EP1953111A2

EP1953111A2 - Hoisting clamp and hoisting mechanism provided therewith

Info

Publication number: EP1953111A2
Application number: EP08150581A
Authority: EP
Inventors: Martinus Marinus Maria Van Berlo; Apollos Adriaan Van Oord
Original assignee: Mammoet Van Oord Holding BV
Current assignee: Van Oord Dredging and Marine Contractores BV
Priority date: 2007-01-24
Filing date: 2008-01-24
Publication date: 2008-08-06
Anticipated expiration: 2028-01-24
Also published as: EP1953111A3; EP1953111B1; NL1033275C2

Abstract

A hoisting clamp comprising a first and a second contact part, mutually connected by a connecting bracket, the first contact part having a first contact surface and the second contact part having a second contact surface, which contact surfaces face each other and have a mutual distance, while a locking bracket is provided, displaceable relative to at least the first and second contact surface, while on the locking bracket a hoisting element and a clamping part are provided, at a distance from each other, the clamping part being operatively movable against an object inserted between the first and second contact surface by exertion of a tensile force on the hoisting element.

Description

The invention relates to a hoisting clamp. The invention relates in particular to a hoisting clamp for use for bringing objects, in particular sections such as tubular sections or box sections, into a vertical position.
Hoisting clamps for gripping objects to be displaced are known from practice. Thus, for instance, hydraulically or pneumatically energized grippers are used for engaging products at a longitudinal edge thereof, so that the products can be brought into and held in a desired position. Also known are hoisting clamps which, for instance, are screwed or clamped to a product, for instance using screw means. The object of the invention is to provide a hoisting clamp which is simple and reliable in use.
In a first aspect, a hoisting clamp according to the invention is characterized by a first and a second contact part, mutually connected by a connecting bracket, the first contact part having a first contact surface and the second contact part having a second contact surface, which contact surfaces face each other and have a mutual distance, while a locking bracket is provided, displaceable relative to at least the first and second contact surface, while on the locking bracket a hoisting element and a clamping part are provided, at a distance from each other, the clamping part being operatively movable against an object inserted between the first and second contact surface by exertion of a tensile force on the hoisting element.
Such a hoisting clamp can be simply slipped over the edge of a product, whereupon by initiating a hoisting movement the edge of the product is clamped tight. The locking bracket, through displacement relative to the contact surfaces, then provides for the desired clamping, which can be simply removed again, for instance by removing hoisting tension.
In a second aspect, a hoisting clamp according to the invention is characterized in that in the hoisting clamp between the contact surfaces and the connecting bracket a receiving space is formed in which an edge of a product to be hoisted can be received, such that the edge can be clamped tight by the locking bracket. The longitudinal edge can then preferably rest on the connecting bracket when the product is being brought into a vertical position. As a result, a particularly advantageous force transmission is obtained.
In a third aspect, the invention is characterized in that the first and/or the second contact surface is made of bent design, such that the first contact surface can be applied along an outer side and the second contact surface along an inner side of a tubular section with a bent outer wall, while the radii of the first and second contact surface preferably correspond to the radii, or the outer and inner surface, respectively, of the tubular section, adjacent the longitudinal edge where the clamping bracket is applied during use.
In a comparable manner, a first and second contact surface can be used that are adapted to a section to be lifted that has a different cross section.
In a fourth aspect, a hoisting clamp according to the invention is characterized in that the locking bracket is provided with a hoisting means to which for instance a hoisting cable or hoisting chain can be attached and by way of which the hoisting clamp can be lifted, such that when an object is arranged between the contact surfaces and the connecting bracket, the clamping part of the locking bracket is clamped against the object when a hoisting force is applied to the hoisting means mentioned.
The invention furthermore relates to a method for hoisting objects, in particular into a vertical position. In such a method, preferably a hoisting clamp according to the invention is used.
In clarification of the invention, embodiments of a hoisting clamp, hoisting mechanism and method according to the invention will be further elucidated with reference to the drawing. In the drawing:

Figs. 1A-F show in a series of steps how a tubular section is taken up from a horizontal position and moved to a vertical position;
Figs. 2, 2A show in side elevation a hoisting clamp according to the invention in open condition;
Fig. 3 shows a hoisting clamp according to Fig. 2 in closed condition;
Fig. 4 shows a hoisting clamp according to Figs. 2 and 3 in front view; and
Figs. 5A-E show a hoisting clamp according to any one of Figs. 2-4 in a series of positions during the performance of a hoisting movement according to Fig. 1.

