FR3077064A1 - ARTICULATED ARROW LIFTING MACHINE - Google Patents

Abstract

The invention relates to a hoist (1) comprising: - a frame (2) comprising a base portion (3) resting on the ground (S), said base portion (3) being integral with a mast (5); ) of substantially vertical axis; an intermediate piece (7) mounted on an upper part (6) of the mast (5); an arrow (9) having a proximal end (11) pivotally mounted relative to said intermediate piece (7) about a substantially vertical pivot axis (V1) and a distal end (12) configured to allow the removable attachment of a tool, said boom (9) being formed of a plurality of successive segments (13a, 13b) hinged together, said segments (13a, 13b) being configured to define at least three specific operating positions of the machine of lifting.

Description

The present invention relates to a lifting machine, in particular a mini-crane.

Traditionally, lifting devices of the mini-crane type comprise on the one hand a chassis comprising a base part resting on the ground and integral with a mast of substantially vertical axis, and on the other hand a jib mounted on the chassis to lift a load. In general, the boom is rigid and it pivots about a substantially horizontal axis.

This type of mini-crane has the disadvantage of being equipped with a boom that is too slow in extension and not flexible enough to use to perform parts picking or machine loading operations productively. In addition, traditional arrows do not allow to reach a load located at the periphery and at the foot of the machine, which is a problem in small spaces.

The present invention therefore aims to provide a lifting device which overcomes the drawbacks mentioned above.

To this end, the invention relates to a lifting device comprising:

- A chassis comprising a base part resting on the ground, said base part being integral with a mast of substantially vertical axis;

- an intermediate piece mounted on an upper part of the mast;

- a boom having a proximal end pivotally mounted relative to said intermediate piece around a substantially vertical pivot axis and a distal end configured to allow the removable attachment of a tool, said boom being formed of a plurality of successive segments hinged together, said segments being configured to define at least three specific operating positions of the lifting machine, namely:

• a first operating position, called forward taut arrow position, in which the arrow is substantially aligned in a horizontal plane, the distance between the proximal and distal ends of the arrow being equal to a value Dmax;

• a second operating position, known as the down arrow position, in which the arrow is substantially aligned in a vertical plane and the distal end of the arrow is close to the ground, the distance between the proximal and distal ends of the arrow being less at the Dmax value;

• a third operating position, called the storage position, in which the distal end of the boom is close to the ground, the distance relative to the ground between the proximal and distal ends of the boom being minimal.

Thus, when the hoist is in its second operating position, the boom will be correctly positioned to lift a load that is close to the hoist. The load can subsequently be lifted, in particular when the machine passes from its second operating position to its first operating position. As the boom can pivot at its proximal end, the user can also move the load around its original position without lifting it. He can also lift the load first, then move it in rotation from this high position, and finally place it on the ground in the desired location.

In a preferred embodiment of the invention, the lifting device will be configured in such a way that each segment of the boom is pivotally mounted with respect to an adjacent segment around a substantially vertical axis.

This will allow the boom to have a very wide range of movement around its point of articulation with the intermediate piece.

Advantageously, friction means acting on the axis of the pivot link connecting two adjacent segments will be provided to allow the resistance of said link to be varied to a pivoting movement around its axis.

These friction means will thus make it possible to sequence the movement of the arrow around its pivot axis so as to facilitate the manipulation of the arrow by the user.

In a specific configuration of the lifting device, each segment will have a deformable parallelogram structure, making it possible to vary the inclination of said segment relative to a horizontal plane.

This configuration will in particular further improve the movement of the load. In particular, this configuration will limit tilting forwards or backwards of the load when it is lifted by the boom.

In another specific configuration of the lifting machine, each segment will also include an actuator capable of modifying the inclination of said segment relative to the horizontal, each actuator preferably being remotely controllable by means of a wired remote control fixed to the distal end of the arrow.

This configuration will allow a user to control the raising and lowering of the load from the end of the boom.

Other characteristics and advantages will emerge clearly from the description below of an embodiment of a lifting device according to the invention, given by way of nonlimiting example, with reference to the appended drawings in which:

Figures 1 and 3 to 5 are side views of a lifting device according to an embodiment of the invention and according to several specific operating positions of the lifting device;

Figure 2 is a front view of the hoist shown in Figure 1, the boom having rotated a quarter of a turn;

Figure 6 is a perspective view of the hoist in the operating position shown in Figure 5;

Figures 7 and 7a are respectively side and sectional views of a pivot connection used in the hoist shown in Figures 1 to 6 to connect two adjacent segments of the boom.

Figure 1 shows a lifting device 1 according to an embodiment of the invention, of the mini self-propelled crane type.

