Abstract:
Brake pressure indication apparatus in a vehicle includes a plurality of red L.E.D.s arranged in a ladder-like configuration. The L.E.D.s illuminate progressively in response to brake pressure. As brake pressure is increased, more L.E.D.s illuminate. Brake pressure may be sensed in either of two ways, such as movement of the brake pedal or the expansion of a flexible brake hose.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to vehicle brake lights and, more particularly, to vehicle brake lights having a plurality of lights with the lights illuminating in response to the degree of brake application pressure. 
     2. Description of the Prior Art 
     U.S. Pat. No. 4,682,146 (Friedman) discloses an indicator light system using a horizontally disposed tube filled with a rare gas. The gas tube is connected to turn signal indicators and the light in the tube propagates from either the left hand side of the tube or the right hand side of the tube, depending on the direction of travel of the vehicle. For a left hand turn, the light propagates from the right hand side progressively to the left hand side, indicating a left turn. For a right turn, the opposite happens. That is, the light propagates from the left side progressively to the right side. The apparatus is not degree-based responsive. 
     U.S. Pat. No. 5,606,310 (Egger et al) discloses a safety system in which a pair of lights illuminate when hard braking pressure is applied. A pressure transducer is used to sense the pressure of the brake pedal application. The system is coupled to the ordinary brake light system to provide different light effects depending on brake pressure applied. However, the light effects could be mistaken as a hazard warning light function. 
     U.S. Pat. No. 5,610,578 (Gilmore) discloses a light system indicative of pressure application on the brake system. Deceleration is sensed as well as brake pressure application. The brake illumination system provides brake light intensity as a function of the deceleration of the vehicle. The motion of the brake arm during braking is used as a determining element. This apparatus, like the &#39;310 (Egger) apparatus, utilizes the brake lights in an ordinary brake light system circuit. No additional lights or light elements are used. The apparatus is dependent on ambient conditions and bulb life to indicate intensity. Its is unclear how light intensity is translated into vehicle deceleration. 
     U.S. Pat. No. 5,682,137 (Li) discloses a safety system for vehicles which indicates acceleration and deceleration of the vehicle. The system utilizes inertial forces to determine acceleration and deceleration and sequentially activates lights in response to acceleration and deceleration. Red lights are used in response to deceleration, and green lights are used in response to acceleration. It will be noted that a problem with this system is that changes in the attitude of the vehicle will also cause changes of the sensitivity of the apparatus. That is, going uphill or going downhill which changes the attitude of the vehicle, will result false indications of acceleration or deceleration. The apparatus is also sensitive to vehicle loading changes which affect the attitude of the vehicle. 
     U.S. Pat. No. 5,831,523 (Lange) discloses a vehicle light system which uses a plurality of spaced apart light emitting diodes disposed about the rear window. Both red and yellow L.E.D.s are used with yellow L.E.D.s used as an adjunct to the directional indicators and red L.E.D.s tied into the brake system. The red L.E.D.s are activated when the brake light system is activated. The lights actuate sequentially, not in response to brake pressure. The red lights actuate sequentially as an indication that the brakes have been actuated, but they are not indicative of brake pressure. That is, the apparatus is independent of brake application intensity. The red L.E.D.s illuminate sequentially from the top center of the rear window outwardly and downwardly on the sides of the window. 
     The apparatus of the present invention utilizes red L.E.D.s or high intensity lamps or the like which illuminate sequentially in response to intensity of brake application pressure. That is, a ladder-effect of the red L.E.D.s occurs in direct response to brake pressure. Two embodiments are included, the first being an original equipment type installation and the second being an after market installation. 
     SUMMARY OF THE INVENTION 
     The invention described and claimed herein comprises a brake light system in which appropriate red lamps or L.E.D.s are sequentially illuminated in response to brake pressure application. The lamps are arranged in a ladder-like configuration and they illuminate successively in response to brake pressure. The brake light of the standard brake circuit is tied into the lamps. Two different types of sensors are used, one is a simple potentiometer responsive to movement of the brake pedal for original equipment installation and the second is an after market application in which a strain gauge sensor is used to sense brake pressure. The strain gauge sensor is tied to a flexible brake line, and the expansion of the brake line in response to increased brake pressure is used to cause an output in the strain gauge sensor. 
