EP0643009A1 - System for attaching a fork lifter with at least four attaching elements, attaching support and corresponding fork lifter - Google Patents

Abstract

The invention relates to a system for attaching a fork-lift truck (12) to the rear of a carrying vehicle (10), the said carrying vehicle (10) comprising a first sheath and a second sheath (14) in which each fork (15) of the said fork-lift truck (12) can be engaged, the said carrying vehicle (10) additionally comprising at least a third and a fourth locking and centring sheath (16), and the said fork-lift truck (12) comprising at least two locks (17) which can slide so as to engage respectively in the said third and fourth sheaths (16) so that the said fork-lift truck (12) is attached to the said carrying vehicle (10) by at least four attachment elements (15, 17). Thus, the truck (12) is fastened in a simple and sound way, and the attachment and detachment manoeuvres are simplified. The invention also relates to the attachment supports (11) and fork-lift trucks (12) of such a system. <IMAGE>

Description

The field of the invention is that of forklifts, and more specifically the transport of such carts at the rear of carrier vehicles, such as trucks.

It is indeed useful, even necessary, in many applications to have a forklift to load and unload a truck. However, it is not always possible to permanently have a forklift in all places of loading and unloading (in particular when these are not known in advance ...).

We therefore thought of associating a forklift with the truck. This trolley is conventionally used for handling operations, and is fixed to the rear of the truck when the latter is moving.

In known manner, the truck is in this case equipped with two longitudinal sleeves in which are housed the forks of the forklift. By actuating these forks in the direction of descent, it is then possible to lift the carriage, so that it no longer touches the ground. Such a technique is notably disclosed in British patent documents No. 529,605 and American Patent Nos. 3,799,379.

This known solution has many drawbacks, in particular with regard to the reliability and security of the attachment and the maintenance of the carriage to the truck. These are only ensured by the hydraulic mechanism of the forklift. A leak in this mechanism may result in a progressive lowering of the carriage, until it touches the ground. A larger breakdown can also cause the truck to fall directly. In any case, this can have serious consequences, especially when the truck is moving.

More generally, the movements and jolts due to the movement of the truck, sometimes over several hundred kilometers, cause progressive movements of the truck, which can on the one hand disturb the driving of the truck, and on the other hand, again cause the fall of the carriage.

To overcome this drawback, additional fixing devices are generally provided (chains, slings, etc.). However, these devices prove to be very insufficient.

We have also imagined equipping the truck with a removable support surface on which the forklift comes to rest. According to this technique, described in particular in the French patent document n ° 76 01424, the carriage is firstly mounted above the level of the removable support, in the same way as above. Then, the removable support is deployed under the carriage. Finally, the forklift is lowered so that it rests on the support. To ensure blocking, the carriage is pressed down, by lifting the forks.

This technique offers greater security than the techniques previously described. However, it has many drawbacks. First, it requires an operator to stand under the truck and / or under the cart to maneuver the support surface. This operation is awkward (space is limited and not very accessible), difficult (especially when the system begins to age, it is clogged by the thousands of kilometers traveled by the truck and it is more or less deformed by the weight of the carriage), and dangerous (the operator having to maneuver under the carriage while the latter is only held by his forks).

Furthermore, it remains insufficient to maintain the carriage, especially if it has faults in its hydraulic system. Indeed, if the hydraulic pressure decreases, the carriage is only carried by the removable support. This carriage will then move, and possibly fall.

In addition, the positioning of the carriage on the support surface is never very precise. Indeed, the lateral position of the forks relative to the carriage is variable, and there is nothing to control the centering. This can introduce overhangs, which damage the carriage and / or support, and which can disrupt the driving of the truck.

Another drawback of this system is that it occupies an important place under the truck, when it is in the folded position. Conventionally, the support surface must measure at least one meter to sufficiently support the cart. It therefore occupies a large volume under the truck, of the order of one meter long by one meter wide and a height of 50 centimeters. Some trucks cannot receive such equipment. Others require complex and costly adaptations.

Finally, the assembly and disassembly operations of the carriage at the rear of the truck are not easy, especially when the user is alone. Indeed, it must first engage the forks of the carriage in the sleeves provided for this purpose, then lift the carriage by actuating the forks. Then, it must descend from the carriage (operation made not easy because the carriage is raised by several tens of centimeters from its usual height), then manually maneuver the support surface (with the drawbacks already mentioned). Finally, it must go back on the carriage again to control its removal on the support.

The invention particularly aims to overcome these various drawbacks of the state of the art.

More specifically, a first objective of the invention is to provide a system for hooking a forklift to the rear of a carrier vehicle which is safe and reliable, even when the hydraulic mechanism of the forklift has failures.

