Abstract:
The invention relates to a combination of a screw member comprising a screw head, a threaded portion and a shank portion which is arranged between the screw head and the threaded portion and has an external diameter that is smaller than the external diameter of the threaded portion, a washer incorporating a passage opening for the screw member and a sleeve the internal diameter of which is greater than the external diameter of the threaded portion of the screw member, whereby said combination is producible in a simple manner but it is nevertheless ensured that the sleeve and the washer are held securely on the screw member.

Description:
This application is a continuation of International application No. PCT/EP2006/010069 filed on Oct. 19, 2006. 

   RELATED APPLICATION 
   The present disclosure relates to the subject-matter which was disclosed in the international patent application No. PCT/EP2006/010069 dated Oct. 19, 2006. The entire description of this earlier application is incorporated by reference thereto as a constituent part of the present description (“incorporation by reference”). 
   FIELD OF DISCLOSURE 
   The present invention relates to a combination of a screw member comprising a screw head, a threaded portion and a shank portion which is arranged between the screw head and the threaded portion and has an external diameter that is smaller than the external diameter of the threaded portion, 
   a washer incorporating a passage opening for the screw member and a sleeve the internal diameter of which is greater than the external diameter of the threaded portion of the screw member. 
   BACKGROUND 
   Such a combination is known from DE 199 24 502 C2. In this known combination, the sleeve is fixed to the washer by an adhered, welded or soldered joint. The washer and/or the sleeve are slit so that the sleeve and/or the washer expand when slipping the narrow section formed by the washer over the threaded portion of the screw member and then snap back again after the narrow section has been pushed completely over the threaded portion. 
   The washer and the sleeve are held captive on the screw member once they have snapped back. 
   A further combination of a screw member and a washer together with a sleeve which are held captive on the screw member is known from DE 195 10 349 A1. In this combination, the washer comprises a deep-drawn opening having a collar which is surrounded by the sleeve in clamping manner. For the purposes of clamping the collar of the washer, the inside of the sleeve must be provided with a chamfer at the screw head end thereof. The retention of the sleeve on the washer, which is only effected by the clamping effect produced by the collar projecting into the sleeve, is not particularly secure. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is to provide a combination of the type mentioned hereinabove which is producible in a simple manner but which nevertheless ensures that the sleeve and the washer are held securely on the screw member. 
   In accordance with the invention, this object is achieved in the case of a combination comprising the features indicated in the preamble of claim  1  in that the passage opening in the washer comprises a first region having a diameter which is greater than the external diameter of the shank portion of the screw member and smaller than the external diameter of the threaded portion of the screw member, and a second region having a diameter which is greater than the external diameter of the threaded portion of the screw member, and in that the sleeve and the washer are connected to one another in such a manner that the sleeve and the washer are held captive on the screw member. 
   The concept underlying the present invention is that of feeding the threaded portion of the screw member through the second region of the passage opening in the washer having a diameter which is greater than the external diameter of the threaded portion of the screw member until the shank portion of the screw member enters the passage opening and then transferring the shank portion of the screw member from the second region of the passage opening into the first region of the passage opening through which the threaded portion of the screw member having a diameter greater than the diameter of the first region of the passage opening can then no longer be moved in the reverse direction. In consequence, the washer is held captive on the screw member in a simple manner. 
   For its part, the sleeve is then held captive on the screw member by virtue of it being connected to the washer. 
   Hereby, the connection between the sleeve and the washer can be effected directly or indirectly with the help of an additional component which is connected to the sleeve on the one hand and to the washer on the other. 
   Since the threaded portion of the screw member can be moved through the second region of the passage opening in the washer, it is not necessary to use a slit washer and/or a slit sleeve; rathermore, a slot-free sleeve and a slot-free washer can be used in the combination in accordance with the invention. 
   In a preferred embodiment of the invention, provision is made for the first region and the second region of the passage opening to be connected to one another in such a way that the screw member can be transferred from the second region into the first region of the passage opening when the shank portion of the screw member extends through the passage opening in the washer. 
