Abstract:
A coupling device for elastic interconnection of, e.g., arms ( 66 ) which are linked to a frame ( 60 ) of the vehicle. The coupling device ( 92 ) substantially comprises two annular, conical portions ( 112, 114 ) of a rubber elastic material and an axle ( 94 ). A radially internal side of these annular material portions ( 112, 114 ) abuts against contact portions ( 98, 100 ) at the ends of the axle ( 94 ). The coupling device ( 92 ) further comprises two axially opposite rings ( 124, 126 ) which are arranged to abut against respective external sides of the annular material portions ( 112, 114 ). The axle ( 94 ) and the rings ( 124, 126 ) have attachment areas ( 96, 121  and  123  respectively), via which they can be attached to the wheel axle housing ( 82 ) and the frame ( 60 ) respectively. The attachment area ( 96 ) for the axle ( 94 ) is located between the first contact portions ( 98, 100 ).

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a coupling device for elastic interconnection of a first and a second object. 
   A coupling device of this type is used, e.g., in vehicles in connection with mounting a wheel axle housing in a chassis of the vehicle, as disclosed, e.g., in U.S. Pat. No. 5,649,719. 
   If the coupling device&#39;s first contact device is securely connected to a central portion of the wheel axle housing, i.e. the first object, between and under two frame beams of the vehicle, and the second contact device is securely connected to a second end portion of two arms, whose first end portions are each rotatably connected to a frame beam, the object can be achieved that a movement of the wheel axle housing both in the vehicle&#39;s longitudinal direction and in the vehicle&#39;s horizontal transverse direction can substantially be prevented, while a relative movement of the wheel axle housing and the chassis in the height direction during a relative rotation or tilting of the chassis and the wheel axle housing at the linkage between the chassis and the first end portion of the arms, and a rolling of the wheel axle housing relative to the chassis are substantially possible. 
   The counteraction of the movement of the chassis in the vehicle&#39;s longitudinal direction and transverse direction depends on attempts being made hereby to compress portions of the rubber elastic material between the contact portions and on the rubber elastic material exerting substantial resistance against such a compression since it is virtually incompressible. However, the compression is not completely counteracted, since the material has a limited opportunity of escaping laterally at the material&#39;s free surfaces. The tilting is permitted since the rubber elastic portion is hereby mainly influenced only by a shearing stress and does not offer such great resistance against it. 
     FIG. 1  is a perspective view of such a known mounting of a wheel axle housing where a coupling device of the above-mentioned type is employed, with an exploded view of the components, and  FIG. 2  illustrates a longitudinal section through the coupling device. 
   First end portions  6 ,  8  of two arms  2 ,  4  are each connected via respective screws  10  to the longitudinal frame beam  12  of a vehicle. The second end portions of the arms  2 ,  4  converge at and are securely connected to a connecting piece  14 . 
   The connecting piece  14  is located above and in front of a wheel axle housing  16 . To the upper portion of this housing  16 , a bracket  20  with two arms  22 ,  24  is attached by means of screws  18 . 
   The connecting piece  14  and the bracket  20  are interconnected by means of a coupling device  26  of the above-mentioned type by means of screws  27 , with the connecting piece  14  clasping the coupling device  26 . 
   As illustrated in  FIG. 2 , the coupling device  26  comprises a sleeve-shaped device or rubber device  28  which is made of a rubber elastic material, and which has two conical end portions  30 ,  32 , which are interconnected via an axial portion  34 . 
   Through the rubber device  28  there extends a first contact device  36  whose end portions have attachment areas  38 ,  40  extending outwards past each end of the rubber device  28  and provided with holes  42 ,  44  for the screws  27 . A central, extended portion or first contact portion  46  of the first contact device  36  extends radially outwards and is attached to the central portion  34  of the rubber device  28 . 
   Outside the rubber device  28  is mounted a second contact device comprising two annular contact portions or rings  48 ,  50 , each of which abuts against an end portion  30 ,  32  of the rubber device  28 . 
   The coupling device  26  is attached in a bore  52  which is provided in the connecting piece  14 , abutting against a shoulder  54  on one side and against a securing ring  56  on the other side. 
   Since the end portions  38 ,  40  of the first contact device  36  project through and out of the rubber device  28 , taking up space radially, the radial measurement of the conical portions  30 ,  32  of the rubber device  28  is consequently relatively small, with the result that these portions are not capable of appreciably counteracting a movement of the wheel axle housing  16  in the vehicle&#39;s transverse direction. This results in the vehicle having unsatisfactory driving characteristics. 
