Abstract:
A system is disclosed for providing a backup power supply for a security gate system. In a preferred embodiment it includes a primary power supply, an AC motor and an auxiliary DC motor that share the same accessory devices including controller, movement mechanism, sensors, communication unit, etc. The auxiliary DC motor has its own independent DC power supply. If the primary power supply fails the auxiliary power supply takes over and moves the barrier between the open and closed positions as needed without interruption of service.

Description:
FIELD OF THE INVENTION 
   The present invention relates to security barrier systems that use motors to open and close the barriers and more particularly to a system that includes a backup power supply. 
   BACKGROUND OF THE INVENTION 
   Security systems that control access to a secure area are quite common. Gated communities, apartment complexes, office complexes and manufacturing facilities are among those that use such security systems to limit and control access. These security systems usually include one or more barriers, doors or gates that limit access into the protected limited access area. Theses systems typically include a mechanism to open and close the barrier that is driven by a motor. Generally, these motors are electrical and receive their power from the local power grid. In the event of a failure of the motor to function properly due to a malfunctioning of the motor or loss of electrical power from the local power grid, often the only alternative is to disconnect the barrier from the drive mechanism that connects it to the motor and open and close the barrier manually. Another alternative is to manually crank the barrier open or closed with a crank handle that inserts into a crank receptacle located on the motor drive shaft or some other shaft or pulley of the barrier movement mechanism. 
   Having to disconnect the barrier from the drive mechanism and manually open or close the barrier defeats the whole purpose for the security system, which is to provide an efficient and cost effective way to control access to the secure area. Correction of the problem may require service by a trained technician. Consequently, the barrier may not properly function for several hours to several days depending on how soon a properly trained service technician can be dispatched to the site of the malfunctioning barrier. 
   There are backup systems such as the DC1000 produced by Elite Access Systems and others, but they require separate input and output devices such as limit switches, loop detectors, safety sensors, alarm output devices, and other essential devices that must be duplicated separately and apart from the existing primary control system. 
   An additional problem with all existing backup systems is that they entail a breach of the security provided by the security system in order to have them function. In some cases it is even worse; the system ceases to function until it is repaired. 
   Thus, what is needed is a system and method for providing for opening and closing a security barrier without the need to provide redundant devices in order to maintain the integrity and safe operation of the system when the primary motive or power for the system stops functioning due a loss of electrical power or malfunctions for some other reason. Such a system would have to provide for a quick and efficient transfer from the nonfunctioning primary power source and motive force to a secondary power source and motive source. 
   SUMMARY 
   It is an objective of the present invention to provide a backup power supply and backup motive source to allow a movable security barrier to continue operation in an uninterrupted fashion if the primary power supply or motive force shall fail. It is a further objective to provide a backup power supply and motive source that do not require redundant accessory systems but that can use the same accessory systems. 
   The present invention accomplishes these and other objectives by providing a security barrier system with alternate power source, the system including: a) a security barrier movable between and open and a closed position; b) a mechanical apparatus for moving the barrier when the mechanical apparatus is engaged by an appropriate motive force; c) a primary motive source for engaging the mechanical apparatus to thereby move the barrier between an open and a closed position; d) a primary power supply to power operation of the primary motive source; e) a barrier controller operatively connected to the primary motive force to thereby control the movement of the barrier by controlling operations of the primary motive source; f) a secondary motive source operatively connected to the barrier controller and the secondary motive source being capable of engaging the mechanical apparatus; g) a secondary power supply to power operation of the secondary motive source; h) a sensor connected to the system for sensing failure of the primary power supply or motive force; and i) an activation device connected to the system, which upon receipt of a signal from the sensor indicating a failure of the primary power supply or the primary motive force activates operation of the secondary power supply and the secondary motive force, so that the controller can continue to control movement of the barrier without interruption. 
   In an additional aspect of one preferred embodiment the system of the present invention the primary motive source is an AC motor, the primary power supply is an AC power supply, the secondary motive force is a DC motor, the secondary power supply is a DC power supply. 
   In yet another aspect of the present invention the barrier controller, the sensor and the activation device all function on DC power and further including a converter to convert AC power from the primary power supply to DC power to power operation of the barrier controller, the sensor and the activation device and wherein when the primary power supply fails the barrier controller, the sensor and the activation device all receive power from the DC power supply. 
