IL43765A - Gantry cranes - Google Patents

Description

Gantry Cranes D" n nya-m 'may This invention relates to gantry cranes useful .in the erection of structures which comprise several bridge-like sub-structures arranged side by side in spaced relationship. Such a structure may be required, for example, for covering a railway goods yard. In such a case the bridge-like sub-structures span the full width of the goods yard without intermediate supports and are disposed side by side along the length of the goods yard at a spacing appropriate for carrying load-. supporting flooring or the like between them. Buildings or the like may be erected on the structure to afford an, additional use for the goods yard site. Another example of such a structure is a bridge over a river or motorway.

. The erection of the bridge-like sub-structures requires the emplacement of massive structural elements such as blocks or beams of pre-stressed concrete. This can be accomplished by means of a giant gantry crane which spans the structure, the supporting columns being . disposed beyond the ends of the bridge-like sub-structures and these columns being themselves movable on rails or prepared tracks so that the whole crane can be moved forwards as the bridge-like sub-structures are progressively completed to a condition in which they are · self-supporting and laterally stable.

According to the present invention a movable gantry crane useful in the erection of such a structure comprises a girder long enough to span the structure, supported by movable supporting columns, at least two . sets of hangers which suspend a platform from the girder in a position to lie "beneath a bridge-like sub-structuii^H* to be erected with the aid of the crane, at least one set being disposed to occupy a position in front of the said sub-structure and at least one other set being disposed to occupy a position to the rear of the said sub-structure, a lifting device movable along the girder between sets of hangers disposed to occupy positions respectively in front of and to the rear of the said sub-structure, and the hangers of -the said other set or sets being removable or displaceable to permit the crane including the platform to be moved forwards when this sub-structure has been made self-supporting and laterally stable.

The provision of the platform beneath the sub-structure which is being erected with the aid of the crane enables the erection work to be carried on without risk of articles or material employed in the erection falling to the ground if accidentally dropped. Thus the movement of persons or vehicles at ground level can continue safely and without interruption throughout the construction of the whole structure, which may extend over a long period of time. Also, the platform enables the construction work to be carried on without the erection of temporary scaffolding from ground level. However, the presence of platform-supporting hangers behind the sub-structure being erected would prevent the crane from being moved forward, unless these hangers are removable or displaceable. By making these hangers capable of being removed or displaced, the crane can be moved forward together with the platform when a sub-structure has reached a self' supporting and laterally stable condition, so that the erection of the next sub-structure can be commenced.

The hangers positioned in front of the sub-structure being erected need not be removable or displaceable because these hangers do not interfere with the forward movement of the crane. Of course, temporary supports for the rear portion of the platform must be provided when the removable or displaceable hangers are removed or displaced. These temporary supports could be a further set of removable or displaceable hangers disposed further to the rear and which would remain in position until the crane had been moved forward and the removed or displaced set had been repositioned in front of the newly erected sub-structure. This further set would then be removed or displaced to permit further forward movement of the crane.

There may be another lifting device movable along the girder to the rear of the set or sets of removable or displaceable hangers* Preferably the platform is long enough to encompass three sub-strctures. In this case the crane may have a forward working bay served by the first-mentioned lifting device for the erection of the foremost sub-structure and a rear working bay served by the said other lifting device for operations between the two previously erected sub-structures. Thus, while the forward sub-structure is being erected in the forward bay, further work may be carried out between the next two previously erected sub-structures in the rear bay.

The sequence of erection may be as follows: ^J-' 1. The crane is moved forwards to a new position. 2. Construction units for the new sub-structure are brought to the site and hoisted into position, aligned and then jointed, in the forward bay of the crane. In the rear bay, floor and wall units are erected between and upon the two previously erected sub-structures, and temporary stabilising beams connecting these two sub-structures are removed. 3. Stressing cables are threaded and joints cured in the sub-structure in the forward bay, and after curing the cables are stressed. The construction work may continue in the rear bay. 4. Temporary beams are erected between the newly erected sub-structure in the forward bay and the adjacent previously completed sub-structure in the rear bay, to stabilise the new sub-structure laterally. The construction work in the rear bay is completed. 5. The crane is moved forwards to the next position.

The said previously erected sub-structure, being in a. self-supporting and laterally stable condition, can * serve as a temporary support for the platform. For example, the platform may be suspended from this substructure on roller supports, to enable the platform to move forward freely relative to these supports. The platform extends still further to the rear, at least as far as the next previously erected sub-structure, from which it can be supported in a like manner. This enables the construction of the permanent load-supporting flooring between the two completed sub-structures to be carried on safely and easily. ' One or both, ends of the girder of the gantry may project beyond the respective supporting column or columns so that the movable lifting device or devices supported by the girder can pick up loads from a position beyond the column or columns and carry these loads along the girder to the point of use.

The invention may be performed in various ways and a specific embodiment will now be described by way of example with reference to the accompanying somewhat diagrammatic drawings, in which:- Figure 1 is an overhead perspective view of a structure for the erection of which a gantry crane embodying the invention is used; Figure 2 is a perspective view of a gantry crane embodying the invention being used in the erection of parts of the structure shown in Figure 1; Figure 3 is a front elevation of the crane and parts of the structure being erected; Figure 4 is a side elevation of the crane and part of the structure, looking from the left in Figure 3; and Figure.5 is a side elevation of portions of the crane and of the structure, partly in section.

