EP0674597A1

EP0674597A1 - Pressure pad, in particular for filling mining cavities

Info

Publication number: EP0674597A1
Application number: EP94900816A
Authority: EP
Inventors: Bernd KRÖPLIN; Torsten Talmann
Original assignee: KROPLIN Bernd
Current assignee: KROPLIN Bernd
Priority date: 1992-11-21
Filing date: 1993-11-17
Publication date: 1995-10-04
Anticipated expiration: 2013-11-17
Also published as: ATE171442T1; CA2149908A1; WO1994012423A1; EP0674597B1; AU5563094A; DE59309016D1; DE4339211A1

Abstract

A pressure pad can be used in a particularly advantageous manner in underground mining with shield-type support for temporarily propping the ground, for aligning and lifting heavy parts and for timbering drifts, tunnels or comparable cavities within rocks. The pressure pad has an at least partially flexible envelope (12) which contains a plurality of chambers (22). A fluid may be introduced inside the chambers (22) by an appropriate arrangement in order to support the envelope (12) against pressure strains from outside. In order to simplify production and handling, the chambers are designed as sections of a pressure hose which is preferably folded up inside the envelope in a special manner. This pressure pad may be inflated in a very short time, preferably with compressed air, in order to temporarily support excavations, for example.

Description

Pressure kits, especially for filling cavities in mining

The invention relates to a pressure pad with an at least partially flexible sleeve that is inflatable by feeding a medium into the interior of the sleeve.

In underground mining, especially in hard coal mining, the working area in the longwall is secured with the help of hydraulically operated protective devices, so-called shields. Another function of these shields is to prevent rock from re-breaking by maintaining a certain support pressure on the slope. When mining coal seams in underground coal mining, so-called outbreaks occur with greater or lesser regularity, depending on the geological conditions, that is to say cavities that arise during tunneling if the coal layer breaks away when the coal layer is removed. These cavities have to be filled before advancing further in order to establish contact between the shield surfaces and the rock and to support the hanging wall, otherwise the rock will continue to rupture and the excavation will expand far beyond its original extent, which is an intolerable security risk represents and may even make further advancement impossible.

Filling out such outbreaks using the previously known devices and methods requires a longer stay of the workers under the unsecured slope, which leads to frequent and serious, not infrequently fatal accidents due to stone and coal falls during this activity. In addition, there is a high consumption of materials, especially wood and / or other building materials, such as Foam concrete, which are used for filling. After all, the high expenditure of time of up to one week required to carry out the work leads to serious production downtimes.

In order to allow cavities in mining to be filled up quickly, containers or pressure cushions have been developed which are filled from the inside with a multi-component mixture, preferably with a two-component foam, which completely fills the interior of the cushion and ensures stability of the cushion (DE 35 00 041 AI).

It has proven to be disadvantageous here that the cushions can only be used after a sufficient curing time, since otherwise the compressive strength is not sufficient. Furthermore, pressure cushions of this type, in which multi-component mixtures such as two-component foam are used, are very expensive and require large amounts of valuable raw materials. There are also environmental and occupational safety problems that are caused by the outgassing proportion of formaldehyde. The heat generated when the multicomponent mixture hardens is also undesirable, particularly in mining, since it can lead to an uncontrolled heating of the pressure pad, so that such pads cannot be used, especially if there is a risk of explosion due to an unfavorable gas mixture. Finally, the known pressure cushions have the disadvantage that they can only be used once and then, when they are no longer used after a temporary use, can only be removed again with great effort.

The invention has for its object to provide an improved pressure pad which avoids the disadvantages of the prior art and enables the most universal use possible for other tasks. In particular, a high pressure load capacity is to be ensured in order to enable heavy loads to be supported and the largest possible volume to be filled in a simple and quick manner. Furthermore, availability should be as fast as possible and a high security standard should be maintained despite the lowest possible costs.

This object is achieved according to the invention by means of a pressure cushion, with an at least partially flexible envelope, within which a plurality of chambers is provided, with a device for supplying a fluid into the interior of the chambers under pressure to support the envelope against external pressure loads. According to the invention, a plurality of chambers are provided which are enclosed by a common shell. Since the pressure according to the invention is therefore not absorbed by a single chamber, but any number of individual chambers can be provided, depending on the size of the casing, it is possible to fill relatively large volumes without causing a high load on the chambers would. Furthermore, it is possible to make the individual chambers pressure-tight independently of one another, so that in the event that individual chambers should be damaged, sufficient stability of the pressure pads is still guaranteed. As a result of the considerably smaller volume of the individual chambers, when filled with a fluid under pressure, these can absorb a considerably higher pressure than would be possible with a pressure cushion with a single pressure chamber.

Another advantage of the embodiment according to the invention is that the casing can be better matched to the mechanical stress from the outside, since it does not have to be made gastight. According to the invention, a decoupling of the functions of the shell and the chambers is achieved. This makes it possible to use a mechanically particularly resistant material, that is to say in particular tear-resistant and cut-resistant material, as the shell material, while the wall material of the chambers can be specifically matched to high pressure resistance and gas tightness. Only through this decoupling according to the invention is a pressure cushion made possible which ensures an optimal combination of the above-mentioned functions of the shell and chambers.

