Patent Publication Number: US-2021180363-A1

Title: Electronic locking apparatus and method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of application Ser. No. 13/835,838, filed Mar. 15, 2013. 
     All written material, figures, content and other disclosure in the above referenced application is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates generally to electronic locking mechanisms and in a more specific embodiment to a barrel lock with an electronic locking mechanism. 
     (2) Description of the Prior Art 
     Electrical service providers generally deliver electricity to their customers via power lines buried underground or distributed along poles or towers overhead. The provider&#39;s power lines are usually distributed from a power generation station to numerous sets of customer lines, so that customers can then use the power to satisfy their various electrical needs. To measure delivered power so that customers can be billed in proportion to their usage, service providers typically terminate their power lines at a customer&#39;s home or business facility through a metered socket box, various designs for which are well known. 
     Barrel locks have been used for many years to secure utility metering devices and service. Utilities have an ongoing requirement to secure their meters and service to prevent theft, vandalism and protect the public from coming into contact with dangerous voltages or situations. The barrel lock was originally developed to secure gas valves at a customer&#39;s point of service. U.S. Pat. No. 3,560,130 shows an example of a barrel lock used for such purpose. As electricity costs have risen, so has the need to secure electricity meters and other utility equipment. Locking hardware has been developed to secure other utility assets such as electricity meters and enclosures. Since utilities have many installations over a large service area there is a need to limit the variety of locks in the field since the proper key must be used for each type of lock in the field. Utilities have thus preferred to standardize on as few lock types as necessary. The since the barrel lock was one of the original types of locks in use in the field, there have been numerous devices developed that use the barrel lock to secure a wide variety of applications other than just gas valves. The barrel lock has had many improvements made that offer better security and reliability but have still maintained the basic external geometry to ensure compatibility with the large base of installed hardware. 
     U.S. Pat. No. 4,742,703, which is incorporated herein by reference, shows one such example of an improved barrel lock, having an improved locking mechanism yet still maintaining a compatible external geometry for broad compatibility with the hardware in use by utilities. U.S. Pat. No. 5,542,722, which is incorporated herein by reference, shows an example of a locking ring used with a barrel lock to secure an electricity meter. U.S. Pat. No. 5,870,911 shows an example of an enclosure lock for use with a barrel lock to secure an electricity meter enclosure. U.S. Pat. No. 5,960,653, which is incorporated herein by reference, shows an example of an adjustable closure lock for use with a barrel lock to secure the lid of a meter enclosure box. The forgoing examples are just a few examples of hardware developed to use a barrel lock. There are many other examples of hardware specifically designed to use barrel locks and are well known by those skilled in the art. 
     In existing mechanical locks and keys, the physical dimensions of various mechanical parts, the ability of the keys to open the locks is typically determined at the time of manufacture. Most such locks involve a plurality of tumblers, typically in the form of rotating discs, sliding rods, or tilting levers. The corresponding keys have related physical protuberances. When the key is presented to the lock, by pressing, inserting, rotating, and the like, the key pushes against the lock&#39;s tumblers and physically move them through angular or linear displacements. If the collection of such displacements matches the requirements of the lock, then the movement of the tumblers results in alignment of all tumblers in such a way that the lock is released to be unlocked. Such alignment may, for example, be the alignment of the ends of rod-like tumblers to a common plane or rotation of disc-like tumblers so that a hole or slot in each is aligned at a common angular position. 
     In the electric meter industry, control of keys utilized for unlocking barrel locks that secure the meter boxes and/or the meters within the meter boxes presents a number of problems. Access to the meter boxes provides access to electricity without the meter being able to register the amount of electricity being utilized. Keys can be lost or stolen or sold, requiring replacement or rekeying of the barrel lock and a temporary loss of control over the meter. If a key fits many locks, then it becomes expensive to rekey or replace the locks. 
     Mechanical locks are subject to being manipulated or “picked” by unauthorized users with the necessary tools and skills. The tools are typically inexpensive and the skills for manipulating locks are widely known and available to the public. 
     Because of the finite precision of mechanical devices and the necessity of tolerating manufacturing variation as well as dimensional changes from wear, mechanical locks can only be made with a limited number of codes, depending on the design, typically on the order of tens of thousands and almost never exceeding one million. If a system of locks requires more locks than this number, then it is inevitable that some keys will fit more than one lock. 
     In a system of locks and keys it can be desirable to assign the locks to groups. In present mechanical systems, it is more difficult to make a lock which can respond to more than a small number of different keys. Making a lock respond to more keys makes it easier for an unauthorized person to defeat the lock. The keys and locks in themselves do not provide any record of operation. Therefore, accountability for use of the keys is limited to records produced by the service technicians, which may be incomplete and do not account for many problems that can occur. 
     The prior art does not show the features of the present invention that provides greater control over keys and barrel locks without necessarily requiring replacement of barrel locks in the event keys are lost and greatly reduces the likelihood of loss of control of the meter when a key is lost or stolen. Accordingly, those of skill in the art will appreciate the present invention which addresses the above discussed problems. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved barrel lock. 
     Another possible object of the present invention is to provide a barrel lock with an electronically controlled actuator. 
     Accordingly, the present invention provides a barrel lock may comprise a body portion has a longitudinal axis. The body portion comprises a generally cylindrical head portion and a generally cylindrical shank portion. The shank portion has a smaller diameter than the head portion. 
     A movable retaining member is radially extensible and retractable relative to the longitudinal axis. 
     An electrically controlled actuator has an opened position and a locked position. The actuator maintains at least partial radial extension of the retaining member when in the locked position and allows radial retraction of the retaining member when in the opened position. 
     A control circuit is in electrical communication with the actuator, the control circuit capable of receiving a signal from a key and providing an electrical signal to the actuator when the proper signal is received by the control circuit from the key wherein the head portion comprises the control circuit. 
     The invention is used in combination with locking hardware and may comprise an aperture for receiving the shank portion and wherein the locking hardware is locked when the actuator is in the locked position. 
     The electrically controlled actuator can comprise a shape memory alloy, a solenoid, a piezoelectric actuator, a motor, a screw, a spur gear speed reducer, a planetary gear speed reducer. In one embodiment, the screw is driven by an electric motor in communication with the control circuit. 
     The head portion can define an axial direction and a radial direction. The head portion may comprise an interface for a key may comprise a recess formed generally in the radial direction of the key interface for gripping of the lock by a key. 
     In one embodiment, the electrically controlled actuator is changed between the locked position to the opened position by rotating relative to the retaining member. In another embodiment, the electrically controlled actuator is changed between the locked position to the opened position by moving linearly relative to the retaining member. The invention may further comprise a retaining member extender in the shank operable for moving the retaining member between the opened position and the closed position. The retaining members may or may not be biased by by a spring. 
     The content and disclosure of the following application/publication to the extent permitted is specifically hereby incorporated by reference: U.S. patent application Ser. No. 13/835,838, filed Mar. 15, 2013. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention. 
         FIG. 1  is a perspective view of an electronic key and corresponding electronic barrel lock in accord with one possible embodiment of the present invention. 
         FIG. 2  is a perspective view of an electronic key engaged with corresponding electronic barrel lock for operation in accord with one possible embodiment of the present invention. 
