CN110121478B

CN110121478B - Load handling tool and hydraulic crane comprising such a load handling tool

Info

Publication number: CN110121478B
Application number: CN201780075884.9A
Authority: CN
Inventors: P.斯维德
Original assignee: Cargotec Patenter AB
Current assignee: Hilbert Ltd.
Priority date: 2016-12-09
Filing date: 2017-11-21
Publication date: 2020-05-29
Anticipated expiration: 2037-11-21
Also published as: CN110121478A; EP3333112B1; DK3333112T3; EP3333112A1; WO2018104042A1

Abstract

A load handling tool is attached to a crane boom and comprises first and second jaws (10, 30) pivotably connected to a carrier head (2) via respective pivot arms (11, 31) and actuating means (4) for pivoting the pivot arms and jaws relative to the carrier head. Each jaw (10, 30) is hingedly connected to an associated pivot arm (11, 31) and is pivotable relative to the pivot arms between a folded-down working position and an folded-up storage position, wherein the jaws are configured to be positioned between the pivot arms and to lie opposite each other in the folded-up storage position. In the folded-down working position, each jaw can be locked to the associated pivot arm by a locking device (14, 34). The invention also relates to a hydraulic crane provided with such a load handling tool.

Description

Load handling tool and hydraulic crane comprising such a load handling tool

Technical Field

The present invention relates to load handling tools. The invention also relates to a hydraulic crane comprising such a load handling tool.

Background

A common lorry-mounted crane may be provided with a load handling tool mounted to the outer end of a crane boom in the form of a so-called outer boom which is telescopically extendable and hingedly connected to another crane boom in the form of a so-called inner boom which in turn is hingedly connected to a rotatable column of the crane.

Load handling tools are previously known from EP 2778109 a 1. This previously known load handling tool has the form of a clamshell bucket with an open shell and is intended to be mounted to a crane jib, wherein one of the bucket jaws (jaw) of the clamshell bucket is provided with a recess for receiving a part of the crane jib in order to allow the crane jib and the clamshell bucket to assume a compact parking position. The clamshell bucket disclosed in EP 2778109 a1 is particularly suitable for use with so-called Z-cranes, which are hydraulic lorry-mounted cranes of the type shown in EP 1475345A 1 and US 4183712 a, wherein the inner and outer booms of the crane are foldable into a compact Z-parking position when the crane is to be transported or stored. When the outer boom of a Z-type crane is moved between the working position and the rest position, the tip of the outer boom will never pass at the side of the crane column, which means that a clamshell mounted to the outer end of the outer boom will never interfere with the column when the outer boom is moved between the working position and the rest position.

There is also another conventional type of hydraulic lorry-mounted crane, named hereinafter as collapsible knuckle boom crane, where the outer boom collapses in the opposite direction in relation to the inner boom when moving into a parking position, as compared to the outer boom of a Z-type crane. Such a foldable knuckle boom crane is shown for example in EP 0360071 a1 and EP 1580159 a 1. When the outer boom of a foldable knuckle boom crane of this type is moved between the working position and the parking position, the tip of the outer boom will pass at the side of the crane column, which means that a clamshell mounted to the outer end of the outer boom will interfere with the column when the outer boom is moved between the working position and the parking position. Thus, the clamshell must be removed from the crane before the outer boom is moved from the working position to the parking position. Removing the clamshell from the outer boom constitutes an undesirable time consuming task for the crane operator and means that space on the truck must be taken up for storing the removed clamshell.

Disclosure of Invention

It is an object of the present invention to provide a solution to the above problems.

According to the invention, this object is achieved by means of a load handling tool having the following features:

a load handling tool attached to a crane boom, the load handling tool comprising:

-a carrier head configured for connection to a crane boom;

-a first jaw and a second jaw positioned relative to each other, the first jaw being pivotably connected to the carrier head via a first pivot arm and the second jaw being pivotably connected to the carrier head via a second pivot arm, allowing the jaws to pivot towards each other for gripping a load and away from each other for releasing the gripped load, each pivot arm having a first end facing the carrier head and an opposite second end, wherein each pivot arm is pivotably connected at its first end to the carrier head; and the number of the first and second groups,

-actuating means for pivoting the pivot arm and thereby the jaw relative to the carrier head,

the method is characterized in that:

-each pivot arm is hingedly connected at its second end to an associated jaw, allowing the jaws to pivot relative to the pivot arms between a folded down working position and an folded up storage position, wherein the jaws are configured to be positioned between the pivot arms and to lie opposite each other in the folded up storage position; and

the load handling tool comprises first and second locking means for locking the first jaw to the first pivot arm in the folded down working position, and the second locking means for locking the second jaw to the second pivot arm in the folded down working position.

