Patent Publication Number: US-8528373-B2

Title: Electronic cam assembly

Description:
CLAIM FOR PRIORITY 
     This application is a divisional application of parent application Ser. No. 09/092,080, and a continuation of Ser. No. 09/463,420, that makes reference to, incorporates the same herein, and claims all right accruing from our earlier filing of a provisional patent application entitled Electronic Cam Assembly filed in the United States Patent &amp; Trademark Office on the 6 Jun. 1997 and there assigned Ser. No. 60/050,941, and our patent application entitled ELECTRONIC CAM ASSEMBLY filed in the United States patent &amp; Trademark Office on the 5 Jun. 1998 and there assigned Ser. No. 09/092,080, and issued on the 3 Apr. 2001 as U.S. Pat. No. 6,209,367. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to access control, and, more particularly, to manually operated, electronically keyed locks and locking processes suitable for retrofitting existing appliances. 
     2. Description of the Related Art 
     Current designs for maintaining security of containers such as bank safe deposit boxes require attended access and, all too frequently, dual keys, to allow access to the various containers maintained. We have found that the use of dual keys has become increasingly expensive in terms of man hours consumed by the employees of the bank providing attendance to the customers of the bank. Historically, safe deposit locks as well as other locks, have used a keyed cylinder that is offset from the centerline of the casing for the lock, within the body immediately behind the front plate of the safe deposit door. It was the object of this design to accommodate a full sized set of mechanical tumblers within the casing immediately behind the front plate of the door. The economics of safe deposit box rental require that the casing of the lock be made narrow in order to provide a high degree of security for the door while minimizing the loss of volume of the door due to the presence of the casing for the lock. The offsetting of the centerline of the keyway in turn allows the use of a more conventional and secure design within the very narrow compartment doors, as well as within taller doors. By the expedient of placing the cylinder of the lock in the lower portion of the casing, below the centerline of the casing and vault, the key could lift a set of larger tumblers without requiring an undesirably larger lock casing. The economy of providing uniform lock design, over the years, for differing applications has resulted in an existing installed base of millions of these locks. While not all of these locks rely upon offset keyed cylinders (referred to as “noses” in the trade), many do. 
     Four major lock manufacturers currently continue to produce locks with offset keyed cylinders, while at least two other manufacturer that have discontinued production, continue to have a large installed base. One of the most popular offset locks in the current market is the 4440 series left hand and right hand model manufactured by Sargent and Greenleaf. We have noticed a need to retrofit existing offset keyed cylinder locks with electro-mechanical locks, without expensive and inconvenient replacement of the doors, in order to minimize the man hours consumed by employees of banks that provide attendance to the customers, while the customers open their safe deposit doors, with a mechanical enhancement of blocking strength as well as an improvement of security over other processes, without a complex electrical contact system. 
     We have also noticed that authorized service mechanics often open locked mechanical safe deposit locks by first drilling a hole through the face of the cylinder plug, threading a sheet metal or self tapping screw into the hole and pulling the inserted screw with either a nose puller or claw hammer until the face of the cylinder breaks away to allow removal of the cylinder plug. The removal of the cylinder plug allows direct and immediate frontal manipulation of the tumblers until the lock is unlocked. Consequently, even though the faceplate of the safe deposit door may itself be strong enough to resist casual tampering, the susceptibility of the cylinder plug to quick removal by a single application of brute force deleteriously reduces the security of the entire drawer. 
     The Electronic Security System of U.S. Pat. No. 5,745,044 and U.S. Pat. No. 5,140,317 issued to Hyatt et al., is currently used to lock pay telephones. This design blocks a locking bolt, but does so from what we believe is a geometrically disadvantageous point. By virtue of the separate direct blocking of a bolt by a solenoid, the bolt is blocked off center from the centerline of the bolt. Moreover, the physically large lock cylinder and the inter-device discrete wiring between the solenoid and the other components inside the casing, as well as the electrical contact system for the lock cylinder, create several problems in our opinion. Furthermore, the difficulty of manufacture and installation of wiring, and the absence of both miniaturization and offsetting of the bolt blocking, suggest that there is little practical prospect of retrofitting the many existing offset nose locks. In addition, the routing and use of discrete wires causes problems of reliability and quality during manufacture and usage, absent tedious careful and consistent monitoring. 