In particular, an object of the invention is to provide such a system which sufficiently maintains the carriage in the transport position without using hydraulic energy. In other words, the invention aims to eliminate any risk of loss of the carriage during the movement of the carrier vehicle.

Another objective of the invention is to provide such a system, which ensures precise and systematic positioning of the lift truck, so as in particular to avoid any risk of overhang, of lateral overtaking of the truck with respect to the vehicle. ..

The invention also aims to provide such a system greatly limiting the size under the carrier vehicle, thus facilitating its installation and allowing its use with a large number of types of vehicles.

An essential objective of the invention is also to provide such a system offering great job security. In particular, the invention aims to prevent the operator from having to access under the vehicle and / or under the carriage.

Another object of the invention is also to provide such a system which is particularly simple, quick and safe to handle. In particular, an objective of the invention is to provide, in a preferred embodiment, such a system which does not require the operator to move the carriage during the hooking and unhooking operations.

These objectives, as well as others which will appear subsequently, are achieved according to the invention using a system for attaching a forklift to the rear of a carrier vehicle, said carrier vehicle comprising first and second sleeves in which each fork of said forklift is capable of coming to engage, said carrier vehicle comprising at least a third and a fourth locking and centering sleeves, and said forklift comprising at least two latches capable of slide to engage respectively in said third and fourth sleeves, so that said forklift is hooked to said carrier vehicle by at least four hooking elements.

In other words, the forklift is secured to the vehicle by at least four male elements (the two forks and the two locks) which are engaged in fixed complementary female elements of the vehicle.

This is a completely new approach for those skilled in the art. The carriage is not held by a movable external element, such as a support surface. On the contrary, it includes internally all the movable attachment elements, which makes it possible to facilitate and secure this attachment.

In addition, this new solution ensures perfect lateral centering of the trolley. Indeed, the engagement of the locks is only possible in the precise position provided during the design of the system.

In addition, the latches once engaged ensure perfect lateral and vertical immobilization.

Preferably, said third and fourth sleeves form an angle with said first and second sleeves between 3 ° and 30 °.

Thus, when the locks are engaged, the carriage is securely attached to the vehicle. It cannot come off accidentally, even in the event of a hydraulic problem. It is in fact understood that the angle between the sheaths of the forks and those of the latches prevents any longitudinal movement of the carriage.

Advantageously, said forklift further comprises at least one first substantially vertical guide and locking element, and said carrier vehicle comprises at least one second complementary guiding and locking element, said first guiding and locking element engaging in said second guide and locking element when said forklift, the forks of which are engaged in said first and second sleeves, is actuated upwards.

These pairs of guide and locking elements, generally two in number, allow the operator to easily position the latches opposite the third and fourth sleeves. In addition, they cooperate in the safety of attachment, by further strengthening the lateral and longitudinal immobilization of the carriage.

Advantageously, said first and second guide elements respectively comprise a male cone and a complementary female cone.

According to a first preferred embodiment of the invention, said latches are moved hydraulically, using the hydraulic energy available on said forklift.

This solution is particularly advantageous, because it avoids any manual manipulation and allows the operator to carry out all the operations of hooking or unhooking without leaving the seat of the carriage.

According to a second embodiment of the invention, said locks are moved manually. They are for example actuated from the rear of the carriage. It is therefore not necessary to bend under the vehicle or under the trolley.

Advantageously, the system comprises at least one position sensor delivering at least end of travel information for said latches.

Thus, the operator knows precisely that the operation is finished.

The invention also relates to the attachment cradles of a system as described above, intended to be fixed to a carrier vehicle.

Preferably, such a cradle comprises unlockable fixing means, so that it can be detached from said carrier vehicle.

The invention also relates to forklifts of such a system, comprising at least two latches capable of coming to engage respectively in said third and fourth sleeves.

• la figure 1 représente un camion équipé d'un berceau d'accrochage selon l'invention d'une part, et un chariot élévateur équipé des moyens d'accrochage de l'invention d'autre part, en vue de côté;
• la figure 2 représente le camion et le chariot élévateur de la figure 1, lorsque le chariot est accroché au camion, toujours en vue de côté;
• la figure 3 présente le berceau d'accrochage de la figure 1, en perspective;
• la figure 4 présente les moyens d'accrochage du chariot élévateur de la figure 1, en perspective;
• les figures 5A à 5C illustrent les étapes successives de l'accrochage d'un chariot tel que représenté en figure 2.

