GB2195968A

GB2195968A - Endless hose conveyor

Info

Publication number: GB2195968A
Application number: GB08721987A
Authority: GB
Inventors: Friedrich Wilhelm Paurat; Roland Paurat
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-09-22
Filing date: 1987-09-18
Publication date: 1988-04-20
Anticipated expiration: 2007-09-18
Also published as: DE3632121C1; GB8721987D0; GB2195968B

Abstract

An endless hose conveyor for underground mine workings, traversing a forward run (10), a return run (7), a driving roll (6), and a reversal station (not shown), and having a conveyor belt (1) which can close to form a conveyor hose, trolleys (2) disposed on both long edges of the conveyor belt and running in guide rails (3), and a traction chain (5) attached to the base or keel of the conveyor belt when it is closed as a hose, has guide rails (3) diverge in the vicinity of the driving roll (6) disposed at the end of the forward run (10), so as to open the conveyor hose out into a flat belt configuration. According to the invention, there is provided a conveyor belt storage station (15) having portions of guide rails (3a) disposed at the spacing forming a flat belt, between which the conveyor belt (1) is festooned (16) in the direction of advance, the conveyor belt storage station (15) being disposed in the return run (7) and following on from the driving roll (6) or an intermediate driving roll (not shown) in the direction of conveyor belt advance. <IMAGE>

Description

SPECIFICATION Endless hose conveyor This invention relates to an endless hose conveyor traversing a forward run, a return run, a driving roll, and a reversal station, and having a conveyor belt which can close to form a conveyor hose, trolleys disposed on the two long edges of the conveyor belt and running along guide rails, a traction chain attached to the base or keel of the conveyor belt when it is closed as a hose, and optional intermediate driving rolls disposed in the lower run, in which the guide rails diverge at least in the vicinity of the driving roll disposed at the end of the forward run, so as to open the conveyor hose out into a flat belt configuration which lies against the driving roll and advances along with the traction chain also lying on the driving roll from the forward run into the return run.The hose conveyor is adapted in particular for use as a face conveyor in underground mine workings. The conveyor belt carries the traction forces from the traction cahin to the trolleys. It is self-evident that the driving roll has a central recess for the traction chain and can be there formed as a chain drum. Degrees of freedom in the traction chain and/or in the attachments between the trolleys and the conveyor belt and/or provided by deformations of the conveyor belt itself exclude the constraints at reversal points and the like which arise from path differences.

The guide rails are suitably directed to allow the conveyor belt to open and close so that the hose conveyor can be loaded and unloaded.

In a known hose conveyor (US-PS 3 978 976), any load-dependent extension of the traction chain is counteracted in the conventional manner by providing a tensioning roller in the lower run. As a result, the trolleys disposed on the long edges are only guided in the guide rails step by step. This stepwise interrupted guidance is open to improvement.

Moreover, the known devices provide only a limited compensation for length variations in the traction chain. More particularly, the known length compensation means are unsatisfactory in the very long hose conveyors typically required in face conveyors for underground mine workings.

The object of the invention is to modify and improve a hose conveyor of the type initially described so that length variations in the traction chain can be compensated over a very wide range and the trolleys remain guided by the guide rails over their entire path.

According to the present invention, there is provided a conveyor belt storage station having portions of guide rails disposed at the spacing forming a flat belt and between which the conveyor belt is festooned in the direction of advance, the conveyor belt storage station being disposed in the return run and following on from the driving roll or an intermediate driving roll in the direction of advance of the conveyor belt.

Thus, any surplus length of conveyor belting is stored like festoons in the conveyor belt storage station, and there the traction chain is disposed on the upper side of the conveyor belt. The storage capacity equals the number of festoons multiplied by the difference between the chain length between successive trolleys and the trolley spacing when a festoon is formed. The invention is based on the recognition that the chain tension immediately beyond a driving roll is low, and a small chain prestress is sufficient to keep the traction chain enmeshed in the driving unit. The invention makes use of the fact that the traction chain is guided on the conveyor belt.The surprising feature is that the chain is positively prevented from twisting, slipping or disengaging from the driving roll when the conveyor belt is festooned in accordance with the invention between the guide rails in the conveyor belt storage station.

The constructional embodiments of the device of the invention can take various forms.

