EP4686692A1

EP4686692A1 - Rotatable stabiliser

Info

Publication number: EP4686692A1
Application number: EP25192366.0A
Authority: EP
Inventors: Andrea MARCHESI
Original assignee: Marchesi Gru Srl
Current assignee: Marchesi Gru Srl
Priority date: 2024-08-01
Filing date: 2025-07-29
Publication date: 2026-02-04

Abstract

Stabiliser unit (1) for a truck-mounted crane, comprising:
a support structure (10) and at least one stabiliser leg (20) rotatably mounted on one side of the support structure (10) between a transport position and a work position, in which it is in contact with the ground;
said stabiliser leg (20) being extendible/retractable along a main longitudinal direction between an open configuration and a closed configuration,
said stabiliser leg (20) comprising:
- a first member (21) having a head (21a) rotatably mounted on the support structure(10);
- a second member (22) connected to the first member (21);
- a stabiliser foot (23) situated on the opposite side to the first member (21);

said second member (22) comprising a first hydraulic jack (24) operatively associated with the first member (21) so as to be selectively engageable in the head (21a) to prevent rotation of the stabiliser leg (20) with respect to the support structure (10);
said second member (22) comprising a second hydraulic jack (25) operatively associated with the stabiliser foot (23) to move it towards/away from the first member (21) so that the stabiliser leg (20) is movable between said open and closed configurations;
a control unit (30) configured at least to control the first hydraulic jack (24) in engagement with/disengagement from the head (21a).

Description

The present invention relates to a stabiliser unit for a truck-mounted crane. In particular, the present invention can be applied in lifting equipment or loading cranes.
In this sector, it is known to use stabilisers in order to guarantee the stability requirements of the crane during its operation, discharging the forces onto the ground, and levelling of the base.
The known stabilisers include a type on which the stabiliser leg is mounted rotatably on the support. As a result of this assembly, the regulations require the presence of a locking device. The known solutions use a locking pin to be inserted manually. This means that the operator personally has to get down from the control position to take action on said pin.
In this context, the technical task at the basis of the present invention is to propose a stabiliser unit for a truck-mounted crane which overcomes the aforementioned drawbacks of the prior art.
In particular, an object of the present invention is to propose a stabiliser unit for a truck-mounted crane that can be controlled by the operator directly from the control position.
The technical task set and the objects specified are substantially achieved by a stabiliser unit for a truck-mounted crane, comprising the technical features set out in one or more of the appended claims.
Further features and advantages of the present invention will become more apparent from the indicative and thus non-limiting description of a preferred, but not exclusive, embodiment of a stabiliser unit for a truck-mounted crane, as illustrated in the appended drawings, in which:

Figure 1 illustrates a stabiliser unit according to the present invention, in a partially exploded perspective view;
Figure 2 illustrates the stabiliser unit of Figure 1, with the stabiliser leg broken down into a first member and a second member;
Figures 3 and 4 illustrate two sectional front views of the stabiliser leg of the stabiliser unit of Figure 1, respectively in closed and open configuration.

