RELATED APPLICATIONS 
       [0001]    The present application is based on, and claims priority from, Taiwan Application Serial Number 95205498, filed Mar. 31, 2006, the disclosure of which is hereby incorporated by reference herein in its entirety. 
       FIELD OF THE INVENTION 
       [0002]    The present invention provides a theft protection chair structure for motor vehicles, especially to a chair structure to prevent thieves from entering the driving space. 
       BACKGROUND OF THE INVENTION 
       [0003]    Conventional motor vehicle theft protection locks may be classified as steering wheel fixing locks and gear fixing locks in accordance with the different parts to be locked. The former, just as its name implies, is mainly to fix the steering wheel, to prevent thieves from controlling the direction of the motor vehicle. And the latter, is to fix the gear lever at neutral gear (N gear) or parking gear (P gear), to prevent thieves from starting the motor vehicle, to achieve the effect of theft protection. However, both the former or the latter, needs locking—manually at the time of parking, and unlocking manually at the time of starting, which is time consuming and complicated. Furthermore, due to frequent locking and unlocking action, the locking part of the steering wheel or the gear are worn out, which results in failure of closely locking the locking part with the lock in the best locking state and so negates the theft protection effect. 
         [0004]      FIG. 1  to  FIG. 3  are schematic views illustrating a conventional motor vehicle chair. The conventional motor vehicle chair is composed of a chair seat  10  and a chair back  11 . According to the drivers&#39; posture and driving habit, the chair seat  10  is generally designed to be moveable forward or backwards toward the steering wheel, and the chair back  11  is designed to rotate about the chair seat  10 , so as to adjust the driving space to fit every driver&#39;s posture and driving habit thereby making the driver comfortable to avoid or reduce tiredness. 
         [0005]    Furthermore, the structure to move the chair seat  10  forward or backward, is mostly formed by adding a pair of guide rails  101  under the driver chair. The guide rails  101  are parallel to each other whereby the chair seat  10  can slide along the guide rails  101  thereby adjusting the driver chair forward or backward. The underside end of the chair back  11  is pivotally connected to the back of the chair seat  10  (not shown). The driver can adjust or fix the slant angle between the chair back  11  and the chair seat  10  through a slant angle adjustment device. 
         [0006]    Conventional angular adjustment devices generally have two kinds of adjustment structures. The first adjustment structure (as illustrated in  FIG. 2 ), commonly named as the Ferris wheel structure, is mostly comprised of a first gear  102  and a second gear  111  gearing into each other. The first gear  102  is pivotally connected to the inside of the chair seat  10 . At one side of the first gear  102 , a manual Ferris wheel  103  is mounted outside the chair seat  10 , to enable the driver to rotate the first gear  102  by hand. Moreover, an axial region A is mounted through the center of the second gear  111 . The axial A is at the underside of the chair back  11 . The second gear  111  gears into the first gear  102 , to control the slant angle between the chair back  11  and chair seat  10 , and to enable the driver to adjust the slant angle of the chair back  11  by controlling the manual Ferris wheel  103 . 
         [0007]    The second adjustment structure (as illustrated in  FIG. 3 ), generally is named as raising structure. Compared to the above said Ferris wheel adjustment structure, the second gear  111  is pivotally connected to the axial region A, and mounted to the chair back  11 , and a raising handle replaces the first gear  102 , to limit the rotation of the second gear  111 . The raising handle includes a handle  20 , which is pivotally connected to the chair seat  10 . The front end  21  of the handle  20  extends out the side of the chair seat  10 , and the backend of the handle  20  is mounted where at least one gear forms a bulge  22 , to limit the angle of the second gear. When the handle  20  is in the fixed state (i.e. state without suffering a force) (as illustrated in  FIG. 3 ), the gear form bulge  22  at the backend of the handle  20  gears into the teeth of the second gear  111 , to secure the chair back  11  at a fixing angle. When the handle  20  is in the released state, the gear form  22  at the backend of the handle  20  retreats from the teeth of gear  111 , to place the chair back  11  in a free state, thereby enabling the driver to adjust the slant angle of the chair back  11 . 
         [0008]    Accordingly, the object of the present invention is to use the characteristics of the vehicle driver chair of being able to move forward and backwards and adjust the slant angle, to enable the driver chair to prevent thieves from entering the driving space, so as to provide a theft protection function. 
       SUMMARY OF THE INVENTION 
       [0009]    The object of the present invention is to provide a theft protection chair structure for motor vehicles which prevents thieves from entering the driving space through a structure enabling to minimize the driving space, thereby providing the theft protection effect. 
         [0010]    Another object of the present invention is to provide a theft protection chair structure for motor vehicles, which easily achieves the best theft protection effect without using additional locks through a chair structure to prevent thieves from entering the driving space. 
