GB2065064A - Air duct storage means - Google Patents

Abstract

A storage means 6 for concertinaable air duct sections 60 comprises a storage tube 1 on which an air duct section 60 in concertinaed form can be mounted, a tapering tube section 3, which is attached by its end of smaller cross-section to an end of the storage tube 1 and over which the air duct section 60 can be slipped and from which it can be removed after being coupled to the end of an air duct system 63, and a mobile draw gear 7 to which the storage tube 1 is attached. One end of an air duct guide sleeve 31 is attached to the end of larger cross-section of the tube section 3, the wall of the sleeve 31 having slits 33 distributed around its circumference for receiving prongs 34 of rakes 35 which are movable radially and axially with respect to the sleeve 31 for the purpose of feeding the duct section 60 along the sleeve 31 and tube section 3 onto the storage tube 1. Piston mechanisms 38 and 42 for moving the rakes 35 are mounted on a shaft 28 mounted within, and disposed substantially in the axial direction of, the storage means 6. The shaft 28 is attached to the draw gear 7 by an arm 24 disposed at or adjacent to the end of the storage tube 1 lying remote from the tube section 3. <IMAGE>

Description

SPECIFICATION Air duct storage means This invention relates to an air duct storage means of the kind comprising a storage tube, on which can be mounted an air duct section which can be concertinaed to form radial folds in its wall, a tapering tube section, which is attached by its end of smaller cross-section to an end of the storage tube and over which said air duct section can be slipped and from which it can be removed after being coupled to the end of an air duct system, and mobile draw gear to which the storage tube is attached.

Air duct storage means are used during the continuous follow-up of the end of an air duct system which blows out or sucks in air depending on the method of operation of the air duct. Such air duct systems are employed, for example, behind heading machines used in mining or tunnel constructions, where a predetermined spacing between the end of the air duct and the heading face is maintained for, interalia, maintaining a stable atmosphere. As the manipulation of the air duct system with fitting pieces can be avoided in this way, storage-type air ducts also achieve a relatively high degree of mechanisation. Concertina-type air ducting having spiral reinforcement can be folded relatively easily if it is collapsed in the axial direction. However, air ducting of this type is relatively costly.Therefore, when spiral-type ducting is used as an air duct storage means, the latter cannot generally be left in the air duct system, but must be replaced by concertinatype air ducting without a spiralling wall after removal from the storage means. However, this air ducting which has no spiral reinforcement can only be slipped on tubes, the cross-section of which is slightly smaller than the maximum cross-section of the concertina-type air duct removed from the storage means, butwhich maintains the reduced crosssection of the air duct system in the area of the stored air duct.

An air duct storage means of the last-mentioned kind is known from Swiss Patent Specification 525,380. The storage tube can be connected by its end to a diffuser or to a ventilating fan, which is connected to the draw gear, and the tapering tube section is designed so that it combines with the wall of the air duct to seal the storage tube on the outside, even when the stored concertina-type air duct section is removed from the storage tube. With the aid of the ventilating fan or diffuser travelling on the gallery floor, this operation of removing the concertina-type air duct section is performed as the heading work progresses.

The tapering tube section must be removed to provide the storage tube with a concertina-type air duct section. The air duct section must be slipped over the storage tube in situ, even if it is not desired to remove the storage tube during each storing operation. It is found in practice that slipping a concertina-type air duct section onto the storage tube is such a time-consuming operation, even when several workers are used, that virtually no success can be achieved in terms of mechanisation.

Moreover, it is a disadvantage that the operation of the air duct system must be interrupted whenever a new concertina-type air duct section has to be slipped over the storage tube. As a rule, this means that the gallery head must be cleared until the air duct system is brought into operation again.

