FR3123909A1 - On-board pole-laying crane - Google Patents

Abstract

The invention relates to an on-board crane (1) for installing a pole (91), comprising: - a manipulation head (2), having: - an interface for securing (20) to an arm (10) of crane; -a post clamp (4); -a manipulation mechanism (3) connecting the clamp (4) to the securing interface (20), having a first articulation (31) configured to cause a first section (21) to pivot relative to the interface of connection (20) around a first axis (319), having a second articulation (32) configured to cause a second section (22) to pivot with respect to the first section around a second axis (329), having a third articulation (33) configured to pivot the clamp (4) relative to the second section around a third axis. Figure to be published with abstract: Fig. 2

Description

On-board pole-laying crane

The invention relates to cranes on board motor vehicles, and in particular to on-board cranes intended for installing poles.

The installation of metal, wood or composite poles in an urban environment is generally implemented as follows. A concrete screed is poured with screw bodies projecting upwards. A post with a base is placed vertically above the clevis and the screw bodies. The base has through holes. The post is manipulated to place the screw bodies through respective bores. The screws are then bolted in to hold the post in position.

The installation of wooden or concrete posts is generally implemented as follows. The posts are positioned in an excavation. The column is manipulated to place it vertically. Concrete is then poured into the excavation.

Handling poles is tricky for operators, as such poles can weigh several tons. It is therefore common to use cranes on trucks to handle such poles.

A known crane comprises an articulated arm, at the end of which a pole manipulation head is fixed. The manipulation head has a clamp that can be selectively tightened or loosened around a pole. The manipulator head is attached to the arm via first and second rotary joints. Each rotation of the joints is controlled by a control console. To install a post, the operator grabs the post placed horizontally using the clamp. The operator then lifts the post using the articulated arm of the crane. The operator then pivots the post to partially straighten it by commanding a rotation of the first joint. By ordering a rotation of the second joint, the operator places the post vertically to the bodies of the fixing screws. However, a practical problem is that the posts must be aligned with the screw bodies. The most common practice for the operator is to slightly tilt the post by means of one of the joints. Then, the operator commands a slight loosening of the post. The operator then manually rotates the post until it is aligned.

Such manipulation poses safety problems since the pole is poorly held during manipulation by the operator, which can cause a risk of a pole weighing several tons falling. In addition, the posts generally have a conical section. A good tightening of the clamp on the post then supposes to apply a significant tightening force to grip the widest section of the post in the clamp. Such tightening can cause damage to the surface of the post.

The invention aims to solve one or more of these drawbacks. The invention thus relates to an on-board crane for installing a pole, comprising:
- a manipulation head, presenting:
-an interface for securing to a crane arm;
-a post clamp;
-a manipulation mechanism connecting the clamp to the securing interface, having a first articulation configured to cause a first section to pivot relative to the securing interface around a first axis, having a second articulation configured to pivoting a second section with respect to the first section around a second axis, having a third articulation configured to cause the collet to pivot with respect to the second section around a third axis.

The invention also relates to the following variants. Those skilled in the art will understand that each of the characteristics of the following variants can be combined independently with the characteristics above, without however constituting an intermediate generalization.

According to a variant, at least one of the first to third joints comprises a wheel drive and endless screw.

According to yet another variant, said drive wheel and endless screw is motorized by a hydraulic motor controlled by a control circuit.

According to another variant, the crane further comprises at least one stop for restraining the rotation of the wheel and worm drive.

According to yet another variant, the first axis is perpendicular to the second axis and in which the third axis is perpendicular to the second axis.

According to a variant, the first axis is secant with the second axis, and in which the third axis is secant with the second axis.

According to yet another variant, the clamp comprises:
-a turntable;
-a support and a first jaw mounted to slide relative to the plate in a direction perpendicular to the third axis;
-a second jaw pivotally mounted relative to the support in a direction parallel to the third axis.

According to another variant, the collet further comprises first and second cylinders, configured to cause the support and the first jaw to slide in opposite directions.

According to yet another variant, the first and second jacks include force limiters.

Other characteristics and advantages of the invention will emerge clearly from the description which is given below, by way of indication and in no way limiting, with reference to the appended drawings, in which:

is a schematic representation of a vehicle fitted with a crane ready to be fitted with a manipulation head according to the invention;

and

are perspective views of a crane handling head according to one embodiment of the invention;

is a perspective view of a gripper of the manipulation head of the ;

is a perspective view of the clamp of the in the absence of the jaws;

is a perspective view of a clamp jaw support of the ;

is a schematic side view of the manipulation head in a first configuration;

is a schematic side view of the manipulation head in a second configuration;

is a schematic side view of the manipulation head in a third configuration.

The is a representation of a vehicle 92 equipped with an on-board crane 1. The on-board crane 1 comprises a crane arm 10 known per se, capable of lifting and moving loads. The crane 1 is configured to ensure the lifting and positioning of a post 91 resting on the ground. The post 91 is here provided with a base 93. The base 93 has several bores not shown.

