A fastening of an assembly part onto a carrier part

Abstract: A fastening of an assembly part (40) on a carrier part (50) with at least one fastening screw (10) which comprises a screw head (11) with engaging surfaces for a tool, a screw shank (13), at least one radial projection (14) on the screw shank (13) at a distance from the screw head (11) and a thread (15) at least at the distance of the radial projection (14) from the screw head (11), with a sleeve (20) with an inner diameter which corresponds at least to the outer diameter of the radial projection (14) and of the thread, which is a narrow location (22) with an inner diameter smaller than the diameter of the radial projection (14) but at least as large as the outer diameter of the screw shank (13) between the screw head(11) and the radial projection (14), and which at the upper end comprises a head flange (23) and at the lower end a foot flange (24) into which the fastening screw (10) is inserted, wherein the narrow location (22) is snapped over the radial projection (14) of the fastening screw (10) and the screw head (11) is allocated to the outer side of the head flange (23).

Description: The invention relates to a fastening arrangement securing an assembly part to a carrier part according to the preamble of claim 1. One possible application region of the invention is in automobile technology. A case of application is the fastening of the cylinder head cover to a cylinder head. Another is the fastening of an intake chamber to a motor. Relevant fastenings with which a fastening screw is arranged telescopically in a sleeve, wherein a knurling of the screw shank at a distance from the screw head in cooperation with a necking at the upper end of the sleeve ensures an unlosability of the fastening screw and sleeve, are already known from US-A-5.807.052. In one known embodiment a head flange of the sleeve is supported on a rubber ring which is pressed into a receiver of a cylinder head cover. A foot flange of the sleeve is buttoned into a through-bore with an undercut of a further rubber part which is arranged between the cylinder head cover and the cylinder head. By way of this a decoupling is effected, i.e. the hard screw head as well as the sleeve are not pressed directly against the cover which may consist of plastic. On the other hand the sleeve of metal prevents an excess pressing of the rubber parts. With this an unlosable prior assembly of the screw, sleeve and rubber parts to the cylinder head cover is possible which permits a transport in any position up to assembly on the cylinder head. It is however of a disadvantage that the screw, when mounting the cylinder head cover, with its lower end may slide over the sealing surfaces of the cylinder head and damage these. With long screws the knurling may even press against the necking of the sleeve and loosen the prior assembly. With another known fastening likewise a rubber ring is arranged between the head flange of the sleeve and the assembly part. The rubber ring has a collar with three hooks distributed on the circumference which engage behind the undercuts in a through-bore of the assembly part. The collar however must have a certain thickness so that on pressing into the through-bore they are not pressed axially together. Because the hooks form the only securement this fastening is not adequately safe in transport. Furthermore the telescoping ability is limited by the abutment of the knurling on the necking so that there prevails a relatively long screwing out of the sleeve and thus the guiding as well as the assembly of the cylinder head cover (assembly part) is made more difficult. With another known fastening the rubber ring is pressed into the assembly part at its large circumference. This sleeve may be arranged in the rubber ring with play so that it may be telescoped up to the abutment of its foot flange on a collar of the rubber ring. Since also the screw may be displaced with respect to the sleeve there results as a whole an enlarged ability to telescope which favours the application on a carrier component. However the circumferential pressing does not ensure any particularly safe pre-assembly in the assembly part. With yet another fastening, the foot flange engages behind several undercuts, which in a cover part are preferably injected from plastic. The manufacture requires complicated injection tools. Furthermore the undercuts on pressing in the foot flange may shear off so that the transport securement is not ensured. From EP 0 272 642 A a fastener assembly adapted for use in connection with a first and second apertured workpiece has become known, wherein the fastener assembly comprises a fastener, a washer and a rubber grommet. The fastener has a head and a shank, and the shank includes an upper shank portion and a lower threaded portion and a pair of wings spaced between the upper unthreaded shank portion and lower threaded portion. The washer and rubber grommet being telescopically associated with the fastener. The sleeve has a narrowed inner portion which allows the unusable retaining of the fastener on the sleeve. The grommet has a radial flange portion which is located between the fastener head and the first workpiece portion. The grommet is of elastic material, and has a cylindrical portion which upon mounting on the sleeve protrudes