         FIG. 3 a    is an elevational view, partially in section, of an electronic key engaged with corresponding electronic barrel lock for operation in accord with one possible embodiment of the present invention. 
         FIG. 3 b    is an elevational view, partially in section, of an electronic key with contact pins engaged with corresponding electronic barrel lock contact pins for operation in accord with one possible embodiment of the present invention. 
         FIG. 4  is a perspective view of an electronic key for use with a corresponding authorizer in accord with one possible embodiment of the present invention. 
         FIG. 5  is a perspective view of an electronic key engaged for use with a corresponding authorizer in accord with one possible embodiment of the present invention. 
         FIG. 6  is a perspective view of an electronic barrel lock in accord with one possible embodiment of the present invention. 
         FIG. 7  is an elevational view, in cross-section, of a lock embodiment with a shape memory alloy (SMA) actuator in the locked configuration in accord with one possible embodiment of the present invention. 
         FIG. 8  is an elevational view, in cross-section, of a lock embodiment with a shape memory alloy (SMA) actuator in the unlocked configuration in accord with one possible embodiment of the present invention. 
         FIG. 9  is an exploded view of a lock embodiment with a shape memory alloy (SMA) actuator in the unlocked configuration in accord with one possible embodiment of the present invention. 
         FIG. 10  a perspective view of a control circuit is shown in accord with one possible embodiment of the present invention. 
         FIG. 11  is a perspective view of an electronic key in accord with one possible embodiment of the present invention. 
         FIG. 12  is an elevational view, in section, of an electronic key in accord with one possible embodiment of the present invention. 
         FIG. 13  is an exploded view of an electronic key in accord with one possible embodiment of the present invention. 
         FIG. 14 a    is one side of a circuit board for an electronic key in accord with one possible embodiment of the present invention. 
         FIG. 14 b    is an opposite side of a circuit board for an electronic key in accord with one possible embodiment of the present invention. 
         FIG. 15 a    is another embodiment of an electronic lock with a non-cylindrical body in accord with one possible embodiment of the present invention. 
         FIG. 15 a    is another embodiment of an electronic lock with a non-cylindrical body in accord with one possible embodiment of the present invention. 
         FIG. 16  is a perspective view with an enlarged portion showing stakes in a shank in accord with one possible embodiment of the present invention. 
         FIG. 17 a    is an elevational view, in section, showing an alternate embodiment of retaining members in accord with one possible embodiment of the present invention. 
         FIG. 17 b    is an elevational view, in section, showing another alternate embodiment of retaining members in accord with one possible embodiment of the present invention. 
         FIG. 18  is an elevational view, in cross-section, of a lock embodiment with an SMA actuator in the locked configuration in accord with one possible embodiment of the present invention. 
         FIG. 19  is a cross-section perspective of a lock embodiment with an SMA actuator in the un-locked configuration in accord with one possible embodiment of the present invention. 
         FIG. 20  is an exploded view perspective of a lock embodiment with an SMA actuator in accord with one possible embodiment of the present invention. 
         FIG. 21  is an elevational view, in cross-section, a lock with a solenoid actuator in the locked configuration in accord with one possible embodiment of the invention. 
         FIG. 22  is an elevational view, in cross-section, of a lock embodiment with a solenoid actuator in the un-locked configuration in accord with one possible embodiment of the invention. 
         FIG. 23  is an exploded view of a lock embodiment with a solenoid actuator in accord with one possible embodiment of the invention. 
         FIG. 24  is a cross-section perspective of a lock embodiment with a piezoelectric actuator in the locked configuration in accord with one possible embodiment of the invention. 
         FIG. 25  is a cross-section perspective of a lock embodiment with a piezoelectric actuator in the un-locked configuration in accord with one possible embodiment of the invention. 
         FIG. 26  is an exploded view perspective of a lock embodiment with a piezoelectric actuator in accord with one possible embodiment of the invention. 
         FIG. 27  is an perspective view of an embodiment of a barrel lock with a gear embodiment in accord with one possible embodiment of the invention. 
         FIG. 28  is an elevational view, in cross section, of a lock with gear drive in a locked position in accord with one possible embodiment of the invention. 
         FIG. 29  is an elevational view, in cross section, of a lock with gear drive in an unlocked position in accord with one possible embodiment of the invention. 
         FIG. 30  is an elevational view, in cross section, of a lock with gear drive illustrating an embodiment of a rotational limit sensor in accord with one possible embodiment of the invention. 
         FIG. 31  is an exploded view of a lock with a gear drive in accord with one possible embodiment of the invention. 
         FIG. 32  is an elevational view, in cross section, showing a barrel lock with screw drive in a locked position drive in accord with one possible embodiment of the invention. 
         FIG. 33  is an elevational view, in cross section, showing a barrel lock with screw drive in an unlocked position drive in accord with one possible embodiment of the invention. 
         FIG. 34  is an exploded view of an electronic barrel lock with screw drive in accord with one possible embodiment of the invention. 
         FIG. 35 a    is a flow chart for interaction of an electronic key with an electronic lock in accord with one possible embodiment of the present invention. 
         FIG. 35 b    is a flow chart for interaction of an electronic key with an authorizer and server in accord with one possible embodiment of the present invention. 
         FIG. 35 c    is a flow chart for interaction of an authorizer and server in accord with one possible embodiment of the present invention. 
         FIG. 35 d    is a flow chart for interaction of an electronic key with an authorizer and server in accord with one possible embodiment of the present invention. 
         FIG. 36 a    is a perspective view of a moveable bar interface of key and lock in accord with one possible embodiment of the invention. 
         FIG. 36 b    is a perspective view of a moveable bar interface of key and lock in accord with one possible embodiment of the invention. 
         FIG. 36 c     1  is an elevational view, in cross section, of a moveable bar interface of key and lock at start of engagement process in accord with one possible embodiment of the invention. 
         FIG. 36 c     2  is an elevational view, in cross section, of a moveable bar interface of key and lock at middle of engagement process in accord with one possible embodiment of the invention. 
         FIG. 36 c     3  is an elevational view, in cross section, of a moveable bar interface of key and lock at end of engagement process in accord with one possible embodiment of the invention. 
         FIG. 37 a    is an isometric view of the ball gripper key and end cap prior to engagement in accord with one possible embodiment of the invention. 
         FIG. 37 b    is an isometric view of the ball gripper key and end cap prior to engagement in accord with one possible embodiment of the invention. 
         FIG. 37 c    is an elevational view, with a break out section view, showing ball gripper key and end cap engagement in accord with one possible embodiment of the invention. 
         FIG. 38 a    is an isometric view of a male collet key and the end cap prior to engagement in accord with one possible embodiment of the invention. 
         FIG. 38 b    is an isometric view of a male collet key and the end cap prior to engagement in accord with one possible embodiment of the invention. 
         FIG. 38 c    is an elevational view, with a break out section view, showing a male collet key and end cap engagement in accord with one possible embodiment of the invention. 
         FIG. 39 a    is an isometric view of a female collet key and the end cap prior to engagement in accord with one possible embodiment of the invention. 
         FIG. 39 b    is an isometric view of the female collet key and the end cap prior to engagement in accord with one possible embodiment of the invention. 
         FIG. 39 c    is an elevational view, with a break out section view, showing a female collet key and end cap engagement in accord with one possible embodiment of the invention. 