     The rotatable keypad operated solenoid lock of Butterweck, et al, U.S. Pat. No. 5,845,523 for an Electronic Input And Dial Entry Lock, and the other various locks mentioned in that patent such as U.S. Pat. No. 4,831,851 for a Combination/electronic Lock System by Larson, U.S. Pat. No. 4,967,577 for an Electronic Lock With Manual Override by Gartner, et al, U.S. Pat. No. 4,899,562 for an Electronic Door Lock by Gartner, and U.S. Pat. No. 4,904,984 for a Combination Lock With An Additional Security Lock by Gartner, are variations of a dial operated combination lock, and lack the security, reliability and economy traditionally demanded for safe deposit boxes and drawers, while the Lock For A Safe-Deposit Box of Chieh-Chen Yen, et al., U.S. Pat. No. 5,495,733 inconveniently relies upon different keys for the renter of the safe deposit box and for the clerk of the bank, as well as a manually operated keypad. 
     SUMMARY OF THE INVENTION 
     It is therefore, an object of the present invention to provide an improved lock and process for restricting access to containers. 
     It is another object to provide a lock and process suitable for retrofitting containers previously secured by bitted and unbitted locks. 
     It is yet another object to provide a lock and process able to enhance the security of containers against unauthorized entry. 
     It is still another object to provide a lock and process able to electronically control access to the interior of secured containers. 
     It is still yet another object to provide a lock and process for electronically monitoring access to secured containers. 
     It is a further object to provide an electronically key controlled process and a cam assembly that may be configured as a single integrated electromechanical unit operable with an electronically controlled key, mated with either the existing lock cylinders of containers or with new lock cylinders, and retroactively fitted to secure those containers. 
     It is a still further object to provide an electronically key controlled process and integrated electromechanical cam assembly that may either be installed as a retroactively fitted component part of an existing locking mechanism with a minimum of modifications of the locking mechanism, or alternatively, be incorporated into a complete locking mechanism. 
     It is still yet a further object to provide an electronically key controlled process and integrated electromechanical cam assembly that may be retroactively installed as a component part of locking mechanisms previously installed in lockable containers by using existing screw patterns and key holes of those containers. 
     It is an additional object to provide an electronically key controlled process and integrated electromechanical cam assembly able to be mated with either bitted lock cylinders or with unbitted cylinder plugs. 
     It is a still additional object to provide an electronic cam and cam locking process endowed with simplified interconnections between the components of the lock, and that is amenable to simplified manufacture. 
     It is a yet additional object to provide an electronic cam and cam locking process endowed with an enhanced mechanical strength. 
     It is still yet an additional object to provide an electronic cam and cam locking process that indirectly blocks the cam. 
     It is also an object to provide a locking cam and cam locking process that drives and locks the bolt from its relative center. 
     These and other objects may be achieved with a process requiring either electronic conformance of a key to an electronic circuit carried by a cam driving a bolt or both mechanical conformance and electronic conformance of the key to both a cylinder plug and to the electronic circuit in order to enable the cam to drive the bolt between a locked position and an unlocked position. One embodiment may be constructed with a housing bearing an optimally positioned hole centered upon a first axis, a bolt supported by the housing and moving transversely relative to the first axis to protrude beyond the housing to an extended, and locked, position and to retract within the housing to a retracted, and unlocked, position, and the cylinder plug of the lock cylinder perforated by a centrally positioned keyway, having an exposed circumferential surface surrounding the keyway rotatably fitted within the optimally positioned hole, and rotating within the optimally positioned hole in response to rotational force applied by a key conformingly corresponding to the lock through an arc centered upon the first axis. A cam is positioned within the housing to rotate with the cylinder plug as the key conformingly corresponding to the lock manually applies a rotational force to the cylinder plug as the key is manually rotated through the arc. A member eccentrically positioned relative to the first axis, extends between the cam and the bolt to drive the bolt between the extended and the retracted