DE4220587A1 - Mutually fixing two moulded parts - using injection-moulded thin walled sleeve with side detent opening for receiving detent block - Google Patents

Abstract

The sleeve (2) forming the socket has a circular or elliptical cross-section and is radially deformable. The detent block on the other part engages in the opening (6) on the sleeve wall (5) by a detent nose (14) which extends across the insert direction. The sleeve is supported radially by guide faces. The detent member can have an insert opening (3) for the sleeve whereby the inner faces running parallel to the insert direction form the support and guide faces. The ID of the semi-cylindrical inner wall area of the insert opening, and the diametric distance between the inner wall area and the opposite flat wall area of the insert opening (3) pref. correspond to the OD (D) of the sleeve. USE/ADVANTAGE - Secure fixing with controlled radial deformation of the sleeve. Low cost mfr.

Description

The invention relates to a fastening device for mutual Fi Fixing two molded parts, in particular made of plastic, according to the generic term of claim 1.

In connection technology, fastening devices are mutually compatible Gen fixation of molded parts with an existing plastic receiving part on the first molded part and an insertable therein and with the sem lockable locking part on the second molded part as a so-called clips or Snap fasteners known. For this purpose, the locking part is, for example, bol zen-like design and points from its insertion end two diametrical, cross-shaped notches on which the stand permanent bolt wall forms flexible locking arms in the bolt radial direction. At the free ends are radially outward locking lugs det, which in corresponding recesses approximately in the form of an annular groove snap into the receiving part.

The fact that these known fastening devices are disadvantageous is the fact che that with the production of both the receiving and the locking part elaborate injection molds are necessary. Furthermore, the locking arms of the locking part are very sensitive to breakage, which means the reliability of such fasteners suffers. Also seems the fixative effect of such known fastening devices basically in need of improvement.

The invention has for its object a fastening device the generic type in such a way that the one hand the injection molds necessary for their manufacture are designed to be less complex can be and on the other hand reliability and fixative effect of such Fasteners are improved.

This object is achieved by the in the characterizing part of the claim 1 specified features solved. The appropriate training of the reception partly as a thin-walled sleeve is with particularly low injection technology real tool costs and with the least possible use of materials  sizable. For the locking with the locking part, one is sufficient on the sleeve side latch opening, which also reduces tooling.

Despite the simple, relatively filigree design of the receiving part created a reliable fixation between this and the locking part, what on the one hand by the engagement of the locking lug arranged on the locking part in the corresponding locking opening of the sleeve and on the other hand thereby ge It is ensured that the locking part extends in the joining direction supporting and has guide surfaces for radial support of the sleeve. These Support leads to a controlled radial deformation of the sleeve during the assembly of the locking part and sleeve, which is a Protection of the sleeve material and on the other hand a reliable fixation of the engagement of the locking lug in the locking opening.

The sub-claims 2 to 12 characterize an advantageous embodiment the fastening device according to the invention. The according to claim 2 The insertion opening provided is particularly small technical effort can be produced, the provided according to the invention Support and guide surfaces in the form of the inner surfaces of the insertion opening are formed in a structurally very simple manner.

The measures according to claims 3 and 4 ensure that the sleeve when inserting into the insertion opening of the locking part through the Locking nose only radially in the sub-area acted upon by this is deformed inside. The adjacent areas of the sleeve wall can due to the arched cross-sectional shape of the Avoid the insertion opening of the available space radially outwards, resulting in a particularly low material stress despite the sleeve deformation arises. This is also favored by the fact that Sleeve in its semi-cylindrical opposite the locking opening Wall area full of the corresponding semi-cylindrical inner wall area of the insertion opening.

By the measures specified in claims 5 and 6, he is is sufficient that the fastening device according to the invention based on the Joining direction builds particularly compact and the two to be connected  Molded parts are thus held in a particularly close relationship to one another can be. This extends the possible uses of the fiction moderate fastening device considerably.

By designing the fastening device according to claim 7 on the one hand, the effort required to join the recording and Locking part reduced and on the other hand a reliable fixation of the achieved the molded parts to be connected. In particular, a Va Riation of the angle of inclination of the steeply falling latching flank a separation the connection easy, difficult or only using a special Tools are made possible.

By the measure specified in claim 8, the support and Füh behavior of the support and guide surfaces further optimized.