   In the assembled state of the combination, the shank portion of the screw member preferably extends through the first region of the passage opening in the washer. 
   In principle, the first region and the second region of the passage opening may be provided in the washer in such a manner that they do not overlap and they may be connected to one another by means of a channel arranged therebetween. 
   In a preferred embodiment of the invention however, provision is made for the first region and the second region of the passage opening in the washer to partly overlap one another. Due to this overlapping, the overall proportion of the washer occupied by the passage opening in the washer is reduced so that the effective surface area of the washer by means of which the washer rests against the screw head is kept as large as possible. 
   The centre of the first region of the passage opening in the washer is preferably arranged substantially centrally of the washer. The effect is thereby achieved that the screw member is substantially coaxial with the washer in the assembled state of the combination. 
   By contrast however, the centre of the second region of the passage opening in the washer is preferably displaced outwardly relative to the centre of the first region of the passage opening in the washer, i.e. it is displaced towards the outer edge of the washer. 
   In one embodiment of the combination in accordance with the invention, provision is made for the edge of the first region of the passage opening in the washer and the edge of the second region of the passage opening in the washer to merge into one another at a transitional zone, whereby—as seen from the centre of the first region of the passage opening—the edge of the transitional zone is curved convexly. In this embodiment of the invention, this thereby results in a substantially keyhole shaped passage opening. 
   As an alternative thereto, provision is made in a second embodiment of the invention for the edge of the first region of the passage opening in the washer and the edge of the second region of the passage opening in the washer to merge into one another at a transitional zone, whereby the edge of the transitionally zone runs substantially tangentially to the edge of the first region of the passage opening and/or substantially tangential to the edge of the second region of the passage opening. In this embodiment, the threaded portion of the screw member can be fed through the second region of the passage opening in the washer in a particularly simple manner. 
   In order to enable the sleeve to be connected indirectly to the washer, provision may be made for the combination to comprise at least one ring-shaped element which is fixed to the washer and has a seating for the screw head end of the sleeve. 
   The ring-shaped element may be in the form of a resilient element in order to decouple the combination from vibrations occurring in the components that are to be connected together by the combination. 
   The ring-shaped element may, in particular, comprise an elastomer material. 
   The screw head end of the sleeve can be held on the ring-shaped element in positive and/or force-locking manner. 
   In particular, provision may be made for the screw head end of the sleeve to be latched to the ring-shaped element. 
   In principle, the ring-shaped element can be fixed to the washer in an arbitrary manner. 
   A particularly durable and easy to produce connection of the ring-shaped element to the washer results if the ring-shaped element is adhered to the washer. 
   Furthermore, the present invention relates to a method of producing a combination of a screw member comprising a screw head, a threaded portion and a shank portion which is arranged between the screw head and the threaded portion and has an external diameter that is smaller than the external diameter of the threaded portion, 
   a washer incorporating a passage opening for the screw member and a sleeve the internal diameter of which is greater than the external diameter of the threaded portion of the screw member. 
   A further object of the present invention is to provide a method of producing such a combination which is simple to effect and leads to the sleeve and the washer being securely retained together as well as to the screw member. 
   In accordance with the invention, this object is achieved by a method which comprises the following method steps:
         providing a washer incorporating a passage opening which includes a first region having a diameter that is greater than the external diameter of the shank portion of the screw member and is smaller than the external diameter of the threaded portion of the screw member, and a second region having a diameter which is greater than the external diameter of the threaded portion of the screw member;   inserting the screw member into the passage opening in the washer in such a manner that the threaded portion of the screw member moves through the second region of the passage opening in the washer until the shank portion of the screw member extends through the passage opening;   transferring the shank portion of the screw member from the second region of the passage opening in the washer into the first region of the passage opening in the washer;   inserting the screw member into the sleeve;   connecting the sleeve to the washer in such a manner that the sleeve and the washer are held captive on the screw member.       

