AU3617484A

AU3617484A - Joint unit for hollow profiles

Info

Publication number: AU3617484A
Application number: AU36174/84A
Authority: AU
Inventors: G.O. Rasmussen
Original assignee: RASMUSSEN GOV
Current assignee: RASMUSSEN GOV
Priority date: 1983-11-15
Filing date: 1984-11-15
Publication date: 1985-06-03
Also published as: WO1985002234A1; EP0165259A1; DK537183D0

Description

Joint -mit for hollow profiles.

The invention concerns a joint unit for hollow profiles, e.g. aluminium profiles, which joint unit has a body ele¬ ment with legs projecting from this and the legs fitting into the hollowness of the profiles.

Square or rectangular hollow profiles of aluminium are widely used for building up frames for any purpose such as racks, tables, showcases, aquaria owing to the spe¬ cial properties of aluminium, e.g. a pleasant surface needing no maintenance. Its field of application falls as well under industry, institutions, private hospitals and exhibitions as private homes.

There exists a single joint unit which is widely applied for aluminium profiles and it is of cast aluminium and coated with a thin membrane of black plastic. The plastic membrane is meant to absorb the manufacturing tolerances which the profiles may have.. Another thing is the very appearance as the surface of a cast workpiece of alumini¬ um looks different from that of an extruded workpiece. This fact together with the problems as to the tolerances has led to the choice of a compromise solution, viz. a coating of black plastic.

The purpose of the invention is to indicate a joint unit which makes it possible to obtain that the element has the same appearance as the profiles to be joined and at the same time is cheaper than the well-known joint unit.

According to the invention this is obtained by making the joint unit of extruded hollow profiles as slices cut trans¬ versely to the longitudinal direction of the profile, and where the cross section of the profile forms the cross section of the unit through its legs and the unit is cut in a thickness corresponding to the length of the edge of width of the clear inside the profiles to be joined. By manufacturing the joint elements from extruded hollow profiles you will obtain that the elements ' surfaces will have the same appearance as the hollow profiles to be joined by them. By making the elements from extruded hol- low profiles you will obtain in addition quite different construction possibilities than by casting such as it will appear from the following.

To obtain a spacious joint element it is designed so that in the body element there is a width in the clear into which an inner tube with a square or rectangular cross section can be inserted, forming legs for the hollow pro¬ files to be joined at right angles to the other legs of the element. It is obvious that the inner tube may be shaped so that it protrudes from both ends of the ele- ment's body part or just from one of them.

It is obvious that the joint unit including the inner tube can be given various shapes in order to obtain that they are holding thehollow profiles to be joined more firmly. By way of example the side walls can be made with various toothings or another rough surface and likewise - they can be made with a bulge. The joint unit can also be designed with at least one spring element placed be¬ tween the sides of the legs meant to affect the sides with an outwards directed power. A more specific design is characterized by the end-wall of the legs having a split, tubular part in which an elastic element, e.g. a rubber or the like, is embedded. The spring power which instead of an elastic material also may be a mechanical spring thrusts the joint unit's and also the inner tube's side walls against the inner sides of the hollow profiles and by this joining them.

Another version is indicated in claim 5 and it is charac¬ terized by one end of the legs, preferably the end facing the body part, being provided with two slots placed towards each other and reaching to the edges of the legs and in which a sheet-shaped spring element is embedded by means of a bent gripping flap. The spring element is preferably of spring steel andcovers at least approximately the leg in its entire length. Besides the holding ability of the side flats of the joint unit's legs including that of the inner tube an additional strength is obtained by the sheet-shaped spring elements. In case of square hollow pro files it is consequently held on against all the four sides. The sheet-shaped spring element can be proper strip of sheet or U-shaped clamps which are placed across the legs of the joint unit. An additional ability of holding on can be obtained by a version as indicated in claim 6, characterized by the fact that in the sheet-shaped spring element there is carried out at least one forming in or- der to produce a biting tag the end of which protudes from the spring element and which is meant to mesh the hollow profile which is put down over the leg. Here the biting tag prevents the hollow profiles from being pulled out. A constructing version relating to this is indicated in , claim 7 and it is particular by the slot into which the sheet-shaped spring element is inserted being formed by two tags on the inner side of the legs facing each other and at least one tag, preferably two, at right angles to the body element and adapted so that the spring element with its gripping tag just can sit between the side faces of they^legs and the end of the tag of the body element. It can be difficult to make a slot where the legs pass into the body element; however, this has been remedied by the design indicated by which the tags can be placed relatively far from each other.

Another version where the body element can be made of aluminium as an independent part and the legs of spring steel is indicated in claim 8 and it is particular by the fact that it comprises a separate body element with at least two from each other turning holding tags with a flange which is nearly parallel to the side wall of the body element, and where the legs are two U-shaped pieces x/ two tags on the preferably of spring steel and joined so that they form a closed box as the ends of the legs -of the one part are bent towards each other and fit into cutouts at the sides of the legs of the other part, and under the cutouts the ends of the legs of this part are also bent towards each other so that can be pushed sidewards under the holding tags of the body element, and by the fact that at the overside of the one part there is made a cutout and cor¬ respondingly a pressed-out tag at the other part which fits the cutout and by this the two elements are locked together. By this design a great holding ability is a- chieved as the legs through and through are of spring steel. The special design makes the joint element a rigid unit once the legs are inserted into the hollow profiles .

To close the holes of the body element special plugs can be made to match the outer surfaces of the body element and so that they have a part fitting into the hollowness of the body element. The plugs may be separate elements or form part of the inner tubes. A special design is in- dicated in claim 10 which is characteristic by the. plug being equipped with barbs to engage barbs at an inner tube or at another plug element.

Claim 11 indicates another embodiment of the invention which is characteristic by the body element being entire- ly or partly filled with a thread-firm material, e.g. compressed steel and by the body element having tapped holes for fastening the legs with threaded pins. Thus first the legs are screwed on to the body element. This is possible when both the body element and the leg are e- quipped with tapped holes for a threaded pin, but it is suitable to use a bolt which is put through a bore at the leg and screwed up to the body element.

The design is especially suitable for joining hollow pro¬ files with a circular cross section, e.g. brass tubes. The body element can be finished with rounded corners so that the final result will have an aesthetically pleasant appearance. The rounded edges and corners make the body element match the tubes.