   Furthermore, the known coupling device is expensive and requires a great deal of space. Moreover, with the known device the wheel axle housing has to be located at a fixed height relative to the chassis when mounting the coupling device, resulting in a time-wasting assembly process. 
   Also U.S. Pat. No. 5,967,668 and U.S. Pat. No. 5,975,760 disclose coupling devices. None of these, however, show a specific arrangement of attachment area, rubber components and contact devices as in the coupling device according to the invention. 
   The object of the invention is to provide a coupling device of the above-mentioned type which is encumbered to a lesser extent by the above-mentioned disadvantages. 
   SUMMARY OF THE INVENTION 
   This object is achieved by a coupling device for elastic interconnection of a first and a second object, comprising 
   a device of a rubber elastic material, with two annular material portions, each of which extends round a longitudinal axis at an axial distance apart and with an inner and an outer, substantially conical side facing away from and towards the longitudinal axis towards respectively, 
   a first contact device which extends axially through the annular material portions and has first contact portions which are arranged to abut against respective inner sides of the material portions, 
   a second contact device with second portions which is arranged to abut against respective outer sides of the material portions, 
   where the first contact device has a first attachment area, whereby it can be attached to one of the objects. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described in greater detail with reference to the drawings. 
       FIGS. 1 and 2  illustrate a known coupling device. 
       FIG. 3  illustrate a first embodiment of a coupling device according to the invention and is a vertical longitudinal section through a vehicle along line III—III in  FIG. 4 . 
       FIG. 4  illustrates a section along line IV—IV in  FIG. 3 , through a coupling device according to the invention and adjacent portions of a vehicle. 
       FIGS. 5–7  illustrate other possible embodiments of the coupling device and are sections corresponding to that indicated by A in  FIG. 4 , and through a second, third and fourth embodiment of the coupling device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   As illustrated in  FIGS. 3 and 4 , to a frame beam  60  of a vehicle there is attached via, e.g., a screw  62 , a first end portion  64  of an arm  66  of a pair of arms for mounting a wheel axle housing  82 . In a similar manner a second arm (not shown) of the pair of arms is attached to an opposite frame beam of the vehicle. From their first end portions  64  the arms extend backwards towards each other, and the second end portions of the arms  66  are securely interconnected via a connecting piece  68  ( FIG. 4 ). This connecting piece  68  is U-shaped, viewed from above, with two legs  70 ,  72  which project backwards and have coaxial through-going bores  74 ,  76 . In the radially internal surface of one bore  74  there is provided a radially inwardly open, circumferential groove  78 , and in the second bore  76  a shoulder  80  is provided in the radially internal surface portion. 
   On the wheel axle housing  82  there is provided an upwardly facing contact portion  84  with two upwardly open threaded holes. A hoop or curved piece  86  is arranged to be secured to the contact portion  84  by means of two screws  88 ,  90 , which are screwed into their respective holes. 
   The arms&#39; connecting piece  68  and the wheel axle housing  82  are interconnected via a coupling device  92 . 
   This coupling device  92  comprises a first contact device  94  in the form of a rotationally symmetrical axle with a longitudinal axis  95 . The contact device  94  comprises a first attachment area which is provided in the form of a central, circumferential, radially outwardly open groove or recess  96 , whose cross sectional shape is adapted to the cross sectional shape of the hoop  86 . This cross sectional shape is preferably radially inwardly tapering, and may be, for example, V-shaped or trapezoidal. 
   The first contact device  94  furthermore has two end portions or first contact portions  98 ,  100 , whose surfaces  102 ,  104  are provided in the form of conical surface portions tapering away from each other, where the longitudinal axes of the cones coincide with the longitudinal axis  95 . 
   The end portions  98 ,  100  may have respective end journals  106 ,  108  projecting away from each other and slightly out of the bores  74 ,  76 . 
   The first contact device  94  abuts against and supports a device  110  of a rubber elastic material. This device  110  comprises two annular material portions or pieces  112 ,  114 , each of which has a radially internal surface  116 ,  118  and a radially external surface  120 ,  122  in the form of coaxial conical surface portions. 
   Radially outside the rubber elastic device  110  there is provided a second contact device  140  comprising second contact portions, or more specifically a first ring  124  and a second ring  126 , each with a radially internal, conical surface  128 ,  130  which is adapted to the external surface  120 ,  122  of the material portions  112 ,  114 , and a radially external, cylindrical surface  132 ,  134 , whose diameter is adapted to the diameter of the bores  74 ,  76  in the legs  70 ,  72  of the connecting piece  68 . 