The load handling tool of the present invention comprises:

-a carrier head configured for connection to a crane boom;

-first and second jaws positioned relative to each other, the first jaw being pivotably connected to the carrier head via a first pivot arm and the second jaw being pivotably connected to the carrier head via a second pivot arm, allowing the jaws to pivot towards each other for gripping a load and away from each other for releasing the gripped load, each pivot arm having a first end facing the carrier head and an opposite second end, wherein each pivot arm is pivotably connected at its first end to the carrier head; and the number of the first and second groups,

actuating means for pivoting the pivot arm, and thereby the jaw, relative to the carrier head.

Each pivot arm is hingedly connected at its second end to an associated jaw, allowing the jaws to pivot relative to the pivot arms between a folded down working position and an folded up storage position, wherein the jaws are configured to be positioned between the pivot arms and to lie opposite each other in the folded up storage position. The load handling tool comprises first and second locking means, the first locking means for locking the first jaw to the first pivot arm in the folded down working position and the second locking means for locking the second jaw to the second pivot arm in the folded down working position.

The load handling tool of the present invention can be brought into a compact condition by moving the jaw into the upwardly folded storage position, and the load handling tool can be held in this compact condition under the action of the actuating means acting on the pivot arm. A collapsible load handling tool of this type is adapted for use with a collapsible knuckle boom crane of the type described above, wherein the load handling tool with the bucket jaws in the folded up storage position may remain attached to the outer end of the outer boom as the outer boom is moved between the working position and the rest position, as explained in more close detail in the description below.

Further features of the load handling tool according to the invention will be apparent from the description and the dependent claims below.

The invention also relates to a hydraulic crane having the following features:

a hydraulic crane, comprising:

-a crane base;

-a column rotatably mounted to the crane base so as to be rotatable relative to the crane base about a vertical axis of rotation;

-a raisable and lowerable first crane boom hingedly connected to the column so as to be pivotable relative to the column about a horizontal axis of rotation; and the number of the first and second groups,

a second raisable and lowerable crane jib, which is connected in an articulated manner to the first crane jib so as to be pivotable relative to the first crane jib about a horizontal axis of rotation,

characterised in that the crane comprises a load handling tool according to the invention mounted to the outer end of the second crane boom.

Further advantageous features of the hydraulic crane according to the invention will be apparent from the description and the dependent claims below.

Drawings

The following is a detailed description of embodiments of the invention, which is cited as examples with reference to the accompanying drawings. In the drawings:

fig. 1 is a perspective view of a load handling tool according to a first embodiment of the invention, as can be seen, with the bucket jaws of the load handling tool locked in a folded down working position,

fig. 2 is a side view of the load handling tool of fig. 1, with the bucket jaws locked in a folded down working position,

fig. 3-5 are partial views of the load handling tool of fig. 1, with the bucket jaws locked in the folded down working position,

fig. 6 is a perspective view of the load handling tool of fig. 1, as seen, with the bucket jaws unlocked in the folded down working position,

fig. 7 is a partial view of the load handling tool of fig. 1, with the bucket jaws unlocked in the folded down working position,

fig. 8 is a perspective view of the load handling tool of fig. 1, as seen, with the bucket jaws in the upwardly folded storage position,

fig. 9 is a side view of the load handling tool of fig. 1, with the bucket jaws in the upwardly folded storage position,

fig. 10 is a partial view of the load handling tool of fig. 1, with the bucket jaws in the upwardly folded storage position,

figure 11 is a front view of a hydraulic crane provided with a load handling tool of the type shown in figures 1-10,

fig. 12 is a front view of the hydraulic crane of fig. 11, as seen, in a compact park position,

figure 13 is a plan view from above of the hydraulic crane of figure 11 in a stand-off position,

figure 14 is a side view of the hydraulic crane of figure 11 in a stand-off position,

figure 15 is a partial view of the hydraulic crane of figure 11 in a stand-off position,

figures 16 and 17 are perspective views of a retaining and locking mechanism included in the hydraulic crane of figure 11,

fig. 18a-18h are front views of the hydraulic crane of fig. 11, as seen, in different stages during movement of the crane from a rest position to an upright working position,

figure 19 is a partial view of the hydraulic crane in the position shown in figure 18c,

figures 20-22 are partial views of the hydraulic crane in the position shown in figure 18d,

fig. 23 and 24 are partial views of the hydraulic crane in the position shown in fig. 18e, and,

fig. 25 is a perspective view of a load handling tool according to a second embodiment of the invention, as seen with the bucket jaws in the upwardly folded storage position.

Detailed Description

A load handling tool 1 according to an embodiment of the invention is shown in fig. 1-10. As shown in fig. 11, the load handling tool 1 is to be attached to a crane boom. In the illustrated example, the load handling tool 1 is designed as a clamshell with an open shell.

