Hoisting Device

TECHNICAL FIELD

[0001] The invention is related to an ultra large crane, comprising at least one mast, a base supporting the mast at its lower end and guy wire gear between the top end of the mast and the base, said mast comprising mast sections which are aligned according to the longitudinal direction of the mast, which are releasably connected to each other end to end, which have an extended state defined by a nominal width, and which mast sections after disconnection from each other are transferrable to a retracted state in which said mast sections have a reduced width and are transportable within a predetermined space, such as in an ISO-container, wherein said mast sections comprise girder members which extend in said longitudinal direction and truss members which extend obliquely between, and are connected to, the girder members.

BACKGROUND ART

[0002] A mast section for such an ultra large crane is disclosed in NL-C-1035078. This prior art mast section is composed of two halves which are releasably connected to each other. The mast section halves each consist of a girder member and truss halves. The truss halves are to be interconnected whereby a mast section with a relatively large width is obtained. A relatively wide mast section provides a high moment of inertia, which is beneficial for withstanding high compressive forces and for avoiding buckling phenomena. After disassembling the mast section halves, they can be nested into each other. Thus, a relatively narrow set is obtained the limited dimensions of which make the transport thereof possible in a convenient way by road, e.g. in an ISO-container. The mobility of the mast sections thus obtained is of the utmost importance, as otherwise the ultra large crane would not readily be transportable and would not be fit for universal use.

[0003] Although the mobility as obtained by the width reduction of the mast sections is a step forward, the amount of work involved in assembling and

disassembling each mast section into two halves is cumbersome an labour-intensive. The number of connections to be made up is rather high, as each separate truss member and transverse member is split up and is therefore to be coupled/uncoupled. Furthermore, the halves of a mast section are completely separated from each other after disassembly, which makes it rather difficult to handle them and to ascertain the proper pairing of the halves.

[0004] It would be desirable to reduce assembly and/or disassembly times for an ultra large crane, and/or with less costs and labour. It may also be desirable to provide an ultra large crane which has a greater reliability and/or which poses less risk with respect to malfunction.

SUMMARY OF INVENTION

[0005] Therefore, according to a first aspect, there is provided a mast section according to the preamble of claim 1, characterized in that a truss member of the mast section is connected to one of the girder members by means of a hinge connection and to another of the girder members by means of a slide connection, in that another truss member of said at least one mast section is connected to said another of the girder members by means of another hinge connection and to said one of the girder members by means of another slide connection, in that said truss member and said another truss member cross each other according to a crossing angle and at the location of their crossing point are connected to each other through a scissor hinge connection, and in that the slide connections comprise a releasable nominal locking mechanism, wherein in the extended state of said at least one mast section the crossing angle of said one truss member and said another truss member is relatively large and said one truss member and said another truss member are locked at a nominal lock position of the corresponding slide connection, and wherein in the retracted state of the mast section the crossing angle of said one truss member and said another truss member is relatively small and said truss member and said another truss member are unlocked with respect to the nominal lock position.

[0006] The term "crossing angle" is associated herein with an angle that extends between the corresponding truss members with respect to the scissor hinge connection as common vertex, and which opens towards the (positive or negative) longitudinal direction along which the girder members extend.

[0007] In the crane according to the invention, mast sections are applied which make it possible to change the width of the mast section, as is the case in the prior art mast sections. However, the mast section is not completely divided into two separate halves, but remains a unitary construction. Thereby, it is made easier to change the width of the mast section by merely moving the girder members towards or away from each other. The truss members will automatically adjust to the required position.

Furthermore, only the locking mechanisms need to be activated/deactivated as required, which entails only little time and labour. Moreover, due to the unitary construction no pairing problems will occur.

[0008] For ease of handling of the mast section in retracted state, it is possible that said one truss member and said another truss member are locked at a transport lock position of the corresponding slide connection through a transport locking mechanism, which transport lock position is at a distance from the nominal lock position thereof.

[0009] The truss member and the other truss member constitute a pair of truss members. With the aim of further improving the stability of the mast section, it is preferred that the mast section comprises at least two pairs of truss members, the hinge connections of one pair of truss members being located at one end of the girder members and the hinge connections of another pair of truss members being located at the opposite end of the girder members. Such mast section with multiple pairs of truss members can be carried out in various ways. For instance, the pairs may positioned at a relatively large distance from each other, seen in longitudinal direction of the mast section, in such a way that trusses of adjacent pairs will not overlap each other.