positions as the cylinder plug is rotated through the arc. An electronic circuit containing a memory and a microprocessor, that is mounted upon and supported by the cam to rotate with the cam through the arc, determines electronic conformance of the key and operationally responds to digital data carried by the key to electronically activate a release mechanism that is spaced-apart from the cylinder and eccentrically positioned away from the first axis. The circuit is functionally activated by the electronic circuit in response to mechanical and electronic conformance between the key and both the cylinder plug and the electronic circuit, to move between a deployed position preventing rotation of the cam relative to the housing, and a released position accommodating the rotation of the cam relative to the housing. Optionally, the first axis may be positioned to locate the cylinder plug off-center and toward one side of the lock&#39;s casing while the cam is positioned to rotate around a second and different axis in response to rotation of the cylinder plug and either electronic conformance to an electronic circuit carried by the cam, or both mechanical conformance to the cylinder plug and electronic conformance to the electronic circuit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
         FIG. 1A  shows a plan view of a contemporary arrangement for a parking meter lock; 
         FIG. 1B  shows a side view of a cam customarily used in a contemporary parking meter lock; 
         FIG. 2  shows a detailed side elevational view of one embodiment of the present invention designed for retrofitting a parking meter lock; 
         FIG. 3  shows a top detailed view of a cam which may be used in the embodiment of  FIG. 2 ; 
         FIG. 4  shows a side elevational view of a contemporary parking meter fitted with an embodiment of the present invention; 
         FIG. 5  shows a cut-away side view of another embodiment of the present invention suitable for use with metal office furniture; 
         FIG. 6  shows a front elevational view of a drawer for office furniture fitted with the embodiment shown in  FIG. 5 ; 
         FIG. 7  shows a conversion plate incorporated into the embodiment of  FIG. 5 ; 
         FIG. 8  shows an electronic cam incorporated into the embodiment of  FIG. 5 ; 
         FIG. 9  shows an assembly of the conversion plate and electric cam incorporated into the embodiment of  FIG. 5 ; 
         FIG. 10  shows a side elevational view of a cam assembly suitable for installation into the container illustrated by  FIG. 5 ; 
         FIG. 11A  is a block diagram schematic illustrating electrical circuits that may be incorporated into the practice of the present invention; 
         FIG. 11B  is a block diagram schematic illustrating an alternative configuration of electrical circuits that may be incorporated into the practice of the present invention; 
         FIG. 11C  is a block diagram schematic illustrating another alternative configuration of electrical circuits that may be incorporated into the practice of the present invention with a plurality of contacts accessible through the keyway; 
         FIG. 11D  is a block diagram schematic illustrating another alternative configuration of the electrical circuits that may be incorporated into the practice of the present invention with a single contact accessible through the keyway; 
         FIG. 11E  is a block diagram schematic illustrating another alternative configuration of the electrical circuits that may be incorporated into the practice of the present invention using a drive spindle; 
         FIG. 11F  is a perspective view of a drive spindle for the embodiment illustrated by  FIG. 11E ; 
         FIG. 12  is an exploded view illustrating details of the embodiment of  FIG. 10 ; 
         FIG. 13  is flow chart illustrating the principles of operation of the present invention; 
         FIG. 14  is a front elevational view of a drawer fitted with an embodiment of the lock shown in  FIG. 10 ; 
         FIG. 15  is a cross-sectional view taken along sectional line XV-XV′ in  FIG. 17 , showing a fourth embodiment of the present invention equipped with a vault; 
         FIG. 16  shows a cover that may be attached to the embodiment of  FIG. 15 ; 
         FIG. 17  is a plan view showing the assembly of the embodiment illustrated in  FIG. 15 ; 
         FIG. 18  is a plan view showing the assembly with the cover illustrated in  FIG. 16  mounted upon the housing illustrated in  FIG. 17 ; 
         FIG. 19  is an end view of the embodiment shown in  FIG. 18 ; 
         FIG. 20A  is an exploded view showing the embodiment of  FIG. 19  incorporated into a safe deposit door; 
         FIG. 20B  is an assembled view showing a channel attached to the safe deposit door; 
         FIG. 21  is an end view of the assembly illustrated in  FIG. 20 ; 
         FIG. 22  is a front elevational view of the embodiment of  FIG. 21 ; 