It should be noted that the description is made in relation to a Cartesian frame of reference linked to the lifting device, the X axis being oriented in the longitudinal direction of the lifting device, the Y axis being oriented in the transverse direction of the lifting device, and the Z axis being oriented in the vertical direction of the lifting device. Thus, the longitudinal, transverse, vertical, front or rear, top or bottom orientations, directions and displacements are defined with respect to this reference system.

The lifting machine 1 firstly comprises a chassis 2. The chassis 2 comprises a base part 3 comprising at its front part a platform 14 mounted on two wheels 15, said platform 14 being able to serve as a zone for storage for loads to be transported or unloaded. The rear part of the base part 3 is integral with a rear axle 16 equipped with a wheel 17 mounted movable in rotation about a substantially horizontal axis. The orientation of the wheel 17 can be modified by means of an operating lever 18. The operating lever 18 can advantageously be equipped with several control buttons so as to allow an operator to carry out a certain number of operations at distance. In particular, in the case where the lifting machine 1 will be equipped with an electric motor intended to turn the wheel 17, buttons may advantageously be provided on the operating lever 18 to control the starting and stopping of the motor.

As shown in FIG. 2, the lifting machine 1 is advantageously equipped with two stabilizing feet 19 which can be moved relative to the chassis 2 so as to be positioned at a distance from the ground when the operator wants to move the lifting machine .

The chassis 2 also comprises a mast 5 having a substantially vertical axis. In the configuration shown, the mast 5 can move along its axis between a low position, as shown in Figures 2, 3 and 5, and a high position, as shown in Figures 1 and

4. The motor means allowing this movement will advantageously be arranged inside the chassis 2 and will be controllable by means of a wired remote control. On the upper part 6 of the mast 5 is mounted an intermediate piece 7. The intermediate piece 7 will advantageously be mounted so as to be able to rotate on the mast 5 around a vertical axis V0, in particular by means of a rotary joint. The angular amplitude of the rotational movement of the intermediate piece 7 may be limited by any suitable means, in particular by means of stops provided at the upper part 6 of the mast 5. In the configuration shown, the intermediate part 7 has a shape curve directed downwards, so that said intermediate piece 7 has a lower end 8 which is positioned at a distance from the mast 5 and below the upper part 6 of the latter. On this lower end 8 is mounted an arrow 9.

In the configuration shown, the arrow 9 has a proximal end 11 which is pivotally mounted on the lower end 8 of the intermediate piece 7 about a substantially vertical pivot axis V1 and a distal end 12 formed by a head element, said head element being provided with fixing means 10 allowing the removable fixing of a tool at the end of the arrow 9. The tool may vary depending on the intended use. It could for example consist of a clamp, a fork, or a hook. The arrow 9 also has an articulated structure comprising two adjacent segments 13a, 13b connected to each other at their junction end by means of a pivot connection with a substantially vertical axis V2, one of the segments 13a also being mounted pivotally on the intermediate piece 7 around the axis V1 and the other segment 13b being pivotally mounted to the head element 12 around a substantially vertical axis V3. This successive pivoting link combination gives boom 9 great maneuverability and a large amplitude of movement along a horizontal plane H1 on which the two segments 13a, 13b are aligned. The displacement of the segments 13a, 13b and of the head element 12 in the horizontal plane H1 may in particular be carried out by means of a handle (not shown) provided at the level of the head element 12, which the operator can handle by hand. In another possible configuration of the invention, it will also be possible to envisage a motorized movement of the segments 13a, 13b and of the head element 12 around the axes V1, V2 and V3 respectively. In this case, the arrow 9 and / or the intermediate part 7 will advantageously be equipped with indexing fingers and contact sensors so as to detect when the segments 13a, 13b and / or the head element 12 reach a position of reference corresponding to a specific operating position of the lifting device. It will also be possible to angularly limit the rotation of said segments 13a and 13b and / or of the head element 12 around the axes V1, V2 and V3 respectively by means of stops integrated in the segments themselves or in the intermediate part 7 in the case of segment 13a. Preferably, these stops will be configured to limit the angular amplitude of the movement of the segments to an angle between -90 ° and + 90 ° around the position shown in Figure 1.