         FIG. 40 a    is an isometric view of a friction gripping key and the end cap prior to engagement in accord with one possible embodiment of the invention. 
         FIG. 40 b    is an isometric view of a friction gripping key and the end cap prior to engagement in accord with one possible embodiment of the invention. 
         FIG. 40 c    is a break out section view of the friction gripping key and end cap engagement in accord with one possible embodiment of the invention. 
         FIG. 41  shows a schematic of a system communications system in accord with one possible embodiment of the invention. 
         FIG. 42  is a circuit diagram showing electronic key and lock interconnections with an electronic lock control circuit in accord with one possible embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner. 
     Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, the attached figures illustrate an apparatus for an electronic barrel lock, a key and an authorizer as well as a method of operation of the same.  FIG. 1  shows an example embodiment barrel lock  1  and a key  18 .  FIG. 2 ,  FIG. 3 a   , and  FIG. 3 b    show an example embodiment barrel lock  1  and key  18  engaged generally at  19  and being ready for opening. Item  111  represents an aperture in locking hardware, which physically mates to the lock in a manner that allows the hardware be locked. Locking hardware is discussed in more detail herein and various electrical box and flange locking hardware examples are given or referenced herein.  FIG. 4  shows an example embodiment key  18  and authorizer  23 . The key is engaged with the authorizing port  24  as shown in  FIG. 5 . Display  25  presents relevant information to the user during the authorization process. 
       FIG. 6  shows an example embodiment barrel lock generally at  1 . The barrel lock comprises a longitudinal axis  230 , a head portion  221  having a radial extent, in the current embodiment, defined by the outside diameter  4  of the head portion and a shank portion  220  having a radial extent, in one possible embodiment, defined by the outside diameter  6  of the shank portion. The radial extent  6  of the shank portion  220  is smaller than the radial extent  4  of the head portion  221 . The barrel lock also comprises movable retaining members  201 . The longitudinal axis  230  is defined by the axis that in this embodiment is the axis of a cylinder for head portion  221  and a corresponding cylinder for shank portion  221 . The retaining members  201 , which may be balls or other elements some of which are discussed herein, are radially extensible and retractable relative to the longitudinal axis  230 .  FIG. 7  shows a section view of the non-limiting example embodiment lock shown in  FIG. 6 , showing retaining members  201  in an extended position relative to the longitudinal axis  230 .  FIG. 8  shows a section view of the example embodiment lock shown in  FIG. 6  showing retaining members  201  in a retracted position relative to longitudinal axis  230 . The retaining members serve to retain the barrel lock in the locking hardware when the lock is locked. 
     Generally, when a barrel lock is unlocked the retaining members are retracted allowing the barrel lock to be removed from the locking hardware. Once the barrel lock is removed from the locking hardware, only then can access be gained to the particular device that it is protecting. This characteristic is one aspect which distinguishes barrel locks over mechanical cylinder locks such as the mechanical cylinder lock shown in U.S. Pat. No. 6,895,792. Mechanical cylinder locks are installed into the device which they protect and remain in place when opened as well as when they are locked. Furthermore mechanical cylinder locks do not have to be removed to allow access to the device which they protect. 
     The smaller radial extent of the shank portion of the barrel lock was originally designed to fit holes provided in gas valves installed in the field an example of which is shown in U.S. Pat. No. 3,560,130. The larger diameter head portion in some applications is used aid in further retaining the lock in some installations. In order to maintain compatibility with hardware in the field, it is imperative that the radial extents of the shank portion be maintained at a compatible radial extent with the hardware in use in the field which has been designed to accept barrel locks. A typical radial extent of the shank of an example barrel lock is 0.400 inches in diameter. Other barrel locks could of course have other radial extent dimensions as well as alternate cross-sectional shapes and still not depart from the scope of the present invention. In the present disclosure, the term “locking hardware” can be used to refer to any device which is secured by a barrel lock Accordingly, “locking hardware” can include meter box covers and rings that contain the meter in a meter box or other hardware, which is secured by barrel locks. 
     As discussed above, a barrel lock is commonly characterized as having a generally cylindrical case with a head portion, a smaller diameter shank portion, and a shoulder portion interposed between the head and shank portions. The shank portion includes retaining means, usually a pair of retractable steel balls, to prevent extraction of the lock from the meter ring or other locking hardware when the lock is locked. While a cylinder lock is retained in the locking hardware regardless of whether it is locked or unlocked, barrel locks must be removed from the locking hardware when they are unlocked. 
     Referring again to  FIG. 1, 6, 7, 9  a non-limiting example embodiment barrel lock is shown generally at  1 . The barrel lock comprises a longitudinal axis  230 , a head portion  221 , a shank portion  220 . The shank portion has retaining members  201 , in this embodiment each a ball. The retaining members are radially extensible and retractable relative to the longitudinal axis  230 . Referring to  FIG. 9 , electrically controlled actuator  10  comprises in one embodiment, shape memory alloy actuator. The electrically controlled actuator  10  can be of many variants of which several are presented here. This embodiment shape memory alloy actuator comprises a shape memory alloy wire  214 ′, circuit board  213 ′, fusible link  212 , actuator body  211 , spring  210  and retaining member driver  204 . 
     The actuator has an opened position as shown in  FIG. 8  and a locked position as shown in  FIG. 7 .  FIG. 7  shows the actuator in the locked position and maintaining radial extension of the retaining members  201 .  FIG. 8  shows the actuator in the opened position allowing radial retraction of retaining members  201 . The radial direction is generally perpendicular to the longitudinal axis  230 . When the retaining members are configured so that when they are extended radially, they project beyond the radial extents of the shank  220  and prevent the barrel lock from being removed from the hardware in which it is installed. 
     Referring to  FIGS. 6, 7, and 9  the actuator is located generally at the center of the head  221  and extends into the shank  220  to allow the retaining member driver  204  to contact retaining members  201 . The actuator is in electrical communication with the control circuit  207  through circuit board  213 ′ and fusible link  212 . The details and function of this example embodiment actuator will be explained later in this document. The control circuit  207  is capable of receiving a signal from key  18 , as shown in  FIG. 3 a   , and of providing an electrical signal to the actuator  10 , when the proper signal is received by the control circuit from the key through pins  20   a,    20   b,    20   c  and  20   d,  as shown in  FIG. 6 . The key contact pins are also shown in  FIG. 13 . The head portion  221  comprises the control circuit  207 . This configuration provides space for the physical extents of the control circuit and allows ready access to the key interface of the barrel lock shown generally at  21 . The key interface  21  of the present invention has a generally cylindrical boss  22  which is configured to be captured by the key as shown generally at  19  in  FIG. 3A . In some embodiments, it is advantageous for the key to capture the lock to aid in removal of the lock from the locking hardware when it is unlocked. 
     Referring now to  FIG. 6  and  FIG. 10  an example embodiment control circuit  207  is shown in isometric view. One possible embodiment for a control circuit of the present embodiment comprises circuit board  45 , diode  49 , microcontroller  47 , load switch  48 , capacitor  46  and contact pins  50   a,    50   b,    50   c  and  50   d.  The control circuit  207  in the present embodiment is mounted in the head portion  221  of the barrel lock  1  as shown in  FIG. 7 . The plane of the circuit board  45  is mounted in a generally perpendicular orientation to the longitudinal axis  230  close to the key interface  21 , discussed hereinafter. In further embodiments the control circuit could be mounted at the end of the head portion farthest from the key interface. In other embodiments the control circuit could be mounted in the head portion in an orientation generally parallel to the longitudinal axis. In still further embodiments the control circuit could be mounted in the head portion in an orientation having a generally oblique angle to the longitudinal axis. 