The plugs or cover plates closing the uncovered aper- tures of the body elements may be provided with vari¬ ous information and ornaments.^"'By way of example they may be provided with a factory mark and/or a trade mark, e.g. by stamping. The markings can also be of a more informative character. Furthermore the plugs or cover plates may have various colours which may be quite in¬ formative or quite ornamental.

Further details concerning the invention will appear from the following description in connection with the corresponding figures.

The figures show:

Fig. l a first form of embodiment of the joint unit according to the invention, viz. with two legs;

Fig. 2 like Fig. 1 but with three legs and without an inner tube and body element;

Fig. 3 like Fig. 2 but on a larger scale and shown with the ends of the hollow profiles placed on the legs of the element;

Fig. ⁴,5 show schematically how a rack is built-up by means of the joint unit of the invention;

Fig. 6 an angle joint with inner tube and joint u- nit with two legs;

Fig. 7 like Fig. 6, however, the joint unit has three legs;

.OMPI Fig. 8 a cross section of a hollow profile and an inner tube;

Fig. 9 a cross section of one of the hollow pro¬ files to be joined;

Fig. 10 a cross section of a hollow profile to be joined with a supporting flap for a shelf;

Fig. 11 a cross section of the leg of a joint u- nit provided with a toothing;

Fig. 12 a cross section of an inner tube provided with a toothing;

Fig. 13 a cross section of the leg of a joint u- nit where the leg has a bulge;

Fig. 14 a rectangular joint unit with a square ^'leg;

Fig- 15 a cross section of another embodiment of the joint unit of the invention;

Fig. 16 a cross section of the embodiment in Fig. 15, but this one equipped with inner tube and plug;

Fig. 17 like Fig. 16, but of another execution;

Fig. 18 combined inner tube and plug element, seen from above, from the side and from the end;

Fig. 19 another type of inner tube seen from above;

Fig. 20 an inner tube with a loose plug element, seen from above; Fig. 21 a plug element for the closing of the joint unit's body seen from both sides;

Fig. 22 a fitting piece seen from the front, from the side and a cross section, respectively;

Fig. 23 an inner tube meant to be combined with a plug element;

Fig. 24 an inner tube seen from above and from the side;

Fig. 25 an angle joint with the inner tube in Fig. 20 and the plug to the left in Fig. 21;

Fig. 26 a cross section of a body element closed at both sides with a plug element;^' -

Fig.' 27 perspective illustrations of a three-άimen- and 28 sional joint of three legs;

Fig. 29 same as Fig. 27 and 28, but carried out by and 30 means of a fitting piece like that in Fig. 22;

Fig. 31 a perspective illustration of a three-dimen¬ sional joint;

Fig. 32 a cross section of one more form of embodi¬ ment of the joint unit according to the in¬ vention;

Fig. 33 a cross section of a combined inner tube and plug element made to the same design as that in Fig. 32;

Fig. 34 a cross section of a combined inner tube and and plug made according to one more design

-SURE β-

and intended for hollow profiles with a par¬ tition as indicated in Fig. 35; Fig. 34 also shows it from the side;

Fig. 35 a hollow profile with a partition, seen from the end and partially as cross section;

Fig. 36 a cross section of an angle joint which is not rectangular;

Fig. 37 a cross section of a profile intended for being joined with the angle joint in Fig. 36;

Fig. 38 one more form of embodiment of the joint u- nit according to the invention and indicated by a dotted line within the assembled hollow profiles and seen from one and the opposite -side respectively;

Fig. 39 a joint according to the form of embodiment indicated in Fig. 38;

Fig. 40 a cross section of one additional form of em¬ bodiment according to the invention;

Fig. 41 a leg for the joint unit illustrated in Fig.

40 and seen perspectively;

Fig. 42, parts for the leg in Fig. 41; 43

Fig. 44 the part shown in Fig. 42 seen from both sides and from one end respectively;

Fig. 45 the part in Fig. 43 shown as in Fig. 44;

Fig. 46 a cross section of a joint unit with combined plug elementand inner tube but without the leg in Fig. 41 in place; Fig. 47 a cross section of an additional form of embodiment of the joint unit according to the invention;

Fig. 48 a spring element from Fig. 47 seen from abov from the side and from the end respectively;

Fig. 49 a jointing with a joint element as the one shown in Fig. 47 and seen directly from the end of a hollow profile;

Fig. 50 another design of the spring element con- eπplated directly from above, from the side and from the end;

Fig. 51 one more execution of the spring element con templated from above and from the end; ^"

Fig. 52 one more execution of the spring element con templated from the side, from above and from the end;

Fig. 53 one more execution form of the spring ele¬ ment seen directly from the side;

Fig. 54 a cross section of a variant of the joint u- nit shown in Fig. 47.

Fig. 55 a cross section of one more variant of the joint unit shown in Fig. 47;

Fig. 56 combined plug element and inner tube to the same design as shown in Fig. 47 and seen from the side, from above and from the end respec¬ tively;

Fig. 57 an inner tube seen directly from the side and from above, made to the same design as in Fig

Fig. 58 a form of embodiment of a plug seen from above;

Fig. 59 a sectional view of a leg from the joint unit in Fig. 54 which is provided with the spring element shown in Fig. 50;

Fig. 60 like Fig. 59, however, the spring element is made differently;

Fig. 61 like Fig. 59, but still another execution of the spring element;

Fig. 62 a variant of the joint unit shown in Fig.

47 where only one leg is drawn in detail and

Fig. 63 one more variant -of the joint unit shown in Fig. 47;

Fig. 64 shows a sectional view of a body element made to a 'design where the element is filled with a thread-firm material;

Fig. 65 like Fig. 64, but having an insert which is executed with a cover plate;

Fig. 66 show different jointings applying the body elements in Fig. 64,65;

Fig. 73 each shows a sectional view of three dif- ferent forms of embodiment of the legs for the body elements of Fig. 64 and 65, and to the left the legs are viewed di¬ rectly from the end turning away from the body element;

5U £A Fig. 76 shows a joint unit in the form of an L- piec.e made to the designs in the Figures 64 to 75;

Fig. 77 shows a joint unit intended for hollow pro- files with circular cross sections;

Fig. 78 show sectional views of two different a r,r* 7Q cover plates for the joint unit in Fig. 77.