[0010] Preference is however given to an embodiment wherein a truss member of one pair of truss members and a truss member of another pair of truss members freely cross each other, the slide connections of said freely crossing truss members adjoining each other end to end in the longitudinal direction of the mast section. Thereby, a continuous trajectory of directly adjacent truss members is obtained which in the extended state provide optimal strength and stiffness to the mast section.

[0011] According to yet another embodiment the mast section may comprise at least three pairs of truss members, in which case the hinge connections of at least one pair of truss members are located at a distance from both ends of the girder members.

[0012] The truss members themselves may be formed in several ways as well. Preferably, a truss member comprises two spaced apart parallel truss bars. In this case, one of the trusses is located next to one side of the mast section and the other truss is located next to the opposite side of the mast section. In this embodiment, the truss bars of at least one truss member may be spaced apart at a relatively large distance and the truss bars of at least one other truss member may be spaced apart at a relatively small distance in such a way that the truss bars which are spaced apart at a relatively small distance are accommodated between the truss bars which are spaced apart at a relatively large distance. For further improving the strength and stability of the mast section, truss bars which are spaced apart at a relatively small distance may be interconnected by bracing bars. Preferably, the mast section may comprise four parallel girders, defining a square or rectangular cross section.

[0013] The crane may comprise one such mast which is composed of mast sections as described before. In an alternative embodiment, the crane may comprise two such masts, said masts being connected to each other at their top ends and being supported on the base at their lower ends at a distance from each other.

[0014] According to a second aspect, and in accordance with the advantages and effects described herein above, there is provided a mast section for the mast of an ultra large crane as described above, which mast section has a extended state defined by a nominal width and a retracted state with a reduced width so as to be transportable within a predetermined space, such as in an ISO-container, comprising parallel girder members and truss members which extend obliquely between, and are connected to, the girder members. This mast section is characterized in that a truss member is connected to one of the girder members by means of a hinge connection and to another of the girder members by means of a slide connection, in that another truss member is connected to said another of the girder members by means of another hinge connection and to said one of the girder members by means of another slide connection, in that said truss member and said another truss member cross each other according to a crossing angle and at the location of their crossing point are connected to each other through a central hinge connection, and in that the slide connections comprise a releasable nominal locking mechanism, wherein in the extended state of said mast section the crossing angle of said one truss member and said another truss member is relatively large and said one truss member and said another truss member are locked at a nominal lock position of the corresponding slide connection, and wherein in the retracted state of the mast section the crossing angle of said one truss member and said another truss member is relatively small and said truss member and said another truss member are unlocked with respect to the nominal lock position. [0015] According to a third aspect, and in accordance with the advantages and effects described herein above, there is provided a method for of providing an ultra large crane in accordance with the first aspect, the method comprising:

- providing a series of mast sections in accordance with the second aspect;

- transferring the mast sections into the retracted state with reduced width;

- transporting the mast sections in said retracted state to a predetermined location;

- providing a base and guy wire gear at the predetermined location;

- after arrival at the predetermined location, transferring the mast sections into the extended state by:

- enlarging the distance between the girder members of each mast section and consequently increasing the crossing angle of the associated truss members thereof,

- after obtaining the nominal width of the mast sections, activating the nominal locking mechanisms of the associated slide connections,

- forming the mast by connecting the mast sections in extended state end to end to each other, and

- placing the lower end of the mast on the base and applying the guy wire gear between the top of the mast and the base.

[0016] Alternative aspects and embodiments of the invention (with advantages and effects described herein above) are defined by clauses that are presented herein further below, and which may be combined with any or all of the claims below and/or be subject of a divisional application.

BRIEF DESCRIPTION OF DRAWINGS

[0017] Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts. In the drawings, like numerals designate like elements. Furthermore, multiple instances of an element may each include separate letters appended to the element number. For example two instances of a mast section "20" may be labelled as "20i" and "20j", or two instances of girder members "22" may be labelled as "22a" and "22b". In those cases, the element labels may be used without an appended letter (e.g. "20") to generally refer to generic instances of the element, while the element label will include an appended letter (e.g. "20a") to refer to a specific instance of the element.

