Patent Publication Number: US-9406207-B2

Title: Chain driven gate and security system

Description:
RELATED APPLICATIONS 
     The present application is a continuation of U.S. Provisional Patent Application Ser. No. 61/969,659 filed on Mar. 24, 2014. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to automated gates. More specifically, the present invention relates to a security system for chain driven automated sliding gates. 
     Automated gates are ubiquitous in present day to society to control access to secure areas. Automated gates are openable and closable upon a predetermined trigger, such as an open command, a close command, or based upon predetermined dates and times. Most commonly, automated gates are used at the entrance to a facility and are used to control pedestrian or vehicular access on and off the location. For example, homes and office facilities may employ an automated gate at their main entrance. All persons and vehicles entering and exiting the facility are directed through the automated gate. Automated gates are also used at interior locations within a facility. For example, automated gates are used within parking garages to provide protection to parked cars. 
     Automated gates typically include two components, namely the gate and the gate operator. The gate is a physical structure that is moved to block a portal through which persons or vehicles ingress or egress. Most gates used in commercial applications are made of wood or metal, and may or may not include various decorative features. Meanwhile, the gate operator is the machinery that moves the gate from an open condition to a closed condition, or vice versa. Typically, gate operators are electrically powered and include a motor, a drive mechanism, and a processor for selectively activating the gate operator. Typically, the gate operators are chain driven, gear driven or hydraulic driven. 
     Common gates used for automated gates include the slide gate, the cantilever gate, the swing gate, the vertical lift gate, the vertical pivot lift gate, the bi-folding gate, and the barrier arm gate. The present application is believed to have application to any of these gates where the gate operator employs a length of chain to open and close the gate. 
     The most common type of automated gate is the slide gate. The slide gate is mounted parallel to the inside of a wall, fence or barrier and slides horizontally back and forth across a portal or opening through which persons or vehicles will pass. The slide gate includes rollers to support it. These rollers typically roll upon a metal track that has been installed along the ground across the gate opening. For this reason, slide gates are sometimes referred to as “rolling gates” or “track gates”. 
     Typically, the gate operator includes a chain drive for moving the gate back and forth. The chain drive includes a length of chain which affixes to the gate. Moreover, the chain drive includes a motor having a sprocket gear wherein the teeth of the gear mesh with the holes in the links of the chain. Activation of the motor, and in turn rotation of the gear, causes the chain to pull the slide gate in one direction or another. Chain drive mechanisms typically include a processor and sensors for determining whether the gate has opened or closed completely so as to timely deactivate the motor. 
     Advantageously, the gate is effectively locked in place if the motor has been deactivated and rotation of the sprocket gear has been rotationally locked so to prevent pulling of the chain or movement of the gate. 
     Unfortunately, thieves and trespassers have discovered that the security provided by the gate can be easily overcome by simply cutting the chain. Once the chain has been cut, it will fall, thereby allowing the chain to disengage from the motor&#39;s sprocket and enable one to simply manually slide the gate from a closed condition to an open condition. Trespassers can then simply walk or drive through the previously closed portal. 
     Accordingly, there is a need for an improved security system for chain driven gates. 
     In addition, it would be advantageous to provide a security system for a chain driven gate which activated an alarm in the event that the chain had been cut. 
     Moreover, it would be advantageous to provide a security system for a chain driven gate that did not require substantial additional hardware and software. 
     SUMMARY OF THE INVENTION 
     The present invention addresses the aforementioned disadvantages by providing an improved chain driven gate and security system. The system includes a gate for selectively blocking an opening. The gate may be constructed in any form as can be determined by one skilled in the art so as to have a size sufficiently large to obstruct passage of persons or vehicles through the intended passageway. Typically, it is believed that the gate will be relatively thin and rectangular so as to have a top, a bottom, and opposing side edges. Preferably, the gate includes wheels for allowing the gate to easily slide upon a track within a groove, or includes another construction for reducing friction as the gate moves. Furthermore, the gate may be made of any material commonly used for constructing a gate including iron, chain link, wood slats, etc. 
