EP2868805A1 - Lifting device with form-stable clamping element - Google Patents

Abstract

Device for clamping a device (3) on an elongate body (2) extending in a longitudinal direction (L), which is displaceable back and forth along a longitudinal extent of the elongated body and provided with a self-locking mechanism, which at least one about an associated axis of rotation ( 21) between at least one clamping position and a neutral position pivotable clamping element (20), wherein the at least one clamping element (20) from its axis of rotation (21) extending away arm having at least one arranged on one of the axis of rotation (21) arm end clamping surface ( 22, 23) and the at least one clamping surface (22, 23) in the at least one clamping position and in the neutral position and each position along the pivoting movement has the same relative position to the arm.

Description

The invention relates to a device for clamping a device to a longitudinally extending elongated body which is displaceable along a longitudinal extent of the elongated body and equipped with a self-locking mechanism which at least one about an associated axis of rotation between a clamping position and a neutral position includes pivotable clamping element. The invention also relates to a method of installation and a method for uninstalling an offshore installation.

Devices for moving a device along an elongate body are known in particular in the form of lifting devices and their use for offshore installations. With lifting devices offshore facilities such as platforms, which include at least one support leg, built on the seabed.

The offshore platform will be deployed to the area defined in the sea. There, the legs are carefully lowered by means of a lifting device on the seabed or a pre-installed base frame, and after the legs are firmly established on the seabed or base frame, by means of the same or another lifting device, the floating on the sea water platform is raised in operating height on the wave.

When the platform has reached its operating height by means of the lifting device, it is fixed there.

From the US 2,775,869 is a pneumatic lifting device known. There are two revolving rows of pneumatically operated expandable clamping tubes disclosed per support leg. Stacked clamping tubes are connected to each other by a pneumatically operated air spring. Disadvantageously, the clamping action decreases in case of a defect in the air pressure supply, and the support legs slip through the circumferential expandable clamping tubes.

In the US 2,841,961 is a lifting device with two a support leg rotating rows of grab shoes described. The gripper shoes have pointing to the Stützbeinwandung teeth that press in the tensioned state in the wall material and can damage it disadvantageously. The clamping device of US 2,841,961 has the Disadvantage that the large arranged form-fitting along the circumference of the support leg shoes are difficult to manufacture. In addition, a complicated and energy-consuming mechanism for controlling the clamping mechanism is necessary.

The US 2,822,670 relates to a lifting device with an engagement mechanism. In this case, locking bolts are inserted into recesses in the wall of the support legs and the weight supported on them. Disadvantageously, the support legs must be perforated to accommodate the locking bolt regularly over the entire length provided for the displacement length with holes that weaken their stability, on the other hand, the size of the lifting steps is determined by the distance of the recesses and beyond not adjustable.

In the US 4,002,038 a lifting device is described which comprises ring-segment-shaped clamping elements, the position of which is held by means of pins supporting leaf springs. The clamping elements are arranged semicircular in guides movable. A disadvantage of the mechanism is that the holding of the position by means of a leaf spring is uncertain.

The EP 0030540 relates to a clamping system for clamping a platform to a strip of a support leg. Two pairs of elliptical clamping elements have clamping action in opposite directions. The clamping elements of each pair are interconnected by means of a cylinder and produce by clamping the clamping elements of a pair their clamping action. The system disadvantageously requires a working cylinder for clamping. The system is disadvantageously also not to move a platform along the support leg. The invention is delimited from this document.

In the US 3,396,945 a lifting device for moving a platform along a strip of a support leg is described. The clamping elements have an inclined outer surface which cooperates with an oblique inner surface of a housing to form a clamping effect. Disadvantageously, the slipping of the inclined outer and inner surfaces is associated with a heavy material load.

It is therefore an object of the invention to provide a device of the type mentioned above, which holds a greater reliability and provide a method available that allows easy installation and removal of an offshore facility.

The object is achieved in terms of the device by an aforementioned device with the features of claim 1.

The device for clamping a device mentioned at the outset is preferably a lifting device and the elongate body is a support leg, preferably a cross-sectionally circular support leg, and the device is an offshore device, preferably an offshore platform a support leg or a plurality, preferably 3, 4 or more support legs.

Preferably, the at least one clamping element is structurally particularly favorable. The clamping element has an arm extending away from the axis of rotation and having a preferably flat or curved clamping surface arranged at an arm end facing away from the axis of rotation, the clamping surface having the same relative position to the arm in the clamping position and the neutral position and along the pivoting movement.

