EP0180587A1

EP0180587A1 - Means for extraction installations

Info

Publication number: EP0180587A1
Application number: EP19840903096
Authority: EP
Inventors: Bo Kjelltoft
Original assignee: ANESTECO HAB
Current assignee: ANESTECO HAB
Priority date: 1983-08-10
Filing date: 1984-08-09
Publication date: 1986-05-14
Also published as: SE8304343L; WO1985000764A1; SE8304343D0; JPS60501966A

Abstract

Mécanisme pour des installations d'extraction afin de retirer de l'air par une buse (22). Ce mécanisme possède un premier tuyau (3) pratiquement horizontal, dont une extrémité est raccordée au conduit d'aération (1), qui supporte le mécanisme par une connexion pivotante dotée d'un axe de rotation vertical, lui permettant de pivoter dans un plan horizontal tout en étant incapable de pivoter dans d'autres directions, et dont l'autre extrémité extérieure possède une connexion pivotante (25) dotée d'un axe principal pratiquement horizontal perpendiculaire à l'axe longitudinal du premier tuyau; le dispositif comporte un second tuyau formé d'un certain nombre de sections de tuyau disposées télescopiquement (14, 18) et soutenues par la connexion pivotante (25), dont l'axe est pratiquement perpendiculaire à l'axe longitudinal du tuyau et soutient par son extrémité extérieure la buse (22). Le mécanisme peut être réglé dans des positions effectives dans un sens dirigé vers le bas, ce qui est prévu d'un côté par le pivotement du premier tuyau grâce à la connexion pivotante (34), lorsque l'extrémité portant la connexion pivotante (25) pivote le long d'un arc circulaire et d'un autre côté par le pivotement dans un plan vertical du second tuyau (11, 12) dans un sens radial par rapport à l'axe circulaire grâce à la connexion pivotante (25), et à nouveau en réglant la hauteur de l'extrémité extérieure soutenant la buse (22) grâce au tuyau télescopique (14, 18). Le dispositif peut être placé dans une position prête à l'emploi en faisant pivoter le second tuyau vers le haut jusqu'à ce qu'il soit parallèle au premier tuyau.Mechanism for extraction installations in order to withdraw air by a nozzle (22). This mechanism has a first practically horizontal first pipe (3), one end of which is connected to the ventilation duct (1), which supports the mechanism by a pivoting connection provided with a vertical axis of rotation, allowing it to pivot in a plane horizontal while being unable to pivot in other directions, and the other outer end of which has a pivoting connection (25) having a main axis which is practically horizontal perpendicular to the longitudinal axis of the first pipe; the device comprises a second pipe formed from a number of telescopically arranged pipe sections (14, 18) and supported by the pivoting connection (25), the axis of which is practically perpendicular to the longitudinal axis of the pipe and supports by its outer end the nozzle (22). The mechanism can be adjusted in effective positions in a direction directed downwards, which is provided on one side by the pivoting of the first pipe by means of the pivoting connection (34), when the end carrying the pivoting connection (25 ) pivots along a circular arc and on the other side by the pivoting in a vertical plane of the second pipe (11, 12) in a radial direction relative to the circular axis thanks to the pivoting connection (25), and again by adjusting the height of the outer end supporting the nozzle (22) using the telescopic pipe (14, 18). The device can be placed in a ready-to-use position by rotating the second pipe upwards until it is parallel to the first pipe.

Description

Title of the Invention:

Means for extraction installations

Technical Field:

In operations in which air contaminated by, for example, toxic gases or smoke is encountered, the greatest possible effort is made to collect the contaminated air directly at source by means of a so—called point or local extraction system for the air, which is collected by means of a nozzle at the point where the contamination is being produced. This invention relates to a means which constitutes such a local extraction system. The area of application for which the means has been designed is the extraction of the anaesthetic gas released in the course of surgical operations If it is assumed that the anaesthetic system by means of which the gas is distributed to the patient possesses good sealing and is connected to an extraction line for used gas, then the undesired release of gas will occur at the point at which the equipment is connected to the patient, that is to say at the patient's mouth and nose. Extraction should accordingly take place at this point in order to prevent the spread of the gas released there. It has, in fact, been observed that the risk of damage to the health can arise if the theatre staff are exposed to gas distributed inside the operating theatre.