Referring to Figure 2, there is shown the hoist 1 when, from the position shown in Figure 1, the intermediate piece 7 has pivoted about the axis V0 at an angle of 90 ° and the mast 5 has been lowered to its lower position. It can be seen that, in this low position of the mast 5, the distal end 12 of the arrow 9 is still too far from the ground S to be able to lift loads which would be placed there. In order to bring the distal end 12 closer to the ground, each segment 13a, 13b will advantageously have means making it possible to vary its inclination relative to the horizontal. In the configuration shown, these means consist in configuring each segment 13a, 13b according to a deformable parallelogram structure. Such a structure is in particular defined by two end crossmembers 134, 135 arranged opposite each end of the segment. The cross member 134, which is closer to the proximal end 11 of the arrow 9, pivotally supports the rear ends 131a, 132a of a pair of arms 131, 132 arranged in parallel in a vertical plane, the front ends 131b, 132b of said arms 131, 132 being pivotally connected to the cross-member 135, which is closer to the distal end 12 of the arrow 9. In the advantageous configuration shown, each segment 13a, 13b also has a second pair of parallel arms 131, 132, defining a similar structure of deformable parallelogram, said second pair being spaced from the first pair in the transverse direction, the free space between said pairs of arms 131, 132 serving as a housing for a hydraulic cylinder 133, the ends of which are respectively pivotally mounted on the end crosspieces 134, 135 of the segment 13a or 13b. Thus, it is possible to deform each of the deformable parallelograms by acting on the extension of the rod of the jack 133. This deformation will therefore induce a corresponding modification of the inclination of the arms 131 and 132, and therefore of the segment 13a or 13b, by compared to the horizontal. It is clear that other types of actuators may be used in place of the hydraulic cylinder 133 so as to modify the inclination of the segments 13a, 13b relative to the horizontal. Advantageously, each actuator 133 or actuator can be controlled remotely by means of a wired remote control attached to the end 12 of the arrow 9.

In the embodiment shown, the arrow 9 has only two segments 13a, 13b. However, the hoist of the invention could also be equipped with a boom having more than 2 consecutive segments hinged together.

In another advantageous configuration of the invention, and as shown in detail in FIGS. 7 and 7a, the pivot link 136 connecting the end crosspieces 134, 135 respective of two adjacent segments is configured to allow an operator to adjust its hardness, that is to say its resistance to a pivoting movement around a substantially vertical axis V2. To this end, the pivot link 136 comprises tapered roller bearings 138a, 138b, respectively upper and lower, arranged in opposition, each of the rollers resting on shoulders formed at the end crosspieces 134, 135. The crosspiece 134 has in particular a shaft 137 threaded at its free end on which is screwed at least one nut

139, said nut 139 coming to press on several Belleville washers 142 which exert an axial thrust force downwards against a support piece 140 of substantially annular shape. Said support piece 140 has an outer edge configured as a bevel, said edge abutting against a shoulder 141 also bevel and integral with the crosspiece 135. Thus, by more or less screwing the nut 139, it is possible to exert a variable friction force on the cross-member 135 via the support piece

140, which changes the hardness of the pivot link 136.

The operating position shown in FIG. 3, called the arrow position low position, is reached when, from the position shown in FIG. 1, the operator actuates the jacks of each of the segments 13a, 13b so as to modify their inclination with respect to the horizontal. In this position, the head element 12 is close to the ground S, the height δ H separating the connection point 10 for the tool from the ground S being as small as possible. Furthermore, the distance D separating said head element 12 from the pivot link 11 connecting the arrow 9 to the intermediate piece 7 is shorter than the extension Dmax of the arrow 9 in its arrow position stretched forward. In this position, the lifting device 1 is correctly positioned to lift a load which would be placed on the ground.

The operator can then lift said load by acting on the cylinders of the segments 13a, 13b so as to reverse their inclination and reach, for example, the position shown in FIG. 4 in which the connection point 10 for the tool is higher than the upper surface 6 of the mast 5.

Referring to Figures 5 and 6, there is shown the so-called storage position of the lifting device according to the invention. In this position, the head element 12 of the arrow 9 is close to the ground S, the height δ H separating the connection point 10 for the tool from the ground S being as small as possible. Unlike the position shown in FIG. 3, the head element 12 has been manually oriented by the operator so that the connection point 10 is directed towards the rear of the lifting machine, thus limiting its bulk. in the longitudinal direction. Thus, the distance Dr relative to the ground between the head element 12 of the pivot link 11 will be as small as possible. The overall height and in the transverse direction of the lifting gear is also limited to the maximum in this storage position due to the optimized orientation of the segments 13a and 13b of the boom 9.

The overall height is also limited by the fact that the proximal end 11 of the boom 9 is positioned under the upper part 6 of the mast

5.

