ARRANGEMENT FOR THE CONNECTION OF TUBES

Abstract: A mechanical connection arrangement for tubes arranged alongside or after one another comprises a coupling ring or coupling piece (5, 9) positioned at the end of the tube and surrounding the tube, a profiled rod (8) of constant cross-section facing inwards from the end of the tube (1, 2), and at least one attachment device (6, 7) arranged in the wall of the tube and at a certain distance from its end so executed as to engage with and to force the profiled rod (8) into contact with the internal surface of the tube (1, 2) at contact points along two narrow contact lines or contact areas (14, 15) running in the longitudinal sense of the tube (1, 2).

Description: ARRANGEMENT FOR THE CONNECTION OF TUBES The present invention relates to an arrangement for the mechanical connection of tubes of different cross-sectional form arranged alongside or after one another. Tube connections of various kinds are already disclosed, in which use is made of expanding internal joint devices or joint devices with clamps which are tightened with a nut and bolt. A simple and inexpensive, yet very effective connection arrangement is obtained by the arrangement in accordance with the invention. This is achieved by means of a coupling ring positioned at the end of the tube and surrounding the tube, a straight profiled rod of constant cross-section facing inwards from the end of the tube and passing through the coupling ring, and at least one attachment device arranged in the wall of the tube and at a certain distance from the end of the tube so executed as to engage with and to force the profiled rod into contact with the internal surface of the tube at contact points along two contact lines or contact areas running in the longitudinal sense of the tube. Additional advantages are achieved through the characteristic features indicated in the subsidiary Patent Claims. The invention is now described in greater detail in relation to a number of embodiments given by way of example in conjunction with the accompanying drawings, in which: Fig. 1 illustrates in perspective two side tubes in a frame structure and components for connecting the tubes; Fig. 2 illustrates a section through the frame tube in Fig. 1, but with a coupling ring for an additional tube; Fig. 3 is a view from above of the arrangement shown in Fig. 2, with the indicated section line II—II for the section in Fig. 2} Fig. 4 is a view from above, corresponding to that shown in Fig. 3, but with an adapter consisting of four interconnected coupling rings; Fig. 5 is a view from above of an adapter executed from three interconnected coupling rings; Fig. 6 illustrates a locking component for the tube and the coupling ring; Fig. 7 illustrates the locking component applied to a frame tube; Fig. 8 is a section through the frame in Fig. 7 in accordance with the line 1/III-VIII; Fig. 9 illustrates connection components with a twisted profiled rod; Fig. 10 shows a cut-away from above in accordance with the line X-X in Fig. 9; Fig. 11 illustrates components used for connection in the case of square tubes, with an eccentric as the attachment device; Fig. 12 shows the arrangement in Fig. 11 viewed from above; Fig. 13 illustrates a frame produced by means of the invention for supporting one or more shelves; Fig. 14 shows eight frame tubes, included in four frames, attached to one another and provided with feet; Fig. 15 shows a wall consisting of six frames with twelve interconnected frame tubes set up on an uneven floor; Fig. 16 shows the lower part of the frames in Fig. 15; Fig. 17 shows the upper part of the frames in Fig. 15. The designation 1 is used in Fig. 1 in respect of a frame tube which is a constituent part of a frame, whereas 2 is used to designate the corresponding frame tube in a superjacent frame. 3 is one of the side tubes in the frame 1, and 4 is one of the side tubes in the frame 2. The designation 5 is used in respect of. a simple coupling ring which is so executed as to be capable of accommodating on its .inside the tubes 1 and 2, respectively on the lower side and on the upper side. The design of the ring is described in greater detail below. Internally threaded blind rivets 6 are securely attached to the walls of the tubes 1 and 2 close to the ends of the tubes. Screws 7 with hexagonal socket heads are threaded into the rivets 6. These screws serve as attachment devices for the profiled rod 8. When screwed in fully, the screws force the profiled rod 8 hard up against the inside of the tube walls so that longitudinal narrow contact lines or contact areas with contact points are formed. These exhibit considerable resistance to the displacement of the profiled rod in its longitudinal sense. Fig. 2 shows a section through a connection in the installed position, where two frame tubes 1 and 2 have been pushed in towards the coupling ring 9, which is a double coupling ring with two transcurrent openings 10 and 11 which at their central part have a supporting flange 12 against which the ends of the two tubes 1 and 2 can rest. A clearance 13 is present between the tube and the ring. The components described above and the contact lines 14 and 15 at the ends of the profiled rod 8 can be appreciated from Fig. 3. The fact that the contact lines 14 and 15 are situated at a certain distance from one another means that the tube connection is very rigid in the longitudinal sense of the cross-section of the profiled rod. Because the two tubes are in contact with the supporting flange 12 and are prevented from sliding apart by the attachment devices 6, 7 inside the tubes 1 and 2 and the profiled rod 8, the tube connection is also very rigid in the transverse sense of the cross-section of the profiled rod.