Abstract:
A motor vehicle safety system for a motor vehicle having wheels and tires on the wheels includes a hydraulically extendable elongate arcuate member in an elongate arcuate housing extending around an upper portion of each tires, and a valve operable in response to an impact on the impact sensor to apply hydraulic pressure from an oil supply system to the arcuate housing to displace the arcuate member along the arcuate housing from a retracted position in the arcuate housing to an extended position in which the arcuate member projects from the housing with an end located beneath the tire. Alternatively, the arcuate member may be released for displacement by gravity into its extended position. Rollers projecting from the arcuate member are in rolling engagement with the tire and with the ground on displacement of the arcuate member into the extended position.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to motor vehicle safety systems and, more particularly, to motor vehicle safety systems, which discontinue the driving of a vehicle by the wheels of the vehicle when the vehicle impacts against an obstruction, for example, a person or an object.  
         [0003]     2. Description of the Related Art  
         [0004]     In U.S. Pat. No. 1,604,752, issued Oct. 26, 1926, there is disclosed an automatic safety apparatus for automobiles, which has a transmission, including two gear trains for driving rear wheels of the automobile in opposite directions, and a double electromagnetic clutch for connecting one or the other of these gear trains to the rear wheels. This prior apparatus is such that, when the front of the vehicle impacts an object or person, one or more contacts on the front of the vehicle are closed, thereby operating a controller so as to operate the electromagnetic clutch to reverse the drive to the rear wheels.  
         [0005]     This prior apparatus, however, is complicated, bulky and expensive and, therefore, is impractical in a modern motor vehicle.  
         [0006]     U.S. Pat. No. 3,899,935, issued Aug. 19, 1975, discloses apparatus for automatically reversing or stopping the transmission of a vehicle on impact of the vehicle with a person or object. For this purpose, a sensor bar, mounted on the rear end of the vehicle, is deflected on impact with an object so as to tilt an end of an arm upwardly, thereby releasing a piston to move under the action of a spring. The piston pulls a cable, which, in turn, operates a transmission control panel to put the vehicle into reverse.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     It is an object of the present invention to provide a novel and improved motor vehicle safety system which, when installed on a vehicle, is unobtrusive and which interrupts contact between the tires of the vehicle and the ground when the vehicle impacts against an obstruction.  
         [0008]     According to the present invention, there is provided a motor vehicle safety system on a motor vehicle having front and rear wheels, with tires on the wheels, the motor vehicle safety system comprising an elongate arcuate housing extending around upper portions of the tires of at least one of the wheel pairs, with an extendable elongate arcuate member in the housing. The vehicle is also provided with an impact sensor which, in response to an impact, displaces the arcuate member along the arcuate housing from a retracted position in the arcuate housing to an extended position, in which the arcuate member projects from the housing and an end of the arcuate member is located beneath the tire. Rollers on this end of the arcuate member project from the arcuate member for rolling engagement with the tire and with the ground, and have axes of rotation extending transversely of the arcuate member.  
         [0009]     With this safety system, when the arcuate member is extended from the arcuate housing, in response to an impact on the impact sensor, the rollers on the arcuate member are interposed between the respective tires and the ground, so that the tires are no longer in fictional driving contact with the ground and, therefore, the vehicle is no longer driven forward.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The invention will be more readily understood from the following description of embodiments thereof illustrated, by way of example, in the accompanying drawings, in which:— 
         [0011]      FIG. 1  shows a diagrammatic view in side elevation of a motor vehicle equipped with motor vehicle safety devices according to a first embodiment of the present invention;  
         [0012]      FIGS. 2 through 5  show diagrammatic broken-away views of a front portion of the vehicle of  FIG. 1  with one of the motor vehicle safety devices of  FIG. 1  in four successive operational conditions;  
         [0013]      FIG. 6  shows a view in transverse cross-section through the safety device of  FIGS. 2 through 5 , taken along the line  6 - 6  of  FIG. 2 ;  
         [0014]      FIG. 7  shows a view similar to that of  FIG. 6 , but taken along the line  7 - 7  of  FIG. 2 ;  
         [0015]      FIG. 8  shows a broken-away view, taken in transverse cross-section along the line  8 - 8  of  FIG. 5 , through part of a vehicle tire and an end portion of a part of the safety device of  FIGS. 2 through 5 ;  
         [0016]      FIG. 9  shows a plan view of parts of the safety device of  FIGS. 2 through 5  in a retracted condition;  
         [0017]      FIG. 10  shows a view corresponding to that of  FIG. 9 , but with the safety device in an extended condition;  
         [0018]      FIG. 11  shows a view in side elevation, and partly broken away in cross-section, of of the safety device of  FIGS. 2-5 ;  
         [0019]      FIG. 12  shows a view taking in transverse cross-section along the line  12 - 12  of  FIG. 10 ;  
         [0020]      FIG. 13  diagrammatically illustrates a system including a sensor and associated components for operating the safety devices of  FIGS. 1 through 12 ;  
         [0021]      FIG. 14  shows a circuit with an impact sensor for releasing the arcuate member of  FIGS. 2-10   14  for displacement from its housing; and  
         [0022]      FIG. 15  diagrammatically illustrates a hydraulic system operated by a sensor which may be employed in place of the system shown in  FIG. 13  for operating the safety devices. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]     In  FIG. 1  of the accompanying drawings, there is diagrammatically illustrated a motor vehicle indicated generally by reference numeral  10 , which has a pair of front wheels, one of which is indicated by reference numeral  12 , and a pair of rear wheels, one of which is indicated by reference numeral  14 , each of the wheels being provided with a tire  15  and a respective arcuate housing indicated generally by reference numeral  16 .  