A pressure pad according to the invention has an extraordinarily high resilience and resistance to mechanical damage, with other advantages at the same time a low transport volume and weight as well as quick and easy handling are given. As a result of the construction with a plurality of chambers, there is also effective protection against explosive escaping compressed air in larger quantities in the event of damage or overload and against a sudden failure of the entire supporting force.

In a preferred development of the invention, at least some of the chambers are formed by individual sections of a pressure hose which are separate from one another. This measure has the advantage that the chambers can be implemented in a particularly simple manner. For the purpose of particularly simple manufacture and handling, a single pressure hose can be used within the casing, which is divided into the chambers.

Although in principle the chambers can be formed, for example, by tying the pressure hose, the pressure hose in a particularly preferred embodiment of the invention is divided into the chambers by folding. A pressure hose is therefore introduced into the casing and is folded up in a suitable manner.

This can happen, for example, in that the pressure hose is folded alternately from left to right and back again, so that the shape of a folded heating coil results. The length of the individual sections expediently corresponds to the length of the casing when inflated. After the ends of the pressure hose have been folded and tied, the pressure hose is preferably put together in a certain way, for example with five sections next to one another and five sections one above the other and fixed in this form, for example with sealing tape, before it is inserted into the outer casing. Water, which is usually available in sufficient quantities in mining, can be used as the fluid that is introduced under pressure. Particular advantages result if a gas, in particular compressed air, is used as the fluid. This results in a greatly simplified handling and a particularly low weight of the pressure pad when inflated. A pressure pad with a length of a few meters and a diameter of up to one meter has a weight of around 10 to 25 kg, depending on the design of the cover, and can be folded up in a narrow space when not in use. The necessary pressure can be generated on site by a compressor or by another compressed air connection or by means of a gas bottle.

In an advantageous development of the invention, a control device for pressure regulation of the fluid is provided.

This makes it possible to change the internal pressure of the chambers and thus to adapt the chamber volume depending on the external load on the casing. Thus, the volume of the casing can be adapted within certain limits, for example to the volume of an eruption. Furthermore, the pressure cushion can be used as a lifting device for lifting heavy parts and also for vertical alignment of the parts if the pressure is changed.

A pressure relief valve is expediently provided in this case in order to avoid exceeding the maximum permissible pressure of the chambers in any case.

In principle, a wide variety of materials are suitable for the manufacture of pressure hoses. For example, metal foils such as aluminum foils or the like come in Question. However, particularly preferred are high-strength plastic materials which are already commercially available in tubular form.

According to the invention, it is particularly preferred that the pressure hoses consist of polyterephthalic acid esters. This material has a high tensile strength and an almost linear stress-strain curve. In single tubes with a wall thickness of approximately 35 micrometers up to a diameter of approximately 5 cm, this material can absorb an internal pressure of approximately 2 bar with sufficient certainty. If a higher pressure is required, multiple hoses can also be used. A two-layer hose made of polyterephthalic acid ester with a diameter of about 5 cm can be loaded with sufficient security with an internal pressure of about 5 bar.

The use of two-layer pressure hoses, which can be used for large-volume casings with a diameter of approximately 15 to 18 cm and an operating pressure of approximately 0.5 bar, is particularly preferred for underground mining applications.

Depending on the required mechanical robustness of the cover and the resistance of the cover to the penetration of foreign bodies, it can be advantageous if the cover comprises a fabric-reinforced material.

If special demands have to be made on the resistance, a reinforcement of aramid fibers can be considered. In addition, numerous other textile fibers or glass fibers can be used that have a high Have tear resistance and - for mining applications - are as flame retardant as possible.

Particularly preferred for underground applications is the use of a grid-like fabric coated on both sides with flame-retardant and antistatic PVC as the covering material.

In a further embodiment of the invention it is provided that the casing consists of a weldable material which is connected to an essentially cylindrical shape by a weld which overlaps in the circumferential direction.

In this embodiment, a particularly simple manufacture of the sleeve is made possible by winding material of appropriate length, for example, around a rotatable frame and then overlapping, for example by means of a hot air weld. If the wrapping material itself is made of fabric-reinforced material, a cylindrical hollow body with an extraordinarily high tear strength results, in particular as a result of the relief of the seam, which results from the relatively high frictional resistance of the fabric used.

A shell that meets particularly high safety requirements in mining can be wound in a preferred development of the invention from three layers of the above-mentioned, lattice-like, PVC-coated fabric in a cylindrical shape, the outer edge being attached lengthways with a hot air weld becomes. For this purpose, the material is preferably wound onto the frame several times in the manner described above. In addition, this three-layer casing can be used for mining purposes Polyethylene film are inserted, which is commercially available in tubular form.

In an additional development of the invention it is provided that the sheath can be tied off at the ends by means of clamping devices and has at least one end of a feed hose which is guided through the clamping device into the interior of the sheath.

With this configuration of the pressure hoses, a particularly simple manufacture is made possible in this way, and a permanent and secure seal is achieved by means of a clamping device, a supply hose for supplying pressure being provided at the same time.

Alternatively, fastening means can be provided at the ends of the casing, to which a securing band running in the circumferential direction can be fastened.

This can be achieved, for example, in that the sleeve is turned inwards at its end and that metal eyelets are riveted through, through which a traction cable is passed, the two ends of which are fastened to one another with at least one cable clamp.

This results in a particularly reliable and easily producible closure of the sheath at its ends, the supply hose for supplying pressure being able to be led out in the middle.

