Patent Publication Number: US-2023158997-A1

Title: Method and apparatus for preventing theft of catalytic converter

Description:
I. BACKGROUND 
     A. Technical Field 
     This invention generally pertains to the field of antitheft devices. This invention specifically pertains to the field of electronic antitheft devices provided to deter or prevent theft of a catalytic converter in an automobile or SUV. 
     B. Description of Related Art 
     Catalytic converters are used in the exhaust systems of automobiles for the purpose of improving air quality by reducing toxic emissions, including carbon monoxide, unburnt hydrocarbons, and nitrogen oxide compounds by chemically catalyzing the emissions into common compounds such as carbon dioxide and water. Catalytic converters can include precious metals such as platinum, palladium and rhodium which are effective catalysts for producing the catalyzing reaction. 
     Because of the precious metals, catalytic converters are very expensive, making them the target of theft. Thus, there is a general need to protect automobiles from catalytic converter theft. This need is especially great at outdoor lots of automobile dealerships, where many vehicles are closely accessible and especially vulnerable to theft at nighttime, enabling the thieves to procure several catalytic converters at a time before detection by police or security. 
     Mechanical devices are known for protecting catalytic converters from theft. One such known device is “The Cat-Lock” sold by Monat Technologies. Such mechanical devices are based on the premise of surrounding the catalytic converter with a locked steel structure which is difficult or impossible to penetrate, and which can include an impervious steel cable for securing the catalytic converter to the vehicle frame. 
     While such mechanical deterrents are effective, they are expensive and thus can be cost-prohibitive for deploying with multiple vehicles, especially at an automobile dealership where hundreds of vehicles are present. Other schemes are known for protecting catalytic converters, but these also tend to be complicated and thus expensive. There is therefore a need for an inexpensive and effective deterrent to catalytic converter theft. 
     II. SUMMARY 
     Provided in this disclosure is an antitheft system including a wire loop for completing the electrical circuit. One or more securing components are provided for securing some or all of the wire loop in contact with the device(s) to be protected. In one aspect of the present invention, the device to be protected can be an automotive catalytic converter and wherein the securing component(s) can be one or more fixed clamps for securing some portion or the entirety of the wire loop alongside a vehicle exhaust system including the catalytic converter. 
     A monitoring circuit is provided in electrical communication with the wire loop, for monitoring the electrical circuit monitored by the wire loop. A detector circuit is connected to the monitoring circuit, for detecting a discontinuity in the electrical circuit indicative of a disconnection or separating of the wire loop(s). An alarm circuit is connected to the detector circuit, for activating an alarm upon detection of the discontinuity in the electrical circuit. 
     The present antitheft system further includes a key-activated arming circuit having a key detection circuit for detecting a key insertion signal indicative of insertion of a removable key. The arming circuit also includes a wire loop detection circuit for detecting a wire loop(s) insertion signal indicative of insertion of the wire loop corresponding to establishment of the electrical circuit. The arming circuit also includes a control logic circuit which: 1) receives the key insertion signal from the key detection circuit, 2) subsequently receives the wire loop(s) insertion signal from the wire loop detection circuit, and 3) subsequently arms the arming circuit. An alarm deactivation circuit is also included for receiving a second key insertion signal from the key detection circuit and deactivating the alarm circuit to disable the alarm. In a preferred embodiment, the key detection circuit includes a key switch, actuated by insertion of the key, to produce the key insertion signal. 
     As a special feature, the present removable key includes a shaft and the key detection circuit cooperates with a socket, mounted onto an exterior of a housing, for receiving the shaft of the removable key. Furthermore, the wire loop includes a coaxial plug for electrically connecting respective two ends of the wire loop(s). The wire loop detection circuit cooperates with a coaxial socket, mounted onto an exterior of a housing, for receiving the coaxial plug of the wire loop. The present antitheft system also includes a test circuit comprising a user-actuated switch connected to the alarm circuit, for test activating the alarm. Also, the alarm preferably includes a sound transducer for generating an audible alarm signal. 
     According to one aspect, the present antitheft system provides an electronic deterrent to the theft of catalytic converters. 
     According to another aspect, the present antitheft system is inexpensive and thus cost-effective for deploying with multiple vehicles. 
     According to an additional aspect, the present antitheft system is uncomplicated while remaining an effective deterrent to catalytic converter theft. 
     Other benefits and advantages of this invention will become apparent to those skilled in the art to which it pertains upon reading and understanding of the following detailed specification. 
    