Other characteristics and advantages of the invention will appear on reading the following description of a preferred embodiment of the invention, given by way of illustration and not limitation, and the appended drawings, in which:

• Figure 1 shows a truck equipped with an attachment cradle according to the invention on the one hand, and a forklift equipped with attachment means of the invention on the other hand, in side view;
• 2 shows the truck and the forklift of Figure 1, when the cart is hooked to the truck, still in side view;
• Figure 3 shows the attachment cradle of Figure 1, in perspective;
• Figure 4 shows the hooking means of the forklift of Figure 1, in perspective;
• FIGS. 5A to 5C illustrate the successive stages of the attachment of a carriage as shown in FIG. 2.

As illustrated in Figures 1 and 2, a truck 10 is equipped according to the invention with a cradle 11 intended to allow the attachment of the forklift 12, for its transport (Figure 2).

This cradle 11 is fixed to the chassis or to the plate 13 of the truck 10, in a fixed or removable manner. In the latter case, the cradle is advantageously of the type described in French patent n ° 90 14865 in the name of the same applicant as the present application. The cradle 11 includes two sleeves 14 (only one being shown) provided to receive the forks 15 of the carriage 12. It also comprises, according to an essential characteristic of the invention, two complementary sleeves 16 provided for each receiving a lock 17 fitted to the carriage 12.

When the carriage 12 is in the transport position, as illustrated in FIG. 2, the latches 17 are engaged in the sleeves 16. Thus, the carriage 12 is hooked to the truck 10 by four separate points (the two forks 15 and the two locks 17).

In order to prevent the carriage 12 accidentally detaching from the cradle 11, the sleeves 16 are slightly inclined downward, looking from the rear towards the front of the truck 10. Thus, the sleeves 14 and 16 are not parallel but form an angle for example between 3 ° and 30 °. The carriage 12 cannot therefore be separated from the cradle 11 without the latches 17 being removed.

Note in Figure 1 that the size of the cradle 11 is very limited. In practice, its length L is of the order of 50 cm, which allows it to be installed on most chassis or truck platforms. It does not include any sliding element capable of increasing this size.

Figure 3 shows the cradle 11 in perspective. In this preferred embodiment of the invention, it is a removable cradle capable of being fixed to a truck by means of two quick coupling members 31₁ and 31₂. These two members 31₁ and 31₂ are fixed to plates placed projecting from a transverse beam 32.

The cradle comprises two longitudinal sleeves 33₁ and 33₂ whose rear end is fixed to the transverse beam 32. These longitudinal sleeves 33 fourr and 33₂ are horizontal, so that they are parallel to the plane of the truck bed. They are intended to receive the forks of the carriage.

According to the invention, the cradle further comprises two other sleeves 34₁ and 34₂ intended to receive the latches. They are substantially inclined, so that the distance between the sleeves 33₁ and 33₂ on the one hand and the sleeves 34₁ and 34₂ on the other hand increases appreciably from the rear of the cradle (corresponding to the vertical plane passing through the beam 32) towards the front of the cradle.

This cradle can for example be constructed as follows. Two vertical columns 35₁ and 35₂ are fixed under the transverse beam 32 by one of their ends. The other two ends are fixed to a lower transverse beam 36. The sleeves 34₁ and 34₂ are fixed to one of their ends simultaneously with the lower beam 36 and columns 35₁ and 35₂ respectively. The other ends of the sleeves 34₁ and 34₂ are connected by a second beam 37, itself connected to the sleeves 33₁ and 33₂ by two transverse elements 37₁ and 37₂.

Finally, the cradle comprises two vertical elements 39₁ and 39₂ fixed under the beam 22 and carrying two female guide and locking cones 310₁ and 310₂ whose role is explained below.

Figure 4 shows a part of the front of the carriage 12 in perspective. The forks, in the high position, are not shown so as to facilitate the description of the new elements of the invention.

This new elements include first of all the locks 41₁ and 41₂ which can move in sheaths 42 provided for this purpose, fixed under the carriage. These locks are intended to engage in the sleeves 34₁ and 34₂ (Figure 3).

Position sensors 43₁ and 43₂ make it possible in particular to detect the correct positioning of the latches, during attachment.

Finally, substantially vertical male cones 44₁ and 44₂ are fixed to the supports 45₁ and 45₂ of the front wheels. They are intended to engage in the female cones 310₁ and 310₂ (Figure 3).

FIGS. 5A to 5C illustrate the principle of the attachment of the carriage 12 to the truck 10 according to the invention.

Beforehand, and conventionally, the driver of the carriage 12 engages the forks 15 in the sleeves 14 (arrow 18, FIG. 1). Then, still in a conventional manner, it begins to lift the carriage 12 by commanding a movement of descent of the forks.