     Among the objects of the present invention are the following:
         To provide new and useful brake light apparatus;   To provide new and useful brake light apparatus having a plurality of red lamps;   To provide new and useful apparatus for indicating braking in a vehicle;   To provide new and useful apparatus indicating the intensity of brake pressure applied to a vehicle utilizing a plurality of red lamps;   To provide new and useful indicators of the intensity of application of brake pressure in a vehicle; and   To provide new and useful apparatus for sensing and indicating brake pressure application in a vehicle.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a schematic diagram of the apparatus of the present invention. 
         FIG. 2  is a side view schematically representing sensing apparatus usable with the apparatus of FIG.  1 . 
         FIG. 3  is a view in partial section illustrating sensing apparatus usable with the apparatus of FIG.  1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  comprises a schematic circuit diagram of brake pressure intensity indication system  10  of the present invention.  FIG. 1  includes three blocks, including a brake system measurement block  12 , a zero and gain amplifier block  42 , and an analog to progressive digital converter block  48 . A conductor  14  extends from brake system measurement block  12  to a conductor  16 . The brake system measurement block  12  is also connected to the zero and gain amplifier block  42  by a conductor  40 . The amplifier  42  is connected to the conductor  14  by a conductor  44 . The amplifier  42  is connected to the converter  48  by a conductor  46 , and the converter  48  is connected to the conductor  14  by a conductor  50 . The conductor  14  extends to a conductor  16  which extends to a conductor  18 . The conductor  18  extends through a brake switch  20  to a twelve volt power source  22 . 
     The switch  20  is a brake light switch associated with the brake pedal of a vehicle. Thus, when the brake is applied, the switch  20  closes, and the twelve volt current source  22  is then connected to the conductor  18  and through the conductors  16 ,  14 ,  44 , and  50  to the three blocks  12 ,  42 , and  48 . 
     A conductor  24  extends through a brake light  26 , and from the brake light  26  a conductor  28  extends to the vehicle ground  30 . A conductor  32  extends from the conductor  24  to the “other” vehicle brake light. 
     It will be recognized that the twelve volt current source  22 , the brake light switch  20 , and the conductors  18 ,  24 , lamp  26 , conductor  32  and ground  30  comprise the typical brake light circuitry. However, in the present invention, the conductor  18  also extends to provide electrical power to the brake measurement system  12  through the conductors  16  and  14 . The brake measurement system  12  provides an output on conductor  40  in response to the intensity of the brake pressure application. The output of the brake system measurement block  12  on conductor  40  is transmitted to the zero and gain amplifier  42  which in turn amplifies the signal and provides its output signal on conductor  46  to the analog to progressive digital converter block  48 . The analog to progressive digital converter system  48  in turn provides outputs on conductors to an array of lamps or L.E.D.s. It will be noted that in  FIG. 1 , L.E.D.s are indicated,  5  but it will be understood that any appropriate lamp may be used. The result is a ladder of lights, the numerically progressive illumination of which is indicative of the intensity of the brake pressure application. 
     Four levels of brake pressure indication are illustrated with eight conductors and lamps extending from the block  28 . For example, there are typically two brake lights on a vehicle. Conductors  60  and  64  extend from the block  28  to a pair of L.E.D.s  62  and  66 , respectively, which may illuminate as a conventional third brake light. Conductors  68  and  72  extend from the block  48  to a pair of L.E.D.s  70  and  74 , respectively, which, when illuminated, provide an indication of relatively low brake pressure intensity. Conductors  76  and  80 , which extend from the block  28  to a pair of L.E.D.s  78  and  82 , respectively, illuminate in response to a moderate intensity of brake pressure application. Conductors  84  and  88  extend from the block  28  to a pair of L.E.D.s  86  and  90 , respectively, and the illumination of L.E.D.s  86  and  90  then indicate a high intensity of brake pressure application. The respective L.E.D.s remain illuminated until the brake pressure is removed, thus providing a vivid visual indication of brake pressure intensity. 