    
     
       III. BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosed antitheft system may take physical form in certain parts and arrangement of parts, embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein: 
         FIG.  1    is a block diagram generally depicting components of the present antitheft system in accordance with an exemplary embodiment. 
         FIG.  2    is a high-level representation of the installation of the present antitheft system in a vehicle in accordance with an exemplary embodiment. 
         FIG.  3    is a schematic view depicting an alarm module with components in accordance with an exemplary embodiment. 
     
    
    
     IV. DETAILED DESCRIPTION 
     Referring now to the drawings wherein the showings are for purposes of illustrating embodiments of the article only and not for purposes of limiting the same, and wherein like reference numerals are understood to refer to like components: 
       FIG.  1    generally depicts an antitheft system  10  in accordance with an exemplary embodiment. A wire loop  12  is provided for conducting an electrical current to establish an electrical circuit. It is to be appreciated that the wire loop  12  is a wire having two ends that connect to the antitheft system  10  and looped over to produce a return wire having two portions that can be run concurrently together. In one aspect, in some implementations for use with parked vehicles, not to be operated at normal driving temperatures, the wire loop  12  can be a common, non-heat-or-weather-resistant coaxial cable having a looped end. In another aspect, in other implementations for use with driven vehicles, the wire loop  12  can be a weather-resistant, metal-clad return wire that can withstand temperatures up to 2800 degrees Celsius, such as might be encountered in close contact with an active automotive exhaust system. As shown in  FIG.  2   , the end of the wire loop  12  can include an end cap  12   a , which could be formed of an adhesive bead, to define a terminal longitudinal extent of the return wire. 
     With further reference to  FIG.  1   , the antitheft system also includes one or more securing components  14  for securing some portion or the entirety of the wire loop  12  in contact with a device  16  to be protected from theft. In the preferred embodiment, as additionally depicted in  FIG.  2   , the device  16  to be protected can be an automotive catalytic converter, and the securing component(s)  14  can be one or more clamps for securing the wire loop  12  (or a portion thereof) alongside and adjacent to exhaust pipes  16   a  of a vehicle exhaust system including the catalytic converter  16 . The clamps  14  are preferably looped around the tubular circumference of the exhaust pipes  16   a  with the wire loop  12  sandwiched between the clamps  14  and the catalytic converter  16 . 
     As generally indicated in  FIGS.  1  and  2   , the clamps  14  are mounted snugly in close proximity with the ends of the catalytic converter  16  in a substantially abutting relationship, so as to not allow any gap between the clamps  14  and the converter  16 . In this manner, any attempt to cut free the catalytic converter  16  (such as with a reciprocating saw, i.e., a “sawzall” or portable band saw) will result in severing the wire loop  12 , thereby triggering the alarm (as explained in detail hereinbelow). Other clamps  14  can be placed circumferentially around the exhaust pipes  16   a , along the longitudinal extent of the exhaust pipes  16   a , in order to secure the wire loop  12  into close contact with the exhaust system. 
     As depicted in  FIG.  2   , the wire loop  12  is configured to run along the exhaust pipes  16   a  to enter into the engine compartment. An alarm module  20  can be retained in engine compartment of the vehicle, secured under the hood of the vehicle, preferably mounted to the side of the firewall  18  within the engine compartment. The alarm module  20  can be powered by the vehicle battery or by an independent battery. The wire loop  12  is then plugged into the alarm module  20  to implement the operation of the antitheft system  10 . 
     As illustrated generally in  FIG.  1   , the antitheft system  10  includes a monitoring circuit  22 , in electrical communication with the wire loop  12 , for monitoring the electrical circuit established in the wire loop  12 . This monitoring is performed to observe whether an unbroken current path is maintained through the wire loop  12 , indicative of normal operation. A detector circuit  24  is connected to the monitoring circuit  22  for detecting a discontinuity in the electrical circuit indicative of a disconnection of the wire loop  12 , as would occur in the event that the wire loop  12  is either severed during a theft attempt or unplugged in an attempt to circumvent and defeat the antitheft system  10 . The discontinuity or current in the wire is detected by a control logic circuit (described in detail hereinbelow) with the result of no ground detected, which activates an audible alarm. The control logic circuit continuously verifies the continuity of the wire. Once activated, the alarm will continue to sound until the module is disabled, for example, by insertion of a key. 
     An alarm circuit  26  is connected to the detector circuit  24  for activating an alarm upon detection of the discontinuity in the electrical circuit indicative of severing the wire loop  12  in a theft attempt. A suitable alarm is issued upon activation, as will be explained in detail hereinbelow. 
     With particular reference to  FIG.  3   , the present antitheft system  10  also includes a key-activated arming circuit  30  including a key detection circuit  32  for generating a key insertion signal indicative of insertion of a removable key  34 . In one aspect, the key detection circuit  32  can be a key switch, actuated by insertion of the key, to generate the key insertion signal. The present system  10  also includes a wire loop detection circuit  36  for generating a wire loop insertion signal indicative of insertion of the wire loop  12  corresponding to establishment of the electrical circuit. 
     With continuing reference to  FIG.  3   , the arming circuit  30  also includes the aforementioned control logic circuit  38  which:
         1) receives the key insertion signal from the key detection circuit  32 ,   2) subsequently receives the wire loop insertion signal from the wire loop detection circuit  36 , and   3) subsequently arms the arming circuit  30 .
 