In this description, the same or corresponding parts have the same or corresponding reference numerals. In this description, 'vertical' is at least understood to mean a line approximately parallel to the direction of the action of the earth's gravity field, unless expressly stated otherwise. The terms left, right, top, bottom, front and back are used in this description as designations relative to the plane of the paper in the respective drawing, unless stated otherwise. 'Approximately' should at least be understood to mean a deviation of plus or minus 10% from a given value, unless expressly stated otherwise.
In this description, as an object to be hoisted, a tubular element will be described, such as a pipe of a cylindrical cross section, also referred to as tubular section. However, the invention is expressly not limited thereto. Thus, a hoisting clamp according to the invention can be used for hoisting up open or closed sections, rectangular or polygonal, regularly or irregularly shaped tubular sections, I-, H-, T-sections, sheet sections, and the like.
Fig. 1A schematically shows in side elevation a tubular section 1 having for instance a cylindrical cross section, disposed on a vessel 2. The tubular section 1 has a longitudinal direction L and, approximately at right angles thereto, a diameter D. In the longitudinal direction, the tubular section 1 has for instance a length between one meter and a few tens of meters. The diameter D is for instance between one decimeter and a few tens of decimeters or more, for instance a few meters. The tubular section 1 has a first end 3 and an opposite second end 4 and may be open at both ends 3, 4. The ends 3, 4 are preferably both formed by a longitudinal edge having a wall thickness d. The tubular section is for instance manufactured from bent and/or drawn plate material such as steel.
Near the first end 3, a hoisting cable 5 has been attached, for instance welded on, fastened to a hoisting eye, a spreader, a hydraulic or pneumatic clamp or the like, such that the entire weight of the tubular section 1 can be borne by the hoisting cable 5. At the second end 4, a hoisting clamp 6 has been attached, to which a second hoisting cable 7 is secured, as will be described in more detail hereinafter. A hoisting clamp 6 is further shown and elucidated with reference to Figs. 2-5.
The length of the second hoisting cable 7 can preferably be adjusted, independently of the length of the first hoisting cable 5, for instance using winches, hoist drums or like hoisting means known per se. In this way, the longitudinal direction L of the tubular section 1 can for instance be brought from a substantially horizontal position as shown in Fig. 1A to a substantially vertical position as shown in Figs. 1 E and F, conventionally also known as "tailing". To allow the tubular section to perform this movement, the hoisting cables 5 and 7 are attached when the section 1 is for instance laid horizontally on supports 8 on a deck 9 of a ship 2 or, for instance, on supports on a vehicle or the ground. From this position, the tubular section 1 is then lifted, with its longitudinal direction L approximately horizontal, until a desired distance to the supports 8 has been obtained, as shown in Fig. 1B. Thereupon, the first hoisting cable 5 is taken in further than the second hoisting cable 7, so that the longitudinal direction is adjusted via the positions as shown in Figs. 1C and 1D to a substantially vertical position, as shown in Fig. IE. Thereupon, the second hoisting cable 7 can be detached by paying it out to some extent or by taking the first hoisting cable in further while keeping the second hoisting cable 7 at the same length or taking it in less, so that the hoisting clamp 6 comes down under the second, then lowermost, end 4 of the tubular section and can be removed. The tubular section such as a pipe can then be moved to a desired position and be secured, for instance on a foundation. The tubular section can for instance form a column of a building, a mast, a construction part of a platform, a mast of a windmill or other construction part known per se.
Naturally, different orders of pickup can be used. For instance, the section may be tilted right away, or it may be moved from a vertical or inclined position to a differently inclined or lying, horizontal position, or the like.
In Figs. 2-5, a hoisting clamp 6 according to the invention is shown, in more detail. This hoisting clamp comprises a first contact part 11 and a second contact part 12, mutually connected by a connecting bracket 30. The first contact part 11 has a first contact surface 13, the second contact part 12 a second contact surface 14. The contact surfaces 13, 14 face each other and have a mutual distance Z, viewed in a direction perpendicular to the two contact surfaces 13, 14. A locking bracket 15 is provided, which is displaceable relative to at least the first 13 and second contact surface 14. A hoisting element 16, such as for instance a hoisting eye, hook, clip or like means for attachment of the second hoisting cable 7, and a clamping part 17 are provided on the locking bracket 15, at a mutual distance X, while the clamping part 17 is operatively movable against an object 1 inserted between the first 13 and second contact surface 14 by exertion of a tensile force F on the hoisting element 16. The tensile force F is preferably exerted by the second hoisting cable 7.
Preferably, by the two contact surfaces 13, 14 and the connecting bracket 30 an insertion space 18 is defined, or at least partly surrounded, such that an end 4 of a tubular section 1 can be inserted therein, approximately parallel to the longitudinal direction L. The distance Z between the two contact surfaces 13, 14 is then preferably approximately equal to the wall thickness d of the tubular section adjacent the second end 4, so that the second end 4 can be inserted, with little clearance, until the second end 4 butts against the connecting bracket 30. The connecting bracket 30 is slightly U-shaped, with a first leg and a second leg, the first contact surface being attached to the first leg and the second contact surface being attached to the second leg.
The locking bracket 15 can preferably be moved by way of the clamping part 17 at least partly into the insertion space 18, against the second end 4 of the tubular section, such that it is clamped. To that end, the locking bracket can be connected with the connecting bracket 30 via a rotation axis 19, the rotation axis 19 being positioned between the clamping part 17 and the hoisting element 16. The tensile force F can then effect a rotation of the locking bracket 15, so that the clamping part 17 is clamped against the tubular section 1 and the tubular section 1 is retained.