         [0011]    To achieve the above said objects, the present invention provides a theft protection chair structure for motor vehicles, to minimize the driving space for the driver. The theft protection chair structure includes a steering wheel, an accelerator pedal and a brake pedal at the front end of the driving space. The chair structure includes: a chair having a chair seat and a chair back pivotally connected to the chair seat, a chair driving structure driving the chair to move forward or backwards toward the driving space, forming a theft protection state or a sitting state, and an angular adjustment device, to adjust the slant angle between the chair back and chair seat. When the chair driving structure is in a theft protection state, the chair seat is horizontally moved to a front end position, to minimize the distance between the front end of the chair seat and the control pedals in the driving space. When the chair driving structure is in a sitting state, the chair seat is horizontally moved to the backend position, to keep a proper distance between the front end of the chair seat and the control pedals, forming a driving space for the drivers. When the chair driving structure is in a sitting state, the angular adjustment device enables the angle between the chair back and the chair seat to be a right angle or an obtuse angle. When the chair driving structure is in a theft protection state, the angular adjustment device enables the angle between the chair back and chair seat to be at an acute angle, and then locks the chair at the angle. Thus, via the angular adjustment device and the chair driving structure, the driving space is reduced, to provide a theft protection effect. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic view illustrating a conventional motor vehicle chair. 
           [0013]      FIG. 2  is a schematic view illustrating a Ferris wheel structure of the conventional motor vehicle chair. 
           [0014]      FIG. 3  is a schematic view illustrating a raising structure of the conventional motor vehicle chair. 
           [0015]      FIG. 4  is a schematic view illustrating the driving space of the theft protection chair structure for motor vehicles of the present invention, wherein the chair is in a theft protection state. 
           [0016]      FIG. 5  is a schematic view illustrating the chair driving structure of the theft protection chair structure for motor vehicles of the present invention. 
           [0017]      FIG. 6  is a schematic view illustrating the angular adjustment device of the theft protection chair structure for motor vehicles in accordance with an embodiment of the present invention. 
           [0018]      FIG. 7  is a schematic view illustrating the motion of the angular adjustment device in  FIG. 6 . 
           [0019]      FIG. 8  is a schematic view illustrating the angular adjustment device in accordance with another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0020]    Referring to the above said object, a preferred embodiment and the schematic views thereof are described herein to illustrate the technical means and the function of the present invention. 
         [0021]    Refer to  FIG. 4  and  FIG. 5 .  FIG. 4  is a schematic view illustrating the driving space of a theft protection chair structure for motor vehicles of the present invention, wherein the chair is in theft protection state.  FIG. 5  is a schematic view illustrating the chair driving structure of the theft protection chair structure for motor vehicles of the present invention. 
         [0022]    As shown in the schematic view, the present invention provides a theft protection chair structure for motor vehicles, to minimize the driving space S for the driver, to prevent thieves from entering the driving space, to provide theft protection effect. A steering wheel S 1 , an accelerator pedal S 2  and a brake pedal S 3  are disposed at the front end of the driving space S. 
         [0023]    The theft protection chair structure for motor vehicles of the present invention includes a chair  30 , a chair driving structure  40  and an angular adjustment device  50 . The chair  30  has a chair seat  31  and chair back  32 . The under side of the chair back  32  is similar to the conventional chair. The chair back  32  is pivotally connected to the backend of chair seat  31  at an axial region A. 
         [0024]    The chair driving structure  40  moves the chair  30  forward or backwards toward the driving space S. In the present embodiment, the chair driving structure  40  includes a driving motor  41  to provide power, a pair of top guide rails  42  mounted to the bottom of the chair  30  and a pair of underside guide rails  43  to guide the moving direction of the chair  30 . The underside guide rails  43  are mounted on the bottom board of the motor vehicle body (not shown) of the driving space, and the pair of the underside guide rails  43  each is mounted with a guide block  431 . The driving motor  41  is mounted to the chair  30 . Each of the two ends of the output axis  411  of the driving motor  41  is separately connected to one screw  413  via a worm gear decelerate box. The screws  413  are screwed through the guide blocks  431 . The driving motor  41  can rotate in a positive direction and a negative direction, via the screw thread on the screw  413 , to push the top guide rails  42  and the chair  30  to move along the underside guide rails  43  forward and backwards. The front end of the underside guide rails  43  are set towards the position of the pedals S 2  and S 3  in the driving space S, and the front end is defined as the first position. Correspondingly, the backend of the underside guide rails is defined as the third position; and a second position is between the first and third position. Generally, the distance between the second and the third position is about 220 mm, which is the same as conventional guide rails, and the distance between the first and the second position in the present embodiment is no less than 60 mm. So, when the chair  30  is between the second and the third position of the underside guide rails  43 , defining it as a sitting state, the size of the driving space can be adjusted to make the driver to sit comfortably; and when the chair is moved from the second position to the first position, since the distance between the front end of the chair  30  and the pedals of the driving space S is shortest, so it is defined as a theft protection state (as illustrated in  FIG. 4 ). In the theft protection state the driving space S is reduced to minimum, to prevent thieves from entering the driving space, to provide the theft protection effect. 
