GB2058704A

GB2058704A - Overhead travelling crane

Info

Publication number: GB2058704A
Application number: GB8030132A
Authority: GB
Original assignee: Kloeckner Becorit GmbH
Current assignee: Kloeckner Becorit GmbH
Priority date: 1979-09-29
Filing date: 1980-09-18
Publication date: 1981-04-15
Also published as: GB2058704B; DE2939686A1

Abstract

A moving beam for a monorail conveyor can support a load such that the load can be tilted not only about an axis perpendicular to the beam but also about an axis parallel to the beam i.e. sideways tipping of the load. The moving beam (1, 2) has at each end two chain sprockets (8) with chains (9) hanging down from the sprockets (8) for connection to the load to be carried. The other end of each of the four chains (9) is secured to a respective spindle nut (12) on a respective carriage (13) movable longitudinally of the beam (1, 2). A motor (15) drives a gear (16) and thus any one or more of four screw spindles (11) by way of selectively operable clutches (18) and brakes (19) thereby individually to raise or lower the chains (9). <IMAGE>

Description

SPECIFICATION Moving beam for a monorail conveyor The invention relates to a moving beam for a monorail conveyor particularly though not exclusively for use in underground mines.

Previously proposed moving beams of this kind have generally had two chains, each of which was provided at a respective end of the beam. At the lower ends of said chains hooks or other suspension means were provided by means of which the load could be suspended by means of the chains.

Such moving beams have the disadvantage that they are only suitable to a very limited extent to influence the position of the load suspended thereo. By selectively raising or lowering the chains located at the ends of the moving beam the load can only be raised, lowered or tilted about an axis at right angles to the longitudinal axis of the beam. However, in many cases it is desirable also to be able to tilt the load about an axis parallel to the longitudinal axis of the beam, so that the load can assume substantially any desired position. A tilting of the load about an axis parallel to the longitudinal axis of the moving beam is particularly important if the load comprises an elongate container suspended on the beam and to be emptied sideways without any special auxiliary means.

According to the invention there is provided a moving beam for a monorail conveyor having two motor-driven chains associated with each end of the moving beam jointly to carry the load, the two chains at each end of the moving beam being spaced apart from one another in a direction at right angles to the longitudinal axis of the moving beam, and the four chains of the moving beam being driveable individually, in pairs or in random groups.

In the case of the moving beam according to the invention it is possible by raising or lowering the two chains on one side of the load or the two chains on the other side of the load to tilt the load about an axis parallel to the longitudinal axis of the beam. It is naturally also possible to raise and lower the two front or the two rear chains, so that the load can be tilted about an axis at right angles to the longitudinal axis of the moving beam.

Finally it is also possible to operate the chains individually to bring the load into a desired tilting position. The moving beam according to the invention can consequently make it possible to bring a load suspended thereon into substantially any desired position.

Particular difficulties are encountered with the moving beam according to the invention through the necessity of providing four chain drives. The conventional chain drives with a rotatable chain drum or drives by means of pressure cylinders running parallel to the moving beam require a relatively large amount of space and consequently constrict the already limited area between the bottom of the moving beam and the base.

Advantageously the four chains are each driveable by a respective screw spindle, the four screw spindles extend parallel to the longitudinal axis of the moving beam and can be driven in dividually, in pair or in random groups and a respective spindle nut for each spindle is guided in longitudinally displaceable manner on the movinq beam and has the end of a respective one of the chains fixed thereto. This can be a particularly space-saving construction.

Preferably each spindle nut is located with respect to a respective travelling carriage guided by means of runners on rails of the moving beam.

This can ensure that the spindle nuts of the chain drives are kept free from unfavourable loading effects. The travelling carriages guided on the rails by means of rollers support the torques caused by the eccentric engagement of the chains, so that the screw spindle gears do not have to support these torques.

Preferably the moving beam includes a gearing end frame provided at one end of the moving beam and mounting a drive motor, a motor driven gear to drive four parallel driven shafts, each aligned with a respective one of the screw spindles, and four clutches arranged in each case between one of the driven shafts and the respective screw spindles, which four clutches can be operates individually, in pairs or in random groups.

To prevent automatic lowering of the chains under the influence of the load the screw spindles and the associated spindle nuts preferably have such a flat pitch that they have a self-locking action.

In order to be able reliably to secure the load carried by the moving beam even in the case of vibrations, for example caused by the beam moving along the rail, a brake can be associated with each screw spindle to prevent that screw spindle from performing undesired rotary movements.

The moving beam advantageously includes a control block which is able to control the functions of the motor, the clutches and the brakes.

The moving beam may be so arranged that the downwardly hanging ends of the chains at each end of the moving beam are inter-connected and the thus formed chain strand is guided around a chain wheel secured on the end face of a container with the axis of the chain wheel located approximately level with the centre of gravity of the container. This makes it possible gradually to empty the container sideways in a controlled manner, without the container turning over in an uncontrolled manner just before reaching the end position, as is the case with most conventional tipping containers suspended on a monorail conveyor.

The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which: Figure 1 is a side view of a moving beam according to the invention; Figure 2 is a plan view of the moving beam of Figure 1; and Figure 3 is a front view of a container suspended on a moving beam according to the invention.

