GB2167379A

GB2167379A - Jib system for cranes, particularly for railway cranes

Info

Publication number: GB2167379A
Application number: GB08527553A
Authority: GB
Inventors: Horst Bendix; Eberhard Heinig; Horst Richter; Gunther Gasteier; Theo Kallenbach
Original assignee: MAN Takraf Fordertechnik GmbH
Current assignee: Takraf GmbH
Priority date: 1984-11-21
Filing date: 1985-11-08
Publication date: 1986-05-29
Also published as: DD229101A1; DE3531250A1; GB2167379B; GB8527553D0

Abstract

A jib system can be used in a horizontal or slightly tilted mode (Fig. 1) and in a steeply inclined position (Fig. 4): conversion of the jib system from one mode to the other being achieved with means present on the lifting equipment. The jib system comprises a telescopic upper jib portion 1 pivotally connected at 15 to a non-telescopic lower jib portion 2 which is pivoted to the crane structure 7 at 14. Differential traction means provides for conversion of the jib into a steeply inclined jib. In the Fig. 1 position the upper telescopic jib portion 1 is luffed about the pivot 15 by cylinders 4. The jib is extended to the Fig. 4 position by extension of cylinders 9 the upper and lower jib portions 1 and 2 being aligned about the pivot 15 by a traction element 10, a support 3 enabling a cable block arrangement 6 to luff the jib, (locked in the straightened position by securing elements 18). <IMAGE>

Description

SPECIFICATION Jib system for cranes, particularly for railway cranes The invention relates to a jib system for cranes, in particular for railway cranes. It can be used both on cranes which are capable of moving in position freely from place to place and also lifting equipment in which it is important to have universal forms of use of the jib.

Cranes, in particular railway cranes, are known, in which the jib is arranged movably at the front part of the upper portion of the crane, for use in a steep or inclined position.

In that arrangement, high heights of lift are still achieved, with heavy loads. Such cranes are particularly suitable for transferring loads, for service in remedying damage to ships or cargo, for use in industry and for assembly operations, but they are not suitable for use under catenary or trolley lines and tunnels.

There is the further disadvantage that, on transportation of the crane, the jib must be set down on an additional jib support truck or carriage.

Also known are railway cranes with a telescopic jib, which also have their maximum load carying capacity when the jib is in a horizontal position. A disadvantage with that arrangement is that only small heights of lift are achieved with heavy loads.

A further jib system in a construction crane is known, comprising a vertically upright lower jib portion on which further adjustable upper jib portions are arranged, being pivotally mounted thereto. A disadvantage with that construction is that a complicated block and holding system is required for moving the jibs and the jib system generally cannot be inclined and thus only low loads are achieved, at high heights of lift (French patent specification No. 74045 15).

The invention is based on the problem of developing a jib system which can be operatively loaded in a horizontal or in a steeply inclined position of the jib and the operability of which can be achieved with means which are substantially present on the crane. In that connection, the invention seeks to provide that maximum technical parameters such as for example maximum load carrying forces, large ranges in regard to cantilever length of action and large heights of lift are achieved.

The invention seeks to provide that, in the transportation condition, the jib length remains within the vehicle length.

According to the present invention there is provided a jib system for a crane, such as railway cranes, comprising a non-telescopic lower jib portion which is pivotably mounted on the upper part of the crane and at the free end of which a telescopic upper jib portion is pivotally arranged, wherein supports, a cable block arrangement and holding cables are arranged between the upper part of the crane and the jib system, the tiltable and telescopically movable upper jib portion being con- nected by way of a pivot to the non-telescopically movable lower jib portion so that the upper jib portion can be laid down on the lower jib portion in opposite relationship to the lower jib portion and the upper jib portion can be used either as a horizontally disposed and tiltable telescopic jib or in conjunction with the lower jib portion as an elongate retractable and extensible jib.

Provided between the upper part of the crane and the upper jib portion are hydraulic operating cylinders which can be released on the upper jib portion, for tilting thereof.

Hydraulic operating cylinders between the upper part of the crane and the lower jib portion, by way of a differential traction means which comprises traction elements, directionchanging rollers and pivot points, wherein the traction elements are disposed between the upper jib portion and the upper part of the crane, provide for straigthening up the two portions of the jib into an elongated jib structure in which the axes of symmetry of the two jib portions is disposed in the line of interpenetration of two planes which cross each other at a right angle.

The combination of the two jib arrangements, in accordance with the invention, provides that the jib system can be used either as a telescopic and tiltable telescopic jib or as a retractable and extensible high-angle jib and maximum load carrying forces, heights of lift and ranges of length of action of the jib are attained in each jib arrangement.