In addition, there is a known air duct storage means (Zeitschrift Gluckauf 1973, pages 355,357), consisting of two storage tubes which are provided at their ends with brake bands and attached to a common central tube which serves as a suspension means. With the aid of hoist trolleys which are known in monorail systems used in mining and tunnel construction, the central tube can be suspended from a point in the roof of the heading.The difficulties which arise when storing lengths of concertinatype air ducting which are required for several days are avoided by using exclusively spiral-type air ducting. Eitherthe storage-type air ducting must be removed from the air duct system in accordance with the method described in the introduction and replaced with concertina-type air ducting having no spiral reinforcement, operation of the air duct system having to be stopped in this case, or the storage means are left in the air duct system, butthis is automatically ruled out in the case of prolonged heading work.

in order that concertina-type air ducting without spiral reinforcement may be more easily used as storage-type air ducting, it is known practice (see German Offenlegungsschrift No.2,241,882) to use a storage tube which has at one end a coupling for the concertina-type air duct section and possesses at the other end a suction device, which lies parallel thereto and with which the concertina-type air duct section, closed at its free end, can be drawn into the storage tube so that the air duct is applied as a double layer from within the wall of the storage tube.On account of the difficult operation of drawing the concertina-type air duct section into the storage tube, air duct storage means of this type are relatively prone to trouble and in addition do not permit sufficient lengths of air ducting to be stored in the storage tube without the operation of the air duct system having to be stopped.

Therefore, it has also been proposed that concertina-type air ducting be already folded up during its manufacture in such a way that it can be used as storage-type air ducting. This is achieved, for example, by folding part lengths of the air duct system back over during manufacture and then providing them with longitudinal seams (see German Patent Specification No. 2,421,876). A flat assembly having a barely limited clear inside cross-section is then formed from the concertina-type air duct section, it being possible for the concertina-type air duct section to be drawn out of the said flat assembly to its full length when the assembly has been coupled to the end of the air duct system. However, it has been found that assemblies of this type cannot be coupled when the air duct system is in operation.

Moreover, precautions must be taken to ensure that the part lengths of the concertina-type air duct are not inadvertently disengaged from the assembly, which can easily occur with large diameters and great variations in pressure.

A feature common to all storage-type air ducting is that it only enables the concertina-type air duct to be removed when the air duct system is in operation.

However, as the air duct system, on the other hand, must also be shortened during operation when, for example, the heading machine is moving back and forth, the operation is usually assisted by connecting a a spiral-type air duct to the end of the storage means. However, the amount of movement allowed as a result is very small and is insufficient in many cases. This applies, for example, to gallery heading work in which the end of the air duct system has to be retracted during blasting.

The present invention aims to provide an air duct storage means of the kind referred to which, both when it is separated from the air duct system and when it is fitted therein, can automatically receive and release a concertina-type air duct section without'spiral reinforcement, in which case there is to be provided the possibility of further developing the air duct storage means so that an air duct section can be connected to the air duct system without the latter having to cease operation.

According to the invention, an air duct storage means of the kind referred to, is characterised in that one end of an air duct guide sleeve is attached to the end of larger cross-section of said tube section, the wall of the said guide sleeve having slits distributed around its circumference for receiving prongs of rakes which are movable radially and axially with respect to said guide sleeve, drive means for said rakes being mounted on an elongate member mounted within, and disposed substantially in the axial direction of the storage means, and said elongate member being attached to said draw gear by an arm disposed at or adjacent to the end of the storage tube lying remote from said tube section.

By making the air duct guide sleeve-shaped and connecting it to the tapering tube section, the rakes which serve to move the air duct section, on the one hand, can be incorporated together with their drive means in the air duct system and can therefore also be used to re-install in the air duct system all or part of the air duct section which has been fully or partially removed from the storage means; on the other hand, the wall of the concertina-type air duct section can be moved uniformly along the guide sleeve so that the radial folds, which are inwardly defined by the tapering tube section and by the storage tube, can be formed under the guide sleeve. Therefore, not only can the rakes concertina the air duct section on the guide sleeve, but can also pull the unfolded end of the air duct section.This is based on the possibility of a concertina-type air duct section, which is laid down on the gallery floor or is already installed in the air duct system, being received in the storage means without manipulation. In the air duct system the air duct storage means naturally causes the flow cross-section to be limited. However, said arm not only serves to connect the elongate member to the draw gear, but, optionally, acts also as a stop for the concertina-type air duct section on the storage means. Therefore, the air duct can be concertinaed on the storage tube with an appropriate amount of force. The radial folds can therefore be kept short, which results in correspondingly small radial com ponents of motion of the rake prongs.Since the air duct storage means is now always located on the end of the air duct, but is of short construction for the reasons mentioned, the limitations of the flow cross-section produced by the storage means cause virtually no loss of pressure in the air duct system.

