CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from U.S. Provisional Patent Application No. 60/293,200, filed May 25, 2001, entitled “ELECTRONIC OR MANUAL OPERATED FIREARMS SAFETY LOCKING SYSTEM,” the entirety of which is herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a firearm locking system and method, and more particularly, to a firearm locking system and method for preventing rotation of a cylinder. 
     2. Discussion of the Related Art 
     Throughout history, firearms have been used for protection and recreation. Many private citizens, fearing crime, have chosen to arm themselves in order to provide a feeling of security. Placing firearms in the home presents a number of potential problems, including the possibility of a child gaining access to the firearm or the possibility of an intruder gaining access to the firearm and using it against the homeowner. One option is to keep the firearm unloaded. However, an unloaded firearm will be ineffective against a surprise intruder. 
     A number of conventional solutions have been developed that permit the firearm to be loaded and ready for use, while preventing injury to children and use of the firearm by unauthorized users. For example, key locks have been developed which restrict operation of the gun triggers. These types of locks require a key for operation. Key locks, however, are often complex and cumbersome, presenting a significant obstacle to accessing the firearm quickly when necessary, such as to protect or defend against an intruder. Moreover, tampering with such locks may lead to accidental discharge of the firearm. 
     Firearm storage devices, such as gun cabinets, effectively secure firearms but do so at the expense of accessibility. These devices may also be quite expensive, requiring the consumer to choose between cost and safety. 
     More recent systems employ a magnetically actuable safety apparatus, which interacts with a magnet ring worn by the user, resulting in the enabling or disabling of the lock. Typically, such devices are extremely sensitive to ring positioning, leading to unreliable operation. In addition, the user must be in possession of the magnetic ring in order to disable the lock. 
     Thus, in view of the inadequacies of conventional firearm locking devices, there is a substantial need for an economical firearm locking system that can secure a firearm without sacrificing its availability for immediate use. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a firearm locking system and method for preventing rotation of a cylinder that solves the problems in conventional firearm locking systems as described above. 
     The invention provides a system and method for allowing a user to remotely disable and enable a firearm locking mechanism. Thus, a user of the locking system and method in accordance with the invention need not be in physical possession of the firearm in order to disable and enable the locking mechanism. This allows a user to quickly disable and use the firearm when needed. 
     Therefore, one aspect of the invention is to provide a locking system and method for a firearm that can be remotely disabled and enabled. 
     Another aspect of the invention is to provide a firearm locking system and method that includes a transmitter device for sending a locking enabling and disabling signal to a self contained locking system mounted on a firearm. 
     In accordance with these and other aspects, the invention provides a cylinder locking unit for a firearm adaptable to a firearm chamber, the cylinder locking unit including a receiver for generating a control signal upon receipt of a request signal; an electric actuator activated by the control signal received from the receiver; and a locking device extendible from the firearm chamber for preventing discharge of the firearm, the locking device extending upon activation of the electric actuator. 
     In a further embodiment, the invention provides a method for locking a cylinder-type firearm, which includes placing a cylinder locking unit in a firearm chamber; generating a control signal upon receipt of a request signal; activating an electric actuator upon receipt of a control signal; and extending a locking device from the firearm chamber to prevent discharge of a firearm, the locking device extending upon activation of the electric actuator. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are included to provide further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings: 
     FIG. 1 is a block diagram of a firearm locking system according to an embodiment of the invention; 
     FIG. 2 is a side view of a firearm showing the locked position of a firearm locking system according to an embodiment of the invention; 
     FIG. 3 is a side view of a firearm showing the unlocked position of a firearm locking system according to an embodiment of the invention; 
     FIGS. 4 a  and  4   b  are side views of a firearm locking mechanism according to an embodiment of the invention; and 
     FIG. 5 is a diagram illustrating a position shift from locked to unlocked position of a firearm locking system according to an embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
     FIG. 1 shows a block diagram of a firearm locking system in accordance with an embodiment of the invention. In particular, FIG. 1 shows an electronic transmitter  100  in communication with a cylinder locking unit  102 . The cylinder locking unit  102  includes a power source  110  coupled to an electric actuator  112  and a receiver unit  104 . The electric actuator  112  and receiver unit  104  are also coupled to each other. The receiver unit  104  includes a receiver  106  and antenna  108 . Each of these elements will be discussed in turn. 