By designing the fastening device according to claim 9 becomes a favorable compromise between the least possible deformity tion of the sleeve when joining the receiving and locking part and one reliable maintenance of the locking engagement between the locking part and the locking opening achieved.

An alternative to the training according to claims 2 to 9 design of the fastening device according to the invention is in the An say 10 to 17 specified. So is as a locking part according to claim 10 essentially designed as an insertable into the sleeve block. Through the angular formation of the cross-sectional contour of the block and its diametra The excess of the inner diameter of the sleeve is the latter at Insertion of the block against its restoring force in the radial direction deformed. When snapping in in the area of a longitudinal edge an undercut trained latch of the block in the Rastöff tion of the sleeve, the shape restoring force of the sleeve is used to a deep engagement of the locking lug in the locking opening and a reliable Ensure the latching is maintained. It is also in the locking position compared to the maximum deformation when turned on lead the block into the sleeve slightly less deformation of the sleeve in Maintain radial direction. As a result, they are not behind  cut for the long edges of the block in intimate contact with the sleeve, causing the block and thus that with it connected molded part stable in a defined relative position the sleeve and thus the second molded part is held.

In the design of the cross-sectional contour specified in claim 11 of the block is the material because of its rounded longitudinal edges stress on the sleeve in its radial deformation in acceptable Limits kept, so that no harmful to the sleeve wall Notches leading to cracks or breaks are exerted. By the qua The cross-sectional contour remains in the locked position of the block with the sleeve three contour longitudinal edges of the block in essentially line aren contact with the inner wall of the sleeve of the receiving part. The result created three-sided support of the block in the sleeve is static defined, whereby the molded parts to be connected also in a defi held position to each other. It should be noted that one square cross-sectional contour, for example through a full square cross-section, but also through two symmetrically crossing webs can be formed, the longitudinal side edges of the actual square Form cross-sectional contour.

Due to the feature specified in claim 12, the introduction is the block in the sleeve relieved and a gradual and therefore mate Rial-friendly deformation of the sleeve reached.

The recess provided in claim 13 is reduced in the end face considerably the material required to produce the block.

The measures specified in claims 14 and 15 reduce the Manufacturing effort for the block, since this together with it orderly molded part can be manufactured. It also reduces by the intended, the undercut to form the latch of the Blocks continuing opening in the flat molding of the tool Effort for shaping the latch. The undercut and the opening are formed together by a shape projection, that of the forming the block-side boundary surface of the molded part  Form surface of the tool protrudes. The molding is so despite the hin Easy to demould the cutting.

By the measure specified in claim 16, the locking connection ge between the block and the sleeve in a relatively simple manner be solved.

The value ranges specified in claim 17 for the ratio of Outer circumference of the cross-sectional contour of the block to the inner circumference of the Sleeve or the maximum diametrical cross-sectional contour dimension for the In The inner diameter of the sleeve is an optimal compromise the most secure locking of the block in the sleeve and one the lowest possible material stress on the sleeve.

This has a favorable effect in all two embodiments 18 specified ratio of the wall thickness of the sleeve to the outside knife out.

By the embodiment according to claim 19, the manufacturer is in turn technical effort for the manufacture of the fastening device reduced.

Claim 20 relates to the so-called wall-rib-thickness ratio Injection molded parts made of plastic. Basically, with a flat shape part, which on its back facing away from the visible side by ribs is reinforced, the wall thickness of the molded part is at least twice as large be like the thickness of the ribs, otherwise the ribs are on the Would be visible side. In the fastening device according to the invention direction, on the one hand, the sleeve can be made so thin-walled, that it does not appear on the visible side of the molded part, other on the one hand, despite this thin wall, sufficient stability of the Connection guaranteed.

Claims 21 to 23 are generally the best for a molded article hend from two essentially flat moldings or on its Ver directed as a chair seat or backrest body. Here  can a fastening device according to the invention several times for fixie tion of two molded parts can be arranged together. It comes with for example, a configuration of four such fasteners under arrangement in a square. As an application example is the use of such fasteners in chair seats or to call backrest bodies, the one molded part with sleeves of the fastening devices provide the bottom or rear Ver glare part and the second molded part with locking parts of the fastening directions provide the upholstered cover of the seat Form surface or backrest body. This makes a particularly sta bile connection between the two moldings mentioned. The flat shaped parts are namely in a parallel to their main plane Fixed level so that only a linear extraction of the Sleeves from the locking parts is possible at all, but because of Latching is effectively prevented. Swiveling the Locking parts from the sleeve around a lying in the area of the locking Swivel axis is also due to the mutual fixation of the molded parts prevented.