Saicf arm is used, preferably and in accordance with a further feature of the invention, for connection with, a hoist trolley which is knownperse, preferably the overhead monorail system which is known in mining, the arm being connected to one end of a walking beam which extends over and parallel to the elongate member. Walking beams of this type generally consist of a supporting beam, to which the arm is to be connected, and a plurality of hoists which connect the supporting beam to a travel gear beam which holds together two or more trolleys of the overhead monorail system.With the aid of such a device the air duct storage means can be lowered as far as a point above the gallery floor in order to receive an air duct section lying on the said floor and to raise it subsequently to the level of the air duct system so that the end of the stored concertina-type air duct section may be coupled to the air duct system.

The rakes which are used for forming the folds are distributed in the largest number possible around the circumference of the guide sleeve. In accordance with a further feature of the invention, the rakes are arranged so as to be radially movable each with a reciprocatable piston mechanism and so as to be axially movabletogetherwith a common reciprocatable piston mechanism relative to the elongate member.

Since the elongate member, which may be in the form.of a tubular shaft, must extend through the storage tube and the tapering tube section as far as the inside of the guide sleeve, the elongate member may pass right through the guide sleeve and then be used as an end support for a coupling aid. Therefore, in accordance with a further feature of the invention, the free end of the elongate member comprises a retractable device for retaining the tubular end of the air duct system.

This retractable retaining device comprises, preferably and in accordance with a further feature of the invention, a plurality of hoop sections which are located in a substantially radial plane disposed axially beyond that end of the guide sleeve which is remote from said tapering tube section, each of said hoop sections having an outer curvature corresponding to the inner curvature of the end of the air duct system or to that of the end of the air duct section to be coupled, the said hoop sections each being radially movable with the aid of a reciprocatable piston mechanisn fixed to said elongate member. With the aid of the above-mentioned walking beam, the air duct storage means which has been hoisted to the level of the air duct system is moved to such an extent that the retracted hoop sections are located in the air intake or air outlet end of the air duct system.

When the hoop sections are forced out, this results in the air duct storage means being clamped to the air duct system. it has been found that the end of the air duct storage means can then be coupled to the end of the air duct system without the latter having to cease operation.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which Figure la is a partially sectioned side view of one embodiment of an air duct storage means according to the invention, Figure 1b is an end view of the storage means of Figure 1a, and Figures 2-7 show, on a smaller scale than in Figures 1a and 1b, six different stages during the installation of a concertina-type air duct section, using the air duct storage means according to Figures la and 1b.

Figures la and 1b show an air duct storage means generally designated by the numeral 6, which comprises a storage tube 1, on which can be mounted an air duct section which can be concertinaed to form circular radial folds, which is explained in greater detail hereinafter with reference to Figures 2 to 4. A frusto-conical tube section 3 is attached at its end of smaller cross-section to the end 2 of the storage tube 1. The aforementioned air duct section is slipped onto the storage tube 1 via this frusto-conical tube section 3, which is also explained hereinafter with reference to Figures 2 to 4. In addition, the tube section 3 is used to remove an air duct section from the storage means 6 when an end of the air duct section is coupled to an air duct system, which is explained hereinafter with reference to Figures 4to 7.