beyond the flared end of the sleeve. Proceeding from this it is the object of the invention to provide a fastening arrangement to fasten an assembly part to a carrier part, which improves the safety of an unlosable pre-assembly, favours an assembly without the protrusion of the screw ends out of the assembly part and may be applied in the case of decoupling a hard screw. The object is achieved by the features of claim 1. Advantageous embodiments of the fastening assembly are specified in the dependent claims. The fastening assembly according to the invention has at least one fastening screw which comprises a screw head with engaging surfaces for a tool, a screw shank, at least one radial projection on the screw shank at a distance from the screw head and a thread at least at the distance of the radial projection from the screw head. The radial projection may be formed by the upper end of the thread. Preferably, however at least one special projection is provided. With this it may be the case of a single projection which extends only about a part or about the whole circumference of the shank, or several radial projections which are distributed over the circumference of the screw shank, in particular in the form of a knurling. Furthermore the fastening assembly has a sleeve with an inner diameter which corresponds at least to the outer diameter of the radial projection and of the thread, which preferably at the upper end comprises a projection radially inwards with an inner diameter smaller than the outer diameter of the radial projection, however at least as large as the outer diameter of the screw shank between the screw head and the radial projection. This narrow location may be formed by at least one radially inwardly protruding projection of the sleeve. Furthermore the sleeve comprises at the upper end a head flange and at the lower end a foot flange preferably with a smaller outer diameter than the head flange. Into the sleeve the fastening screw is applied wherein the narrow location is snapped over the radial projection of the fastening screw and is allocated to the screw head of the outer side of the head flange. The applied fastening screw may thus be axially displaced in the sleeve, is however unlosably retained therein by abutment of the radial projection on the radially inward projection of the sleeve. Further there is present a flexible assembly ring whose inner diameter is smaller than the outer diameter of the foot flange and which is arranged between the head flange and foot flange on the sleeve. Preferably, the assembly ring is elastic so that by broadening, sliding over the flange, preferably the foot flange, and subsequent elastic retraction on the sleeve, it can be assembled on the sleeve. Between the assembly ring and the foot flange there may be present a radial play, by which means a compensation of tolerances and heat expansions is obviated. A through-bore in the assembly part has an inner diameter, which is at least as large as the outer diameter of the foot flange so that the sleeve with the inserted fastening screw may be inserted into the through-bore. With this the assembly ring is pre-assembled on the sleeve. The inner diameter of the through-bore is dimensioned such that it radially presses together the assembly ring on insertion and by way of this is clamped in. The through-bore comprises an undercut with an inner diameter so that the assembly ring under radial compression and subsequent expansion is pushed through the undercut and by which the assembly ring is retained in the through bore. The through-bore may have the undercut at the upper end, which may clamp in the assembly ring in an intermediate position. In an adjacent bore section the assembly ring may still be clamped in. The through bore may however have the same inner diameter everywhere so that it clamps in the assembly ring in every possible insertion location. The sleeve is supported with the lower side of the head flange directly over an elastic intermediate position on the upper edge region of the through- bore. In the carrier part there is provided at least one threaded bore into which the thread of the fastening screw is screwed in and on whose edge region there is supported the foot flange of the sleeve. The supporting of the assembly part may either be effected directly or via an elastic intermediate layer. The fastening assembly according to the invention, by way of the radial projection of the fastening screw and the narrow location of the sleeve, the arrangement of the assembly ring between the head flange and the foot flange and the clamping tight and/or the retaining of the assembly ring in the assembly part, favours unlosable pre-assembly. A protrusion of the fastening screw out of the assembly part is avoided since the fastening screw with respect to the sleeve as well as the sleeve with respect to the assembly ring may be telescoped. The fastening assembly is suitable for a hard screw case as well as for an elastically decoupled screwing. Manufacturing and heat tolerances may be compensated for by play between the sleeve and assembly ring. The elements can be easily embodied so that they resist high loadings in particular on account of temperature and aggressive substances, such as for example as occur with motors. Particularities of the head flange and the foot