The clamping surface provides contact points or areas for contact with the elongated body. The elongate body has an outer surface, which is preferably free of curvature in one of the two surface directions. For example, a cylindrical outer surface of a support leg along a longitudinal direction of the support leg is formed without curvature. A flat clamping surface is also formed without curvature in one of the surface directions, the curvilinear direction of the clamping surface and the curvilinear direction of the outer surface of the elongate body coinciding in the clamping position. As a result, the force exerted on the elongated body in the clamping position is distributed over a larger area and thus spares the elongated body.

In addition, because the clamping elements each have only a single axis of rotation, a simple control of the device is advantageously possible.

In particular, the elongate body-mounted device is suitable without further modification both for lowering the elongated body, preferably the support leg through the offshore platform to the seabed, and for lifting the device, preferably the platform, along the elongated body to operating height.

The term clamping is to be understood here in general. It includes the clamping effect of friction-enhancing documents on the clamping surfaces such as elastomers and friction materials bonded in synthetic resins known from brakes and clutches, but also that Presence of serrations, teeth, rows of teeth on the clamping surfaces, which can penetrate into outer walls of the elongated body.

A clamping position is understood to mean an angular position of the clamping element in which the associated planar clamping surface makes contact with an outer wall of the elongated body and uses the self-locking. A neutral position is understood to mean an angular position of the clamping element in which the clamping element, in particular the at least one clamping surface, has no direct contact with the outer wall of the elongated body. The clamping position can also u depending on the weight of the device. Ä. vary within predetermined angular ranges, and the neutral position may also include an angular range. The clamping element may comprise one, two or a greater number of clamping surfaces, and preferably each clamping surface is associated with a clamping position.

Preferably, the arm of the at least one clamping element is formed dimensionally stable between its axis of rotation and the at least one clamping surface of the clamping element. This is a particularly low-maintenance embodiment of the invention.

Conveniently, the at least one clamping surface traverses with its during the pivoting movement of the neutral position into the clamping position leading portion a pivot line with a smaller radius than a trailing portion of the at least one clamping surface.

Different points and parts of the clamping element describe during the pivoting movement usually different pivot lines. In particular, the points along the clamping surface describe pivoting radii of different diameters. Preferably, the more the range of the clamping surface of the pivoting movement travels after the pivoting radius of the region of the clamping surface increases, when the pivoting movement from the neutral position to a clamping position. By this geometric arrangement of the clamping surfaces relative to the axis of rotation a simple self-locking is achieved by reducing the clamping cross-section.

Preferably, a center of the clamping surface is spaced in the clamping position parallel to the clamping surface by a short lever and perpendicular to the clamping surface about a long lever from the axis of rotation. The ratio of long to short lever corresponds at least to the coefficient of friction between the clamping surface and the outer wall of the elongated body. The weight force acting on the outside of the clamping element, generated via the Leverage of long and short leverage a clamping force acting on the elongated body, the quotient of weight and clamping force corresponds to the quotient of short to long lever. Because the friction corresponds to at least the clamping force multiplied by the coefficient of friction, inhibition occurs at a lever ratio which corresponds to the friction coefficient.

Conveniently, the self-locking mechanism can inhibit both the forward and rearward displacement of the device along the elongated body. The self-locking mechanism is preferably designed twice per clamping element and inhibits depending on the setting at a certain time either the back or the Herverschiebung.

The at least one clamping element preferably has, in addition to the one clamping surface, a further clamping surface. The clamping surface and the further clamping surface are preferably symmetrical to each other. Conveniently, the clamping element in a pivoting plane has a cross-section with along the cross-section at an angle to each other standing clamping surfaces, which are separated by a distance range.

By the formation of two clamping surfaces, it is conveniently possible to produce clamping effects in two directions of movement along the elongate body and thus double-form the self-locking mechanism in a particularly simple manner. In the formation of the device as a lifting and lowering device and in particular in the training as a lifting device both a lowering of the support leg as well as a lifting of the platform can be performed without having to rebuild the device on the support leg or as in Litzenheber- / Senksystem without another independent Senksystem ready. The distance range corresponds to the neutral position. If the distance region is aligned parallel to the longitudinal direction, ie directly opposite the outer wall of the elongate body during operation, the clamping element has no direct contact with the elongate body, and there is no clamping action. Depending on the direction in which the clamping element is pivoted about the axis of rotation, a clamping action between the clamping surface or a further clamping action between the further clamping surface forms in each case with the elongated body, and prevents slippage of the elongated body in the longitudinal direction or against the longitudinal direction the device according to the invention.