   In another variation of the present invention it can function with a sliding gate, a swinging gate, an overhead gate or a barrier gate. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood by an examination of the following description, together with the accompanying drawings, in which: 
       FIG. 1  is block diagram of the major functional components of the system of the present invention; 
       FIG. 2  is a raised perspective view of the primary and secondary power source and their connection to a portion of a sliding barrier movement mechanism; 
       FIG. 3  is a top view of a sliding gate security system that might employee the apparatus depicted in  FIG. 2 ; 
       FIG. 4  is a raised perspective view of the primary and secondary power source and their connection to a portion of a swinging barrier movement mechanism; 
       FIG. 5  is a top view of a swinging gate security system that might employee the apparatus depicted in  FIG. 4 ; 
       FIG. 6  is a schematic diagram of one version of a sensor/activator; and 
       FIG. 7  is a schematic diagram of another variation of a sensor activator. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The system and apparatus of the present invention would function as part of an overall security system that includes one or more barriers or security gates that limit access to a secure area. The actual opening or closing of the gate may be controlled by a guard located adjacent to the gate. Alternatively, access may be controlled by various automated systems in which a person arriving at the gate must input into a keypad an appropriate authorization code to open the gate. In another variation the person may have a transponder that sends a coded signal in response to a signal from a transceiver attached to the gate controller in a standard fashion. Upon receiving and decoding the signal from the transponder the gate controller would open the barrier or gate and allow access if the code received and decoded was an authorized one. The system may also include a phone located adjacent to the gate on which a person seeking entry can call a person or unit within the secure area with the authority to allow access by sending a gate open signal to the gate controller. 
   The system and apparatus of the present invention includes the functional components depicted in  FIG. 1 , a block diagram. The system includes a movable security barrier  21 , a movement mechanism  23 , such as a gear system a primary motive or movement source  25 , such as an AC motor a secondary or auxiliary motive or movement source  27 , a DC motor, a gate controller  29 , an AC current source  31 , and a DC current source  33 . A sensor/activator  39 , monitors operation of the system, in particular the AC power supply  31  and AC motor  25  and upon detecting a failure in either to operate, switches the system over to operation using the DC power supply  33  and auxiliary DC motor  27 . 
   Security gate systems as noted above typically also include communication systems  42  to allow for communication with persons within the secure area or direct communication with the gate controller to initiate opening of the gate or barrier  21 . This might be done by communication between a transponder in a vehicle seeking entry, not shown and a transponder in communication system  42 . The transponder in the vehicle sends a security code to the transponder in communication system  42 , which in turn signals the gate controller  29  to open the gate by using the AC motor  25 . Additionally, the system will have various safety devices  41 , and loop detectors  40 . Loop detectors  40  are placed on either side of the entry where the gate  21  is located, and provide the system with information on whether or not any vehicles are present in the area of gate  21 . Loop detectors  40  allow the gate controller or operator  29  to determine when it can safely open or close gate  21 . 
   In the preferred embodiment, gate controller  29  is a dedicated electronic system with a control board, and all of the peripheral devices necessary for it to function properly. Additionally, in the preferred embodiment gate controller  29  operates on DC power, which is supplied by the AC power supply, i.e. local public power transmission grid, . Naturally, the system includes an AC to DC converter to provide the appropriate DC current. If the system has to switch over to operation on DC power it can operate directly off DC power supply  33 . Additionally, in the Preferred embodiment the other subsystems, i.e.; loop detectors  40 , safety devices and communication system  42  operate on DC current so they can operate off of the AC power supply with appropriate conversion to DC current or directly off of the DC power supply  33   
   Security barrier  21  is a typical security gate, garage door or other similar barrier that is opened and closed on a selective basis to allow or deny access to those seeking entry into the secure area. Movement mechanism  23  would move barrier  21  between an open and a closed position. Movement mechanism  23  would in a preferred embodiment include a gearbox for translating the motive force to move barrier  21 . Movement mechanism  23  during standard operation would be driven by primary motive source  25 , an AC electric motor in the preferred embodiment; motor  25  would typically receive its electrical power from AC power source  31 , generally, the local public utility transmission grid. The system of the present invention also has a backup motive force, a DC motor  27  that receives its electrical power from an independent DC power supply  33  located adjacent to motor  27 . 