- This means that the tube connection is rigid in all directions. The foregoing also means that the double coupling ring 9 is so firmly attached to the tubes 1 and 2 that it is capable of supporting a tube 16 in the manner indicated with broken lines in Fig. 2. A frame attached to the tube 1 is able to form any desired angle with the frame of which the tubes 1, 2 are a part. If it is wished for the assembled frames to be capable of being pivoted relative to one another, it is possible when assembling the tube connection to leave a small clearance between the ends of the tubes 1 and 2 and the supporting flange 12 of the coupling ring. Fig. 4 illustrates a quadruple coupling 17 for the connection of up to eight lengths of tube. In the top right-hand opening of the coupling the profiled rod is in the form of a U-shaped profile, whereas in the bottom right-hand opening the profile rod has an I-shaped section. The two profiles are designated by IB and 19. The greater rigidity of the profiled rods 18 and 19 permits the contact pressure to be increased, enabling the connection to absorb higher forces. The arrangement shown in Fig. 4 with frames situated at a certain distance from one another can be used, for example, for the construction of partition walls in offices, etc., by securing panels 20 and 21 to the external surfaces of the frames. In the event of thermal or acoustical insulation being required, it is possible to install material 22 suitable for the purpose between the panels 20, 21. Fig. 5 illustrates in the form of a sketch a coupling ring containing openings and flanges for up to three tubes to either side of the coupling ring. Fig. 6 shows a locking component 23, which exhibits a head 24 and a profiled shaft 25 which may have any of the previously described cross-sections. The diameter of the head, which in the example shown here is adapted for a circular tube, is of approximately the same size as the external diameter of the tube. Fig. 7 shows the locking component installed in the upper end of a frame tube 1 as a partially sectioned perspective view. The designations are those previously used. Fig. 8 is 8 section through the tubular frame component shown in Fig. 7 and illustrates the function of the locking component. Application of the screw 7 causes the profiled shaft 25 to be forced against the internal wall of the tube 1 in the same way as described for the profiled rod 8. At the same time the head 24 of the locking component 23 is acted upon in such a way that it is tilted and is forced against the supporting flange 12 with one edge 26 of the head, thereby locking the double coupling ring 9 securely to the end 1 of the tube. Any desired number of tubes can be locked in a similar fashion in a secure connection. Fig. 9 illustrates an embodiment with a profiled rod 27 which has been twisted about its straight central line 28. This embodiment makes .it possible to connect together two frame tubes which are lying one after the other, with a desired angular twist. Fig. 10 shows the components in Fig. 9 viewed from above. The manner in which the frames have been pivoted through an angle 28 in relation to one another can be appreciated from the Figure. This angle can be selected between ' 0° and 90°, which in turn makes it possible to select the angle between the frames within the range 0°-360°. The profiled rod 27 is thus twisted to the angle which it is wished for the frames to form. By selecting the length of the cross-section of the profiled bar 27 so that it is only slightly smaller than the internal diameter of the tube, it is possible to produce an effect for centering the tubes 1 and 2. Fig. 11 illustrates a further example of the invention applied to the connection of square tubes, for which the designation 29 is used. The attachment device in this case consists of an eccentric disc 30 which is capable of being turned until it is forced against the profiled rod 8 by means of a handle 32 on a pivot shaft 31. A simple coupling ring 5 of previously described execution is used to guide the tube ends. The ring thus rests against the four corners of the square tube. Fig. 12 illustrates how the profiled rod 8 is forced against the inside of the tube in order to produce contact lines 14 and 15. fig. 13 shows a tubular