As appears from Figs. 2-5, the clamping part 17 is substantially or wholly clear of the tubular section when the hoisting clamp 6 is slipped onto the tubular section 1, by pressing the locking bracket 15 substantially against the connecting bracket 30. Next, the second hoisting cable 7 is pulled tight, whereby the locking bracket 15 rotates to an approximately vertical position, approximately at right angles to the longitudinal direction L, with the tensile force F approximately extending along the line connecting the hoisting element 16 and the rotation axis 19. The clamping part 17 is thereby pressed against the tubular section.
After the second hoisting cable 7 has been pulled tight, the tubular section is lifted and thereupon the longitudinal axis thereof is brought in a substantially vertical orientation. As the tensile force F continues to work in approximately the same direction, the direction of the tensile force F is more and more parallel to the longitudinal direction L of the tubular section, so that the locking bracket 15 is moved closer to the connecting bracket 30. The clamping part 17 is thereby moved towards the tubular section 1, so that the clamping force thereby exerted becomes increasingly greater according as the longitudinal direction L of the tubular section is oriented more vertically.
When the tubular section has its longitudinal direction L oriented substantially vertically, the clamping part 17 can be moved clear of the tubular section 1, and the hoisting clamp 6 can simply come off the tubular section by the influence of gravity. This is because when the second hoisting cable 7 is lengthened relative to the first hoisting cable 5, the clamping part 17 will move away and the hoisting clamp 6 can slide down along the tubular section and eventually come off it because there is no clamping action anymore. In this way, detaching the hoisting clamp requires no human intervention or at least less than in the case of the known hoisting clamps.
Preferably, a hoisting clamp 6 is provided with a stop 20, against which the locking bracket 15 can abut when it is in the loose position. This prevents the locking bracket from rotating too far. The stop is preferably so positioned that the insertion space 18, with the bracket 30 in free position, is oriented approximately horizontally. However, a different angle may be set. The rotation axis 19 is preferably outside the insertion space 18, at a distance from the contact surfaces 13, 14. In this way, it cannot hinder insertion of the tubular section. The connecting bracket 30 is preferably slightly U-shaped, that is, provided with two legs 21 extending in a same direction, approximately next to each other, from a crosspiece 22 (Fig. 2A). The contact surfaces 13, 14 are arranged adjacent the free ends 23, 24 of a first and a second one of the two legs 21, respectively. The first leg 21A can then have a length, measured from the crosspiece, that is greater than the length of the second leg 21B. As a result, the two contact surfaces 13, 14 are spaced apart a distance Y, seen in side view, so that placement of the hoisting clamp 6 is further simplified. During placement and removal, the hoisting clamp can be tilted to some extent, thus allowing simpler access to the insertion space.
The contact surfaces 13, 14 preferably have a slightly angled or bent shape, as shown in Figs. 2 and 2A. The shape is preferably adapted to the outer side 23 and the inner side 24 of the tubular section, respectively, so that a contact surface is obtained that is greater than when using contact surfaces having a shape not adapted to the tubular sections. The contact surfaces may be detachably connected with the connecting bracket and/or the legs thereof, such that they can for instance be adjusted or be replaced with contact surfaces having a different configuration, for instance for adaptation to a different tubular section 1. As a result, the hoisting clamp 6 is rendered more universally applicable. Naturally, each contact surface 13, 14 may also be built up from a series of contact surfaces which are arranged next to each other on a bracket or directly on the connecting bracket. Optionally, the or each contact surface may be provided with a covering, for instance of an elastomer or other relatively soft material, such as a plastic material, so that damage to the tubular section can be further prevented and moreover some friction can be obtained, or a magnetic material.
In a hoisting clamp according to the invention, the center of gravity is preferably located near, in particular in, the rotation axis 19. As a result, the clamp in free position remains in any desired position, so that despite a high weight it can yet be simply turned manually. In a simple manner, this prevents overturning of the hoisting clamp upon detachment from the object to be lifted. The ballast arm 20 with weights is preferably detachable, so that when using a different hoisting clamp, at any rate different contact surfaces, the center of gravity can be placed near the axis 19 again.
A hoisting clamp according to the invention can be used with any type of hoisting mechanism, for instance a crane or hoist, a crab or the like, and may optionally be combined with for instance a spreader. Moreover, the first and second hoisting cable 5, 7 may be provided on different hoisting mechanisms. By way of illustration, in a hoisting clamp according to the invention, each contact surface, in bent design, can for instance have a radius of a few centimeters to a few meters.
The invention is not limited in any way to the embodiments represented in the drawing and description. Many variations thereon are possible within the framework of the invention outlined by the claims. For instance, the hoisting cables 5, 7 may be designed differently, for instance as chains, ropes or the like. The two hoisting cables may be suspended from an adjustable suspension point, for instance a winch with which the length of one of the hoisting cables can be set with respect to the other. The first hoisting cable can be connected to the tubular section at a different position, preferably on a side of a centre of gravity thereof remote from the second end, such that the tubular section, when suspended alone from the first hoisting cable, tilts with its longitudinal direction into a desired position, in particular an approximately vertical position. The components of a hoisting clamp according to the invention can be manufactured, for instance, from metal or other material, and may be shaped differently. For instance, the contact surfaces may be shaped differently, for instance depending on the profile of the tubular section to be lifted. Instead of one connecting bracket, two may be arranged next to each other, with the locking bracket between them, or vice versa. These and many other variations are understood to fall within the framework of the invention outlined by the claims.

