Abstract:
A vehicle seat anchorage ( 22 ) assembly employs a cam ( 34 ) mounted in an anchorage member ( 24 ) for rotation about an axis transverse of the anchorage member between: an unlocked position (FIG.  17 A) in which the cam allows a pair of locking members ( 70  and  72 ) to assume their unlocked positions, and a locked position (FIG.  17 B) in which the cam pushes down on inner portions ( 82 ) of the locking members so that outer portions ( 84 ) of the locking members assume their locked positions engaging under lips ( 12 ) of an anchorage rail ( 10 ).

Description:
CROSS REFERENCED TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 USC §119 to British Patent Application No. 1208222.8 filed on May 15, 2012, which application is hereby incorporated by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    This invention relates to a seat anchorage assembly for use with a vehicle floor anchorage rail such as that illustrated in  FIG. 1  of the accompanying drawings, which has an upwardly facing channel with a pair of inturned lips between which there is a gap and below which there is a channel. 
       BACKGROUND OF THE INVENTION 
       [0003]    In particular, the anchorage assembly of the present invention seeks to improve on the assembly described in EP 1407920A, in which the assembly comprises an elongate tubular anchorage member for resting on the anchorage rail and a locking mechanism comprising a pair of locking members pivotally connected to each other, the locking members each passing through an aperture in the underside of the anchorage member so that each locking member has an inner portion disposed inside the tubular member and an outer portion below the tubular member. The locking members are movable between an unlocked position, in which the outer portions can pass through the gap in the channel of the floor anchorage rail, and a locked position, when the inner portions are pushed downwardly inside the anchorage member, in which the outer portions engage under the lips of the floor anchorage rail. A cam mechanism is mounted in the anchorage member and is movable between an unlocked position, in which the cam allows the locking members to assume their unlocked positions, and a locked position, in which the cam causes the locking members to assume their locked positions. 
         [0004]    Although the anchorage assembly described in EP 1407920A can provide a very strong lock between the seat anchorage member and the floor anchorage rail, the cam mechanism is relatively complicated in construction, expensive and difficult to assemble. The mechanism employs a rotatable cam barrel which causes longitudinal movement of a cam block which in turn, via a number of ramped recesses in the cam block and associated rollers, presses down on the inner portions of the locking elements. 
         [0005]    An object of the present invention is to improve on the anchorage assembly described in EP 1407920A. 
       SUMMARY OF THE INVENTION 
       [0006]    According to the present invention there is provided a seat anchorage assembly for use with a vehicle floor anchorage rail having an upwardly facing channel with a pair of inturned lips between which there is a gap and below which the channel is wider internally, the anchorage rail having a series of widened portions in the gap between the inturned lips so that there are narrowed portions between the widened portions;
       the seat anchorage assembly comprising:   an elongate tubular anchorage member for resting on the anchorage rail;   a locking mechanism comprising a pair of locking members pivotally connected to each other, the locking members each passing through an aperture in the underside of the anchorage member so that each locking member has an inner portion disposed inside the tubular member and an outer portion below the tubular member, the locking members being movable between:   an unlocked position in which the outer portions can pass through the gap in the channel of the floor anchorage rail, and   a locked position, when the inner portions are pushed downwardly inside the anchorage member, in which the outer portions engage under the lips of the floor anchorage rail; and   a cam mounted in the anchorage member for rotation about an axis transverse of the anchorage member between:   an unlocked position in which the cam allows the locking members to assume their unlocked positions, and   a locked position in which the cam pushes down on the inner portions of the locking members so that they assume their locked positions;   and a locking foot mounted on the anchorage member at a position longitudinally spaced from the locking members for movement longitudinally of the anchorage member, the locking foot having a size such that it can pass through the widened portions of the gap in the anchorage rail, but not the narrowed portions; and   a foot-operating mechanism operably connected between the cam and the locking foot so that movement of the cam between its unlocked and locked positions causes movement of the locking foot longitudinally of the anchorage member.       