In order to enable a high stability of the casing, in particular at its ends, and to make the casing as simple as possible, it is advantageous if only a single common feed hose for supplying the fluid into the interior of the chambers is provided.

In an advantageous embodiment of the invention, therefore, a distributor is provided at the end of the common supply hose within the casing, which can be designed, for example, as a T-piece, to which the supply hoses for the pressure hose and / or the individual chambers are coupled.

In this way, a simple connection of the pressure hose and possibly further individual chambers is made possible, only one supply line into the interior of the casing being required at the same time.

In a preferred development of the invention, the at least one pressure hose, which is folded up in the sleeve, is connected at both ends to a supply hose for supplying a fluid under pressure.

Thus, the pressure hose can be filled with compressed air from both ends at the same time, which has an overall advantageous effect on the speed and uniformity of the filling process. Furthermore, it is ensured in this embodiment that after the filling process has been completed, the pressure hose forms a self-contained, quasi-ring-shaped system which ensures optimum pressure equalization between the individual hose sections and thus largely avoids uneven stresses on different sections with an uneven load from the outside .

In a further preferred embodiment of the invention, the common supply hose is closed outside the casing by a pneumatic quick coupling, which is equipped with a speaking coupling element of a pneumatic line can be coupled, preferably by plugging.

Such a quick coupling, which is a common pneumatic part, has the function of a check valve which opens automatically when the corresponding coupling element is introduced and also closes again automatically when it is removed. In addition to simple handling, this has the advantage that not only filling, but also emptying of the chambers can be carried out without problems using this arrangement.

For filling, an adapter can also be provided outside the casing, to which several pressure cushions can be connected via quick couplings, so that several pressure cushions can be filled simultaneously with a single compressed air source. A pressure relief valve can also be integrated into such an adapter to ensure that the permissible pressure is never exceeded. Such a pressure relief valve can additionally be coupled with an acoustic warning signal in the event of a response. In addition, such an adapter can be adapted to the connection of an existing compressed air system, so that additional coupling pieces are not required.

In a further preferred embodiment of the invention, it is provided that the ends of the sheath are each passed through a ring, turned inside out over the ring and secured by means of clamping devices.

As a result, a reliable and permanent setting of the sheath at its ends is achieved in a particularly simple manner, the risk of damage being largely avoided and even at higher pressure loads due to the internal pressure of the chambers, slipping out of the clamping devices at the ends is avoided.

In an additional development of the invention it is provided that the at least one pressure hose is guided at least at one end over a hose with an upsetting and is secured against the upsetting by means of at least one cable tie.

In this way, the risk of damage to the pressure hose is largely ruled out, even when the internal pressure is high, and the cable tie is prevented from slipping off with the aid of the upsetting. In this way, a permanent and reliable sealing of the pressure hose can be achieved at its ends, a hose for pressure supply from the outside being integrated at the same time.

The hose on which the upsetting is provided in order to secure the pressure hose against it by means of a cable tie or the like is preferably made of PVC, an antistatic and flame-resistant version being preferred for mining applications.

The upsetting, which serves as an abutment for the cable ties, can be produced in this embodiment simply by heating and pushing the hose together. With a relatively large wall thickness of a few millimeters, the hose has sufficient stability to ensure an uninterrupted supply of the fluid into the interior of the pressure hose and also to serve as a fixing point for the binding. In an additional development of the invention it is provided that the pressure hose is sealed at least at one end in the area of the hose tie or the hose tie by sealing compound, in particular by silicone.

In this way, a secure and reliable seal can be achieved even in the case of wrinkles on pressure hoses of small wall thickness in the region of the binding, since fine capillaries and the like are securely closed. Furthermore, the additional sealing compound applied, which in the case of silicone solidifies into an elastic layer, increases the friction and improves the adhesion between the parts lying on top of one another, so that there is additional security against slipping off of clamping devices.

In a further embodiment of the invention it is provided, between a cable tie, which is fastened before the hose is upset, and the actual pressure hose via the underlying hose made of PVC or the like, which serves as a supply hose, from the outside an attachment hose or a winding made of insulating tape or the like.

Such an attachment hose or such a winding, which is turned inside out when the pressure hose is inflated and is compressed into a relatively short ring, prevents direct contact between the sensitive material of the pressure hose and the cable tie behind it, thereby reducing the risk of damage and the cable binder is relieved. For example, a hose with an inner soft plastic layer and an outer fabric-reinforced soft plastic layer in the manner of a garden hose can be used as the attachment hose. As already mentioned at the beginning, the pressure cushion can be used in a particularly advantageous manner for temporarily securing outbreaks in mining with shield removal in underground operation.

Without this requiring dangerous work between the removal and the unsecured slope, the prepared pressure cushion can be pushed into the cutout by means of a rod or the like and then filled with the fluid under pressure, that is to say preferably inflated with air .

In this case, it is expedient to use a plurality of envelopes in which a plurality of chambers are provided in the case of larger breakouts. In this way, cutouts of different sizes can be closed quickly and safely with a single design. After one or more sleeves have been inserted into the cutout, they are inflated until the cutout is largely filled and adequately supported. The shield cap can be moved back up to an almost horizontal position while the pressure hoses are being inflated. Alternatively, the shield cap can also be retrofitted with only partially inflated pressure hoses.