flange from the dependent claims may in as far as is possible, be transmitted to the collar and the further collar of the fastening screw. The invention is hereinafter described in more detail by way of the accompanying drawings of several embodiment examples. In the drawings there are shown: Fig. 1 an assembly ring in the plan view (a) and a fastening to the assembly ring in the longitudinal section (b); Fig. 2 an assembly ring with end sections for supporting a sleeve in an intermediate position in the plan view (a) and a fastening to die assembly ring in the intermediate position in the longitudinal section (b); Fig. 3 an assembly ring with end regions of increased flexibility in the plan view (a) and a fastening to the assembly ring in an intermediate position in die longitudinal section (b); Fig. 4 an assembly ring with inner projecting contact regions on two ends in the plan view (a) and in a fastening in an intermediate position in a longitudinal section (b); Fig. 5 a metallic assembly ring in the plan view (a) and in a fastening in longitudinal section (b); In the Figs. 2 to 5 for reasons of simplification the carrier part is left out. In all drawings components corresponding to one another are indicated with the same reference numerals. The details to a reference numeral apply for all embodiment examples with the same reference numeral. The fastening according to Fig. 1 has a fastening screw 10, a sleeve 20, an assembly ring 30, an assembly part 40 and a carrier part 50. The fastening screw 10 has a head 11 which at the lower side has a radially projecting collar 12. From the screw head 11 there proceeds a screw shank 13 which comprises a knurling 14 which is at a distance to the screw head and which extends over the whole circumference. Up to the knurling 14 the screw shank 13 is formed smoothly cylindrical. The outer diameter of the knurling 14 which is taken on a circle laid by the outer ends of the knurling is larger than the smooth cylindrical region of the screw shank 13. On the side of the knurling 14 distant to the screw head 11 the screw shank 13 carries a thread 15 whose outer diameter is somewhat smaller than the outer diameter of the knurling 14. At the lower end the fastening screw 10 has a cylindrical introduction peg 16, whose outer diameter again is smaller than that of the thread 15. The screw 10 is preferably manufactured from a metallic material wherein in particular the knurling 14 and the thread 15 may be rolled. The sleeve 20 has a smooth cylindrical section 21, whose inner diameter somewhat exceeds the outer diameter of the knurling 14 so that a displacement of the fastening screw 10 in the sleeve 20 is possible without further ado. At the upper end of the smooth cylindrical section 21 the sleeve 20 on the inside has a narrow location in the form of a circumferential necking 22. In the longitudinal section the necking 22 is recognizable as a slightly bulged contour on the inner side of the sleeve 20. Its inner diameter, i.e. the diameter at the location of its smallest cross section, is smaller than the outer diameter of the knurling 14, but somewhat larger than the outer diameter of the smooth-cylindrical region of the screw shank 13. Preferably it is also somewhat larger than the outer diameter of the thread 15 so that this is not damaged on passage. In the region of the necking 22 and the knurling 14 there is practically no play present between the sleeve 20 and the fastening screw 10 so that the screw 10 can be tilted with respect to the sleeve 20 only negligibly. At the upper end the sleeve has a radially outwardly projecting head flange 23 and at the lower end it comprises a radially outwardly projecting foot flange 24. The outer diameter of the head flange 23 is larger than the outer diameter of the foot flange 24. The sleeve 20 is preferably likewise manufactured of a metallic material, wherein the necking 22 as well as the head flange 24 may be manufactured by a shaping procedure. The latter at the same time may be manufactured by two beading procedures in opposite directions, by which means there results a doubling of the wall thickness. The sleeve 20 may however also be manufactured by swarf-producing machining, e. g. by turning. The assembly ring 30 is formed smooth-cylindrically with bevelings 31, 32 at the upper and lower end. On its side it comprises a longitudinal slot 33 whose width slightly reduces towards its centre. The longitudinal slot with respect to its plane of cross section through its centre 34 is formed symmetrically. Its inner diameter somewhat exceeds the outer diameter of the middle section 21 of the sleeve 20, but is somewhat smaller than the outer diameter of the foot flange 24. The assembly ring 30 is elastic. For the application with motors it may be designed resistant to oil and heating. It may be manufactured of an elastic material for example of a thermoplastic plastic, of an elastomer or thermoplastic elastomer. Basically it may consist of metal. The assembly part 40 has a through-bore 41, whose inner diameter is somewhat larger than the outer diameter of the foot flange 24, but smaller than the outer diameter of the assembly ring 30 in the untensioned condition. Above, the through-bore 41 has an undercut 42 with an even smaller inner diameter. This is however so large that the foot flange 24 may be guided