   Furthermore, a preferred embodiment of this method comprises the following:
         fixing a ring-shaped element to the washer;   connecting the sleeve to the ring-shaped element in such a manner that the sleeve, the ring-shaped element and the washer are held captive on the screw member.       

   Hereby, the ring-shaped element can be fixed to the washer before or after the insertion of the screw member into the passage opening in the washer, for example, by means of an adhesive. 
   Further features and advantages of the invention form the subject matter of the following description and the graphical illustration of exemplary embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a schematic sectional view through an assembly consisting of a first component and a second component which are fixed together by means of a screw member having a washer and a sleeve that are held captive on the screw member and are also decoupled from vibration by means of elastomer elements; 
       FIG. 2  a schematic longitudinal sectional view through the screw member comprising a washer, a sleeve and an elastomer element depicted in  FIG. 1 ; 
       FIG. 3  a plan view from above of the washer depicted in  FIGS. 1 and 2 ; 
       FIG. 4  a schematic perspective illustration of the screw member inserted into the washer and the sleeve; 
       FIG. 5  a plan view from above of a second embodiment of a washer having a differently formed passage opening; and 
       FIG. 6  a schematic perspective illustration of the process of inserting the screw member into the washer. 
   

   Similar or functionally equivalent elements are designated by the same reference symbols in each of the Figures. 
   DETAILED DESCRIPTION OF THE INVENTION 
   An assembly having the general reference  100  which is illustrated in sectional manner in  FIG. 1  comprises a first component  102  having a substantially cylindrical passage opening  104 , a second component  106  having a threaded blind hole  108 , a ring-shaped elastomer sealing element  114  comprising an upper sealing lip  116  and lower sealing lips  118  arranged between a lower surface  110  of the first component  102  and an upper surface  112  of the second component  106  and also a flange  120  projecting radially into the interior of the elastomer sealing element  114 , and a combination  122  consisting of a screw member  124 , a washer  126  held captive on the screw member  124 , a hollow cylindrical sleeve  128  held captive on the screw member  124  and a ring-shaped element  130  which surrounds the screw-head-end portion of the sleeve  128  in ring-like manner and is fixed to the washer  126  by means of an adhesive for example. 
   The screw member  124  comprises a screw head  132  which may be in the form of a hexagonal screw head for example, a threaded portion  134  having an external diameter D, a shank portion  136  which is arranged between the threaded portion  134  and the screw head  132  and has an external diameter d that is smaller than the external diameter D of the threaded portion  134 , and an end portion  138  which adjoins the end of the threaded portion  134  remote from the screw head  132  and the external diameter of which is smaller than the external diameter D of the threaded portion  134  and smaller than the external diameter d of the shank portion  134  of the screw member  124 . 
   As can best be seen from  FIGS. 1 and 2 , the sleeve  128  is of hollow cylindrical shape and it is provided at the screw head end thereof with a screw-head-end flange  140  that projects outwardly in the radial direction and, at the end thereof remote from the screw head  132 , it is provided with a threaded-portion flange  142  that projects outwardly in the radial direction. 
   As can best be seen from  FIG. 3 , the washer  126  is in the form of a substantially flat, circular disc of external diameter A which is provided with a passage opening  144  that comprises a first circular region  146  the central point or centre  148  of which coincides with the central axis  150  of the washer  126  and a second circular region  152  the central point or centre  154  of which is displaced outwardly by the distance A with respect to the centre  148  in a direction aligned radially relative to the central axis  150 . 
   The first region  146  of the passage opening  144  arranged centrally of the washer  126  has a diameter d′ which is greater than the external diameter d of the shank portion  136  of the screw member  124  and is smaller than the external diameter D of the threaded portion  134  of the screw member  124 . 
   The second region  152  of the passage opening  144  arranged off-centre of the washer  126  has a diameter D′ which is greater than the external diameter D of the threaded portion  134  of the screw member  124 . 