 
         [0017]    The cam may bear directly on the inner portions of the locking members. However, a simple pressure plate is preferably disposed between a cam surface of the cam and the inner portions of the locking members. 
         [0018]    A positioning member is preferably fixed to the anchorage member for insertion into one of the widened portions of the gap in the anchorage rail, the positioning member being such that it cannot enter the narrowed portions of the gap in the anchorage rail. 
         [0019]    In the case where the anchorage assembly is for use with an anchorage rail in which the widened portions of the gap have a uniform standard pitch, such as 1 inch (25.4 mm), when the cam is in its unlocked position, the centre-spacing of the locking foot and the positioning member is preferably substantially equal to an integral multiple of the standard pitch, for example 2 inches (50.8 mm), and when the cam is in its locked position, the centre-spacing of the locking foot and the positioning member is preferably substantially different to an integral multiple of the standard pitch, for example 1½ inches (38.1 mm). 
         [0020]    The seat anchorage assembly preferably further includes a manually operable handle member operably connected to the cam for moving the cam between its unlocked and locked positions. In this case, the foot-operating mechanism may include a cam follower which cooperates with a second cam provided by the handle member. The invention also extends to such a seat anchorage assembly in combination with vehicle floor anchorage rail. 
         [0021]    The invention furthermore extends to a vehicle seat having a pair of such seat anchorage assemblies. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is an isometric view of a known floor anchorage rail; 
           [0023]      FIGS. 2A and 2B  are isometric views of a seat anchorage member; 
           [0024]      FIG. 3  is an isometric view of a longitudinal positioning plug for the anchorage member; 
           [0025]      FIGS. 4A and 4B  are isometric views of a linkage; 
           [0026]      FIG. 5  is an isometric view of an operating bolt for the linkage; 
           [0027]      FIG. 6  is an isometric view of a locking foot for the linkage; 
           [0028]      FIGS. 7 &amp; 8  are isometric views of a pair of hinged locking members; 
           [0029]      FIG. 9  is an isometric view of a pivot pin; 
           [0030]      FIG. 10  is a schematic view of a spring; 
           [0031]      FIGS. 11A and 11B  are isometric views of a locking mechanism constructed from the locking members, pivot pin and four of the springs (but with the springs omitted) in a locked position and in an unlocked position, respectively; 
           [0032]      FIG. 12  is an isometric view of a pressure plate; 
           [0033]      FIGS. 13A and 13B  are isometric views of a cam assembly; 
           [0034]      FIG. 14  is an isometric view of an actuating lever; 
           [0035]      FIG. 15  is an isometric view of a seat anchorage assembly constructed from the parts shown in  FIGS. 2 to 14  in its locked position; 
           [0036]      FIGS. 16A and 16B  are similar to  FIG. 15 , but with the anchorage assembly upside down and shown in its unlocked position and locked position, respectively; 
           [0037]      FIGS. 17A and 17B  are end views, on a larger scale, of the anchorage assembly in its unlocked position and locked position, respectively; 
           [0038]      FIGS. 18A and 18B  are sectioned views through the seat anchorage assembly and the floor anchorage rail, taken on the section lines  18 A- 18 A and  18 B- 18 B (shown in  FIGS. 16A and 16B ) through the locking foot, respectively; and 
           [0039]      FIG. 19  is a sectioned view through the seat anchorage assembly and the floor anchorage rail, taken on the section line  19 - 19  (shown in  FIG. 16A ) through the positioning plug. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0040]    Referring to  FIG. 1  of the drawings, an aluminium anchorage rail  10  of known design is of channel section, open at its top, with a pair of inturned lips  12  so that the width A of the gap  14  between the lips  12  is less than the width B of the channel below the lips  12 . The lips  12  are arcuately cut back at regular intervals along the rail  10  to form a series of widened portions  16  of the gap  14  each with a diameter C equal to or slightly less than the width B of the channel below the lips  12 . The widened portions  16  have a pitch D of, for example, 1 inch (25.4 mm). The base of the rail  10  is formed with a series of fixing holes  18  (partly obscured in  FIG. 1 ), by which the rail  10  can be fixed to the floor of a vehicle or to some reinforcing member on the floor. The rail  10  also has a pair of out-turned flanges  20  for covering the edges of a floorcovering on the vehicle floor. 