     Referring to  FIG. 6  and  FIGS. 9, 209   a ,  209   b ,  209   c , and  209   d  pass from the control circuit  207  to electrically connect power and signal lines to the key. In the present embodiment, four pins are shown for this purpose. In alternate embodiments two pins are used. In other embodiments three or more pins are used. Referring again to  FIG. 7  the control circuit  207  makes electrical contact with the electrically controlled actuator through fusible link  212 . Electrical contact in this embodiment is made between the control circuit  207  and fusible link  214  as discussed hereinafter. In other embodiments the control circuit  207  may be potted or coated with a protective coating as is well understood by those skilled in the art. Some of the functions provided by the potting or protective coating include protection from the weather, protection from tampering and protection from shock. 
     Referring now to  FIG. 42 , a block diagram of the circuit components of an exemplary embodiment key and lock is shown. This embodiment comprises four connections to the key, namely  52 ,  53 ,  54  and  55 . Connection  52  passes power from the actuator power system  56  in the key to be used to power the actuator  64 . The power for the actuator passes through diode  65  which serves to deter un-authorized opening by applying reverse biased power to pin  52 . Load switch  63  switches power supplied at pin  52  when switched by CPU  61 . CPU  61  receives power from the CPU power circuit  57  in the key. Power from the key passes through contact  53  and is de-coupled by decoupling capacitor  66  before arriving at CPU  61 . The CPU in the key  58  communicates through contact  54  with CPU  61  in the lock. Some examples of communications between the CPU in the lock and the CPU in the key include transfer of log data stored in memory  62  from the lock to the key and the unlock code sent from the key to the lock. Contact  55  provides a common or ground connection to complete the electrical circuits of the components described above. Thus, when the lock control circuit  67  receives the proper signal from key CPU  58  through contact  54  it provides an electrical signal through load switch  63  to actuator  64  to open the lock. Examples of the types of data stored in memory  62  include serial numbers of keys attempting to open the lock, the date of the attempts and whether the attempts were successful or not. 
     Referencing an embodiment shown in  FIGS. 3 a , 3 b   ,  7  and  9 , the end cap  205  performs multiple functions for the lock. First, it seals and protects the lock from weather and resists tampering as it is comprised of stainless or hardened tool steel making it difficult to drill or cut. Second, the end cap  205  is gripped by the key  18  to enable lock extraction from apertures of locking hardware. The key  18  engages with a radial groove in a male or female arrangement. Gripping may also be enabled with friction or magnetic attraction. Further details with exemplary embodiments are presented herein. Third, contact pins  209   a,    209   b,    209   c,    209   d  passes through end cap  205  and are insulated from electrical shorting to the conductive end cap  205  by lock contact pin insulator  206 . Lock contact pin insulator  206  is made of a plastic suitable for low voltage insulation and in this embodiment it  206  is polypropylene injection molded into the end cap  205 . The lock contact pins  209   a,    209   b,    209   c,    209   d  are made of conductive material such as brass that may be gold plated and pass through insulator  206  to externally present flush with face of end cap  205  at region of lock engagement  19 . 
     Referring to  FIGS. 6, 7 and 9 , the lock body  200  is comprised of shank portion  220  and head portion  221 . In this embodiment, the lock body  200  is cylindrical through which the longitudinal axis  230  passes through the cylinder center. Alternate embodiments as shown in  FIGS. 15 a  and 15 b    may be non-cylindrical, in which case the axis would be defined by the central axis of the smallest or best fit cylinder that can be fit around the outermost extents of the shank. 
     Referring to  FIGS. 6 and 16 , retaining members  201  extend from and retract into radial extent of lock shank portion  6  to respectively lock and unlock the barrel lock  1 . In the exemplary embodiment, the retaining members  201  are stainless steel ball bearings that pass through retaining member slots  224  and are retained within the shank portion  220  by retraining protuberances  223 . As shown in  FIGS. 17 a    and  17   b,  alternate embodiments can include a pin or lever to perform retaining member function to retain the barrel lock in the locking hardware when the lock is locked. The current and alternate embodiments of retaining member  206  are more fully described for manual locks in US Patent Publication 2012/0167369, which is incorporated herein by reference. 
       FIGS. 18, 19 and 20  depicts a non-limiting embodiment of a barrel lock with a shape memory alloy (SMA) actuator. From lock body  200 , retaining members  201  selectively radially extend beyond shank  220  or retract into shank  220  depending on whether the barrel lock is in the locked or unlocked position, respectfully. Retaining members  201 , in this non-limiting example balls, are biased to the locked position by bushing  202  that itself is biased by bushing extender  203  that bears against bushing  202  and insulating spacer  211 . Retaining member linear driver  204  is biased by SMA biasing member  210 , which may comprise a spring, in the extended and locked position as depicted in  FIG. 18  where retaining members  201  cannot recede toward longitudinal axis  230  of shank  220  because retaining member linear driver inhibition surface  217  prevents movement. One benefit of this design is that SMA biasing member  210  assists the actuator in returning to the locked position once power is removed. This ensures that the lock will return to the locked condition without relying on the key to re-lock it. This is desirable because there may be situations that arise where a user disengages the lock and key before properly locking the lock. 
     The barrel lock can be unlocked by driving an electric current through the shape memory alloy actuator  214 . In this non-limiting example, actuator  214  comprises a single 0.012 inch diameter nickel-titanium alloy wire, one possible example of which is described in U.S. Pat. No. 6,574,958. The SMA wire used in this embodiment is called Flexinol made by Dynalloy, Inc. for which technical characteristics are published online at www.dynally.com. The amount of electric current applied affects the response time of the actuator. In this embodiment, sufficient voltage of approximately 3.6 volts produces a current of approximately 2 amperes sustained for slightly less than one second. The current in response to internal resistance of the wire produces heat that causes the wire alloy to transition from martensite phase to austenite phase and, consequently, contract to shorten in length by typically 4.5%. If desired, this amount can be increased to about 7% with a reverse biasing member that stretches the wire in the martenite phase. SMA biasing member  210  provides the reverse biasing. In this non-limiting embodiment, the SMA biasing member  210  is a stainless steel compression spring assembled with approximately a two pound preload of continuous extension forces. The spring bears on insulating spacer  211  and retaining member linear driver  204 . 
     When the SMA actuator  214  contracts, it pulls both on the first and the second ends of a component stack inside the lock body shown in  FIG. 18-20  and also shown  FIG. 7 , another embodiment utilizing an SMA actuator, for which this description also applies as to general functionality. The first end of the SMA actuator  214  is attached to SMA actuator top crimp  215 , which is simply a stainless steel disk through which the SMA actuator  214  passes, which is crimped closed to grip. The SMA actuator top crimp  215  bears on conductive platform  213 , which may be composed of any conductive material. 