The load handling tool 1 comprises a carrier head 2 and a rotator 3 mounted to the carrier head, wherein the carrier head 2 is configured to be connected to a crane boom via the rotator 3. The load handling tool 1 can be rotated relative to the crane boom by means of a swivel 3. The load handling tool 1 further comprises first and

second jaws

10, 30 carried by the carrier head 2 and positioned opposite each other. The first jaw 10 is pivotably connected to the carrier head 2 via a first pivot arm 11, and the second jaw 30 is pivotably connected to the carrier head 2 via a second pivot arm 31, allowing the

jaws

10, 30 to pivot towards each other in order to grip a load, and away from each other in order to release the gripped load. Each

jaw

10, 30 has a

leading edge

12, 32, wherein the leading edge 12 of the first jaw 10 faces the leading edge 32 of the second jaw 30.

Each

pivot arm

11, 31 has a

first end

11a, 31a and an opposite

second end

11b, 31b, the

first end

11a, 31a facing the carrier head 2 and the

second end

11b, 31b facing the associated

jaw

10, 30, wherein each

pivot arm

11, 31 is pivotably connected at its

first end

11a, 31a to the carrier head 2. The first pivot arm 11 is pivotable relative to the carrier head 2 about a first pivot axis a1 (see fig. 2) and the second pivot arm 31 is pivotable relative to the carrier head 2 about a second pivot axis a2, wherein the second pivot axis a2 is positioned at a distance from the first pivot axis a1 and extends parallel to the first pivot axis a 1.

Each

pivot arm

11, 31 is hingedly connected at its

second end

11b, 31b to the associated

jaw

10, 30, allowing the jaw to pivot relative to the

pivot arm

11, 31 between a folded down working position (see fig. 1-7) and an folded up storage position (see fig. 8-10). The

jaw portions

10, 30 are configured to be positioned between the

pivot arms

11, 31 and to be placed in an upwardly folded storage position relative to each other, as shown in fig. 8 and 9.

The first jaw 10 is pivotable relative to the first pivot arm 11 about a third pivot axis A3 (see fig. 2), the third pivot axis A3 extending parallel to the first pivot axis a1 described above, wherein the distance between the first and third pivot axes a1, A3 is greater than the distance between the third pivot axis A3 and the leading edge 12 of the first jaw 10 to thereby allow the first jaw 10 to be received between the first and

second pivot arms

11, 31 when the first jaw 10 is in the fold-up storage position.

The second jaw 30 is pivotable relative to the second pivot arm 31 about a fourth pivot axis a4 (see fig. 2), the fourth pivot axis a4 extending parallel to the second pivot axis a2 described above, wherein the distance between the second and fourth pivot axes a2, a4 is greater than the distance between the fourth pivot axis a4 and the leading edge 32 of the second jaw 30 to thereby allow the second jaw 30 to be received between the first and

second pivot arms

11, 31 when the second jaw 30 is in the upwardly folded storage position.

In the illustrated embodiment, each

jaw

10, 30 has a closed

bottom surface

13, 33. However, one or more openings may be provided in the

bottom surface

13, 33 of one or both of the jaws.

The load handling tool 1 comprises a first locking device 14 and a second locking device 34, the first locking device 14 being used to lock the first jaw 10 to the first pivot arm 11 in the folded-down working position, and the second locking device 34 being used to lock the second jaw 30 to the second pivot arm 31 in the folded-down working position.

Furthermore, the load handling tool 1 comprises actuating means 4 for pivoting the

pivot arms

11, 31 and thus the

jaws

10, 30 relative to the carrier head 2. In the embodiment shown in fig. 1-10, the actuating device 4 is a hydraulic motor accommodated in the carrier head 2, for example of the type described in more compact detail in DE 202004013158U 1 or EP 1541771B 1. The actuating means 4 comprises two rotatably driven pivot shafts rotatably mounted to the carrier head 2, each pivot shaft having two opposite shaft ends projecting from the carrier head 2 on opposite sides of the carrier head 2. The first pivot arm 11 is non-rotatably fixed to the opposite shaft end 5 of a first one of the pivot shafts and the second pivot arm 31 is non-rotatably fixed to the opposite shaft end 6 of the other pivot shaft. As an alternative, the actuating means may comprise one or two hydraulic cylinders for pivoting the

pivot arms

11, 31 and thus the

jaw parts

10, 30 relative to the carrier head 2. Any other suitable type of actuation means may also be used to pivot the

pivot arms

11, 31 relative to the carrier head 2.

In fig. 25 a load handling tool 1 according to an alternative embodiment is shown. The load handling tool 1 comprises an actuating device 4' in the form of a hydraulic cylinder, which is arranged vertically in the carrier head 2 and is configured to act on the first and

second pivot arms

11, 31 via the linkage 6 in order to pivot the

pivot arms

11, 31 relative to the carrier head 2. As for the rest, the load handling tool 1 shown in fig. 25 corresponds to the load handling tool shown in fig. 1-10.