With reference to the figures, number 1 indicates a stabiliser unit for a truck-mounted crane.
The stabiliser unit 1 comprises a support structure 10 and at least one stabiliser leg 20 rotatably mounted on one side of the support structure 10 so as to be movable between a transport or rest position, in which it is not in contact with the ground and is possibly raised, and a work or support position, in which it is in contact with the ground and acts as a support.
In particular, the stabiliser leg 20 extends along a main longitudinal direction, which is substantially vertical in the operating condition. The stabiliser leg 20 is extendible/retractable along such direction between an open configuration and a closed configuration. Typically, the open condition (which corresponds with an ample extension; it can sometimes correspond with a maximum extension, but typically the stabiliser encounters the ground before arriving at the maximum extension) is used in the work position; the closed condition (which can correspond with a minimum extension) is used, on the other hand, in the transport position.
Opportunely, there are two stabiliser legs 20 and they are located on opposite sides of the support structure 10.
Preferably, the support structure 10 has a fulcrum 11 on which the stabiliser leg 20 is mounted rotatably.
The stabiliser leg 20 comprises a first member 21 having a head 21a rotatably mounted on the support structure 10. In particular, the head 21a is connected to the fulcrum 11.
The stabiliser leg 20 comprises a second member 22 connected to the first member 21.
Preferably, the second member 22 is connected to the first in a non-permanent way. The term "in a non-permanent way" means a connection that allows decoupling without compromising the components themselves, for example by means of a pin, thread, Seeger ring, etc.
Alternatively, the second member 22 is connected in a permanent way to the first, for example through welding.
The stabiliser leg 20 comprises a stabiliser foot 23 situated on the opposite side to the first member 21, in particular to the head 21a. Preferably, the stabiliser leg 23 can be mounted at one end of the second member 22 or of further members interposed between the second member 22 and the stabiliser foot 23.
The second member 22 comprises a first hydraulic jack 24 and a second hydraulic jack 25.
The first hydraulic jack 24 is operatively associated with the first member 21 so as to be selectively engageable in the head 21a to prevent rotation of the stabiliser leg 20 with respect to the support structure 10.
The second hydraulic jack 25 is operatively associated with the stabiliser foot 23 to move it towards/away from the first member 21. In other words, the second hydraulic jack 25 performs the movement of extraction/retraction of the stabiliser leg 20 between the open position and the closed one. In particular, a movement of the stabiliser leg 23 away from the first member 21 corresponds with an extension of the stabiliser leg 20 (i.e. elongation), until the open configuration is reached.
It should be noted that the reference to the first member 21 is arbitrarily chosen, as it is a component solidly constrained to the support structure 10 and therefore fixed. Any other component that does not change its height during use can be considered.
In yet other words, the second hydraulic jack 25 causes a telescopic elongation of the stabiliser leg 20.
In particular, the second hydraulic jack 25 can act directly on the stabiliser foot 23 (i.e. the stabiliser foot 23 is mounted directly on one end of the second hydraulic jack 25) or through interposed jacks.
The second hydraulic jack 25 therefore performs the actual stabilisation function.
Opportunely, with respect to the first member 21, the first hydraulic jack 24 and the second hydraulic jack 25 act in two opposing directions. The first hydraulic jack 24 extends upwards, i.e. towards the head 21a for coupling, the second hydraulic jack 25 extends downwards, i.e. away from the head 21a to take the stabiliser leg 23 into contact with the ground.
In accordance with one embodiment, the first hydraulic jack 24 comprises a first stem 26 slidable towards/away from the head 21a of the first member 21. The first stem 26 is configurable in at least a first engagement position, in which the first stem 26 is engaged in the head 21a and rotation of the stabiliser leg 20 with respect to the support structure 10 is prevented, and a second removed position, in which the first stem 26 is moved away and disengaged from the head 21a, so the aforesaid rotation is permitted. Opportunely, the first stem 26 is slidable inside a cylinder 27 of the first hydraulic jack 24.
The stabiliser unit 1 comprises a control unit 30 configured to control the first hydraulic jack 24 in engagement with/disengagement from the head 21a. In particular, the control unit 30 controls the first hydraulic jack so that the first stem 25 passes from one of the aforementioned positions to the other, and vice versa.
In this manner, an operator is able remotely to lock (stem in the first engagement position) or enable (stem in the second removed position) rotation of the stabiliser leg 20 with respect to the support structure 10. The chosen structure of the two members 21, 22, of which one selectively engageable in the other, keeps the structure of the stabiliser leg 20 simple. In accordance with one embodiment, the second hydraulic jack 25 comprises a second stem 28 slidable towards/away from the first member 21. Preferably, the stabiliser leg 23 is mounted on one end of the second stem 28.
Opportunely, the second stem 28 is slidably mounted inside a cylinder 29 of the second hydraulic jack 25.
In the embodiment illustrated, there is a single cylinder for the first and second hydraulic jack 24, 25 of the second member 22.
Preferably, the first stem 26 extends in a direction substantially parallel to the main longitudinal direction of the stabiliser leg 20.
Preferably, the second stem 28 extends in a direction substantially parallel to the main longitudinal direction of the stabiliser leg 20.
Preferably, the first stem 26 and the second stem 28 are arranged so as to be substantially one the extension of the other.
Preferably, the first stem 26 and the second stem 28 are substantially aligned along the axes, i.e. coaxial. The invention also works net of a slight offset.
Preferably, the control unit 30 is also configured to control the second hydraulic jack 25.
Preferably, the control unit 30 is also configured to control the stabiliser leg 20 in rotation with respect to the support structure 10.
Preferably, the stabiliser unit 1 comprises a first hydraulic circuit (not illustrated) associated with the first hydraulic jack 24 and a second hydraulic circuit (not illustrated) associated with the second hydraulic jack 25.
More preferably, the first hydraulic jack 24 and the second hydraulic jack 25 share the same hydraulic circuit. Preferably, the single hydraulic circuit also governs rotation of the stabiliser leg 20.
The control unit 30 imparts the aforesaid movements by controlling the single hydraulic circuit.
Consider the stabiliser leg 20 in the transport position, in which the stabiliser leg 20 is in the reduced extension condition, sometimes minimal (closed configuration) and possibly rotated upwards. In response to the signal to take the stabiliser leg 20 into the work position, the control unit 30 controls the second stem 28 in extension, the possible rotation of the stabiliser leg 20 with respect to the support structure 10 and subsequently the first stem 26 towards the first engagement position, so that it engages in the fulcrum 11 and prevents rotation.
Consider the stabiliser leg 20 in the work position, in which the stabiliser leg 20 is in the large extension condition (open configuration), sometimes maximum and in contact with the ground. In response to the signal to take the stabiliser leg 20 into the transport position, the control unit 30 controls the first stem 26 towards the second removed position (by retracting, it disengages the head 21a and allows rotation of the stabiliser leg 20 with respect to the support structure 10), the second stem 28 to retract and possible rotation of the stabiliser leg 20 with respect to the support structure 10.
The characteristics of the stabiliser unit for a crane according to the present invention are clear from the description, as are the advantages.
In particular, the stabiliser leg divided into two members reversibly connected to each other, of which one selectively engageable in the other (which in turn is rotatably mounted onto the support structure) allows locking means to lock rotation of the stabiliser leg to be defined, selectively activatable by an operator remotely (i.e. from inside the cabin), without the need for manual intervention.
Furthermore, the aforesaid advantage is obtained by the proposed invention while simultaneously maintaining a slender, simple and efficient structure of the stabiliser leg.

