Abstract:
In a gear shaft mechanism is provided that includes, but is not limited to a gear stick passing through slots in a plate to operate a shifter mechanism to move control cables, The gear stick is not pivotally mounted and performs only translational movements. The shaft is fixed to a bar member that is constrained to slide in a first direction relative to a frame member and the frame member is arranged to slide relative to a fixed support in a second direction. The second direction is substantially perpendicular to the first direction. A first pivot is arranged to slide on the bar member and the mechanism further includes, but is not limited to a two-armed lever pivoted at the junction of its arms to a second pivot fixed to said fixed support, a first arm of the lever being pivotally connected to the first pivot. The control cables are respectively connected to a second arm of the lever and the frame member.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to British Patent Application No. 0921032.9, filed Dec. 1, 2009, which is incorporated herein by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The technical field relates to a manual gear shifter for automotive vehicles. 
       BACKGROUND 
       [0003]    Conventional manual gear shift mechanisms comprise a gear stick or lever coupled by means of movement-translating components to one end of a dual cable arrangement. The other ends of the two cables are connected to a transmission unit comprising a plurality of gears, and the positions of the cables determine which gear is currently selected to drive the vehicle. The gear shift lever is connected to the movement-translating components via a ball joint mechanism. The gears are operated by moving the gear shift lever forwards and backwards, which produces rotation of the ball joint about a transverse axis, or from side-to-side, which produces rotation of the ball joint about a longitudinal axis. An example of such a manual gear shift mechanism is disclosed in U.S. Pat. No. 4,270,403. 
         [0004]    A disadvantage of existing gear shifts levers is that they project a relatively long way into the interior space of the vehicle. Accordingly, it is desirable to seek to overcome, or at least reduce this above problem. In addition, it is desirable to seek to provide a manual gear shift mechanism that does not require a gear shift lever to pivot. Furthermore, other desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background. 
       SUMMARY 
       [0005]    A gear shift mechanism is provided comprising a manually operated shaft which is mounted to perform substantially translational movements. An advantage of avoiding rotating movements of the gear shaft is that it can be configured to protrude less into the interior of a vehicle. 
         [0006]    Preferably the shaft extends through a slotted opening in a substantially planar member, a manual control element being provided at one side of the planar member and a shifter mechanism being provided at the other side of the planar member. The shifter mechanism being arranged to operate two control cables of a transmission device. By suitable adaptation of the shifter mechanism, the cables can be used to control the transmission device in a known way. Thus the gear shift mechanism can be retro-fitted without requiring modifications of the transmission device. 
         [0007]    In a preferred embodiment, the shaft is fixed to a bar member that is constrained to slide in a first direction relative to a frame member, the frame member being arranged to slide relative to a fixed support in a second direction. The second direction being substantially perpendicular to said first direction, a first pivot being arranged to slide on said bar member, the mechanism further comprising a two-armed lever pivoted at the junction of its arms to a second pivot fixed to the fixed support, a first arm of the lever being pivotally connected to the first pivot. This arrangement constitutes a convenient way of converting movements by the user of the shaft into suitable movements of the control cables. 
         [0008]    According to a second embodiment, a gear shift mechanism is provided comprising a manually operated gear stick passing through a slotted opening to a shifter mechanism connected to the first ends of two control cables, the other ends of which are directly or indirectly connected to respective control members of a gear transmission device, wherein the stick is non-rotatably mounted. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and: 
           [0010]      FIG. 1  shows a diagrammatic view of a plate of a manual gear shift mechanism; 
           [0011]      FIG. 2  shows a diagrammatic view of a selection path of movement of the mechanism of  FIG. 1 ; 
           [0012]      FIG. 3  shows a diagrammatic view of a shifting path of movement of the mechanism of  FIG. 1 ; 
           [0013]      FIG. 4  shows a diagrammatic view of the connection of the mechanism of  FIG. 1  to first ends of control cables, the second ends of that are connected to a gear transmission device; 
           [0014]      FIG. 5  shows a perspective view of a gear shift knob and plate of a manual gear shift mechanism in accordance with a first embodiment; 
           [0015]      FIG. 6  shows a view of the combination of  FIG. 5  installed in a centre-stack of a vehicle; 
           [0016]      FIG. 7  shows a top view of the shifter mechanism provided below the combination of  FIG. 5  with the mechanism in a gear select or neutral position; 
           [0017]      FIG. 8  shows a view similar to  FIG. 7  with the mechanisms moved so that other gears may be selected; 
           [0018]      FIG. 9  shows a top view of the shifter mechanism of  FIG. 7  and  FIG. 8  in a gear shift position into which it has been moved so that a particular gear is engaged in the drive train of the vehicle; 
           [0019]      FIG. 10  shows a view similar to  FIG. 9  with the mechanism moved into another gear shift position so that a different gear is engaged; 
           [0020]      FIG. 11  shows a perspective view of a manual gear shift mechanism in accordance with a second embodiment installed in a centre-stack of a vehicle; 
           [0021]      FIG. 12  is a diagrammatic view of the connection between the mechanism of  FIG. 11  and a gear transmission device of the vehicle; 
           [0022]      FIG. 13  is a diagrammatic view of a modification of the first embodiment in a first gear shift position; and 
           [0023]      FIG. 14  is a view similar to  FIG. 13  with the mechanism in a second gear shift position. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description. 
