Abstract:
A combination of two bodies having tube-shaped or sleeve-shaped connecting sections which can be plugged into one another as part of an air-conditioning line system in an aircraft, the combination including at least one radial locking projection on a first body, at least one locking clearance on a second body which is completely surrounded by a rim, at least one lead-in clearance which is angularly offset in the peripheral direction in relation to the appertaining locking clearance, and at least one releasing groove associated with each locking clearance and disposed angularly offset in the peripheral direction on the opposite side of the appertaining lead-in clearance.

Description:
This application claims the benefit of International Application No. PCT/EP2006/008981, filed on Sep. 14, 2006, and German Application No. 10 2005 049082.4 filed on Oct. 13, 2005. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a combination of two bodies having tube-shaped or sleeve-shaped connecting sections which can be plugged into one another, as part of an air-conditioning line system in an aircraft. 
     When assembling the air-conditioning line system of an aircraft, a simple solution for connecting to one another, in a secure manner, adjoining elements of the line system that can be plugged into one another, is aspired to because of the length of the line system and the large number of connecting points which goes along with this. It is known practice to connect two line elements that have been pushed into one another, by means of an externally fitted clamp strap. The fitting of the clamp strap, and also its removal in the course of disassembly, is a comparatively laborious operation for the assembly personnel. The clamp strap also means additional material costs. 
     U.S. Pat. No. 1,033,187 discloses to couple two hose-like or pipe-like bodies by means of a locking projection which runs, when the two bodies are joined together, within a lead-in groove in the other body and finally snaps into a locking clearance constructed at the end of the lead-in clearance. In the plug-in coupling known from this document, said lead-in clearance has a number of bends, that is to say, consists of successive sections of the groove which extend alternately axially and in the peripheral direction. 
     FR 2,357,809, U.S. Pat. No. 4,758,023 WO 96/14096, and U.S. Patent Application Publication No. 2003/233,718 all disclose coupling mechanisms for coupling two tubular bodies. The bodies have end portions that can be axially inserted into each other and subsequently rotated relative to each other to join the two bodies. Relative rotation of the bodies causes a locking projection on one of the bodies to engage in a locking recess of the other body. To release the coupling of the bodies, relative rotation of the bodies in the opposite direction is required whereupon the bodies can be axially pulled apart. GB 280,556, discloses a pair of tubes or pipes each having a cross section conforming to an Archimedes&#39; spiral. To join the tubes together, the tubes are inserted into each other and then turned with respect to each other. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to show a way in which two bodies, which constitute part of an air-conditioning line system in an aircraft and possess tube-shaped or sleeve-shaped connecting sections that can be plugged into one another, can be connected to and disconnected from each other with little effort and outlay on material without compromising on the security of the connection. 
     To achieve the above object, the present invention provides a combination of two bodies having tube-shaped or sleeve-shaped connecting sections which can be plugged into one another, as part of an air-conditioning line system in an aircraft; wherein a first of the bodies carries, in its connecting section, at least one radial locking projection and the other, second body has, in its connecting section, at least one locking clearance which is completely surrounded by a rim; wherein the at least one locking projection and the at least one locking clearance are constructed, and coordinated with one another, in such a way that, in a relative locking rotational position of the two bodies, each locking projection engages in an associated locking clearance, while securing the two bodies against axial withdrawal from one another; wherein the second body has in its connecting section, in association with each locking clearance, at least one axially extending lead-in clearance which is provided so as to be angularly offset in the peripheral direction in relation to the appertaining locking clearance and which has no rim in the direction of the leading plug-in end of the second body and reaches axially, at least substantially, as far as the appertaining locking clearance, in such a way that, in a relative lead-in rotational position of the two bodies in which each locking projection lies, in the peripheral direction, in a manner overlapping with an associated lead-in clearance, easy-action axial insertion of the two bodies in one another as far as a position preparatory to locking is made possible; and wherein each locking projection has a peripheral, oblique run-up face which becomes operative when relative twisting of the two bodies out of the position preparatory to locking and in the direction of the locking rotational position occurs. 