With this method, a particularly quick and safe temporary filling of outbreaks of the slope when removing the shield can be achieved. The risk of accidents is considerably reduced since dangerous work in the unsecured area is no longer necessary. Furthermore, the downtime is drastically reduced, since the filling of an outbreak can be achieved within a very short time. This is associated with considerable cost savings. Furthermore, the large amount of wood used in the conventional pillaring of the outbreaks is avoided, which in turn has corresponding cost advantages and relieves the underground supply routes.

Another advantageous application of the invention is for lifting and / or aligning heavy parts.

With the pressure cushion according to the invention, lifting or aligning even particularly heavy parts is now possible without the risk of bursting from large-volume, high-pressure pressure chambers having to be accepted.

Heavy parts can be aligned in a particularly advantageous manner with the pressure cushion according to the invention if the pressure of the chambers is regulated. Since such a pressure regulation can be achieved in a simple manner, for example with the aid of a pressure control valve, the arrangement can be used in a particularly simple and inexpensive manner. Furthermore, no heavy lifting equipment such as cranes or the like is required. Finally, pressure can be regulated very precisely and slowly, so that precise alignment of parts is made possible.

In this way, for example, opposite pipe ends of a pipeline can be precisely aligned with one another until welding is possible.

A pressure pad according to the invention can also advantageously be used as a sealing element, in particular when filling cavities with building materials which are liquid in the initial stage as a front head seal for sealing the cavity to the outside in order to enable backfilling with the building material or for sealing tunnels or gears. When using pressure cushions according to the invention as a sealing element, on the one hand, use as a so-called “front head seal” in underground mining or in tunnel construction is possible. During tunneling, the cavity between the extension and the rock can be closed off by one or more pressure cushions of a suitable shape which, when inflated with compressed air, seal between the extension and the rock. The cavity behind it can then be easily connected by a suitable hose or pipe connection with liquid building material, eg. B. be filled with concrete, even filling under pressure is possible.

After the building material has hardened, the pressure pads can be emptied again and generally used again.

Another possible application is the fast, temporary closing of tunnels, passages and the like, e.g. B. in underground mining to redirect the weather current (air flow), for example in the event of fire, gas development, etc. For this purpose, one or more pressure pads of the appropriate size are inserted and inflated in the relevant tunnel or corridor, if necessary using additional sealing material, such as Glass wool, silane or the like. The pressure pads get jammed due to the internal pressure and block the tunnel or aisle.

In a modification of this method, the pressure cushions according to the invention can be used for the rapid construction of a dam underground, the pressure cushions also serving as formwork. A seal is first created in the tunnel or aisle using one or more pressure cushions, possibly with the addition of a sealing material, such as glass wool or silane. Between this seal and a further, appropriately constructed seal, the building material can then be introduced through the fast inflated pressure cushions, which serve as formwork, are held in the tunnel or corridor from both sides. After the building material has fully hardened, the pressure pads can be pumped empty from both ends, salvaged and reused.

In a further advantageous embodiment of the invention, a pressure cushion according to the invention can be used as a splinter guard during blasting work or when disarming or detonating explosives.

When mining gold or diamonds underground, blasting is often carried out. In this case, a plurality of blast holes are usually introduced and ignited over a greater width in the mountains to be mined in order to facilitate the advance. Naturally, the miners must maintain a sufficient safety distance before ignition to avoid injuries from the blasting. Since underground explosive barriers which are sufficiently resistant to transport and handle are very complex, pressure cushions according to the invention offer particular advantages, since they can be inflated in a very short time, are extremely easy to transport and handle and have such a high level of resistance that they can mostly be used multiple times. The pressure cushions can be inflated individually or in groups in the form of a "barrier" in the immediate vicinity of the explosion point and can be jammed laterally and / or upwards and downwards by the internal pressure. As far as jamming upwards and downwards is possible, the pressure pads also act as a support element. As a rule, emptying, recovery and relocation are possible after the explosion. In addition, pressure cushions according to the invention can be used to catch extremely sharp-edged fragments, such as may arise during the disarming or detonation of explosive devices. For this purpose, pressure cushions are placed in front of the person or objects to be protected and fixed depending on the existing conditions. Splinters released during the explosion of the explosive body can damage the pressure pad, but cannot penetrate, so that the pressure pad practically has the function of "sandbags" that are easy to transport and ready to use.

It goes without saying that the features mentioned above and still to be explained below can be used not only in the combination indicated in each case, but also in other combinations or on their own without departing from the scope of the present invention.

Further advantages and possible uses of the invention result from the following description of preferred exemplary embodiments with reference to the drawing. Show it:

Figure 1 is a view of a pressure pad according to the invention in a simplified representation.

FIG. 2 shows a cross section of the pressure pad according to FIG. 1 in an enlarged representation;

3 shows a view of an end region of the casing according to FIG. 2 in a partially sectioned illustration (not to scale); Fig. 4 shows an end view of an end region of the casing in an alternative embodiment;

Fig. 5 shows a longitudinal section through the end region of a chamber according to FIG. 2 in an enlarged illustration;

6 is a partially sectioned, perspective view of a mining area in underground coal mining, in which the pressure pad according to the invention is used for temporarily supporting and pillaring an excavation;

7 shows a view of two pipe ends of a pipeline, each of which rests on a pressure cushion according to the invention, in a highly simplified representation;

8 is a side view of an envelope of the two pressure pads according to FIG. 7 in an enlarged and simplified representation;

Fig. 9 shows a schematic illustration of a pressure hose according to the invention, folded into 16 sections and placed next to and on top of each other in four sections, without the associated outer casing, in a view from the front and with an indicated air supply system;

Fig. 10 is a schematic side view of the pressure hose according to FIG. 9 from the left, in a reduced view.