         [0041]    An anchorage assembly  22  as shown in  FIGS. 15 to 18B  comprises the components  25  shown in  FIGS. 2 to 14 . 
         [0042]    Referring in particular to  FIGS. 2A and 2B , an anchorage member  24  is formed from a length of steel square-section tube. An elongate rectangular aperture  26  (for receiving a locking assembly  28  as shown in  FIGS. 11A and 11B ) is formed in the bottom of the member  24  adjacent its front end  30 . Opposed holes  32  (for receiving a cam member  34  as shown in  FIGS. 13A and 13B ) are formed in the sides of the member  24  about half-way along the aperture  26 . Behind the hole  32  in one of the sides of the member  24 , a slot  36  (for receiving a linkage operating bolt  38  as shown in  FIG. 5 ) is formed in that side of the member  24 . A hole  40  (for receiving a positioning plug  42  as shown in  FIG. 3 ) and a slot  44  (for receiving a locking foot  46  as shown in  FIG. 6 ) are formed in the bottom of the member  24  adjacent its rear end  48 , with the hole  40  and slot  44  being spaced apart in the longitudinal direction of the anchorage member  24 , and with the slot  44  extending in the longitudinal direction. One or more formations  50  are formed on the top of the anchorage member  24  for securing the legs or frame on one side of a vehicle seat to the member  24 . 
         [0043]    Referring to  FIG. 3 , the steel positioning plug  42  has a fixing portion  52  which is inserted into the hole  40  in the anchorage member  24  and clinched or burred over to hold it fast, as shown in  FIG. 19 . A positioning portion  54  of the plug  42  then projects below the anchorage member  24  and is of a shape and size such that it is a snug fit into any of the widened portions  16  of the gap in the anchorage rail  10 , but cannot slide from one widened portion  16  to the next. 
         [0044]    Referring to  FIG. 4A-B , an elongate linkage  56  is formed by a length of steel angle  58  of a size that fits into and can slide in the anchorage member  24 . Adjacent one end, a threaded hole  60  (for receiving the locking foot  46  of  FIG. 6 ) is formed in the lower limb of the angle  58 . At the other end, an arm  62  projects from the side limb of the angle  58  and is formed with a threaded hole  64  (for receiving the operating screw  38  of  FIG. 5 ). The operating bolt  38  of  FIG. 5  may be provided by a standard steel threaded bolt. 
         [0045]    Referring to  FIG. 6 , the steel locking foot  46  has an upper screw-threaded shank  66  for passing through the slot  44  in the anchorage member  24  and screwing into the hole  60  of the linkage  56 . The shank  66  is of a diameter less than the width A of the narrow portions of the gap  14  in the anchorage rail  10 . At its lower end, the shank  66  has an enlarged portion  68  of a 25 diameter greater than the width A of the narrow portions of the gap  14 , but slightly less than the diameter C of the widened portions  16 . 
         [0046]    Referring now to  FIGS. 7 to 11B , the locking mechanism  28  comprises a pair of brass hinged elongate locking members  70  and  72  which are identical apart from having complementary portions  74  and  76 , respectively, for containing a steel hinge pin  78  which connects the members  70 , 72  for hinging movement about a hinge axis  80 . Each locking member  70 , 72  has an upper portion above the hinge axis  80  with an outwardly directed flange  82 , and a lower portion beneath the hinge axis  80  with an outwardly directed flange  84 . The inner faces of the upper portions are formed with pairs of blind holes  86  to receive the ends of compression coil springs  88  as shown schematically in  FIG. 10  (but which are not shown in  FIGS. 11A and 11B ). The springs  88  serve to urge the upper flanges  82  apart to an unlocked position, as shown in  FIG. 11B , in which the width E occupied by the lower flanges  84  is less than the width A of the narrow portions of the gap  14  in the anchorage rail  10 . However, the locking mechanism  28  can be forced to assume a locked position, as shown in  FIG. 11A , in which the width F occupied by the lower flanges  84  is less than the width A of the narrow portions of the gap  14  in the anchorage rail  10 . 
