Abstract:
A lock component comprises a mounting plate ( 50 ). An intermediate resilient element ( 56 ) is mounted on the plate and has a peg ( 59 ) engaging a recess ( 53 ) on the plate to prevent rotation of the intermediate element. The intermediate element presents a collar ( 60 ) and projection ( 61 ) having an outer periphery configured to snugly engage an aperture ( 64 ) in an arm ( 62 ) which carries a lockable element ( 68 ). A connecting element ( 74 ) has a shaft ( 76 ) passing through a central aperture in the intermediate element ( 56 ), thus also extending through the aperture ( 64 ) in the arm ( 62 ). The shaft is connected to an aperture ( 55 ) formed in the mounting plate ( 50 ). The lockable element ( 68 ) has at least one degree of freedom of movement, which may be a rotational movement about the axis of the connecting element ( 74 ), or which may be a lateral movement. When the lockable element ( 68 ) is engaged within the locking arrangement, the intermediate element ( 56 ) is deformed.

Description:
BACKGROUND OF THE INVENTION 
     THE PRESENT INVENTION relates to a lock component, and more particularly relates to a lock component intended to co-operate with a locking mechanism. In particular, the present invention relates to a lock component adapted to co-operate with a locking mechanism suitable for use in locking a foldable back-rest of a vehicle seat, in particular a rear seat. 
     It is desirable to provide the rear seat of a vehicle, such as a passenger car, with a foldable back-rest, since this may facilitate the transportation of a long object or a bulky object within the vehicle. Typically a foldable back-rest is hinged, at the lower portion of the back-rest, to the squab of the seat or to the chassis of the vehicle. A lock is provided to lock the seat in the upright position, and the lock may consist of a locking mechanism secured to the chassis of the vehicle, which co-operates with a lock component which is mounted on the upper part of the back-rest. The lock has to be very strong to be able to withstand substantial forces that may be applied to the back-rest if loose luggage in the boot of the vehicle moves forward during a frontal impact. It is also especially important for the lock to be very strong if the upper anchorage points for the seat-belt system are located in the back-rest of the seat, and not directly mounted on the chassis. 
     However, it has been found that there is relative movement between the chassis of a motor vehicle, such as a car, and a foldable back-rest, when the vehicle is in motion. This relative movement may cause noise problems within the cabin of the motor vehicle, especially if the locking mechanism and the lock component are not properly connected to each other or have a relatively large clearance between them, permitting relative movement. 
     At the present time, to ensure that a foldable rear seat back-rest in a vehicle may be locked in position, the locking mechanism typically includes a lock that defines a slot or passage that is of a sufficient size to accept part of the locking component that is to co-operate with the lock, even if the locking mechanism and the lock component are not perfectly aligned. This means that there is typically a relatively wide clearance between the locking mechanism and the co-operating lock component. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to provide an improved lock component. 
     According to this invention there is provided a lock component, comprising a mounting plate, a deformable element connected to the mounting plate and an arm connected to the deformable element so as to be connected to the mounting plate through the intermediary of the deformable element, the arm carrying a lockable element, the lockable element being adapted to co-operate with and be retained by a locking mechanism, the lockable element having at least one degree of freedom of movement. 
     Preferably the freedom of movement is a rotational freedom of movement. 
     Advantageously the freedom of movement comprises two freedoms of movement, one being rotational and one being a lateral displacement. 
     Preferably the arm presents an aperture having a predetermined configuration, the aperture being dimensioned to receive a portion of the deformable element which has substantially the same configuration. 
     Advantageously the intermediate element is provided with a bore therethrough, the bore being located to be co-aligned with the aperture in the arm when the arm is mounted on the intermediate element, connecting means being provided extending through the aperture in the arm through the intermediate element and extending to the mounting plate. 
     Conveniently the lockable element comprises an element protruding from said arm presenting a first flange, a relatively narrow, cylindrical portion and an enlarged diameter head. 