Description of the Prior Art

Previously disclosed is the arrangement of a local extraction system in operating theatres and in other areas, such as the places where welding is performed. The arrangement in such cases is so executed as to be connected to a fan, usually within a central extraction system, with a pipe terminating in a suction nozzle leading from the point of connection. The pipe is adjustable in such a way that the nozzle can be positioned at the point at which the contamination is produced. It is also desirable, especially in the present context, for the pipe to be capable of being folded away into a storage or ready—for—use position in which it does not constitute an obstruction in those cases in which the local extraction system is not to be used.

Disclosed in DK, B, 143 538 is an extraction system having two pipes so arranged, as to be capable of pivoting about horizontal axes, said pipes being attached one after the other to an extraction shaft enabling the pipes to rotate about a vertical axis. The arrangement comprises a total of three pivotally mounted pipe connections, of which the connection with a horizontal axis arranged closest to the extraction shaft is subjected to high torsional forces. The arrangement does not exhibit any particular storage position. Disclosed in DE, A1, 3 132 361 is an extraction arrangement consisting essentially of a Linked system of several pipes pivotally mounted along vertical axes together with a nozzle— —supporting component which is not only pivotally mounted along vertical axes, but is also pivotally mounted about a horizontal axis and is furthermore arranged in a telescopic fashion. The arrangement is very complex and has an air path curved into a number of wind baffles, which produces high air resistance.

Technical Problem:

Experience has shown that it has been very difficult until now to produce a pipe system which is at the same time adjustable through a wide range of positions and capable of being folded well out of the way and which meets all existing functional requirements, such as complete adjustab lity over a wide range, the ability to be operated without the need for excessive effort and for the actuation of complex operating controls, a small space requirement when folded out of the way, low air resistance and a low noise level if at the same time requirements such as simple, rational manufacture and a reasonable price are to be satisfied.

Solution:

The solution in accordance with the invention is characterized by a means of the aforementioned kind consisting of a first pipe system having an essentially horizontal principal direction, one end of which is connected to the air shaft or similar by means of a swivelling connection with an essentially vertical axis of rotation enabling it to be swivelled in a horizontal plane whilst remaining incapable of being swivelled in other directions, and the other. outer end of which exhibits a swivelling connection having an essentially horizontal principal axis situated on a line which is essentially perpendicular to a line passing through the longitudinal axis of the first pipe system, and a second pipe system formed from a number of pipes arranged telescopically in relation to each other and is isupported by the swivelling connection, the axis of which is essentially perpendicular to the longitudinal axis of the pipe system and supports by its outer end at the other end to the swivelling connection a pipe section which is terminated by a nozzle in such a way that the means can be adjusted in ready—to-use positions in a downward-facing sense, on the one hand by causing said first pipe system to swivel in said horizontal plane by means of the swivelling connection, in which case the end with the swivelling connection is swivelled in a circular arc, and on the other hand by causing the second pipe system to swivel in a vertical plane in a radial sense in relation to said circular arc by means of the swivelling connection, and yet again by adjusting the height of the outer end which supports the nozzle by means of the telescopic pipes, whereby the ready—for—use position can be achieved by causing the second pipe system to swivel upwards with its longitudinal axis essentially parallel with the essentially horizontal longitudinal axis of the first pipe system.

Advantages:

Through the present invention there is proposed a means for providing a local extraction system which satisfies the aforementioned requirements and which is especially suited to the extraction of anaesthetic gas in operating theatres. Through the invention there is achieved an arrangement which is easy to operate and which can be adjusted to all necessary positions within a wide range, but which in spite of this possesses a storage position in which it is folded well out of the way, which exhibits simple flow paths and thus a low noise level and a low flow resistance, and which is simple with regard to its execution and constituent parts, thus enabling a reasonable manufacturing cost to be achieved. Description of the Drawings:

An embodiment of the invention is described below which is illustrated in the accompanying drawings. Figure 1 shows a perspective view of the means; Figure 2 shows a partly sectioned view of the means from above, based on the Section marked II—II in Figure 3; Figure 3 shows a partly sectioned side view of the means; Figure 4 shows a detail of the means in a section along the plane of the paper in Figure 2} and Figure 5 and Figure 6 show other details of the means.