The first locking device 14 described above includes at least one locking member 15 that is movable between an unlocked position (see fig. 6-8), in which the first jaw 10 is free to pivot relative to the first pivot arm 11 between a folded-down working position and an folded-up storage position, and a locked position (see fig. 1, 3 and 4), in which the locking member 15 prevents the first jaw 10 from pivoting relative to the first pivot arm 11 from the folded-down working position toward the folded-up storage position. In the embodiment shown, the first locking means 14 comprises two such locking members 15 which are slidably mounted to a cross bar 16 on the first pivot arm 11 so as to be slidable along the cross bar 16 between a locked position and an unlocked position. In the illustrated example, each locking member 15 includes a shoulder 17a (see fig. 7), the shoulder 17a being configured to contact a corresponding shoulder 17b (see fig. 8) on the first jaw 10 when the locking member 15 is in the locked position, as shown in fig. 4, and thereby prevent the first jaw 10 from pivoting relative to the first pivot arm 11 toward the upwardly folded storage position. When the locking member 15 is in the unlocked position, as shown in fig. 7 and 8, the shoulder 17a on the locking member is no longer in contact with the corresponding shoulder 17b on the first jaw 10, and the first jaw is thereby allowed to pivot relative to the first pivot arm 11 between the folded down working position and the folded up storage position.

The second locking device 34 described above includes at least one locking member 35 that is movable between an unlocked position (see fig. 6 and 10), in which the second jaw 30 is free to pivot relative to the second pivot arm 31 between a folded-down working position and an folded-up storage position, and a locked position (see fig. 1), in which the locking member 35 prevents the second jaw 30 from pivoting relative to the second pivot arm 31 from the folded-down working position towards the folded-up storage position. In the embodiment shown, the second locking means 34 comprises two such locking members 35 which are slidably mounted to a cross bar 36 on the second pivot arm 31 so as to be slidable along the cross bar 36 between a locked position and an unlocked position. The locking member 35 of the second locking device 34 has the same configuration as the locking member 15 of the first locking device 14 and operates in the same manner as the locking member 15 of the first locking device 14.

In the embodiment shown, each locking

device

14, 34 comprises a

handle

18, 38, by means of which handle 18, 38 the locking

member

15, 35 of the locking device is movable between a locked position and an unlocked position. The

handle

18, 38 is connected to the associated locking

member

15, 35 via a

linkage

19, 39.

The first and second locking means 14, 34 may of course also be configured and operated in any other suitable manner. Each locking

device

14, 34 may for example comprise a hydraulically or electrically operated actuation unit for moving the locking

member

15, 35 between the locked and unlocked positions.

Each

jaw

10, 30 is provided with at least one stop member 20, 40 (see fig. 1, 5, 8 and 10) which is configured to contact a

corresponding stop member

21, 41 on the associated

pivot arm

11, 31 and thereby stop pivotal movement of the

jaw

10, 30 relative to the

pivot arm

21, 31 when the

jaw

10, 30 has been pivoted relative to the

pivot arm

11, 31 from the upwardly folded storage position to the downwardly folded working position. In the embodiment shown, each

jaw

10, 30 is provided with several

such stop members

20, 40 distributed along the jaw.

When the

jaw

10, 30 is to be moved from the folded-down working position to the folded-up storage position, the locking

member

15, 35 is first moved from the locking position to the unlocking position. With the leading

edges

12, 32 of the first and

second jaws

10, 30 in contact with each other, the load handling tool 1 is then lowered downwardly against the upwardly projecting object so that the object will push the

leading edges

12, 32 of the

jaws

10, 30 upwardly in a pivotal movement relative to the

pivot arms

11, 31 about the third and fourth pivot axes A3, a4 until the

leading edges

12, 32 assume a position above the horizontal plane across the third and fourth pivot axes A3, a4 and are thus directed upwardly. The final movement of the

jaws

10, 30 to the folded-up storage position is achieved by means of the actuating device 4 described above, which actuating device 4 pivots the

pivot arms

11, 31 towards each other and thereby pushes the

jaws

10, 30 towards each other, so that the jaws are forced to pivot further upwards relative to the

pivot arms

11, 31 in order to finally assume the folded-up storage position shown in fig. 8 and 9. The

jaws

10, 30 are then maintained in the folded-up storage position by the actuator 4, the actuator 4 holding the jaws clamped between the

pivot arms

11, 31 in the folded-up storage position. The load handling tool 1 may also be provided with suitable locking means for keeping the

bucket jaws

10, 30 locked in the upwardly folded storage position. As shown in fig. 18g and 18h, when the load handling tool 1 is to be used later, the

pivot arms

11, 31 are pivoted away from each other by means of the actuating device 4, in order to allow the

jaw portions

10, 30 to pivot downward relative to the

pivot arms

11, 31 under the effect of gravity.