Claims

A stabiliser unit (1) for a truck-mounted crane, comprising:
a support structure (10);

at least one stabiliser leg (20) rotatably mounted on one side of the support structure (10) so as to be movable between a transport position, in which it is not in contact with the ground and is possibly raised upwards, and a work position, in which it is in contact with the ground and acts as a support;

said stabiliser leg (20) having extension along a main longitudinal direction, said stabiliser leg (20) being extendible/retractable along said main longitudinal direction between an open configuration and a closed configuration,

said stabiliser leg (20) comprising:
- a first member (21) having a head (21a) rotatably mounted on the support structure(10);

- a second member (22) connected to the first member (21);

- a stabiliser foot (23) situated on the opposite side to the first member (21);

said second member (22) comprising a first hydraulic jack (24) operatively associated with the first member (21) so as to be selectively engageable in the head (21a) to prevent rotation of the stabiliser leg (20) with respect to the support structure (10);

said second member (22) comprising a second hydraulic jack (25) operatively associated with the stabiliser foot (23) to move it towards/away from the first member (21) so that the stabiliser leg (20) is movable between said open and closed configurations;

a control unit (30) configured at least to control the first hydraulic jack (24) in engagement with/disengagement from the head (21a).
The stabiliser unit (1) according to claim 1, wherein the first hydraulic jack (24) comprises a first stem (26) slidable towards/away from the first member (21) so as to be configurable in at least a first engagement position, in which the first stem (26) is engaged in the head (21a) and rotation of the stabiliser leg (20) with respect to the support structure (10) is prevented, and a second removed position, in which the first stem (26) is moved away and disengaged from the head (21a).
The stabiliser unit (1) according to claim 1 or 2, wherein the second hydraulic jack (25) comprises a second stem (28) slidable towards/away from the first member (21), said stabiliser foot (23) being mounted on one end of the second stem (28).
The stabiliser unit (1) according to claim 3 when it depends on claim 2, wherein the first stem (26) and the second stem (28) are arranged so as to be substantially one an extension of the other.
The stabiliser unit (1) according to any one of the preceding claims, wherein the control unit (30) is configured to control a hydraulic circuit associated with the first hydraulic jack (24).
The stabiliser unit (1) according to any one of the preceding claims, wherein the first hydraulic jack (24) and the second hydraulic jack (25) share the same hydraulic circuit.
The stabiliser unit (1) according to any one of the preceding claims, wherein the first hydraulic jack (24) and the second hydraulic jack (25) act in two opposing directions.
The stabiliser unit (1) according to any one of the preceding claims, wherein the stabiliser legs (20) are two and are located on opposite sides of the support structure (10).
A truck-mounted crane comprising a stabiliser unit (1) according to any one of the preceding claims.