through, that on the other hand the head flange 23 does not fit through, but considerably overlaps the upper edge region of the through-bore 41. The inner diameter of the undercut 42 and the outer diameter of the assembly ring 30 are dimensioned such that the assembly ring on passing through is maximally pressed together so far radially that it bears on the outer side of the sleeve 20 or the two ends of the assembly ring 30 abut against one another. The assembly part 40 may in particular consist of metal or of a plastic. The assembly part 40 and the carrier part 50 abut against one another with plane sides. The carrier part 50 has a threaded bore 51 which accommodates the thread of the fastening screw 10. The foot flange 24 may be supported on the upper edge region of the threaded bore 51. The length of the sleeve 20 and the through-bore 41 are matched to one another such that with a resting foot flange 24 the head flange 23 rests on the upper edge region of the through-bore 41 and the assembly part 40 is pressed between the head flange 23 and the carrier part 50 in a controlled manner. This fastening is pre-mounted in that firstly the fastening screw 10 is pressed into the upper end of the sleeve 20 until the necking 22 snaps behind the knurling 14. Furthermore with the pre-assembly the assembly ring 30 is widened until is fits over the foot flange 24 of the sleeve 20. Then it is pushed over the section 21 and springs together elastically. On account of its symmetry it need not be directed with certain ends above and below. This unit may then be pre-mounted with the assembly part 40 in that the sleeve 20 is inserted into the through-bore 41 and the assembly ring seated thereon is pressed in. If the assembly ring 30 has passed the undercut 42 it is untensioned somewhat. The undercut 42 and the remaining clamping then prevent the assembly ring 30 from exiting upwards out of the through-bore. On the other hand the head flange 23 prevents the sleeve 20 from falling out downwards out of the through bore 41. The pre-assembly is thus securely protected from an unintentional falling apart even when the assembly part 40 with the screw head 11 is transported downwards. With the assembly of the assembly part 40 on the carrier part 50, the fastening screw 10 may telescope up to the abutment of the knurling 14 on the necking 22 and the sleeve 20 up to the abutment of the foot flange 24 on the assembly ring. On applying the assembly part 40 onto the carrier part 50 the lower end 16 of the fastening screw 10 may recede in the through-bore 41. This is particularly advantageous when the threaded bores 51 by displacement of the assembly part 40 must be "searched" on the carrier part 50 until the fastening screws with the introduction pegs 16 fall into the threaded bores 51, in particular when the assembly part 40 at several locations must be fixed in this manner. Finally the fastening screw 10 is screwed into the carrier part 50 until its collar 12 exerts a sufficient clamping force onto the head flange 23 in order to tension the sleeve 20 with the carrier part 50 and the assembly part 40, between the head flange 23 and carrier part 50. The play between the sleeve 20 and the assembly ring 30 ensures the compensation of manufacturing tolerances and heat expansions. A disadvantage of the previously mentioned play is however that the sleeve 20 with a telescoping may tilt in the assembly ring 30 and as a result of this the position of the screw head 11 is not exactly determined. In an automatic screw station it is therefore no longer ensured that the tool finds the screw head. Fig. 2 relates to a solution of this problem. With this solution the assembly ring 30 above and below in each case has a smooth-cylindrical end section 34, 35 with a reduced diameter, wherein however the inner diameter of the assembly ring 30 is constant everywhere. In the shown intermediate position the assembly ring 30 is exactly snapped with its beveling 31 behind the undercut 42 of the through-bore 41 of the assembly part 40. The assembly ring is still pressed together somewhat so that it is retained in this position by a remaining clamping. With this the upper end section 34 above protrudes somewhat beyond the assembly part 40. The head flange 23 of the sleeve 20 is supported on the upper end section 34. As a result of this the fastening screw 10, until its knurling 14 reaches the necking, may be slid somewhat higher than if the head flange 23 is seated on the upper side of the assembly part 40. As a result of this the introduction peg 16 of the fastening screw 10 may be completely pushed into the through-bore without the head flange 23 being lifted from its support on the upper end section 34 of the assembly sleeve 30. For this reason the sleeve 20 does not tilt and the screw head 11 is retained in a position which may be securely controlled also by an automatic screwing tool. On screwing, the assembly ring 30 is completely pressed into the assembly part. The above fastening however only functions when it is directed more or less vertically before the screwing. Otherwise the sleeve 20 may tilt in the assembly ring 30. For differing applications, in particular the horizontal screwing case, there is the embodiment according to Fig. 3. With this embodiment the assembly ring 30 above and below in each case has an