The clamping element can be designed differently. The at least one clamping surface may be integrally connected integrally with the respective arms. Preferably, the at least one clamping surface on a guide into which at least one terminal block is inserted. The terminal blocks of a guide form the at least one clamping surface. One, two, three or possibly a higher number of terminal blocks can be inserted in the guide. The guide does not need to be completely filled up. The individual terminal blocks are conveniently fixed separately in the guide. Depending on the number of terminal blocks, the size of the clamping surface changes, and thus the size of the clamping surface and thus the force acting on the outer wall of the elongated body per surface force is adjustable. In particular, individual terminal blocks can be fixed at different positions along the guide. Further outside of the vertical connecting line between the axis of rotation of the clamping element and the outer wall of the elongated body arranged clamping blocks generate a lower clamping force on the outer wall of the elongated body. Thus, the clamping force is adjustable by moving the terminal block in the guide.

The clamping elements are arranged differently around the elongated body in different embodiments of the invention.

Preferably, the clamping elements are arranged in clamping members of a contiguous clamping chain arranged around the elongated body. The clamping members are preferably arranged around the elongated body and adjacent clamping members are preferably hinged together with long connecting straps. The long connection tabs desirably have no contact with the outer wall of the elongated body during operation. The connecting straps are preferably straight. The clamping members themselves may have individual boxes, which in turn are hinged together by short connecting straps. Short and long connecting straps are preferably arranged along the circumference of the elongate body and each formed straight tangentially to the circumference.

Conveniently, the self-locking mechanism comprises clamping members which can be arranged around the elongated body and each having at least one clamping element, wherein the at least one clamping element is pivotable relative to the clamping members about its respective axis of rotation and forms a resizable clamping cross-section around the body. The clamping members may each be formed as one, two, three or a larger number of boxes and a plurality of longitudinally superimposed clamping elements, preferably per box by an actuating rod connected to each other, which allows simultaneous adjustment of the clamping elements of a box.

The control rod makes it possible in particular to adjust the actuatable by them clamping elements for generating an initial inhibition. The self-locking is formed by the later occurring after the initial inhibition, itself by the weight of the device self-reinforcing clamping force.

In a particularly preferred embodiment of the invention, the clamping elements are arranged in at least two clamping member groups, which are movable relative to each other along the elongated body, and each of the clamping member groups forms its own self-locking mechanism.

This embodiment allows in the longitudinal direction and against the longitudinal direction a movement of the two clamping member groups in Nachziehschritt.

In one embodiment of the invention, a clamping member group is provided relatively fixed position to the platform, and the other clamping member group is designed by means of hydraulically operated cylinder relatively movable to the platform. Thereby, the redrawing step between the two clamping member groups is made possible. It is conceivable that the two clamping member groups are directly connected to one another by hydraulically operated cylinders or the hydraulically operated cylinders connect the further clamping member group directly to the platform.

The clamping member groups can be designed differently. Preferably, the clamping members of a group are formed as a clamping chain. There are preferably provided two clamping chains, which are arranged one above the other in the longitudinal direction of the support leg and allow both a lifting of the platform in Nachziehschritt and a lowering of the platform in Nachziehschritt and a lowering and lifting of the support leg. In addition, the device according to the invention as a clamping system is also suitable to keep the platform permanently in the operating position. There are no further and additional fastening means necessary for operation, because the device according to the invention is reliable in the clamping state by self-locking. In addition, a redundancy can be achieved on each support leg due to the double execution of the clamping chains.

In another embodiment of the invention, the clamping member groups are not as clamping chains, an elongated body, preferably the support leg, trained, but the clamping members are U-shaped profile and have on the inside of the U-profile opposite clamping elements between which an am elongated body fixed strip is feasible. The clamping members of a clamping member group may be provided opposite to the support leg on each strip or the support leg circumferentially on a plurality of strips. The clamping members of a clamping member group are not directly connected with each other, but they unfold their clamping action together.
Conveniently, at least one stop for the clamping element is provided, which prevents pivoting of the clamping element in the pivoting direction beyond the clamping position. This is a security feature of the device.

Preferably, teeth are arranged on the clamping surfaces, which engage in the outer surface of the elongate body and increase the clamping effect. It is also conceivable that the clamping surfaces with a friction-enhancing elastomer layer and known from brakes and clutches friction materials bound in synthetic resins are otherwise occupied in order to achieve an increased clamping effect.

The object is achieved in terms of the method by a method for installing an offshore device with a platform and at least one support leg with an aforementioned device having at least two, preferably exactly two clamping member groups. The device is mounted around the at least one support leg, and alternately unfold the clamping surfaces of the clamping elements of the two clamping member groups a clamping action on the support leg. In this way, the support leg is lowered in the Nachziehschritt with the device against the longitudinal direction. According to the invention, the clamping elements of both clamping member groups can be pivoted through their neutral positions, and then alternately unfold the other clamping surfaces of the clamping elements of the two clamping member groups a clamping action on the support leg and so lift the platform in the longitudinal direction to operating height. Advantageously, can be dispensed with a conversion, that is, in particular to open and close again one or both clamping chains.