The air duct storage means 6 co-operates with a draw gear 7 (see Figure 2) which is in the form of a mechanism known per se and is therefore only shown diagrammatically. As shown in Figure 2, the draw gear comprises a trolley provided with runners 8 8 and 9 mounted on the lower flanges of rails 10 of an overhead monorail system. The two runners 8 and 9 are connected to a support 11 in which is mounted hoisting equipment comprising flexible hoisting members 12, 13 which are connected to eyelets 16, 17 on a walking beam 15, see Figure la.

The beam 15 comprises a box-girder element 19, in which a hydraulic pressure generator (not shown) and a control system (not shown) are fitted. The control system is connected to a remote control unit 20 via a cable 21. The end 23 of the walking beam 15 has an arm 24 connected thereto, the free end of this arm comprising an annular flange 25. The annular flange 25 is connected, by a plurality of bolts (not shown) to a flange 26 which is secured around a tubular shaft 28 by gusset plates 27. The geometric axis 29 of the shaft 28 coincides with the geometric axis of the tube 1, and the shaft 28 is rigidly connected to the tube 1 by a plurality of radially disposed arms 22.

One end of an air duct guide sleeve 31, having its axis aligned with the axes of the tubes 1 and 3, is connected to the end 30 of larger cross-section of the tube section 3. The wall 32 of the guide sleeve 31 has a plurality of axially disposed slits 33 distributed around its circumference. A sleeve 39 is slidably mounted on radial guides 47 on the shaft 28 and carries three reciprocatable piston mechanisms 38 projecting radially outwardly from the sleeve 39, the mechanisms 38 being disposed at equi-angular intervals around the shaft 28. Each of the mechanisms 38 includes a cylinder 36 and a piston (not shown) joined to a piston rod 37. Each piston rod 37 carries a rake 35 having a prong 34 at its radially outer end, which can be projected through a respective one of the slits 33 by means of its associated mechanism 38.

The sleeve 39 has a bracket 40 for the flexible connection of the piston rod 41 of a reciprocatable piston mechanism 42, the cylinder 44 of which is pivotally connected to a bracket 45 mounted on the tubular shaft 28. By means of the reciprocatable piston mechanism 42, the sleeve 39 can be moved back and forth along the shaft 28 over distances which are substantially equal to the length of the slits 33. One of the extreme positions of the sleeve 39 is illustrated by chain-dotted lines in Figure 1a, whilst the other extreme position is illustrated by full lines.

A sleeve 49 is attached to the end of the shaft 28 which projects from the end 48 of the guide sleeve 31. The said sleeve 49 serves as a support for the cylinders of three reciprocatable piston mechanisms 50 projecting radially outwardly from the shaft 28 and displaced at equi-angular intervals therearound.

The free ends of the piston rods 51 of the reciprocatable piston mechanisms 50 act on hoop sections 52, each of which is associated with a different one of the reciprocatable piston mechanisms 50. Each hoop section 52 consists of a steel section which is curved to correspond to the inner curvature of end rings of the air duct sections to be coupled together, as will be explained in greater detail hereinafter. The hoop sections 52 are all located symmetrically with respect to a radial plane 53 which is spaced axially of the storage means 6 from a radial plane 54 in which the rakes 35 are disposed.

Downwardly curved members 76 are attached to the upper part 55 of the uppermost hoop section 52 and serve as guides for the wall of a concertina-type air duct section when the latter is installed on the storage means.

Referring now to Figure 2, the rails 10 of the overhead monorail system are mounted in the roof 59 of a gallery 62. The rails 10 are located above an air duct system, which is generally designated by reference numeral 63 and consists of already laid and coupled concertina-type air duct sections 64, 65. End rings 66, which can be held together by a bandshaped clamp 67, are used to couple the air duct sections together. Each air duct section possesses an upper suspension strip 68, to the eyelets of which support means 69 can be connected for suspending the air duct system 63. The installation on the storage means 6 of a concertina-type air duct section, which in Figure 2 is designated by reference numeral 60 and is laid on the floor 61 of the gallery 62, will now be described.