One embodiment of outstandingly simple design and suitability for underground mine workings is characterised in that the guide rails in the conveyor belt storage station slope downwards in the direction of advance of the conveyor belt, at an angle sufficient to overcome the trolley roller resistance. The slope angle is adjusted so that the weight of the conveyor belt and chain maintain a tight loop round the driving unit. The trolleys spontaneously run down the sloping guide rails. At the end of the guide rails in the conveyor belt storage station the trolleys are halted and the conveyor belt folds up into a festoon. If an adequate sloop cannot be accommodated, the folding of the conveyor belt must be ensured by some mechanical means.In this event, the invention provides that a trolley driving attachment is provided on the guide rails in the conveyor belt storage station, so that the trolleys are impelled under an adjustable forward pushing force. The trolley driving attachment may take the form of an endless-loop transporter having coupling members for the trolleys. It is self-evident that a braking force must be applied to the trolleys on the conveyor belt as they leave the conveyor belt storage station. A suitable braking force can be applied by means characterised in that the guide rails leading out of the conveyor belt storage station are horizontal or slope upwards in the direction of advance of the conveyor belt.However, one embodiment of the invention provides that the guide rails in the conveyor belt storage station have a braking attachment aligned with the guide rails and applying and adjustable braking force which can be matched to the chain tension in the return run. Matching in this connection also covers the regulation and control of the traction chain tension in the return run. The installation of a braking device is always preferable when long surplus lengths of conveyor belting must be stored as festoons and/or -the stored surplus length is to be variable over a wide range. Conventional driving units can be used for the transmission of forces of the chain.

The traction chain is preferably passed round a driving roll of the start-wheel type with pointed teeth.

The accruing advantages are to be seen in that major variations in the length of the traction chain can be compensated. The length variations may arise as a result of either load variations or chain wear. In very long hose conveyors, wear can increase the chain length by 10 m or more. Furthermore, the invention offers the advantage that the length of the hose conveyor can be reduced and/or increased without manipulating the conveyor belt and the traction chain. This is very significant in underground conditions, since it permits relatively easy accommodation to the face requirements. Moreover the device of the invention is very simple in design compared with the known telescopic tensioning stations.

The basis of the invention and two embodiments of conveyor belt storage station will now be described, purely by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a cross-section of a conveyor belt closed to form a hose conveyor; Figure 2 is an axial section through the driving roll of the hose conveyor; Figure 3 is a fragmentary side elevation of a hose conveyor in accordance with the invention, in the area of the driving roll, showing a first embodiment of conveyor belt storage station; Figure 4 is a fragmentary side elevation in the area of the end of the guide rail in a second embodiment of conveyor belt storage station; and Figure 5 is a section taken on the line A-B of Fig. 4.

The hose conveyor, parts of which are shown in the drawing, ia an endless hose conveyor traversing a forward run, a return run, a driving roll, and a reversal station (not shown). The hose conveyor is adapted more particularly for use as a face conveyor in un derground mine workings, and the driving roll is adapted as an unloading station. Figs. 1 and 2 show the basic design of the hose conveyor. It has a conveyor belt 1 which can close to form a conveyor hose, trolleys 2 disposed on its two long edges and guide rails 3, 3a along which the trolleys run. The conveyor belt 1 carries the material 4 to be transported. A traction chain 5 attached to the base or keel of the conveyor belt when it is closed as a hose transmits the traction forces to the conveyor belt 1 and the belt transmits them to the trolleys 2.The driving system comprises a driving roll 6, optionally backed up by additional intermediate driving rolls in the return run 7, though these are not shown.

The driving roll 6 has a central recess 8 for the traction chain 5, where it takes the form of a star wheel 9, having pointed teeth. At the end of the forward run 10 the guide rails 3 diverge in the vicinity of the driving roll 6 so as to open the conveyor hose out into a flat belt configuration which lies against the driving roll as it advances from the forward run- 10 into the return run 7. In the return run, the guide rails 3 do not converge, and the traction chain is disposed above the conveyor belt. (However, it is within the scope of the invention to provide a turnover station in the return run, so that the conveyor belt can be used to transport material along the return run, in which the guide rails 3 do converge).

The trolleys 2 run in guide rails 3, 3a throughout their entire paths. The guide rails 3 are of the hollow box type, with lateral box cheeks 11 and a box floor 12 having a slot 13 for connectors 14 on the conveyor belt 1. In the vicinity of the drawing roll 6, and where the conveyor hose is opened out into a flat belt, the guide rails 3 diverge and twist, thus providing a continuous transition from the normal close setting to a belt-flattening spacing B with their slots 13 facing towards each other.

The hose conveyor has a conveyor belt storage station 15 with a storage length L (Fig.