Fig. 1 shows a joint unit 1 according to the invention mad _.from an extruded, hollow aluminium profile. The joint u- nit is cut-off as a slice transversely to the longitudi¬ nal direction of the profile. The joint unit shown is in¬ tended for joining aluminium profiles with a square cross section. The joint unit has a square body 2 with the same ^' dimensions as those of the hollow profiles to be joined. Reaching out from the body_ there are two legs 3,4 forming a right angle. The cross section of the legs is equal to the width in the clear of the hollow profiles, so that the latter can be pressed down over the legs which hold them firmly.

Fig. 2 shows another form of the joint unit, viz. in the shape of a T, but otherwise made in the same way as the joint unit indicated in Fig. 1. The joint unit likewise has a square body 2 from which the legs 3,4,5 protrude. The L-piece shown in Fig. 1 might be made from the T- piece shown here by cutting or milling the leg 5 away.

In Fig. 3 it is indicated how the T-piece in Fig. 2 is applied for joining the three tubular profiles 6,7,8.

It is pointed out that you will get a uniform surface, as the part of the joint unit's surface which is visible between the two meeting profiles 6,8 also is the surface of an extruded profile. Thus you will achieve a quite uniform surface of the finished frame or rack or whatever you will construct.

^•fU E

OMPI The square hole in the body elements 1 of the joint units can be closed with a plug 9 which has a square cover plate 10 corresponding to the cross section of the hollow profiles and a thickness equal to the wall thickness of the tubes. By using these plugs the final product will have a finished appearance.

When joining hollow profiles by means of the joint units shown in Fig. 1 and 2, where you want a hollow profile to be placed at right angles to the other legs of the u- nit 3,4 and 3,4,5, respectively then you use an inner tube 11 which is inserted into the width in the clear of the body element thus forming a leg. As the width in the clear of the body element is equal to that of nollow profiles to be joined, the latter as a matter of course can be pressed down over the inner tube. The inner tube can form legs on any side or on both, depending on how it is placed into the element.

Fig. 4 schematically illustrates.the five steps of buildin up a rack by means of the joint units shown in Fig. 1 and 2

Going out from the rack the Figures 6 and 7 on an enlarged scale show the cross sections cut through the lines VI-VI and VII-VII in Fig. 5. Fig. 6 shows the cross section of and end post and by reusing the reference numbers from the above, it is obvious that the end post is constructed on the basis of an L-piece as that in Fig. 1. A cross mem¬ ber 6 is fastened to the element's leg 3 and a longitudi¬ nal member 7 is pressed over the element's other leg 4. An inner tube 11 is inserted into the body element and so that it protrudes from both sides of the joint unit around which the pieces forming the post are joined. Fig. 7 shows a post within the very rack. The central joining element of the post there is the T-piece shown in Fig. 3. The longitudinal members 6,8 in this case are fastened onto the element's legs 3,5, while the cross member 7 is press down over the leg 4. In the same way as for the corner po an inner tube 11 is inserted into the body element and "a round" the tube the parts forming the post are joined, as the inner tube protrudes from both sides of the body ele^¬ ment.

Fig. 8 shows a cross section of a hollow profile and the inner tube 11 outside the "body" of the joint unit, and Fig. 9 shows the cross section of the profiles to be joined. As it is about extruded profiles these can have almost any cross section and be provided with flaps where necessary. Fig. 10 shows a simple form with a single flap 12 which supports a shelf 13 and adjusted so that the upper surface of the shelf is flush with that of the profile.

The joint unit according to the invention can be further developed to meet the demands rising from the way in which the joint unit is to be applied. It is a question of a low-priced system for private use as it is indica- ted above, or a system to be used by industry or by craftsmen where the joint units must be very strong, or it may be for exhibition purposes where a high durability as to frequent mounting and demounting is wanted.

In order to obtain a great strength of the joints or that they become very rigid the joints can be buckled to¬ gether with screws, bolts orwith rivets or the like, such as indicated by dot-and-dash lines in the Figures 6 and 7. This, however, will spoil the smooth surface and at the same time impede the joining procedure. In- stead the leg of the joint unit can be provided with a toothing 14 giving a good "bite", see Fig. 11. The too¬ thing on the joint unit's leg has the advantage that it is rectangular to the leg , as it is an extruded profile.

OMPI and thus serves as barbs preventing the profile pressed onto the leg to be pulled out. The inner tube 11 can likewise be provided with a toothing 14, this, however, will be parallel to the longitudinal direction of the tube. Fig. 13 indicates another way of strengthening the joining. The lateral faces 15 of the joint units legs 3, ,5 here have been given a minor outwards bulge making them press against the hollow profile when the latter is pressed onto the leg. To ensure the joint unit to be accurately fixed to the hollow the "root" 16 of the leg is a straight-lined piece to engage the body element 2. As is well-known aluminium is a stiff material and that is why it may be difficult to obtain the legs having the elasticity wanted. If the bulge is too "stout" it may be difficult, if not impossible, to press a hollow profile onto the legs. To remedy this a weakening groove 17 can be made at the inner side of the bulging sides of the leg. It is obvious that the toothing 14 shown in Fig. 11 and the bulging shown in Fig. 13 can be combined.

In the text above it is especially a question of joint units for hollow profiles with a square cross section; it is obvious, however, that the joint element just as well can be made for profiles having a rectangular cross section. Fig. 14 shows a joint unit for both rectangular and square hollow profiles. To illustrate this a T-piece is chosen, but the joint element might have any form. The element consists in a rectangular body element 2 with the t-wo legs 3,5 for rectangular hollow profiles. The third leg 4, however, has a square hole for a square hollow profile. This square leg has been obtained by re¬ moving the excess material from a rectangular leg. This process only demands simple tools such as saws and/or a cutter and can be automatized. In the case shown the square leg 4 is placed in the centre plane of the ele- ment, as the same quantity of material has been taken a- way from both sides of the leg. In principle it might have been displaced to either of the sides. The inner tube to be applied for this joint unit has a rectangular cross section, fitting the the body 2.

The following figures show other forms of embodiment of the joint unit according to the invention, and the same reference numbers are used for the corresponding parts in the above.

Fig. 15 shows a joint unit in the shape of an angle. As in- the above it consists of a body element 2 with two legs 3,4. Onto the leg 3 a hollow profile 6 is placed, meanwhile a hollow profile is being pressed onto the other leg 4. The letters indicated in the figure give the dimensions of the joint unit and of the hollow pro- files.