Preferably, the platform is permanently clamped at operating altitude by means of the device. It can thus on additional fasteners such as bolts o. Ä. be dispensed with for permanent attachment of the platform, because the self-locking device is sufficiently safe to keep the platform permanently in operating altitude.

In another embodiment of the invention, the platform lifting device is used, and the platform, which has been raised to operating height, is permanently attached to the support legs by means of further attachment means.

The object is achieved in terms of the method by a method for uninstalling an offshore device with a platform and at least one support leg with a device above with at least two, preferably exactly two clamping member groups by alternately the other clamping surfaces of the clamping elements of the two clamping member groups a clamping action unfold at least one support leg and so the platform is lowered in Nachziehschritt with the device against the longitudinal direction to the sea surface, the clamping elements are pivoted through their neutral positions and then alternately unfold the clamping surfaces of the clamping elements of the two clamping member groups a clamping action on the support leg and so the at least one support leg is retracted in the longitudinal direction.

Advantageously, can be dispensed with a rebuilding of the device both during installation and during uninstallation, because preferably all clamping elements are swung by changing their relative movement of either support leg or platform to the seabed while maintaining the relative movement direction between the support leg and platform through their respective neutral position.

The invention will be described with reference to several embodiments in nine figures.

Fig. 1

eine perspektivische Ansicht einer erfindungsgemäßen Hubeinrichtung,

Fig. 2

eine Schnittansicht entlang der Linie II/II in Fig. 1,

Fig. 3

eine perspektivische Ansicht eines erfindungsgemäßen Klemmelementes,

Fig. 4

eine zweite Ausführungsform einer erfindungsgemäßen Hubeinrichtung,

Fig. 5

eine perspektivische Ansicht eines Klemmgliedes in Fig. 4,

Fig. 6a

eine Seitenansicht eines ersten Klemmelementes in einer Neutralstellung,

Fig. 6b

eine Seitenansicht des ersten Klemmelementes in Fig. 6a in einer weiteren Klemmstellung

Fig. 7a

eine perspektivische Ansicht eines zweiten Klemmelementes,

Fig. 7b, 7c, 7d

eine perspektivische Ansicht des zweiten Klemmelementes mit jeweils genau einem Klemmbaustein pro Klemmfläche,

Fig. 8

eine seitliche Ansicht eines dritten Klemmelementes in einer Freistellung,

Fig. 9

eine seitliche Ansicht des dritten Klemmelementes in einer Klemmstellung.

Showing:

Fig. 1

a perspective view of a lifting device according to the invention,

Fig. 2

a sectional view taken along the line II / II in Fig. 1 .

Fig. 3

a perspective view of a clamping element according to the invention,

Fig. 4

a second embodiment of a lifting device according to the invention,

Fig. 5

a perspective view of a clamping member in Fig. 4 .

Fig. 6a

a side view of a first clamping element in a neutral position,

Fig. 6b

a side view of the first clamping element in Fig. 6a in another clamping position

Fig. 7a

a perspective view of a second clamping element,

Fig. 7b, 7c, 7d

a perspective view of the second clamping element, each with exactly one terminal block per clamping surface,

Fig. 8

a side view of a third clamping element in an exemption,

Fig. 9

a lateral view of the third clamping element in a clamping position.

Fig. 1 shows the lifting device 1 according to the invention in its basic structure. In Fig. 1 an offshore device is indicated with one of at least three, conveniently four support legs 2 and a platform 3. The platform 3 is not shown in its entire extent, but only the extended to the support leg 2 area. The offshore facility may be buoyant, and it is deployed with the support legs 2 raised to the pre-installation area in the sea. It is also conceivable that she is not buoyant and is placed on a barge overlying.

The lifting device 1 comprises a clamping chain 4 and a further clamping chain 6. The two clamping chains 4, 6 are substantially identical. The support leg 2 is movable relative to the platform 3 in a longitudinal direction L back and forth. It can be lowered or lifted through an opening in the platform 3 with the lifting device 1. The lifting device 1 allows lifting as well as lowering the platform 3 along the founded support leg. 2

To carry out the installation, first the raised support legs 2 with the lifting device 1 are lowered onto the seabed. The seabed can be pre-prepared. The lowered support legs 2 can go directly to the seabed or be placed on a previously installed on the seabed base frame. On the support legs 2, a common bottom body may be attached. Then with the lifting device 1, the platform 3, which floats in the sea, lifted out of the sea and lifted along the support leg 2 up to operating altitude and permanently attached to operating height on the support leg 2.