     The invention allows secure connection of the two bodies with few manipulations and without additional connecting parts. For that purpose, said two bodies are plugged into one another with their connecting sections in a relative lead-in rotational position. When they are plugged into one another in this way, each locking projection on the first body moves axially within an associated lead-in clearance in the second body. The connecting sections of the two bodies are expediently configured in such a way that, in other relative rotational positions in which the locking projection or projections on the first body are angularly offset in relation to the lead-in clearance or clearances in the second body, it is either impossible to push them into one another axially or else this is possible only at the risk of damaging the bodies. In the lead-in rotational position, on the other hand, this pushing of said bodies into one another is possible in an easy action, particularly since the axial relative movement of the bodies is not hindered by a rim on that end of each lead-in clearance which is the leading end in the direction of plugging-in. Here, the terms “axial” and “radial” refer to the axis of the tube-shaped or sleeve-shaped connecting sections. 
     If the connecting sections of the two bodies are pushed into one another axially into a position preparatory to locking, they can then be transferred into a locking rotational position by relative twisting. In the process, each locking projection passes out of its lead-in clearance and moves along, under the wall of the connection section of the second body, until it passes into an associated locking clearance. The passing of the locking projection out of the lead-in clearance is facilitated, or even made possible at all, by the peripheral, oblique run-up face formed on the locking projection. At its axial side which is the trailing side in the direction of plugging-in, the locking projection is advantageously configured so as to be sufficiently steep, in the event of an attempt to withdraw the bodies from one another axially in the locking rotational position, to effectively counteract the attempted pulling-apart of said bodies by impinging against the rim of the locking clearance. 
     The second body also has in its connecting section, in association with each locking clearance, a releasing clearance which is provided in a manner angularly offset in the peripheral direction in relation to the appertaining locking clearance and is disposed in the opposite direction to the appertaining lead-in clearance and which likewise has no rim in the direction of the leading plug-in end of the second body and reaches axially, at least substantially, as far as the appertaining locking clearance, in such a way that, in a relative releasing rotational position of the two bodies in which each locking projection lies, in the peripheral direction, in a manner overlapping with an associated releasing clearance, easy-action axial pulling-apart of the two bodies, starting from a position preparatory to release, is made possible, and the two bodies can be transferred, with the peripheral, oblique run-up face becoming operative, out of the locking rotational position by relative twisting into the position preparatory to release. 
     Through the provision of the releasing clearance it is possible, by renewed twisting of the two bodies in the same direction of relative rotation in which they were transferred out of the position preparatory to locking and into the locking rotational position, to achieve a position preparatory to release from which the bodies can be released from one another by easy-action axial withdrawal. In the course of such axial withdrawal, each locking projection moves within an associated releasing clearance in the second body. The two bodies can thus be connected to one another by pushing them into one another axially and then twisting them, and can be released from one another again by turning them further in the same direction of rotation and subsequently pulling them apart axially. In the process, the peripheral, oblique run-up face facilitates, or makes possible, the passage of the locking projection out of the particular locking clearance. A single peripheral, oblique run-up face on each locking projection is therefore sufficient. 
     It may be that each locking clearance and/or each lead-in clearance and/or each releasing clearance passes right through the wall of the connecting section of the second body. However, it is also possible for each locking clearance and/or each lead-in clearance and/or each releasing clearance to pass, at least in certain regions, through the wall of the connecting section of the second body only over part of the thickness of said wall. 
     The first body is preferably designed with a total of two diametrically opposed locking projections, while the second body is likewise designed with a total of two diametrically opposed locking clearances. However, it is possible to provide more than two locking projections and more than two locking clearances. 