The joint unit here differs from the previous one by the legs 3,4 having a slotted, tubular part 18 at its in¬ ner wall 19. The side-walls of the legs diverge a bit from each other, reckoned from the element's body and outwards, and are widest where the inner wall 19 is placed, and they have an additional width of Y in pro¬ portion to the width X in the clear of the hollow pro¬ file. As is the case for the embodiment .in Fig. 13 the "root" 16 of the legs near the body have a cross section agreeing with the width in the clear of the profile to give an accurate mutual fixation between the joint unit and the hollow profile. To facilitate the mounting of the hollow profile the side-walls of the unit's legs at the front-end are bent against the centre line, so that they have a transverse measurement which is a bit smaller than the width in the clear of the hollow profile. When the hollow profile is pressed on to the joint unit's

OMPI leg this will give away springily because of the slot 20 of the slotted tube and the over-size of the leg and press outwards against the inner side of the hollow pro¬ file and fix it in that way. As mentioned earlier alumi- nium is a rather stiff material and therefore it may be appropriate to make weakening grooves 21 at the foot of , the leg so that the side-walls give away more easily.

In case you want the legs to have a have a greater spring power, then you can beforehand place a springy element in the the leg's tubular part 18. It may suitably be a piece of solid rubber which - when pressed together - is displaced partially through the slot of the tubular part. Instead of being solid the rubber might be tubular, and of course other materials with similar physical pro- perties can be used. Alternatively mechanical springs of various sorts, e.g. leaf springs, can be used.

This form of embodiment is very suitable, in particular if you want a mechanical, strong jointing and at the same time a possibility of repeated joinings and dis- mantlings.

Fig. 16 shows a joining with a hollow profile at right angles to the joint units leg 3,4. Again an L-piece is used the one leg 4 of which enters the plane of the paper and the other leg 3 of which points upwards and is par- tially hidden by a hollow profile 6. Here the body ele¬ ment 2 is seen as two flaps. Like previously an inner tube 11 inserted in the width in the clear of the body piece 2. In the present case the inner tube is kept from being pulled out by there being made a local out-turned bulging 22 within the body 2. For the fixation of the hollow profile 23 pressed cn to the inner tube^'11 the latter is slotted 24 from its outer end and a distance inwards and an expansion piece 25 is inserted at its ou¬ ter end. The expansion piece essentially is U-shaped and has two barbs on the outside to stop against the end of the inner tube. Like the L-piece the expansion piece is equipped with an end-wall 19 having a tubular part 18 which again has a springy element. Because of the inner tube being slotted, the expansion piece will press against the walls of the hollow profile thus kee¬ ping hold of the profile.

The plug element 9 closing the aperture in the body 2 can be built-up in the same way with an end-wall 19 and a tubular part 18 having a springy element.

Fig. 17 shows the same joint as that of Fig. 16, but instead of the expansion piece 25 and the loose plug 9 a further developmentof the inner tube 11 is applied, viz. one having a part. to be inserted into the body of the joint unit and simultaneously forming the plug 9. The other end of the inner tube is shaped as a leg on the joint unit with an end-wall 19 and a tubular piece with a springy element. This element is shown separate¬ ly in Fig. 18 in the same way as in Fig. 17, and also seen directly towards the cover plate of the plug (to the right) and directly from the side (above) . As it will appear from the figure the side-walls of that part 27 of the inner tube which is intended to sit in the width in the clear of the body element bulged outwards like the legs of the joint element shown in Fig. 13. The root 16 at the cover plate 10 is as previously at right angles to the plate 10 to obtain an accurate mutual fixation. Likewise, see the form of embodiment shown in Fig. 13, the bulged side-walls may be provi¬ ded with weakening grooves 17 to remedy the rigidity of aluminium. Fig. 19 illustrates a form of embodiment of the inner tube intended for the joining of two hollow profiles at right angles to the joint element at each side of this. Like above the centre part is intended to sit in the width in the clear of the body, whereas the two parts 28,29 protrude from each side of the joint unit, each meeting one of the two hollow profiles to be joined. The circumferential flange or plate 30 corres¬ ponds to the cover plate 10 and eleminates the groove which otherwise would be. This will appear more clearly from the figures below.

A variant of the inner tube which is shown in Fig. 18 is illustrated in Fig. 20. The difference appears from the part which is to be held in the joint unit's width in the clear. Like in Fig. -19 the element has a mating ^■ flange or mating plate 30 from which the two arms 31 protrude wearing barbs 32 at their ends, the barbs tur¬ ning inwards against each other thus fixing the plug 9. Protruding from the cover plate 10 there are likewise two arms 33 with barbs 34, intended to engage the barbs 32 on the legs of the inner tubes 31. By the mounting the legs of the inner tubes are inserted from one side in¬ to the width in the clear in the joint unit's body, while the plate element is inserted from the other side, next the two parts are pressed together till the barbs engage each other.

In Fig. 21 a blind piece or double plug of which one part is like the inner tube shown in Fig. 20 has a co¬ ver plate 10 with two arms 31 at their ends being provi- ded with barbs 32 turning against eachother. The other one is based on the principle of an end-wall 19 and a tubular part 18. The arms or sides wearing the end-wall and the tubular part have a groove 35 to engage the barbs of the other part. The two parts are from each side in¬ serted into the width in the clear of the joint unit's body till the barbs engage the grooves.

Fig. 22 indicates a fittingpiece 36 seen directly from the end and from one edge (to the right) . Below there a cross section of the fittingpiece is illustrated. The fitting piece is intended to smooth the gaps which may be found in the joints. The fitting piece is merely a slice cut off one of the profile tubes to be joined.

Fig. 23 illustrates a variant of the inner tube in Fig. 20 with the difference that the arms 31 with the barbs 32 are substituted by the principle of an end-wall and a tubular part with a springy element, just as the one applied for the plug piece shown to the left in Fig. 21.

A variant of the "double" inner tube shown in Fig. 19 . is illustrated in Fig. 24,viewed in the same way as in Fig. 19 and beneath viewed directly from the side. The only difference compared to Fig. 19 is that the inner tube has not got the mating flange or face 30 as that of Fig. 19. Instead of these the fitting frame of Fig. 22 may be used.

Fig. 25 indicates a joint corresponding to the one shown in Fig. 16. The difference is that this embodiment has an inner tube of the type shown in Fig. 20. In Fig. 26 is shown a joint having an L-piece like the one in Fig. 25 but being without an inner tube as there is no profile to be joined at right angles to the joint unit. The width in the clear of the joint unit's body here is blinded by a double plug, viz. a variant of the inner tube shown in Fig. 20. The plug piece to the left in Fig. 20 is kept, while the other part of the plug in principle is the end of the part URE

OMP shown to the right, viz. a cover plate10 having two arms with barbs turning against each other.