         FIG. 23  is a front elevational view of a safety deposit door fitted with an embodiment of the present invention; 
         FIG. 24  is a plan view showing details of another embodiment constructed according to the principles of the present invention, while in a locked state; 
         FIG. 25  is a plan view of the embodiment shown in  FIG. 24 , while in an unlocked state with the bolt still extended; 
         FIG. 26  is a side, cross-sectional view showing the embodiment of  FIG. 24  in transition between locked and unlocked states; 
         FIG. 27A  is a cross-sectional view of a bitted cylinder plug that may be incorporated into the embodiment of  FIG. 24 ; 
         FIG. 27B  is a cross-sectional view of an unbitted cylinder that may be incorporated into the embodiment of  FIG. 24 ; 
         FIG. 28  is a plan view illustrating incorporation of a bitted cylinder plug incorporated into an embodiment constructed according to the principles of the present invention; 
         FIG. 29  is a cross-sectional view of the embodiment illustrated in  FIG. 28  showing a key prior to insertion; 
         FIG. 30  is a cross-sectional view showing operational aspects of the embodiment illustrated in  FIG. 28  with a mechanically conforming key inserted into its keyway; 
         FIG. 31  is a plan view showing another embodiment constructed according to the principles of the present invention with a heat sensitive paramagnetic re-locking mechanism shown in an unrelocked state; 
         FIG. 32  is a plan view showing another embodiment constructed according to the principles of the present invention with a heat sensitive paramagnetic re-locking mechanism shown in a re-locked state; 
         FIG. 33  is a side cross-sectional view of the embodiment illustrated by  FIG. 32  while in an unrelocked states; 
         FIG. 34  is a plan view showing details of still another embodiment constructed according to the principles of the present invention using a rotary solenoid; 
         FIG. 35A  is a cross-sectional view of the embodiment illustrated in  FIG. 34  equipped with an unbitted cylinder plug; 
         FIG. 35B  is a detailed cross-sectional view of a bitted cylinder plug that may be incorporated into the embodiment illustrated by  FIG. 34 ; 
         FIG. 36  is a plan view showing the embodiment of  FIG. 34  while in an unlocked state with the bolt shown retracted; 
         FIG. 37  is a partial assembly view showing an embodiment constructed according to the principles of the present invention with a non-bitted cylinder and a directly locking solenoid; 
         FIG. 38  is a cross-sectional view showing the assembly of the embodiment illustrated in  FIG. 37  equipped with an unbitted cylinder plug; 
         FIG. 39  is a cross-sectional side view showing the assembly of the embodiment illustrated in  FIG. 37 ; 
         FIG. 40  is a plan view showing the assembly of the embodiment illustrated by  FIG. 37 ; 
         FIG. 41  is a plan view showing a cover that may be installed upon the assembly illustrated by  FIG. 40 ; 
         FIG. 42  is a cross-sectional assembly view showing an embodiment constructed with a solenoid activated linkage; 
         FIG. 43  is a side cross-sectional view of the embodiment illustrated in  FIG. 42 ; 
         FIG. 44  is a plan view showing the embodiment illustrated by  FIG. 42 ; 
         FIG. 45  is a plan view of a cover that may be installed upon the cam assembly illustrated by  FIG. 44 ; 
         FIG. 46  is a cross-sectional elevation taken along sectional line XXIXVIII-XXIXVIII′ in  FIG. 48 , showing still another embodiment constructed according to the principles of the present invention and equipped with an unbitted cylinder plug; 
         FIG. 47  is a cross-sectional view of a bitted cylinder plug that may be incorporated into the embodiment illustrated by  FIG. 46 ; 
         FIG. 48  is a plan view of the embodiment illustrated by  FIG. 46  while in a locked state; 
         FIG. 49  is a plan view of the embodiment illustrated by  FIG. 48  while in an unlocked state; 
         FIG. 50  is a cross-sectional elevation showing the details of still yet another embodiment constructed according to the principles of the present invention and equipped with an unbitted cylinder plug; 
         FIG. 51  is a detailed cross-sectional view of a bitted cylinder plug that may be incorporated into the embodiment illustrated by  FIG. 50 ; 
         FIG. 52  is a plan view illustrating the embodiment of  FIG. 50  while in a locked state; 
         FIG. 53  is a plan view showing the embodiment illustrated by  FIG. 50  while in an unlocked state; 
         FIG. 54  is a plan view of another alternative embodiment constructed according to the principles of the present invention; 
         FIG. 55  is a cover that may be attached to the embodiment illustrated by  FIG. 54 ; 
         FIG. 56  is a cross-sectional elevation of the embodiment illustrated by  FIG. 54 ; 