A movement of the lifting device 1 along the support leg 2 takes place in both directions along the longitudinal direction L in Nachziehschritt the two clamping chains 4, 6. A movement of the lifting device 1 in the direction away from the seabed along the support leg 2 for lifting the platform 3 from the sea is like follows: First, the one clamping chain 4 is clamped on the support leg 2, the further clamping chain 6 is released on the support leg 2, and between the two clamping chains 4, 6 arranged cylinder 7 are retracted, and thus the platform 3 is lifted by the stroke of the cylinder 7 , Then the further clamping chain 6 is clamped on the support leg 2. The one clamping chain 4 is released, and arranged between the two clamping chains 4, 6 cylinders 7 are extended. The one clamping chain 4 is thereby moved along the support leg 2 upwards and in a position above, d. H. further clamped away from the seabed on the support leg 2 again, the further clamping chain 6 is then released, the cylinder 7 are retracted, and thereby the platform 3 is raised again a further distance to the cylinder stroke. Thus, the platform 3 is raised in the Nachziehschritt along the support leg 2 out of the sea to operating altitude. Accordingly, the platform 3 can be lowered, and in a similar manner, the initially raised and not anchored support leg 2 of the offshore installation can be lowered from top to bottom to the seabed through the opening of the platform 3 by means of the lifting device 1.

The two clamping chains 4, 6 of the lifting device 1 are substantially identical. The one clamping chain 4 is here in operation on the support leg 2 from the seabed further away than the further clamping chain 6 is arranged. Each of the two clamping chains 4, 6 has a plurality of clamping members 10, which may also be in the form of a plurality of parallel next to each other, along the circumference of the support leg 2 arranged boxes 11 may be formed.

Immediately adjacent boxes 11 of each clamping member 10 are connected by short straight connecting plates 12 hinged together. Immediately adjacent arranged clamping members 10 are connected by means of circumferentially around the support leg 2 extending straight long connecting plates 13 hinged together. The long connecting straps 13 are longer than the short connecting straps 12. The two clamping chains 4, 6 are movable relative to each other in and against the longitudinal direction L. In the longitudinal direction L exactly opposite clamping members 10 of the two clamping chains 4, 6 are connected in pairs by one of the cylinder 7.

The boxes 11 are identical, a sectional view of one of the boxes 11 is in Fig. 2 to see. In the longitudinal direction L, a plurality of clamping elements 20 are arranged pivotable about each rotation axis 21 along each box 11. The axes of rotation 21 are fixed in position to the box 11 and thus positionally fixed to the associated clamping chain 4, 6 are arranged. The axes of rotation 21 are arranged tangentially to the outer wall of the support leg 2. The clamping elements 20 are on the inside over a radial extent of the box 11 also from in order to form a contact with an outer wall of the support leg 2. On the outside stand from the box 11 eyelets 26 for the short or long connecting plates 12, 13 from. Under 'inside' basically the direction to the support leg 2 is indicative and under 'outside' the direction of the support leg 2 pointing away. In the circumferential direction laterally, the clamping elements 20 of a box 11 are all connected to a not shown, vertically extending control rod, which makes it possible to adjust the clamping elements 20 of a box 11 at the same time and in their entirety rectified. The box 11 has on the inside rollers 25, which ensure a minimum distance of the box 11 to the outer wall of the support leg 2. In particular, the rollers 25 allow the two clamping chains 4, 6 placed around the support leg 2 to be tensioned even in a neutral position of the clamping elements 20 and still allow a displacement in the longitudinal direction L.

Fig. 3 shows one of the identical clamping elements 20 of Fig. 2 in a perspective view. A recess for the implementation of the axis of rotation 21 is in the Fig. 3 but not shown. The clamping element 20 is substantially pie-shaped with a rounded tip through which the (not shown) axis of rotation 21 is guided. The inner circumference of the clamping element 20, which faces the support leg 2 during operation, has three surfaces which are each straight and in each case set at an angle. A clamping surface 22 and a further clamping surface 23 each have horizontal, perpendicular to the longitudinal direction L extending teeth 22a, 23a. Between the two clamping surfaces 22, 23, a flat spacer portion 24 is provided, which has no teeth and is smooth.

With reference to Fig. 2 the operation of the clamping elements 20 will be described. First, the two clamping chains 4, 6 clamped tightly around the support leg 2. In this case, preferably each game from the two clamping chains 4, 6 stretched out to allow the later functionally commencing clamping action of the two clamping chains 4, 6. After the two clamping chains 4, 6 are tensioned, the rollers 25 of each of the boxes 11 are under the action of force on the outer wall of the support leg 2. The but both clamping chains 4, 6 remain movable in the longitudinal direction L back and forth when the clamping elements 20 are in the neutral position.