Preferred Embodiments:

The principal component parts of the means and their relative positions may be appreciated from the perspective drawing in Figure 1. The means is connected to an air shaft 1-, which forms part of an extraction installation and inside which low pressure is present during operation. The air shaft 1 is situated well above head height, providing clearance for pedestrians beneath the means when it is folded up into its read^-to—use position, as described below.

The shaft 1 is terminated by a flange 2 , into which there is incorporated a swivelling connection, as described below, for a pipe system 3 - The pipe 3 consists of an elbow 4 with an angle of 90 , the outer end of which is connected to the shaft 1 by means of said swivelling connection. The pipe 3 also exhibits a straight pipe section 8 which is terminated by a short pipe 5 set at right angles to the pipe 4 .

As already mentioned, the shaft 1 extends downwards from the ceiling of the room, and its terminating flange 2 is essentially horizontal, The axis of the aforementioned swivelling connection is vertical, and the right angle of the pipe elbow 4 thus causes the pipe 8 to lie horizontally, and the axis of the end pipe 5 is also horizontal. By causing the swivelling connection to rotate the end pipe 5 can be made to swivel along a circular path which lies in a horizontal plane.

The end pipe 5 exhibits a closed, outer end 6 and an open end 7 , which is connected via a swivelling connection 25 to a

'BUREA OMPI second pipe arrangement 10 consisting of three principal component parts, being an upper pipe 11 , a lower pipe 12 and a terminating pipe 13 . The upper principal pipe in turn consists of a straight pipe 14 and a short pipe 15 set at a right angle in relation to the latter, the one outer end 16 of which is closed and the other end 17 of which is connected to the swivelling connection 25 .

The principal pipe 12 consists of a long, straight pipe 18 supported telescopically in the pipe 14 and capable of sliding against the latter by means of a sleeve 19 which acts as a seal and as a friction connection.

The principal pipe 13 consists in turn of a pipe elbow 20 attached to the outer end of the pipe 18 , this being the opposite end to that with the sleeve 19 , and a flexible hose 21 running from the outer end of the pipe elbow, said hose being terminated by a suction nozzle 22 . The flexible hose 21 is designed to enable the the adjustment of the nozzle 22 to different positions, and it must be sufficiently rigid to ensure that the nozzle is held in the position.to which it has been adjusted. There are in existence previously disclosed hoses which satisfy these functional requirements and which are usually executed in convoluted form in plastic or metal. The pipe elbow 20 is pivotally mounted on the pipe 18 in such a way that the flexible hose 21 and thus the nozzle 22 can be pointed in different directions.

By means of the swivelling connection 25 the pipe arrangement 10 can be adjusted to different positions by causing it to rotate in a vertical plane, the position of which in relation to the shaft 1 is determined by the angle through which the pipe arrangement 3 turns as it describes the aforementioned rotation,. The possible angle of rotation for the pipe arrangement 10 shall be such that the principal pipe 12 can be folded up at least into a position parallel with the pipe 8 , when the means will adopt the aforementioned ready—for—use or storage position. In order that the pipe 12 shall be retained in this position, the pipe 8 is provided with an adjustable locking device^' 23 which is described in greater detail below. Any movement from the ready—to—use position

OMPI < WIPO and downwards and upwards in the other direction is for the purpose of effecting adjustment to other working positions, and the angle shall be so great in relation to the length of the pipe arrangement that the pipe elbow 20 can be adjusted into positions in relation to the other equipment in the room such that the nozzle 22 can be directed by means of the hose 21 into the desired working position where the patient's mouth and nose are situated.

In Figure 2 are shown those arrangements which are situated beneath the flange 2 in a section along the line II—II , as shown in Figure 3, The plane of the section is thus horizontal, and the direction of observation is downwards. As may be appreciated from Figure 2, the pipe 3 is situated in a position with the end pipe 5 in the horizontal plane and is supported inside the latter at all times by the rigid pipe elbow 4 by means of the swivelling connection attached to the flange 2 «. On the other hand the pipes 11, 12 can, as has already been mentioned, be swivelled into dffferent positions in a horizontal axis via the swivelling connection 25 . The pipe arrangement 10 is shown in Figure 2 to have been swivelled upwards into a horizontal position between the pipe 8 and the pipes 11, 12 , that is to say into the ready—for—use or storage position, The pipe 12 then rests against the locking arrangement 23 »