Further features, details and advantages of the invention are according to following description can be seen in which an embodiment of the Subject of the invention explained in more detail with reference to the accompanying figures becomes. Show it:

Fig. 1 is an assembly drawing of receiving and locking part of a fastening device according to the invention, in a first alterna tive embodiment in longitudinal section with the two parts in each other position of detached

Fig. 2 is a view analogous to FIG. 1 with the receiving part in a partially inserted into the locking part position,

Fig. 3 is a view analogous to FIG. 1 with receiving and locking part in ge genseitiger Verraststellung,

Fig. 4 is a sectional view according to section line IV-IV of FIG. 1,

Fig. 5 is a sectional view according to line VV of Fig. 2,

Fig. 6 is a sectional view according to sectional line VI-VI of Fig. 3,

Fig. 7 is an assembly drawing of receiving and locking part of a fastening device according to the invention, in a second alter native embodiment in longitudinal section with one another in the sleeve and block of detached position

Fig. 8 is a view analogous to FIG. 7 with development sleeve and block in mutually approach Stel,

9 is a view analogous to FIG. 7 inserted to the block in a partially into the sleeve position.,

Fig. 10 is an enlarged view similar to FIG. 7, with sleeve and block in mutual Verraststellung,

Fig. 11 is a front view of the block of the fixing device from the direction of arrow XII in FIG. 7,

Fig. 12 is a view of the sleeve of the fastener of arrow Rich tung XII of FIG. 7,

Fig. 13 to 15 sectional views through the mounting device ent long section lines XIII-XIII of FIG. 8, XIV-XIV in FIG. 9 and XV-XV in FIG. 10,

Fig. 16 is a front view of a chair backrest body with modern fiction, fastening devices,

Fig. 17 is a section along the section line XVII-XVII of FIG. 16 and

Fig. 18 is a sectional view taken along the line XVIII-XVIII according to Fig. 16.

The mounting device illustrated in FIGS. 1 to 6 consists of the (Darge in Figs. 1 to 6 partially notified) as a receiving part in a first mold part 1 integrally molded sleeve 2 and the Einschuböff voltage 3 in the second (also only partially shown) Molding 4th The insertion opening 3 represents the locking part of the fastening device.

The sleeve 2 has a flat cylindrical shape and is in its sleeve senwand 5 with a lateral, rectangular latching opening 6 , the length in the longitudinal direction of the sleeve corresponds to approximately a quarter of the sleeve length and its width in the transverse direction of the sleeve corresponds to approximately half the outer diameter of the sleeve. The latching opening 6 is shifted towards the free En de 7 of the sleeve 2 .

In the exemplary embodiment shown, the inside diameter of the sleeve is 17.35 mm and the outside diameter is 19.67 mm, so the sleeve has a wall thickness of 1.16 mm. The molded part 1 connected in one piece to the sleeve 2 has a wall thickness of approximately 3 mm, so that the so-called rib-wall thickness ratio is less than 1: 2.

The insertion opening 3 is arranged in a thickening area 8 of the wall 9 of the associated molded part 4 and is designed as a continuous opening. It is approximately arch-shaped in cross section, so that its inner surfaces running parallel to the insertion direction E have a substantially semi-cylindrical inner wall region 10 with adjoining straight flanks 11 , 12 and a flat inner wall region 13 opposite the semi-cylindrical inner wall region 10 . The latching lug 14 is arranged in the plane spanned by the wall 9 of the molded part 4 on the flat inner wall area 13 approximately in relation to the narrow and width of the insertion opening 3 . The locking lug 14 has a relative to the A direction of insertion E of the sleeve 2 flat rising ramp 15 and an adjoining, steeply falling latching flank 16 . The inclination angle of the leading edge 15 is 28 °, the locking edge 16 be about 33 °. The height of the locking lug 14 transversely to the insertion direction E is about 2 mm and thus about 10% of the free diameter of the insertion opening 3 . Immediately in front of the locking lug 14 , the insertion opening 3 has a step-shaped, chamfered cross-sectional taper 17 .

The inner diameter of the semi-cylindrical inner wall region 10 and the diametrical distance d between this inner wall region 10 and the opposite, flat inner wall region 13 of the insertion opening 3 corresponds to the outer diameter D of the sleeve 2 .