An embodiment of the invention will now be described, by way of an example, with reference to the accompanying drawings, in which: Figure 1 is a view of the jib system in a horizontal position; Figure 2 is a view of the jib system in the elongated steeply inclined position; Figure 3 is a view of the straightening-up system in the horizontal position of the jib system; and Figure 4 is a view of the straightening-up system in the elongated position of the jib system.

As shown in Figs. 1 and 2, the jib system comprises a telescopic upper jib portion 1, a non-telescopic lower jib portion 2, a support 3, the tilting cylinders 4, a holding cable 5 and a cable block arrangement 6.

As shown in Figs. 3 and 4, disposed between the lower jib portion 2 and the upper part 7 of the crane is a differential traction means 8. As shown in Figs. 3 and 4, the differential traction means 8 comprises the hydraulic operating cylinders 9, the traction element 10, the fixing points 11 on the upper part 7 of the crane, the direction-changing point 12 and the fixing point 13 on the upper jib portion 1.

In the transportation position which at the same time represents the starting position for the horizontal or tilted operating position of the jib system, the lower jib portion 2 which, as shown in Figs. 1 and 2, is connected by the mounting 14 to the upper part 7 of the crane and by way of the pivot 15 to the upper jib portion 1, is laid down on the upper part 7 of the crane in opposite relationship to the upper jib portion 1. The jib system can be used as a telescopic jib 16 from the aboveindicated starting position of the jib system, by telescopically extending and/or tilting the jib system.

The differential traction means 8, the support 3, the holding cable 5 and the cable block arrangement 6 are in the rest position in that condition.

In that operating portion, the rotary railway crane operates with its telescopic jib 16 for example under bridges, catenary or overhead lines and in tunnels or by extension of the tilting cylinders 4, at greater heights of lift.

The entire jib system is straightened out for the crane to be used with high loads to be lifted and for achieving high heights of lift and substantial lengths of action of the jib. With the jib system in that position, the rotary railway crane operates like a crane with a retractable and extensible elongated jib 17 arranged on the head portion of the upper part 7 of the crane (see Fig. 2).

As shown in Figs. 3 and 4, the differential traction means 8 is used for straightening up the jib system. The hydraulic operating cylinders 9 are extended and tension the traction elements 10, for example wire cables. They are each disposed at a fixing point 11 on the upper part 7 of the crane and by way of a direction-changing point 12 at a fixing point 13 on the upper portion 1 of the jib 1, in such a way that upon further extension of the hydraulic operating cylinder 9, the two jib portions 1 and 2 move about the pivot 15 and are drawn into an elongate or extended jib position. In that position of the jib, the two portions 1 and 2 of the jib are locked by securing elements 18. The tilting cylinders 4 are released before the upper jib portion 1 is straightened out. The hydraulic operating cylinders 9 are retracted after the jib system has been straightened out. Extension and retraction of the two locked jib portions 1 and 2 is effected by varying the cable block arrangement 6 by way of the support 3 and the holding cable 5. The holding cable 5 is disposed between the support 3 and the upper free end of the basic telescopic means 19.

With such an arrangement of the jib system the advantages of a telescopic jib which is operable horizontally and in a tilted condition are combined with the advantages of a retractable and extensible elongated jib.

Claims

1. A jib system for a crane, such as railway cranes, comprising a non-telescopic lower jib portion which is pivotably mounted on the upper part of the crane and at the free end of which a telescopic upper jib portion is pivotally arranged, wherein supports, a cable block arrangement and holding cables are arranged between the upper part of the crane and the jib system, the tiltable and telescopically movable upper jib portion being connected by way of a pivot to the non-telescopically movable lower jib portion so that the upper jib portion can be laid down on the lower jib portion in opposite relationship to the lower jib portion and the upper jib portion can be used either as a horizontally disposed and tiltable jib or in conjunction with the lower jib portion as an elongate retractable and extensible jib.

2. A jib system as claimed in claim 1, in which the support, the cable block arrangement and the holding cable are arranged between the upper part of the crane and the free end of the telescopic movable upper jib portion.

3. A jib system as claimed in claim 1 or claim 2, in which a differential traction means is arranged between the upper part of the crane and the upper jib portion.

4. A jib system as claimed in claim 3, in which the differential traction means comprises operating cylinders which are disposed between the upper part of the crane and the lower jib portion, and traction elements which are disposed between fixing points on the upper part of the crane, direction-changing points and fixing points on the upper jib portion.

5. A jib system for a crane, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.