     Obviously, there may be as many L.E.D.s utilized as desired. For example, the eight L.E.D.s illustrated may be configured in low vertical arrays, or ladders, on opposite sides of the rear window of a vehicle. An alternative may be to utilize the eight L.E.D.s as a single array on one side of the rear window and provide an additional eight in parallel on the opposite side of the rear window. 
       FIG. 2  comprises a schematic representation of the sensor elements usable with the apparatus of the present invention. There is shown the brake system measurement block  12  which includes within it a potentiometer, and an arm  110  is coupled to the potentiometer within the block  12 . The block  12  is appropriately secured to part of the vehicle chassis  2 . 
     Also secured to a portion of the vehicle chassis  2 , as is known and understood, is a brake arm  114  to which is secured a brake pedal  112 . The elements involved with the brake pedal  112  and its arm  114  have been omitted for purposes of clarity with respect to the present invention. 
     Depressing the brake pedal  112  causes movement of the brake arm  114 , and with it is movement of the actuating arm  110  of the potentiometer within the block  12 . The intensity of the pressure applied to the brake is, of course, measured by the movement of the brake arm  114 , and accordingly of the actuating arm  110 . The output of the potentiometer within the block  12  then provides the output as discussed above with respect to FIG.  1  and the blocks  42  and  48  to the L.E.D. array. 
     An alternate sensor system, as an after market application, is illustrated in FIG.  3 .  FIG. 3  illustrates, in partial section, sensor elements associated with a brake hose  160  for providing an output for the block  12  as illustrated in FIG.  1  and discussed above. 
     In  FIG. 3 , a clamp unit  130  is shown disposed about the brake hose  160 . The clamp unit  130  includes a bottom plate  132 , with a pillow  134  extending upwardly from the bottom plate. The hose  160  is clamped on the pillow  134 . A top plate  140  is spaced apart from the bottom plate  132  by a pair of posts  136  and  138 . The posts  136  and  138  are secured to the bottom plate  132  and the top plate  140  by bolts  150  and  154  and their respective nuts  152  and  156 . 
     The top plate  140  includes a recess  142  in which is disposed a strain gauge sensor  144 . A conductor  146  extends from the strain gauge sensor  144  to provide an output responsive to the brake pressure applied. The conductor  146  extends to the brake system block  12 . 
     The brake pressure applied will cause an expansion of the brake hose  160 . The expansion of the brake hose  160  is indicative of the intensity of the brake pressure applied. Accordingly, the output of the strain gauge sensor  144  will also be responsive to the intensity of the applied brake pressure. 
     Returning again to  FIG. 1 , when the switch  20  is closed, indicating that the brake pedal has been pushed, the vehicle brake lights, such as the lamp  26  and the second lamp, not shown, but provided with current from conductors  18 ,  24 , and  32 , the L.E.D.s  62  and  66  will also be illuminated. Depending on the intensity of the brake pedal application, additional pairs of L.E.D.s in the array will also be illuminated. Maximum intensity will illuminate all of the L.E.D.s in the array. 
     A pair of such L.E.D. arrays as illustrated in  FIG. 1 , and parallel with each other, and disposed on opposite sides of the rear window, for example, will provide a very noticeable indication to following drivers of the intensity of the brake application by the driver of the vehicle employing the apparatus  10 . 
     It will be understood that there may be as many L.E.D.s in an array as desired, or as practical for any particular illustration. The L.E.D.s in the array of  FIG. 1  are merely illustrative. 
     While the principles of the invention have been made clear in illustrative embodiments, there will be immediately obvious to those skilled in the art many modifications of structure, arrangement, proportions, the elements, materials, and components used in the practice of the invention, and otherwise, which are particularly adapted to specific environments and operative requirements without departing from those principles. The appended claims are intended to cover and embrace any and all such modifications, within the limits only of the true spirit and scope of the invention.