According to an alternative embodiment (not shown), the load handling tool 1 is provided with a hydraulically or electrically operated actuation unit for pivoting the

bucket jaws

10, 30 relative to the

pivot arms

11, 31 between a folded-down working position and an folded-up storage position.

In fig. 11-24 a hydraulic crane 60 provided with a load handling tool 1 of the type described above is shown. The crane 60 is shown mounted on a frame 61, which frame 61 may be connected to the chassis of a truck, for example. The frame 61 is provided with adjustable support legs 62 for supporting the crane 60. The crane 60 includes:

a crane base 63 fixed to the frame 61;

a column 64 rotatably mounted to the crane base 63 so as to be rotatable with respect to the crane base about a substantially vertical rotation axis a5 by means of an actuating device (not shown);

a first, raisable and lowerable crane boom 65, hereinafter named inner boom, which is hingedly connected to the column 64 in such a way that it can pivot relative to the column about a substantially horizontal axis of rotation a 6;

a first hydraulic cylinder 66 for raising and lowering the inner boom 65 relative to the column 64;

a second, raisable and lowerable crane jib 67, hereinafter named outer jib, which is hingedly connected to the inner jib 65 in such a way that it can pivot relative to the inner jib about a substantially horizontal axis of rotation a 7; and the number of the first and second groups,

a second hydraulic cylinder 68 for raising and lowering the outer boom 67 relative to the inner boom 65.

The outer boom 67 is telescopically extendable, which enables adjustment of its extension length. The outer boom 67 comprises a base section 67a and several telescopic crane boom sections 67b, the outer boom 67 being hingedly connected to the inner boom 65 by means of the base section 67a, the telescopic crane boom sections being carried by the base section 67a and being displaceable in the longitudinal direction of the base section by means of hydraulic cylinders 69 for adjusting the extension length of the outer boom 67.

The illustrated crane 60 is a collapsible knuckle boom crane in which the inner boom 65 and outer boom 67 of the crane are collapsible into a compact parked position when the crane is to be transported or stored, as shown in fig. 12-14. When the inner boom 65 and the outer boom 67 are to be folded from the upright working position shown in fig. 11 into the parking position, the telescopic crane boom section 67b of the outer boom 67 is first retracted into the base section 67a of the outer boom, and then the outer boom 67 is folded down towards the inner boom 65 to assume a position substantially parallel to the inner boom, as shown in fig. 18 b. The inner boom 65 is then folded down together with the outer boom 67 towards the frame 61 from the intermediate position shown in fig. 18b to the final rest position shown in fig. 12. The inner boom 65 and the outer boom 67 move in an opposing manner as the inner boom 65 and the outer boom 67 move from the rest position to the upright work position.

The load handling tool 1 is mounted to the outer end of the outer boom 67. To prevent the load handling tool 1 from crashing into the column 64 when the inner and

outer booms

65, 67 are moved from the upright working position to the rest position or vice versa, the

jaws

10, 30 of the load handling tool 1 must be in the upwardly folded storage position and arranged in a suitably fixed position relative to the outer boom 67. To do this, the crane 60 comprises a holding and locking mechanism 70 (see fig. 15-17) for locking the load handling tool 1 with the first and

second jaws

10, 30 in the upwardly folded storage position and with the load handling tool 1 in a given fixed position relative to the outer boom 67 and at the side of the outer boom 67.

In the illustrated embodiment, the retention and locking mechanism 70 includes:

a first coupling member 72a (see fig. 16, 17 and 24) fixed to the outer boom 67 and configured for engagement with a corresponding second coupling member 22 (see fig. 11 and 24) on the first jaw 10;

a third coupling member 72b (see fig. 16, 17 and 24) fixed to the outer boom 67 and configured for engagement with a corresponding fourth coupling member 42 (see fig. 11 and 24) on the second jaw 30; and the number of the first and second groups,

a locking member 73 (see fig. 15-17 and 19) movable between a locked position (see fig. 15) in which the locking member 73 prevents the first and

third coupling members

72a, 72b from disengaging from the corresponding

coupling members

22, 42 on the

jaw

10, 30, and an unlocked position (see fig. 19) in which the locking member 73 allows the first coupling member 72a to disengage from the second coupling member 22 and the third coupling member 72b to disengage from the fourth coupling member 42.

In the illustrated example, the first and

third coupling members

72a, 72b have the form of hooks, whereas the second coupling member 22 has the form of a recess in the first jaw 10, and the fourth coupling member 42 has the form of a recess in the second jaw 30. In this case, first coupling member 72a may be inserted into second coupling member 22, and third coupling member 72b may be inserted into fourth coupling member 42.