Fig. 27 is a three-dimensional illustration of an angle joint. Applying the elements shown in Fig. 15 and in the next figures,viz . a joint unit in the shape of an L, as the one in Fig. 15, the profiles 6,7 are fixed on to the element's legs. The profile 23 may be fastened by means of an inner tube, as in Fig. 16, or the inner tube shown in Fig. 18 may be applied.

A corresponding joint is shown in Fig. 28.

It is pointed out that the angle joint has smooth sur¬ faces, and presupposed the joining elements are made .of the same material as the profiles, an "undisturbed" sur¬ face will be obtained - unlike that of the system men- tioned in the introduction which is well-known and where the corner will have appeared black.

Fig. 29 likewise illustrates an angle joint of which the L-piece is situated in the plane of the paper. The hol¬ low profile 23 is fixed by means of an inner tube which may be of the type shown in Fig. 18 and also applying a fitting piece shown in Fig 20 and 23, where the one in Fig. 23 has been supplemented by a plug, more pre¬ cisely the plug part shown to the right in Fig. 21.

In Fig. 30 a corresponding joint is shown. Like in the previous paragraph the possibilities of getting a uniform

surface should be observed.

Fig. 31 illustrates various joining possibilities of applying the joint unit according to the invention. The double cross-joint indicated by A is based on a cross-shaped joint unit with four legs in connection with an inner tube as the one shown in Fig. 1 or the one in Fig. 24. For the T-joint indicated by B a T- shaped joint unit as indicated in Fig.s 2,3 and 7 is applied. The L-joint marked by C corresponds to those shown in Fig.s 29 and 30.

The joint marked by D corresponds to the one shown in Fig. 26.

Although the fact that only aluminium profiles have been mentioned in the above, it is certain that the joint unit and the belonging parts can be made from all extrudable materials including plastics.

If you want an especially strong structure then the joint unit according to the invention may be embodied as shown in Fig. 32 to 35. In Fig^'. .32 is shown a joint: unit in the shape of an L-piece with curved side-walls which was mentioned in connection with Fig. 13. Here the joint unit's legs 3,4 are strengthened by an internal ^• cross 37 placed as the diagonals of the legs. The side- walls of the legs then still can give away elastically when a tube is pressed on to it. Likewise the single loose parts of the joint unit have an internal cross. Such a combined inner tube and plug piece is shown in Fig. 33, corresponding to the one mentioned in connec- tion with Fig. 18.

The strengthening cross also may be combined with the springy element mentioned in connection with Fig. 15 and with weakening grooves mentioned in connection with Fig. 18. By these the keeping spring power acting on the inner side of the tube's wall will be greater.

Fig. 34 shows a cross section of an inner tube combined with a plug piece according to this principle, and above it it is illustrated seen directly from the side.

For racks and other sorts of stands exposed to very heavy loads hollow profiles with internal reinforcing ribs may be utilized. Fig. 35 shows a hollow profile seen directly from its end with a vertical reinforcing rib 39. To the left of the cross- section the same figure shows the end of the hollow profile viewed directly from the side with part of the side-wall removed. The joint unit and its belongings are provided with a slot 40 to hold the reinforcing rib of the profile. The combined inner tube and plug piece shown in Fig. 34 has such a slot 40. It will be understood that the joint unit's legs have corresponding slots.

In the previous text we have discussed joint units of which the legs are at right angles to each other and to the body. However, there is nothing to prevent the legs from forming any angle to each other and to the body. Fig. 36 shows a joint unit according to the in- vention, especially intended for being applied for the construction of rather small houses such as hothouses, tool sheds etc. As previously mentioned the joint unit comprises a body piece 2, here being square, it might, however, just as well be rectangular. Protruding from the body are two legs 3,4 of which 4 is intended for joining a vertical hollow profile 7 forming a post in the house, while the other leg 3 is intended for join¬ ing a hollow profile 6 forming a rafter. It is certain that the the joint unit can/varied in the ways already described. Fig. 37 shows a cross section of an edge profile to be used in connection with the joint unit shown in Fig. 36. The dge profile 41 is placed as a spacing piece between the single frames shown in Fig.36. The edge profile 41 is placed as a spacing piece between the single frames built-up as shown in Fig. 36. The edge profile has a part 42 corresponding to the post 7 and another one 43 corresponding to the rafter 6. The edge profile also has a body piece with a width inthe clear corresponding to body piece 2 of the joint unit. The body piece is enclosed by the two side-walls 44,45 and the flaps 46 to 49. The edge profile 41 is joined to the joint unit 42 by means of an inner tube as described earlier. It will be understood that the two profiles 6,7 forming rafter and post respectively are sawn with mi¬ tred angles and that a cut-out is made in the side-wall into which the inner tube will be inserted in the body 2.

^" The Figures 3.8 and 39 illustrate another embodiment of the joint unit according to the invention, and this is totally held in the hollowness of the hollow profiles, viz. not as above where one or more flats' of the body part has/have been visible. To the right of Fig. 38- it is illustrated how the hollow profiles 6,7 have been cut into mitred angles and totally cover the joint unit. To the left it is shown how a rectangular triangle has been cut out of the end-flats of the hollow profiles 6,7, viz. at 51,52, giving space for the joint unit's body part 2. By this it will be possible to place a hollow profile at right angles to the other two 6,7 and it will protrude from the plane of the figure. Like previously an inner tube is used for the jointing. How¬ ever, the inner tube differs from those previously men- tioned by having a part fitting into the hollowness of the body piece and another one fitting into the hollow- profile,- or in other words into the outer measures of the body piece. It will be understood that a hollow pro¬ file with the same dimensions as those of the body piece also might be used.Fig. 39 shows a jointing with a T- piece to the same princple. To the right of the figure the jointing is shown from the side on which the indivi¬ dual profiles are made to fit each other, whereas to to the left the joint is seen from the opposite side where thebody piece 2 of the joint unit is uncovered. In the figures 40 to 45 are shown quite different em¬ bodiments which are characteristic by being built-up from loose parts. Like above the joint unit comprises a body element 2 and legs protruding from this. Fig.

40 shows a body element for an L-piece. On the flats bearing the legs there are two fastening flaps 53,54 for the legs, the flaps pointing in opposite direc- tions. The legs consist of two parts 55,56 and are made of steel or spring steel; one leg is shown in Fig.