Referring to the drawings, a moving beam has two spaced longitudinal girders 1 and 2, which are substantially constructed as hollow boxes which are partly open at the top. The ends of the two longitudinal girders 1 and 2 are interconnected by cross-members 3, 4. The cross-members 3, 4 are suspended on a monorail conveyor 7 by means of bogies 5 and 6 which engage in articulated manner thereon.

Two sprocket wheels 8 are provided adjacent each end of the two longitudinal girders 1, 2. The four sprocket wheels 8 are in each case mounted in the longitudinal girders so as to be rotatable about horizontal axes extending at right angles to the longitudinal axis of the moving beam. Chains 9 extend over the sprocket wheels 8 and each chain 9 hangs vertically downwards beyond the sprocket wheel 8. In the embodiment of Figures 1 and 2 hooks 10 for the suspension of a load are provided at the ends of the vertically directed portions of chains 9.

Four screw spindles 11 mounted in the longitudinal girders 1, 2 and extending parallel to the longitudinal axis of the moving beam serve to drive the four sprocket wheels for the four chains 9. The four screw spindles 11 each engage with a respective spindle nut 12. The spindle nuts 12 are prevented from rotating and are each provided on a respective travelling carriage 1 w3 movable along the longitudinal girders 1 , 2. The carriages 13 are guided by means of runners on the rails associated with longituindal girders 1 , 2. The upper end of each chain 9 is fixed to a respective one of the four travelling carraiges 13.

The screw spindles 11 can be driven by a gearing end frame 14 which is fixed to one end face of the girders 1 and 2. The gearing end frame 14 mounts a preferably hydraulically or pneumatically driven motor 1 5, a gear 1 6 on the shaftofthe motor 15 and four driven shafts 17.

Each of the shafts 1 7 is aligned with a respective one of the screw spindles 11. Clutches 18, operable individually, in pairs or in random groupings are located between the driven shafts 1 7 and the screw spindles 11.

The screw spindles 11 and the associated nuts 12 have such a flat pitch that the nuts 1 7 are selflocking on the screw spindles 11, so that the nuts 12 cannot be moved by a force applied to the chains 9. Additionally to secure against an undesired lowering of the load, even in the case of vibrations or the like a brake 1 9 is associated with each screw spindle 11 but is released as soon as the associated clutch 18 is engaged.

The moving beam also has a control block 20 which is suspended from a tie rod 21 which couples the moving beam to an adjacent moving beam. The motor 15, clutches 1 8 and brakes 1 9 are controllable by controls on the control block 20 to raise or lower individually any one of the four corners of a load to which the chains are connected by the four hooks 1 0.

In the embodiment of Figure 3, the downwardly hanging ends of the chains 9 are interconnected at each end of the moving beam. The thus formed chain loop is guided round a chain wheel 22 firmly connected to the respective end face of a load container 23, the axis of the chain wheel 22 being approximately located level with the centre of gravity of the container 23. If the chains 9 are extended or retracted, as indicated by the arrows in Figure 3, the container is pivoted about its longitudinal axis, being controlled in each phase of the pivotal movement by the movements of the chains 9.

Claims

1. A moving beam for a monorail conveyor having two motor-driven chains associated with each end of the moving beam jointly to carry the load, thevtwo chains at each end of the moving beam being spaced apart from one another in a direction at right angles to the longitudinal axis of the moving beam, and the four chains of the moving beam being driveable individually, in pairs or in random groups.

2. A moving beam according to claim 1, in which the four chains are each driveable by a respective screw spindle, the four screw spindles extend parallel to the longitudinal axis of the moving beam and can be driven individually, in pairs or in random groups and a respective spindle nut for each spindle is guided in longitudinally displaceable manner on the moving beam and has the end of a respective one of the chains fixed thereto.

3. A moving beam according to claim 2, in which each spindle nut is located with respect to a respective travelling carriage guided by means of runners on rails of the moving beam.

4. A moving beam according to claim 2 or claim 3, including a gearing end frame provided at one end of the moving beam and mounting a drive motor, a motor driven gear to drive four parallel driven shafts, each aligned with a respective one of the screw spindles, and four clutches arranged in each case between one of the driven shafts and the respective screw spindles, which four clutches can be operated individually, in pairs or in random groups.

5. A moving beam according to any one of claims 2 to 4, in which the screw spindles and the associated spindle nuts have such a flat pitch that they have a self-locking action.

6. A moving beam according to any one of claims 2 to 5, including a brake associated with each screw spindle to prevent that screw spindle from performing undesired rotary movements.

7. A moving beam according to claim 6, including a control block which is able to control the functions of the motor, the clutches and the brakes.

8. A moving beam according to any one of claims 1 to 7, in which the downwardly hanging ends of the chains at each end of the moving beam are interconnected and the thus formed chain strand is guided around a chain wheel secured on the end face of a container with the axis of the chain wheel located approximately level with the centre of gravity of the container.

9. A moving beam for a monorail container substantially as hereinbefore described and illustrated with reference to any of the accompanying drawings.