According to Figure 5, which shows a section along^" the line V—V in Figure 2, the locking device 23 consists of a bracket 26 with a hinge 27 at its outer end welded to the horizontal pipe 8 of the pipe arrangement 3 _* A locking plate 28 is pivotally attached to the hinge 27 . The locking plate 28 exhibits an outer end which is executed in the form of a support 29 for the pipe 18 of the principal pipe 12 . As may be appreciated from Figure 5, the principal pipe 12 has been swivelled upwards into a horizontal position in which it is parallel with the pipe 8 , and in which it rests against the support 29 . This in turn is prevented from being swivelled downwards by the locking plate

28 exhibiting a component part 30 corresponding to the support

29 , said component part being situated on the other side of the hinge 27 and, when it is in a position in which it provides support for the locking device, resting against the bracket 26 , To the outer end of the component 30 is attached a drawstring 3 with a handle 32 . Because the component with the support 29 is longer than the component 30 , its weight will endeavour to hold the component 30 up against the bracket 26 even when the pipe 12 is not resting against the support 29 .

When the pipe arrangement 10 is to be 'stowed', the pipes 11, 12 are folded upwards, in so doing raising the end of the locking plate 28 with the support 29 . Once the pipe 12 has moved to a certain extent beyond the horizontal position, the locking plate 28 will swing back, causing the pipe to move past its end, and the component 30 will then rest against the bracket 26 , The pipe 12 can now be folded back and slightly downwards, when it will rest against the support 29 , as shown in Figure 5. By pulling on the drawstring 31 by means of the handle 32 the locking plate 28 can be released by raising the pipe 12 slightly, allowing the support -29 to pass to the upper side of the pipe, when the pipe will have lost its support and can be folded down into the working position.

The means is shown in side view in Figure 3, in which the swivelling connection, here designated 34 , supported by the flange 2 is shown in section. The manner in which the pipe elbow 4 continues upwards with a short, straight part 35 may be appreciated from the Figure. Around the latter is attached by means of screws 36 a flange piece 37 consisting of a cylindrical, tubular part 38 and a flange 39 . The flange 39 is held against the flange 2 by means of a ring 40 , which in turn is attached to the flange 2 by means of screws 41 . The seating thus formed for the flange 39 is made to fit in such a way as to endow it with adequate clearance both axially and radially to be capable of turning relative to the flange 2 . The seating should preferably be provided with a friction—reducing coating enabling it to turn at a resistance so dimensioned that the principal pipe 3 may with certainty be retained in position, yet remain capable of being turned by hand.

The flange 2 is held securely to the air shaft 1 by means

OMP of screws 42 . When the end of the pipe 35 is open, the channel which extends through the pipes of the means as far as the nozzle 22 will be in contact with the inside of the air shaft 1 .

Also illustrated in section in Figure 3 is the sealing sleeve 19 between the principal pipes 11 and 12 * This consists of a collar 44 which is attached to the pipe 18 and which rests against the pipe 14 in a sliding joint. In that part of the collar 44 which rests against the pipe 14 are bored a number of holes, into which are inserted plugs 45 . The plugs 45 are forced inwards against the pipe 14 by means of an elastic ring 46 which is concealed by an outer, cylindrical ring 47 , which is pushed onto the outside of the collar 44 . The collar 44 is thus provided with a seating for the ring 47 and a groove for the ring 46 , and with holes running from the bottom of said groove and extending inwards all the way to the innermost diameter of the sleeve.

In the assembled state illustrated in Figure 3, the plugs 45 are caused to rest against the pipe 14 by the pressure exerted by the ring 46 . The plugs are thus a sliding fit in their holes. A well matched degree of friction against the pipe 14 is achieved in this way, which means that the pipe 18 can be pushed in and out along same without excessively high resistance but at the same time in the presence of sufficient friction to cause the pipe 18 to remain in position irrespective of the extent to which it is subjected to loadings in the form of its own weight and the weight of any connected component parts. In order to prevent the sleeve 19 from being drawn out over the end of the pipe 14 , a line 48 is attached to the swivelling connection 25 which joins together the pipe arrangement 3 and the pipe arrangement 10 , and to a screwed attachment point 49 in the pipe 18 . If the pipes 14 and 18 are pushed together in the manner illustrated in Figure 3, the line 48 will become folded. If the pipes are pulled apart, the line will be extended, and its length is such that the sealing sleeve 19 will remain at an appropriate distance from the end of the pipe 14 . In the upper position the ^' screwed attachment point 49 will act as a stop against the lower end of the pipe 14 .