FIG. 5A presents a first new characteristic of the invention. The lifting operation is not carried out without checking the lateral position of the forks relative to the carriage. On the contrary, the operator precisely controls this position, so that the male cones 51 of the carriage engage in the female cones 52 of the cradle. This ensures the exact positioning of the carriage relative to the truck. Locking is not possible until the male cones 51 are not engaged in the female cones 52.

This particular positioning is determined during the design so as in particular to balance the masses of the carriage and to avoid overhangs and overshoots.

FIG. 5B illustrates the situation when this engagement male cone / female cone is carried out. It can be seen that in this situation, these male / female cone assemblies 51, 52 perform two other essential functions, in addition to lateral guidance, namely additional locking, allowing even better immobilization of the carriage, and precise vertical positioning putting the latches 53 opposite the sleeves 54.

It then suffices, as illustrated in FIG. 5C, to engage the latches 53 of the carriage in the sleeves 54 of the cradle. In this situation, the carriage is immobilized by the combination of forks 15 engaged in the sleeves 14, latches 53 engaged in the sleeves 54 and male cones 51 engaged in the female cones 52.

Advantageously, the engagement and disengagement of the latches 53 is done hydraulically, by exploiting the hydraulic energy available on the carriage. Thus, the operator can carry out all of the hooking and unhooking operations from his seat, without having to carry out any mechanical operation manually.

Position sensors 55 (only one being shown) make it possible to detect the complete engagement and disengagement of the latches, respectively. They control the supply of an indicator light which indicates to the operator that the locking or unlocking is complete. This further increases the security of the system, as the locks are not likely to be only partially engaged.

In a simplified embodiment, the movement of the latches can also be manual. In this case, the maneuver is a little more complex, but remains safe. Indeed, the operator does not need to slip under the truck or the cart, the locks being easily accessible. This maneuver is done for example at the rear of the carriage. It then suffices to push or pull the latches 53 toward you.

The dropout is of course symmetrical to the hanging.

Claims (10)

System for attaching a forklift (12) to the rear of a carrier vehicle (11), said carrier vehicle (11) comprising first and second sleeves (14; 33₁, 33₂) in which each fork ( 15; 41₁, 41₂) of said forklift (12) is capable of coming to engage,
characterized in that said carrier vehicle (10) comprises at least a third and a fourth sleeve (16; 34₁, 34₂; 54) for locking and centering, and in that said forklift (12) comprises at least two latches ( 17; 41₁, 41₂; 53) capable of sliding to engage respectively in said third and fourth sleeves (16; 34₁, 34₂; 54), so that said forklift (12) is hooked to said carrier vehicle (10) by at least four hooking elements (15, 17). Hanging system according to claim 1, characterized in that said third and fourth sleeves (16; 34₁, 34₂; 54) form an angle with said first and second sleeves (14; 33₁, 33₂) between 3 ° and 30 ° . Hanging system according to any one of claims 1 and 2, characterized in that said forklift (12) comprises at least a first element (44₁, 44₂; 51) for guiding and locking substantially vertical and in that said carrier vehicle (10) comprises at least a second element (310₁, 310₂; 52) for additional guiding and locking, said first element (44₁, 44₂; 51) for guiding and locking engaging in said second element (310₁, 310₂; 52) for guiding and locking when said forklift (12), the forks (15) of which are engaged in said first and second sleeves (14; 33₁, 33₂), is actuated upwards. Attachment system according to claim 3, characterized in that said first and second guide elements respectively comprise a male cone (44₁, 44₂; 51) and a female cone (310₁, 310₂; 52) complementary. Hanging system according to any one of claims 1 to 4, characterized in that said latches (17; 41₁, 41₂; 53) are moved hydraulically, using the hydraulic energy available on said forklift (12 ). Hanging system according to any one of claims 1 to 4, characterized in that said latches (17; 41₁, 41₂; 53) are moved manually. Latching system according to any one of claims 1 to 6, characterized in that it comprises at least one position sensor (43₁, 43₂; 55) delivering at least end of travel information of said latches (17; 41₁ , 41₂; 53). Hanging cradle (11; Figure 3) of a system according to any one of claims 1 to 7, intended to be fixed to said carrier vehicle (10) and comprising at least four sleeves provided for receiving respectively at least two forks and at least two sliding locking elements. Hanging cradle (11; Figure 3) according to claim 8, characterized in that it comprises unlockable fixing means (31₁, 31₂), so that it can be detached from said carrier vehicle (10). Forklift (12; Figure 4) of a system according to any one of claims 1 to 7, characterized in that it comprises at least two latches (17; 41₁, 41₂; 53) capable of coming to engage respectively in said third and fourth sleeves (16; 34₁, 34₂; 54).

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