   As can be seen from  FIG. 3 , the first region  146  and the second region  152  of the passage opening  144  overlap in the region  156  marked by shading. 
   The circular arc shaped edge  174  of the first region  146  of the passage opening  144  and the circular arc shaped edge  176  of the second region  152  of the passage opening  144  merge into one another at two transitional zones  157 , whereby the edges  172  of the transitional zones  157 —as seen from the centre  148  of the first region  146  of the passage opening  144 —are convexly curved (with a radius of curvature R 1 ). 
   The sleeve  128 , the washer  126  and the screw member  124  are preferably formed from a metallic material, and in particular from a steel material. 
   The ring-shaped element  130  is preferably formed from a resilient material, for example, from an elastomer material. 
   As can best be seen from  FIG. 1 , the ring-shaped element  130  has an internal contact surface  158  for application to the exterior  160  of the sleeve  128 , a flat washer-side contact surface  162  for application to the lower surface  164  of the washer  126  and a component contact surface  166  remote from the washer  126  and the screw head  132  for application to an upper surface  169  of the first component  102 . 
   The ring-shaped element  130  is coaxial with the washer  126  and the washer-side contact surface  162  thereof is adhered to the lower surface  164  of the washer  126 . 
   The inner surface of the ring-shaped element  130  is chamfered at the upper washer-end part thereof so that the inner space surrounded by the ring-shaped element  130  flares, conically for example, towards the washer-side contact surface  162 , and the upper washer-end section of this inner space forms a seating  168  for the screw-head-end flange  140  of the sleeve  128 . The section of the inner wall of the ring-shaped element  130  running at an angle relative to the central axis of the ring-shaped element  130  forms an undercut which retains the screw-head-end flange  140  of the sleeve  128  in the seating  168  when the screw-head-end flange  140  is accommodated in the seating  168 . 
   One proceeds as follows in order to produce the combination  122  consisting of the screw member  124 , the washer  126  held captive on the screw member  124 , the sleeve  128  held captive on the screw member  124  and the ring-shaped element  130 : 
   Firstly, the ring-shaped element  130  is adhered to the washer  126 . 
   The interior of the ring-shaped element  130  is dimensioned such that it is possible to insert the threaded portion  134  of the screw member  124  forwardly through the off-centre second region  152  of the washer  126 . 
   The screw member  124  is then inserted into the passage opening  144  in the washer  126  in a manner such that the threaded portion  134  of the screw member  124  moves through the second region  152  of the passage opening  144  in the washer  126  until the shank portion  136  of the screw member  124  enters the passage opening  144 . This is easily possible, since the second region  152  of the passage opening  144  has a diameter D′ which is greater than the external diameter D of the threaded portion  134  of the screw member  124 . 
   Thereafter, the shank portion  136  of the screw member  124  is transferred from the second region  152  of the passage opening  144  in the washer  126  into the first region  146  of the passage opening  144  in the washer  126  by pushing the screw member  124  transversely relative to the longitudinal direction  170  thereof. In consequence, the state illustrated in  FIG. 4  is reached wherein the shank portion  136  of the screw member  124  extends through the first region  146  of the passage opening  144  in the washer  126 . 
   Next, the screw member  124  is inserted into the sleeve  128  the internal diameter D″ of which is greater than the external diameter D of the threaded portion  134  of the screw member  124 . 
   Firstly hereby, the washer  126  together with the ring-shaped element  130  affixed thereto is pushed against the screw head  132  by the sleeve  128 , and subsequently the lower section of the interior of the ring-shaped element  130  remote from the washer  126  is expanded by the screw-head-end flange  140  of the sleeve  128  due to its overcoming of the resilient restoring force of the ring-shaped element  130  so that the screw-head-end flange  140  passes this lower section of the ring-shaped element  130  and enters into the seating  168  of the ring-shaped element  130  where it is restrained by the undercut of the ring-shaped element  130  so that the sleeve  128  is latched to the ring-shaped element  130  and the washer  126 . 