The flat spacing regions 24 are in the in FIG Fig. 2 illustrated neutral position not in contact with the outer wall of the support leg 2, but a distance from the outer wall of the support leg 2, about 2 mm to 4 mm, spaced. In the neutral position, the distance regions 24 of the outer wall of the support leg 2 are directly opposite. In the neutral position, the associated clamping chain 4, 6 are moved along the support leg 2.

It must, so that the clamping elements 20 perform a rotational movement by train to the box 11 and thereby to be able to build a clamping force F _N , initially an initial clamping of the clamping elements 20 are formed on the outer wall of the support leg 2. For this purpose, the clamping elements 20 are rotated from the neutral position. The initial clamping is made by moving a control rod, not shown, which initially rotates the clamping elements 20 counterclockwise from the neutral position until contact between the further clamping surface 23 and the outer wall of the support leg 2 for each of the clamping elements 20 is made. Due to the initial clamping, a further relative movement of the support leg 2 to the clamping elements 20 leads to a friction-induced further rotational movement of the clamping elements 20 up to the designally provided clamping position, in which the defined clamping force F _N acts on the support leg 2. The defined clamping force F _N is determined by the construction. The initial clamping prevents a subsequent action of a tensile force on the lower cylinder 7 slipping of the two clamping elements 4, 6 on the outer wall of the support leg 2 and triggers the actual self-clamping.

If, after the initial clamping, a tensile force acts in the longitudinal direction L on the cylinder 7, from the in Fig. 2 only a small part is shown, for example, by the fact that the weight of hanging on the cylinder 7 platform 3 pulls over the cylinder 7 on the box 11, the box 11 is pulled down to the seabed, and the clamping elements 20 are a small angle on is rotated counterclockwise, and the clamping force F _N on the support leg 2 is increased until the defined clamping force F _N acts on the support leg 2. The teeth 23a of the clamping surface 23 engage in the outer wall of the support leg 2, and the eight clamping elements 20 rotate counterclockwise through the force of the further downward pull on the box 11. Due to the geometry of the clamping element 20 is formed by the rotational movement of an increasing clamping action and the increasing clamping force F _{N of} the clamping element 20 on the outer wall of the Support leg 2 off. The geometric design of the in the Fig. 2 shown clamping element 20 is in the Fig. 6 shown. A second embodiment of the clamping element 20 shows the Fig. 7 ,

FIGS. 4 and 5 show a lifting device 1, which also the clamping elements 20 of the Fig. 3 includes, but no contiguous circumferential clamping chains 4, 6 according to Fig. 1 , Fig. 4 shows the clamping members 10 which are arranged in a support member 2 rotating around the clamping member group, the clamping member group corresponds in function to that of a clamping chain 4 in Fig. 1 ,

One of the clamping members 10 is in Fig. 5 shown in more detail. The clamping member 10 has a U-profile 50, on whose opposite legs on the inside in each case a row of three clamping elements 20 is arranged. The clamping elements 20 of the two rows are on a flat strip 51 in pairs exactly opposite. The clamping elements 20 are pivotable about the mutually parallel axes of rotation 21. The axes of rotation 21 are aligned in the radial direction of the support leg 2. The two rows of clamping elements 20 are spaced so far apart that they exert a clamping action on the flat strip 51 guided between them. The flat strip 51 is fixed with one of its narrow longitudinal edges on the outer wall of the support leg 2, for example, welded. The clamping members 10 thus do not form according to Fig. 1 one of the two support legs 2 circumferential clamping chains 4, 6, the clamping members 10 are connected by circumferential long connecting plates 13 with each other, but the clamping members 10 of the clamping member group are not directly connected to each other; they only work together by simultaneously developing or releasing a clamping action. The clamping members 10 are according to Fig. 4 with two cylinders 7 firmly connected. The cylinders 7 are on the side facing away from the clamping member 10, for example, directly connected to the platform 3 or with another of the clamping members 10 which engages in the same flat strip 51.