         FIG. 57  is a side elevational view of the embodiment illustrated by  FIG. 54  equipped with an unbitted cylinder plug; 
         FIG. 58  shows a cross-sectional view taken along the sectional line in  FIG. 60 , of an alternative embodiment; 
         FIG. 59  shows a plan view of the embodiment of  FIG. 58 , when installed with a guide wall; 
         FIG. 60  shows a plan view of the cam assembly of  FIG. 58 ; 
         FIG. 61  shows a plan view of the embodiment of  FIG. 58 , as installed in a lock assembly; 
         FIG. 62  shows a cross-sectional view taken along the sectional line in  FIG. 61 ; 
         FIG. 63  shows a plan view of the embodiment of  FIG. 58  in an unlocked and opened position; 
         FIG. 64  shows a side view of a solenoid usable in the embodiment of  FIG. 58 ; 
         FIG. 65  shows a side view of the solenoid of  FIG. 64 ; 
         FIG. 66  shows an exploded isometric view of the embodiment illustrated by  FIG. 58 ; 
         FIG. 67  shows a top view of an assembled alternative embodiment while in the locked state; 
         FIG. 68  shows a top view of the embodiment of  FIG. 67 , while in an unlocked state; 
         FIG. 69  shows a top view of the embodiment illustrated by  FIG. 67  in a locked state, after the embodiment has been subjected to excessive keyway torque; 
         FIG. 70  shows a top view of still another alternative embodiment, while in a locked state; 
         FIG. 71  shows the embodiment illustrated by  FIG. 70 , while in an unlocked state; 
         FIG. 72  is a top view of the embodiment of  FIG. 70 , shown in a partially unassembled, unlocked state; 
         FIG. 73  is a side elevational view taken along the sectional line of  FIG. 72 ; 
         FIG. 73A  is a side elevational view taken along the sectional line of  FIG. 72 , to illustrate the transfer and board mounted spring pin; 
         FIG. 73B  is an enlarged side elevational view taken along the sectional line of  FIG. 72 , to illustrate the transfer and board mounted spring pin; 
         FIG. 73C  is an enlarged side elevational view taken along the sectional line of  FIG. 72 , to illustrate the transfer, insulating material and board mounted spring pin; 
         FIG. 73D  is a side elevational view showing the electrical and data path through the embodiment of  FIG. 70 ; 
         FIG. 74  is a top view of an assembled alternative embodiment while in an unlocked state; 
         FIG. 75  is a top view of the embodiment illustrated by  FIG. 74 , while in a locked state; 
         FIG. 76  is a top view of a partially unassembled alternative embodiment, illustrated in the locked state; 
         FIG. 76A  is a top view of the embodiment illustrated by  FIG. 76 , while in an unlocked state; 
         FIG. 76B  is a top view of the embodiment of  FIG. 76 , shown after application of excessive torque to the keyway; 
         FIG. 76C  is an enlarged side elevational view illustrating the electrical contact system and insulating material in the embodiment illustrated by  FIG. 76 ; 
         FIG. 76D  is an enlarged side elevational view showing the electrical and data path through the embodiment illustrated by  FIG. 76 ; and 
         FIG. 77  is a top view of an alternative embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning now to the drawings,  FIG. 1A ,  1 B illustrate the salient features of a hypothetical, conventional parking meter lock  100 . A metal cam plate  102  formed with a circular shape perforated by a D-shaped hole  104  engages a D-shaped extension of a locking cylinder plug  116 . A conically shaped, concave depression  106  extends toward the cylinder plug  116 , to enable D-shaped hole  104  to engage the extension. A pair of radially opposite helically spiral slots  108  equally distantly radially spaced-apart from D-shaped hole  104 , perforate plate  102  to engage and direct the travel of connecting pins  110 , thereby alternately withdrawing and projecting bolts  112  in opposite reciprocation in the opposite directions indicated by arrows A. Typically, a mechanically bitted key  50  is inserted into keyway  118  that axially perforates a cylinder plug  116  that is coaxially fitted inside the cylindrical shell  119  that surrounds plug  116 . Shell  119  is fitted into a re-enforced door (not shown) such as the circular door of a municipal parking meter. Correct correspondence between the lands and peaks of the bits of key  50  and the tumblers (not shown) within plug  116  create a shear line that enables the torque that is manually applied to the handle of key  50  to rotate plug  116  relative to shell  119 , thereby drawing pins  110  from a radially outwardly position shown in  FIG. 1A , to a radially inward position closer to the center of cam plate  102 . Once bolts  112  have been withdrawn, the door into which lock assembly  100  has been fitted can be removed, or opened. Rotation of key  50  in the opposite direction causes extension of bolts  112 , thereby locking the door. 