[0018] Figure 1 shows a side view of an ultra large crane according to an embodiment;

[0019] Figure 2 shows a top view of the crane from Figure 1, and

[0020] Figures 3-5 show perspective views of a mast section for the crane of Figure 1 in various states.

[0021] The figures are meant for illustrative purposes only, and do not serve as restriction of the scope or the protection as laid down by the claims.

DESCRIPTION OF EMBODIMENTS

[0022] Figures 1 and 2 schematically show side and top views of an exemplary embodiment of an ultra large crane 10. The crane 10 comprises two masts 12a, 12b, which are connected to each other at their top ends. The lower ends of the masts are at a distance from each other and are supported on the base 16. This base 16 is known per se and provides the possibility to rotate the masts around a vertical crane axis. The interconnected top ends of the masts 12 are held upright with respect to the base 16 by means of the guy wire gear 18, which is connected between said top ends and the base 16.

[0023] Both masts 12 consist of mast sections 20i, 20j, 20k, which are

interconnected end to end along a longitudinal direction Z. These mast sections 20 each have two mutually parallel girder members 22, 23 and pairs of truss members 26, 27. The girder members 22, 23 are mutually spaced along a first transverse direction X.

[0024] Figures 3-5 show perspective views of a mast section 20 for the crane 10 of Figure 1 in various states. As is shown, the truss members 26, 27 of a truss member pair 42 cross each other and are connected to each other through a scissor hinge connection 34. In the embodiment shown, one end of a first truss member 26 of each pair of truss members 42 is connected through a first hinge connection 28 to a distal end 24 of a first girder member 22, while the other end of the first truss member 26 is connected to the second girder member 23 through a first slide connection 30.

Similarly, one end of a second truss member 27 of each pair of truss members 42 is connected through a second hinge connection 29 to a distal end 25 of the second girder member 23 while the other end of the second truss member 27 is connected to the first girder member 22 through a second slide connection 31.

[0025] Each slide connection 30, 31 cooperates or is provided with a nominal locking mechanism 32, 33. In the extended state of the mast section 20 shown in Figure 3, the nominal locking mechanisms 32, 33 are locked, and the truss members 26, 27 are firmly fixed with respect to the respective girder members 22, 23 with the slide connections 30, 31 locked at nominal lock positions Zn.

[0026] In the extended state of the mast section 20 as shown in Figure 3, a nominal distance ΔΧη is defined between the girder members 22, 23 in the first transverse direction X, yielding a corresponding nominal width of the mast section 20. Thus, a firm and stable mast section 20 in the extended state is obtained, with a high moment of inertia and the required properties concerning strength and stiffness.

[0027] In the embodiment shown, the truss members 26, 27 each consist of two parallel truss bars 38-39. Truss bars 38a, 39b of crossing truss members 27a, 27b cross each other as well. In this example, an inner pair of parallel truss bars 39b is spaced at a smaller mutual distance along the second transverse direction Y in comparison to an outer pair of parallel truss bars 38a, in such a way that the inner and outer parallel truss bars 38a, 39b cross each other freely. The inner pairs of parallel truss bars 39a, 39b are provided with bracing bars 40, which further increase the strength, stiffness and stability.

[0028] In the extended state, the mast section 20 is fit for use in the masts 12 of the crane 10. However, the dimensions of the mast section 20 in this state are too large for convenient transport, e.g. by road. It appears that the dimensions of the mast 20 section in the extended state grossly exceed the maximum allowable dimensions for road cargos. Also, it appears that mast section 20 in the extended state cannot be loaded in ISO-containers. For the purpose of still allowing the mast section 20 to be transported, it is transitioned into its retracted state with a reduced width, as will now be discussed with reference to the Figures 4 and 5.