As concertina-type air ducting has no spiral reinforcement, the air duct section 60 can be laid, in the manner shown in Figure 2, with one of its end rings 66 on the floor 61 and then forms a collapsed assembly with radial folds 70. However, the radial folds 70 project inwards to a considerable extent so that the clear internal cross-section is seriously limited. With the piston rods 51 of the reciprocatable piston mechanisms 50 retracted, the upper end ring 66 of the duct section 60 is slipped over the guide sleeve 31 until it is located on the tube section 3. This operation is not illustrated. Then the cycle of movement of the prongs 34, which is indicated by the arrows a to din Figure la, is initiated by way of the control unit 20.In this connection, the prongs 34, in their withdrawn condition relative to the slits 33, are first moved axially in the direction of the arrow a into the position indicated by chain-dotted lines at the left-hand side in Figure 1a by forcing out the piston rod 41 of the reciprocatable piston mechanism 42.

During this movement of the piston rod 41, the wall of the leading portion of the air duct section 60 remains lying on the guide sleeve 31. The piston rods 37 of the reciprocatable piston mechanisms 38 are then forced out so that the prongs 34 execute the movementb, thereby creating a frictional connection and a positive connection between the prongs 34 and the wall of the air duct section 60. This connection is naturally selected in such a way that the wall of the air duct section cannot be damaged. The edges 71,72 of the prongs 34, see Figure fa, are therefore rounded.

The movementb is followed by retraction of the piston rod 41 into the cylinder 44 to perform the movementc. As a result of the connection between the prongs 34 and the wall of the air duct section 60, the part of the latter which lies in front of the prongs 34 slips along the frusto-conical tube section 3 to the storage tube 1. Due to the reduced diameterofthe latter compared with the sleeve 31, radial folds form in the leading portion of the air duct section 60, the radial depth of which, however, is limited by the tube section 3 and the storage tube 1. At the same time, the part of the air duct section 60 which is located behind the prongs 34 is pulled in the direction of the arrow 73, see Figure 3. At the end of movement c, the air duct section 60 occupies the position shown in Figure 3.After the prongs 34 have reached the end of the movementc,the piston rods37 of the reciprocatable piston mechanisms 38 are retracted so that the prongs 34 execute the movement d. As a result, the connection between the prongs 34 and the wall of the air duct section 60 is broken, and the part of the air duct section 60 which is around the sleeve 31 presses against the wall of the latter. As a result, that part of the air duct section 60 which is already lying on the storage means 6 cannot move back because the folds on the storage tube 1 and the tube section 3 exert a relatively high resistance which holds the said part of the air duct firmly.

At this point it should be noted that, through cor responding actuation of the reciprocatable piston mechanisms 38 and 42, the control unit 20 enables the prongs 34 to be moved also in the opposite direction to that of the arrows a to d. As a result, the air duct section 60 can, if necessary, be removed from the storage means.

The series of movements a to d is repeated until the entire length of the air duct section 60, in concertinaed form with inwardly defined radial folds, lies on the storngetube 1 and on the adjacent tube section 3. The storage means 6 is then raised by actuating the hoist equipment forthe walking beam 15, see Figure 4, until the geometric axis 29 of the storage means 6 is substantially aligned with the geometric axis 74 of the air duct system 63. With the aid of the draw gear 7, assisted if necessary by manual operation, the storage means 6 can then be moved to the left to the position shown in Figure 5 until the plane 53 (see Figure 1a) of the storage means is situated behind the end ring 66 of the last air duct section 65 to be fitted to the duct system 63.By forcing out the piston rods 51 of the mechanisms 50, the hoop sections 52 are applied against the inside of the ring 66 of the air duct section 65. As a result, the air duct storage means 6 is secured, without interruption of air flow from the duct system 63, which air flow passes through the interior of the sleeve 31, tube section 3 and tube 1. The end ring of the stored air duct section 60 which is to be associated with the end ring 66 of the air duct section 65 can then be drawn man uallyoverthe sleeve 31 to such an extent that the coupling band 67 can be secured in position to join the air duct sections 60 and 65.During this operation, the major part of the air current through the duct system 63 continues to flow out of the free end of the storage tube 1, and a minor part of the air current flows between the folded wall of the air duct section 60 and the sleeve 31. However, despite the flow resistance to this minor part of the air current, the drop in pressure in the air duct system 63 is virtually negligible.