frame with feet 34 with foot plates 35 and a foot shaft 36. The foot shaft has a transverse section which may be executed in one of the ways previously described. The bottom ends 38 and 39 of the frame tubes have attachment devices 6 and 7 of a previously described design which lock the feet 34 to the frame, which can thus be positioned vertically. A shelf 37 for books or other articles has been hung on the frame shown here. It is, of course, possible to attach other devices to the frame. Fig. 14 shows two frame structures arranged at an angle in relation to one another and connected by means of single coupling rings 5 and double coupling rings 9. It is obvious that any desired number of frames can be assembled one after the other, and that structures can be built with three or more frames, which are brought together at a single point with the help of coupling rings with three or more openings, as shown in Figs. 3-5 above. Fig. 15 shows two frame structures, each consisting of three frames fixed one above the other. The frame structures are connected to one another by means of double coupling rings 9, which are capable of pivoting relative to the frame tubes. This makes it possible for the tubes to adopt positions such that they are not entirely parallel to one another. This can be appreciated in more detail from Fig. 16, which shows the position of the upper coupling ring, and from Fig. 17, which shows the position of the lower coupling ring. As will be appreciated from both Figures, a line passing through the centre of the openings of the double ring 9 forms an acute angle with the plane of the tubular frames at the top, and an acute angle in the opposite direction towards the plane of the tubular frames at the very bottom. By connecting the frames together in this way it is possible to compensate for an uneven floor, where this is desirable when connecting together a number of frames. A person skilled in the art is capable of designing structures additional to those illustrated above by way of example and described within the scope of the accompanying Patent Claims.

Claims: Pa tent Claims 1. Arrangement for the mechanical connection of tubes arrβnged alongside or after one another, characterized by — a coupling ring or coupling piece (9, 5) positioned at the end of the tube and surrounding the tube; — a profiled rod component (8, 18, 19) of constant cross-section facing inwards from the end of the tube; and — at least one attachment device (6, 7; 30, 31) arranged in the wall of the tube and at a certain distance from the end of the tube (1, 2, 29) so executed as to engage with and to force the profiled rod (8, 18, 19) into contact with the internal surface of the tube (1, 2, 29) at contact points along two narrow contact lines or contact βreas (14, 15) running in the longitudinal sense of the tube. 2. Arrangement according to Claim 1, characterized in that the attachment device consists of a screw (7) interacting with a threaded bush (6) arranged in the tube (1, 2). 3. Arrangement according to Claim 1, charac terized in that the attachment device consists of a rotatable eccentric arrangement (30, 31, 32). 4. Arrangement according to Claim 1, characterized in that the profiled rod exhibits a square cros9-section (8) with a surface perpendicular to the attachment device (6, 7; 30, 31, 32). 5. Arrangement according to Claim 1, characterized in that the cross-section of the profiled rod (18, 19) exhibits one part which is perpendicular to the attachment device (6, 7) and two lateral parts at an angle thereto, for example of I—, U— or VA-form. 6. Arrangement according to Claim 1, characterized in that the coupling ring (9, 17, 40) is executed with two or more openings (10, 11) arranged coaxially with the tube. 7. Arrangement according to Claims 1 or 6, character¬ i z e d in that the coupling ring on the inner surface of the coupling has an inward executed supporting flange (12) so arranged as to make contact with the end (1, 2) of the tube. 8. Arrangement according to Claim 1, characterized in that the profiled rod (25) is securely attached to a transverse plate (24) arranged at its end, which plate is so arranged as to push against the supporting flange (12) of the coupling ring (9) for the purpose of locking the coupling ring (9) and the tube (1) to one another. 9. Arrangement according to Claim 1, characterized in that the profiled rod (27) is twisted through a certain angle (28) about its longitudinal axis (28) in order to permit two consecutive tubes (1, 2) to be joined with a twist relative to one another. 10. Arrangement according to Claim 1, characterized in that the profiled rod (36) is attached to a supporting foot (34) in order to permit a tubular frame (41, 42) attached to the tube to be set up on a floor.

Inventors: LUNDGREN ALVAR, LUNDGREN ANDERS, LUNDGREN, ALVAR, LUNDGREN, ANDERS
Applicants: LUNDGREN ALVAR, LUNDGREN ANDERS, LUNDGREN, ALVAR, LUNDGREN, ANDERS
Application year: 1988
Main classification: F16B7
IPC codes: A47B91, E04G7, F16B7