To this end, the crane 1 according to the invention can receive a manipulation head 2, an example of which is illustrated in perspective in and 3. The manipulation head 2 comprises a connection interface 20, here including a crane extension that fits inside one end of the arm 10 of the crane 1. The crane extension can be locked in such a way known per se on arm 10.

The manipulation head 2 also comprises a clamp 4 for clamping the post 91. The clamping clamp 4 can be configured to apply a calibrated clamping force to the periphery of the post 91.

The manipulation head 2 also comprises a manipulation mechanism 3. The manipulation mechanism 3 connects the clamp 4 to the securing interface 20. The manipulation mechanism 3 has an articulation 31 configured to cause a first section 21 to pivot. with respect to the securing interface 20 around a first axis 319. The first axis 319 is here perpendicular to the direction of the arm 10. The displacement mechanism 3 has an articulation 32 configured to cause a second section 22 to pivot with respect to to the first section 21 around a third axis 329. The manipulation mechanism 3 also has a hinge 33 configured to cause the clamp 4 to pivot relative to the second section 22 around a third axis 339.

A control circuit 5 of the crane 1 and of the handling mechanism 3 is controlled via a control console 51 accessible to the operator. The operator can thus independently control the rotation of the joints 31 to 33. The operator can also control the lifting by the lifting arm 10.

Thus, by prior manipulation of the joints 31 and 33, the operator can place the post 91 in a raised position initially by means of the joint 31, then in a vertical position above the ground fixing screw bodies by means of the articulation 33. The operator can then pivot the post around the vertical direction by means of the second articulation 32, so as to position the bodies of the fixing screws opposite the bores of a base of the post 91. Such positioning can be achieved without loosening the clamp 4, and therefore without risk of manipulation for the operator. An example of handling a post 91 is detailed later with reference to Figures 7 to 9.

Advantageously, for the ease of use of the crane 1, the axis 319 is perpendicular to the axis 329 and the axis 339 is perpendicular to the axis 329. Advantageously, the axis 319 is secant with the axis 329 , and axis 339 intersects axis 329.

Joint 31 here comprises a wheel and worm drive. A worm 311 is rotatably mounted in a casing of section 21. The worm 311 is driven in rotation by a hydraulic motor 310 controlled by the control circuit 5. The worm 311 meshes with a wheel 312 housed in a casing of the securing interface 20. In the example illustrated, the joint 31 comprises two hydraulic motors and two wheel drives and endless screws positioned opposite each other. Such a configuration advantageously makes it possible to have a greater torque at the start of the post 91 manipulation cycle, in order to be able to lift the post 91 more easily.

Joint 32 here comprises a wheel and worm drive. A worm 321 is rotatably mounted in a housing of the section 21. The worm 321 is driven in rotation by a hydraulic motor 320 controlled by the control circuit 5. The worm 321 meshes with a wheel 322 housed in a casing of section 22.

Joint 33 here comprises a wheel and worm drive. A worm 331 is rotatably mounted in a housing of the gripper 4. The worm 331 is driven in rotation by a hydraulic motor 330 controlled by the control circuit 5. The worm 331 meshes with a wheel 332 housed in a casing of section 22.

In order to limit the amplitude of the rotations implemented by the joints 31 to 33, the manipulation head 2 advantageously comprises stops for clamping the rotations. Such stops are intended to limit unwanted and potentially dangerous manipulations of the manipulation head 2.

Thus, the securing interface 20 is provided with an abutment 201. The abutment 201 is intended to interfere with a part of the section 21, to limit the rotation around the axis 319. It is possible, for example, to provide an upper abutment for allow pivoting up to 90° to raise the section 21, and a bottom stop to allow pivoting up to -70° to lower the section 21. The stop 201 is here made in the form of a perforated sheet.

Section 21 includes a stop 211, here provided on a support plate of section 21. Section 22 includes a stop 221, here provided on a support plate of section 22. Stops 211 and 221 are configured to interfere for certain values of rotation around the axis 329.

The section 22 includes a stop 222, here provided on another support plate of the section 22. The clamp 4 includes stops 401, integral with a plate 40 detailed later. The stops 222 and 401 are configured to interfere for certain values of rotation around the axis 339.

As illustrated in Figures 4 and 5, the clamp 4 includes a plate 40. The clamp 4 also includes a jaw 41 and a jaw 42 positioned in opposition to grip a post. The jaw 41 breaks down into claws 411 and 412, positioned on either side of the axis 339. The jaw 42 breaks down into claws 421 and 422, positioned on either side of the axis 339. Clamp 4 also comprises a support 45 and an intermediate support 46.