   Moreover, the restored ring-shaped element  130  exerts a contact pressure on the outer surface  160  of the sleeve  128  so that the sleeve  128  is also connected to the ring-shaped element  130  and thus to the washer  126  by virtue of the frictional engagement. 
   Since the ring-shaped element  130  and the seating  168  are aligned coaxially with the central axis  150  of the washer  126 , the sleeve  128  is also held on the washer  126  coaxially relative to the central axis  150  thereof. 
   Furthermore, as the lower end part of the sleeve  128  extends up to the threaded portion  134  of the screw member  124  and the internal diameter D″ of the sleeve  128  is only slightly greater than the external diameter D of the threaded portion  134  of the screw member  124 , the longitudinal direction  170  of the screw member  124  is substantially coaxial with the longitudinal axis of the sleeve  128  and thus the central axis  150  of the washer  126 . 
   Consequently, after the insertion of the screw member  124  into the sleeve  128  and following the engagement of the screw-head-end flange  140  of the sleeve  128  in the ring-shaped element  130 , it is no longer possible to displace the screw member  124  from the central first region  146  of the passage opening  144  in the washer  126  into the off-centre second region  152  of the passage opening  144 . 
   Hence, in this state, the threaded portion  134  of the screw member  124  having the external diameter D can no longer return through the passage opening  144  in the washer  126  since the diameter d′ of the first region  146  of the passage opening  144  is smaller than the external diameter D of the threaded portion  134 . The sleeve  128 , the washer  126  and the ring-shaped element  130  affixed thereto are thus held captive on the screw member  124 . 
   In the installed state of the assembly  100  as is illustrated in  FIG. 1 , the external thread of the threaded portion  134  of the screw member  124  is twisted into the internal thread of the threaded blind hole  108  in the second component  106 . The screw member  124  and the sleeve  128  extend through the passage opening  104  in the first component  102 . 
   The sleeve  128  and the washer  126  are supported on the first component  102  via the resilient ring-shaped element  130  so that the sleeve  128 , the washer  126  and the screw member  124  are vibrationally-decoupled from the first component  102 . 
   Furthermore, due to the flange  120  of the elastomer sealing element  114  arranged between the first component  102  and the second component  106  which laps over the flange  142  at the threaded portion end of the sleeve  128 , there is provided a vibration decoupling means between the two components  102  and  106 . 
   In  FIGS. 5 and 6 , there is illustrated a second embodiment of a combination  122  consisting of a screw member  124 , a sleeve  128  held captive on the screw member  124  and a washer  126  that has a ring-shaped element  130  affixed thereto and is held captive on the screw member  124 , which embodiment differs from the first embodiment described hereinabove only in that the transitional zones  157  whereat the edge  174  of the first region  146  and the edge  176  of the second region  152  of the passage opening  144  merge into one another do not—as seen from the central axis  150  of the washer  126 —have convexly curved edges, but rather, each has an edge  172  which runs tangentially to the edge  174  of the first region  146  of the passage opening  144  and tangentially to the edge  176  of the second region  152  of the passage opening  144  instead. 
   Consequently, in this second embodiment, the passage opening  144  in the washer  126  does not have a keyhole shaped outline as in the first embodiment, but rather, it takes the form of an elongated hole having different radii of curvature at the two ends of the elongated hole instead. 
   In this embodiment too, the threaded portion  134  of the screw member  124  can be passed through the second region  152  of the passage opening  144  and afterwards the screw member  124  can be pushed from the second region  152  into the first region  146  of the passage opening  144  so that the threaded portion  134  of the screw member  124  can no longer return through the passage opening  144 . 
   In all other respects, the second embodiment of the combination of a screw member  124 , a sleeve  128 , a washer  126  and a ring-shaped element  130  illustrated in  FIGS. 5 and 6  agrees as regards the construction, functioning and manner of production thereof with the first embodiment illustrated in  FIGS. 1 to 4  to the above description of which hereinabove reference is, to this extent, made.