41 and the two parts 55,56 are illustrated in the Fi¬ gures 42 and 43 respectively. The part 55 which is ϋ- shaped at its top has a punching 57. The edges of the part in Fig. 42 has punchings placed opposite each other 58. The very ends of the legs are bent towards each other forming two holding flaps 59 with rounded corners and intended for being pushed under the holding ^* flaps 53,54 of the body element, see Fig. 40. The other part 56 of the leg is shown in Fig. 43 and it is also U-shaped and has a tab 60 pressed downwards at its top which fits tightly into the punching 57 of the other part 55. The ends of the legs of the part shown in Fig. 43 are likewise bent towards each other forming two flaps 61,62 fitting into the punchings 58 at the edges of the other part. Both flaps 61,62 have a square cut off 63 at each end, and by the latter a part 64 is formed to fit into the legs of the other part 55, and further they^" have a part 65 the measures of which strictly correspond to those of the cut-outs 58. Con¬ sidering the two parts 55,56 in the Figures 42 and 43 you take the part 56 and turn it 90° and put it down over the other part 55 so that the down-pressed tab 60 enters the punching 57 and the flaps 61,62 from each side engage the cutouts 58 at the edges of the legs, so that it finally looks as it appears from Fig. 41. The assembled element now, the flaps 59,59 sidewards, is put under the the body element's holding flaps 53,54. When

OMPI the hollow profile is pressed on to the leg the side- walls are pressed together and it is perfectly locked in all directions. This joint unit has a greater abili¬ ty of holding and greater rigidity than the former, as it has four side-walls against two. Fig. 44 shows the piece 55 viewed directly towards its edges (above) and to the right of that it is viewed from the left end. Be¬ low it is shown viewed directly towards one of its side- walls. In Fig. 45 the other part 56 is shown correspon- dingly.

Fig. 46 illustrates an L-shaped joint unit of which one leg is at right angles to the plane of the paper while the other one is placed in the plane of the paper, and where an extra leg is wanted at right angles to the o- ther two legs. You use a piece 66 with two holding flaps 53,54 correspondingly placed at the body element. This piece 66 is inserted into the hollowness 2 of the body element to which it is joined by means of a plug piece 9 according to j st the same principle with barbs which was indicated in Fig. 26.

This form of embodiment of the joint unit according to the invention, beyond the already described ones, has the advantage of giving a stronger joint and also of be¬ ing cheaper to manufacture.

In the succeeding figures from Fig. 47 and on one more form of embodiment of the joint unit according to the invention is shown. The joint unit is characteristic by having side-walls 67 made of steel or spring steel. Various variants of the unit are shown in the figures 48,50,51,52 and 53.

Fig. 47 illustrates a joint unit according to the inven¬ tion in the shape of an L-piece. This may have the same embodiment as to principles as was discussed in connec¬ tion with the figures 1 to 39, viz. bulging side-walls, weakening grooves, springy elements and reinforcing crossed ribs. Characteristic is the springy element 67 which in Fig. 48 is shown viewed directly from one side edge and to the right of that viewed from the side and below that directly from above. As it will appear the element is made from an rectangular piece of sheet the ends ofwhich are bent 90° thus forming two gripping flaps 68. The part of the sheet between the two gripping flaps have a bulge to the opposite side of those. For the fastening of the side-walls the leg of the joint unit has a fixing slot into which the gripping flap of the side piece is pressed in by means of a gripping flap 68. The other gripping flap 68 is held in an ante-cha ber in the leg which is enclosed by the side-walls 15 and two sup¬ porting tabs 71 opposite to each other which also may be a full wall, as shown in Fig. 54. The width of the ante¬ chamber 74 strictly agrees with that of the side pieces, thus the latter are secured from being twisted in rela¬ tion to the longitudinal axis of the legs. The side pie¬ ces are supported by the side-wall of- the slot 70 and by the supporting tabs 71. The gripping flap 68 can move freely in the ante-chambre 70, as it - when the side piece is inserted - lies tightly against the supporting flap. When a hollow profile is pushed on to the leg the side pieces will be pressed inwards, by which the gripping flap inside the ante-chamber will be deformed outwards against the leg of the end. Fig. 49 illustrates an L-piec with the side pieces 67 in place. One leg of the L-piece points to the right in the plane of the paper, while the other one points outwards from the plane of the paper and on to the latter a hollow profile 6 is fixed. It is pointed out that the width of the L-piece corresponds to the width in the clear of the .hollow profile minus two time^'s the thickness of the side pieces.

To attain a still better fixation of the hollow profiles to prevent them from being pulled out, the side pieces can be provided withabiting flap 72, see the figures 50 and 51. The biting flap 72 of the side piece shown in

OM Fig. 50 has been produced by punching and by bending the side edges. First the flap has been bent downwards be¬ tween the gripping flaps 68, next it has been bent up¬ wards to form an angle alfa and to tower a piece delta above the surface of the side piece. The sizes of the angle alfa and of the protruding part of the flap gamma are adjusted to each other in order to attain the de¬ sired power against the pulling-out of the hollow pro¬ file. In Fig. 50 the side piece is shown viewed direct- ly from the side (above) and to the right of that viewed directly from the end; below again directly from above; instead of being placed at each side of the side piece the gripping flap can be made in the middle, see Fig. 51, which shows a side piece which is viewed directly from above and from one end respectively.

In stead of the two loose side pieces 67 a clamp can be .made, see Fig. 52, in which i is shown viewed directly from one edge (left) , and to th .right of that viewed directly from the },eft; below it is viewed directly from one side flat.

As it appears from Fig. 54 the joint unitisadapted to that by the end-walls of the legs being removed and the supporting flaps being augmented to being a full wall 71. The ante-chamber 74 here is formed by the supporting wall 71 and the side-walls of the legs. The wall 73 of the clamp here is held in its place in the ante-chamber 74. As it appears from Fig. 53 the clamp may be equipped with biting flaps, like the ones described in connection with the figures 50 and 51.

In order not to weaken the cross section of the legs which must take up the sheer strains, viz. the cross section lying directly against the body element 2, the holding arrangement of the side pieces has been moved away from there, as it appears clearly from Fig. 47. In Fig. 54 a somewhat different embodiment is shown,

OMPI in which the side-wall of the body element has been moved outwards to form one side-wall of the slot 70 which will hold the side pieces of the gripping flap 68. However, by this the square or rectangular width in the clear of the body element 2 is spoiled, but this is remedied by keeping the right angles 75, so that these together with the other side-walls of the body element form a square or rectangular width in the clear. By another embodiment shown in Fig. 55 the cen- tre part 76 of the side-walls has been kept so that together with the angles 75 it forms a straight wall, andthus the square or rectangular width^" in the clear again is found within the body element.