     In the embodiment of the invention shown in  FIG. 2 , cylinder plug  116  is encased in a cylindrical shell  120  made of a non-electrically conductive material. This shell electrically insulates plug  116  from the metal door into which lock assembly  101  has been installed. An extension  122  of cylinder plug  116  passes through D-shaped hole  104  in cam plate housing  126 , and makes mechanical and electrical contact with a board mounted spring biased electrical contact pin  136 . Compression spring  137  biases pin  136  toward the axial dimension of cylindrical plug  116 , thereby assuring electrical contact between pin  138  and extension  122  as plug  116  rotates within shell  120 . Electronic cam assembly  140  contains a second board mounted spring biased pin  138  forming mechanical and continuous electrical contact with at least one of the reciprocally sliding bolts  112 . 
     Cam plate  126  (having a base with a shape substantially identical to the top view of cam plate  102  shown in  FIG. 1B ), and cover  128  are preferably made of an electrically insulating material such as a plastic. Circuit board  139  supports a plurality of integrated circuits  142  and other electrical components, as well as electrical contacts  136 ,  138 . Bosses  132 , formed in a base of the cam plate housing  126 , receive threaded fasteners  134  extending through circuit board  139 , thereby securing circuit board  139  within cam plate housing  126 . 
     Turning to  FIGS. 3 and 4 , in conjunction with  FIG. 2 , when a key  500  corresponding to the security features (i.e., correctly bitted teeth, if the key is in fact bitted), is inserted into keyway  118  so that the blade  502  of the key serves as an electrical contact for transmission of data and power to contact  136 , while a spring loaded electrical contact  504  mounted on the other side of the head  506  of key  500  engages the circumferential exposed surface (often the exposed surface of a re-enforced insert)  409  of door  408 , thereby completing the electrical circuit between the electronic control circuit  508  of key  500  and electronic circuit  130  mounted on circuit board  139  via contacts  136 ,  138 . Assuming correct electrical conformity established through the power and data transferred between circuits  508  (including the supply of power to circuit  130  from circuit  508  via key  500  and cylinder plug  116 ), the logic and control components of circuit  130  will electrically activate solenoid release assembly  400  with the electrical current flowing through solenoid coil  402 , thereby withdrawing solenoid armature  404  upwardly in the drawing shown in  FIG. 2 , and thus removing armature  404  from slot  108 . This frees the length of slot  108 , thereby enabling pins  110  to travel along the arcuate lengths of corresponding slots  108  as a manual torque applied to key  500  rotates plug  116  and cam assembly  140 . In the normal locked position, shown in  FIGS. 2 and 3 , armature  404  obstructs one of the two slots  108 , thus preventing cam  126  from rotating and drawing bolts  112  inwardly. Solenoid assembly  400  may be mounted upon and supported by circuit board  139 . Cover  128  encases circuit  139  within the housing provided by the inner side of cam plate  126 , while pins  110  protrude into grooves  108 . Bolts  112  slide between guides  410  and the adjoining portion of door  408 . 
     Turning now to  FIG. 5 , an alternative embodiment is illustrated with a cam plate and housing  126  preferably made of an electrically insulating material, installed between a cylinder plug  412  and the rear wall  426  of the door of the item of furniture. Plug  412  is mounted with washer  422 , and is in contact with the front wall  424  of the door of the item of furniture, with keyway  118  aligned with hole  425  in front wall  424 . A pair of shear pins  414  extend between an extension  123  of cam plate  126  and fit into conforming apertures  415  in the base of cylinder plug  412 , thereby linking rotation of plug  412  with rotation of plate  126 . A single hole  413  is formed within rear wall  426 , in alignment with the armature  404  of solenoid  400 . In its inactive, normally inoperative state as shown in  FIG. 5 , armature  404  rests within aperture  413  under the bias of spring  406 . 
     A second hole  433  is formed in rear wall  426 , in substantial coaxial alignment with keyway  118 , to accommodate pivot post  430  of cam spacer post  431 , which serves to support cam plate  126  upon post  430 , thereby fastening the entire assembly against the rear wall  426 . A Truarc® ring  428  holds post  431 , together with plate  126 , against cam plate extension  432 . Drive pin  434  protrudes from the underside of cam plate  126  opposite circuit board  139 , and is received by a conforming aperture  435  within extension plate  432 . 
