EP0461336A2 - Method of making a pressure chamber resisting against internal detonations, and pressure chamber made by this method - Google Patents

Abstract

A pressure chamber resistant to internal detonations, e.g. For the security check of flight luggage, of cylindrical shape with end walls, individual parts are assembled on site without welding. The cylindrical wall of the pressure chamber (1) consists of curved plates (6a, 6b, 7a, 7b, 8a, 8b) which have folds (25, 26) undercut on the back on their edges. The connection along the joints is made by means of U-shaped connecting strips (27) with a dovetail groove, which encompass the folds, and wedge-shaped inserts (29) inserted into the joint from the other side; which are clamped against the connecting strips (27) and press the back of the fold sealing against the flanks of the dovetail groove. <IMAGE>

Description

The present invention relates both to a method for producing pressure chambers constructed from elements with the ability to withstand the force of an explosive charge detonating inside the chamber when assembled, and to the pressure chamber produced by the method described.

In normal airfreight traffic, increasingly larger quantities of air cargo packed in containers are transported, which makes it difficult to carry out individual checks on the cargo. In addition, air cargo is often transported as part loads in normal passenger traffic. Several aircraft have recently been blown up by terrorist attacks, with strong evidence suggesting that the explosives used were carried in the holds and detonated by pressure or pressure / time-triggered devices.

Since the cargo holds of an aircraft are outside the pressurized cabin of the passenger area, the air cargo is exposed to the changes in air pressure depending on the altitude. A triggering device controlled by the change in air pressure, e.g. detonating an explosive charge after a certain drop in pressure, i.e. when the aircraft has reached a certain altitude, is likely to be a relatively simple construction task. Finding such an explosive charge in a large quantity of goods, on the other hand, creates considerably more difficulties, especially since such an explosive charge hardly needs to have larger dimensions than a normal novel.

Because of the repeated attacks against aircraft was in the latter The need to subject the air cargo to a simulated flight in a pressure chamber at all of the larger air cargo terminals is increasingly discussed before it can be loaded into a passenger plane in normal scheduled traffic.

Such a pressure chamber has to meet, among other things, the requirements to withstand partial negative pressure corresponding to at least normal flight heights and partial excess pressure due to an internal detonation of such strength that it could explode an aircraft from the inside. This means that only a combined vacuum / pressure chamber can meet these requirements.

Hyperbaric chambers, i.e. rooms resistant to internal detonations, have so far been built almost without exception as earth bunkers, but in recent years much more practical metal structures with very promising properties have also been developed.

Some such constructions are described in Swedish patents 81 05585-7, 83 05758-8 and 84 00003.

Hyperbaric chambers made of metal are precisely calculated, welded shell constructions. However, the satisfactory function of such constructions presupposes that all welding work is carried out and checked with the highest degree of accuracy and care. Since a vacuum / pressure chamber must be able to hold fully loaded air freight containers, normally net pack pallets of the same cross-section as the fuselage, for the described purpose, the vacuum / pressure chamber has considerable dimensions. This in turn means that the transport of a finished vacuum / pressure chamber from the place of manufacture to the intended air freight terminal can be very difficult, while on the other hand a partial implementation of the necessary qualified welding work on site greatly increases the assembly time.

The present invention relates to a method for producing pressure chambers with the ability to withstand the force of an explosive charge detonating inside the chamber, wherein the production at the place of manufacture can comprise relatively small elements, based on the overall dimensions of the finished pressure chamber, which can then be carried out at the installation site without any welding work can be assembled into a finished pressure chamber. The finished pressure chamber is also part of the invention.

The type of pressure chamber in question must not only meet the requirements with regard to resistance to both negative pressure and internal detonations, but must also withstand strong vibration stresses, since it can be expected that vibration tests with negative pressure will also be included in the scope of the test in the future.