The control logic circuit  38  can include processing circuitry to detect the order in which the signals are detected, that the key insertion signal is received first, followed by the wire loop insertion signal, so that the arming circuit  30  is only armed after these signals are received in this correct order. The arming circuit  30  is in communication with the monitoring circuit  22  so that the arming circuit  30  is only armed and activates the monitoring circuit  22  after the aforementioned signals are received in the correct order as indicated hereinabove.
       

     With further continuing reference to  FIG.  3   , the present antitheft system  10  also includes an alarm deactivation circuit  40  for receiving a second key insertion signal from the key detection circuit  32  and deactivating the alarm circuit  26  to disable the alarm. In the event that the alarm is activated in the event of a theft attempt, the removable key  34  is inserted again, which generates another key insertion signal which is interpreted by the system  10  as a deactivation signal, thereby disabling the alarm. 
     With reference to  FIGS.  2  and  3   , the removable key  34  has a shaft  34   a , preferably elongated and cylindrical. The key detection circuit  32  is configured to cooperate with a socket  34   b , which is mounted onto an exterior of a housing (i.e., of the module  20 ). In this way, the socket  34   b  is configured for receiving the shaft  34   a  of the removable key  34 . Similarly, the wire loop  12  is configured to terminate with a coaxial plug  12   b  for electrically connecting respective two ends of the wire loop  12 . The wire loop detection circuit  36  is configured to cooperate with a coaxial socket  12   c , mounted onto an exterior of the housing (i.e., the module  20 ), for receiving the coaxial plug  12   c  of the wire loop  12 . 
     With ongoing reference to  FIG.  3   , the antitheft system  10  also includes a test circuit  42 , including a user-actuated switch  44 , where the test circuit  42  is connected to the alarm circuit  26 , to enable a user to selectively for test activate the alarm. In one aspect, the switch  44  can be connected to a button mounted on the outside of the module  20 , where pressing the button activates the alarm. In one aspect, the alarm preferably includes a sound transducer  46  for generating an audible alarm signal, which can deter a prospective thief from stealing the converter  16 . However, depending on the desired implementation, the alarm can additionally or alternatively include a wireless connection to a network node which can transmit a signal which can, in turn, generate an audible and/or visual indicator observed in a remote location, such as a security office or police station. Further, the alarm can also optionally be armed using a key fob associated with the vehicle. 
     In the preferred embodiment, the present antitheft system  10  and the electronic circuits and components described hereinabove can be retained in the module  20 , which is preferably a small box formed of plastic. A common type C battery can be used to power the system  10 . However, the system  10  can be alternatively wired to receive power from the vehicle battery. Further, at least some of the present components for each vehicle can alternatively be distributed and located elsewhere as part of a networked antitheft distributed system, along with other similar components for other vehicles, all without departing from the present invention. In the preferred embodiment, the electronic circuits and components described hereinabove can be analog or digital circuits and components preferably mounted on one or more printed circuit boards and retained in the module  20 . However, it is to be appreciated that at least some of the electronic circuits and other components described hereinabove can be alternatively implemented as software components in a computer system, all without departing from the present invention. 
     Numerous embodiments have been described herein. It will be apparent to those skilled in the art that the above methods and apparatuses may incorporate changes and modifications without departing from the general scope of this invention. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof.