IE47391B1 - A crane installation,in particular for use in the engine room of a ship - Google Patents

Abstract

A crane installation, in particular for use in rooms in which the floor-to- ceiling height is locally reduced by beams 5 supporting an overlying deck 4, comprises a carriage 7 travelling on rails 6 below the beams and a trolley 12 travelling on rails provided in the carriage in a direction perpendicular to the travelling direction of the carriage. The trolley is U-shaped in plan view with two parallel legs and a connecting cross member, and a jib 23 is supported in the trolley for pivoting on an axis perpendicular to the two legs of the trolley. A lifting means 27 is suspended in a cable depending from the free end of the jib. In the areas between the deck beams the jib can be pivoted above the level of the undersides of the beams whereby the increased floor-to-ceiling height can be utilized in these areas for lifting and lowering a load and transporting the load laterally.

Description

The present invention relates to a crane installation, in particular for use in the engine room of a ship, and comprising a carriage adapted to travel along a set of longitudinal rails suspended from beams supporting an over5 lying deck, a trolley adapted to travel along a set of transverse rails belonging to the carriage, and a hoisting device mounted in the trolley and comprising a lifting means vzhich can be raised and lowered by means of a lifting cable.

In known installations of the kind referred to the hoisting device is mounted in a trolley which in plan view is shaped as a closed rectangular framework v/ith supporting wheels adjacent the four corners of the framework, and the hoisting device comprises a drum journalled in the trolley and adapted to accommodate the lifting cable from the free end of which the lifting means, e.g. a hook or a lifting magnet, is suspended.

As used in the present specification and claims the term lifting cable is used to designate any suitable flexible load carrying element including steel wires, ropes of natural or man-made fiber materials and chains. It should also be noted that the definition of the two sets of rails as being longitudinal and transverse, respectively, is related only to the mutual orientation of the rails and, hence, of the directions in which the carriage and the trolley can travel. It does not imply any restriction in respect of the orientation of the rails relative to the longitudinal and transverse direction of the ship or gene4 7 3 91 - 3 rally the room in which the installation is mounted.

According to the present invention there is provided a crane installation comprising in combination: longitudinal rails adapted to be suspended from beams supporting an overlying deck, a carriage for travelling along said longitudinal rails and comprising transverse rails, a trolley for travelling along said transverse rails, said trolley being U-shaped, when viewed in plan, and comprising two legs parallel with said transverse rails and a cross member connecting said legs, a jib journalled on the cross member of said trolley for pivoting between the parallel legs thereof about a horizontal axis parallel to said cross member, and a mechanism coupled to said jib for pivoting it about said axis, and a hoisting device mounted on said trolley and comprising a lifting cable depending from the free end of said jib and a lifting means at the end of said lifting cable.

Whereas the maximum lifting height of the known crane installations referred to above is determined by the location of the cable drum, the invention provides for an upwardly increased lifting height in those working areas which are located between two adjacent deck beams and in which the jib can therefore be pivoted upwardly to the limit defined by the overlying deck. In those areas the lifting means can be raised above the level of the carriage and the longitudinal rails, whereby the u-shape of the trolley ensures that an article or load suspended from the lifting means does not collide with the trolley. After the 7 3 9 1 - 4 jib has been pivoted upwardly it is then possible, within said working areas, to utilize the full height below the deck for vertically lifting and/or lowering a load or article. In the lowered position of the jib, in which it clears the undersurface of the deck beams, it may be located entirely within the vertical extension of the carriage so that only a minimum of vertical clearance is necessary between the lowermost part of the carriage and the engine or other apparatus which is to be serviced by the crane installation. The U-shape of the trolley permits the suspended article or load to extend laterally beyond the free ends of the trolley's parallel legs which consequently can be relatively short. With a given spacing between the longitudinal rails this permits a correspondingly longer transverse travel of the trolley with a load suspended therefrom, resulting in an increase of the area in which the lifting means can operate. The invention is particularly advantageous in the so-called Ro-Ro ships in which it is essential to keep the floor-to-ceiling height of the engine room as low as possible in order to obtain maximum payload volume, while at the same time the load on the deck dictates the use of rather high beams for supporting the deck which effectively forms the ceiling of the engine room.

In a first embodiment of the present invention the hoisting device comprises a drum for accommodating the lifting cable, said drum being journalled, by means of bearings rigidly connected with said jib, for rotation about an axis parallel with the pivot axis of the jib, which pivot axis is located outside the drum. In this embodiment the angle, at which the cable extends from the drum, remains unchanged during a pivoting movement <£ the jib, and the bearings, in which the jib is journalled on the trolley, can be arranged with a rather close spacing shorter than the length of the 3 91 - 5 cable drum with the associated drive mechanism.

By locating the pivot axis of the jib behind the drum axis when viewed from the free end of the jib, and at a higher level than the drum axis, it is obtained that in its raised position the jib forms a relatively small angle with the horizontal. This increases the height to which articles with large lateral dimensions can be raised without bumping against the jib.

In an alternative embodiment the hoisting device is a self-contained hoist suspended at the free end of the jib. In this embodiment the width of the end of the jib, which is journalled on the trolley, can be reduced, which permits a longer travel of the carriage between adjacent deck beans with the jib in raised position.

Since, as mentioned above, the increased lifting height is available only within limited areas defined between adjacent deck beams, the installation may include a safety mechanism for restricting the travel of the carriage on the longitudinal rails when the jib is in a raised position. Within each of said areas it is then possible to utilize the maximum lifting height without limitations while the carriage with or without a suspended load can travel longitudinally below the deck beams only when the jib has been lowered to a position below the undersurface of the beams.

The invention will now be described in more detail with reference to the accompanying, rather schematical drawings in which Fig. 1 is a cross-section through the engine room of a ship in which there is providedi a crane installation embodying the present invention for carrying out overhauling procedures on the engine of the ship, - 6 Fig. 2 is a vertical view, on a larger scale, of the crane installation proper.

Fig. 3 is a plan view of Fig. 2, and Fig. 4 is a fractional view corresponding to Fig.2 and on a still larger scale, showing a crane installation with a self-contained hoist suspended from the jib.

In Fig. 1 the plating forming the hull of the ship is indicated at 1 while reference numeral 2 generally designates a diesel engine mounted in the engine room 3, the ceiling of which is formed by a car deck 4. The car deck is supported by transverse deck beams 5 with the mutual spacing of adjacent beams, in the longitudinal direction of the ship, being equal to or approximately equal to the cylinder distance of engine 2 or a multiple thereof, so that each beam 5 is located between two engine cylinders.

To the undersurfaces of deck beams 5 are secured two longitudinal I-beans 6 which serve as supporting rails for a travelling carriage generally designated by 7 and comprising a rectangular framework having longitudinal beams 8 and transverse or cross beams 9. The carriage is supported by wheels 10, which are journalled in beams 8, and it is displaced longitudinally on rails 6 by means of pinions driven by motors 11 and engaging in gear racks secured below rails 6.

The transverse beams 9 of the carriage serve as supporting rails for a travelling trolley generally designated by 12. The trolley comprises a frame, which in plan view is U-shaped, and comprising two parallel beams or legs 13 in which the supporting wheels 14 of the trolley are journalled, and a cross member 15 connecting the legs 13 at one end thereof. The trolley is displaced along the transverse beams or rails 9 by means of a motor 15 which drives 39 1 - 7 two pinions engaging with racks secured belcw the rails.

Two brackets 17 extend upwardly from cross member 15 and by means of horizontal and aligned pivot pins 18, a unit 19, which will be described in more detail below, is pivotally journalled in the brackets. Unit 19 comprises two housings 20 anc1 21, which contain bearings for the cable drum 22 of the crane and the associated drive motor which can be built into the drum proper, and a jib 23 extending perpendicular to the pivot axis. As best shown in Fig. 3, the inner end of jib 23 is secured to the bearing housings 20 and 21. The lifting cable 24 of the crane extends from cable drum 22 around a guide or idler pulley 25, which is journalled at the free end of jib 23, through a block 26, in which the crane hook 27 is mounted, and across a further guide pulley 28 back to jib 23 to which one end of the cable is secured.

One end of a hydraulic ram 29 is pivotally connected to trolley 12 and the protruding end of the associated piston rod 30 is pivotally connected to jib 23 intermediate the ends thereof. Through a valve system (not shown) ram 29 is supplied from an oil pump 31 which together with the associated drive motor 32 is mounted on trolley 12. By means of ram 29 jib 23, from which the crane hook 27 depends, can be pivoted between two end positions shown in Fig. 2, i.e. from a horizontal position shown in full lines, in which the jib and hence the entire unit 19 clears the undersurface of deck beams 5, to a raised position shown in dot-and-dash lines in which the uppermost point of the unit 19 is located immediately below deck 4.

It will be appreciated that the pivoting movement of unit 19 could alternatively be effected by means of a pneumatic ram or a suitable mechanical device.