After retraction of the pistons 51, the storage means 6 can follow the direction indicated by the arrow 75 in Figure 6 as the heading work in the gallery 62 progresses. During this movement of the storage means 6 the wall of the stored air duct section 60 is drawn over the frusto-conical tube section 3 and overthe guide sleeve31, and as a result the folds in the duct section 60 are loosened again. At the same time, the rails 10 of the overhead monorail system can be released and suspension means 69 for the air duct section 60 can be attached to corresponding eyelets in the suspension strip 68.

Finally, the end 77 of the air duct section 60 passes offthe guide sleeve 31, see Figure 7. The storage means 6 can then be lowered once more to the position shown in Figure 2.

However, it should be noted that in the stages shown in Figures 5 and 6 actuation of the prongs 34 can cause the air outlet end of the air duct system 63 to be also laid back, if necessary, by re-installing a corresponding front partial length of the air duct section 60 in the storage means. This is important if, for example, damage to the air duct caused by flying pieces of mine debris during blasting in the gallery heading is to be prevented.

Claims (10)

1. An air duct storage means comprising a stor age tube, on which can be mounted an air duct section which can be concertinaed to form radial folds in its wall, a tapering tube section, which is attached by its end of smaller cross-section to an end of the storage tube and over which said air duct section can be slipped and from which it can be removed after being coupled to the end of an air duct system, and a mobile draw gearto which the storage tube is attached, characterised in that one end of an air duct guide sleeve is attached to the end of larger crosssection of said tube section, the wall of the said guide sleeve having slits distributed around its circumference for receiving prongs of rakes which are movable radially and axially with respect to said guide sleeve, drive means for moving said rakes being mounted on an elongate member mounted within, and disposed substantially in the axial direction of the storage means, and said elongate member being attached to said draw gear by an arm disposed at or adjacent to the end of the storage tube lying remote from said tube section.

2. An air duct storage means according to claim 1, in which said draw gear comprises a hoist trolley having a walking beam disposed above and substantially parallel to the said elongate member, said arm being connected at one end to said elongate member and at its other end to said walking beam.

3. An air duct storage means according to claim 1 or2, in which said rakes are movable radially by means of reciprocatable piston mechanisms which are fixed to a sleeve which is axially movable relative to said elongate member by means of a further reciprocatable piston mechanism.

4. An air duct storage means according to any of claims 1 to 3, in which, at or adjacent to the end of said guide sleeve lying remote from said tube section, said elongate member supports a retractable device for retaining said end of the air duct system.

5. An air duct storage means according to claim 4, in which said retractable retaining device comprises a plurality of hoop sections which are located in a substantially radial plane disposed axially beyond said end of the guide sleeve, each of said hoop sections having an outer curvature corresponding to the inner curvature of said end of the air duct system orto that of the end of the air duct section to be coupled, the said hoop sections each being radially movable with the aid of a reciprocatable piston mechanism fixed to said elongate member.

6. An air duct storage means according to any one of claims 1 to 5, comprising at least one downwardly curved member fixed relative to said guide sleeve for supporting the wall of the air duct section when the latter is fitted on the storage means.

7. An air duct storage means according to any of the preceding claims, in which said tapering tube section is of frusto-conical shape.

8. An air duct storage means according to any of the preceding claims, in which said elongate member is a tubular shaft.

9. An air duct storage means according to any of the preceding claims, in which said arm is radially disposed with respect to said storage tube.

10. An air duct storage means constructed and arranged substantially as herein described with reference to, and as illustrated in, Figures 1a to 7 of the accompanying drawings.