   The connecting device  92  can be secured to the legs  70 ,  72  by the first ring  124  having a second attachment area  121 , which is arranged to abut against a lock ring  136 , which is inserted in the groove  78  of the leg  70 , and in the same way by the second ring  126  having a second attachment area  123  which is arranged to abut against the shoulder  80  of the leg  72 . The lock ring  136  can be brought into the groove  78  after the coupling device&#39;s rubber elastic material has been elastically compressed in the axial direction towards the right in  FIG. 4 , the coupling device hereby leaning against the shoulder  80 . By this means it is ensured that the annular material portions  112 ,  114  are secured without play between the first and the second contact devices. 
   Alternatively, in the bore  74  screw threads may be provided and the lock ring may have external threads whereby it can be screwed to forceful abutment against the first ring  124  of the second contact device  140 . 
   Furthermore, the coupling device  92  is fixed to the wheel axle housing  82  by the hoop  86  extending in the central groove  96  of the first contact device  94  and being secured thereto by means of the screws  88 ,  90  which are screwed into the threaded holes of the wheel axle housing  82 . 
   Each of the annular material portions or pieces  112 ,  114  may be constructed from several layers of rubber elastic material, between which are mounted corresponding conical reinforcing elements or rings  127  of a strong and rigid material, e.g. metal. The volume of the rubber elastic material which can be forced out or can swell out at free end surfaces of the rubber elastic material can thereby be reduced and the compression resistance of this material can increase, while maintaining the desired pliability of the material in relation to shearing forces. A metal ring corresponding to the reinforcing rings, can mark the radially internal end of the rubber elastic device  110  and be glued to the adjacent rubber elastic material. 
   The coupling device&#39;s components, i.e. the first contact device  94 , the rubber elastic device  110  and the second contact device  140  may be securely interconnected by means of, e.g., an adhesive or the like. 
   The first contact device  94  may be produced with or without end journals  106 ,  108 , since the purpose thereof is to prevent a separation of the wheel axle housing and the connecting piece if the coupling device should fail. 
   It will therefore be understood that the rings  124 ,  126  may extend all the way to the longitudinal axis of the first contact device. Thus the radial extent of the material portions  112 ,  114  may be substantial, with the result that the portion of the connecting piece  68  which prevents a movement of the wheel axle housing in the vehicle&#39;s transverse direction and height direction is substantial, since an escape of rubber elastic material is largely prevented, while a deformation of this material as a result of shearing stresses becomes possible. 
   Even though there should be a need for end journals  106 ,  108 , their diameter will be able to be much smaller than the diameter of the attachment areas  38 ,  40  according to the prior art, since the end journals  106 ,  108  act as an emergency device, which comes into force in the event of the destruction of the rubber elastic material device, and thus only require to be designed to withstand a load which occurs once. 
   It is stated above that the contact device of the coupling device comprises a first contact device or axle with a first attachment area which is provided in the form of a circumferential, radially outwardly open groove, wherein there may be inserted a radially internal portion of a hoop. As illustrated in  FIG. 5 , a corresponding axle  94 ′ may instead have a first attachment area which is provided in the form of a central, radially outwardly projecting bead  144 , where a hoop  86 ′ corresponding to the hoop  86  may have a radially inwardly projecting groove  146 , which can be brought into engagement with the bead  144  in order to secure the axle  94 ′. 
   It will further be appreciated that a corresponding axle  94 ″ may have a cylindrical, central portion  148  and that, instead of a groove or a bead, a corresponding hoop  86 ″ may have a radially inwardly facing cylindrical portion  150 , which can be brought into abutment against the cylindrical portion  148  of the axle  94 ″, as illustrated in  FIG. 6 . If the hoop  86 ″ is sufficiently firmly secured to the axle  94 ″, the object can be achieved that the frictional force which is exerted between these components is so great that a relative movement of the hoop  86 ″ and the axle  94 ″ is prevented. 
   Finally, an axle  94 ′″, as illustrated in  FIG. 7 , may instead by attached to a wheel axle housing by means of, e.g., two screws (not shown) which extend through holes  150 ,  152  in the shaft  94 ′″, and which can be screwed into threaded holes which are provided in the wheel axle housing (not shown). 
   A coupling device is described above for use in connection with a vehicle. It will be appreciated, however, that this coupling device may be employed in connection with any kind of device where there is a need for a corresponding relative movement of two objects, such as any other kind of transport means or other device. Even though it is stated above that the coupling device  92  connects the connecting piece  68  to the wheel axle housing  82 , it will therefore be understood that a coupling device according to the invention is generally arranged to connect two objects with each other in the above-described manner.