11 shows a possible application of pressure pads according to the invention for the rapid construction of a dam, which is shown in section and 12 shows a further possible application of pressure pads according to the invention as a sealing element, here using the example of a front head seal when backfilling in line driving.

A pressure pad according to the invention is generally designated by the number 10 in FIG. 1. It has an outer shell 12 which is made of a fiber-reinforced, weldable material. The sleeve 12 has an essentially cylindrical shape and is closed at both ends with a clamping device 14, 16, a feed device 18 in the form of a feed hose being led out at one end, which is connected to a pressure source, not shown, e.g. a compressor.

The casing 12, which is provided for supporting and pillaring outbreaks of the slope end when removing shields underground, preferably has a length of 1.5 to 3 m and a diameter of approximately 0.6 to 1.2 m.

To produce the sleeve 12, material of appropriate length is wrapped three times around a rotatable frame and then welded lengthwise with an overlap of approximately 100 mm in length. The welding can be carried out as a hot air weld seam 20 with a width of approximately 40 mm, which has a high tensile strength. The resulting three-layer fabric has an extraordinarily high tear resistance. In addition, a polyethylene film is inserted into the resulting shell, which is available in a special design for the mining industry in the form of a tube. As can be seen in more detail from FIG. 2, a plurality of chambers 22 are provided in the casing 12, which are part of a pressure hose, as will be explained in more detail below.

In principle, it would be possible to design the chambers 22 as individual, completely separate and insulated chambers, so that if one or only a few chambers fail, the overall function of the arrangement is retained as a result of redundancy.

In the present exemplary embodiment, however, it is preferred, for the purpose of particularly simple manufacture and handling, to use the chambers 22 as partial chambers of a single pressure hose

form, which is inserted in a particularly folded form in the shell.

9 and 10 show such a pressure hose 110 in a schematic representation, which has been folded several times. The pressure hose 110 has a total of 16 chambers 120a to 120q, all of which are connected to one another and are formed only by the folding of the hose. The pressure hose 110 shown in FIG. 10 has been folded lengthways, in such a way that the individual sections in the inflated state correspond to the intended length of the sleeve 12 or 12 '. The folding takes place alternately from left to right and back again, so that the pressure hose 110 has approximately the shape of a folded heating coil. In FIG. 9, chambers connected to one another from the front by solid lines are indicated by solid lines, while chambers connected to one another from the rear are indicated by additional dashed lines. At the two ends 118, 119 of the pressure hose are two supply hoses 116, 117 connected, which are connected via a connector 24 in the form of a T-piece to a common supply hose 114, which is led to the outside through the casing (not shown in FIG. 9) and is terminated with a quick connector 112. The quick connector 112 serves as a check valve when the pressure hose 110 is filled with compressed air and no coupling piece is inserted into the quick connector 112. If such a coupling piece is plugged in, it automatically locks with the sinew connector 112 and enables both the filling of the pressure hose 110 by means of compressed air and an emptying of the pressure hose, if this is desired. 9, the direction of the air flow when the pressure hose 110 is filled is indicated by the arrows 122, 124, 126.

In the arrangement shown, the pressure hose 110 is filled from both ends 118, 119, so that a quasi-closed overall system is established via the pressure hose 110 and the connected supply lines 116, 117, which provides good pressure compensation even when the hose is fully folded under pressure from the outside. Overall, this arrangement enables the pressure hose 110 to be filled quickly and an even pressure distribution even when the pressure cushion is loaded from the outside in an uneven manner.

As can be seen in detail from FIG. 3, the sleeve 12 is bound together at both ends by means of a special clamping technique. At the open end shown in FIG. 3, a feed hose 19 is guided through a clamping device, designated overall by the number 16, into the interior of the sleeve 12, which ends in the distributor 24, which, as already explained with reference to FIG. 9, also acts as T-piece designed is. The ends of the folded pressure hose are connected to this distributor 24.

If damage or a certain pressure loss occurs in one of the chambers 22 in the inflated state, this in no way leads to a sudden escape of the air filling from the pressure hose, but rather, as a rule, only a gradual escape of air due to the folding of the pressure hose. so that the overall function of the pressure pad 10 is usually retained over a relatively long period of time and in any case a sudden release of larger amounts of compressed air and thus a risk to humans is excluded.

In addition, the mechanical stability of the sleeve 12 is so great due to the 4-layer structure described above and the special welding 20 in the longitudinal direction, which leads to a relief of the seam, that even in the event of a sudden escape of larger quantities of compressed air, which is practically impossible anyway bursting of the casing 12 is excluded from the chambers 22.

According to FIG. 3, the end 15 of the sleeve 12 is passed through a support ring 28 and then turned inside out over the support ring 28 and finally fastened by means of the clamping device 16 on the feed tube 19 by clamping. The clamping device 16 has a simple clamp 26 of a known type, with which the everted end 15 of the sleeve 12 is secured, so that there is a secure closure of the sleeve 12 at its end, with the ring 28 causing the clamping attachment to slide out is excluded and at the same time a secure integration of the feed line 19 is guaranteed. An alternative termination of the sheath 12 'at both ends is shown in Fig. 4. Here, the sleeve 12 'is turned in at both ends, and riveted with metal eyelets 27. After introduction of the pressure hose according to FIGS. 9 and 10, a thin wire rope 29 is passed through the eyelets 27 in the manner shown in FIG. 4, the sheath 12 'is pulled together and at these points with the protruding wire rope ends wrapped several times (not shown) before the wire cables 29 are secured with the aid of two cable clips (only one of which is indicated in FIG. 4 with the number 31). At one end, the common supply hose 19 for the air supply protrudes from the closed outer shell 12 '(likewise not shown in FIG. 4).

The design of the pressure hoses and the supply lines provided there for their pressure supply is of essential importance for the functionality of the support device.

The pressure hoses are made as seamless hoses from a film of polyterephthalic acid ester with a wall thickness of approximately 35 micrometers. Such hoses are commercially available.

The particular advantage of using polyterephthalic acid ester is its high tensile strength and the almost linear course of the stress-strain diagram.

In order to get by with as few folds as possible of a pressure hose within the casing 12 or 12 ', a pressure hose with a diameter of approximately 165 mm is provided, which consists of two film hoses of polyterephthalic acid ester which are pulled one above the other. The two-layer structure of the pressure hose on the one hand reduces the likelihood of damage to the inner film layer due to tiny foreign bodies inside the outer shell, and on the other hand any leaks that occur in one of the two films (which are occasionally but very rarely possible due to material defects) can also be airtight as a result sealed other layer of film does not affect the functionality of the pressure pad.

With such a dimensioning, the two-layer pressure hose is designed for a nominal operating pressure of approximately 0.5 bar and can be loaded up to a bursting limit of approximately 2.5 bar.

In this way, a pressure cushion with a supporting force of approximately 25 t per square meter at nominal pressure or approximately 10 t per square meter at maximum pressure can be realized. The envelope can have an inflated shape, for example, a length of about 160 cm and a diameter of about 80 cm. Such a pressure pad can be folded to about 60 x 50 x 20 cm and only has a weight of about 8 kg.

The manner in which the pressure hose is tied at both ends and provided with supply lines can be seen from the longitudinal section according to FIG. 5.

A hose 44, which is provided as a supply hose for connection to the distributor 24, consists of a PVC hose in an antistatic, flame-retardant design with an inner diameter of approximately 5 mm and a wall thickness of approximately 3 mm. This PVC hose 44 has in its central region a bulge 54, which was produced by heating and pushing the hose together. The pressure hose end 40 of the pressure hose 110 is over the PVC hose 44 and guided over the bulge 54 and secured on both sides of the bulge 54 by a cable tie 48, 50 each. A further cable tie 52 on the side of the bulge 54 facing away from the pressure hose 110 serves as an additional safeguard which, in addition to the two other, wider cable ties 48, 50, ensures a further security for the tightness of the binding.

In the area of the cable ties 48, 50, 52, a sealing layer 46 made of silicone is applied to the PVC hose 44 in order to ensure a perfect seal of the polyterephthalic acid ester film on the PVC hose 44.

Furthermore, a triple layer of wide insulating tape 41 is wound between the end 40 of the pressure hose 110 and the upsetting 54, which extends right up to the upsetting 54. This layer 41 rolls up like a ring when the pressure hose 110 is inflated and, on the one hand, prevents direct contact between the cable tie 48 and the film of the pressure hose 110 and, on the other hand, reduces the outward tensile forces on the cable tie 48 and additionally secures it, so that tearing open or chipping of the cable tie 48 is prevented.

The previously described tying technique for the end 40 of the pressure hose 110 is only used for the inner layer of the pressure hose 110. In contrast, with the outer layer of the pressure hose 110, it is sufficient to fill in a corresponding amount of silicone at the upset 54 and to place a cable tie here between the cable tie 48 and the upset 54, and between the cable ties 50 and 52 (not in FIG. 5) shown). An airtight seal is made on this Guaranteed and significant tensile forces on the outer layer of the pressure hose are not expected at this point.

The following procedure is used to manufacture the pressure pad described in detail above:

First, the overall 4-layer cover 12 or 12 'is wound in the manner explained above and the ends are preferably secured in the manner described with reference to FIG. 4 by means of wire ropes 29.

Subsequently, the prefabricated, two-layer pressure hose 110 is provided at both ends with supply hoses 116, 117 in the manner described above and then folded lengthways, as was explained with reference to FIGS. 9 and 10 and in this form with Teflon sealing tape fixed and inserted into the open outer shell 12 '. Such a folding of the pressure hose depending on the diameter of the sleeve 12 'and the diameter of the pressure hose 110 used is necessary in order to achieve the desired, roller-shaped configuration of the sleeve 12 or 12' in the inflated state. However, it is sufficient to fix the individual chambers 120a to I20q in this position only until the arrangement is first inflated, because experience has shown that the individual chambers then maintain the distribution once assumed. Of course, the chambers 120a to 12 Oq can also be fixed to one another in other ways. However, the use of Teflon sealing tape for the first fixing has advantages because of its special softness, which prevents damage to the pressure hose by the tape itself or by fragments remaining after a first filling. The low tensile strength of the sealing tape is also sufficient on the one hand to fix the chambers before the first filling On the other hand, Lind completely excludes any hindrance to the expansion of the chambers during filling.

After the folded tubular film has been inserted into the prepared casing 12 or 12 'and after the casing has been closed at both ends, the pressure pad can be filled and inflated via the common supply hose 19.

The connection of the pressure pad to an existing compressed air source takes place via a corresponding adapter to which the quick coupling 112 can be coupled. This adapter (not shown in the drawings) consists of three components. An input part is used to connect the adapter to the compressed air supply system used by the user and can be designed according to the resulting requirements (different sizes and shapes of the connections). As a second component, a distributor is integrated in the adapter, which is designed as a short piece of pipe, which can connect directly to the input part and is provided with one or more coupling parts to which the quick couplings 112 of different pressure pads can be coupled, so that the same several pressure cushions can be fed from one compressed air source at the same time. As a third component, the adapter contains a pressure relief valve which responds when the nominal pressure of the pressure hoses used is reached, that is to say in the present case at about 0.5 bar. The pressure relief valve can be coupled to a pressure reducing valve which reduces the pressure prevailing in the distributor to the desired pressure.

FIG. 6 now shows a mining space as is usual in underground coal mining. A hydraulic support frame 63, which can be pressed hydraulically onto the slope end 68 from below, serves to support the slope 68 and to pillar the excavation space is to support the mountains against the pressure acting in the direction of arrow 61 by means of a shield cap 64 which can be pivoted in the direction of arrow 65. A conveyor belt 69 serves to remove the coal which is obtained when a coal seam 67 is mined and to remove the remaining mining area. During excavation, 68 outbreaks 66 can occur in the not yet secured slope, which are temporarily supported with the aid of the pressure cushion.

In the conventional way, such outbreaks 66 have hitherto mostly been paved with the help of wood, which means that it took a long time from several hours to about a week and in particular led to an increased risk of accidents when working under the unsecured slope. In recent times, attempts have been made to fill with building materials with the addition of quick binders, which gives rise to problems similar to those with the pillar with wood, that is, in particular there is a high risk of accidents and high costs. In both cases there is no active setting force against the mountain pressure.

According to the invention, a suitably prepared pressure pad 60 of the construction described above, which can be acted upon by compressed air via a single common supply hose, is simply inserted into the cutout 66 by means of a rod or the like. Depending on the size of the outbreak, it may be appropriate to use several pressure pads 60.

Subsequently, the shield cap 66 is again moved into an approximately horizontal position and the pressure hoses of the pressure pillow 60 are pressurized with compressed air, which can be done via the aforementioned adapter with the aid of compressed air bottles or via a compressed air system laid underground. In this way, reliable temporary support of the excavation can be achieved within a short time, so that the dismantling can be continued.

7 and 8 show another possible application of the invention. Two pipe ends of a pipeline, which are indicated by the numbers 74 and 76, must be precisely aligned with one another before they are welded. For this purpose, each pipe end 74, 76 rests on a pressure cushion 70 according to the invention, which is supplied with compressed air via a compressor 72. The vertical position of the two pipe ends 74, 76 can now be changed in the direction of the arrows 78 via pressure control valves, not shown, in order to align the pipe ends 74, 76 with one another.

In this case, as shown in FIG. 8, a concave, outwardly curved support 80 can be provided on the outer shell, which is adapted to the shape of the tube.

FIGS. 11 and 12 show further possible uses of the pressure pads according to the invention as sealing elements.

11 shows the use of pressure cushions for the rapid construction of a dam for closing tunnels, passages and the like, e.g. B. in underground mining to redirect the Wetter¬ current, for example in the event of fire, gas development, etc. Pressure cushions of the appropriate size are inserted and inflated in the relevant tunnel or corridor, if necessary using additional sealing material, such as glass wool. The pressure pads jam due to their internal pressure and block the tunnel or aisle. Such a tunnel is shown in FIG. schematically shown section, which is generally designated with the number 130.

The dam basically consists of building material 136, which is held between two formworks, which are indicated by the numbers 135 and 137. A so-called dam tube 134 runs through the middle of the dam in the axial direction, for example in order to allow an inspection of the dam or the space behind it by a miner. The two formworks 135, 137 consist of a plurality of pressure cushions, which are indicated by the number 133 and which are arranged in such a way that each formwork 135, 137 completely closes the cross section of the tunnel 130, the dam tube 134 only sealingly in the middle is included. In order to improve the seal between the individual pressure pads 133, sealing material 138, such as glass wool, silane or the like, can also be used, as indicated in FIG. 11. Between the two sufficiently spaced formworks 135, 137, the building material 136, z. B. concrete introduced.

After the concrete has hardened, the pressure pads 133 of both formworks 135, 137 can be pumped empty, recovered and then reused. It goes without saying that the dam tube 134 is only optional and that the amount, size and shape of the individual pressure pads 133 can be adapted to the respective local conditions.

12 schematically shows the use of the pressure pads according to the invention as a front head seal for backfilling in line propulsion.