     In this particular embodiment, conductive platform  213  is a standard FR4 printed circuit board with conductive traces routing from surface mating with anti-tamper fusible alloy  212  to surface mating with SMA actuator top crimp  215 . The anti-tamper fusible alloy  212  bears on lock printed circuit board assembly  208 , which bears on insulating spacer  211 , which bears on lock body  200 . The insulating spacer  211  can be made of a molded or machined plastic. In this embodiment, insulating spacer  211  is an ultra-high-molecular-weight polyethylene. The second end of SMA actuator  214  passes through the central hole of the retaining member linear driver  204  and is attached at retaining member linear driver crimp end  222  by crimping. 
     This component stack is held in axial position within the lock body by the tight fit of the insulating spacer  211  within the head  221 . Thus, only the second end with the retaining member linear driver  204  is free to move when the SMA actuator  214  contracts. Contraction of SMA actuator  214  inside shank  220  causes retaining member linear driver inhibition surface  217  (See  FIGS. 18 and 19 ) to translate out of contact with retaining members  201  and brings the retaining member linear driver extraction ramp  218  into alignment with travel path of retaining members  201 . The narrow or small diameter profile of retaining member linear driver  24  exposed to retaining members  201  as shown in  FIG. 19  allows the balls to contract into shank  220 , resulting in placing the barrel lock in the unlocked position. 
     The user of the key will pull on the unlocked lock to remove the lock from the locking hardware. Any additional travel of the retaining member linear driver  204  along the longitudinal axis  230  necessary to allow retaining members  201  to radially travel toward the longitudinal axis  230  is accomplished by the retaining members  201  forcefully bearing upon retaining member linear driver extraction ramp  218  and, thereby, urge the retaining member linear driver  204  further along the longitudinal axis  230 . Force upon retaining member linear driver extraction ramp  218  results from user of key pulling the lock out of an aperture and the extraction force delivered by user is transferred from the resisting aperture to the retaining members  201  which bears upon retaining member linear driver extraction ramp  218 .  FIG. 18  shows lock embodiment in the un-locked configuration. 
     As stated above, the SMA actuator  214  responds to an electrical current. The current path flows from lock printed circuit board assembly  208  (See  FIG. 20 ), through the anti-tamper fusible alloy  212 , the conductive platform  213 , SMA actuator top crimp  215 , SMA actuator  214 , the retaining member linear driver  204 , to lock body  200 , which is grounded often naturally but also to the key. Elsewhere in this text is a description of how the lock control circuit  207  including lock printed circuit board assembly  208  and lock contact pins  209  behaves and are electrically energized. 
     Referencing  FIG. 9 , in this embodiment lock contact pin insulator  206  electrically isolates lock control circuit  207  from end cap  205 . Lock contact pin insulator  206  can be molded into end cap  205  to provide environmental protection and prevent shorting of SMA actuator  214  to end cap  206 . 
     Anti-tamper fusible alloy  212  is a metal alloy that transitions from solid to liquid over a narrow and specific temperature. Because the SMA actuator  214  actuates in response to heat, one obvious means of tampering and defeating the lock is to apply heat. The fusible alloy selected transitions to liquid at a temperature just below actuation temperature, 90° C. The current embodiment uses an alloy containing Indium, Lead and Tin. There is extensive public information on fusible alloy and common compositions for specific melt temperatures. When the anti-tamper fusible alloy  212  melts, this eliminates support at the first end of the SMA actuator  214  where it is attached to SMA actuator top crimp  215 . Accordingly, when SMA actuator  214  contracts after anti-tamper fusible alloy  212  melts, the retaining member linear driver  204  does not move. Consequently, the lock becomes inoperable but remains in the lock configuration due to the bias of SMA biasing member  210 . Conductive platform  213  conducts heat applied during tampering. By minimizing thermal conductivity, the effectiveness of fusible alloy protection is improved. 
     An alternate embodiment of the SMA lock where the SMA actuator  214 ′ and conductive platform  213 ′ are different is presented in  FIGS. 7, 8, and 9 . In this embodiment, SMA actuator  214 ′ wire is a loop that straddles conductive platform  213 ′ and, consequently, obviates the SMA actuator top crimp  215 . Both ends of the end of the SMA actuator  214 ′ passes through the central hole of the retaining member linear driver  204  and are attached at retaining member linear driver crimp end  222  by crimping. This loop configuration enables use of a smaller diameter wire of 0.010″ diameter, which has a higher resistance of 0.5 Ohms per inch versus 0.33 for the single wire with a diameter of 0.012″ A higher resistance requires a lower amperes of current to attain transition temperature, which benefits the circuit and key battery. However, the straight wire solution depicted in  FIG. 18-20  is typically easier to assemble. Additional alternate embodiments could include multiple loops or multiple single strands of SMA actuator wire. 
       FIGS. 21, 22 and 23  depict an embodiment of a barrel lock with a solenoid actuator. From the lock body  300 , retaining members  301  selectably radially extend beyond shank  320  or retract into shank  320  depending on whether the lock is in the locked or unlocked position. In the locked position, as shown in  FIG. 21 , the larger diameter portion of retaining member linear driver  304  impedes radially inwardly movement of retaining members  301 . To unlock this embodiment, the retaining member linear driver  304  is pulled by user along longitudinal axis  330  until retaining members  301  are no longer inhibited from retracting radially toward longitudinal axis  330  until fully recessed inside shank as shown in  FIG. 22 . The retaining member linear driver  304  translates along the longitudinal axis  330  until retaining member linear driver biasing member  310  is at full travel. In this embodiment, retaining member linear driver biasing member  310  is a stainless steel compression spring that can travel about 30% of overall length. When the retaining member linear driver  304  is released, retaining member linear driver biasing member  310  forcefully returns to the locked position as shown in  FIG. 21 . 
     Before the lock can be manually unlocked by manually pulling the retaining member linear driver  304 , intermediary retaining member  315  must exit from retaining member linear driver intermediate retainer  317 . Intermediary retaining member  315  can translate along intermediate track  312  within structural member  311  and is further restricted by retaining member linear driver  304  and solenoid plunger  316 . Solenoid  314  is held in position within structural member  311  inside head  321  by solenoid retainer  313 , which is simply an appropriately sized and positioned cavity. Structural member  311  can be made of steel, aluminum, plastic or other inert structural material. In this embodiment it is made of ferritic stainless steel for corrosion protection and resists tampering efforts with use of magnets outside of lock body  300 . Solenoid  314  is integrated into the lock control circuit  307  by wire or soldered directly to lock printed circuit board assembly  308 . The lock control circuit  307  is energized by and communicates with a key described elsewhere via lock contact pins  309  that are electrically isolated from lock body  300  and end cap  305  by lock contact pin insulator  306 , which may be molded into end cap  305  or be either molded or machined sleeves. 
     When solenoid  314  is energized by lock control circuit  307 , solenoid plunger  316  retracts into solenoid  314  and allows movement of the retaining member linear driver  304 . In the locked configuration, the solenoid  314  is not energized by lock control circuit  307 , causing solenoid plunger  316  to extend from solenoid  314  into track  312  which pushes intermediary retaining member into retaining member linear driver intermediate retainer  317  and, thus, inhibits movement of the retaining member linear driver  304 . 