     The chain driven gate and security system also includes a gate operator for opening and closing the gate. The gate operator includes a length of chain made up of individual links. The chain has first and second ends affixed to the gate. Preferably, but not necessarily, the first end of the chain is affixed towards a left edge of the gate and the second end of the chain is affixed toward the right edge of the gate. The gate operator includes a motor having a toothed sprocket for receiving the individual links of the chain such that activation of the motor and rotation of the sprocket causes the chain to be pulled in one direction or another so as to open or close the gate. 
     The gate and security system includes a sensor for detecting whether the chain has been severed. In a preferred embodiment, the sensor includes a magnet affixed to a predetermined location upon the chain. Furthermore, the sensor includes a magnetic field detector for determining whether the magnet is adjacent to it. To this end, the magnetic field detector may be simply a simple magnetically activated switch which is activated upon a magnet being nearby. The magnet is affixed to the chain and positioned so as to be adjacent to the magnetic field detector when the gate is in a closed condition. Preferably, the magnet affixed to the chain performs two functions. First, the magnet and magnetic field detector can be utilized as a signal that the gate has traveled from an open condition to a closed condition so as to trigger deactivation of the motor. Secondly, the magnet and magnetic field detector can be utilized to determine whether the chain has been cut, as cutting the chain will release the tension in the chain which maintains the magnet adjacent to the magnetic field detector. Accordingly, cutting the chain causes the magnet to fall away from the magnetic field detector so as to be capable of indicating a potential theft or trespass is being initiated. 
     The chain driven gate and security system of the present invention further includes an alarm for producing a visible or audible alarm. Various visible or audible alarms can be determined by those skilled in the art. For example, the alarm may include a high pitched siren and/or a flashing light which immediately indicate that the condition has occurred. Alternatively, the alarm might be simply a visual indication upon a computer screen or creation of a computer record identifying that an event has occurred. 
     A processor is provided which is connected to the gate operator&#39;s motor, sensor, and alarm. The processor controls the opening and closing of the gate. To this end, it is connected to switches, RF receivers or buttons so as to receive a signal so as to trigger the opening or closing of the gate. In addition, the processor is connected to the sensor so as to deactivate the motor when it has been sensed that the gate has completely opened or completely closed. Moreover, the processor is connected to the sensor which detects whether the chain has been severed. In the event that the chain has been severed, the processor activates the alarm. In the event that the chain has been severed, preferably the processor also deactivates operation of the motor since operation of the motor with a severed chain could cause damage to the entire system. 
     Accordingly, the security system for chain driven gates of the present invention is greatly improved compared to prior security systems. 
     Advantageously, the security system for chain driven gates activates an alarm in the event that the chain has been cut. In addition, the security system does not require substantial additional hardware and software. 
     Other features and advantages of the present invention will be appreciated by those skilled in the art upon reading the detailed description which follows with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating a gate assembly of the present invention; 
         FIG. 2  is a side view illustrating the motor chain and a sensor for use with the gate and security system of the present invention; 
         FIG. 3  is a side close-up view illustrating a chain and sensor for use with the gate and security system of the present invention; 
         FIG. 4  is a side cut-away view illustrating a chain and sensor of the gate and security system of the present invention wherein the chain has been severed; 
         FIG. 5  is a perspective view of a second embodiment of a gate and gate operator for use with the gate and security system of the present invention; 
         FIG. 6  is a side cut-away view illustrating the chain and sensor arrangement for opening the gate illustrated in  FIG. 5 ; 
         FIG. 7  is a second cut-away view illustrating the chain and sensor arrangement of  FIGS. 5-7  wherein the chain has been severed; and 
         FIG. 8  is a block diagram illustrating the gate and security system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the present invention is susceptible of embodiment in various forms, as shown in the drawings, hereinafter will be described the presently preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the invention, and it is not intended to limit the invention to the specific embodiments illustrated. 
     With reference to  FIGS. 1-8 , the chain driven gate and security system  6  of the present invention includes a gate  3  and gate operator  15 . As represented in  FIGS. 1 and 6 , the gate can be constructed in innumerable forms so as to block a portal  11  such as a driveway or a walkway. The gate  3  includes a first edge  5  and a second edge  7 . Preferably a track  9  is provided upon which the gate slides. As reflected in the figures, the track  9  may be positioned below the gate. However, the track may also be positioned above the gate, such as where the gate includes rollers at the gate&#39;s top for rolling upon an overhead track (not shown). 