     At least one of the two bodies is preferably a line pipe of the air-conditioning line system, in particular an air line pipe. If it should be necessary to temporarily or permanently close a line pipe of this kind, the other body may constitute, for example, a sealing cap which is to be placed on said pipe. If a number of line pipes are to be connected in series, one of the bodies may be one of these pipes and the other body may be a coupling piece which is to be inserted between this first pipe and another pipe. In this case, the coupling piece may have a flexible, bellows-type section which is adjoined, on each of its two sides, by a stiff connecting section. In this way, it is possible to couple two pipes to one another in a non-rigid manner. Naturally, use may also be made of a coupling piece which is rigid as a whole, instead of one having a soft, bellows-type section in the middle. It is also conceivable for one of the bodies to be a flexible line hose whose connecting section, however, is manufactured from a stiff material. No special mention needs to be made of the fact that the aforesaid examples of application are not exhaustive and that the invention is not in any way restricted thereto. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained further below with the aid of the appended drawings, in which: 
         FIG. 1  represents, in an axial longitudinal section, a first exemplified embodiment of a combination according to the invention; 
         FIG. 2  represents a plan view of a pipe as a first body of the combination in  FIG. 1 ; 
         FIG. 3  represents an axial cross-section through a sealing cap as a second body of the combination in  FIG. 1 ; 
         FIG. 4  represents an axial longitudinal section through the sealing cap in  FIG. 3 ; 
         FIG. 5  represents an axial longitudinal section through a combination according to a second exemplified embodiment of the invention; and 
         FIG. 6  represents an axial longitudinal section through a combination according to a third exemplified embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1 , the combination shown therein consists of a line pipe  10  and a sealing cap  14  which is placed on an end section  12  of said pipe  10 . Said sealing cap  14  has approximately the shape of a pot, its casing, which is designated by  16 , forming a tube-shaped or sleeve-shaped connecting section within the meaning of the invention. The end section  12  of the pipe  10  forms another tube-shaped or sleeve-shaped connecting section within the meaning of the invention. At its outer periphery, the end section  12  of the pipe is designed with two diametrically opposed, radially protruding locking projections  18 , as can also be seen in  FIG. 2 . Constructed on each of the locking projections  18  is a peripheral, oblique run-up face  20  which, observed in axial cross-section, extends obliquely in relation to the peripheral direction. The peripheral, oblique run-up faces  20  on the two locking projections  18  are oriented in the same direction. Additionally, the locking projections  18  each include a face  21  opposing the peripheral, oblique run-up face and extending in a generally perpendicular direction from the end section  12  of the pipe  10 , as shown in  FIG. 2 . 
       FIGS. 3 and 4  show that there are moulded into the casing  16  of the sealing cap  14  two locking clearances (locking recesses)  22  which are diametrically opposed to one another and pass right through said cap casing  16  over its entire thickness. In addition, a lead-in clearance (groove)  24  and a releasing clearance (groove)  26  are formed into the cap casing  16  on either side of each locking clearance  22  in the peripheral direction in each case. In the exemplified case shown, the lead-in and releasing clearances  24 ,  26  do not go through the entire thickness of the cap casing  16  of the sealing cap  14 . In a modified form of embodiment, they can, of course, go right through the entire thickness of the cap casing  16 . 
     The locking clearances  22  are completely surrounded by a rim. The lead-in and releasing clearances  24 ,  26 , on the other hand, are continuous as far as that plug-in end of the cap casing  16  which is the leading end when the sealing cap  14  is slipped onto the pipe  10 , and therefore have no rim towards this leading end of the casing. The locking clearances  22  are provided at an axial distance from the leading end of the casing and possess an axial extent which is substantially equal to the axial extent of the locking projections  18 . The lead-in and releasing clearances  24 ,  26  extend axially substantially as far as the locking clearances  22  and permit comparatively easy-action sliding of the locking projections  18  within the clearances  24 ,  26 . 
     In order to place the sealing cap  14  on the pipe  10 , said cap  14  is put onto said pipe  10  in a relative rotational position such that the lead-in clearances  24  lie, in the peripheral direction, in a manner overlapping with the locking projections  18  on the pipe  10 . In this lead-in rotational position, the sealing cap  14  is pushed axially onto the end section  12  of the pipe, or said end section is pushed axially into the cap  14 . In order to facilitate the pushing of the cap  14  and pipe  10  into one another, the locking projections  18  may likewise be bevelled on their axial side which is the leading side in the direction of plugging-in, although this is not represented in that way in  FIG. 1 . If the clearances  24 ,  26  are designed as slots which pass right through the cap casing  16 , it is possible to dispense with an axial obliquity of this kind on the locking projections  18 . 