Fig. 6a and Fig. 6b show side views of a clamping element 20 according to Fig. 4 or Fig. 2 , The Fig. 6a shows the clamping member 20 in a neutral position in which the clamping member 20 has no direct contact with the outer wall of the support leg 2. The Fig. 6b shows the clamping element 20 in the further clamping position. In the further clamping position, the further clamping surface 23 makes contact with the outer wall of the support leg 2. The clamping element 20 has a symmetry surface 60, on which the clamping element 20 is mirror-symmetrical. A surface normal of the symmetry surface 60 is tangential to the pivot direction R of the clamping element 20 arranged. The clamping element 20 has the clamping surface 22 opposite the symmetry surface 60 of the further clamping surface 23. Fig. 6a shows that the clamping member 20 between a clamping position in which the clamping surface 22 has direct contact with the outer wall of the support leg 2, and the other clamping position in which the further clamping surface 23 makes contact with the outer wall of the support leg 2, by the neutral position according to Fig. 6a is pivotable back and forth

A vertical connecting line 61, which intersects a center of the rotation axis 21 and is perpendicular to the outer wall of the support leg 2, passes through the further clamping surface 23 in the further clamping position Fig. 6b through, and she does not limit it exactly. The further clamping surface 23 is perpendicular to the axis of rotation 21 in a long lever arm LH. The center of the further clamping surface 23 is arranged in a short lever arm KH offset from the axis of rotation 21.

With a material combination of further clamping surfaces 23 and the outer wall of the support leg 2 with a coefficient of friction p of, for example, p <0.2, the geometry is designed so that the clamping force F _{N is} five times greater than the axial force F and thus a sufficiently inhibiting frictional force F. _R generates.

Fig. 7a shows a perspective view of a second embodiment of the clamping element 20 according to the invention. The clamping element 20 is in turn formed on the symmetry surface 60 mirror-symmetrical. The clamping element 20 has a circular opening for the axis of rotation 21. Again, the clamping surface 22 and the further clamping surface 23 are formed mirror-symmetrically along the symmetry surface 60. The clamping surface 22 has three clamping elements 70 each having a circular contact surface. The three annular surfaces 71 together form the further clamping surface 23 of the clamping element 20. The clamping element 20 has two lateral cheeks 72, which are spaced apart from each other and have two outer guides 74. The clamping blocks 70 are flared on their sides facing the cheeks 72 and inserted into the corresponding guide 74, which is formed between the two cheeks 72, directly touching. Each of the two guides 74 is limited at its the symmetry surface 60 facing the end with a T-shaped stop member 76. The T-shaped stop member 76 has a the support leg 2 facing flat surface which projects slightly beyond a plane of the conical guide piece of the clamping block 70 out, but remains behind the clamping surface 22, 23. As a result, even with relative movements of the support leg 2 in the horizontal direction relative to the platform 3 and the clamping device, a stable clamping state guaranteed. A T-leg of the T-shaped stopper 76 is inserted between the two cheeks 72 in the clamping member 20.

The FIGS. 7b . 7c and 7d show the embodiment of the clamping element 20 of Fig. 7a each in a slightly modified version. The clamping element 20 in Fig. 7b has in each clamping surface 22, 23 each exactly one clamping block 70 which is directly adjacent to the T-shaped stop member 76 and in contact with the T-shaped stop member 76 in the respective guide 74 of the clamping surface 22, 23 is provided. The two terminal blocks 70 of the embodiment according to Fig. 4b are inserted at the mutually facing ends of the two guides 74 in the guides 74. Fig. 7c shows an embodiment of the clamping element 20, each with one of the clamping blocks 70 in each of the two guides 74, wherein the clamping block 70 is provided respectively at the outer end of the guides 74, so that the two clamping blocks 70 have a maximum distance from each other. Fig. 7d shows an embodiment in which the two clamping blocks 70 are provided centrally in the respective guide 74. Embodiments with mixed positions of the clamping blocks 70 in the respective guide 74 are also conceivable.

The different arrangement and number of clamping blocks 70 allows a different distribution of the clamping force F _N. The clamping blocks 70 are displaceable along the guides 74 and fixed in any position along the guides 74. Due to the different arrangement of the clamping blocks 70 along the guides 74, the ratio of the clamping force F _N to the frictional force F _{R can be} adjusted.

In the FIGS. 8th and 9 a further embodiment of a clamping element 20 according to the invention is disclosed, for example, in one of the two clamping chains 4, 6 of the Fig. 1 , but also in the clamping member 10 according to the FIGS. 4 and 5 can be installed. The principle of clamping corresponds to that by the clamping elements 20 according to Fig. 6 or Fig. 7 , However, the clamping element 20 of the FIGS. 8th and 9 only in each case exactly one clamping surface 22.