The support 45 is slidably mounted relative to the plate 40 along an axis perpendicular to the axis 339. The support 45 is for example slidably mounted on crosspieces 402 and 403 secured to the plate 40. The support 45 is selectively driven in sliding via a jack 43. The claws 411 and 412 of the jaw 41 are fixed to the support 45 via bolts 49.

The support 46 is slidably mounted relative to the plate 40 along an axis perpendicular to the axis 339. The intermediate support 46 is for example slidably mounted on the crosspieces 402 and 403. The intermediate support 46 is selectively driven in sliding by the intermediary of a cylinder 44. A support 47 is pivotally mounted relative to the intermediate support 46, around an axis parallel to the axis 339.

The claws 421 and 422 of the jaw 41 are fixed on the support 47 by means of bolts 49. The claws 421 and 422 are positioned on either side of the axis of rotation of the support 47 with respect to the intermediate support 46.

To ensure the gripping of a post 91 with the clamp 4, the jaws 41 and 42 are previously separated from each other. Then, the cylinders 43 and 44 are driven to cause the supports 45 and 46 to slide towards each other, so as to enclose the post 91 between the jaws 41 and 42. Due to the pivoting of the support 47 relative to the support 46, the clamping of the jaws 41 and 42 adapts to a post 91 of conical shape.

The illustrates more details concerning the sliding mounting of the support 46 with respect to the crosspieces 402 and 403 and concerning the pivoting mounting of the support 47 with respect to the support 46. For this purpose, the support 46 comprises an elongated body, provided with brackets 462 at its ends. The support 47 is held between the body and the stirrups 462. Furthermore, the support 47 comprises a hub 471, housed in a bore of the support 46. The support 47 is thus guided in rotation relative to the support 46. Furthermore, the support 46 is provided with tubes 461 of square section, positioned on either side of the hub 471. The tubes 461 are intended to be crossed by the crosspieces 402 and 403 in order to ensure their sliding guidance with respect to the plate 40 .

In order to apply an identical and not excessive clamping force between the claws 411, 421 and the claws 412 and 422, the jacks 43 and 44 are advantageously fitted with force limiters or calibrated pressure limiters.

Claws 411, 412, 421 and 422 are advantageously removable, in order to be able to adapt to different post profiles. It is thus possible to use claws of different shapes, corresponding to the post to be gripped.

Figures 7 to 9 schematically illustrate a side view of a manipulation head 2 at different stages of movement of a post. To the , the clamp 4 encloses a post 91 in order to immobilize it. The post 91 is positioned horizontally, perpendicular to the arm of the crane, the end of which is materialized by the interface 20. During a first operation, the articulation 31 is pivoted around the axis 319 (approximately 90°) and the arm of the crane is raised to raise the post 91 relative to the ground. We then reach the arrangement illustrated in . During a second operation, the articulation 33 is pivoted around the axis 339 (by approximately 90°) to place the post 91 vertically. We then reach the arrangement illustrated in . The base of the post 91 can then be superposed on anchor screws in the ground. During a third operation, the articulation 32 is pivoted around the axis 329, so as to correctly position the orifices of the base of the post 91 opposite the anchoring screws in the ground. A positioning of the post 91 can thus be implemented in complete safety in order to bolt the base.

Claims (9)

On-board crane (1) for installing a post (91), characterized in that it comprises:
-a manipulation head (2), having:
-an attachment interface (20) to a crane arm (10);
-a clamp (4) for a post;
-a manipulation mechanism (3) connecting the clamp (4) to the securing interface (20), having a first articulation (31) configured to cause a first section (21) to pivot relative to the interface of connection (20) around a first axis (319), having a second articulation (32) configured to make a second section (22) pivot relative to the first section around a second axis (329), having a third articulation (33) configured to rotate the clamp (4) relative to the second section around a third axis. On-board crane (1) according to claim 1, wherein at least one of the first to third joints (31) comprises a wheel and worm drive. On-board crane (1) according to claim 2, wherein said worm wheel drive is powered by a hydraulic motor (310) controlled by a control circuit (5). On-board crane (1) according to claim 2 or 3, further comprising at least one stopper for restraining the rotation of the wheel and worm drive. An on-board crane (1) according to any preceding claim, wherein the first axis (319) is perpendicular to the second axis (329) and wherein the third axis (339) is perpendicular to the second axis (329). On-board crane (1) according to claim 5, in which the first axis (319) is secant with the second axis (329), and in which the third axis (339) is secant with the second axis (329). On-board crane (1) according to any one of the preceding claims, in which the clamp (4) comprises:
-a plate (40);
-a support (46) and a first jaw (41) mounted to slide relative to the plate (40) in a direction perpendicular to the third axis (339);
-a second jaw (42) pivotally mounted relative to the support (46) in a direction parallel to the third axis (339). On-board crane (1) according to Claim 7, in which the clamp (4) further comprises first and second cylinders, configured to cause the support and the first jaw to slide in opposite directions. On-board crane (1) according to claim 8, in which the first and second cylinders include load limiters.