When the sleeve 2 is inserted into the insertion opening 3 , the sleeve 2 rests with its semi-cylindrical wall area opposite the latching opening 6 on the corresponding semi-cylindrical inner wall area 10 of the insertion opening 3 , so that the latter wall areas act as support and guide surfaces for the radial support of the sleeve 2 . Furthermore, the wall section 18 located between the free end 7 of the sleeve 2 and its latching opening 6 is deformed radially inward when it hits the ramp flank 15 of the latching lug 14 , as is particularly evident from FIG . The regions of the sleeve wall 5 which laterally adjoin the wall section 18 accordingly deviate radially outwards, which is possible on both sides of the latching lug 14 due to the free space formed by the arched cross-sectional shape of the insertion opening 3 . When the sleeve 2 is pushed further into the insertion opening 3 , the locking lug 14 engages in the locking opening 6 , the sleeve 2 resiliently springs back into its original shape. Due to the mutual latching, the sleeve 2 is reliably fixed in the insertion opening 3 counter to the insertion direction E and by its radial support also in the radial direction.

The fastening device shown in FIGS . 7 to 15 consists of two parts, namely the sleeve 22 which is integrally molded as a receiving part onto a first molded part 21 (partially shown in FIGS . 7 to 10) and which has a flat cylindrical shape. The thin-walled sleeve 22 has in its sleeve wall 23 a lateral, approximately square latching opening 24 , the length of which in the longitudinal direction of the sleeve corresponds to approximately half the length of the sleeve and the width in the transverse direction of the sleeve corresponds to approximately one third of the outer diameter of the sleeve. The latch opening 24 is displaced in the longitudinal direction away from the free end 25 of the sleeve 22 in the direction of the molded part 21 .

In the illustrated embodiment, the inner diameter of the Sleeve Shirt is se 22 33 mm and the outer diameter of 35 mm, the sleeve 22 thus has a wall thickness of 1 mm. The integrally connected with the sleeve 22 ne molded part 21 has a wall thickness of 3 mm, so that the so-called te rib-wall thickness ratio is 1: 3.

With its free end 25, the sleeve 22 forms the insertion opening for the engaging part on the second molded part 27 , which is designed as a block 26 and is likewise only indicated in a partial section in FIGS. 7 to 10. The block projects from the molded part 27 at approximately a right angle. As is particularly clear from FIGS. 10 and 11, the block 26 has an approximately square cross-sectional shape with rounded longitudinal edges 28 . The free end 29 of the block which can be inserted into the sleeve 22 is tapered from about half its narrow end in the direction of insertion 30 . Its end face 11 pointing in this direction 30 is provided with a truncated cone-shaped recess 32 , the bottom 33 of which is arranged with the surface 34 of the molded part 27 pointing in the insertion direction 30 .

In the region of a longitudinal edge 28 ', the block 26 between its Wur zelbereich on the molded part 27 and about half its length a trailing Tailoring 35, whose base 36 gonal cross section approximately parallel to the slide between the two of the longitudinal edge 28' adjacent Längskan th 28 extends . The undercut 35 continues into a rectangular opening 37 in the molded part 7 , the base 36 of the undercut 35 merging flush with a side surface 38 of the opening 37 . By the undercut 35 , the side latch 39 is formed at the free end 29 of the block 26 .

As is particularly clear from FIGS. 8 to 10 and 13 to 15, the maximum diametrical cross-sectional contour dimension of the block, that is to say the diametrical distance a between two opposite longitudinal edges 28 of the block 26, has an oversize compared to the free inner diameter of the sleeve 22 . In the exemplary embodiment, the diametrical distance a is 35 mm, whereas the inner diameter of the sleeve is 33 mm. As a result, when the block 26 is inserted into the sleeve 22, the latter is deformed in the radial direction, starting from the circular cross-sectional shape shown in FIG. 12 into the approximately square cross-sectional shape shown in FIG. 14 with rounded corner areas 40 and slightly spherical side areas 41 ( Fig. 9, 14). Reaches the block 26, its maximum insertion position (Fig. 10, 15) snaps the latch 39 into the locking opening 24 of the sleeve a, whereby the counter to the insertion direction 30 facing locking surface 42 of locking lug 39 pointing in the direction of insertion 30 snap edge 33 of the latching opening 22 24 engages behind. Due to the restoring force inherent in the sleeve 2 , the block 26 is additionally displaced in the direction of engagement of its locking lug 39 which is at right angles to the insertion direction 30 , as a result of which the locking engagement between the locking lug 39 and the locking opening 24 is further reinforced and secured. In this position shown in FIGS. 10 and 15, the sleeve 22 remains slightly de-formed in the manner indicated above.