         [0025]    In the present specification, expressions such as top, bottom, above, below, upper and lower are used merely to assist explanation and do not limit features to any particular orientation in space. 
         [0026]    Referring to the drawings, a plate  12  of a conventional manual gear shift mechanism  10  with slots  14  extending in a fore and aft direction of the vehicle, corresponding to respective vehicle gears, and a transverse slot  16  corresponding to a neutral position in which no gear is engaged. A gear shaft or lever, indicated schematically by a line  18 , moves along slots  14 ,  16  under the control of a knob or grip (not shown) at the top end of the shaft. At the bottom end of the shaft  18  and below plate  12 , the shaft is mounted on a ball joint  20 , or, as shown in  FIG. 2  and  FIG. 3 , two ball joints  22 ,  24 .  FIG. 2  shows the shaft  18  moving along a selection path in neutral position to cause rotation of the ball joints.  FIG. 3  shows the shaft  18  moving along a shift path to cause engagement of a gear.  FIG. 4  represents schematically how rotation of the ball joints causes a first control cable  32  to operate a gear transmission device in one way. In addition,  FIG. 4  represents how the longitudinal movement of  FIG. 3  causes a second control cable  34  to operate the gear transmission device in a different way. To enable the shaft  18  to be able to move the ball joints  20 ,  22 ,  24  to their operating positions, the shaft needs to pivot to reach the ends of slots  14 ,  16 . Thus the shaft  18  needs to project a considerable distance above plate  12 . 
         [0027]    Referring now to  FIG. 5 , a manual gear shift mechanism  50  in accordance with a first embodiment comprises a knob  52  which moves over the top surface of a plate  12  to constitute a gear selector. The knob is mounted at the top of a shaft  58  which extends through slots  14  or  16  in the plate. Instead of pivoting in use, shaft  58  is arranged to project substantially vertically downwardly through slots  14 ,  16  at all times so that knob  52  can travel on or closely above the top surface of plate  12 . The movements of knob  52  are thus translational movements and not pivotal movements. 
         [0028]      FIG. 6  shows the knob  52  of  FIG. 5  located so as to be mounted above a centre-stack  62  of a vehicle. The two cables  32 ,  34  to be operated by the gear shift mechanism  50  are also shown in  FIG. 6 . 
         [0029]      FIG. 7  shows a shifter mechanism  70  located below the plate  12  in  FIG. 5  and arranged to translate the movements of shaft  58  into movement of the cables  32 ,  34 . The shifter mechanism is arranged within a fixed housing  72  inside which moves the bottom end of shaft  58  attach to a block  58 ′. A bar member  68  is fixed to the block  58 ′ and a pivot  74  is attached to bar member  68  to slide there along. A flat lever element  76  pivots around a fixed pivot  78  which is fixedly mounted on housing  72 . The end of one arm  82  of the lever element is rotatably attached to pivot  74 . At the end of another arm  84  of the lever element there is provided a hole  86  for the connection of the select cable  32 . 
         [0030]    The sides  92 ,  94  of block  58 ′ are arranged to slide on opposed internal sides  96 ,  98  of a rectangular aperture  102  formed in a shift frame  100 , which extends across substantially the entire width of housing  72 . Frame  100  has external sides  104 ,  106  which are arranged to slide on opposed internal sides  108 ,  110  of the housing  72 . The other external sides  112 ,  114  of frame  100  are each formed with a recessed edge  116  arranged between corner projections  120 . The major surface of bar member  68  not visible in  FIG. 7  is provided with formations which allow the bar member to slide along the edges  116 . The length of the edges  116  corresponds substantially to the maximum possible range of movement of block  58 ′ along aperture  102 . One of the corner projections  120  is provided with a hole  122  for the connection of the shift cable  34 . 
         [0031]    The way in which shifter mechanism  50  operates will now be described.  FIG. 7  shows the mechanism in a neutral or selection position with the mechanism ready to select certain gears. In  FIG. 8 , shaft  58  has moved to the opposite end of slot  16  so that the mechanism is ready to select other gears. During this movement edges  92 ,  94  have slid along respective sides  96 ,  98  and the formations on bar member  68  have slid along respective edges  116 . Frame  100  has remained in the same position, but lever element  76  has been pivoted so that select cable  32  has been moved. 