Referring to Figure 1, there is shown a structure 10 which comprises several broad span bridge-like substructures 11a - Ilk arranged side by side in spaced relationship. The structure 10 covers an area 12, such as a railway goods yard or a multi-lane highway.

Extending between the sub-structures 11a - Ilk is load-supporting flooring 13, and on this there are buildings 14. The whole structure 10 is erected in a manner . w described below which enables the area 12 to remain i use throughout the whole period of construction, without risk of articles or materials employed in the construction falling to the ground if accidentally dropped, and without obstruction by the erection of temporary scaffolding from ground level.

For the erection of the structure 10 a giant gantry crane 20 (Figures 2 to 5) is employed. This comprises two supporting columns 21 and 22 and a girder 23. Each of the supporting columns comprises a pair of towers 24, 25 and 26, 27, respectively, spacing girders 28 and 29 between the bottoms of each. pair of towers, and cross beams 30 and 31 at the tops of each pair of towers. Each tower is mounted on a wheeled or tracked bogie 32 which is movable on rails or prepared trackways 33 beside the area 12.

The towers are connected by pin joints 34 to the bogies 32, to facilitate erection of the crane and adjustment of the vertical positioning of the supporting columns. The cross beams 30 and 31 are connected to the tops of the towers by pin joints 35, also to facilitate erection of the crane. The towers 24-27 are built up from braced sections which are bolted together end to end on the site, in the manner of conventional tower cranes. The girder 23 is also built up from braced sections bolted together, but as can best be seen in Figures 2, 4 and 5 there are front sections 36 and rear sections 37, the forward sections 36 being narrower than the rear sections 37. The front sections 36 are provided with tracks or rails 38 supporting a crab 39 with lifting gear 40. The crab 39 is movable along these rails for the whole length of the girder 23. A monorail 41 is provided at the rear of the sections 37, which supports movable lifting equipment 42. The ends of the girder 23 project outwards beyond the supporting columns 21 and 22 so that when the crab 39 or the lifting equipment 42 is moved to either end of the girder its hook or other load-supporting device can be lowered to pick up structural elements or constructional materials from beside the rails or trackways 33 on which the crane is supported, and lift and carry these elements or materials to the point of use between the supporting columns.

The crane has a forward working bay 70 served by the crab 39 and a rear working bay 71 served by the lifting equipment 42.

The crane can be erected by assembling the towers on the bogies on the site, these being held vertical by temporary struts 45 equipped with adjusting devices 46 (Figure 2). The girder 23 can be erected in two halves in a vertical position, one half on each side of the area 12, between the respective towers 24, 25 and 26, 27. The cross beams 30 and 31 are attached to the girder halves, in a position turned through 90° from that in which they are shown in the drawings, and joined to the tops of the respective towers by only one set of the pin joints 35. The halves of the girder are then swung up to a horizontal position, with the cross beams pivoting on the towers about the already fitted pin joints 35. The struts 4 are adjusted to hold the towers somewhat outwardly from the vertical until the two inner ends of the girder halves are properly aligned. The adjusting devices 46 are then eased to allow the said two ends to meet so that they can be "bolted together. The remaining pin joints 35 are then fitted.

Attached to the front lower "beam 49 of the girder 23, near the front crab rail 38, is a set of hangers 50.

These are termed herein permanent hangers because they can remain in place throughout the erection of the structure 10 in contrast to displaceable hangers 51 and 52 referred to below.The permanent hangers 50 may be rigid tubes, for example.

Attached to another lower beam 53 of the girder 23, near the rear crab rail 38, is a first set of displaceable hangers 51, while attached to a lower beam 54 of the girder 23 intermediate between the beam 53 and the monorail 41 is a second set of displaceable hangers 52.

Suspended from the hangers 50, 51 and 52 is a platform 55. This platform is shaped and disposed so as to lie just beneath the bridge-like sub-structures 11 and to span the area 12 from side to side. As best seen in Figures 4 and 5, the platform is long enough to extend beneath three sub-structures, in the case illustrated in these Figures the sub-structures lid, lie and llf. The forward end of the platform is somewhat ahead of the set of permanent hangers 50 which are attached to the platform by suitable fasteners 56.

In contrast, the rear portion of the platform extends for some distance beyond the second set of temporary hangers 52, and to assist in supporting this portion of the platform the rear two lid and lie, of the three sub-structures overlying the platform are provided temporarily with rollers 57 and 58, respectively, which engage longitudinal members 59 of the platform (Figure 5) . The temporary hangers 51 and 52 are attached to the platform "by releasable fasteners 61 and 62, respectively, and these hangers also include jacks or tensioning devices 63 and 64, respectively.