The deformation of the sleeve 22, in particular when the block 26 is inserted ( FIGS. 9, 14), can be selected appropriately on the one hand the ratio between the outer circumference of the cross-sectional contour of the block 26 and the inner circumference of the sleeve 22 and on the other hand the ratio between the maximum diametrical cross-sectional contour dimension of the Blocks 26 and the inner diameter of the sleeve 22 are affected. In the exemplary embodiment shown, the outer circumference of the block 26 is approximately 97.3% of the inner circumference of the sleeve 22 . The diametrical distance a is approximately 106% of the inner diameter of the sleeve 22 .

In Figs. 16 to 18 a backrest body 44 is shown an office chair as an example of the application of the fastening device according to Invention. The body 44 consists essentially of two flat, slightly curved and ergonomically shaped parts, namely the cover 45 forming the back of the backrest body 44 made of poly propylene and the padding (not shown) carrying cover 46 made of regenerated polyester. In the four corner areas of the panel 45 and the cover 46 , a fastening device according to the invention is provided. So there are four sleeves 22 arranged in the square to the diaphragm 45 and four blocks 26 aligned to the cover 46 so that they are injection molded in one piece.

Claims (23)

1. Fastening device for mutually fixing two molded parts ( 1 , 4 , 21 , 27 ), in particular made of plastic

• - An existing plastic receiving part on the first molded part ( 1 , 21 ) and
• a latching part (insertion opening 3) on the second molded part ( 4 , 27 ) which can be locked with these, characterized in that
• - That the receiving part is formed by a thin-walled, deformable in the radial direction, circular in cross section or elliptical sleeve ( 2 , 22 ), the sleeve wall ( 5 , 23 ) has a lateral latching opening ( 6 , 24 ) and
• - That the locking part (insertion opening 3 , block 26 )
• - Can be joined together in the longitudinal direction of the sleeve with the sleeve ( 2 , 22 ),
• - For mutual locking with the sleeve ( 2 , 22 ) extending transversely to the joining direction (insertion direction E, insertion direction 30 ), in the locking opening ( 6 , 24 ) of the sleeve ( 2 , 22 ) engaging locking lug ( 14 , 39 ) and
• is provided with support and guide surfaces which extend in the joining direction (insertion direction E, insertion direction 30 ) for radial support of the sleeve ( 2 , 22 ),
  a radial, elastic deformation of the sleeve ( 2 , 22 ) taking place at least when the latching part (insertion opening 3 , block 26 ) and sleeve ( 2 , 22 ) are joined together.

2. Fastening device according to claim 1, characterized in that the latching part has an insertion opening ( 3 ) for the sleeve ( 2 ), the parallel to the insertion direction (E) extending inner surfaces (inner wall regions 10, 13 ) of the insertion opening ( 3 ) as a support - And guide surfaces at least partially rest on the outside of the sleeve ( 2 ) and the locking lug ( 14 ) protrudes inwards from an inner surface (flat inner wall region 13 ) of the insertion opening ( 3 ) transversely to the insertion direction (E). 3. Fastening device according to claim 2, characterized in that the insertion opening ( 3 ) is approximately arch-shaped in cross section, the essentially semicylindrical inner wall region ( 10 ) of the insertion opening ( 3 ) formed on the corresponding outer wall region of the sleeve ( 2 ). bears as a support and guide surface and the locking lug ( 14 ) on the semi-cylindrical inner wall region ( 10 ) opposite flat wall region ( 13 ) of the insertion opening ( 3 ) is arranged. 4. Fastening device according to claim 3, characterized in that the inner diameter of the semi-cylindrical inner wall region ( 10 ) and the diametrical distance (d) between this inner wall region ( 10 ) and the opposite, flat wall region ( 13 ) of the insertion opening ( 3 ) the outer diameter (D ) corresponds to the sleeve ( 2 ). 5. Fastening device according to one of claims 2 to 4, characterized in that the latching lug ( 14 ) is arranged approximately in the center of the insertion opening ( 3 ) in the insertion direction (E). 6. Fastening device according to one of claims 2 to 5, characterized in that the insertion opening ( 3 ) of the latching part as a through opening in a thickening area ( 8 ) of the wall ( 9 ) of the associated molded part ( 4 ) is arranged, wherein the latching lug ( 14 ) lies in the plane spanned by the molded part wall ( 9 ). 7. Fastening device according to one of claims 2 to 6, characterized in that the latching lug ( 14 ) based on the insertion direction (E) of the sleeve ( 2 ) has a gently rising run-up flank ( 15 ) and an adjoining steeply falling latching flank ( 16 ) having. 8. Fastening device according to one of claims 2 to 7, characterized in that the insertion opening ( 3 ) has a step-shaped, preferably chamfered cross-sectional taper ( 17 ). 9. Fastening device according to one of claims 1 to 8, characterized in that the maximum height of the latching lug ( 14 ) is approximately 10% of the outer diameter (D) of the sleeve ( 2 ). 10. Fastening device according to claim 1, characterized in that the latching part of a in the longitudinal direction (insertion direction 30) in the sleeve ( 22 ) insertable block ( 26 ) is formed,