With the crane installation described it is possible to carry out overhauling of engine 2, especially dismantling and replacement of pistons and cylinder liners even if the lifting height available below the undersurfaces of deck beams 5 is insufficient to bring the component parts in question clear of the engine. For carrying out such an overhaul procedure motors 11 are first operated to bring carriage 7, with unit 19 in horizontal position, to a position above the engine cylinder in question. Since, as explained above, the vertical center line of the engine cylinder is located between two deck beams 5, it is possible, before or after attaching the engine component in question to the hook, to pivot unit 19 including jib 23 to the raised position shown in Fig. 2 and thus to obtain the necessary increase of the lifting height so that the engine component can be withdrawn and subsequently moved laterally away from engine 2 by a transverse displacement of trolley 12 relative to carriage 7. The engine component can subsequently be lowered directly to a working position as indicated at the left of Fig. 1, which shows an engine piston 33 with associated piston rod 34 deposited in a tubular support 35 on one of the platforms of engine 2. Alternatively it would be possible, after a transverse displacement of trolley 12 with the suspended engine component, to lower unit 19 to a horizontal position followed by a longitudinal displacement of the entire carriage 7, which brings the component to a different working position spaced from the engine cylinder.

The previously mentioned safety mechanism intended to prevent the crane from colliding with a deck beam 5 by restricting the possible longitudinal travel of carriage 7 may include a switch mounted in trolley 12 and arranged for being actuated by unit 19 when jib 23 is lifted, to interrupt the current supply to motors 11, at least when unit 19 is located close to a deck beam 5. It may also be expedient to include a safety mechanism which permits raising of unit 19 only when this uni1·- is spaced a safe distance from a beam .

The embodiment illustrated in Fig. 4 deviates only from that shown in Figs. 2 and 3 by the design of the jib and the hoisting device. The other component parts of the crane installation may be identical with those described above, and parts thereof shown in Fig. 4 have been given the same reference numerals.

By means of two horizontally aligned pivot pins 18 the jib, which in Fig. 4 is designated by 40, is - like unit 19 - pivotally journalled in two brackets 17 secured to and extending upwardly from the cross member 15 of the trolley. For pivoting the jib there is provided a ram 29, one end of which is connected to cross member 15 while the free end of the piston rod 30 of the ram is pivotally connected with the jib intermediate the ends thereof. At the free end of jib 40, a self-contained hoist 41, e.g. an electro hoist, with associated crane hook 42 is suspended by means of a horizontal pivot pin 43.

The crane may comprise two pivoting jibs, each provided with a hoist or cable drum. The jibs may be designed to be used either individually or connected together, e.g. for lifting an engine piston by means of a tool designed for engaging below the piston skirt and for being supported by two hooks each suspended from one of the jibs.

It will also be appreciated that the drive motors for effecting travel of the carriage and the trolley may be hydraulic motors rather than electric motors as shown.

While the invention has been described in connection with a crane installation in a ship's engine room, it will be appreciated that similar crane installations may also be - 10 employed in other places in which similar conditions pre vail, e.g. in factory buildings and assembly shops.

Claims (7)

1. CLAIMS :1. A crane installation, in particular for use in the engine room of a ship, comprising in combination: longitudinal rails adapted to be suspended from beams supporting an overlying deck, a carriage for travelling along said longitudinal rails and comprising transverse rails, a trolley for travelling along said transverse rails, said trolley being U-shaped, when viewed in plan, and comprising two legs parallel with said transverse rails and a cross member connecting said legs, a jib journalled on the cross member of said trolley for pivoting between said parallel legs about a horizontal axis parallel to said cross member, and a mechanism coupled to said jib for pivoting it about said axis, and a hoisting device mounted on said trolley and comprising a lifting cable depending from the free end of said jib and a lifting means at the end of said lifting cable.

2. A crane installation as claimed in claim 1, wherein the hoisting device comprises a drum for accommodating said lifting cable, said drum being journalled, by means of bearings rigidly connected with said jib, for rotation about an axis parallel with the pivot axis of the jib, which pivot axis is located outside the drum.

3. A crane installation as claimed in claim 2 wherein the pivot axis of the jib is located behind the drum axis, when viewed from the free end of the jib, and at a higher level than the drum axis.

4. A crane installation as claimed in claim 1, wherein said hoisting device is a self-contained hoist suspended at - 12 the free end of the jib.

5. A crane installation as claimed in any of claims 1 to 4, wherein the mechanism for pivoting the jib comprises a fluid ram connecting the trolley with a point of the jib 5 intermediate the ends thereof.

6. A crane installation as claimed in any of claims 1 to 5, further comprising a safety mechanism for restricting the travel of the carriage on the longitudinal rails when the jib is in a raised position.

7. 10 7. A crane installation, substantially as described and illustrated in the accompanying drawings.