OMPI Also apparent from Figure 3 are the other component parts of the means described here. The Figure shows two working positions, one drawn in unbroken lines and the other in dotted and dashed lines. It can be seen that the nozzle 22 may be turned to face both in an upward and in a downward direction by the appropriate bending of the hose 21 .

The swivelling connection 25 may be seen in Figure 4. In this Figure are shown the pipe arrangements 3 and 10 and the end pipes 5 and 15 , Both pipes have their respective ends 7, 17 fully open. Each of the ends is provided with its own collar 52 and 53 , each with its own seating for the respective pipe end. The pipe ends are well secured to the collars, preferably as a push—fit. The collar 52 is executed with an outer ring 54 which forms a bearing seat 55 for the collar 53 , The seating provides both radial and axial support, and for the purpose of absorbing any axial forces a ring 56 is inset in the seating 55 . The ring is made of a material which is capable, under the appropriate pressure, of providing suitable friction in the bearing such that the pipes 5 and 15 may with certainty be turned in relation to each other, yet remain held in the adjusted position when subject only to the loading imposed by their own weight.

The outer ends 6 and 16 of the pipes 5 and 15 are provided ^•with end walls 58 and 59 . The end wall 58 is provided with a depression 60 with a hole for a tie rod 61 which is attached in a pre— etermined position in the end wall 58 by means of a domed nut 62 and an inner, locking nut 63 . The tie rod 61 extends out through the other end wall 59 , which also exhibits a depression 64 . The depression 64 is so arranged as to provide a seating for an axial ball bearing 65 . The tie rod 61 is supported in the ball bearing 65 in such a way as to be capable of being displaced and extends beyond the end wall by one of its ends provided with a thread 66 . There rests against the ball bearing via an interjacent washer 69 a nut 24 screwed onto the thread 66 , The washer 69 projects beyond the nut by a considerable amount. Onto the thread 66 is also screwed a nut 67 arranged in a manner in which it is unable to rotate in a

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handwheel 68 which bears against the inner race of the ball bearing 65 via the projecting periphery of the washer 69 , Also shown in the Figure is the manner in which the tie rod 61 is used to retain an attachment point 70 for the line 48 .

By causing the nut 67 to turn by means of the handwheel 68 it is possible to apply different degrees of tension to the tie rod 61 , thereby imposing different axial loadings on the bearing seat 55 and thus different pressures against the friction ring 56 , In this way the handwheel 68 will apply pressure against the ball bearing via the washer 69 . However, the arrangement is held together not only by the handwheel, but also by the nut 24 , so that the force holding together the arrangement would not be lost if some person were to unscrew the handwheel by mistake. The nut 24 is tightened to a certain basic torque loading which in any case will overcome the weight of the pipe arrangement 10 in such a way that it will not drop down in the event of the handwheel being released. At the other point of assembly for the components connected to the pipes 5 and 15 , that is to say at the end jyall 59 , a practically unchanged level of friction is maintained by the absorption of the force by the ball bearing 65 .

The nozzle 22 is shown in Figure 6. Its purpose is to suck in the air extracted via the pipework within a limited area, which is determined by the outer ring 71 of the nozzle. In order to utilize the suction effect to the greatest possible extent, the flow of the air through the nozzle must be disturbed to the least possible extent. Some form of inlet guard is required, however, in order to prevent loose objects from being sucked in unitentionally via the nozzle. In Figure 6 is shown an inlet guard consisting of four plates of a certain width bent into the form of a quarter circle terminated by straight ends. The straight ends extend forwards as far as the ring 71 and are inserted in grooves in same in such a way as to be attached to it. Through the centre there also extends a straight plate 75 which divides up the central part into two smaller parts. The five plates 72 in this way form not only four approximately semi—circular suction areas 73 along the periphery of the nozzle, but also two central

ISUR^EA

OMPI are,as 74 . This arrangement has been found to provide adequate inlet guarding for the intended use thanks to the relatively limited areas 73 and 74, In spite of this the plates 72 present very low flow resistance and to all intents and purposes do not in any way contribute to wind noise or produce turbulence which can disturb the inlet flow. It has been demonstrated by practical experiments that the means specified here produces lower flow resistance than an equivalent round opening without any inserts, at the same time as the incoming flow of air is very much less likely to break up in the turbulence in the event of disturbance. This arrangement is thus highly advantageous and very much more advantageous than, for example, a mesh, which is often used in similar applications.