axial circumferential slot 36, 37. Furthermore the assembly ring 30 on the outside at half the height has a circumferential annular groove 38. On the outside the assembly ring is dimensioned such that with a bending together of the "hook barb" defined by the slots 36, 37 and the groove 38 in the two end regions, it can be fixed in the through-bore 41. With this the annular groove 38 may just accommodate the undercut 42 in order to secure the assembly ring 30 in an intermediate position. The inner diameter of the assembly ring 30 is selected such that the sleeve 20 may be guided therein in a manner free of play and with a horizontal alignment does not tilt. As a result of this also in a horizontal screwing case the locating of the screw head 11 with a screwing tool is simplified. If the screwing tool has located the screw head 11, the assembly ring 30 is completely pressed into the through-bore 41 on screwing in the fastening screw 10. With the above embodiment example the pressing in of the assembly ring 30 may be made more difficult by the reduced flexibility in the middle region, where a full cross section is present. Fig. 4 shows an embodiment which is suitable for a horizontal screwing case in which the pressing in of the assembly ring 30 is favoured by way of an increased flexibility. For this the assembly ring 30 at the upper and lower end in each case has inwardly projecting contact regions 39, 39'. The inner diameter of the contact regions corresponds roughly to the outer diameter of the section 21 of the sleeve 20 so that a displacement of the two parts to one another is possible, but not a tilting. The inner diameter of the assembly part between the contact surfaces 39, 39' is on the other hand larger than the outer diameter of the section 21. The lower slant 32 favours the leading through of the lower contact region 39' through the undercut 42 of the assembly part 40. With an advancing pressing in, the assembly ring 30 deflects radially inwards between the contact regions 39, 39' until its annular groove 38 accommodates the undercut 42. Then the sleeve 20 is in turn supported so high that the fastening screw 10 with its introduction peg 16 with or without lifting the sleeve 20 can be engaged into the through-bore 41. A pivoting of the sleeve 20 with respect to the assembly ring 30 is prevented by the contact regions 39, 39' and by way of this the screwing is favoured. On screwing in, the assembly ring 30 again is completely pressed into the through-bore 41, until the slant 31 is arranged behind the undercut 42. The Fig. 5 shows an embodiment form with an assembly ring 30 preferably of spring steel. The assembly ring 30 is formed barrel-shaped and likewise comprises a slot 33. It is manufactured in that a tape material is drawn through a matrix and subsequently rolled to a ring. This assembly ring 30 acts similarly to that in Fig. 4, since its concave inner contour at the upper and lower end forms supports 39, 39'. Such an assembly ring 30 may also consist of plastic.

Claims: A fastening arrangement securing an assembly part to a carrier part, said fastening arrangement including: (i) at least one fastening screw (10) including a screw head (11) with engaging surfaces for interacting with a tool, a screw shank (13), at least one radial projection (14) on the screw shank (13) at a spaced distance form the screw head (11) and a thread (15) located between the radial projection (14) and an end of the shank remote from the screw head (11), (ii) a sleeve (20) having an inner diameter which corresponds at least to an outer diameter of the radial projection (14) and of the thread, the sleeve including a radially inward projection (22) formed with an inner diameter smaller than the diameter of the radial projection (14) but at least as large as the outer diameter of the screw shank (13) between the screw head (11) and the radial projection (14), an upper end of the sleeve comprises a head flange (23) and at a lower end of the sleeve includes a radial enlargement the fastening screw (10) being inserted into the sleeve such that the radially inward projection (22) is snapped over the radial projection (14) of the fastening screw (10) to locate the screw head (11) adjacent an outer side of the head flange (23), (iii) a flexible annular element having an inner diameter smaller than the outer diameter of each of the head flange (23) and the foot flange (24), the annular element being mounted on the sleeve (20) , (iv) the assembly part (40) including a through-bore (41) having an inner diameter at least as large as the outer diameter of the foot flange (24) and into which the sleeve (20) is inserted, wherein the inner diameter of the through-bore (41) is dimensioned such that the annular element has portions radially pressed therein in clamping engagement with the through-bore (41), and thereby the assembly ring is retained in the through-bore (41), and (v) the carrier part (50) including a threaded bore (51) receiving the thread (15) of the fastening screw (10) . characterized in that the radial enlargement is formed by a foot flange (24) and the carrier part (50) has an edge region to support the foot flange (24) of the sleeve (20), the annular element is an assembly ring (30) which is arranged between the head flange (23) and the foot flange (24) the lower side of the head