         [0025]    Refer to  FIG. 6  and  FIG. 7 .  FIG. 6  is a schematic view illustrating the angular adjustment device in accordance with an embodiment of the present invention;  FIG. 7  is a schematic view illustrating the motion of the angular adjustment device in  FIG. 6 . 
         [0026]    The above said angular adjustment device  50 , adjusts the slant angle between the chair back  32  and the chair seat  31 , in accordance with the state of the chair driving structure  40 . The angular adjustment device  50  includes: a handle  51  connected to the chair seat by a pin-jointed structure, a gear  52  mounted to the chair back  32 , a meeting and parting structure  53  and a locking structure  54 . The front end of the handle  51  is extended out of the chair seat  31 , and the backend of the handle is mounted with a gear or a gear form bulge  511 . When the handle  51  is in a fixing state to limit the chair back  32 , the gear form bulge  511  is inserted into the gear  52 , to prevent the gear  52  from rotating, further to fix the slant angle between the chair back  32  and the chair seat  31 . When the handle  51  is in the released state, the gear form bulge  511  retreats from the gear  52 , so as to adjust the slant angle of the chair back  32 . In the released state, the chair back can rotate freely to adjust the slant angle. 
         [0027]    When the chair seat  31  is in the theft protection state, the meeting and parting structure  53  controls the chair back  32  to slant, so as to minimize the driving space S. In the present embodiment, the meeting and parting structure  53  at least comprises a first guide bevel  531 . The bevel  531  is provided to guide the handle  51  to move from the fixing state to the releasing state. When the chair seat  31  moves from the second position to the first position, the handle  51  is guided by the guide bevel  531 , to move from the fixing state to the releasing state. Then the chair back  32  via the elastic force of itself, rotates toward the direction of the front end of the driving space S to minimize the driving space S, so as to prevent thieves from entering the driving space. 
         [0028]    The meeting and parting structure  53  further comprises a second guide bevel  532 , to guide the locking structure  54 . When the locking structure  54  controls the chair back  32  in the theft protection state, it can rotate in only one direction to prevent thieves from rotating the chair back  32  in the opposite direction. The locking structure  54  is mounted at the slot part inside the chair seat  31 . The locking structure  54  includes an elastic part  541  and a small gear  542 . When the first guide bevel  531  guides the handle  51  to move from the fixing state to the releasing state, the small gear  542  is guided by the second guide bevel  532 , to gear into the gear  52 . Since the tooth shapes of the small gear  542  and the gear  52  are all ratchet shape, the small gear  542  can effectively limit the chair back  32  to rotate in only one direction, so as to prevent thieves from rotating the chair back  32  in the opposite direction, and to prevent thieves from entering the driving space S, to provide the theft protection effect. 
         [0029]      FIG. 8  is a schematic view illustrating the angular adjustment device in accordance with another embodiment of the present invention. The locking structure  54  may include: an inductor  55  and an electromagnetic switch  56  with a bolt  561  on it. When the chair back  32  rotates to a proper theft protection angle, the inductor  55  actives the bolt  561  on the electromagnetic switch  56 . The bolt  561  is then inserted in the through hole  521  on the gear  52 , to prevent thieves from rotating the chair back  32  in the opposite direction. 
         [0030]    In use, it can be combined to the electric theft protection device or center lock of the motor vehicle, to enable the driver to activate the driving motor  41  at the same time of leaving the driving space and locking the door of the motor vehicle. So the driving motor  41  moves the chair seat  31  from the initial position of the underside guide rail  43  between the second and third positions, to the first position of the front end. And at the same time, the handle  51  of the angular adjustment device  50  is guided by the first guide bevel  531 , moving from the fixing state to the releasing state. So the chair back  32 , via the elastic force of itself rotates toward the direction of the front end of the driving space S, to minimize the driving space S. Then the locking structure  54  locks the chair back  32 , to provide the theft protection effect. To cancel the theft protection effect, it is only needed to rotate the driving motor  41  in the opposite direction, to move the chair seat  31  from the first position to the position between the second and the third position of the backend. At the same time, since the handle retreats from the first guide bevel  531 , it is reset from the initial releasing state to the fixing state, so as to recover the driving space for the driver to sit in. 
         [0031]    Although the present invention has been described in detail with above said preferred embodiments, but it is only to make the people skilled in the art to understand the present invention, not to limit the scope of the invention. So, all the modifications and changes according to the characteristic of shapes or structures and spirit of present invention are involved in the protection scope of the invention.
A theft protection chair structure for motor vehicles for minimizing the driving space for the driver, includes: a chair having a chair seat and a chair back connected to the chair seat by a pin-jointed structure; a chair driving structure for driving the chair to go forward or backwards toward the driving space, to form a theft protection or a sitting state; and an angular adjustment device for adjusting the slant angle between the chair back and chair seat. When the chair driving structure is in a theft protection state, the angular adjustment device enables the angle between the chair back and chair seat to be an acute angle, then be locked and fixed. Thus, the theft protection effect is provided via the angular adjustment device and chair driving structure to reduce the driving space.