         [0047]    A pressure plate  90  as shown in  FIG. 12  comprises a strip  92  of steel of a width less than the internal width of the anchorage member  24 , and a pair of posts  94  welded or screwed to the strip  92 . 
         [0048]    Referring to  FIGS. 13A-B , the cam assembly  94  comprises the steel cam member  34  which over the majority of its length is cylindrical, except for an elongate flat  96 , and of a diameter that fits in the holes  32  in the anchorage member  24 . At one end, the cam member  34  has an enlarged cylindrical boss  98  and beyond that a square spigot  100  (to which an operating lever  102  as shown in  FIG. 14  is fitted). The cam assembly  94  also comprises a set screw  104 , with a washer, that screws into a threaded hole to secure the lever  102  to the cam member  34 , and a further set screw  106 , with a washer  108 , that screws into the other end of the cam member  34 . The washer  108  has a larger diameter than the holes  32  in the anchorage member  24  so that the cam assembly  94  can be retained in the anchorage member  24  but is allowed to rotate. 
         [0049]    As shown in  FIG. 14 , the operating lever  102  comprises an arm  110  formed from steel plate with an enlarged portion  112  at one end. A square hole  114  is formed in the enlarged portion  112  to receive the spigot  100  of the cam member  34 . The enlarged portion  112  also has a spiral slot  116  having a width slightly larger than the diameter of the operating bolt  38  of  FIG. 5 . Over an angle of about 45 to 60 degrees centred on the square hole  114 , the distance of the slot  116  from the square hole  116  changes by about one half of the pitch D of the widened portions  16  of the gap  14  in the anchorage rail  10 . 
         [0050]    Referring now to  FIGS. 15 to 19 , the various components described above are assembled into the anchorage assembly  22  so that the upper flanges  82  of the locking mechanism  28  are disposed inside the anchorage member  24 , and the locking mechanism  28  projects through the rectangular aperture  26  in the anchorage member  24  so that the lower flanges  84  of the locking mechanism  28  are disposed outside the anchorage member  24 . The pressure plate  90  rests on top of the locking mechanism  28 . The cam member  34  passes through the holes  32  in the anchorage member  24  and over the strip  92  of the pressure plate  90  between the posts  94 . The cam member  34  is retained by the screw  106  and washer  108 . The square hole  114  in the operating lever  102  is fitted to the spigot  100  on the cam member  34 , and the operating lever  102  is fixed to the cam member  34  by the screw  104  and its washer. The linkage  56  is disposed in the anchorage member  24  with the hole  64  in its arm  62  adjacent the slot  36  in the anchorage member  24  and with the hole  60  in the linkage  56  adjacent the slot  44  in the anchorage member  24 . The shank of the operating bolt  38  passes through the slots  116  and  36  in the operating lever  102  and the anchorage member  24 , and the threaded end of the bolt  38  is screwed into the hole  64  in the linkage  56 . The shank of the locking foot  46  passes through the slot  44  in the anchorage member  24 , and its threaded end is screwed into the hole  60  in the linkage  56 . The positioning plug  42  is fitted to the anchorage member  24  as described above. 
         [0051]    The anchorage assemblies  22  would normally be employed in pairs, with one anchorage assembly  22  being secured to the right-hand side of the base frame of a vehicle seat, and the other anchorage assembly  22  being secured to the left-hand side of the base frame, so that the spacing of the anchorage assemblies  22  is substantially identical to the spacing of a pair of the anchorage rails  10  on the floor of the vehicle to which the seat is to be fitted. The two anchorage assemblies  22  would preferably be mirror images of each other so that the two operating handles are equally accessible. To facilitate this, a slot may be formed in the opposite side wall of the anchorage member  24 , similar to the slot  36 , so that the anchorage member is not handed. The linkage  56  would, however, need to be handed for the right of left anchorage assembly  22 . 