The figures 56 to 58 illustrate different forms of embodying the inner tubes and plug pieces in accordance with the design using side pieces .just described above. Thus Fig. 56 indicates an inner tube combined with a " body piece, viz. above viewed from above, to the right of that viewed from the end-plate 10 and below viewed from the side. This element on the whole corresponds to the element described in connection with.Fig. 18

In Fig. 57 an inner tube is shown for use in connection with an L-piece or a T-piece when you wish to have a leg protruding from each side. The element corresponds to that discussed in relation to Fig. 24. In Fig. 57 it is shown viewed directly from above and from the side respectively. It should be noticed that side pieces in the shape of clamps 73 like those shown in the figures 52 and 53 can be used at the end parts, while for the centre piece only side pieces like those shown in the figures 48, 50, 51 can be used. Fig. 58 shows a double plug piece which on the whole corresponds to the one which previously was discussed in connection with Fig. 21. The arms 31, however, have been given a weakiπg 77 which makes them more elastic. The body piece to the left in the Fig. 58 has a wall 78 at right angles to the cover plate 10 at the top of which there are two obliquely placed wall-sections 79 each ending with a short piece being at right angles to the cover plate 10 and intended for engaging the barbs 32 of the other plug part shown to the right in the figure.

Returning to the elastic or yielding side piece discussed in relation to the figures 50 and 51 we see this on an enlarged scale in Fig. 59 where it is placed in a joint unit. It will be seen how the side piece 67 to the left is fastened in the slot 70 at the foot of the leg by a gripping flap 68. To the right is the other gripping flap_. laced to move freely within the ante-chamber 74. It should be noticed how the gripping flap 72 with its downwards reaching part is supported by the supporting rib 71, which will have a stabilizing effect if a hollow profile placed on the leg is affected by a pulling force. Likewise it should be noticed that the protruding part of the flap 72 will have to be longer if the angle be¬ tween the two parts of the flap is augmented and vice versa. Fig. 60 shows an embodiment of the side piece having a long sloping part 77 to catch a profile pushed on to the leg. The long sloping part passes into a shor¬ ter descending part 78. Fig. 61 shows another form of which the long sloping part 77 is exchanged for a more steeply descending part 79, and here there is a level piece 80 between the two sloping pieces. Each of the designs have their advantages, thus that in Fig. 60 facilitates the placing of a hollow profile, while that in Fig. 61 gives a greater springy power.

OM When a material is extruded there are certain limits as as to how narrow the slots can be made; thus it may be difficult to make the slot 70 in the legs for the fa¬ stening of the side pieces 67 as the latter normally will be made from a very thin steel material or from spring steel. In Fig. 63 it is shown how this problem can be avoided, viz. by placing two flaps 81opposite each other on the side-walls of the legs and two other flaps 82 side by side on the body piece. The slit be- tween the two pairs of cams 81,82 corresponds to the metal thickness of the side pieces. In Fig. 63 it is illustrated how the flaps in the level leg are placed closeto each other, while the flaps 82 on the body piece of the other leg are placed farther away from the flaps 81. To give the side pieces the optimal support it is desirable that the body-flaps 82 are placed so near the wall-flaps as at all possible. It is pointed out that there may be more than two flaps 82 on the wall of the body piece.

The T-piece shown in Fig. 62 has relation to the figures 47,54,55 and and it is about the problems as to move the fastening slot 70 of the side pieces away from the sec¬ tion near the body piece taking up the shearing forces. This design is only shown fully for the leg to the right in the figure, and there are even two solutions shown, viz. the one below within the dash-and-dot circle in it¬ self corresponding to that shown in Fig. 47, only here the corner is totally filled with materialin order to have a large cross-sectional area at the spot where the shear- ing forces will be taken up. The solution shown just a- bove it on the whole corresponds to that shown in Fig. 55.

Fig. 64 to 69 illustrate-one more form of embodiment of the joint unit according to the invention and here the body part is filled with a thread-firm material, e.g. steel. Here the legs of the joint unit are bolted on the body piece as there are threaded holes made in the flats on which the legs are to be fastened.

Fig. 64 shows a vertical cross section of a body piece 100 with an insert lol in the shape of a short profile section which is filled with a thread-firm material. This body piece is applied for making the joints shown in the figures 67, 68, 70, 71 and 72, e.g. the joints where the adjoining ends of the profiles cover the a- pertures of the body element.

Another embodiment is indicated in Fig. 65 where the insert 101 has a cover plate 102 to be applied by the joining and where one of the body element's apertures will be visible as it is illustrated in the figures 66 and 69. The total width of the body element and the cover plate corresponds to the outer width of the pro¬ files.

As it was the case by the previous forms of embodiment the legs of the joint unit may hace various shapes. In the figures 73 to 75 three different designs are shown, and in Fig. 76 a joint unit in the shape of an L-piece is shown; here one leg, for the sake of a better illu¬ stration, is shown in Fig. 73, whereas the other leg appears from Fig. 74. The insert and the cover plate in Fig. 65 have bee applied here.

The leg shown in Fig. 73 comprises two end-pieces 103, 104, here made of impact-proof polystyrene, which are kept at a certain distance from each other by a space collar 105 fitting the inwards turning part of the end-pieces. The outside measures of the end-pieces tightly fit the inner measures of the hollow profiles, while the cross section of the collar 105 is smaller.

■lOMPI W1P Thus the hollow profiles rest on two fixed points of support. In the end-pieces there is a central bored through-hole for a bolt which can be screwed into a tapped hole in the body piece. The end-piece 104 is provided with a countersinking 107 for the bolt head and a washer 108.

If you want a permanent and strong joint the flats and surfaces of the leg can be smeared with glue be¬ fore the joining takes place.

Another design is shown in Fig. 74 where the whole leg is made of impact-proof polystyrene and the supporting surfaces 109,110 of the hollow profile are provided with jags to increase the resistance against the pro¬ file being pulled off the leg. The central bore hole for the bolt which besides may be an Allen screw here is has a supporting sleeve 112.

To prevent the leg from being turned in proportion to the body part the leg may be provided with one or more short pins fitting into holes in the body part. The de- sign shown has such four pins 113.