The holding and locking mechanism 70 further comprises a base structure 74 fixed to the base section 67a of the outer boom 67, wherein the first and

third coupling members

72a, 72b are fixed to the base structure 74 and protrude from the base structure 74. In the embodiment shown, the locking member 73 of the retention and locking mechanism 70 has the form of a lever and is pivotally mounted to the base structure 74 by a joint 75 so as to be pivotable relative to the base structure 74 about the joint 75 between its locking position and its unlocking position. The locking member 73 is provided with a protruding locking element 76 (see fig. 16 and 19), the locking element 76 being configured to engage with the second or

fourth coupling member

22, 42 when the locking member 73 is in its locked position. In the illustrated example, when the third coupling member 72b is engaged with the fourth coupling member 42 and the locking member 73 is in its locked position, the locking element 76 is positioned proximate to the third coupling member 72b and is configured to be received in the fourth coupling member 42 directly behind the third coupling member 72b to thereby prevent the fourth coupling member 42 from slipping relative to the third coupling member 72b to a position in which the third coupling member 72b can be moved out of the fourth coupling member 42. The locking element 76 is located on a first side of the above-mentioned joint 75, wherein the center of gravity of the locking member 73 is located on the opposite side of this joint 75, in order to allow the locking member 73 to be automatically moved between its locking position and its unlocking position by a rotational movement around the joint 75 under the influence of gravity and according to the orientation in space of the locking member 73. Thus, the locking member 73 will act as a rocker arm and assume its locked position or its unlocked position depending on the orientation in the space of the outer boom 67 and the base structure 74. When the outer boom 67 and the base structure 74 have an orientation in space such that the locking element 76 on the locking member 73 points upwards, the locking member 73 will assume its locking position, in which the locking element 76 is forced outwards away from the outer boom 67, as shown in fig. 15. When the outer boom 67 and the base structure 74 have an orientation in space such that the locking element 76 on the locking member 73 points downwards (see fig. 19), the locking member 73 will assume its unlocked position, in which the locking element 76 is forced inwards towards the outer boom 67, as shown in fig. 19.

In the illustrated embodiment, a hook-shaped guide member 77 (see fig. 14-17 and 21) is provided on the base structure 74, wherein this guide member 77 is configured for contact with the load handling tool 1 in order to ensure that the load handling tool 1 will be correctly positioned relative to the base structure 74, wherein the second and

fourth coupling members

22, 42 on the

jaw portions

10, 30 of the load handling tool 1 are positioned in front of the first and

third coupling members

72a, 72b on the base structure 74. As shown in fig. 14 and 15, the hook-shaped guide member 77 is configured to engage with the portion 11a of the first pivot arm 11.

When the crane 60 is in the stand-by position, as shown in fig. 12-14, the holding and locking mechanism 70 holds the load handling tool 1 fixed to the outer boom 67 in a position above the outer boom and at the sides of the column 64 and the inner boom 65, with the hook-shaped guide member 77 engaged with the first pivot arm 11, the first and

third coupling members

72a, 72b on the base structure 74 engaged with the corresponding

coupling members

22, 42 on the

bucket jaws

10, 30, and the locking member 73 in its locked position, with the locking element 76 received in the fourth coupling member 42. When the crane 60 is to be moved into the erected working position, the inner boom 65 is first pivoted relative to the column 64 and raised upwards from the position shown in fig. 12 to the position shown in fig. 18a and further on to the position shown in fig. 18 b. When the outer boom 67 and the load handling tool 1 are pivoted together with the inner boom 65 from the position shown in fig. 12 to the position shown in fig. 18b, the locking member 73 is still in its locked position and thereby prevents the load handling tool 1 from moving relative to the outer boom 67. In the next step, the outer boom is pivoted relative to the inner boom 65 and raised upwards from the position shown in fig. 18b to the position shown in fig. 18c and further to the position shown in fig. 18d, wherein the locking member 73 is automatically pivoted under the influence of gravity from its locked position to its unlocked position, which means that the locking element 76 no longer prevents the second and

fourth coupling members

22, 42 on the

bucket jaws

10, 30 from being released from the corresponding first and

third coupling members

72a, 72b on the base structure 74. With the outer boom 67 in the position shown in fig. 18d, the second and

fourth coupling members

22, 42 on the grappling

jaws

10, 30 are released from the corresponding first and

third coupling members

72a, 72b on the base structure 74 by a short extension of the outer boom 67. Thereafter, by rotation of the load handling tool 1 by means of the rotator 3 from the position shown in fig. 18d and 20 to the position shown in fig. 18e and 23, the load handling tool 1 can be released from the hook-shaped guide members 77 on the base structure 74. As shown in fig. 18g and 18h, the load handling tool 1 is now freely suspended at the outer end of the outer boom 67, and by pivoting the

pivot arms

11, 31 outwardly away from each other, the

jaws

10, 30 may be allowed to pivot downwardly under gravity from the upwardly folded storage position to the downwardly folded working position. Finally, the locking

members

15, 35 of the first and second locking means 14, 34 are moved from the unlocked position to the locked position in order to lock the

jaw

10, 30 to the

pivot arm

11, 31 in the folded-down working position.