     Turning to the electronic transmitter  100 , the electronic transmitter  100  may be permanent or portable. An example of a portable electronic transmitter includes a remote controller. The electronic transmitter  100  is capable of receiving input from a user. For example, the electronic transmitter  100  may include a depressible button  125  for sending a signal. In addition, the electronic transmitter  100  may include various security features, such as a thumb print identification system  130  or an iris/cornea pupil identifier system  135 , which only allow authorized users to operate the electronic transmitter  100 . The electronic transmitter  100  may be used to lock and unlock the firearm. The electronic transmitter  100  may be any one of standard off the shelf components capable of transmitting radio frequency transmissions. The electronic transmitter  100  sends a signal to the cylinder locking device  102  in order to operate the device  102 . 
     The cylinder locking unit  102  includes the receiver unit  104 , the power source  110 , and the electric actuator  112 . The electric actuator  112  includes a locking device. In accordance with an embodiment of the present invention, the cylinder locking unit  102  may be located in any one of the chambers of the cylinder of a firearm. In operation, a user initiates a request signal, which is transmitted from the electronic transmitter  100  to the receiver unit  104 . Specifically, the antenna  108  of the receiver unit  104  receives the request signal sent from the electronic transmitter  100 . The antenna  108  may be any one of standard off the shelf components capable of receiving radio frequency transmissions. The receiver  106  which receives the request signal may be a signal generator. The receiver  106  may be a small receiver such as a micro-receiver. In an embodiment of the invention, the receiver  106  includes an internal security component  120 . An example of the internal security component  120  includes the ability of the receiver  106  to self-destruct (e.g., by burning its circuits) upon disassembly. After receiving the request signal, the receiver  106  generates a control signal that is sent to the electric actuator  112 . 
     The electric actuator  112  may include a relay which completes the circuit when the control signal is received. Once the circuit is completed, current is delivered to the electric actuator  112 . 
     The power source  110  may be any AC or DC power supply, such as dry cell batteries providing DC current. The power source  110  provides power to both the receiver unit  106  and the electric actuator  112 . 
     The electric actuator  112  may be one of a variety of actuators, such as a solenoid or, alternatively, a motor. The electric actuator  112  may be configured to include a locking device. One type of locking mechanism in accordance with the invention is a plunger type device which is described in greater detail below. In accordance with one embodiment of the invention, the electric actuator  112  may be a solenoid held in position by at least one permanent magnet. The solenoid may be capable of moving the locking device (e.g. plunger) into a locked or unlocked position upon activation. For example, if the firearm locking system in accordance with the invention is in an unlocked position, activation of the electric actuator  112  will extend the locking device from the front of a cylinder chamber into the barrel (or forcing cone) of the firearm, thereby preventing rotation of the cylinder in either direction. Thus, the cylinder cannot be rotated or advance to bring a live cartridge into the firing position, and the firearm is locked. Alternatively, if the firearm locking system in accordance with the present invention is in a locked position, and the locking device is therefore extended into the barrel of the firearm, activation of the electric actuator  112  retracts the locking device out of the rear of the barrel (or forcing cone) and back into the front of the cylinder chamber, thereby permitting rotation of the cylinder. This unlocks the firearm and allows it to be operated. 
     The cylinder locking unit  102  may also be operated manually with the proper tool inserted from the muzzle end of the firearm, thereby overriding the electric actuator  112 . 
     FIGS. 2 and 3 illustrate side views of a firearm with the firearm locking system in the locked and unlocked positions, respectively, in accordance with an embodiment of the invention. Each will be discussed in turn. 
     FIG. 2 illustrates a side view of a revolver and, in particular, a revolver locked by the firearm locking system in accordance with an embodiment of the invention. It should be understood that the firearm locking system in accordance with the invention may be used on any hand or shoulder held firearms having a cylinder type mechanism. As shown in FIG. 2, the revolver includes a body  210  that includes a grip  220 , a trigger  230  and a barrel  240 . A cylinder  202  is mounted on the body  210 . The cylinder includes a plurality of chambers (not shown) capable of carrying ammunition. The cylinder locking unit  102  is in a chamber of the cylinder  202  of the firearm. The cylinder locking unit  102  includes a locking device  204 . 
     The locking device  204  is in the extended position, extending from the front of a cylinder chamber  206  into the rear of the barrel or forcing cone  208 . The extended locking device  204  may be a plunger-type structure that extends into the rear of the barrel or forcing cone  208 . In this extended position, the firearm locking system forms a positive lock, preventing the cylinder  202  from rotating in either direction and thus disabling the firearm. 