• - whose cross-sectional contour is polygonal,
• - Its maximum diametrical cross-sectional contour dimension (diametrical Ab stood a) has an oversize compared to the inner diameter of the sleeve ( 22 ) and
• - In the region of a contour longitudinal edge (longitudinal edge 28 ) has an undercut ( 35 ) to form a latching nose ( 39 ) which can be snapped into the latching opening ( 24 ) of the sleeve ( 22 ).

11. Fastening device according to claim 10, characterized in that the cross-sectional contour of the block ( 26 ) is square with rounded longitudinal edges ( 28 , 28 '). 12. Fastening device according to claim 10 or 11, characterized in that the insertable into the sleeve ( 22 ) free end ( 29 ) of the block ( 26 ) is tapered in the insertion direction ( 30 ). 13. Fastening device according to one of claims 10 to 12, characterized in that the block ( 26 ) in its in the insertion direction ( 30 ) facing end face ( 31 ) has a narrow diameter recess ( 32 ). 14. Fastening device according to one of claims 10 to 13, characterized in that the block ( 26 ) is integrally formed with the molded part ( 27 ) assigned to it. 15. Fastening device according to claim 14, characterized in that the block ( 26 ) protrudes from a flat shaped part ( 27 ) approximately at right angles with respect to its flat plane and the undercut ( 35 ) to form its locking lug ( 39 ) into a through the shaped part ( 27 ) continues through opening ( 37 ). 16. Fastening device according to one of claims 10 to 15, characterized in that the latching lug ( 39 ) of the block ( 26 ) is chamfered or rounded on its latching surface ( 42 ) which points against its insertion direction ( 30 ). 17. Fastening device according to one of claims 10 to 16, characterized in that the outer circumference of the cross-sectional contour of the block ( 26 ) about 95% to 98% of the inner circumference of the sleeve ( 22 ) and the maxi male diametrical cross-sectional contour dimension (diametrical distance a) of the block ( 26 ) is approximately 105% to 108% of the inner diameter of the sleeve ( 22 ). 18. Fastening device according to one of claims 1 to 17, characterized in that the wall thickness of the sleeve ( 2 , 22 ) is 5 to 7% of the outer diameter (D) of the sleeve ( 2 , 22 ). 19. Fastening device according to one of claims 1 to 18, characterized in that the sleeve ( 2 , 22 ) at its end facing away from the free end ( 7 , 25 ) is integrally connected to the molded part ( 1 , 21 ) assigned to it. 20. Fastening device according to one of claims 1 to 19, characterized in that the ratio of the wall thickness of the sleeve ( 2 , 22 ) to the wall thickness of the one-piece molded part ( 1 , 21 ) is smaller than 1: 2. 21. Shaped body, consisting of two essentially flat shaped parts, characterized in that to fix the two molded parts together of the several fastening devices according to one of the aforementioned An sayings are provided.   22. Shaped body according to claim 21, characterized in that four in Such a fastening devices arranged in a square are provided are. 23. Shaped body according to claim 21 or 22, characterized by its use as a chair seat surface or backrest body, wherein the one molded part with sleeves ( 22 ) of the fastening devices, the bottom or rear facing part (panel 45 ) and the second molded part with locking parts (block 46 ) of the fastening devices form the cover part provided with a padding (cover 46 ) of the seat surface or backrest body ( 44 ).