By performing the steps shown in fig. 18a-18h in relative order when the

bucket jaws

10, 30 have been pivoted from the folded-down working position to the folded-up storage position, the load handling tool 1 can be secured to the outer boom 67 by means of the holding and locking mechanism 70 and the mobile-to-rest position crane 60.

The retaining and locking mechanism 70 may of course also have any other suitable configuration than the one shown in the figures.

The invention is of course not in any way restricted to the embodiments described above. On the contrary, many possibilities to modifications thereof will be apparent to a person with ordinary skill in the art without departing from the basic idea of the invention such as defined in the appended claims.

Claims

1. A load handling tool attached to a crane boom, the load handling tool (1) comprising:

-a carrier head (2) configured for connection to a crane boom;

-first and second jaws (10, 30) positioned relative to each other, the first jaw (10) being pivotably connected to the carrier head (2) via a first pivot arm (11) and the second jaw (30) being pivotably connected to the carrier head (2) via a second pivot arm (31) allowing the jaws (10, 30) to pivot towards each other for gripping a load and away from each other for releasing the gripped load, each pivot arm (11, 31) having a first end (11 a, 31 a) facing the carrier head (2) and an opposite second end (11 b, 31 b), wherein each pivot arm (11, 31) is pivotably connected to the carrier head (2) at its first end (11 a, 31 a); and the number of the first and second groups,

-actuating means (4) for pivoting the pivot arms (11, 31) and thereby the jaws (10, 30) relative to the carrier head (2),

the method is characterized in that:

-each pivot arm (11, 31) is hingedly connected at its second end (11 b, 31 b) to an associated jaw (10, 30) allowing the jaws to pivot relative to the pivot arms (11, 31) between a folded-down working position and an folded-up storage position, wherein the jaws (10, 30) are configured to be positioned between the pivot arms (11, 31) and to lie opposite each other in the folded-up storage position; and the number of the first and second groups,

-the load handling tool (1) comprises a first locking device (14) and a second locking device (34), the first locking device (14) being used to lock the first jaw (10) to the first pivot arm (11) in the folded-down working position, the second locking device (34) being used to lock the second jaw (30) to the second pivot arm (31) in the folded-down working position.

2. The load handling tool of claim 1, wherein:

-the first pivot arm (11) is pivotable relative to the carrier head (2) about a first pivot axis (a 1);

-the second pivot arm (31) is pivotable relative to the carrier head (2) about a second pivot axis (a 2), the second pivot axis (a 2) extending parallel to the first pivot axis (a 1);

-the first jaw (10) is pivotable relative to the first pivot arm (11) about a third pivot axis (A3), the third pivot axis (A3) extending parallel to the first pivot axis (a 1), wherein the distance between the first and third pivot axes (a 1, A3) is larger than the distance between the third pivot axis (A3) and the leading edge (12) of the first jaw (10);

-the second jaw (30) is pivotable relative to the second pivot arm (31) about a fourth pivot axis (a 4), the fourth pivot axis (a 4) extending parallel to the second pivot axis (a 2), wherein the distance between the second and fourth pivot axes (a 2, a 4) is larger than the distance between the fourth pivot axis (a 4) and the leading edge (32) of the second jaw (30).

3. The load handling tool according to claim 2, wherein the first pivot axis (A1) is positioned at a distance from the second pivot axis (A2).

4. The load handling tool of any of claims 1-3, wherein:

-the first locking device (14) comprises at least one locking member (15) movable between an unlocked position, in which the first jaw (10) is free to pivot relative to the first pivot arm (11) between a folded-down working position and an folded-up storage position, and a locked position, in which the locking member (15) prevents the first jaw (10) from pivoting relative to the first pivot arm (11) from the folded-down working position towards the folded-up storage position; and the number of the first and second groups,

-the second locking device (34) comprises at least one locking member (35) movable between an unlocked position, in which the second jaw (30) is free to pivot relative to the second pivot arm (31) between a folded-down working position and an folded-up storage position, and a locked position, in which the locking member (35) prevents the second jaw (30) from pivoting relative to the second pivot arm (31) from the folded-down working position towards the folded-up storage position.

5. The load handling tool of claim 4, wherein:

-said first locking means (14) comprises a handle (18), by means of which handle (18) said at least one locking member (15) of said first locking means is movable between a locked position and an unlocked position; and the number of the first and second groups,

-said second locking means (34) comprises a handle (38), by means of which handle (38) said at least one locking member (35) of said second locking means is movable between a locked position and an unlocked position.

6. The load handling tool of claim 4, wherein:

-said locking member (15) of said first locking means (14) is slidably mounted to a lever (16) on said first pivot arm (11) so as to be slidable along this lever (16) between said locking position and said unlocking position; and the number of the first and second groups,

-said locking member (35) of said second locking means (34) is slidably mounted to a lever (36) on said second pivot arm (31) so as to be slidable along this lever (36) between a locked position and an unlocked position.