     Advantageously said flange is chamfered, the narrow cylindrical portion is barrel-shaped and the enlarged diameter head has a substantially domed outward end. 
     Preferably the arm is cranked. 
     Conveniently the deformable element is resiliently deformable, such as a resiliently deformable polymer material. 
     The invention also relates to a component as described above in combination with a locking mechanism, the locking mechanism defining a slot to receive the lockable element, the relative position between the slot and the said component being such that when the lockable element is inserted into the slot, the intermediate element is distorted. 
     Preferably the locking mechanism comprises a front plate defining said slot and a rotatable lock plate defining a recess adapted to receive part of the said lockable element, the lock plate being movable to a position in which the lockable element is retained within the slot. 
     The lock component and locking mechanism may be mounted in the motor vehicle to retain a foldable back-rest of a vehicle seat in an elevated position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: 
     FIG. 1 is an enlarged view of a lock mechanism shown together with a lock component in accordance with the invention, 
     FIG. 2 is an exploded view of the lock mechanism, 
     FIG. 3 is a front view of the lock component, 
     FIG. 4 is a partially exploded view corresponding to FIG. 3, 
     FIG. 5 is an exploded view of the lock component shown from the rear, 
     FIG. 6 is a top plan view of the lock component and locking mechanism when engaged, 
     FIG. 7 is a view corresponding to FIG. 6 showing the situation when the lock component is displaced relative to the locking mechanism, and 
     FIG. 8 is an enlarged view of part of FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring initially to FIG. 1 of the accompanying drawings, a locking mechanism  1  is illustrated which is adapted to be mounted on the chassis of a motor vehicle. A lock component  2  is also illustrated, which is to co-operate with the locking mechanism and which is adapted to be mounted on part of a back-rest of a rear seat within the vehicle. As will become clear, hereinafter, the lock component  2  carries a lockable element which can be retained by the locking mechanism  1 . 
     Referring now to FIG. 2 of the accompanying drawings, the locking mechanism  1  comprises a front plate  3  carrying, at one vertical edge thereof, a rearwardly extending flange  4 . The front plate  3  is provided with an elongate slot  5 . The elongate slot  5  has a first portion  6  located adjacent the flange  4  and communicating with a recess  7  which is formed in the flange  4 , thus extending transversely of the plane of the front plate  3 . The side-walls of the first portion  6  of the slot diverge to form a relatively wide open mouth at the end of the slot. The first portion  6  of the slot  5  is curved, and is curved about a centre of curvature located beneath the slot  5 . The slot  5  continues with a generally horizontally extending portion that terminates with an upwardly curved terminal region  8 , the terminal region  8  being curved upwardly about a centre of curvature which is located above the slot  5 . The front plate  3  is provided with three spaced-apart apertures  9 ,  10 ,  11 , adapted to receive connecting rivets. The front plate  3  is also provided with a short arcuate slot  12  and a pivot aperture  13 . 
     Co-operating with the front plate  3  is a back plate  14 , which is spaced from and parallel with the front plate. The back plate  14  is a planar element, and defines three apertures  15 ,  16 ,  17 , co-aligned with and corresponding to the apertures  9 ,  10  and  11  to receive connecting rivets. The back plate  14  is also provided with an arcuate aperture  18  corresponding with and aligned with the slot  12  in the front plate, and is also provided with an aperture  19 , which is of greater diameter than, but which is aligned with the pivot aperture  13  provided in the front plate. 
     The back plate  14  is provided with a further aperture  20  which is substantially centrally located between the three apertures  15 ,  16 ,  17  to receive a mounting bush. A mounting bush  21  is provided adapted to be received within the aperture  20 , and a lock plate  22  is provided, having a central aperture  23  adapted to be mounted on the bush  21 , with the bush  21  passing through the aperture  23  so that the lock plate  22  is rotatable about an axis substantially coincident with the centre of the aperture  20 . The forward part of the lock plate  22  is provided with a “U”-shaped recess  24  which is initially aligned with the first part  6  of the slot  5  where the first part  6  of the slot  5  merges into the recess  7  provided in the flange  4 , and defines the open mouth. The periphery of the lock member  22  is also provided with two recesses, at spaced-apart positions  25 ,  26 . 