         [0024]     An impact sensor  18  is provided at the front of the vehicle  10 .  
         [0025]     As shown in greater detail in  FIG. 2 , each arcuate housing  16  contains an elongate, arcuate strip-shaped member  20  extending along the interior of the arcuate housing  16 , a closed end  22 , with an inlet  24  for hydraulic fluid communicating with the interior of the housing  16  adjacent, and an end  23  opposite from the closed end  22 .  
         [0026]     The arcuate member  20  has, at an inner end thereof, three pistons  26 , which are slidably received three arcuate cylinders  27  in the housing  16  so as to form three piston and cylinder devices for displacing the arcuate member  20  along the housing  16  in response to a supply of hydraulic fluid into the housing  16  through the fluid inlet  24 , which communicates with the cylinders  27 . The pistons  26  are connected to the trailing end of the arcuate member  20  by arcuate piston rods  29 , on which compression springs  31  are provided. The springs  31  act between the arcuate member  20  and the cylinders  27  to assist the displacement of the arcuate member  20 .  
         [0027]     As shown in  FIGS. 9 and 10 , the housing  16  is slightly tapered along the length of the housing  16  so that as the pistons  26  are displaced along the housing  16 , the arcuate member  20  eventually becomes wedged in the housing  16 , as shown in  FIG. 10 , and can no longer be displaced further along the housing  16  by the pressure of the hydraulic fluid and the action of the springs  31 .  
         [0028]     As can be seen from  FIGS. 6 through 10 , the arcuate member  20  is a strip-shaped member of curved cross-section, which at a first end  25  thereof is formed with a plurality of spikes  28 , which project from the arcuate member  20  toward the tread of the tire  15 .  
         [0029]     The end portion  26  also has rollers  30 , which have axes of rotation extending transversely of the arcuate member  20  and which project from opposite sides of the arcuate member  20 , i.e. from the side of the arcuate member  20  facing the tire  15  and from the opposite side of the arcuate member  20 , so that, on extension of the arcuate member  20  from its housing, into an extended position in which it is shown in  FIG. 5 , the rollers become interposed between the tread of the tire  15  and the ground, which is indicated by reference  32  in  FIG. 7 .  
         [0030]     The center of curvature of the arcuate housing  16  is offset from that of its respective wheel  12  to facilitate the correct guidance of the end  25  of the arcuate member  20  is guided toward the tread of the tire  15  as the end  25  approaches the ground  32 .  
         [0031]     Referring again to  FIG. 8 , the end portion  26  of the arcuate member  20  is also provided with an array of ball bearings  34 , the purpose of which is to prevent contact between the end portion  26  of the arcuate member  20  and the tread of the tire  15 . Further ball bearings (not shown) may be provided in the end portion  26  of the arcuate member  20  between the spikes  28  and the rollers  30 .  
         [0032]     The arcuate member  20  is made of a steel mesh core  33 , shown in a portion of the arcuate member  20  broken away in section in  FIG. 11 , which embedded in rubber and the arcuate member  20  is therefore semi-rigid but flexible.  
         [0033]     The operation of the above described embodiment of the invention is now described with reference to  FIGS. 2 through 10 .  
         [0034]     As illustrated in  FIG. 2 , the arcuate member  20  is normally located in a retracted position in the arcuate housing  16 . In this retracted position, the pistons  26  are located close to the fluid inlet  24  of the housing  16 .  
         [0035]     When the vehicle  10  impacts against an object, the sensor  18  is actuated, as shown in  FIG. 3 , to cause a supply of hydraulic fluid under pressure to be introduced into the housing  16  through the fluid inlet  24 .  
         [0036]     The inflow of hydraulic fluid into the housing  16  displaces the piston  26 , and therewith the arcuate member  20 , along the housing  16 , so that the end portion  26  of the arcuate member  20  is extended through the end  23  of the housing  16 .  