     The cap  14  is pushed onto the pipe  10  until the locking projections  18  lie substantially at the same axial level as the locking clearances  22 . This position, which may be described as the “position preparatory to locking”, may, for example, be defined by the striking of the locking projections  18  against the rear boundary edges of the lead-in clearances  24 . It is also conceivable for the position preparatory to locking to be defined by the striking of the front end of the pipe against the bottom of the sealing cap  14 . In any case, it is possible, by relative twisting of the sealing cap  14  and pipe  10  in a first direction starting from the position preparatory to locking, to achieve a locking rotational position in which the locking projections  18  engage in a locking manner in the locking clearances  22 . This condition is shown in  FIG. 1 . In the course of this twisting operation in the first direction, the peripheral, oblique run-up faces  20  on the locking projections  18  facilitate or permit the possibility of said locking projections  18  being pushed under the wall of the cap casing  16 . The faces  21  on the locking projections  18  prevent relative twisting of the sealing cap  14  and pipe  10  in a second direction opposite the first direction. 
     In order to then release the sealing cap  14  from the pipe  10  again, said sealing cap  14  is turned further, relative to the pipe  10 , in the same direction of rotation as before in the case of the locking operation, under which circumstances the locking projections  18  pass out of engagement with the locking clearances  22 . The sealing cap  14  is turned, relative to the pipe  10 , until the locking projections  18  penetrate into the releasing clearances  26 . The passing of the locking projections  18  out of the locking clearances  22  is, once again, facilitated or made possible by the peripheral, oblique run-up face  20  on said locking projections  18 . As soon as the locking projections  18  have reached the releasing clearances  26 , the sealing cap  14  can be withdrawn axially from the pipe  10 . 
     In the exemplified case in  FIG. 1 , the axial end face of the pipe  10  is bevelled slightly, from radially inside to radially outside, in the direction away from the end of the pipe. For its part, the sealing cap  14  is designed with an oblique face having the same direction in the transitional region between the bottom of the cap and the casing  16  of the latter. The location of the locking projections  18  and locking clearances  22  may be selected in such a way that, in the locking rotational position shown in  FIG. 1 , the bevelled end face of the pipe  10  bears in a laminar manner against the opposed oblique face of the sealing cap  14  and thus ensures a leakproof connection between said pipe  10  and said sealing cap  14 . 
     In  FIGS. 5 and 6 , components which are the same or act in the same way are designated by the same reference numerals as in  FIGS. 1 to 4 , but with the addition of a small letter. 
       FIG. 5  shows an exemplified embodiment in which two pipes  10   a  are coupled to one another by a coupling piece  28   a . Said coupling piece  28   a  has two sleeve-shaped connecting sections  30   a  which are manufactured from a stiff material and have, in each case, two diametrically opposed locking clearances  22   a . Between the connecting sections  30   a , the coupling piece  28   a  has a flexible bellows-type section  32   a  made of a comparatively soft material. Said bellows-type section  32   a  allows changes in location of the pipes  10   a  relative to one another without, in the process, impairing the fixed connection between the coupling piece  28   a  and each of the pipes  10   a.    
       FIG. 6  shows an exemplified embodiment in which a pipe  10   b  is connected to a hose  34   b . Said hose  34   b  is, in itself, of flexible design, but has a stiff connecting section  36   b  at one of its ends. Constructed in the connecting section  36   b  are two diametrically opposed locking clearances  22   b , in each of which a locking projection  18   b  on the pipe  10   b  engages when in the locked condition. 
     Naturally, the coupling piece  28   a  and also the hose  34   b  in the exemplified embodiments in  FIGS. 5 and 6  are also provided with lead-in clearances and releasing clearances, although these clearance are not shown in the figures.