The present invention thus relates to a method for producing pressure chambers constructed from elements and to the pressure chamber produced by this method, which resists internal detonations and can be built in a factory in such a way that no welding work is required at the installation site. From the outside, the pressure chamber is of a known configuration with a cylindrical shape and transversely closing, stably reinforced and fully or partially openable end walls. The process for producing the pressure chamber according to the invention and the finished pressure chamber are characterized in that the cylindrical part of the pressure chamber is constructed from bent plates or jacket sheets adapted to the desired shape of the chamber. The jacket sheets are joined together in the longitudinal and transverse directions in a special way and are connected to one another by connecting yokes which are arranged lengthwise with and above the respective joints and are laid in the longitudinal direction of the joints. The connecting yokes are provided with two longitudinal, angularly opposing clamping surfaces. The assembly is carried out in such a way that these clamping surfaces against the first rabbet surface running along the joint edges and forming an acute angle with the adjacent broad side of the casing sheets, issue. A tight fit between these first fold surfaces or fold backsides and the clamping surfaces is achieved by inserting intermediate pieces between the fold front surfaces of the jacket sheets forming the joint edge and tightening them with screws on the connecting yokes, thereby exerting a wedge effect on the jacket sheets when the screws are tightened apart. The intermediate pieces and preferably also the front surfaces of the folds of the jacket sheets are designed with oblique flanks; preferably, the intermediate piece to be inserted from the opposite side of the connecting yoke has a trapezoidal cross section.

The dovetail groove of the connecting yoke has its smallest width on the side facing the casing sheets, and this smallest width is so matched to the greatest width of the flanges of the pushed-together casing sheets that the connecting yoke can only be pushed over the folds as long as the intermediate piece is not inserted .

In the method according to the invention, the joint edges of the cladding sheets are first arranged close to one another, the connecting yoke is placed on top and then the cladding sheets are pushed apart again, to the extent that the intermediate piece is inserted between the joint edges from the side opposite the connecting yoke and then with screws in Connection yoke can be attached. By tightening the screws, i.e. by forcing the intermediate piece closer and closer to the connecting yoke, the joint edges of the cladding sheets are simultaneously pushed apart by a wedge effect, so that by gradually tightening the evenly distributed screws along the joint, possibly supplemented with a suitable sealing compound or gasket , receives a tight joint. Characterized in that the rear or first folded surfaces of the cladding sheets form an acute angle with the adjacent wide sides of the cladding sheets and the clamping surface of the connecting yokes are adapted to the folded surfaces, the combined joint receives a dovetail-shaped cross-section which cannot diverge as long as the intermediate piece is in its installed position between the joint edges of the casing sheets. Advantageous features of the invention are also the end wall parts with their openings, which are manufactured in the factory, at least one shorter, complete jacket piece, ie with a full circumference, being welded to the end wall part. This complete jacket piece is provided on the end side with corresponding folds as with the other jacket sheets, and as a result the end wall parts can then be easily connected to the cylindrical part constructed from assembled jacket sheets.

The cylindrical part of the pressure chamber is advantageously carried out in a two-shell construction, and then the folds and connecting yokes are advantageously directed towards the inside of the chamber, with the smoothest possible inside and outside surfaces being obtained with appropriately dimensioned intermediate pieces.

If the cylindrical part is designed in a two-shell construction, the outer shell can be dimensioned for the absorption of pressures and tensile forces, while the inner shell, which in this case does not have to be firmly connected to the end wall parts, is dimensioned for the absorption of any detonation forces and consequently one represents inner protection for the outer shell.

Of the various parts prefabricated for assembly by the method according to the invention, the end wall parts with the fixed, cylindrical connecting pieces for the connection of the cladding sheets are thus largest separate units, while the other parts consist of cladding sheets or plates, each of which can be found, for example, over the half the circumference of the cylindrical part, but only extend over a part of its length, and from connecting yokes, intermediate pieces, screws, sealing compound and any interior equipment such as goods handling equipment. If the end wall parts are also provided with doors, for example in the form of gas-tight sliding doors, these can be delivered separately.

Abb. 1

eine Druckkammer in Schrägansicht;

Abb. 2

einen Stirnwandteil einer Druckkammer mit anderem Typ von Tür als dem in Abb. 1 dargestellten in Vorderansicht;

Abb. 3

einen Teil einer Druckkammer gemäß Abb. 2 in Draufsicht als Längsschnitt;

Abb. 4

den größten Teil eines Querschnitts durch den zylindrischen Teil einer der Druckkammern gemäß Abb. 1 oder 2;

Abb. 5

eine Kreuzung zwischen einer Quer- und einer Längsfuge auf der Innenseite einer erfindungsgemäßen Druckkammer;

Abb. 6

den Querschnitt der in Abb. 4 eingekreisten Fuge in vergrößerter Teilansicht;

Abb. 7

den Querschnitt der in Abb. 5 eingekreisten Fugenkreuzung in vergrößerter Teilansicht;

Abb. 8 und Abb. 9

die in Abb. 3 eingekreisten Einzelheiten VIII und IX in vergrößerter Teilansicht;

Abb. 10

ein Teil der Führungsschienen für die in Abb. 2 und 3 abgebildete Schiebetür in vergrößerter Teilansicht.

