Abstract:
A back-up alarm for a motorized vehicle is disclosed comprising: a sounder having an audible emitter activated by an electrical signal input, and an electrical contact coupled to the input of the sounder and having electrical contacts to connect with a preexisting electrical socket to a trailer hitch mounted on a motorized vehicle.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention generally relates to a vehicle back-up alarm.  
         BACKGROUND OF THE INVENTION  
         [0002]    Back-up audio alarms are well known for use on vehicles. These alarms generally emit an audible series of repeated “beeps”, while a vehicle is in back-up mode. The alarm alerts persons standing behind the vehicle, who may be unaware that the vehicle is approaching them. Drivers of vehicles moving in reverse generally have difficulty in seeing persons standing behind their vehicle. Drives sometimes unknowingly and accidentally back-up towards a person standing behind their vehicle. Back-up alarms have been helpful in avoiding accidents and preventing injuries to people.  
           [0003]    Prior back-up alarms have been relatively difficult to install in vehicles. The alarms generally require a mechanic or a person with mechanical aptitude to install into vehicles. In addition, the back-up alarms tend to be relatively expensive. Ordinary vehicle owners often do not install back-up alarms on their vehicle due to the complexity of installation and the time required to install a conventional alarm. Accordingly, back-up audible alarms are not generally used for personal vehicles. Rather, they tend to be used on commercial and government vehicles such as large trucks, school buses and construction equipment.  
         BRIEF SUMMARY OF THE INVENTION  
         [0004]    There is a long-felt need for an easy-to-install and inexpensive backup audio alarm for vehicles. Preferably, the back-up audio alarm should be inexpensive and quickly installed by an ordinary vehicle owner. To ease the installation process, the back-up alarm electrical system should not require that the vehicle&#39;s electrical wiring be modified to connect to the back-up alarm. In addition, preferably the installation of the audio alarm should not require mechanical mounts to be attached to the vehicle that would harm the vehicle body or detract from the visual appearance of the vehicle body.  
           [0005]    In one embodiment the invention is a back-up alarm comprising: a sounder having an audible emitter activated by an electrical signal input, and an electrical contact coupled to the input of the sounder and having electrical contacts to connect with a preexisting electrical connector to a trailer hitch mounted on a motorized vehicle. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    [0006]FIG. 1 is a side view of an audible back-up alarm sensor;  
         [0007]    [0007]FIG. 2 is a side view of the alarm sensor shown in FIG. 1 wherein the sensor housing has been opened to show internal components and the electrical connector component has been separated for illustrative purposes;  
         [0008]    [0008]FIG. 3 is a plan view of a standard electrical trailer connector, and  
         [0009]    [0009]FIG. 4 is an enlarged view of a portion of a rear of a vehicle having a trailer hitch with a trailer hitch electrical connector wherein an alarm plug has been inserted in the electrical connector. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0010]    [0010]FIG. 1 is a side view of an exemplary alarm sensor plug  10 . The plug  10  includes an outer hollow housing having a tapered nose  12  and a cylindrical plug section  14 . The plug housing may be formed from the housing of a conventional electrical plug for a trailer receiver. The plug section  14  fits into a standard trailer hitch electrical socket  16  (see FIG. 13). The sensor plug is lightweight and can be fully mounted by installing it into the electrical trailer hitch socket  16  on a vehicle  18  having a trailer hitch or receptacle  17  for a trailer hitch (see FIG. 4). Insertion of the sensor plug  10  into the electrical trailer hitch socket  16  completes the installation of the alarm plug. No further mounting operations or electrical contact operation is needed to install the alarm plug on the vehicle. Once inserted into the hitch receptacle  16 , the alarm sensor plug  10  is ready to be used and will emit an audio alarm while the vehicle transmission is in reverse gear.  
         [0011]    As shown in FIG. 2, the sensor  10  has an internal piezo-sounder device  20 , including a speaker  22  that emits an audible alarm. The sounder is activate to emit the alarm when power is applied to the electrical contacts  24  of the sounder. The piezo-sounder is a commercially available, relatively-small and lightweight piezo-electric device that may be programmed emit a series of audible “beeps” when power is applied to the sounder&#39;s electrical contact  24 . The piezo-sounder is mounted in the body of the alarm sensor, such that it is protected from rain and other environmental elements.  
         [0012]    The audible beeps emitted by the sounder  20  are projected rearward of the sensor  10  and of the vehicle. These nose  12  of the housing is relatively transparent to audio signals. For example, a thin plastic housing may be used to form the nose  12 . In addition, a front circular surface  26  of the nose may be an open mesh covered by a web material to allow audio signals to broadcast rearward of the vehicle and to minimize the attenuation of the signal by the housing of the sensor.  
