The invention relates to a pressure device for use in securing or sealing bodies against leakage paths, in particular round bodies such as tubes and tube couplings, as well as a method for it. The invention furthermore relates to a pressure body for use in such a device.

Tube couplings, including flange adapters between tubes of the same diameter, tubes of different diameters and of tubes with a valve box, etcetera, particularly when it regards gas or water mains in residential areas, need to be sealed reliably and permanently. It is usual to have the tubes or tube extend in a house and arrange an annular rubber sealing between the tube or tubes and the house. The sealing ring is then pressed in axial direction. It is known to use the inclined planes in order to realize a wedging action.

In such connections provisions to resist tensile forces (tensile security) may also be included, for preventing a mutual, separating movement of the coupled elements. Said provisions to resist tensile forces might also be provided without sealing, where sealing is not needed. An example of this is shown in European patent application 0.168.069, in which a tensile ring is shown, having a wedge-shaped cross-section and which is interrupted in circumferential direction.

Furthermore a sealing ring is known, having a wedge-shaped cross-section and provided with two series of radial notches lying off-set with respect to each other in both opposite axial ring planes.

In all embodiments a lot of force has to be exerted when arranging the sealing ring and/or tensile strength ring, on order to displace/deform or shift the material of said ring (s) to a functional position, in axial and possibly in circumferential direction.

Fitting in difficult to reach places, such as underground, or below groundwater etc., therefore often causes problems. As a result a coupling arrangement, sealing and/or tensile security is not realised in the proper manner, resulting in a dangerous situation.

An object of the invention is to provide a pressure device for sealing, tensile security and/or coupling, which can be arranged quickly and with less force in a reliable and simple manner.

From one aspect the invention to that end provides a pressure device for engaging bodies for connecting, in particular round bodies, such as tubes, comprising a pressure body having a-considered in cross-section-relatively rigid portion and having one or several pressure planes and comprising means for bringing and keeping the pressure planes pressed against the surface of the body to be connected, the pressure body having one or several counter pressure planes active counter to the pressure planes, having two side planes that are active in the opposite direction and- considered in cross-section-being rotatable or deformable while altering the distance between the side planes in order to move the pressure planes and the counter pressure planes with respect to each other in radial direction.

When fitting the pressure body can be placed in a simple manner and after that be rotated and deformed in cross-section in order to press against the surface of for instance the tube, for sealing or clamping. A more or less axial approach of both side planes/counter pressure planes as if of its own accord results in a reduction-in case of a sealing around a tube-or

increase-in case of a (rare) placement in a tube-of the curve on which the pressure planes are situated.

From another aspect the invention provides a pressure device for engaging bodies for connecting, in particular round bodies, such as tubes, comprising a pressure body having a-considered in cross-section-relatively rigid portion and having one or several pressure planes and counter pres- sure planes that are active in the opposite direction to it, and comprising means for bringing and keeping the pressure planes pressed against the surface of the body to be connected, which means are active by increasing the radial distance between the pressure planes and the counter pressure planes.

From yet another aspect the invention provides a pressure device for engaging bodies for connecting, in particular round bodies such as tubes, comprising a pressure body having a-considered in cross-section-relatively rigid portion and having one or several pressure planes which in the initial position define a circumferential track having a size, and comprising means for bringing and keeping the pressure planes, in the active position, pressed against the surface of the body to be connected, which means are active by altering, in particular reducing, the size of the circumferential track by deformation of the cross-section of the pressure body.

Preferably the side planes and the counter pressure planes are formed on a circumferential, continuous or composed body, so that the pressing forces can be generated over the circumference in a evenly divided manner.

Preferably the pressure body has a substantially V-or U-shaped cross- section, the pressure planes preferably being situated on the outer side of the base of the V or U. The side planes and the counter pressure planes are then present on the arms of the V or U, in which way a favourable design has been obtained from a stability point of view.

The pressure body can be formed as one continuous, circumferential unity, which may or may not have been provided with notches. Considering the high mould costs and the application possibilities depending on the size this, however, is particularly advantageous in case of large series.

Otherwise it is preferred that the pressure body is built up from a number of segments placed against each other in circumferential sense or segments that are held spaced apart. In this way the pressure body can be assembled at the desired circumferential size. Keeping an extensive stock of various ring diameters is no longer necessary.

Preferably the pressure planes are situated at the radially innermost side of the pressure body. They are then arranged to engage on the outer surface of the-for instance-round body to be connected, such as a tube. Because of the radially inward forces and the relatively small pressure surface the conditions for sealing are more favourable.

Preferably the pressure body is provided with more or less rigid portions which can be rotated with respect to each other. Thus the deformation is concentrated in a certain area, as a result of which the controllability is increased and the well-functioning at several times of re-use is ensured.

Alternatively seen, the pressure body preferably is provided with an internal hinge.

In case of the known rubber sealing rings it is a problem that when compressing in the plane of the cross-section deformation is hardly pos- sible, but the material does have to go somewhere when reducing the circumference of the ring. The notches in the aforementioned sealing ring here offer some improvement, but still high frictional forces will have to be overcome in circumferential direction and in axial direction.

From a further aspect the invention improves on this, because the pressure body at least at the location of the pressure planes is coated with a ring or annulus of rubber or similar material, which has been secured to it in a in circumferential direction tensioned condition.

Here, use is made of the fact that (solid) rubber and the like can be stretched but cannot be compressed. Prior to fitting the pressure body-in case of an outer engagement of a tube-is enlarged in diameter, counter to the tensile tension of the rubber. After the initial placement the tensile tension or pre-stress forces will be released, and the pressure planes will as if of their own accord be pressed against the tube surface. The side planes will approach each other of their own accord as well. Little to no tension force will have to be exerted in axial direction on the side planes. In circumferential direction the material need not or hardly be compressed, so that the forces for having the material deflect from a circumferential line will remain limited.

In case of an outer engagement of a tube and a continuous circumferential pressure body said body can be designed at the smallest size possible and then be used in a large range of tube diameters. With larger diameters the recoil strength will accordingly be larger.

At the pressure side, the pressure body can be entirely coated with a rubber sleeve, for instance by immersion in a bath or by covering.

In particular in case of a body built up from segments, it is preferred that the pressure body has at least one circumferential support body for the bond. The support body preferably is made of a shape retaining material, and preferably situated at the side of the counter pressure planes. Further- more the support body preferably has a fixed circumferential length, so that the (radial) location of the portions of the pressure body connected to it is determined. Preferably such a support body is provided in each arm of

the (segment of the) pressure body.

From a further aspect according of the invention the fitting of the pressure device can be facilitated when the pressure body has a prestress towards the active position, which preferably is realised by means of an elastic material in or on the pressure body. The aforementioned lining may have such a function, if circumferential.

From a further aspect the invention provides an assembly of a pressure device according to the invention and a rigid body, for instance a round body such as a tube, the pressure body with the counter pressure plane bearing against rigid placement means, such as placement rings, which in radial direction are stationarily arranged with respect to the body.

In a further development such an assembly is provided in which a second comparable assembly is additionally placed in line, the middle placement means or placement rings forming a bond with each other and both other placement means or placement rings being arranged for controlled, axial displacement. Starting from the principles of the invention a tube coupling is thus provided which can be mounted quickly and is reliable.

Alternatively the outer placement means or placement rings may form a connection with each other and both other placement means or placement rings have been arranged for controlled, axial displacement.

As mentioned the object may be sealing. In that case the pressure body, provided with a sealing material, will form a sealing for a leakage path for fluid, such as water or gas, along the surface of the round body. Alter- natively or additionally the pressure body may have a tensile security function. To that end the pressure planes may be provided with friction increasing means or profiles, such as tooth-shaped ridges. The design of the pressure device according to the invention however also renders it

effective in a protection against axial movement under the influence of pressure. In a combination of sealing and tensile/pressure security the pressure plane may be composed, one part being formed by elastic material and another part being formed by a friction profile.

From yet another aspect the invention provides a method for coupling two tubes that are substantially in line with each other, a sealing jacket being placed internally or externally around the coupling area, a pressure body according to the invention being placed at two rings of the jacket axially spaced from each other, with the side plane and counter pressure plane being supported in the jacket, and a placement ring being placed on both other side planes and counter pressure planes and subsequently the axial distance between the placement rings and the jacket rings situated near them being reduced, in order to thus reduce the distance between the side planes and sealingly pressing the pressure planes against the surface of the tube concerned.

In a development the placement rings are situated at a fixed axial distance from each other and forming a unity with the jacket, whereas on the jacket, axially within the placement rings, two rings are provided which can be adjusted in axial direction.

In an alternative development the jacket rings are fixed with the jacket and the placement rings are adjustable in axial direction.

Preferably the jacket has such a relative diameter, that some tilting of a tube is possible, the fact that the pressure planes will have a small diameter in axial direction also contributing to that end.

Preferably the forcing towards each other of the jacket ring and the placement ring takes place under the influence of a prestress in the pres- sure body concerned.

Furthermore it is preferred that the location of the placement rings with respect to the jacket is adjusted, preferably with an adjustment bolt, quick- acting clamp or swivel.

The invention will now be elucidated on the basis of a number of exemplary embodiments shown in the drawings, in which: Figure 1 shows a partial cross-section of the tube coupling, in which an exemplary embodiment of pressure devices according to the invention is included; Figures 1 A and 1 B schematically show a coupling comparable to the one of figure 1; Figure 2 shows another example of a pressure device according to the invention; Figures 3A-C schematically show the operation of a pressure device according to the invention; Figures 4A-4K respectively show a number of examples of pressure devices according to the invention, destined for sealing and/or securing; Figure 5 shows a further exemplary embodiment of a pressure device according to the invention, designed double for securing and sealing; Figure 6 shows two further examples of couplings of hollow bodies, but now with internal arrangement.

The tube coupling 1 of figure 1 ensures sealing coupling of two tubes 2 and 3, which have different diameters. Around the tube 2 a rigid circum- ferential placement ring 5 has been placed, and around the tube 3 a com-

parable placement ring 6. The intermediate space in axial direction between the tubes 2 and 3 is bridged by a rigid jacket 4.

The placement ring 5 is provided in one or more of lips 7, having bolt holes 8. In a comparable manner the placement ring 6 is provided with one or more lips 9, having bolt hole 10. The jacket 4 in a comparable manner is provided with lips 11 and 13 having bolt holes 12 and 13, respectively.

The placement ring 5 defines a seat 15, the placement ring 6 a circum- ferential seat 16, whereas at both ends with edges 50 and 60 the jacket 4 defines comparable circumferential seats 17 and 18. The seats 15,16,17 and 18 form a support for pressure bodies 19 and 20 according to the invention, in axial and in outward radial direction. As schematically shown, said pressure bodies are built up from-at least as considered in cross- section-two more or less rigid arms 31, which in the middle are hingeably connected to each other. At the radial inner side a lining 29 has been provided, which functions sealingly and may for instance be made of rubber, or another (elastic) material of comparable sealing properties. When in the situation shown in figure 1 bolts 21 and 22 have been arranged, the placement ring 5 and the placement ring 6 can thus be axially moved towards the jacket 4 in the direction A and B, as a result of which the seats 15 and 17 and 16 and 18 are forced towards each other in axial direction. The ends of the arms 31 of the pressure bodies 19 and 20 will also be forced towards each other, but with their arm ends forming-axially oriented-side planes and-radially oriented-counter pressure planes, rotate in the seats 15-18, as a result of which the hinges with which the arms are connected to each other will radially be forced to the inside in the direction C and D. In this way also the plane 28 with which the sealing is forced against the tubes 2 and 3 is also firmly pressed for optimal sealing.

In figure 1 it is also shown that because the diameter of the jacket 4 of the ring 5 and/or ring 6 is/are wide with respect to the diameter of the tubes 2

and/or 3 and because the pressure planes on the tubes are relatively narrow, the tubes can be tilted a little, so that too large tensions in the tube line connected thereto can be prevented and the placement of the coupling is facilitated, or either the line can be placed at a desired small angle. Then as well a tilting is possible as a result of settings, as a result of which too large tensions are prevented.

In figure 1A and 1B all this is further illustrated, in which it can be seen that the pressure bodies 19'and 20'can be built up from a number of seg- ments placed against each other or close to each other in circumferential sense. In order to keep the segments together, circumferential rings 41 a, b can be provided, which in this case extend through the ends of the arms 1.

The pressure body 30 shown in figure 2 is formed as one unity from for instance nylon, and comprises two relatively shape-retaining annular por- tions 32a, 32b, which form support bodies and from which arms 31 a, 31 b extend towards each other, which arms are connected to each other by means of bridges 36. Between the arms and the bridges, considered in circumferential direction, slit-shaped spaces are present, in order to provide space for approach of the arms and the bridges when they are moved radially inwards. In order to prevent ruptures said intermediate spaces end in holes 34a, which via widening slits 33a debouch in slits 37 between the bridges.

Because of their thickness and shape, a cavity 39 being defined, the bridges 36 can be considered hinges with which the arms 31 a and 31 b are connected to each other. The rings 32a, 32b are provided with side planes 35a, b and support and counter pressure planes 35c, 35d.

In figures 3A-C the principle of the operation of the pressure body accor- ding to the invention is shown. A (segment of) pressure body 130, is shown which is provided with two arms 131a, 131b made of relatively

rigid material, which are connected to each other by means of hinge 136.

A continuous rubber lining or coating 140 has been applied over the pressure body 130-which functions as a frame-, which lining is turned over the ends of the arms 131 a, 131 b with the portions 135a, 135b. At the level of the hinge the lining 140 is thickened, and there forms a pressure surface 138. It will be understood that a circumferential, con- tinuous series of the segments shown can be formed, in which the sealing lining is continuous.

The pressure body 130 built up from said segments, has been placed in the tube coupling of figure 1. There the seats 15-18 ensure that the support surface, indicated by T in figure 3a and 3B, is stationary considered in radial direction. When the ends of the arms 131a, 131b are moved axially towards each other in the direction A, the pressure plane 138 in the direction C will be urged radially to the inside, to reach the situation shown in figure 3B. The internal radius defined by a circumferential series of pres- sure planes 138 of R1, will then be reduced to R2 (also see figure 3C).

In the figures 4A-4E a number of segments which can be incorporated in a pressure body according to the invention are shown, in which it will be understood that the rubber lining is circumferential again and several segments can be connected to each other into a circumferential series.

In figure 4A the segment 230 is shown, comprising two arms 231 a, 231 b, which are connected to each other by means of hinge 236. A rubber lining 240 has been arranged around said arms, possibly under stretch in axial direction. It is drawn that a metal part extends through the ends of the arms, which part is annular and keeps consecutive segments 230 in circumferential series with each other. The segments may be abutting with their arm ends, but alternatively spacers can be arranged on a continuous ring, so that the ends of the consecutive segments are kept at the correct distance from each other without them abutting each other directly.

An alternative for attaching the rubber sleeve 24 at the arm ends and connecting the segments to each other is, instead of the rings accom- modated in the arm ends, designing the arm ends in a narrowed manner and clamping a circumferential, in cross-section U-shaped steel ring over the narrowed part. The narrowing is such that the outer surface of the steel ring fluently changes into the surface of the arms. The rubber can then be attached over the arm end without a possibility of its getting damaged.

It will be understood that the possible stretch with which the rubber sleeve 240 is placed over the arm ends will not be so large that the hinge motion between the arms is extremely impeded. After all, when the arms are approaching the length between the arm ends will be enlarged at the radial inner side.

A special aspect is that the rubber sleeve can be arranged on the pressure body according to the invention by (possibly also) stretching it in circum- ferential direction. If necessary provisions that are not shown can be made to keep the arm ends in the (shown) situation prior to placement at a distance from each other. After placement said provision or locking can be removed, after which the rubber sleeve at the location of the pressure plane 238 would want to tend back to its original situation, and will contract, as a result of which as it were the arms will hinge along of their own accord and the pressure plane 238 will be moved radially inwards. The arm ends are kept in their places in radial sense by the circumferential rings, which function as-internal-support body.

By using a relatively rigid yet as a result of the hinge freedom deformable body, formed by both arms and the hinge connection between them which may or may not be 100%, and the rubber sealing part, a well-functioning, easy-to-install and in the long run reliably functioning sealing is obtained. The rigid portion or the rigid portions of the pressure body here as it were

form a frame for the rubber sealing part, which frame can be deformed in a controllable manner.

In figure 4B an alternative embodiment is shown, which for a large part corresponds to the one of figure 2. Here the consecutive segments thus form a unity with each other. In the middle the pressure body 330 has been provided with a hinge forming bridge 336, in which a rubber lining 340 has been applied, which in a thickened portion forms pressure plane 338. In figure 4B it is shown that the rubber sleeve 340 not necessarily extends over both arms, yet it is possible (portion 340').

In figure 4C a pressure body 430 is shown, of which the arms 431 a, 431 b have unequal lengths.

In figure 4D a pressure body 530 is shown, of which the arms are con- nected to each other by means of two hinges 536a, b, whereas also the pressure plane 538 has two portions. The hinges 536a, b are hingeably connected to each other by means of intermediate part 537.

In figure 4E a pressure body 630 is shown, which like in figure 4D has two hinges 636a, b for connecting both arms to each other, a pressure plane being formed by a series of saw teeth, arranged on a circumferential ring, provided with axial/radial ribs 637 and on which each time two arms 631 a, b are hingeably attached.

In figure 4F-J schematic examples are shown of (segments for) pressure bodies according to the invention, which are only destined for securing or coupling without a sealing being necessary.

In figure 4F the pressure body 730 is shown, which in a hinge 736 has been provided with a series of gripping teeth 739.

In figure 4G the pressure body 830 is shown, of which one of the relatively rigid arms, that are hingeably connected to each other, has been provided with a series of teeth 839 active in one direction. By rotation of the arm at axial approach of the arm ends the teeth as it were automatically end up in the active position.

In figure 4H a pressure body 930 is shown, which is provided with two hingeably connected arms, which at their ends are provided with series of engagement teeth 939, which when hinging during placement are moved towards each other and into an engaging position.

In figure 41 an alternative shape of the pressure body 230'is shown, consisting of two synthetic arms 231 a', 231 b'put or snapped together in an interlocking manner at the location of the hinge, which arms in the arm area are provided with grooves 241 a', 241 b'opening to the pressure side. In said manner each composed pressure body can easily be assembled on a rigid ring with the grooves 241 a', 241 b'. The pressure bodies 230'can, in the same manner as described above, be surrounded at the pressure side by a rubber sleeve.

In figure 4J the same pressure body 230'is shown accommodated in a fixing arrangement, in which the steel intermediate member 240'at the pressure plane 238'is provided with toothings 239', in which the pressure plane 238'is concave (not shown) in order to better fit a tube to be fixed, when its outer surface is engaged. On either side the intermediate member 240'is provided with little pins 262'on which each time a pressure body 230'as shown in figure 41 is arranged, by pinning it with the hole 261' onto the little pins. Between both pressure bodies 231'synthetic distan- cers 260'are also arranged. In case of synthetic tubes, one would like to have them engage around the entire circumferential surface. With steel tubes fewer of such toothed blocks will possibly suffice for reliably en- gaging the tube.

In figure 4K a (segment of a) pressure body 1030 is shown, which com- bines sealing and securing with each other. By means of hinge 1036b the arm 1031b is connected to intermediate part 1037, with which via hinge 1036a the other arm 1031 a is connected. The intermediate part 1040 has an engagement toothing 1039, whereas over the arm 1031b an in circum- ferential direction circumferential rubber sleeve 1040 has been arranged, which in axial direction adjacent to the toothing 1039 provides a rubber sealing plane 1038.

A combined securing and sealing can also be provided with the arran- gement shown in figure 5, which is somewhat similar to the one of figure 1, in which the one pressure body 730 serves for securing the one tube and the pressure body 130 serves for forming the sealing along the other tube.

Advantageous in this case is also that the lips through which the bolt 21' extends are in line with each other, so that less bolts will suffice and both pressure bodies can be tensioned with one single action.

In figure 6 in the upper part, a use of a pressure device according to the invention is shown, in which it is circumferential yet radially active to the outside. Here the pressure device is for instance placed in the inside of a round body, where placement of the pressure body in the passage is not problematic as it for instance does not fulfil a transport function for liquid or solid matter.

It will be understood that the shown parts in most cases are circumferen- tial.

In the upper part of figure 6 the circumferential bodies 1102 and 1103 are shown, against the inner surfaces of which two circumferential pressure bodies 1130 have been placed, which have been provided with rubber

sleeves 1140 having pressure planes against the inner surfaces. The pressure bodies 1130 are urged to the outside with their hinges, in a manner comparable to the one shown in figure 1. Thus the rings 1105 and 1106 are urged towards each other and to the support rings 1150 and 1160, which are fixed on the jacket 1104, by means of a bolt which has been extended through the openings 1122. It will be understood that a number of bolts will be used in circumferential sense. Other tensioning means, such as a swivel construction, are possible too.

In the lower part of figure 6 a comparable arrangement is shown, but now the rubber sleeves 1141'of both pressure bodies 1130'are formed as one unity by means of sleeve portion 1170. The placement rings 1105'and 1106'are now formed on one and the same jacket body 1104', but now two axially slidable open rings 1170a, b have been arranged on it, which are each fixedly connected with support rings or-shoulders 1150'and 1160'. By urging the rings 1170a, b away from each other, for instance by driving a number of wedges in between them, the arms of the pressure bodies 1130'are urged towards each other and the pressure planes of the sealing sleeves 1140'are firmly pressed against the surface of the bodies 1102 and 1103.