       FIGS. 24, 25 and 26  depicts a non-limiting embodiment of a barrel lock with a piezoelectric actuator. From the lock body  400 , retaining members  401  selectably radially extend beyond shank  420  or retract into shank  420  depending on whether the lock is in the locked position ( FIG. 24 ) or unlocked position ( FIG. 25 ). In the locked position retaining member linear driver inhibition surface  417  impedes radial movement of retaining members  401 . To unlock this embodiment, the retaining member linear driver  404  attached to piezoelectric threaded shaft  415  is translated about 0.075 inches toward end cap  405  by a piezoelectric linear actuator  414  until retaining members  401  are no longer inhibited from retracting radially toward longitudinal axis  430  until fully recessed inside dy shank  420  as shown in  FIG. 25 . Various types of piezoelectric actuator designs that produce linear positioning are available that may be utilized in the barrel lock shown herein. Additionally piezoelectric actuators are available that provide rotational positioning that could be incorporated to provide locking and unlocking actuation with use of a retaining member rotary driver described elsewhere herein. 
     In this non-limiting embodiment, to unlock the electronic barrel lock, piezoelectric linear actuator  414  must translate the retaining member linear driver  404  into the unlocked position of  FIG. 25 . To relock the electronic barrel lock, piezoelectric linear actuator  414  must reposition the retaining member linear driver  404  into the locked position of  FIG. 24  without the assistance of a biasing mechanism to automatically relock the lock. Accordingly, logic in the electronic key can preferably be implemented to prevent leaving the retaining member linear driver  404  in the unlocked position. The retaining member linear driver reposition ramp  418  assists the piezoelectric linear actuator  414  to smoothly push retaining members  401  radially outward from longitudinal axis  430  while relocking. A user may inappropriately place the lock in a situation that impedes radial movement of retaining members  401 , such as improperly positioning the lock in the locking hardware, in which case the locking procedure would fault. In this case, the key can be programmed to record the fault event and recover by again trying to place the lock in the locked position. 
     The piezoelectric linear actuator  414  is attached electrically by means of a flat flex harness and physically by means of actuator enclosure riveted to lock printed circuit board assembly  408  that is held in longitudinal position by structural spacer  411  inside head  421  that surrounds and centers assembly about longitudinal axis  430 . The lock control circuit on circuit board  408  is energized by and communicates with a key described elsewhere via lock contact pins  409  that are electrically isolated from lock body  400  and end cap  405  by lock contact pin insulator  406 , which in this embodiment is molded into end cap  405 . Structural member  411  can be made of steel, aluminum, plastic or other inert structural material. Geometry of structural member  411  may also be merged with geometry of lock body  400 , if desired, to thereby eliminate the structural member  411  component. 
     This embodiment includes components bushing  402  and bushing extender  403  that in cooperation with retaining member linear driver insertion ramp  416  and retaining member linear driver inhibition surface  417  enables keyless insertion of lock into aperture. Keyless insertion technology is described more thoroughly elsewhere in text. 
     As shown in the  FIG. 31 , yet another non-limiting embodiment of an electronic barrel lock according to the present invention comprises of body  500 , retaining members  501 , bushing  502 , bushing extender  503 , retaining member rotary driver  504 , end cap  505 , lock contact pin insulators  506 , lock control circuit  507 , lock printed circuit board assembly  508 , lock contact pins  509 , actuator sub assembly enclosing plate  510 , lock position transmitting plate  511 , gear drive  512 , lock position transmitting pin  513 , actuator housing  514  and motor  515 . 
     In this embodiment, the actuator comprises motor  515 , which drives retaining member rotary driver  504  through a gear drive  512 . As an alternative embodiment the motor  515  can be connected directly to retaining member rotary driver to form a direct drive. 
     The retaining member rotary driver  504  moves rotationally with respect to the longitudinal axis  550  to drive the retaining members  501  into either locked or unlocked position. In the locked position, flat  516  on retaining member rotary driver  504  is normal to the retaining members  501  as shown in  FIG. 28 . In the unlocked position, flat  516  on the retaining member rotary driver  504  is tangential to the retaining member  501  as shown in the  FIG. 29 . 
     In this embodiment, retaining member rotary driver  504  is driven by the motor  515  indirectly through a spur gear box. As an alternate embodiment, the retaining member rotary driver  504  can be driven by the motor  515  using a planetary gear box. 
     The position of the retaining member rotary driver  504  is controlled by a feedback provided by the rotation limit sensor which indicates whether the lock is in either locked or unlocked position. This ensures that the lock is either fully locked or fully open as shown in  FIG. 28  and  FIG. 29  respectively. In one embodiment, the rotation limit sensor comprises of the lock position transmitting plate  511  and lock position transmitting pin  513  working in collaboration with the control circuit. The lock position transmitting plate  511  has crests  517  and troughs  518  as shown in  FIG. 31 , which can be configured to correspond to either locked or unlocked position of the retaining member rotary driver. The lock position transmitting plate  511  is coupled to the retaining member rotary driver  504  to turn together. The lock position transmitting pin  513  rides on the surface of the lock position transmitting plate  511  and transmits the position of the retaining member rotary driver  504  when it passes thru a trough  518  or crest  517 . The lock position transmitting pin  513  can transmit the signal to the control circuit by making an electrical contact with the circuit board or by sensing the capacitance change between the pin and the circuit board as shown in  FIG. 30 . 
     Alternatively, inductive sensing with circuit board or opto-electric sensing can be used to achieve the same. Similar arrangement can be used for retaining member linear driver. 
     As shown in the  FIG. 34 , another non-limiting embodiment of the present invention comprises body  600 , retaining members  601 , bushing  602 , bushing extender  603 , retaining member linear driver  604 , end cap  605 , lock control circuit  607 , lock printed circuit board assembly  608 , radially insulated lock contact pins  609 , O-ring  610 , motor  611 , driver screw  612 , driven member  613 , and alignment member  615 . 
     In the current embodiment the retaining member linear driver  604  moves axially along the longitudinal axis  650  to drive the retaining members  601  into either locked or unlocked position as shown in  FIG. 32  and  FIG. 33  respectively. 
     The movement of the retaining member linear driver  604  along the longitudinal axis  650  is achieved thru the driven member  613  which is driven by the driver screw  612  which in turn is driven by the motor  616 . The driver screw  612  attached to the motor is stationary along the axis parallel to the longitudinal axis  650 . The radial movement in the driver screw  612  causes the driven member  613  to either move up or down due to its engagement with the threads on the driver screw  612 . 
     The retaining member linear driver  616  movement along the longitudinal axis  650  is constrained to ensure the lock is fully locked or unlocked. In the current embodiment, the locked position is shown in  FIG. 32  where the retaining member linear driver  616  is constrained by the locking stop  619  which makes contact with the alignment member  615  to ensure the locked position where retaining members  601  are engaged with the locking surface  618  of the retaining member linear driver  616 . Similarly, the unlocked position is shown in  FIG. 33  where the retaining member linear driver  616  is constrained by the unlocking stop  620  which makes contact with the bottom surface  621  of the body  600  to ensure an unlocked position where the retaining members  601  are adjacent to the recessed surface  617  of the retaining member linear driver  616 . 
     In the current embodiment it can be seen that the driven member  613  has a uniform groove  622  along its diameter instead of a thread to prevent unintentional rotational motion retaining member linear driver  604  instead of desired linear motion along the longitudinal axis  650 . 