The invention is defined in the following claims. A more detailed description of the invention follows after a number of figures, in which:

Fig. 1

a pressure chamber in an oblique view;

Fig. 2

an end wall part of a pressure chamber with a different type of door than that shown in Fig. 1 in front view;

Fig. 3

part of a pressure chamber according to Fig. 2 in plan view as a longitudinal section;

Fig. 4

most of a cross section through the cylindrical part of one of the pressure chambers according to Fig. 1 or 2;

Fig. 5

a cross between a transverse and a longitudinal joint on the inside of a pressure chamber according to the invention;

Fig. 6

the cross section of the circled in Fig. 4 in an enlarged partial view;

Fig. 7

the cross section of the circled joint in Fig. 5 in an enlarged partial view;

Fig. 8 and Fig. 9

the details VIII and IX circled in Fig. 3 in an enlarged partial view;

Fig. 10

a part of the guide rails for the sliding door shown in Fig. 2 and 3 in an enlarged partial view.

The individual images are drawn on different scales depending on the need for individual representation.

A pressure chamber as shown in Figure 1 comprises two Factory-made end wall parts 1 and 2. The figure shows an openable door 3 for end wall part 1. Both the front wall part and the door and door frame are, as can be seen from the illustration, strongly reinforced. As the illustration also shows, the two end wall parts also each have a shorter, cylindrical connecting part 4 and 5.

In the process characterizing the invention, three cylinder sections 6, 7 and 8 lie between the end wall parts, each consisting of two bulbous sheets 6a, 6b, 7a, 7b and 8a, 8b joined together by longitudinal joints 6c, 6d, 7c, 7d and 8c, 8d , whereby in Figure 1 the c-longitudinal joints are visible and the other joints are covered. These three cylinder sections are connected to one another via the transverse joints 9 and 10 and thereby form a cylindrical part of the pressure chamber to which the end wall parts are fastened via the transverse joints 11 and 12.

In Figures 2 and 3 and 8, 9 and 10 an optional embodiment with sliding door is shown. In Figures 2 and 3, the pressure chamber has the reference number 13. At the end of one end wall part, guide rails 14 and 15 and a sliding door 16 which can be displaced in the longitudinal direction of the rail by means of a ball screw are arranged. The opening position of the sliding door is shown in Fig. 2 by the broken line 16a. To ensure a tightly fitting and sufficiently resistant sliding door, the guide rails 14 and 15, as indicated in Figure 10 and there designated 15a, are designed with a wedge-shaped taper in the front area along the pressure chamber front. The sliding door 16 rests on a lower ball bushing and is guided on the upper edge in longitudinal linear elements. In addition, the reinforcement and sealing parts shown in Fig. 8 and 9 are also available. At the front edge as seen in the closing direction, the sliding door 16, as can be seen in FIG. 8, engages with a guide groove formed by two sheets, and an inflatable sealing strip 19 also runs around the entire inside of the sliding door is hinted at in Fig. 3.

At the rear edge as seen in the closing direction, the sliding door 16 has a hook-shaped end 20 which extends over the entire part of the rear edge, which neither in the guide rails 14 and 15 nor in the closed position of the sliding door in the groove formed between the sheets 17 and 18 lies. This hook-shaped closure encompasses an extension 17a of the sheet 17 in the closed position of the sliding door, as can be seen in FIG. 9. This results in a maximally stable fastening on all edges of the sliding door along the guide rails 14 and 15, between the sheets 17 and 18 and on the hook-shaped end 20 behind the extension 17a of the sheet 17. The inflatable sealing strip 19 running around the inside of the entire sliding door ensures gas tightness.

The connection of the individual cladding sheets with each other and the cylindrical parts of the end wall parts with the cladding sheets is carried out according to identical principles, which are illustrated in Figures 4, 6 and 7 and partly also in Fig. 5.

The same division principles can also be used for dividing the end wall parts into smaller parts. For example, in the end wall part shown in FIG. 2, the joints can advantageously be arranged along the markings 39-40. In the end wall part with a sliding door, these joints primarily concern the jacket sheets of the end wall part, ie the cylindrical part of the end wall part. The guide rails 14 and 15 are then expediently designed to be removable. According to the same principles, the sliding door can also be divided into smaller parts, for example along a central joint. It is clear that this simplifies the transport of the individual parts, since, for example, certain maximum dimensions for the load are specified for trucks.