Low pressure will thus be present inside the air shaft 1 during operation; it is usual for this to be connected to a central extraction system. Since a system of this kind usually operates continuously, it is preferable in this case to arrange a shut—off valve in the air shaft. The air shaft can also be connected to a fan, which may be arranged separately for one or more local extraction means. The extracted air will flow from the nozzle 22 and in past its plates 72 via the pipe 13., via the telescopically arranged pipes 12 and 11 , from the end pipe 15 to the end pipe 5 via the swivelling connection 25 and through the principal pipe 3 and into the air shaft 1 via the arrangement in the swivelling connection 34 . When the nozzle is directed towards the intended inlet point for the air, the principal pipe 3 is caused to turn in the swivelling connection 34 in such a way that the swivelling connection 25 will be situated approximately above the inlet point. Further adjustment can. then be effected by causing the pipe arrangement 10 to swivel in the swivelling connection 25 . The final adjustment to the desired position, with regard both to the positioning and to the direction of the front area of the nozzle 22 in relation to the inlet point, may then be performed by means of the flexible hose 21 associated with the principal pipe 13 . In relation to the circle of swivel within which the swivelling connection 25 can be swivelled, rotation of the swivelling connection 34 will permit adjustment to be made along the periphery, whereas the swivelling connection 25 will permit adjustment to be made in a radial sense. The basic adjustment for height is achieved by causing the principal pipes 11 and 12 to be displaced in relation to each other, in conjunction with which adjustment can be made to the change in the height of the lower part which will occur at different angles of rotation of the principal pipes 11, 12 . The principal pipe 13 is capable of adjustment in all directions.

Wheft the means is not being used, it can be 'stowed' in the aforementioned manner by folding up the pipe arrangement 10 and making the locking device 23 secure. Because the folding part consists of a single pipe arrangement capable of being folded into a fixed, horizontal pipe, the pipe arrangement can be folded well out of the way and can be folded out simply and positively. The principal pipe 13 is so executed and secured that it will not be situated so far down as to be in the way. The folding function can also be used in emergency situations. The situation may, of course, arise in an operating theatre in which the patient rtwst be given emergency treatment, in the course of which the local extraction system could well be in the way. In the case of the means in accordance with the invention, however, the arrangement can be moved out of the way rapidly and simply using only one hand. This can also be advantageous in the case of a welding extraction system, for instance in the event of fire breaking out, which can be aggravated by air being sucked past the point of the fire, for the fighting of which space may be needed. When folding down the means into the working position, the lock may be released, as has already been mentioned, by pulling on the handle 32..

A highly useful arrangement is provided by the invention, which at the same time is of simple construction and is easily operated. The flow resistance and noise generation are low thanks to the simple pipework and the design of the nozzle. The number of swivelling connections is two only, which contributes to excellent durability and low servicing needs. In spite of the fact that the means is highly adjustable in order to achieve the most_, beneficial working position, it can also be folded up out of„ the way without the need for any dismantling and without causing obstruction in its folded-up position to the activities being pursued in the room in which it is installed. In all these respects, the means differs in a beneficial sense from previously disclosed means.

The especially advantageous embodiment specified here is illustrated in the drawings. This embodiment exhibits an excellent operating function and is at the same time of simple execution. In certain applications, however, for example if it is wished to achieve a very wide range of adjustment, it may be executed differently within the context of the following Patent Claims. Accordingly, the horizontal pipe arrangement 3 may be executed with several swivelling connections and interjacent pipe connections, or it may also be made telescopic, enabling the radius of swivelling of its outer end to be changed and enabling a larger surface to be covered. The means in accordance with the invention is not restricted to the detail embodiments indicated.. Thus the expressions swivelling connections or rotating connections are not intended to denote simply connections of the swivelling type, but also connections incorporating hoses or other flexible elements.

