Abstract:
An external mirror assembly for a motor vehicle with a base ( 16 ) and an adjustable mirror head ( 12 ) and a pivot and vibration absorption mechanism ( 14 ) on the base ( 16 ) allowing manual adjustment of the mirror head ( 12 ) with respect to the base ( 16 ). The pivot and vibration absorption mechanism ( 14 ) has a ball joint ( 22, 26 ) to enable pivoting and frictionally engaging faces ( 36, 38, 42 ) spaced apart from the ball joint ( 22, 26 ) on the base ( 16 ) and the mirror head ( 12 ) to provide vibration absorption. The respective faces ( 36, 38, 42 ) are part spherical surfaces resiliently urged together by resilient means ( 46 ).

Description:
This application is a National Stage of International Application No. PCT/AU02/01039, filed Aug. 6, 2002, which claims the priority of Australian Patent Application Serial No. PR 6832, filed Aug. 6, 2001. 
   FIELD OF INVENTION 
   This invention relates to a pivot mechanism which is adapted for manual adjustment. 
   Although this specification will be generally discussed in relation to its application to external rear vision mirrors for motor vehicles, it is to be realised that it is useful for a wider range of applications. 
   BACKGROUND OF THE INVENTION 
   An external rear vision mirror for a motor vehicle, must be adjusted for each driver and when adjusted for that driver, it is desirable that the angle of the mirror stays at that set position. There is first of all a requirement that there is some feel or tactile response when a driver is making angle adjustments so that the mirror does not move too quickly when adjustment pressures are placed upon it, but that it moves evenly and non-resiliently. A second requirement is that once in a set position, vibration of the motor vehicle as it is driven along does not change the set position of the mirror. 
   To overcome these problems therefore, it is necessary to have an adjustment system which has some form of frictional load applied to it. 
   It is an object therefore, of this invention to provide an adjustment arrangement particularly adapted for external rear vision mirrors for vehicles but as indicated above the invention is suitable for other applications as well. 
   BRIEF DESCRIPTION OF THE INVENTION 
   In one form therefore, although this may not necessarily be the only or broadest form, the invention is said to reside in a movement controller assembly having a base member and a pivoting member and adapted to control movement of the pivoting member with respect to the base member, the pivot mechanism allowing manual adjustment of the pivot mechanism with respect to the base member, the pivot mechanism having a ball joint to enable pivoting and frictionally engaging faces on the base and pivot mechanisms to provide vibration absorption characterised by the respective faces being part spherical surfaces spaced apart from the ball joint and urged together by resilient means. 
   In an alternative form, the invention is said to reside in a movement control assembly having a base member and a pivoting member and adapted to control movement of the pivoting member with respect to the base member, the base member having a body defining a first internal concave part spherical surface and a plurality of first tongues together defining a second external convex part spherical surface having a radius of curvature less than the radius of curvature of the first part spherical surface, the pivoting member having a plurality of second tongues, faces of the second tongues together defining a third external convex part spherical surface and a fourth internal concave part spherical surface having a radius of curvature less than the third external surface, the second tongues adapted to engage between the first internal surface and the first tongues, and a resilient means adapted to urge the first tongues against the first surface thereby engaging the second tongues between them to provide frictional load against movement of the pivoting member with respect to the base member. 
   Preferably there are four first tongues, four second tongues and four resilient means with one resilient means for each combination of first and second tongues. The resilient means can be by innate resilience of one or more of the tongues or may be by a spring arrangement. 
   The spring arrangement may be a compression spring clip with legs adapted to bear against the body and first tongue respectively and to engage the second tongue therebetween. 
   There may be further provided a yoke acting between the base member and the pivoting member to prevent rotation of the pivoting member with respect to the base member on an axis normal to the base member. 
   There may be further included a bayonet joining mechanism between the base member and the pivoting member. The bayonet joining mechanism may provide a pivot centre for the pivoting member with respect to the base member with the pivot centre being positioned substantially at the centre of curvature of the first internal part spherical surface. 
   In one form, the base member may be adapted to be received in a mirror housing and the pivoting member is adapted to have a mirror support and mirror mounted on it. The base member can be mounted to the mirror housing by screws or alternatively the base member can be mounted into the mirror housing by means of hooks which engage one end of the base member into the mirror housing and a screw or similar arrangement to engage the other end. 