From the cross section of the pressure chamber shown in Fig. 4 it can be seen that it consists of an outer jacket 21 which is made up of two jacket plates 21a and 21b which are connected to one another via two joints or joints 22a and 22b.

Figure 6 shows the joint 22a in a partially enlarged cross section. The pressure chamber also includes an inner jacket 23 with the jacket plates 23a and 23b, which are connected to one another via two joints or joints 24a and 24b, only joint 24a being shown in the figure. Fugue 24a is also shown on a larger scale in Fig. 7.

The joints or joints 22a and 22b or 24a and 24b are longitudinal joints. With the exception of the arch-shaped instead of the straight joint parts, the transverse joints are identical to the longitudinal joints. Since the joint 24a is shown in Fig. 7 at the intersection between an inner longitudinal joint and an outer transverse joint, parts of the transverse joint are also shown in this figure.

The joint 22a shown in cross section in FIG. 6 lies between the two cladding sheets 21a and 21b. Each of the cladding plates has a fold on the joint side which is directed towards the pressure chamber and is designated 25 or 26. These two folds each have a first fold edge 25a or 26a directed towards the broad side of the respective cladding plate (i.e. in the assembled state are directed away from each other). These first fold edges form acute angles to the wide side 21a 'or 21b' of their respective cladding sheet. The folds also each have a second fold edge 25b or 26b, which in the assembled state are directed towards one another and form obtuse angles to the wide side 21a 'or 21b' of their respective casing sheet. These second fold edges coincide with the outer, mutually facing joint edges of the casing sheets. Together, the joints with the folded edges have a dovetail cross-section.

A connecting yoke 27 is attached above the two folds and has a groove 28 with a dovetail cross section and with two clamping edges 28a and 28b directed towards one another, the latter abutting against the fold edges 25a and 26a. The groove 28 has a minimum width such that the connecting yoke 27 can be guided over the folds 25 and 26 when the two jacket plates 21a and 21b are pushed together as closely as possible, after which the jacket plates are pushed apart until the first fold edges 25a and 26a against the tensioning edges 28a and 28b are present. An intermediate piece 29 with a trapezoidal cross-section and with the edge sides 29a and 29b is then arranged between the second folded edges 25b and 26b, i.e. between the outer joint edges of the cladding sheets. This intermediate piece 29 is fastened in the connecting yoke 27 with screws 30 arranged in a uniform division. By tightening the screws 30 a very tight and high-strength connection is obtained, since the intermediate piece 29 due to the wedge action between its own edge sides 29a and 29b on the one hand and between the second fold edges 25b and 26b on the other hand, the folds with high force against the clamping edges 28a and 28b Connection yoke 27 presses. The inner sheet 23a is also indicated in Figure 6.

As can be seen in the figure, the folds 25 and 26 are designed as separate parts, which only have a narrow jacket sheet edge and are welded to smooth-surface sheets with a double V-seam. This work is carried out at the factory.

Figure 7 shows the corresponding inner joint with the inner cladding sheets 23a and 23b, the folds 31 and 32 with the respective first fold edges 31a and 32a and the corresponding second fold edges 31b and 32b, the connecting yoke 33 with the clamping edges 33a and 33b and the intermediate piece 34 and the screw 35.

Since a crossing between an outer and an inner joint is shown in Fig. 7, there also appears a connecting yoke 36 for the outer joint together with its intermediate piece 37 and two Screws 38. Otherwise this applies to the joint acc. Figure 6 said the same for the joint shown in Fig. 7.