3) disposed in the return run 7, following on from the driving roll 6 (or it could be after an intermediate driving roll) in the direction z of conveyor belt advance. It has portions of guide rails 3a disposed at the belt-flattening spacing B, between which the conveyor belt 1 is festooned in the direction of advance. The constructional requirements can be met in various ways. Fig. 3 shows a first embodiment in which the portions of the guide rails 3a in the conveyor belt storage station 15 slope downwards in the direction z of conveyor belt advance, at an angle a sufficient to overcome the roller resistance in the trolleys 2. The trolleys 2 spontaneously run down the sloping guide rails 3a under their own weight, at a speed exceeding that at which the conveyor belt is pair off the driving rolls. At the end P of the guide rails 3a in the conveyor belt storage station 15, the descending trolleys 2 are halted, and run together with a shortened trolley spacing a. Since the spacing a between the trolleys 2 running in the guide rails 3a is shortened, the conveyor belt 1 folds up into festoons 16. The guidance of the trolleys 2 in the portions of the guide rails 3a in the conveyor belt storage station 15 prevents the traction chain 5, which is attached at intervals to the conveyor belt 1, from twisting, slipping or disengaging.

The embodiment of the conveyor belt sto rage station shown in Fig. 3 is outstandingly simple in design. In principle, there is no need for mechanical restraining means at the exit from the conveyor belt storage station. Adequate restraint is usually attained if the guide rails 3 leading out of the conveyor belt storage station 15 are horizontal (as shown) or slope upwards.

However, it is within the scope of the invention to provide a mechanical braking attachment at the exit from the conveyor belt storage station. This provision is useful when long surplus lengths of conveyor belting must be stored as festoons and/or the stored surplus length is to be variable over a wide range.

Figs. 4 and 5 show another embodiment of the invention in which a trolley driving attachment 17 is provided on the portions of guide rails 3a in the conveyor belt storage station 15, so that the trolleys are impelled under an adjustable forward pushing force. This provision is sensible when an adequate slope cannot be accommodated. In this embodiment the trolley driving attachment comprises an endless-loop transporter 18 having coupling members 19 for the trolleys 2. The coupling members 19 are elastic pusher pins which yield against an adequate halting force and engage in a suitable recess 20 on each trolley.

Friction members are equally feasible, so that the trolleys are impelled by friction forces. The trolley driving attachment 17 urges the trolleys 2 against a braking attachment 21 at the end P of the portions of guide rails 3a, i.e., at the exit from the conveyor belt storage station 15. The braking force applied by brake cheeks 22 of the attachment 21 is adjustable, as indicated by the use of a spring 23. The braking force can be matched to the tension in the traction chain 4 in the return run 7, or vice versa the chain tension in the return run 7 can be adjusted through the braking attachment 21.

Compared with the known telescopic tensioning devices, the conveyor belt storage station of the invention can accommodate a much longer surplus length of conveyor belting. It is within the scope of the invention to accumulate a multiplicity of festoons 16 in the conveyor be!t storage station. Its storage capacity equals the number of festoons 16 multiplied by the difference between the chain length b between successive trolleys 2 and the trolley spacing a when a festoon is formed. The hose conveyor of the invention is capable of compensating both for load-dependent length variations and for variations associated with chain wear.

Claims

1. An endless hose conveyor traversing a forward run, a return run, a driving roll, and a reversal station, and having a conveyor belt which can close to form a conveyor hose, trolleys disposed on the two long edges of the conveyor belt and running along guide rails, and a traction chain attached to the base or keel of the conveyor belt when it is closed to form a hose, in which the guide rails diverge at least in the vicinity of the driving roll disposed at the end of the forward run, so as to open the conveyor hose out into a flat belt configuration which lies against the driving roll and advances along with the traction chain also lying on the driving roll from the forward run into the return run, together with a conveyor belt storage station having portions of guide rails disposed at the spacing forming a flat belt and between which the conveyor belt is festooned in the advance direction, the conveyor belt storage station being disposed in the return run and following on from the driving roll or an intermediate driving roll in the advance direction of the conveyor belt.

2. A hose conveyor as in Claim 1, wherein the portions of guide rails in the conveyor belt storage station slope downwards in the advance direction of the conveyor belt, at an angle sufficient to overcome the trolley roller resistance.

3. A hose conveyor as in Claim 1, wherein a trolley driving attachment is provided on the portions of the guide rails in the conveyor belt storage station, so that the trolleys are impelled under an adjustable forward pushing force.

4. A hose conveyor as in Claim 3, wherein the trolley driving attachment comprises an endless-loop transporter having coupling members for the trolleys.

5. A hose conveyor as in any one of Claims 1, 3 or 4, wherein the portions of guide rails in the conveyor belt storage station having a braking attachment disposed at the end of those guide rail portions and applying an adjustable braking force which can be matched to the tension in the traction chain in the return run.

6. A hose conveyor as in any one of Claims 1 to 5, wherein the traction chain is passed round a star wheel with pointed teeth incorporated in the driving roll.

7. An endless hose conveyor substantially as hereinbefore described, particularly with reference to Fig. 3 of the accompanying drawings.

8. An endless hose conveyor substantially as hereinbefore described, particularly with reference to Figs. 4 and 5 of the accompanying drawings.