   Additionally AC to DC converter  30  converts the AC power received from power source  31  to DC power to run gate controller  29 , sensor activator  39 , safety devices  41 , loop detectors  40 , and the communications system  42 . AC power supply  31  also supplies main movement mechanism  23 , which in the preferred embodiment, is an AC motor. Thus, as is noted, elsewhere aside from the movement mechanism  23  the rest of the parts of the system run on DC power. 
   Gate controller  29  monitors the system and controls the over all operation of the system. As noted above, sensor/activator  39  monitors operation of AC motor  25  and AC power supply  31 . When sensory activator  39  detects a failure in the AC power supply  31  or AC motor  25  it will immediately switch the system over to operation with DC power supply  33  and DC motor  27 . 
   One of the distinct advantages of the system of the present invention is the fact that there are no redundant systems except for the two motive sources, AC motor  25  and DC motor  27 . Whether the system is operating on AC power and using the AC motor  25  to open and close barrier  21  or it is operating off of the DC Power  33  using DC motor  27  to open and close barrier  21 , all of the other systems depicted in FIG.  1  and described above are the same. Additionally, the system is designed such that it can operate for an extended period of time on DC power  33  and, with the DC motor  27 . As noted above the typical security gate system, if it has a backup DC motor for opening and closing the security gate, can only provide limited use, sometimes just opening the gate and no more, or require separate redundant systems, such as separate gate controller unit, etcetera. 
     FIG. 2  provides a perspective view of the major functional components of the present invention, configuration for a sliding gate, which include primary AC motor  45 , movement mechanism  43  a gear box, DC motor  47 , DC power supply  53  and gate controller  49 . All of these components are housed in frame  54 . 
   A noted above AC motor  45  obtains it electrical power from the local power grid, not shown. AC motor  45  provides the primary motive power for moving the gate or barrier between the open and closed position and visa versa. In the preferred embodiment depicted in  FIG. 2  belt  56  transfers rotational motion from pulley  58  of motor  45  to input pulley  60  of gear box  43 . In turn gear box  43  transfers that rotary motion to output pulley  62  that attaches to a chain, depicted in  FIG. 3 , that moves the barrier between the open and closed position. Gearbox  43  has appropriate gearing ratios within it to move the gate at an appropriate speed. Belt  57  connects to pulley  64  of DC motor  47  to pulley  60  of gearbox  43 . 
   During normal operation when AC motor  45  is providing the power to open and close the gate, DC motor  47  is not in operation and is not receiving DC power from DC power source  53 . DC power source  53  in the preferred embodiment is a rechargeable battery. In one version of the present invention DC motor  47  as it is being moved by belt  57  during operation of AC motor  45  charges DC battery  53 . As noted, in part above, gate controller  49  includes a CPU with memory appropriate software and related relays and other devices for monitoring and controlling the operation of AC motor  45  and DC motor  47 . As noted above gate controller  49  operates with DC power whether it is provided by the AC power source through an AC to DC current converter or it obtains DC current directly from the DC power supply. Thus, if controller  49  receives a signal to open the gate and AC motor  45  does not respond due to a loss of AC power or AC motor  45  malfunctions for some reason the sensor/activator  39  activates DC motor  47  which in turn moves belt  57  to turn pulley  60  of gear box  43  and thus open or close the gate as the case may be. The system thus can continue to operate in an uninterrupted fashion without any downtime or delay in opening or closing of the security gate. The system of the present invention maintains the integrity of the security system in allowing it to continue to function in an uninterrupted fashion. This arrangement eliminates the need for redundant movement mechanisms for each power supply since both motors share the same apparatus for transferring power for movement of the barrier. 
   In the preferred embodiment of a sensor/activator, the device is a micro-controller system consisting of a voltage monitor sensing the output of the AC converter. The voltage monitor consists of a resistive divider whose output is digitized through an analog to digital converter. The analog to digital converter can be a separate device or integrated with the micro-controller itself. Upon sensing a loss of power from the AC converter, the micro-controller switches the motor drive commands form the AC motor  45  to DC motor  47  and switches the power supply from the AC power source to the DC power source  53 . Alternatively, the sensor/activator could be comprised of discrete logic to accomplish the switching functions. 