REFERENCE LIST DIRECTORY

1

Front wall part

2nd

Front wall part

3rd

door

4th

Connecting part

5

Connecting part

6

Cladding sheet

7

Cladding sheet

8th

Cladding sheet

9

Transverse joint

10th

Transverse joint

11

Transverse joint

12

Transverse joint

13

Pressure chamber

14

Guide rail

15

Guide rail

16

sliding door

17th

sheet

18th

sheet

19th

Sealing strip

20th

Graduation

21

Outer jacket

22

Gap

23

Inner jacket

24th

Gap

25th

Fold

26

Fold

27th

Connecting yoke

28

Clamping edge

29

Spacer

30th

screw

31

Fold

32

Fold

33

Clamping edge

34

Spacer

35

screw

36

Connecting yoke

37

Spacer

38

screw

39

Gap

40

Gap

Claims (10)

Process for producing a pressure chamber which is resistant to internal detonations and has a substantially cylindrical shape with end walls, characterized in that the cylindrical wall (6, 7, 8) of the pressure chamber (1, 13) consists of individual curved plates (6a, 6b, 7a, 7b , 8a, 8b) which have upstanding, undercut folds (25, 26) on their edges, and that the plates are joined together along the axial and circumferential joints in such a way that from one side a connecting yoke (27) extending along the joint in the form of a U-shaped bar with a dovetail-shaped groove, encircling the folds, and from the other side an intermediate piece (29) in the form of a wedge-shaped bar is inserted into the joint and against the connecting yoke ( 27) is clamped around the undercut rear sides (25a, 26a) of the folds (25, 26) sealing against the flanks (28a, 28b) of the to press dovetail-shaped groove. Process for the production of assemblable pressure chambers according to claim 1, characterized in that the cylindrical part of the pressure chamber is constructed in two-shell construction, the joints between the individual shells also being laterally offset from one another. A method according to claim 1 or 2, characterized in that the folded edges of the jacket sheets and the tensioning edges of the connecting yokes are designed with flanks which are inclined in relation to the jacket sheets, which together with the intermediate piece result in a dovetail-shaped wedging at the joint between jacket sheets and connecting yokes. Method according to one of claims 1, 2 or 3, characterized in that the end wall parts of the pressure chamber are connected to the jacket plates forming the cylindrical part of the chamber by jacket plate parts firmly connected to the end wall parts with transverse joints of the same type as in the connection of the individual jacket plates . Pressure chamber with resistance to internal detonations of essentially cylindrical shape with end walls, producible according to the method according to one of Claims 1 to 4, characterized in that the cylindrical wall (6, 7, 8) of the pressure chamber (1, 13) consists of bent plates (6a, 6b, 7a, 7b, 8a, 8b), which have folds (25, 26) that stand up along their edges and have undercuts on the back and each on the joints running in the axial and circumferential direction by means of a connecting yoke (27) in each Form a U-shaped strip with a dovetail-shaped groove that encompasses the two folds (25, 26) of the adjacent panels, and an intermediate piece (29) inserted into the joint, which is designed as a wedge-shaped strip and thus against the connecting yoke (27) is braced that it separates the plates and thereby seals the undercut backs (25a, 26a) of the folds sealing against the flanks (28a, 28b) of the swallow N-shaped groove of the connecting yoke presses. Pressure chamber constructed from elements according to claim 5, characterized in that the cylindrical Part of the pressure chamber is designed in a two-shell construction, the joints of the respective sheet metal shells (21, 23) also being laterally offset from one another and the connecting yokes in both shells being directed inwards towards the space between the shells. Pressure chamber constructed from elements according to claim 5 or 6, characterized in that the end wall parts (1, 2) thereof are designed with or without openable doors, with a shorter cylindrical part (4, 5) firmly connected to the end section, at least the latter outer jacket sheets are closed at their free end with the same dovetail-shaped folds as with the other jacket sheets and are joined there in a corresponding manner with the cylindrical part of the chamber. Pressure chamber constructed from elements according to claim 5, 6 or 7, characterized in that the longitudinal joints (6c, 7c, 8c) between the jacket plates comprise a connecting yoke and intermediate pieces with a length of at least one jacket plate, while the transverse joints (9, 10, 11 , 12) arcuate connecting yokes and connecting pieces with a length corresponding to the circumference of the half chamber and where the joints between them are laterally offset in relation to the longitudinal joints. Pressure chamber constructed from elements according to one of claims 5 to 8, characterized in that its end wall parts (1, 3) with the cylindrical part (6, 7, 8) constructed from jacket sheets by transverse joints (11, 12) of the same construction as in the transverse joints between the casing sheets (9, 10) are connected, this being made possible in that the respective end wall part with its own fixed, cylindrical connecting part (4 or 5) was provided, which is finished with the same type of fold as the jacket sheets. Pressure chamber constructed from elements according to one of Claims 5 to 9, characterized in that the end wall parts and cylindrical connecting parts can be divided into smaller sections by means of joints (39, 40) made in the same way as for the other parts.

Images