     The gate operator  15  controls the movement of the gate  3  so as to slide in a first direction so as to open the portal  11  or so as to slide the gate in a second direction so as to close the portal  11 . For example, as illustrated in  FIGS. 1 and 6 , the movement of the gate  3  in a right direction causes the portal to open, while movement of the gate in the left direction causes the portal to close. The gate operator includes a chain  17  comprised of individual links. The chain  17  includes a first end  19  and a second end  21  which are both affixed to the gate. In a first embodiment illustrated in  FIG. 1 , the chain&#39;s first end  19  is affixed to the gate towards the gate&#39;s first edge  5  and the chain&#39;s second end  21  is affixed towards the gate&#39;s second edge  7 . However, the gate  3  and security system of the present invention do not require this particular construction. For example,  FIG. 6  illustrates an embodiment wherein both ends of the chain  17  are affixed toward the first edge  5  of the gate  3 . Other gate and chain assemblies can be determined by those skilled in the art. 
     As illustrated in the figures, the chain operator  15  includes a motor  25  having a toothed sprocket  27  for engaging the links of the chain  17 . Activation of the motor and the corresponding rotation of the toothed gear  27  causes the chain to be pulled so as to slide the gate in one direction or the other. Additional gears  29  may be provided to provide proper tensioning, orientation and alignment of the chain  17 . 
     The gate and security system  1  of the present invention includes a sensor  33  for determining whether the chain  17  has been severed, as illustrated in  FIGS. 4 and 7 . In a preferred embodiment, this sensor  33  includes a magnetic field detector for determining whether a magnet is adjacent. For this embodiment, a magnet  35  is affixed to the chain  17  and positioned so as to be adjacent to the magnetic field detector  33  when the gate  3  is in a closed condition. Preferably, a second magnet  35  is affixed to the chain  17  toward the chain&#39;s opposite end for being adjacent to a second magnetic field detector  33  when the gate is in an open condition. 
     As illustrated in  FIG. 8 , the chain driven gate and security system  1  includes a processor  43  connected to the motor  25  and sensor  33 . Moreover, the processor is connected to an alarm  39  which may be any hardware or software construction for indicating that the chain  17  has been severed. The preferred alarm  39  includes a speaker for sounding an audible alert and one or more light sources for providing a visual indication indicating that the chain has been severed. Moreover, the chain driven gate and security system includes a power supply  47  connected to the motor  25  and processor  43 . The power supply  47  enables the motor  25  to be activated so as to rotate the sprocket  27 . In addition, the power supply  47  provides power to the processor  43  for computer processing. The processor may be a general purpose computer or microprocessor including hardware and software as can be determined by those skilled in the art to provide automated or directed control of the opening and closing of the gate as well as activation of the alarm. 
     In operation, the processor  43  controls the well-known functions of the gate including its opening and closing such as by depressing a button or receiving a radio frequency signal such as transmitted by a handheld remote. The processor  43  activates the motor  25  so as to propel the gate to open or close until a magnet  35  moves to be adjacent to a sensor  33  which occurs when the gate comes to an open or closed condition. Once this occurs, this sensor  33  transmits a signal to the processor  43  which deactivates the motor  25  so as to lock the gate  3  in an open or closed condition. 
     In the event that the gate is in a closed condition, the processor maintains an “alarm” condition until the processor has been triggered to open the gate. While in the “alarm” condition, the magnet  35  will be maintained adjacent to sensor  33  unless the chain  17  has been severed. In the event that the chain  17  is severed, the magnet  35  will drop away from the sensor as illustrated in  FIGS. 4 and 7 . The movement of the magnet  35  away from the sensor  33  causes a signal to be sent to the processor  43 . In the event that the processor indicates that the gate should be closed and the processor receives a signal from the sensor indicating that the magnet has dropped away from the sensor, the processor transmits a signal to the alarm  39  so as to provide a visual and/or audible indication that the gate&#39;s chain  17  has been severed. Preferably, the processor also prevents power from being transmitted to the motor  25  so as to maintain the motor in a deactivated condition. 
     While several particular forms of the invention have been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. Therefore, it is not intended that the invention be limited except by the following claims.