   The apparatus depicted in  FIG. 2  is designed to move a sliding barrier as depicted in FIG.  3 . In  FIG. 3  the entire apparatus depicted in  FIG. 2  is enclosed in exterior housing  70  with only output pulley  62  projecting outside of exterior housing  70 . Pulley  62  is connected to chain  72  that in turn attaches to gate  74  and when pulley  62  turns it either moves gate  74  by movement of chain  72  from an open position  75 , shown in outline, to a closed position  76  and visa versa. Naturally, as explained above the system can do this with power provided by either AC motor  45  or DC motor  47  depending on the circumstances. 
     FIG. 4  depicts a version of the present invention designed to work with a swinging gate. In  FIG. 4  all of the aspects of the invention that are the same as that depicted in  FIG. 2  are numbered the same and the commentary on that particular feature is the same. In fact the only substantial difference between the FIG.  2  and  FIG. 4  is that gearbox  83  has a rotating cam  82  extending out of its top instead of a pulley extending from its side. Naturally, gearbox  83  has a different gearing structure located within its interior than gearbox  43 . However, such gearboxes,  43  and  83 , are well known in the art and need not be discussed further with respect to their interior structure for a proper understanding of how the invention works.  FIG. 5  is an overhead view of a swinging security gate. The entire apparatus depicted in  FIG. 4  is depicted in  FIG. 5  enclosed in housing  90  with the exception of rotary cam  82  that projects out of the top of housing  90 . As depicted in  FIG. 5  cam  82  and its arm  94  connect to gate  96 . Arm  94  has a joint  97  that allows arm  94  to bend or jackknife as cam  82  rotates and thereby by moves gate  96  from a closed position  98  to a an open position, shown in outline,  99  and then move back to the closed position  98 . 
   Controller  49  can be programmed to periodically test the backup DC motor  47  and DC battery  53 . Additionally, controller would include a DC battery charger and would monitor the charge on DC battery  53  to assure it is properly charged at all times. 
     FIG. 6  provides a schematic type of block diagram of one variation of the sensor-activator of the present invention. Sensor activator  104  connects to AC-DC power converter  114 . As can be seen, AC-DC power converter  114  receives power in the form of AC current from local power grid  108  and converts to DC current. AC power is provided directly over lines  109  through to the primary controller  111  to AC motor  110 . The sensor-activator of the present invention is a relay type of switch  104 , and it connects to DC control logic unit  106 . DC control logic in turn connects to DC power supply  120  as well as to DC motor  25 . DC control logic unit  106  also connects to the primary controller  111 . DC power is provided to the primary control unit over lines  115  and  116 . Diodes  117  and  118  limit the flow of power in one direction on the two lines to which they form a part. Relay switch  104  upon a loss of power at AC-DC power supply  114  changes state, which in turn generates a signal. The signal, generated by relay swithch  104  signals DC control logic  106  that there has been a loss of power at the AC-DC power converter  114 . DC control logic  106  then immediately switches operation over to DC power  120 , which provides power to all of the components. DC control logic  106  is a standard control system that will activate DC power supply  120  on receipt of the signal indicating a loss of power at AC-DC power converter. 
     FIG. 7  provides another variation of a sensor-actuator that could be used with the present invention. In  FIG. 7 , the same components that appear in  FIG. 6  are given the same number. The version depicted in  FIG. 7  includes a micro-controller  147 , appropriately programmed, resistor network  131  comprising of resistors  133 , and  135  that together form the sensor actuator  134 . Sensor activator  134  replaces the relay mechanism, and DC control logic of FIG.  6 . Referring back to  FIG. 7 , when a loss of power occurs at the AC to DC converter  114 , the resistor network  133  and  135  indicate a change of state that is received by micro controller  147  at inputs  138  and  137 . Upon receiving indication of the change of state of resistors  133  and  135  at input points  137 , and  138  Microcontroller  147 , immediately switches on power from DC power supply  120 , which, thereby, allows continued operation of the system with DC motor  125 , and all of their components that operate under DC power. Microcontroller  147  can be any standard type of microcontroller that can be programmed to perform the appropriate switching function control use of DC power supply  120 . 
   While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made to it without departing from the spirit and scope of the invention.