     The periphery of the lock member  22  is also provided with an abutment  27 , the abutment  27  being adapted to engage one end  28  of a helical spring  29  adapted to surround the bush  21 . The other end of the spring  29  extends linearly,  30 , from the helical portion of the spring, and is adapted to engage one of three rivets  31 ,  32 ,  33  provided which pass through the co-aligned apertures  9 ,  15 ,  10 ,  16  and  11 ,  17  respectively, in order to secure the back plate to the front plate  3 . The lock member  22  is thus biased by the spring  29 . 
     Mounted between the front plate and the back plate is an actuating lever  34  which has a first trunion  35  of relatively small diameter passing through the pivot aperture  13 , and a second opposed trunion  36  of a relatively large diameter passing through co-aligned aperture  19  formed in the back plate  14 . The lever may pivot about the axis defined by the trunions. The lever  34  has a bifurcated end  37 , the bifurcated end  37  carrying a transverse rod  38 , having end portions which project beyond the bifurcated end. The projecting ends of the rod  38  are received within the arcuate slots  12  and  18 . The part of the rod  38  centrally disposed at the bifurcated end  37  of the actuating lever  34  is adapted to be engaged selectively in the recess  25 , or in the recess  26  formed in the periphery of the lock plate  22  to retain the lock plate  22  in predetermined positions. The operating lever  34  is associated with a spring  39  having a central helical portion, one projecting end  40  being adapted to engage one end of the rod  38 , and another linear projecting end  41  being adapted to engage one of the rivets  33  so that the lever  34  is spring-biased in such a way that the rod  38  is spring-biased into engagement with one of the recesses  25  or  26  of the lock plate  22 . 
     The locking mechanism  1 , as described above, is intended to co-operate with the lock component  2  which is shown more clearly in FIGS. 3 to  5 . The lock component  2  comprises a generally triangular mounting plate  50  provided with two apertures  51 ,  52  adapted to receive mounting screws by means of which the plate may be secured in position. The apertures  51  and  52  are formed adjacent two corners of the generally triangular plate  50 . A peripheral “U”-shaped recess  53  is formed adjacent the third corner of the plate  50  for a reason that will become clear hereinafter. The central part of the plate  50  is dished upwardly, as shown in FIG. 4, to form a dome-shaped projection  54 . An aperture  55  of circular form is provided at the apex of the dome-shaped projection. A flat land may surround the aperture  55 . 
     A resilient intermediate element  56  formed of a yieldable or deformable resilent polymer material such as, for example, polyurethane is provided. The element  56  is provided with a generally planar lower portion  57  adapted to abut the mounting element  50 . The planar lower portion may rest on the land surrounding the aperture  55 . The element  56  defines an aperture  58  having a diameter which is slightly greater than the diameter of the aperture  55 , but which is adapted to be co-aligned therewith. The under-surface of the element  56  is shaped and dimensioned to co-operate with that of the mounting plate  50  which surrounds the aperture  55 . The under-part of the element  56  is provided with a projecting cylindrical per  59  dimensioned and located to be received within the recess  53 . This will prevent rotation of the element  56  about the axis of the aperture  58 . 
     The upper part of the element  56 , as shown in FIG. 4, defines a projecting collar  60  surrounding the aperture  58  and presenting a substantially circular exterior, the collar being provided with a generally “U”-shaped projection  61  which extends radially outwardly from the collar whilst lying in the plane of the collar. 