         [0037]     When the arcuate member  20  has been partially extended from the housing  16 , as illustrated in  FIG. 4 , the spikes  28  on the end portion  26  of the arcuate member  20  engage the tread of the tire  15 .  
         [0038]     Then, as illustrated in  FIG. 5 , the rollers  30  are drawn between the tire  15  and the ground  32 , so that the tire  15  is no longer in driving contact with the ground  32 , and in fact, the rollers  30  are rotated in a direction such as to cause the rotation of the tire  15  to tend to drive the vehicle  10  rearwardly. In this fully extended position, the pistons  26  are wedged in the housing  16  as mentioned above, and as illustrated in  FIG. 10 .  
         [0039]     As will be apparent, instead of tapering that the housing  16  to produce such wedging, it is alternatively possible to provided a stop (not shown) on the housing  16  for engaging a projection (not shown) on the arcuate member  20  to limit the displacement of the latter.  
         [0040]     As can be seen from  FIG. 6 , the underside of the arcuate housing  16 , at the forward end of the arcuate housing  16 , is formed with a longitudinally extending gap  35  to avoid obstructing the rollers  30  when the arcuate member  30  is in its retracted position.  
         [0041]     Referring now to a modified embodiment of the present invention illustrated in  FIGS. 11 and 12 , an elongate arcuate housing  116 , having a closed end  122  and an open opposite end  123 , contains an arcuate member  120 , which extends along the interior of the housing  116  and which, as shown in  FIG. 12 , is of transversely curved cross-section.  
         [0042]     The arcuate member  120  is connected to an outer tube  140 , which extends along the arcuate member  120 , and the arcuate tube  140  has a closed outer end  142  and an open inner end  144 .  
         [0043]     An inner tube  146 , which is fixed relative to the housing  116 , extends longitudinally along this outer tube  140  and has an open outer end  148  and a closed inner end  150 , adjacent to which a fluid supply inlet  152  communicates with the interior of the inner tube  148 .  
         [0044]     The arcuate member  120  has an outer end portion  126 , which is provided with spikes  128 , rollers  113  and ball bearings  134 , corresponding to the spikes  28 , the rollers  30  and the ball bearings  34  of the first-described embodiment of the present invention.  
         [0045]     In operation, hydraulic fluid is supplied under pressure through the fluid inlet  152 , in response to actuation of a sensor, and this hydraulic fluid forces the outer tube and, therewith, the arcuate member  120  along the arcuate housing  116  to interpose the rollers  130  between a vehicle tire and the ground, in a manner analogous to that described with reference to the first-mentioned embodiment of the present invention.  
         [0046]      FIG. 13  shows means for supplying the hydraulic fluid under pressure to the arcuate cylinder  27  in the housing  16  in response to the actuation of the sensor  18 , which means comprises an electrical switch (not shown) in the sensor  18  for completing a circuit from a battery  50  to open a valve V to connect the vehicle hydraulic system  52  to the hydraulic fluid inlet  24 .  
         [0047]      FIG. 14  illustrates a retainer device for retaining the arcuate member  20  against the action of the springs  31  prior to an impact.  
         [0048]     This retainer device has a stop member  40 , which projects into the housing  16  to form an abutment for the leading end of the arcuate member  20 . The stop member  40  is retractable, to release the arcuate member  20 , by means of a solenoid  42  connected to the stop member, an inertia switch  43  and a battery  44 . When the vehicle experiences an impact, an electrically conductive ball  45  in the inertia switch  43  is moved by inertia to interconnect a pair of contacts  46 , thereby causing energization of the solenoid  42  by the battery  44  to retract the stop member  40 .  
         [0049]      FIG. 14  shows a modified system for pressurizing the arcuate cylinders  27  in place of the apparatus shown in  FIG. 13 .  
         [0050]     In the system of  FIG. 14 , the senso  18  is connected throgh a power booster  60  of a type common in vehicle hydraulic brake systems. The power booster  60 , in reponse to operation of the impact sensor  18  when the vehicle experiences an impact, in turn operates a master cylinder  62  to supply hydraulic fluid from a fluid reservoir  64  through a combination valve  66 , also common in vehicle hydraulic systems, to the fluid inlet  24  of the arcuate cylinders  27  in the housing  16 .  
         [0051]     As will be apparent to those skilled in the art, various modifications may be made to the above-described embodiments of the present invention within the scope of the accompanying claims. For example, the present safety device could be provided only on the front pair of wheels of the vehicle, or only on the rear pair of wheels of the vehicle.  
         [0052]     A further possibility would be to use a pneumatic system, similar to those used for deploying air bags in vehicles, for extending the arcuate member from the arcuate housing  
         [0053]     Also, instead of employing only one impact sensor at the front of the vehicle, it is also possible to employ at least one sensor at each side and the rear of the vehicle for initiating the operation of the present motor vehicle safety device.