     In an alternate embodiment, the driven member feature can be incorporated as an internal thread or external in the retaining member linear driver  604  to interact with the driver screw  612 . 
     Referring to  FIG. 11  showing an example embodiment key  18 . The key has a key body portion  27  and a lock engaging portion  26 .  FIG. 12  shows a cross-sectional view of an example embodiment key  18 . The key body portion  27  has a lower body portion  28  and an upper body portion  29  which are held together by screws  31   a  and  31   b  as shown in  FIG. 5 . When assembled the upper body portion and lower body portion contain key control circuit  30 , power supply  33   a  and  33   b  which in the current embodiment are two batteries connected in series. Batteries  33   a  and  33   b  are in electrical contact with key control circuit  30  and provide power through standard battery contacts. This power is for the key control circuit operation as well as power that is supplied to the barrel lock when it is operated. While the exemplary embodiments presented herein of lock is powered by the key with no battery in the lock, alternate embodiments may include a battery, and/or power from the locking hardware such as the utility box. 
     Referring to  FIGS. 12 and 13 , the lock engaging portion  26  comprises collar portion  32 , which is mounted on tubular portion  37  and is free to slide. Spring  39  bears against the collar portion and forces it into contact with pin  40  which retains the collar portion on tubular portion  37 . Additional aspects of the function of these elements will be described below. Retaining pin  38  is inserted into hole  41  in lower body portion  27  and interacts with groove  42  in tubular portion  37  to retain it. Insulator  36  is positioned coaxially inside tubular portion  37  and supports electrical contact pins  20   a,    20   b,    20   c,  and  20   d  and insulates them from each other. The electrical contact pins  20   a,    20   b,    20   c,  and  20   d  make contact with pins  35  on key control circuit  30  and transmit signals and power from the key control circuit to the lock. 
     Referring to  FIGS. 13,19, 36   a ,  36   b ,  36   c   1 ,  36   c   2 , and  36   c   3 , moveable pin key  880  grips lock end cap  882  by inserting moveable pin  886  into end cap groove  883 . The lock has a radial direction generally perpendicular to its longitudinal axis and comprises an interface for the key comprising a recess (in this embodiment, a groove  883 ) formed generally in the radial direction for gripping of the lock by the key. In the present embodiment the recess is formed inward toward the longitudinal axis. In other embodiments the groove is formed outward, away from the longitudinal axis, such as the groove  834  shown in  FIG. 38 b   . Still further embodiments may have groves formed at a generally oblique angle relative to the longitudinal axis. In still further embodiments the groove is continuous while in even further embodiments the groove is discontinuous. Moveable pin  886  is urged into and held in position by pin driver ramp  887  that translates along axis and presses against end one and two of moveable pin  886 . 
     The process of inserting and gripping the lock end cap  882  begins as shown in  FIG. 36 c     1  with cylindrical protrusion  884  entering into the key tubular alignment recess  889  which defines axis  881  to accomplish alignment along axis  881 . By lightly forcing the key further on the end cap  882 , the first and second ends of the moveable pin  886  bears on the pin driver ramp  887  causing the key collar  891  to retract away from the end cap as the moveable pins translate within the tracking slot  888 . The user rotates the key about the axis  881  to find alignment of lock alignment ramp  893  with moveable pin  886  which can be felt by providing light pressure of key against lock and when alignment is found key slides toward end cap  882  as shown in  FIG. 36 c     2  and stops when end cap stop surface  894  and key stop surface  895  come into contact as shown in  FIG. 36 c     3  and the tracking slot  888  and end cap groove  883  are then positioned so that the moveable pin  886  can enter the end cap groove  883 . The collar which is urged forward by a biasing spring  39  cams the moveable pin  886  ends one and two against pin driver ramp  887  and thus pushing the moveable pin  886  into the end cap groove  883 . Key contact pins  892  and lock contact pins  885  are in positional alignment and compressive contact to ensure good performance. The key has a firm grip on lock for pulling lock out of locking hardware. To disengage, the user simply pulls the collar  891  away from lock end cap  882  and as it translates along the axis  881 , the moveable pin is freed to move in tracking slot  888  to disengage and release lock. 
     As shown in  FIG. 37 a    and  FIG. 37 b   , one possible embodiment includes a ball gripper key  800  and an end cap  810 . In the current embodiment the ball gripper key  800  utilizes ball grippers  803  to interact with a groove  811  in the end cap  810 . 
     The ball gripper key  800  includes an outer driver sleeve  801 , inner sleeve  802 , ball grippers  803  and alignment pins  806 . The ball grippers  803  move radially with respect to the axis  809 . The outer driver sleeve  801  and the inner sleeve  802  move relative to each other along the axis  809 . 
     The position of the ball grippers  803  in the inner sleeve  802  is controlled by the drive surface  805  ( FIG. 37 c   ) and undercut  804  in the outer driver sleeve  801 . When the outer driver sleeve disengage surface  807  and the inner sleeve disengage surface  808  are coplanar the ball grippers shift into the outer driver sleeve undercut  804  in the outer driver sleeve  801  and let the key mate with the end cap  810 . Upon retraction of the outer driver sleeve  801  along the axis  809  as shown in the  FIG. 37 c   , the outer driver sleeve drive surface  805  shifts the ball grippers to interface with the groove  811  in the end cap  810  to grip it. The alignments pins  806  in the outer driver sleeve  801  mate with the alignment surface  812  in the end cap  810  to maintain any necessary orientation. In an alternate embodiment the key can be designed to mate with an internal groove in the end cap. 
     As shown in  FIG. 38 a    and  FIG. 38 b   , an embodiment can include a male collet key  830  and an end cap  833 . This key embodiment utilizes collets to grip the end cap  833 . Male collet key  830  includes a driving member  831  and a collet member  832 . The collet fingers  835  move radially with respect to the axis  837 . The driving member  831  and the collet member  832  move relative to each other along the axis  837 . 
     As shown in  FIG. 38 a    and  FIG. 38 b   , in the disengaged position the driving member  831  is recessed back in the collet member  832 . This accommodates the radial displacement of the collet fingers  835 . The radial displacement of the collet fingers  835  enables the engagement of the collet engagement surface  836  with the end cap groove  834 . As shown in the  FIG. 38 c   , the driving member  831  moves into the collet member  832  restricting the movement of the collet fingers  835  radially to prevent the disengagement with the end cap  833  and thus grip it. 
     As shown in  FIG. 39 a    and  FIG. 39 b   , yet another embodiment includes a female collet key  850  and an end cap  855 . This key embodiment utilizes collets to grip the end cap  855 . Female collet key  850  includes a constraining member  851  and a collet member  852 . The collet fingers  853  move radially with respect to the axis  858 . The constraining member  851  and the collet member  852  move relative to each other along the axis  858 . 
     As shown in  FIG. 39 a    and  FIG. 39 b   , in the disengaged position the constraining member  851  is recessed back around the collet member  852 . This accommodates the radial displacement of the collet fingers  853 . The radial displacement of the collet fingers  853  enables the engagement of the collet engagement surface  859  with the groove  856  of the end cap  855 . As shown in the  FIG. 39 c   , the constraining member  831  envelopes the collet member  852  in engaged position restricting the movement of the collet fingers  853  radially to prevent the disengagement with the end cap  855  and thus grip it. The alignments pins  854  in the collet member mate with the alignment surface  857  in the end cap  855  to maintain any necessary orientation. 