   The bayonet joining mechanism discussed above may include a ball joint. The ball joint may have a hemispherical concave surface on the base member and a hemispherical concave surface on the pivoting member. The pivot centre may be mounted on a radial post extending from the body such that the centre of rotation of the pivot member is substantially at the centre of curvature of the first part spherical surface. 
   In an alternative form, the invention may be said to reside in an external mirror assembly for a motor vehicle, comprising a base and an adjustable mirror head and a pivot and vibration absorption mechanism on the base allowing manual adjustment of the mirror head with respect to the base, the pivot and vibration absorption mechanism having a ball joint to enable pivoting and frictionally engaging faces spaced apart from the ball joint on the base and the mirror head to provide vibration absorption, characterised by the respective faces comprising part spherical surfaces resiliently urged together. 
   The resilient urging of the part spherical surface together may be provided by a spring means. The spring means may be a spring clip. 
   Preferably the spring clips provide frictional engagement of the respective faces to give non-resilient feel for adjustment of the mirror and to prevent vibration of the mirror during motion of the vehicle. 
   There may be further included means to prevent relative rotation of the mirror head with respect to the base about an axis at right angles to the plane of the mirror. Such a means may be a yoke which is fastened to the base and to the pivot mechanism to prevent the relative rotation whilst allowing adjustment as discussed above. 
   The base may be received in a mirror housing. The mirror housing may be pivotally mounted to the side of a vehicle so that the mirror can be folded away to enable parking or in the case of an accident. 
   In a further form the invention may be said to reside in an external mirror assembly for a motor vehicle having a base and a mirror head and adapted to control movement of the mirror head with respect to the base, the base having a body defining a first internal concave part spherical surface and a plurality of first tongues together defining a second external convex part spherical surface having a radius of curvature less than the radius of curvature of the first part spherical surface, mirror head having a plurality of second tongues, faces of the tongues together defining a third external convex part spherical surface and a fourth internal concave part spherical surface having a radius of curvature less than the third external surface, the second tongues adapted to engage between the first internal surface and the first tongues, and a resilient means adapted to urge the first tongues against the first surface thereby engaging the second tongues between them to provide frictional load against movement of the mirror head with respect to the base. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     This then generally describes the invention, but to assist with understanding reference will now be made to the accompanying drawings which show preferred embodiments of the invention. 
     In the drawings: 
       FIG. 1  shows a transverse cross sectional view, along the lines  1 – 1 ′ of  FIGS. 2 and 3 , of a motor vehicle external mirror including the pivot and vibration absorption mechanism of the present invention; 
       FIG. 2  shows an elevation view of the mirror support, with the mirror head removed to show the mechanism inside; 
       FIG. 3  shows a rear view of the mirror head; 
       FIG. 4  shows an alternative embodiment of pivot mechanism according to this invention. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   Now looking more closely at the drawings, and in particular the embodiment shown in  FIGS. 1 to 3  it will be seen that the motor vehicle external mirror includes a mirror mount  2  adapted to be fastened to the side of a vehicle and a rotation mechanism  4  mounted to the mirror mount  2  and to a post  6  extending from a mirror housing  8 . A mirror  10  supported on a mirror support  12  is supported in the mirror housing  8  on a pivot and vibration absorption mechanism generally shown as  14 . 
   The pivot and vibration absorption mechanism  14  has a base  16  which is mounted into the mirror housing  8  by means of screws  18 . The base has a central post  20  with at its upper end a concave recess  22  with a bayonet connection pin  24  in the middle of it. The mirror support  12  has a concave protrusion  26  extending from its rear surface with a slot  28  adapted to receive the bayonet connection pin  24 . The protrusion  26  bearing in the concave recess  22  provides a ball type pivot joint rotatable about a pivot point  23  defined by the concave recess  22  and concave protrusion  26 . The pivot joint enables the mirror support  12  and mirror  10  to be moved so that a driver can adjust the angle of the mirror. 