         [0013]    The nose  12  of the body may have winglets  28 . The winglets provide a finger grip to assist in the insertion and removal of the plug into the electrical socket.  
         [0014]    The audio alarm  10  includes an electrical connector  28  mounted in the body of the alarm. The electrical connector includes an electrical contact  30  which provides a conduit for electrical power to the power connector  24  of the piezo-sounder  20 . The electrical connector may also include an electrical ground connection  32  that provides an electrical contact for a ground connection  34  of the sounder. The electrical connector  28  of the audio alarm fits into the electrical contact of the trailer electrical socket receptacle  16 .  
         [0015]    The connector  28  has a power connector  34  that electrically connects to a power terminal  36  at the center of the electrical receptacle  16  of the trailer hitch. Similarly, the electrical connector  28  has a ground connector  38  that provides an electrical ground coupling between the sounder and a ground connector  40  on the trailer electrical receptacle  16 . The arrangement of power connector and ground connector (or other electrical connections) on the connector  28  of the alarm system is designed to match a standard electrical trailer hitch receptacle  16 .  
         [0016]    The seven-blade electrical connector  16  shown in FIG. 3 is one example of a standard electrical connector typically used with recreational vehicle (RV) vehicles in the United States. There are other types of trailer hitch electrical connectors that are commonly used in the United States and other countries. The electrical connector  28  of the alarm sensor may be designed to couple to other types of standard electrical trailer hitch connectors. The connector  28  may be designed to fit any one or more of the standard electrical connectors typically used with trailer hitches for motorized vehicles. These standard electrical connectors may include form standard electrical connectors on older vehicles, current standard electrical connectors such as the seven-blade connector, and future electrical standards developed for installation at the rear of vehicles.  
         [0017]    As shown in FIG. 4, an electrical trailer hitch receptacle  16  is generally mounted on the rear of the vehicle and faces rearward of that vehicle. By inserting the alarm plug  10  into the electrical receptor  16 , the plug also faces rearwardly of the vehicle. The insertion of the alarm plug into the electrical connector provides electrical power to the piezo-sounder by virtue of the connection of the power connector  34  and  36  on the plug and trailer electrical connector, respectively. Moreover, the sensor plug  10  is lightweight and small, such that the insertion of the sensor into the electrical socket receptacle  16  provides sufficient structural support to hold the alarm plug  10  onto the vehicle. A latch may be incorporated into the body of the sensor plug  10  to ensure that the plug does not inadvertently slide out of the trailer hitch electrical receptacle and to prevent theft of the plug when installed in the receptacle.  
         [0018]    In operation, the power connector  36  on the trailer hitch receptacle  16  is active, e.g., has 12-volt electrical power applied, only when the vehicle is in back-up mode. For example, when the driver of the vehicle moves the transmission of the vehicle into a reverse gear, the vehicle electrical system automatically applies power to the reverse power connection  36  of the trailer hitch electrical connector. In conventional practice, the reverse power connection  36  provides electrical power for back-up lights on a trailer hitched to the vehicle. However, in this application, the reverse power coupling is used to provide power to the sounder  20 , of the alarm plug  10  which is only applied when there is no attached trailer. When power is applied to the sounder at connection  24 , the sounder automatically generates and emits an audible alarm through speaker  22 . The audible alarm may be a series of high-pitched beeps that provide an audible warning to anyone standing behind the vehicle that the vehicle is backing up. When the vehicle is no longer in back-up mode, power is terminated to the power coupling  36  and the sounder stops emitting an audible signal because it is no longer being powered at terminal  24 . Accordingly, the alarm plug  10  emits an audible back-up alarm when the vehicle is in back-up mode, thereby causing power to be applied to the reverse alarm plug.  
         [0019]    The alarm plug  10  may be easily removed by being pulled out of the electrical receptor  16 . A lanyard  29  may be tied to the winglet  28  of the alarm body and also tied to the trailer hitch such that the alarm body may remain attached even when disconnected from the electrical socket  16 . The lanyard may include a lock to secure the alarm plug to the vehicle. The alarm sensor may be removed from the electrical socket  16  to allow a trailer to be mounted to the vehicle and the electrical connection plugged into the trailer hitch electrical socket  16  instead of the alarm sensor. While the back-up alarm is not available for use while a trailer hitch electrical connector is mounted in the electrical socket  16 , the instances in which a trailer is mounted on many vehicles is infrequent. Accordingly, it would be a relatively-rare instance in which the back-up alarm  10  would be removed from the electrical socket  16 . Thus, the alarm sensor  10  may be mounted in the electrical receptacle  16  of the trailer hitch during most vehicle operations. Moreover, the alarm sensor  10  may be intended for use on vehicles which routinely do not have trailers attached, and thus generally have an open trailer electrical socket  16 .  
         [0020]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.