         [0032]    It will be appreciated that movement of shaft  58  between the position of  FIG. 7  and  FIG. 8  correspond to side-to-side movements of knob  52 . When used in connection with plate  12 , there will also be two operative intermediate positions substantially equally-spaced between the positions of  FIG. 7  and  FIG. 8  and corresponding to the inner two slots  14 . In these intermediate positions, the mechanism is ready to select respective further gears. 
         [0033]    In  FIG. 9 , shaft  58  has been moved along a slot  14  in plate  12  so that, compared to  FIG. 7 , frame  100  has been moved towards an end  130  of housing  72 . The  FIG. 7  position is shown in broken lines. Thus edges  104 ,  106  have slid along respective edges  108 ,  110 . At the same time, pivot  74  has slid along bar member  68  so that the pivotal position of lever element  76  has not changed as compared to  FIG. 7 , and thus the position of cable  32  has not changed. By virtue of the connection of cable  34  to hole  122  in frame  100 , this cable has been moved so as to engage a gear in the transmission device at its other end. 
         [0034]      FIG. 10  shows the frame  100  moved towards the opposite end  132  of the housing  72 . The  FIG. 8  position is shown in broken lines and it will be noted that the pivotal position of lever element  76  has not changed, and thus the position of cable  32  has not changed as compared to  FIG. 8 . However, the movement of frame  100  has been produced a different movement of cable  34 . It will be appreciated that the movements between  FIG. 7 ,  FIG. 9  and  FIG. 10  correspond to fore and aft movements of knob  52  and shaft  58 . Thus it will be appreciated that the shift mechanism  50  provides a convenient way to enable the translational movements of knob  52  to be converted into operational movement of control cables  32 ,  34 . By permitting movements of knob  52  which are co-planar, or at least substantially co-planar, the length of shaft  58  projecting above plate  12  can be kept to a minimum. In fact the spacing can be effectively zero so that knob  52  slides on the upper surface of plate  12 . This leads to a saving of space, and the inconvenience of a length of shaft  58  projecting into the interior of the vehicle is avoided. Accordingly the driver and other users of the vehicle enjoy a greater degree of freedom of movement without snagging the gear controls. In addition, the compact design has a pleasing appearance. Since the knob  52  substantially covers the plate  12  and conceals shaft  58  it gives the appearance of hovering or floating unsupported over the plate. Moreover, it gives freedom of design to other aspects of a vehicle. 
         [0035]    No modifications are needed to the gear transmission device at the other end of the cables  32 ,  34 . Various modifications can be made to the above-described embodiment. For example the plate  12  may be slightly curved transversely and/or longitudinally. The shifter mechanism  70  still operates in the same way, but the surface contour of plate  12  may be adapted to control the dynamic operation of the shifter mechanism. The shapes and relative sizes of the components of shifter mechanism may be selected as desired. Hole  86  can be provided at any convenient location along lever arm  84 , and hole  122  can be provided at any convenient location on frame  100 . A plurality of holes  86  can be provided to give additional options for the cable transmission ratio when retro-fitting the gear select mechanism. Housing  72  can be replaced by any suitable fixed support, provided it still has the required slide surfaces. 
         [0036]      FIG. 11  and  FIG. 12  show a manual gear shift mechanism  140  in accordance with a second embodiment. A shifter grip  142  mounted on an integral shaft  144  is moveable over the surface of a center-stack  146 . The shape and position of grip  142  are ergonomically suited to a driver&#39;s hand. The bottom end  144 ′ of shaft  144  is connected by means of a shifter mechanism (not shown) to control cables for a gear transmission device. One of these cables is shown at  148  in  FIG. 12  as being connected to a fixed arm  152  of a pivotal linkage  150  connected to the center-stack  146 . The other arm  154  of the pivotal linkage is connected via a cable  156  to the gear transmission device. The use of the linkage  150  has the advantage of permitting adjustment of the cable transmission ratio between the grip  142  and the transmission device, enabling the gear shift mechanism  140  to be retro-fitted. The same modification may also be made to the first embodiment. 
         [0037]      FIG. 13  and  FIG. 14  show a modification  70 ′ of the shifter mechanism  70  of  FIG. 7  to  FIG. 10  in that a toothed rack-and-pinion mechanism  160  is provided. A fixed toothed element  162  is fixedly attached to a housing  72 . A toothed segment  164  is pivotally attached at pivot  168  to frame  100 , e.g. adjacent the position of hole  122 . Segment  164  has a hole  166  to which cable  34  is attached instead of to hole  122 . This enables the cable transmission ratio to be varied between the knob  52  and the transmission device, making the modified gear shaft mechanism easier to retro-fit. The toothed elements may be replaced by any other suitable gearing mechanism between frame  100  and the cable  34 . This modification, together with the other medications mentioned in connection with the first embodiment, may also be made to the second embodiment. The various transmission ratio adjusting devices can be used alone or in combination on the cables as appropriate. The shift mechanism may be arranged at locations other than in a centre-stack; for example they can be in a console. 
         [0038]    While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.