     Turning now to  FIGS. 6 through 10  in conjunction with  FIG. 5 , extension plate  432  protrudes beyond a slot  436  cut into the flange  427  extending between front wall  424  and rear wall  426 . When a hand held key conforming in shape to the interior of keyway  118  is fully inserted into keyway  118 , the blade of the key makes electrical contact with contact wiper  416  mounted upon circuit board  139  while an electrically separate contact pin spaced radially apart from the blade of the key makes electrical contact with the adjoining exposed surface of front wall  424  and, via electrical conduction through plug  412 , with contact wiper  418  also mounted upon circuit board  139 . Upon determination of electrical and logical compatibility of the key with circuit  130  mounted upon circuit board  139 , solenoid  400  is electrically charged to withdraw armature  404  from aperture  413 , thereby releasing cam plate  126  and plug  412  to rotate under the torque manually applied to the key, thereby enabling post  430  to rotate within aperture  433 , thus allowing drive pin  434  to rotate about the axis of post  430  and thereby drawing extension plate  432  in a direction of arrow B shown in  FIG. 6 , through slot  436 , thereby allowing door assembly  423  to be opened. 
     Turning now to  FIG. 11A , block diagrams illustrate electronic circuit  130  for the cam assembly and electronic circuit  508  for the corresponding electronic key assembly  500  mechanically and electrically conforming to cylinder plug  116  and its electronic circuit  130 . Circuit  508  is constructed within the head  506  of key  500  or, alternatively, into a portable housing electrically coupled to key  500 . As shown in  FIG. 11A , a replaceable battery (e.g., a 3.3 volt button battery) may be removably encased in the head  506  of key  500 , with the positive plurality coupled in common to one side of electronic signal filter  526  and the bitted blade  502  of the key. In this embodiment, blade  502  is mechanically cut with teeth  510  and channels  511  conforming to keyway  118 . Blade  502  is positively charged by battery  437 , and makes electrical contact with, and provides transmission of both power and data to circuit  130  via flexible contact wiper  136  mounted upon circuit board  139 , which is, in turn, coupled to input/output stage  542 . A local ground return between circuit  130  and circuit  508  is provided via flexible spring loaded electrical contact  138  making electrical contact with bolt  112  which, in turn, makes electrical contact with the electrically conducting door  408  of the container; a spring loaded pin  507  extending from the head  506  of key  500  rides upon and makes electrical contact with door  408 . 
     Circuit  508  may be constructed with a microprocessor  512  driven according to a programs stored in read only memory  514 , using data transient in random access memory  516 . A clock  518  provides synchronization to microprocessor  512 , while input/output stage  522  services as a buffer enabling microprocessor  512  to drive signal generator  524 . Circuit  508  is electrically powered by battery  437 . 
     When key  500  has been fully inserted into keyway  118 , blade  502  makes electrical contact with spring biased data and power contact  136 , while the radially spaced-apart spring bias contact  504  serves as a ground return making electrical contact with the surrounding region  409  of door  408  and, through bolt  112 , electrical contact  138  and input/output stage  542 . Within logic and control circuit  130  of the cam assembly, microprocessor  530  operates according to a program stored within read only memory  534  using data written into and read from random access memory  536 . Counter  538  is coupled to microprocessor  530 . Communication between the logic circuit  130  and contacts  136 ,  138  are conducted through input/output stage  542 . A switch  544  is driven by input/output stage  542  under control of microprocessor  530  upon a determination by microprocessor  530  that key  500  holds a digital signature that electronically conforms to data stored within the circuit borne by circuit board  139 , to provide electrical current through solenoid coil  402  and thereby retract armature  404  or, alternatively, if the solenoid is constructed as a stepping motor, to energize coil  402  and thereby rotate armature  404 . The circuit illustrated in  FIG. 11A  is particularly suitable for retrofitting secured containers such as existing stand-alone, municipal curbside parking meters. 
     Turning now to  FIG. 11B , key assembly  500  has a blade  502  without bits or channels, bearing a centrally positioned electrical data and power contact  716  coupled to the positive polarity of battery  437 . Contact  716  is electrically insulated from the exterior surface of blade  502 . Blade  502  serves as the negative ground return via electrical contact  418  while contact  716 , serves as the power and data connector when fully inserted into keyway  118 , to make electrical contact with flexible spring contact  416 . Flexible, spring type electrical contact wipers  416 ,  418  may be surface mounted upon circuit board  139 , in positions to make electrical contact respectively with contact  716  via keyway  118  and the electrically conducting cylinder plug  412 . Solenoid winding  402  is either surface mounted on, or supported by, circuit board  139 . 