7. The load handling tool of any of claims 1-3, wherein:

-the first jaw (10) is provided with at least one stop member (20), which at least one stop member (20) is configured to contact a corresponding stop member (21) on the first pivot arm (11) and thereby stop the pivotal movement of the first jaw (10) relative to the first pivot arm (11) when the first jaw (10) has been pivoted relative to the first pivot arm (11) from the folded-up storage position to the folded-down working position; and the number of the first and second groups,

-the second jaw (30) is provided with at least one stop member (40), which at least one stop member (40) is configured to contact a corresponding stop member (41) on the second pivot arm (31) and thereby stop the pivotal movement of the second jaw (30) relative to the second pivot arm (31) when the second jaw (30) has been pivoted relative to the second pivot arm (31) from the upwardly folded storage position to the downwardly folded working position.

8. A load handling tool according to any of claims 1-3, characterized in that the load handling tool (1) is a clamshell with an open shell.

9. A hydraulic crane, comprising:

-a crane base (63);

-a column (64) rotatably mounted to the crane base (63) so as to be rotatable with respect to the crane base about a vertical axis of rotation (a 5);

-a raisable and lowerable first crane boom (65) which is hingedly connected to the column (64) so as to be pivotable relative to the column about a horizontal axis of rotation (a 6); and the number of the first and second groups,

-a second, raisable and lowerable crane jib (67) which is hingedly connected to the first crane jib (65) so as to be pivotable relative to the first crane jib about a horizontal axis of rotation (A7),

-the crane (60) comprising a load handling tool (1) according to any of claims 1-8 mounted to an outer end of the second crane boom (67).

10. Hydraulic crane according to claim 9, characterized in that the crane (60) comprises a holding and locking mechanism (70), which holding and locking mechanism (70) is used to lock the load handling tool (1) to the second crane boom (67) with the first and second bucket jaws (10, 30) in the folded-up storage position and with the load handling tool (1) in a given fixed position relative to the second crane boom (67) and at the side of the second crane boom (67).

11. The hydraulic crane according to claim 10, characterized in that the retaining and locking mechanism (70) comprises:

-a first coupling member (72 a) fixed to the second crane boom (67) and configured for engagement with a corresponding second coupling member (22) on the first jaw (10);

-a third coupling member (72 b) fixed to the second crane boom (67) and configured for engagement with a corresponding fourth coupling member (42) on the second bucket jaw (30); and the number of the first and second groups,

-a locking member (73) movable between a locked position, in which said locking member (73) prevents the disengagement of said first coupling member (72 a) from said second coupling member (22) and prevents the disengagement of said third coupling member (72 b) from said fourth coupling member (42), and an unlocked position, in which said locking member (73) allows the disengagement of said first coupling member (72 a) from said second coupling member (22) and the disengagement of said third coupling member (72 b) from said fourth coupling member (42).

12. The hydraulic crane of claim 11, wherein:

-the first coupling member (72 a) has the form of a hook and the second coupling member (22) has the form of a recess, wherein the first coupling member (72 a) is insertable into the second coupling member (22); and the number of the first and second groups,

-the third coupling member (72 b) has the form of a hook and the fourth coupling member (42) has the form of a recess, wherein the third coupling member (72 b) is insertable into the fourth coupling member (42).

13. The hydraulic crane of claim 12, wherein:

-the holding and locking mechanism (70) comprises a base structure (74) fixed to the second crane boom (67), wherein first and third coupling members (72 a, 72 b) are fixed to the base structure (74); and the number of the first and second groups,

-the locking member (73) of the holding and locking mechanism (70) has the form of a lever and is pivotally mounted to the base structure (74) by means of a joint (75) so as to be pivotable relative to the base structure (74) about the joint (75) between its locking position and its unlocking position.

14. The hydraulic crane of claim 13, wherein:

-the locking member (73) of the retention and locking mechanism (70) is provided with a protruding locking element (76), the locking element (76) being configured to engage with the second or fourth coupling member (22, 42) when the locking member (73) is in its locked position; and the number of the first and second groups,

-the locking element (76) is located on a first side of the joint (75), wherein the centre of gravity of the locking member (73) is located on the opposite side of the joint (75) in order to allow the locking member (73) to move under gravity between its locked position and its unlocked position depending on the orientation in space of the second crane boom (67).

15. The hydraulic crane according to claim 13 or 14, characterized in that:

-the second crane boom (67) is telescopically extendable such that its extension length can be adjusted, wherein the second crane boom (67) comprises a base section (67 a) and one or more telescopic crane boom sections (67 b) carried by the base section (67 a), the second crane boom (67) being hingedly connected to the first crane boom (65) by the base section (67 a); and the number of the first and second groups,

-the base structure (74) of the holding and locking mechanism (70) is fixed to the base section (67 a) of the second crane jib (67).