being provided with at least one rolling means (7) forming a fulcrum and being arranged so as to be able to bear at a level slightly lower than the upper extreme level of the front stand (2);

- The projection of the center of gravity of the machine being located in the surface defined by the projection of the support point (s) (7) of the projecting element and the support point (s) (14,15) of the rear stand (3), that is to say opposite to this element projecting relative to said chassis (4); lifting (50,51,52) and blocking means provided for lowering at least the front stand (2), and independently raising and blocking on the one hand the front stand (2) and on the other hand the rear stand ( 3), the most distant from the projecting element (5).

2. Machine according to claim l wherein the load support element (5) is or is directly rigidly secured to the protruding element (5) relative to the surface determined by the support points of the crutches (2 , 3).

3. Machine according to claim 2 wherein the load support member is in the form of a fork (6).

4. Machine according to any one of the preceding claims, in which there is provided at the base of the front stand (2) at least one stabilizing foot (12) directed outwards or inwards, provided at its end with a rolling means (19) in contact with the horizontal level.

5. Machine according to any one of the preceding claims, in which one or more feet (8, 9, 10, 11) of the front stand slide in the corresponding stand heads by means of two sets of rollers (40,41 ) or equivalent means, one of the games (40) being integral and located at the base of the crutch head (8 ', 9', 10 ', 11') and the other game (41) being located at the end greater than the ^'distance (8,9,10,11) of the stand, The distance between the two games being minimum when the foot is completely lowered and maximum when the foot is fully raised.

6. Machine according to any one of the preceding claims, in which the legs (8 to 11) of the crutch and the heads of the crutches (8 'to 11') are telescopic profiles, U-shaped angles or hollow tubes of square cross section or rectangular

7. Machine according to any one of the preceding claims, in which the set of rollers (40) of the crutch head consists of two superimposed rollers with a diameter slightly less than the internal dimension of the crutches, but slightly offset on either side. of the median vertical axis of the face of the crutch head receiving their shafts, so that by the effect of the clearance the raceways on the movable crutch foot are located on two opposite internal faces thereof .

8. Machine according to any one of the preceding claims, in which one or more additional rolling means (III) are provided, integral with the chassis, slightly anterior to the rear crutches, and being arranged so as to be able to bear on a level slightly lower than the lower extreme level of the rear stands fully retracted into their telescopic heads.

9. Machine according to any one of the preceding claims, in which at least one of the rolling means is a swivel wheel (14, 15).

10. Machine according to any one of the preceding claims, in which the rigid frame (4) is extendable horizontally by adjustment of horizontal telescopic elements (70).

11. Machine according to any one of the preceding claims, in which the means for lowering and raising the feet consists of at least one double-acting cylinder (60) or a chain winch (50).

12. Machine according to claim 1 wherein there is provided a locking system of the rolling means (7) of the projecting element (6), when the rear stand is in the lowered position and the front stand (2) is raised position, and when the rolling means (7) of this projecting element (6) rests on a higher level and approaches below a predetermined limit of its edge.

13. Machine according to any one of the preceding claims, in which means are provided for lowering the rolling means of the projecting element, in particular so as to be able to thus lift a pallet.

14. Machine according to the preceding claim also comprising an additional lifting means for lowering the rear stand simultaneously by means of projecting rolling.

15. Machine according to any one of the preceding claims, in which the crutches are telescopic crutches.

16. Machine according to any one of the preceding claims, in which the crutch feet of said crutches slide inside or outside of the crutches heads.