flange (23) is supported on an upper edge region of the through-bore (41) and the through-bore (41) comprises an undercut (42) with an inner diameter enabling the assembly ring (30) under radial compression and subsequent expansion to be pushed through the undercut (42). A fastening arrangement according to claim 1,wherein the radial projection (14) is formed separately from the thread (15). A fastening arrangement according to claim 2, wherein the radial projection comprises a knurling on the screw shank (13). A fastening arrangement according to one of the claims 1 to 3, wherein the screw shank (13) at its end opposite the screw head (10) comprises a cylindrical introduction peg (16) with a smaller outer diameter than the thread (15). A fastening arrangement according to one of the claims 1 to 4, wherein the screw head (11) at the lower end has a radially projecting collar (12). A fastening arrangement according to one of the claims 1 to 5, wherein the distance of the lower side of the head flange (23) from the lower side of the foot flange (24) is somewhat smaller than the length of the through-bore (41) of the assembly part (40) in order to effect a pressing of the assembly part (40) between the head flange (23) and the carrier part (50). A fastening arrangement according to one of the claims 1 to 6, wherein the distance of the lower side of the head flange (23) from the lower side of the foot flange (24) is somewhat larger than the length of the through-bore (41) and between the head flange (23) and the assembly part (40) there is arranged an elastic intermediate position in order to effect a pressing of the assembly part (40) between the intermediate position and the carrier part (50). A fastening arrangement according to one of the claims 1 to 7, wherein the assembly ring (30) is shorter than the distance between the head flange (23) and the foot flange (24) and the sleeve (20) is displaceably arranged in the assembly ring (30). A fastening arrangement according to claim 8, wherein the fastening screw (10), sleeve (20), assembly ring (30) and through-bore (41) are dimensioned such that with the radial projection (14) bearing on the radial projection (22) snapped thereover and the foot flange (24) bearing on the assembly ring (30) the fastening screw (10) does not protrude beyond the through-bore (41). A fastening arrangement according to one of the claims 1 to 9, wherein the sleeve (20) is arranged in the assembly ring (30) with slight play. A fastening arrangement according to one of the claims 1 to 10, wherein the assembly ring (30) comprises a longitudinal slot (32). A fastening arrangement according to one of claims 1 to 11, wherein the assembly ring with respect to a centre cross sectional plane is symmetrical. A fastening arrangement according to one of the claims 1 to 12, wherein the assembly ring (30) is elastic. A fastening arrangement according to one of claims 1 to 13, wherein the assembly ring (30) is of plastic, elastomer and/or metal. A fastening arrangement according to one of claims 1 to 14, wherein the assembly ring (30) has an end section (34, 35) which in an intermediate position of the assembly ring (30) protrudes above out of the through-bore (41) and on which the head flange (23) is supported, wherein the fastening screw (10), sleeve (20) assembly ring (30) and through-passage (41) are dimensioned such that the fastening screw (10), with the bearing of the radial projection (14) on the radial projection (22) snapped thereover, does not protrude beyond the lower end of the through-bore (41). A fastening arrangement according to one of the claims 1 to 15, wherein the assembly ring (30) thereof comprises axial circumferential slots (36, 37) proceeding from both end faces which at both ends delimit regions of higher flexibility which permit a clamping in the through-bore (41). A fastening arrangement according to one of the claims 1 to 16, wherein the inner diameter of the assembly ring (30) is roughly equal to the outer diameter of the sleeve (20) between the head flange (23) and the foot flange (24). A fastening arrangement according to one of the claims 1 to 17, wherein the assembly ring (30) at the upper and lower end comprises radially inwardly projecting contact regions (39, 39') whose inner diameter corresponds roughly to the outer diameter of the sleeve (20) between the flanges (23, 24), whereby the assembly ring (30) is supported on the sleeve (20) between the head flange (23) and the foot flange (24) and between which the assembly ring can be radially compressed. A fastening arrangement according to one of the claims 1 to 18, wherein the assembly ring (30) externally comprises an annular groove (38). A fastening arrangement according to one of the claims 1 to 18 and 19, wherein the assembly ring (30) in an intermediate position can be fixed with the annular groove (38) on the undercut (42), whereby the assembly ring (30) partly protrudes beyond the upper end of the through-bore (41) and keeps the head flange (23) at a distance from the assembly part (40).

Inventors: KIRCKHOFF PETER, SPICKENHEIER KLAUS, SZEZUKOWSKI ADI, KIRCKHOFF, PETER, SPICKENHEIER, KLAUS, SZEZUKOWSKI, ADI
Applicants: ITW AUTOMOTIVE PROD GMBH & CO, ITW AUTOMOTIVE PRODUCTS GMBH & CO. KG
Application year: 1999
Main classification: F02F1
IPC codes: F16B41, F02M35, F02F7