[0029] First of all, the nominal locking mechanisms 32, 33 are released, whereby the truss members 26, 27 are able to slide along the slide connection 30, 31 (in this example predominantly along the longitudinal direction Z), so that the second girder member 23 (in this case the upper member) will be moved transversely towards the first girder member 22. The truss members 26, 27 of each member pair 42 rotate around their corresponding scissor hinge connection 34 with respect to each other, whereby a crossing angle a between these truss members 26, 27 is reduced (Figure 4) from a nominal crossing angle an in the extended state (Figure 3) to a reduced crossing angle ar in the retracted state (Figure 5). Finally, the retracted state as shown in Figure 5 is obtained, with a strongly reduced distance ΔΧΓ between the girder members 22, 23 in the first transverse direction X, and a corresponding reduced width of the mast section 20. In this retracted state, the slide connections 30, 31 of the truss members 26, 27 and the girder members 22, 23 can be locked through respective transport locking mechanisms 36. In this retracted state, the mast section 20 can be accommodated in an ISO-container fit for transport by road, sea etc.

[0030] In the retracted state of the mast section 20 shown in Figure 5, the further locking mechanisms 36 are locked, so that the truss members 26, 27 are firmly fixed with respect to the respective girder members 22, 23. Here, the slide connections 30, 31 are locked at reduced lock positions Zr, which are displaced along the longitudinal direction Z over non-zero distances ΔΖ with respect to the associated nominal lock position Zn.

[0031] A set of clauses is presented directly below, which present alternative definitions of aspects and embodiments of the invention, and which may serve to define further embodiments in accordance with the claims presented further below, or be subject of a divisional application.

CLAUSES

cl . An ultra large crane (10), comprising at least one mast (12), a base (16) supporting the mast at its lower end and guy wire gear (18) between a top end of the mast and the base, said mast comprising mast sections (20) which are aligned according to a longitudinal direction (Z) of the mast and which are releasably connected to each other end to end, and which have an extended state defined by a nominal width (ΔΧη), which mast sections after disconnection from each other are transferrable to a retracted state in which said mast sections have a reduced width (ΔΧΓ) and are transportable within a predetermined space, such as in an ISO-container, wherein at least one mast section comprises girder members (22, 23) which extend in said longitudinal direction and truss members (26, 27) which extend obliquely between and are connected to the girder members, wherein a truss member (26) of said at least one mast section is connected to one of the girder members (22) by means of a hinge connection (28) and to another of the girder members (23) by means of a slide connection (30), wherein another truss member (27) of said at least one mast section is connected to said another of the girder members (23) by means of another hinge connection (29) and to said one of the girder members (22) by means of another slide connection (31), wherein said truss member (26) and said another truss member (27) cross each other according to a crossing angle (a) associated with the longitudinal direction, and at the location of their crossing point are connected to each other through a scissor hinge connection (34), wherein the slide connections (30, 31) comprise a releasable nominal locking mechanism (32), wherein in the extended state of said at least one mast section the crossing angle of said one truss member and said another truss member is relatively large and said one truss member and said another truss member are locked at a nominal lock position of the corresponding slide connection, and wherein in the retracted state of the mast section, the crossing angle of said one truss member and said another truss member is relatively small and said truss member and said another truss member are unlocked with respect to the nominal lock position. c2. The crane (10) according to clause 1, wherein in the retracted state said one truss member (26) and said another truss member (27) are locked at a transport lock position of the corresponding slide connection (30, 31), e.g. by means of a releasable transport lock mechanism (36), which transport lock position is at a distance from the nominal lock position thereof. c3. The crane (10) according to clause cl or c2, wherein the truss member (26) and the another truss member (27) constitute a pair (42) of truss members, wherein the mast section (20) comprises at least two pairs (42a, 42b) of truss members, the hinge connections (28a, 29a) of one pair of truss members (42a) being located at one end (24a, 25a) of the girder members (22, 23) and the hinge connections (28b, 29b) of another pair (42b) of truss members being located at the opposite end (24b, 25b) of the girder members (22, 23). c4. The crane (10) according to clause c3, wherein a truss member (26a) of one pair (42a) of truss members and a truss member (26b) of another pair (42b) of truss members freely cross each other, the slide connections (30a, 30b) of said freely crossing truss members adjoining each other end to end in the longitudinal direction (Z) of the mast section (20). c5. The crane (10) according to clause c3 or c4, wherein the mast section (20) comprises at least three pairs of truss members (42a-42c), and the hinge connections (28, 29) of at least one pair of truss members are located at longitudinal distances from both ends (24, 25) of the girder members (22, 23). c6. The crane (10) according to any one of clauses cl-c5, wherein a truss member (26, 27) comprises two parallel truss bars (38, 39) that are spaced apart in a second transverse direction (Y). c7. The crane (10) according to clause c6, wherein the truss bars (38) of at least one truss member (26, 27) are spaced apart at a relatively large distance and the truss bars (39) of at least one other truss member (27, 26) are spaced apart at a relatively small distance, and wherein the truss bars which are spaced apart at a relatively small distance are accommodated between the truss bars which are spaced apart at a relatively large distance. c8. The crane (10) according to clause c7, wherein the truss bars (39) which are spaced apart at a relatively small distance are interconnected by bracing bars (40). c9. The crane (10) according to any one of clauses cl-c8, wherein the mast section (20) comprises four parallel girders, defining a square or rectangular cross section. clO. The crane (10) according to any one of clauses cl-c9, comprising two masts (12a, 12b), said masts being connected to each other at their top ends and being supported on the base (16) at their lower ends at a distance from each other. cl 1. A mast section (20) for the mast (12) of an ultra large crane (10) according to any one of clauses cl-clO, which mast section has an extended state defined by a nominal width (ΔΧη) and a retracted state with a reduced width (ΔΧΓ) SO as to be transportable within a predetermined space, such as in an ISO-container, comprising parallel girder members (22, 23) and truss members (26, 27) which extend obliquely between, and are connected to, the girder members, wherein a truss member (26) is connected to one of the girder members (22) by means of a hinge connection (28) and to another of the girder members (23) by means of a slide connection (30), wherein another truss member (27) is connected to said another of the girder members (23) by means of another hinge connection (29) and to said one of the girder members (22) by means of another slide connection (31), wherein said truss member and said another truss member cross each other according to a crossing angle (a) associated with the longitudinal direction (Z), and at the location of their crossing point are connected to each other through a scissor hinge connection (34), wherein the slide connections comprise a releasable nominal locking mechanism (32), wherein in the extended state of said at least one mast section the crossing angle of said one truss member and said another truss member is relatively large and said one truss member and said another truss member are locked at a nominal lock position of the corresponding slide connection, and wherein in the retracted state of the mast section the crossing angle of said one truss member and said another truss member is relatively small and said truss member and said another truss member are unlocked with respect to the nominal lock position. cl2. A method for providing an ultra large crane (10) according to any one of clauses cl-clO, comprising:

providing a series of mast sections (20) according to clause cl 1;

transferring the mast sections (20) into a retracted state with reduced width (ΔΧτ); - transporting the mast sections (20) in said retracted state to a predetermined location;

providing a base (16) and guy wire gear (18) at the predetermined location;

after arrival at the predetermined location, transferring the mast sections (20) into a extended state by:

- enlarging a distance between girder members (22, 23) of each mast section

(20) and consequently increasing a crossing angle (a) of the associated truss members (26, 27) thereof; after obtaining the nominal width (ΔΧη) of the mast sections (20), activating nominal locking mechanisms (32) of associated slide connections (30,

31);

forming a mast (12) of the crane (10) by connecting the mast sections (20) in the extended state end to end to each other, and

placing a lower end of the mast (12) on the base (16) and applying the guy wire gear (18) between a top of the mast and the base.

LIST OF REFERENCE SYMBOLS

Similar reference numbers that have been used in the description to indicate similar elements (but having e.g. different indices a, b, i, j etc.) have been omitted from the list below, but should be considered implicitly included.

10 ultra large crane

12 mast

13 first mast end

14 second mast end

16 base

18 guy wire gear

20 mast section

22 first girder member

23 second girder member

24 first girder end

25 second girder end

26 first truss member

27 second truss member

28 first hinge connection

29 second hinge connection

30 first slide connection

31 second slide connection

32 first nominal locking mechanism

33 second nominal locking mechanism

34 scissor hinge connection

36 transport locking mechanism

38 first truss bar (outer bar)

39 second truss bar (inner bar)

40 bracing bar

42 truss member pair

X first transverse direction

Y second transverse direction

z longitudinal direction

Zn nominal lock position Zr reduced lock position

ΔΧη nominal distance

ΔΧΓ reduced distance

ΔΖ longitudinal distance

α crossing angle

αη nominal crossing angle

ar reduced crossing angle

β complementary angle (e.g. β = 180° - a)