A tunnel 140, which is driven through a mountain 142, has an approximately semicircular cavity in cross section. This cavity must be secured to the interior of the tunnel 140 by means of a suitable formwork 144, which runs essentially parallel to the inner surface of the cavity, that is to say approximately semicircularly. Between the quickly inserted formwork 144, which may consist of appropriately shaped steel struts, and the mountain 142, the remaining cavity 146 must be filled as quickly as possible in order to avoid the yielding of the mountain 142 due to the mountain pressure as much as possible. For this purpose, a plurality of pressure pads 147 are introduced between the formwork 144 and the mountain 142 in order to seal the cavity 146 located behind it toward the front toward the front side. The pressure cushions 146, which expediently have a corresponding elongated shape, lie in a sealing manner between the mountains 142 and the formwork 144 during inflation, so that subsequently, for example, via a corresponding hose or pipe connection into the one behind them between the formwork 144 and the mountain 142 cavity 146, a building material that is liquid at the beginning, such as concrete, can be introduced.

After the building material has hardened, the pressure pads 147 can be pumped empty, recovered and reused.

Claims

1. pressure pad with an at least partially flexible envelope (12, 12 '), within which a plurality of chambers (22, 120a to 120q) is provided, with a device (18, 24, 72, 112, 114, 116, 118) for supplying a fluid into the interior of the chambers (22, 120a to 120q) under pressure to support the casing (12, 12 ') against external pressure loads.

2. Pressure pad according to claim 1, with at least one pressure hose (110) which is divided into a plurality of sections through which at least some of the chambers (120a to 120q) are formed.

3. Pressure pad according to claim 2, wherein the pressure hose (110) is folded several times.

4. Pressure pad according to one or more of the preceding claims, wherein the device (72) comprises a Regelein¬ device for pressure regulation of the fluid.

5. Pressure pad according to one or more of the preceding claims, in which the chambers (22, 120a to 12Oq) consist of a high-strength material, in particular of polyterephthalic acid ester.

6. Pressure pad according to one or more of the preceding claims, in which the pressure hose (110) is designed as a two- or multi-layer pressure hose.

7. Pressure pad according to one or more of the preceding claims, wherein the sheath (12, 12 ') comprises a fabric-reinforced material.

8. Pressure pad according to one or more of the preceding claims, in which the sleeve (12, 12 ') consists of a weldable material which is connected to a substantially cylindrical shape by a circumferentially overlapping weld (20).

9. Pressure pad according to one or more of the preceding claims, in which the sheath (12, 12 ') can be tied off at the ends and at least one end has a common supply hose (19, 114) which is guided into the interior of the sheath (12, 12') ) having.

10. Pressure pad according to claim 9, in which at the ends of the sleeve (12) clamping devices (14, 16) are provided for tying the ends.

11. Pressure pad according to claim 9, in which fastening means are provided at the ends of the casing (12 '), to which a securing element running essentially in the circumferential direction can be fastened.

12. Pressure pad according to claim 11, wherein the sheath (12 ') is turned in at its ends and is provided with eyelets (27) through which a traction cable (29) is guided, the both ends are fastened together with at least one rope clamp (31).

13. Pressure pad according to one or more of the preceding claims, wherein the at least one pressure hose (110) at both ends (118, 119) has a supply hose (116, 117) for supplying a fluid under pressure.

14. Pressure pad according to claim 13, in which the supply hoses (116, 117) are connected via a distributor (24) within the casing (12, 12 ') to the common supply hose (19, 114) which is passed through the casing (12, 12 ') is led to the outside.

15. Pressure pad according to claim 14, wherein the common supply hose (19, 114) outside the shell (12, 12 ') is closed by a pneumatic quick coupling (112) which can be coupled to a corresponding coupling element of a pneumatic line.

16. Pressure pad according to one or more of the preceding claims, in which the ends (15) of the sheath (12) are each passed through a ring (28), are turned inside out over the ring (28) and by means of a clamping device ( 16) are secured.

17. Pressure pad according to one or more of the preceding claims, in which the at least one pressure hose (110) is guided at least at one end (40) via a hose (44) with an upsetting (54) and by means of at least one cable tie (48, 50 , 52) is secured against upsetting (54).

18. Pressure pad according to one or more of the preceding claims, in which the at least one pressure hose (110) is sealed at least at one end (40) by sealing compound (46), in particular by silicone sealing compound.

19. Pressure pad according to one or more of the preceding claims, in which between the pressure hose (110) and the upsetting (54) a piece of hose or a winding (41) made of insulating tape is applied to the end (40) of the pressure hose (110).

20. Pressure pad according to one or more of the preceding claims, wherein the chambers (22, 120a to 120q) are coupled to at least one pressure relief valve.

21. Use of a pressure pad according to one or more of the preceding claims for filling an outbreak (66) of the hanging wall (68) underground.

22. Use of a pressure pad (70) according to one or more of claims 1 to 20 as a hoist for lifting and / or aligning parts (74, 76).

23. Use of a pressure pad according to one or more of claims 1 to 20 for temporarily supporting a mountain when expanding a gallery.

24. Use of a pressure pad according to one or more of claims 1 to 20 as a sealing element, in particular when filling cavities (146, 150) with building materials (136) which are liquid in the initial stage as a head seal to seal the cavity (146) to enable backfilling with the building material (136) or to seal tunnels (130) or passageways.

25. Use of a pressure cushion according to one or more of claims 1 to 20 as splinter protection in blasting work or in the defusing or blasting of explosive material.