The method of using the crane will now he described, let it be assumed that starting from the left or far end of the structure 10 in Figure 1, the structure has been erected and provided with load-supporting flooring 13 as far as ihe sub-structure lid. The adjacent sub-structure lie has been erected and braced against the sub-structure lid by temporary stabilising beams 66 (Figure 5). The next sub-structure llf is in the course of erection. The crane is in the position in which it is shown in Figures 4 and 5.

The platform 55 lies beneath the two completed substructures lid, lie and beneath the foremost substructure llf which is in course of erection. There is no need for the platform to extend any further back than the sub-structure lid because the load-supporting floor 13 is already in place behind this sub-structure. Between sub-structures lid and lie, however, the platform 55 is necessary so that work can be carried out between these sub-structures, e.g. for the construction of a section of load-supporting flooring 13a between them, without risk of any articles or material falling into the area 12. This work is carried out with the aid of the lifting equipment 42 in the rear hay 71 of the crane. The sub-structure llf is erected in the front bay 70 of the crane with the aid of the crab 39 and its lifting gear 40. The platform also underlies the front bay 70. In the front bay 70, structural elements 72 for the substructure llf are hoisted into position by the crab 39 and its lifting gear 40, aligned and then jointed. In the rear bay 71, units to form the floor 13a are placed between the sub-structures lid and lie, whereupon the temporary stabilising beams 66 are removed. Wall units are also erected in this bay. In the front bay 70, stressing cables are threaded and joints cured in the sub-structure llf, and after curing the cables are stressed. The construction work may continue simultaneously in the rear bay.

Next, the temporary stabilising beams 66 are placed between the sub-structure lie, now stabilised by permanent connexion to the sub-structure lid on completion of the floor 13a, and the newly completed sub-structure llf, and the construction work in the rear bay 71 is completed. The crane now has to be moved forwards by a distance equal to the spacing of the sub-structures so that the next sub-structure llg can be erected and flooring and other work can be carried on between the sub-structures llje and llf. This forward movement of the crane is accomplished as follows.

The jacks 63 for the first set of displaceable hangers 51 are slacked off and the fasteners 61 at the lower ends of these hangers are released. These hangers can now be hitched up to clear the substructure llf as the crane is moved forward along the rails or trackways 33. When the hangers 51 have passed over the sub-structure llf, but before the second row of displaceable hangers 52 have reached the sub-structure llf the fasteners 61 are re-connected and the jacks 63 tightened to tension the hangers 51. Also, the jacks 64 for the second set of displaceable hangers 52 are slacked off, the fasteners 62 are released and the hangers 52 are hitched up to clear the sub-structure llf as the crane is moved further forward to its new working position. The rollers 58 which supported the rear portion of the platform 55 on the sub-structure lid may be removed when the platform has moved away from these rollers, and they are then fitted to the sub-structure llf.

The displaceable hangers 51 and 52 need not be cables, as so far described. For example, they may consist of upright lattice panels each having a foldable hinged portion which can be swung out of the way of the sub-structures as the crane is being moved forward, or each of the panels could have a separate removable portion which is bolted in place when the crane is in a working position.

The girder 23 may be given an upward camber in its unloaded condition, such that when it is under load it is straight and horizontal.

There may be pin joints 68 near the tops of the towers of one of the supporting columns to prevent flexure of the girder 23 imposing bending forces on the columns (see Figure 3).

Claims (8)

CLAIMS HAt-iS-tLAlMEE) -¾t — - - -

1. A movable gantry crane useful in the erection of a structure comprising several bridge-like substructures arranged side by side in spaced relationship; which crane comprises a girder long enough to span the structure, supported by movable supporting columns, at least two sets of hangers which suspend a platform from the girder in a position to lie beneath a bridge-like sub-structure to be erected with the aid of the crane, at least one set being disposed to occupy a position in front of the said sub-structure and at least one other set being disposed to occupy a position to the rear of the said sub-structure, a lifting device movable along the girder between sets of hangers disposed to occupy positions respectively in front of and to the rear of the said sub-structure, and the hangers of the said other set or sets being removable or displaceable to permit the crane including the platform to be moved forwards when this sub-structure has been made self-supporting and laterally stable.

2. A gantry crane as claimed in Claim 1 in which there is one set ox hangers disposed to occupy a position in front of the said sub-structure and two sets of removable or displaceable hangers disposed to occupy positions to the rear of the said sub-structure at different distances therefrom. . '

3. A gantry crane as claimed in Claim 1 or Claim 2 in which there is another lifting device movable along the girder to the rear of the set or sets of removable or displaceable hangers.

4. A gantry crane as claimed in any of the preceding Claims in which the platform is long enoiigh to encompass three sub-structures.

5. A gantry crane as claimed in Claim 5 and in Claim 4 which has a forward working bay served by the first-mentioned movable lifting device and rear working bay served by the said other movable lifting device.

6. A gantry crane as claimed in Claim 4 or

7. Claim 5 in which the platform is adapted to co-operate with roller supports therefor mounted on at least one of the sub-structures which is in a self-supporting, and laterally stable condition. - '7· A gantry crane as claimed in any of the preceding Claims in which at least one end of the girder projects beyond the respective supporting column. .

8. A gantry crane substantially as described with reference to the accompanying drawings. P. 0. Box 33116 Tel- A v i v