     The intermediate element supports a rigid arm  62 . One end of the arm  62  comprises a planar portion  63  defining an aperture  64 . The periphery of the aperture  64  has a configuration corresponding to the configuration of the periphery of the collar  60 , and the “U”-shaped projection  61 . The arrangement is such that the aperture  64  may be brought into snug engagement with the collar  60  and the projection  61  to mount the rigid arm on the intermediate element. 
     The planar portion  63  of the arm  62  is connected by a forwardly cranked portion  65  of the arm to a terminal planar region  66  which is spaced from, but parallel with the planar region  63 . The region  66  is provided with an aperture  67  (see FIG.  5 ). 
     Mounted within the aperture  67  is a lockable element  68  in the form of a rivet. The rivet  68  comprises a cylindrical shank  69  adapted to be passed through the aperture  67  and peened over to form a rivet head  70  (see FIG.  8 ). The rivet is provided with an outwardly directed flange  71  adapted to abut the face of the planar portion  66  of the arm  62  remote from the peened over-head  70 , and is then provided with a relatively narrow cylindrical portion  72  connecting the flange to an enlarged diameter head  73 . 
     It is to be observed (see FIG. 8) that the upper surface of the flange  71  directed towards the cylindrical portion  72 , is chamfered slightly towards the periphery of the flange. The cylindrical portion  72  is slightly barrelled, having a greater diameter at the centre than at each of the opposed ends. The large diameter head  73  has a slightly “domed” upper surface. 
     A connecting element  74  is provided having a circular head  75  connected to a first cylindrical portion  76  having a diameter equivalent to the interior diameter of the aperture  58  and having a terminal cylindrical portion  77  having a diameter equivalent to the diameter of the aperture  55  provided in mounting plate  50 . The connecting element  74  may be mounted in position with the cylindrical portion  76  passing though the aperture  58  provided in the resilient, or yieldable intermediate element  56 , and the enlarged head thus overlying the upper part of the collar  60  and also part of the planar portion  63  of the arm  62 . The end of the cylindrical portion  77  passing through the aperture  55  in the mounting plate  50  may be peened over to from a rivet head. The rivet head is received within the dome-shaped projection  54 . 
     It is to be appreciated, therefore, that the arm  62  is mounted on the mounting plate  50  via the intermediary of the resilient or deformable element  56 . The arm  62  may thus rotate, with a consequent deformation of the resilient or yieldable intermediate element  56 , about an axis co-incident with the axis of the connecting element  74 , and may also move such that the lockable element  68  moves forwardly and backwardly, along an axis substantially parallel with the axis of the lockable element  68 , with a compression and contraction of parts of the yieldable resilient intermediate element  56 . Thus, in the described embodiment, the lockable element may move relative to the mounting plate with various degrees of freedom of movement, although such movement is resisted, but not prevented, by the resilient, or yieldable intermediate element  56 . As the lockable element  68  moves from an initial or rest position, the intermediate element  56  will apply a bias tending to return it to that initial or rest position. 
     It is to be appreciated that the locking mechanism  1 , as described above, is mounted on the chassis of a motor vehicle, and the lock component  2  is mounted on the back-rest of a rear seat. The lock element may be moved to a first position in which the “U”-shaped recess  24  present in the locking plate  22  is aligned with the open mouth of the channel  6 . The back-rest of the seat may then be moved to an elevated position, bringing the lock component  2  towards the locking mechanism  1 . The lockable element  68  will then become inserted in the first part  6  of the slot  5 . It is to be observed that the open end of the first part  6  of the slot  5 , as formed in the front plate  3  of the locking mechanism is diverging, and thus if there is a slight misalignment of the lockable element  68  and the slot  5 , the lockable element  68  will be guided into the slot  5 . The head  73  of the lockable element engages the recess  24  in the locking element  22 , and the relatively and narrow cylindrical portion  72  will be guided into the slot  5 . The plate  22  will, as the lockable element  68  is moved further into the slot  5 , rotate until the rod  38  carried by the lever  34  is snapped, under the resilient force provided by the spring  39 , into the recess  25 . The lockable element  68  is thus retained within the locking mechanism  1 . However, as the lockable element  68  is being drawn into the slot  6 , the lockable element  68  has passed round the curved portion  6  of the slot  5  which has its centre of curvature located beneath the slot  5 . The aim  62  will have been moved, thus defining the intermediate element  56 , and thus experiences a resilient bias provided by the deformable or yieldable element  56 . The bias will therefore be applied to the lockable element  68  forcing the lockable element  68  into firm contact with part of the locking mechanism. Thus the lock will not rattle. 