     As shown in  FIG. 40 a    and  FIG. 40 b   , the current embodiment includes a friction gripping key  870  and an end cap  874 . The current key embodiment utilizes friction to grip the end cap  874 . 
     The friction gripping key  870  includes a driver  871  and a gripper  872 . The driver  871  and the gripper  872  move relative to each other along the axis  876 . The gripping fingers  877  move radially with respect to the axis  876  which enables the opportunity of gripping the end cap  874  using friction. 
     As shown in  FIG. 40 a    and  FIG. 40 b   , in the disengaged position the driver  871  is recessed back around the gripper  872 . As shown in  FIG. 40 c   , in the engaged position the driver  871  moves relative to the gripper  872  and rides over the gripper taper  873  causing the gripping fingers  877  to move radially inward to make a frictional contact with the end cap gripping surface  875  and thus grip the end cap  874 . 
     In an alternate embodiment, magnetic force can be used to grip the end cap. The gripper component of the key can be a magnetic material such as rare earth magnet and the end cap can be made out of a ferrous material such as low carbon steel. Since low carbon steel is attracted to magnetic field it aids in the gripping of the end cap. 
     All the above key gripping component embodiments are generally made out of tough materials such as stainless steel or tool steel unless stated otherwise. 
       FIG. 41  shows a block diagram of an example embodiment of the communication between a lock  937 , key  938 , authorizer  939  and server  940 . All devices communicate bi-directionally using a request/response message binary protocol. Messages have a header and body. The header allows for validation of the message integrity and requesting retransmission of a message. The body contains a payload that varies depending on the purpose of the request or response. 
     Referring to  FIG. 4 , the example embodiment authorizer  23  is a means of communicating with an example embodiment key  18 , a user interface  25  and a means of communicating with a server such as an Ethernet port. 
     Authorizer port  24  is constructed to mate with key  18  in the same manner at it mates with lock  1  as described in detail herein. Contact pins of key  20   a,    20   b,    20   c  and  20   d  (see  FIG. 13 ) align and contact with authorizer contact pins  34   a,    34   b,    34   c  and  34   d  in authorizer port  24  to enable communication with server  940 . 
     Referring to  FIG. 41  example authorizer  939  and server  940  communicate over the Internet using the HTTP/1.1 protocol as specified by RFC 2616. The body of the HTTP message contains encrypted messages conforming to the binary communication protocol. 
     The authorizer  939  comprises the functions: gathering user identification data through a human interface  25 , transmitting identifying data, encapsulating and relaying of data from the key  18  to the server  940 , and presenting feedback from the server to the user through a human interface  25 . 
     Referring now to  FIG. 35 c   , the authorizer and Server communication is as follows. A user connects a key  18  to an authorizer  23  as shown in  FIG. 5  and the authorizer establishes communication with the key. This step is illustrated in  FIG. 35 c    at  923 . Then the Authorizer gathers user identification information  924  from user via a human interface. The authorizer initiates communication to the server  925  by sending its authentication information  926 . If the server rejects the authorizer, it notifies the authorizer and ends communication  933 . Otherwise, the server sends its authentication information to the authorizer. If the authorizer rejects the server, it ends communication  934 . Otherwise, the authorizer transmits the user identification information to server  929 . If the server rejects the user, it notifies the authorizer  935  and ends communication  936 . Otherwise, the server notifies the authorizer of acceptance. Then the authorizer encapsulates and relays data between the server and key  931  until it received a message from the server to end communication  932 . Then it ends communication  936 . 
     Referring to  FIG. 35 a    showing a schematic of an example embodiment key and lock communication sequence. The key and lock communication involves the functions: mutual authentication of the lock and key  904  and  905 , transmitting identifying data  903 , verifying the key&#39;s authority to operate a lock  907 , transmitting logging data  908  gathered by the lock to the key, and transmitting operating commands from the key to the lock  906 . 
     The key and lock communication is as follows. The key powers up the lock  901 . The lock initiates communication by sending its authentication information  902 . If the key rejects the lock  904 , it ends communication  911 . Otherwise, the key sends its authentication information to the lock  903  and the lock records information about the key and the time and date of the communication. If the lock rejects the key  904 , it ends communication  911 . Otherwise, the lock communicates confirmation to the key and the key transmits the unlock code to the lock  906 . Next, the lock determines if the key has the authority to operate it  907 . If it does not have authority, the lock ends communication  911 . If the key has authority, the key requests logging data from the lock and the lock sends logging data to the key  908 . The key stores the logging data  909  and sends the unlock code to the lock. If the lock rejects the unlock code, it notifies the key and ends communication. Otherwise, the lock activates and opens. When the lock&#39;s activation is complete, it notifies the key and ends communication. 
     Referring to  FIG. 35 b    showing a schematic of an example embodiment key and authorizer communication sequence. The key and authorizer communication involves the functions: mutual authentication of the key and authorizer, transmitting identifying data, and relaying data between the key and the server via the authorizer. 
     Referring to  FIG. 35 d   , the key and authorizer communication is as follows. A user connects a key B 18  to an authorizer B 23  as shown in  FIG. 5  and the authorizer establishes communication with the key  941 . The authorizer initiates communication by sending its authentication information  942 . If the key rejects the authorizer, it ends communication. Otherwise, the key sends its authentication information  944 . If the authorizer rejects the key, it ends communication. Otherwise, the authorizer communications acceptance to the key. Then the authorizer relays data between the server and key  946 . After the key ends communication with the server, it ends communication with the authorizer  947  and  948 . 
     Referring to  FIG. 35 c    showing a schematic of an example embodiment key and server. The key and server communication involves the functions: mutual authentication of the key and server, transmitting identifying data, transmitting logging data from key to the server, and transmitting of authorization data from the server to the key. 
     Pertaining to the authorization data transmitted from the server to the key, the communication comprises of data required by the key to verify the key&#39;s authority to operate a lock, and limits to the key&#39;s usage. Limits to the key&#39;s usage include time of day, total operations, and time in service. 
     Referring now to  FIG. 35 c   , the key and server communication is as follows. The key and server communicate via the authorizer  912 . The server initiates communication by sending its authentication information  913 . If the server rejects the key, it ends communication  914 . If the key rejects the server, it ends communication  915 . If the server rejects the user&#39;s authority to use the key, it ends communication  916 . Otherwise, the server requests logging data from the key  917 . The key transmits logging data to the server  918 . The server stores the data, then sends the authorization data to the key  919 . The key indicates success. Then the server closes communication  920 . 
     Referring to  FIG. 41 , the server  940  is a central database that contains data pertaining to all locks, keys, and authorizers, a means of communicating with an authorizer  939 , and a means of communicating with a key  938  via the authorizer  939 . 
     In one example embodiment, the server communicates with the authorizer over the Internet. The server maybe a remote server, a local server, or any other device that is capable of communicating with the authorizer. Other example embodiments use infra-red communication between the authorizer and server while still other embodiments use a radio frequency communication link between the two devices. The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description only. It is not intended to be exhaustive nor to limit the invention to the precise form disclosed; and obviously many modifications and variations are possible in light of the above teaching. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.