         [0052]    The anchorage assembly is movable between an unlocked state, as shown in  FIGS. 16A and 17A , and a locked state, as shown in  FIGS. 16 ,  16 B and  17 B. In the unlocked state of  FIGS. 16A and 17A , the arm  110  of the operating lever  102  is inclined upwardly, and the flat  96  on the cam member  34  is horizontal underneath the cam member  34 . This permits the upper flanges  82  of the locking members  70 , 72  to be forced apart by the springs  88 , and the lower flanges  84  of the locking members  70 , 72  to be near each other, as shown in particular in  FIG. 17A , so that the lower flanges  84  can be inserted through the gap  14  in the anchorage rail  10 . The linkage  56  and the spiral slot  116  in the operating lever  102  are arranged so that, when the operating lever  102  is in this position, the centre spacing G 1  (see  FIG. 16A ) between the positioning plug  42  and the locking foot  46  is an integral multiple of the pitch D (see  FIG. 1 ) of the widened portions  16  of the gap  14  in the anchorage rail  10 . The plug  42  and the enlarged portion  68  of the locking foot  46  can therefore also be inserted through the gap  14  in the anchorage rail  10 . 
         [0053]    In order to change from the unlocked state to the locked state, the arm  110  of the operating lever  102  is manually pushed downwardly so that it becomes aligned alongside the anchorage member  24 . This action rotates the cam member  34  so that the cam member  34  presses the pressure plate  90  downwardly, which in turn causes the upper flanges  82  of the locking members  70  and  72  to pivot towards each other, and the lower flanges  84  of the locking members  70  and  72  to pivot away from each other, to the locked position as shown in  FIG. 17B . The lower flanges of the locking member  70  and  72  engage underneath the adjacent lip portions  12  of the anchorage rail  10  so as to lock the anchorage member  24  to the anchorage rail  10 . 
         [0054]    Furthermore, this movement of the operating lever  102 , through the action of the spiral slot  116  and the operating bolt  38 , causes the linkage  56  to move by a distance approximately equal to one half of the pitch D of the widened portions  16  of the gap  14  in the anchorage rail  10 , so that the centre spacing G 2  (see  FIG. 16B ) between the positioning plug  42  and the locking foot  46  is about half a pitch D different from an integer multiple of the pitch D. As a result, the enlarged portion  68  of the locking foot  46  becomes engaged underneath the adjacent lip portions  12  of the anchorage rail  10  also so as to lock the anchorage member  24  to the anchorage rail  10 . When the anchorage member  24  is locked to the anchorage rail  10  in this manner, the positioning plug  42  serves to prevent the anchorage member  24  from sliding along the anchorage rail  10 . Provided that the part-cylindrical portion of the cam member  34  rides onto the pressure plate  90  when the assembly  22  is in the locked position, the assembly  22  will remain in the locked position due to friction between the various components. 
         [0055]    In order to change from the locked state to the unlocked state, the arm  110  of the operating lever  102  is manually lifted, and the components of the anchorage assembly  22  revert to their originally described positions so that the anchorage assembly  22  can be removed from the anchorage rail  10 . 
         [0056]    Various modifications and developments may be made to the anchorage assembly described above. 
         [0057]    For example, a catch may be provided to lock the operating lever  102  positively in its locked position to reduce the risk of the lever  102  inadvertently being moved to its unlocked position. The catch may be spring-loaded, or it may be provided by a stop which falls under the influence of gravity to a position where it blocks movement of the lever  102  from its locked position, but which can be raised manually to allow the lever  102  to be moved. 
         [0058]    Also, a resilient crinkle washer may be provided on the shank  66  of the locking foot  46  between the linkage  56  and the lower portion of the anchorage member  24  so as to prevent rattling. 
         [0059]    Furthermore, two of the anchorage assemblies on the same seat may have their cam members  34  interconnected and operated by a single operating lever  102 .