     If desired, the lever  34  may be manually operated to remove the rod  38  from the recess  25  in the locking element  22 , and the back-rest of the seat may be further adjusted to move the lockable element  68  further along the slot  5  until the lockable element reaches the terminal region  8  of the slot  5 . The rod  38  will then be again biased by the spring  39  into the recess  26 . The back-rest may, in this way, be locked in a further more reclined position. 
     By operating the lever  34 , the rod  38  may be disengaged from the recess  26 , and also from the recess  25  to permit the back-rest to be pivoted forwardly, thus moving the lockable element out of the slot  5  to disengage the lockable element  68  from the locking mechanism  1 . 
     Referring initially to FIG. 6 of the accompanying drawings it can be seen that the arm  62  is cranked, or bent so that the base of the lockable element  68  that is mounted on the aim is relatively close to the locking mechanism  1 . Thus any moment of force which is applied through the lockable element  68  to the arm  62  as the lockable element  68  enters the locking mechanism  1  is relatively low, since the distance between the enlarged diameter head  73 , to which any such force will be applied, and the point of connected between the lockable element  68  and the arm  62 , where the moment of force will be applied, is relatively short. If the arm  62  was not cranked, the length of the lockable element  68  would be substantially greater, meaning that a greater moment of force would be applied, causing the connection between the lockable element  68  and the arm  62  to have to have a very substantial strength. 
     Referring to FIG.  7  and FIG. 8, it can be seen that if there is any tendency for the mounting plate  50  of the lock component  2  to move inwardly and outwardly relative to the locking mechanism  1 , that is to say any tendency for the mounting plate  50  of the lock component  2  to move in the direction indicated by the arrows  80 , as shown in FIG. 7, the lockable element  68  may rotate slightly about a notional axis, substantially aligned with the centre of the barrelled cylindrical portion  72 , with a simultaneous deformation of the intermediate resilient intermediate element  56 . 
     It can be seen, from FIG. 8, that because the flange  71  has a bevelled upper surface, and because the cylindrical portion has a “barrelled” configuration and because the end of the enlarged diameter head  73  is slightly domed, the lockable element  68  may rotate about a notional axis of rotation co-incident with the centre of the cylindrical portion  72  as the arm  62  deforms the intermediate yieldable resilient element  56 . If the lockable element  68  did not have such design features, any movement of the lock component  2  in the direction of the arrow  80  as shown in FIG. 7 might result in permanent damage being effected to the locking mechanism and/or the lock component. 
     It is to be noted that in embodiments of the invention the arm  62  is mounted relative to the mounting plate  50  by the intermediate resilient element  56 . Thus, any movement of the arm  62  is transmitted to the intermediate element  56  which consequently deforms. However, it is to be noted that the connecting element  74  actually passes through the centre of the aperture  64  formed in the arm  62 . Thus, even if a very substantial force is applied to the lockable element  68 , and that force is transferred to the arm  62 , even if the intermediate element  56  does not have sufficient strength to withstand the force and thus collapses or disintegrates, the periphery of the aperture  64  formed in the arm  62  will then be brought into contact with the connecting element  74 . The connecting element  74  is thus designed to have substantial strength so that, even if the described lock component  2  is subjected to very severe forces, the component does not totally disintegrate or fail. 
     In the present specification “comprise” means “includes or consists of” and “comprising” means “including or consisting of”. 
     The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.