   On the base  16  is an essentially cup shaped body  30  defining a substantially spherical first concave inner surface  32  with a radius of curvature  33 . Within the cup shaped body  30  and mounted to the body, are four tongues  36  each defining a convex part spherical surface  38  with a radius of curvature  39  which is of a lesser radius of curvature than the concave part spherical inner surface  32  and having essentially the same centre of curvature being the pivot point  23 . 
   The mirror support  12  has a series of four tongues  40  arranged in a circle around the protrusion  26  on the support  12 . Each of the tongues  40  have faces which together define a third external convex part spherical surface  42  with a radius of curvature  43  and a fourth concave part spherical surface  44  with a radius of curvature  45  with the radius of curvature of the fourth surface  44  being less than the radius of curvature of the third surface  42  and the third external convex part spherical surface  42  and the fourth concave part spherical surface  44  having essentially the same centre of curvature being the pivot point  23  when the mirror head is assembled into the mirror support. 
   The tongues  40  fit in between the tongues  36  and the cup shaped body  30  to provide a vibration absorption mechanism. A spring clip  46  engages the tongues  36  and the cup shaped body  30  to draw the two of these together to engage the tongues  40  between them to provide frictional load to be felt during adjustment of the angle of the mirror. The spring clips pass through apertures  48  in the tongues  36  and  50  in the body  30 . 
   A yoke mechanism  52  which is mounted by a hinge to a transverse arm  54  extending from the post  20  as shown in  FIG. 2  has a ball  56  which engages in a slot  58  on the mirror support  12 . This prevents the mirror rotating in an axis normal to the plane of the mirror about the pivot joint while still allowing angular adjustment of the mirror about the pivot point  23 . 
     FIG. 4  shows an alternative embodiment of the invention. 
   In this embodiment a base member  60  is adapted to be received in a mirror support (not shown) and a mirror head (not shown) is mounted onto a pivoting member  68  and the pivoting member is mounted into the base member. 
   The base member  60  has a body  61  with a central post  62  with a concave recess  63  at its upper end with a bayonet connection arrangement  64  with wings  65  within the concave recess  63 . The bayonet connection arrangement  64  is adapted to be received in an aperture  66  in a pivoting member  68  when the parts are assembled The aperture  66  has a transverse slot  67 . The base member has a first concave internal surface  70  with tongues  74  positioned radially inwards from the concave surface  70  and mounted to the base member  60 . Tongues  72  extending from the pivoting member  68  engage between the tongues  74  and concave surface  70  to provide frictional engagement for feel during pivoting of the pivoting member  68  with respect to the base member  60 . A yoke arrangement  80  has a ball joint  82  which engages in slot  84  in the pivoting member  68  and has pivots  86  which engage in hinges  88  on a cross member on the base member  60 . The yoke is used to prevent rotation of the pivoting member  68  with respect to the base member  60  while allowing pivoting or angular adjustment. 
   Spring clips  90  have legs  92 ,  94  which engage the inner surface of the tongues  74  and the outside of the base member  60  respectively to urge the tongues  74  against the concave surface  70  to engage the tongues  72  between them to provide frictional engagement. 
   To assemble the pivoting member  68  onto the base member  60  the following steps are taken. The yoke  80  is fitted onto the hinges  88 . The pivoting member  68  is offered up to the base member with the transverse slot  77  aligned with the wings  65  on the bayonet connection arrangement  64  and the tongues  72  on the pivoting member  68  circumferentially spaced from the tongues  74  on the base member  60 . The pivoting member  68  is then rotated with respect to the base member  60  until the ball joint  82  on the yoke  80  aligns with the slot  84  and the tongues  72  pass between the tongues  74  and the first concave internal surface  70 . At this stage the bayonet connection is made and the pivoting member can be depressed on the region of the slot  84  to engage the ball joint  82  into the slot. Next the spring clips  90  are engaged between the tongues  74  and the outside of the base member  60  to provide the friction necessary to prevent vibration while a motor vehicle is being driven while still allowing mirror adjustment. 
   It will be seen therefore, that by this invention, there is provided a frictional engagement of a pivoting member with respect to a base member to provide feel for adjustment of the mirror and vibration absorption 
   Throughout this specification, various indications have been given as to the scope of the invention, but the invention is not limited to any one of these, but may reside in two or more of these combined together. The examples are given for illustration only, and not for limitation.