Claims

A hoisting clamp, comprising a first and a second contact part, mutually connected by a connecting bracket, the first contact part having a first contact surface and the second contact part having a second contact surface, which contact surfaces face each other and have a mutual distance, while a locking bracket is provided, displaceable relative to at least the first and second contact surface, while on the locking bracket a hoisting element and a clamping part are provided, at a distance from each other, the clamping part being operatively movable against an object inserted between the first and second contact surface by exertion of a tensile force on the hoisting element.
A hoisting clamp according to claim 1, wherein by the first and second contact surface and the connecting bracket an insertion space is defined, while the clamping part is movable into said insertion space.
A hoisting clamp according to any one of the preceding claims, wherein the locking bracket is rotatable about a rotation axis, while the clamping part and the hoisting element are situated on opposite sides of the rotation axis.
A hoisting clamp according to any one of the preceding claims, wherein a stop is provided for limiting the freedom of movement of the locking bracket relative to the connecting bracket and/or the contact surfaces.
A hoisting clamp according to any one of the preceding claims, wherein the locking bracket is connected with the connecting bracket at a distance from the contact surfaces, preferably outside an insertion space defined by the contact surfaces and the connecting bracket.
A hoisting clamp according to any one of the preceding claims, wherein the connecting bracket is slightly U-shaped, having a first and a second leg, the first contact surface being attached to the first leg and the second contact surface being attached to the second leg.
A hoisting clamp according to claim 6, wherein the legs each have a longitudinal direction, which longitudinal directions are parallel, and the first leg is longer than the second leg, measured in the respective longitudinal direction, while the first and second contact surface are arranged adjacent a free end of the first and second leg, respectively.
A hoisting clamp according to claim 6 or 7, wherein the first and second leg are mutually connected by a crosspiece, while the locking bracket is linked with, and in particular attached to, the crosspiece.
A hoisting clamp according to any one of the preceding claims, wherein the first and/or second contact surface is/are bent or angled, such that they define parallel profiles in at least one direction.
A hoisting clamp according to any one of the preceding claims, wherein the first and/or second contact surface is/are detachably connected with the connecting bracket.
A hoisting mechanism provided with a hoisting clamp according to any one of the preceding claims, wherein there are further provided at least a first hoisting cable or hoisting chain by which the hoisting clamp is suspended and a second hoisting cable or hoisting chain provided with fastening means for coupling to an object to be hoisted.
A hoisting mechanism according to claim 11, wherein the length of the second hoisting cable or hoisting chain is adjustable independently of that of the first hoisting cable or hoisting chain.