     FIG. 3 shows the firearm locking system in accordance with an embodiment of the invention where the locking device  204  is in an unlocked position allowing operation of the firearm. In FIG. 3, the cylinder locking unit  102  is positioned in the cylinder  202  and the locking device  204  is in a retracted position, in the front position of the cylinder chamber  206 . The retracted locking device  204  includes a plunger. In this retracted position, the locking device  204  does not extend into the rear of the barrel or forcing cone, thereby permitting rotation of the cylinder and the firearm is capable of firing. 
     FIG. 4 a  is a general view of the cylinder locking unit  102  in accordance with an embodiment of the invention. The cylinder locking unit  102  includes the electric actuator  112 . The electric actuator  112  includes a plunger  406  that is capable of extending into the rear of the barrel or forcing cone  208  of the firearm, thus preventing operation of the firearm. 
     In FIG. 4 a , the electric actuator has source connector openings disposed along its outer wall surface. A power source  420  abuts one end of the electric actuator. In accordance with the present invention, the power storage rack  402  may be connected to the electric actuator  112  by mating the power source connector pins  404 , preferably four pins, into power source connector openings  410  disposed on the outer wall surface of the actuator  112 . In an alternate embodiment, the power storage rack  402  may be connected to the electric actuator  112  by solder joints. The attachment of the power storage rack  402  to the electric actuator  112  forms a seal over the power source  420 . The antenna  108  is also mounted on the power storage rack  402 . The electric actuator  112  is connected to the plunger locking device  406 . 
     FIG. 4 b  shows a general view of the cylinder locking unit  102  in accordance with an embodiment of the invention. Like FIG. 4 a , FIG. 4 b  shows the actuator having a plunger  406 . FIG. 4 b  also shows receiver connector openings  440  disposed on the outer wall surface of the actuator  112 . A receiver  430  having receiver connecting pins  408  may be coupled to the actuator  112  by mating the receiver connector openings  440  with the receiver connecting pins  408 . In an alternate embodiment, the receiver  430  may be connected to the electric actuator  112  by solder joints. FIG. 4 b  also shows an antenna  108  mounted on the end of, and connected to, the electric actuator  112 . 
     Thus, in operation, a request signal is transmitted from the electronic transmitter  100  to the antenna  108 . The receiver  430  receives the transmitted signal and generates a control signal that completes a circuit engaging the electric actuator  112 . The electric actuator  112  then engages the plunger  406 , moving the plunger. 
     FIG. 5 shows a cross sectional view of the cylinder locking unit  102  in accordance with an embodiment of the invention. FIG. 5 shows the electric actuator  112  having the receiver  106 , power source  110 , and antenna  108  mounted upon its surface. The electric actuator  112  includes a plunger  406  capable of linear movement. In FIG. 5, the plunger  406  is in the first position  510  before the cylinder locking unit is engaged. Thus, in this position, the firearm is operable. When the cylinder locking unit  102  is engaged, the plunger  406  moves from the first position  510  to a second position  520 . Thus, the plunger  406  has moved linearly in a direction away from the body of the electric actuator  112 . Therefore, in position  520 , the plunger  406  extends to the rear of the barrel or forcing cone  208 , preventing operation of the firearm. 
     FIG. 5 shows the cylinder locking unit  102  in the unlocked position. Specifically, FIG. 5 illustrates the antenna  108 , receiver  106 , power source  110 , electric actuator  112 , housing for the cylinder locking unit (as shown in FIGS.  2  and  3 ), and plunger  406 . The plunger locking device  406  is in the retracted or unlocked position. In accordance with the present invention, the housing surrounds the antenna  108 , power source  110 , receiver  106 , and electric actuator  112 . An example of the housing includes a round cylinder which is sized in accordance with the caliber of the firearm. In an embodiment of the present invention, the housing may be made of a metal of composite material. The base of the housing may have a rim (as shown in FIGS. 2 and 3) with an opening for the antenna  108 . 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the firearm locking system of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that they come within the scope of any claims and their equivalents.
The invention describes a firearm locking system and method for preventing rotation of a cylinder. In particular, the firearm locking system and method of the present invention provides a cylinder locking unit for a firearm adaptable to a firearm chamber, the cylinder locking unit including a receiver, an electric actuator, and a locking device extendible from the firearm chamber for preventing discharge of the firearm, the locking device extending upon activation of the electric actuator.