In the same way as was the case at the designs shown in the figures 50, 51, 52 and 59 the leg may be e- quipped with protruding springy flaps which lock the hollow profile further in proportion to the leg.

Fig. 75 illustrates such a design which is a variant of those shown in Fig. 74, yet it differs as to the fact that the supporting sleeve is left out. At two opposite flats of the leg there are made slots 114 facing each other and each holding a springy clamp 115. To prevent the springy clamp 115 from being torn off its legs have been given a bending 116 against each other which is caught by an edge in the slot. When a hollow profile is pushed on to the leg the legs of the

f _OMPI springy clamp are pressed into the slot. If you try to pull the hollow profile off, this will be prevented by the ends of the springy clamp pressing against the in¬ ner side of the hollow profile and biting on to them. The text above mainly has described forms of embodiment where square hollow profiles have been applied, however, the invention is not limited to those. The last-men¬ tioned form of embodiment especially is applicable in connection with hollow profiles with a circular cross section.

Fig. 77 shows a form of embodiment intended for round tubes, and here the body part is prepared with ^'rounded corners in order to obtain a aesthetically pleasant im¬ pression of the finished joint. This joint unit is e- specially applicable for the joining of brass tubes where the final result is exceptionally fine.

The joint unit's legs 118,119 here are tube sections with a recessed part between the contact faces 109,110 for the tubes. It is obvious that designs like those shown in the figures 73 to 75 can be applied.

As cover plate 102 to close the aperture of the body element a slightly domed, circular disc is used; it is pressed in its place in the body element by its spring power. Alternatively the cover plate can be flat and provided with a pin 120,.at the end of which a pla- . stic material 121 is placed and made sothat it can be pressed into the tapped hole of the leg.

In relation to the designs shown in the figures 64 to 79 it is obvious that the body element must be provi- ded with short, threaded pieces on to which the legs are screwed being provided with tapped holes.

As it is evident, the joint unit of the invention of¬ fers many design variations each of which having its advantages.

OAΪPI

Claims

What is claimed is:

1. A joint unit for hollow profiles, e.g. aluminium pro¬ files, which joint unit (1) has a body part (2) with legs (3,4,5) protruding from this and the legs (3,4,5) fitting into the hollowness of the profiles (6,7,8,23), and c h a r a c t e r i z e d b y the joint unit (1) being manufactured from extruded hollow profiles as slices cut-off transversely to the longitudinal direc¬ tion of the profiles and the cross section of the pro¬ file forming the cross section of the unit's (1) legs (3,4,5) and the unit (1) being cut-off the hollow pro¬ file in a thickness corresponding the edge length of the width in the clear of the profiles (6,7,8,23) to be joined.

2. A joint unit as claimed in claim 1 c h a r a c t e - r i z e d . b y the body part (2) having a width in the clear for the insertion of an inner tube (11) with a square or rectangular cross section, the tube forming legs for hollow profiles (6,7,8,23) which are to be joined at right angles to the other legs (3,4,5) of the joint unit (1) .

3. A joint unit as claimed in claim 1 or 2 c h a r a c t e r i z e d b y at least one springy element being placed between the side plates of the legs and made to affect the side plates with an outwards directed power.

4. A joint unit as claimed in claim 3 c h a r a c t e r i z e d b y the end-wall (19) of the legs having a slotted tubular part (18) in which an elastic element, e.g. a rubber or the like is embedded.

5. A joint unit as claimed in claim 1 or 2 c h a r a c¬ t e r i z e d b y the fact that at one end of the legs

BUR

OMP preferably the end nearest to the body part (2) there are two slots (70) situated opposite each other and reaching to the edges of the legs, in which a sheet- shaped spring element (67), preferably of spring steel, by means of a bent gripping flap (68) is embedded so that it at least partially covers the total length of the leg.

6. A joint unit as claimed in claim 5 and c h a r a c- ^'t e r i z e d b y there being formed at least a biting flap (72) in the sheet-shaped spring element (67) , the end of which protrudes from the spring element and by this engages a hollow profile which is placed on to the leg.

7. A joint unit as claimed in claim 5 and c h a r a c- t e r i z e d b y the fact that the slot into which the sheet-shaped spring element (67) is placed is formed by two opposite each other sitting flaps (81) on the in¬ ner flat of the legs and at least^' one, preferably two, flaps (82) protruding at right angles from the body part (2) and made so that the gripping flap (68) of the spring element just can be seated between the side-flats of the two flaps (81) of the legs and the end of the flap (82) of the body part.

8. A joint unit as claimed in claim 1 and σ h a r a σ - t e r i z e d b y the fact that it comprises a distinc body part (2) with at least two away from each other di¬ recting fastening flaps (53,54), their flanges being ap¬ proximately parallel to the side-wall of the body part, and that its legs are formed by two U-shaped pieces (55,56) prefereably of spring steel and assembled to for a closed box, as the ends (61,62) of the legs of one par are bent against each other and fit into cutouts (58) in the sides of the legs of the other part (55) , and under the cutouts (58) the ends (59) of the legs of this part (55) are also bent against each other and intended to be

^*BU E

OMP inserted sidewards under the fastening flaps (53,54) of the body part, and that in the upper side of the one part (55) there is made a cutout (57) and a pressed-out tab (61) in the other part (56) fitting into the cutout (57) thus locking the two parts together.

9. A joint unit as claimed in the claims 1 and 2 and c h a r a t e r i z e d b y comprising a plug piece (10) which corresponds to the body part (2) of the u- nit and has a part (9) fitting into the hollow of the body part.

10. A joint unit as claimed in claim 9 and c h a r a c¬ t e r i z e d b y its plug piece (10) being provided with barbs (34) designed to engage barbs (32) of an in¬ ner tube or of another plug piece (10) .

11. A joint unit as claimed in claim 1, c h a r a c t e¬ r i z e d b y the body part (100) being completely or partly filled with a thread-firm material, e.g. com¬ pressed steel, and there being tapped holes in the body part for fastening the legs by means of threaded pins.

12. A joint unit as claimed in claim 10, c h a r a c ¬ t e r i z e d b y the legs having a central through- going bore for a threaded pin in the shape of a bolt (106) .

13. A joint unit as claimed in claim 1 or 11, c h a - r a c t e r i z e d b y comprising a plug piece in the shape of a slightly domed, elastic disc (Fig. 78) for the closing of an uncovered aperture in the body part (100) .