Of course, the invention is in no way limited to the embodiment described above, this embodiment having been given only by way of example. Modifications are possible, in particular from the point of view of the constitution of the various elements, or by the substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

Claims (17)

1. Lifting device (1) comprising: a frame (2) comprising a base part (3) resting on the ground (S), said base part (3) being integral with a mast (5) of substantially vertical axis; an intermediate piece (7) mounted on an upper part (6) of the mast (5); a boom (9) having a proximal end (11) pivotally mounted relative to said intermediate piece (7) about a pivot axis (V1) substantially vertical and a distal end (12) configured to allow the removable fixing of a tool, said arrow (9) being formed of a plurality of successive segments (13a, 13b) hinged together, said segments (13a, 13b) being configured to define at least three specific operating positions of the lifting machine , to know : • a first operating position, known as the forward taut arrow position, in which the arrow (9) is substantially aligned in a horizontal plane (H1), the distance between the proximal (11) and distal (12) ends of the arrow (9) being equal to a value Dmax; • a second operating position, called arrow position low position, in which the arrow (9) is substantially aligned in a vertical plane and the distal end (12) of the arrow (9) is close to the ground (S), the distance (D) between the proximal (11) and distal (12) ends of the arrow (9) being less than the value Dmax; • a third operating position, called the storage position, in which the distal end (12) of the arrow (9) is close to the ground (S), the distance (Dr) relative to the ground between the proximal ends (11) and distal (12) of the arrow (9) being minimal. 2. Lifting device (1) according to claim 1, wherein each segment (13a, 13b) of the boom (9) is pivotally mounted relative to an adjacent segment around a substantially vertical axis (V2). 3. lifting device (1) according to claim 2, wherein the pivot link (136) connecting two adjacent segments (13a, 13b) is configurable by friction means (139, 140, 141) for varying the resistance from said link (136) to a movement pivoting about its axis (V2). 4. lifting device (1) according to claim 3, wherein the friction means comprise at least one nut (139) bearing against a washer (142) which is itself bearing against a support piece ( 140) having an outer edge in contact with a beveled shoulder (141) formed on one of the segments (13a, 13b), the tightening of the nut increasing the friction between said bearing piece (140) and said shoulder ( 141). 5. Lifting device (1) according to one of the preceding claims, in which each segment (13a, 13b) has a deformable parallelogram structure, making it possible to vary the inclination of said segment relative to a horizontal plane. 6. Lifting device (1) according to claim 5, wherein each segment (13a, 13b) comprises an actuator (133) capable of modifying the inclination of said segment relative to the horizontal. 7. Lifting device (1) according to claim 6, in which the actuator is a jack (133) of hydraulic type connected at its two ends to two end crosspieces (134, 135) of the segment (13a, 13b) , said crosspieces (134, 135) pivotally supporting two pairs of parallel arms (131, 132) arranged on either side of the jack (133). 8. Lifting device (1) according to one of claims 6 and 7, wherein each actuator (133) is remotely controllable by means of a wired remote control attached to the distal end (12) of the boom (9 ). 9. Lifting device (1) according to one of the preceding claims, in which the distal end (12) of the boom (9) comprises a head element supporting a handle, said handle allowing the manual movement of the boom ( 9) by a user. 10. Lifting device (1) according to one of the preceding claims, in which the chassis (2) is mounted on wheels (15, 17) so as to allow the movement of the lifting device on the ground (S) . 11. Lifting device (1) according to one of the preceding claims, further comprising two stabilizing feet (19) movable relative to the frame (2) between a deployed position in which a free end of the stabilizing feet (19) is intended coming to bear against the ground (S) and a folded position in which this free end is intended to be arranged at a distance from the ground (S). 12. Lifting device (1) according to one of the preceding claims, in which the mast (5) is vertically movable. 13. Lifting device (1) according to one of the preceding claims, wherein the proximal end (11) of the boom (9) is positioned under the upper part (6) of the mast (5), thereby reducing the overall dimensions of the lifting device in its storage position. 14. Lifting device (1) according to one of the preceding claims, further comprising a platform (14) integral with the base part (3) of the chassis (2), said platform (4) making it possible to deposit loads intended to be transported by the lifting device. 15. Lifting device (1) according to one of the preceding claims, in which the boom (9) and / or the intermediate piece (7) are equipped with indexing fingers and contact sensors capable of detecting said fingers d indexing in a specific configuration of the boom (9), said configuration possibly corresponding in particular to at least one of said specific operating positions of the lifting machine. 16. Lifting device (1) according to one of the preceding claims, in which the segments (13a, 13b) of the boom (9) are equipped with stops capable of angularly limiting the rotation of said segments (13a, 13b) around 'a substantially vertical axis (V1, V2, V3). 17. Lifting device (1) according to one of the preceding claims, in which the intermediate piece (7) is mounted on the mast (5) so as to be able to rotate about a vertical axis (VO).