OMPI

Claims

Patent Claims:

1. A means for extraction installations for the removal of air which via a nozzle (22) is collected at a generation point for impurities and which is connected to a space inside an air shaft (1) or similar, inside which low pressure is generated, said means exhibiting a pipe (3, 10) which is connected to said space and the outer end of which is terminated by the nozzle (22), said pipe consisting of rigid pipe sections (8, 14, 18) and connections (25, 34) enabling the pipe sections to swivel in relation to each other and to the air shaft or similar so that the nozzle can be directed towards said generation point and so that the means can be moved into a ready—for—use position, c h a r a c t e r i z e d by a first pipe arrangement (3) running in an essentially horizontal sense, one end of which is connected to the air shaft (1) or similar via a swivelling connection (34) having an essentially vertical axis or axes of rotation enabling it to be swivelled in a horizontal plane_, whilst remaining incapable of being swivelled in other directions, and the other, outer end of which exhibits a swivelling connection (25) having an essentially horizontal principal axis situated on a line which is essentially perpendicular to a line passing through the longitudinal axis of the first pipe arrangement, and a second pipe arrangement (11, 12) formed from a number of pipes (14, 18) arranged telescopically in relation to each other and supported by the swivelling connection (25), the axis of which is essentially perpendicular to the longitudinal axis of the pipe arrangement and supports by its outer end at the other end to the swivelling connection (25) a pipe section (13) which is terminated by the nozzle (22), in such a way that the means can be adjusted in ready—to-use positions in a downward—facing sense, on the one hand by causing said first pipe arrangement to swivel in said horizontal plane by means of the swivelling connection (34), in which case the end with the swivelling connection (25? is swivelled in a circular arc, and on the other hand by causing the second pipe arrangement (11, 12) to swivel in a vertical plane in a radial sense in relation to said circular arc by means of the swivelling connection (25), and yet again by adjusting the height of the outer end which supports the -' nozzle (22) by means of the telescopic pipes (14, 18), whereby the ready—foi—use position can be achieved by causing the second pipe arrangement to swivel upwards with its longitudinal axis essentially parallel with the essentially horizontal longitudinal axis of the first pipe arrangement.

2. Means in accordance with Patent Claim 1, c h a r a c t e r ¬ i z e d in that the first pipe arrangement (3) supports a releasable locking device (23) by means of which the second pipe arrangement (11, 12) can be secured in the aforementioned ready— o-use position.

3. Means in accordance with Patent Claims 1 or 2, c a r ¬ a c t e r i z e d in that the pipe section (13) consists for the purpose of supporting the nozzle (22) of a flexible hose (21) enabling the nozzle (22) to be adjusted in different directions and positions in relation to the second pipe arrangement (14, 18).

4. Means in accordance with latent Claim 3, c h a r a c t e r ¬ z e d in that the first pipe arrangement (3) comprises a pipe bend (4) with an angle of essentially 90 which joins the swivelling connection and an essentially straight pipe (8.) which extends in the horizontal principal axis and which is terminated by an end pipe (5) set at an angle which forms part of the swivelling connection (25), and in that the second pipe arrangement (11, 12) comprises a straight pipe (14), the end of which is terminated by an end pipe (15) transverse to the straight pipe formin part of the swivelling connection (25) and a second straight pipe (18), said straight pipes (14, 18) constituting the pipes which are arranged telescopically inside one another, with the two end pipes (5, 15) being pivotally connected end to end and closed at their outer ends (6, 16) which face away from each other.

5. Means in accordance with Patent Claim 4, c h a r a c t e r ¬ z e d in that the second, outer pipe (18) in the second pipe arrangement (11, 12) is closed at its outer end by means of a pipe elbow ⁽20) to which is attached the flexible hose (21) which supports the nozzle (22), with said second pipe (18) and the pipe elbow (20) being pivotally connected.

OMPI

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6. Means in accordance with any of the foregoing Patent Claims, c h a r a c t e r i z e d in that the nozzle (22), which is of essentially circular section, exhibits in its function as an inlet guard preferably four pieces of material (72) bent into the approximate form of a quarter circle, the ends of which are attached to the periphery (71) of the nozzle, said pieces of material exhibiting a certain width, so that in addition to dividing up the cross—section of the nozzle into several areas (73, 74) a means is also provided for controlling the incoming air flow.

7. Means in accordance with Patent Claim 6, c h a r a c t e r ¬ i z e d in that centrally positioned in the nozzle (22). is at least one additional, straight piece of material (75.) which divides the central area into four further subordinate areas (74).

OMPI