LIST OF REFERENCE NUMBERS

1

lifting device

2

outrigger

3

platform

4

clamping chain

6

another clamping chain

7

cylinder

10

clamping members

11

boxing

12

short connecting straps

13

long connecting straps

20

clamping elements

21

axis of rotation

22

clamping surface

22a

teeth

23

additional clamping surface

23a

teeth

24

flat distance ranges

25

roll

26

eyelets

50

U-profile

51

flat strips

60

plane of symmetry

61

vertical connecting line

62

diagonal

70

terminal blocks

71

annular surfaces

72

lateral cheeks

74

guides

76

T-shaped stop piece

KH

short lever arm

LH

long lever arm

L

longitudinal direction

F

axial force

F _N

clamping force

F _R

frictional force

R

pan direction

μ

friction

Claims (15)

Device for clamping a device (3) on an elongate body (2) extending in a longitudinal direction (L), which is displaceable back and forth along a longitudinal extent of the elongated body (2) and provided with a self-locking mechanism, which at least one around associated rotational axis (21) between at least one clamping position and a neutral position pivotable clamping element (20),
characterized in that the at least one clamping element (20) has an arm extending away from its axis of rotation (21) with at least one clamping surface (22, 23) remote from an arm axis (21) and in that the at least one clamping surface ( 22, 23) in the at least one clamping position and in the neutral position and each position along the pivoting movement has the same relative position to the arm. Device according to claim 1,
characterized in that the arm is dimensionally stable between the axis of rotation (21) and the at least one clamping surface (22, 23) is formed. Device according to one of claims 1 or 2,
characterized in that the self-locking mechanism inhibits both the forward and rearward displacement of the device along the elongated body. Device according to one of claims 1, 2 or 3,
characterized in that the at least one clamping surface (22, 23) is flat. Device according to one of claims 1 to 4,
characterized in that the at least one clamping element (20) between the clamping position, in which the movement along the longitudinal extent of the elongated body (2) is self-inhibited, and a further clamping position, in which the forward movement along the longitudinal extent of the elongated body (2) self-inhibited is, about the neutral position is pivotable. Device according to one of the preceding claims,
characterized in that the at least one clamping surface (22, 23) with its During the pivoting movement of the neutral position in the clamping position leading portion a pivot line with a smaller radius than a trailing portion of the at least one clamping surface (22, 23). Device according to one of the preceding claims,
characterized in that the at least one clamping element (20) has at least one guide (74) for clamping blocks (70) and the clamping blocks (70) in the guide (74) are fixable at different positions and thus a clamping force (F _N ) is adjustable , Device according to one of the preceding claims,
characterized in that the self-locking mechanism comprises clamping members (10) arrangeable along a circumference about the elongate body (2), and each clamping member (10) comprises at least one of the clamping members (20) pivotable about its axis of rotation (21) Device according to one of the preceding claims,
characterized in that adjacent clamping members (10) are connected to one another with long connecting straps (13) and the clamping members (10) and the long connecting straps (13) form a clamping chain (4, 6) arranged around the elongate body (2). Device according to one of the preceding claims,
characterized in that the clamping members (10) have a U-profile (50) and inside the U-legs, the opposing clamping elements (20), between which a strip (51) can be guided. Device according to one of the preceding claims,
characterized in that the clamping elements (20) are arranged in at least two clamping member groups, which are movable in the longitudinal direction (L) relative to each other, and each of the clamping member groups forms its own self-locking mechanism. Device according to one of the preceding claims,
characterized in that the clamping elements (20) of a clamping member group together at least one variable in size clamping cross-section form. Device according to claim 12,
characterized in that a clamping member group via hydraulically operated cylinder (7) relative to the device (3) on the device (3) can be fastened and a further clamping member group relatively fixed position to the device (3) on the device (3) can be fastened. Method for installing an offshore installation with a platform (3) and at least one support leg (2) with a device (1) according to one of claims 1 to 13, by
the device (1) is mounted around the at least one support leg (2),
alternately unfold the clamping surfaces (22) of the clamping elements (20) of the two clamping member groups (4, 6) a clamping action on at least one support leg (2) and so the at least one support leg (2) in Nachziehschritt with the device (1) against the longitudinal direction ( L) is lowered to the seabed,
the clamping elements (20) are pivoted through their neutral positions and then alternately unfold the further clamping surfaces (23) of the clamping elements (20) of the two clamping member groups (4, 6) a clamping action on at least one support leg (2) and so the platform (3) in Lengthwise (L) is raised to operating height. A method for uninstalling an offshore device comprising a platform (3) and at least one support leg (2) with a device (1) according to one of claims 1 to 13, by alternating the further clamping surfaces (23) of the clamping elements (20) of the two clamping member groups (4, 6) unfold a clamping action on at least one support leg (2) and so the platform (3) in the Nachziehschritt with the device (1) against the longitudinal direction (L) is lowered to the sea surface, the clamping elements (20) pivoted through their neutral positions and then alternately unfold the clamping surfaces (22) of the clamping elements (20) of the two clamping member groups (4, 6) a clamping action on the support leg (2) and so the at least one support leg (2) retracted in the longitudinal direction (L)

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