     As illustrated by  FIG. 11C , the electronic circuit for the cam assembly may be equipped with its own local power supply in the form, for example, of a replaceable battery (not shown) installed on and wholly borne by circuit board  139  to provide a constant voltage to circuit components such as microprocessor  530 , memories  534 ,  546 , counter  538 , and input/output stage  542 , and to provide a source of electrical power for energizing coil  402  of the solenoid via switch  544 . In this configuration the cylinder plug is not required to serve as a ground electrical path for the connection between the key and lock circuit  139 . Use of an earth ground would be incidental. Leads  416 ,  418  are plated copper conductors formed on the circuit board  139 , with lead  418  serving as a local ground terminal. On key circuit  508 , pin terminal  502 A serves as a ground conductor; terminal  502 A may be a spring loaded pin or a flexible connection, positioned to make electrical contact with lead  418  when the blade, or shank  502 , of key  500  is conformingly inserted into the aperture of keyway  118 . A spring loaded ball bearing may be inserted within keyway  118  to mate with a corresponding dimple in shank  502 , and serve as a key retainer when key  500  rotates keyway  118  out of its rest position. Terminal  502 A may be connected without electrical insulation to shank  502 , thereby connecting circuit  508  via shank  502 . Pin terminal  716  serves that same function as shown in the embodiment illustrated by  FIG. 11B , and is electrically insulated from shank  502  in order to conduct data signals and provide a positive potential to circuit  139  via lead  416 . 
       FIG. 11D  illustrates an alternative embodiment with the cylinder plug  412  serving as an electrical ground path for electrical connection between key circuit  508  and lock circuit  139 . Lead  416  is a copper lead plated upon circuit board  139 , and is directly accessed by terminal  716  via keyway  118  to electrically conduct, for example, a positive potential and data signals. The key blade, or shank  502  serves as the ground terminal for key circuit  508 . Terminal  716  is electrically insulated by shank  502  serves to electrically conduct a position potential and data signals in the same function as in the embodiment illustrated by  FIG. 11B . 
       FIG. 11E  illustrates an alternative embodiment bearing a keypad  520  that is exposed to manual activation by a user. A drive spindle  502 ′, rather than a key blade, is used to apply torque to the electronic cam that bears and encases circuit  139 . Once the drive spindle  502 ′ has been electrically connected with the electronic cam circuit  139  via keyway  118 ′, the spindle  502 ′ may be left within keyway  118 ′ and removed only for service and such maintenance as replacement of battery  437 . Accordingly, with the exception of replacement of battery  437 , lock circuit  139  would be continuously powered by battery  437  borne by key circuit  508 . In this embodiment, lock circuit  139  could be equipped with merely a clock  528 , while key circuit  508  contains a counter  538 . As illustrated by  FIG. 11F , drive spindle  502 ′ may be constructed with an engagement keyslot  502   b  extending either partially, or wholly, the length of shank  502 ′, to engage a corresponding detent within keyway  118 . Spindle  502 ′ may itself serve as an electrical conductor such as the ground return, that engages electrical lead  418  of lock circuit  139 , while a second electrical conductor  716   b  extends the length of spindle  502 ′ and is electrically insulated from the body of spindle  502 ′ by insulation  716   c . Conductor  716   b  may be constructed as either a circuit board with a tin, copper or gold plated trace, or an electrically conducting trace itself deposited directly upon insulation  716   c . Conductor  716   b  could be set, after encased in electrical insulation, into a metallic spindle or encased in an electrically conductive plastic spindle may, for example, of carbon filled polymer. 
     When assembling the electronic cam, electrically conductive cylinder plug  412  bearing apertures  415 , is positioned to receive within the apertures  415 , corresponding shear lock pins  414  extending outwardly from cover  128  for the housing formed by cam plate  126 . The solenoid release assembly  400  is mounted on circuit board  139 , and circuit board  139  is in turn inserted within the circumferential walls  131  of cam plate  126 , with surface mounted flexible spring electrical contact  416  centrally positioned to extend through cam plate extension  123  and into the vacant portion of keyway  118  in order to make electrical contact with the power and data conductor of the corresponding key. Contact  416  is surrounded by an electrical insulator  420  to prevent contact  116  from making electrical contact with either extension  123  or with electrically conducting plug  412 . Cam spacing post  431  and pivot post  430  are concentrically positioned and coaxially aligned with keyway  118 , to protrude from plate  126  toward the bolt (not shown in  FIG. 12 ), while drive pin  434  extends axially in the same direction toward a corresponding aperture in the bolt. 
     In an operation, the key is inserted into the keyway as shown in step  550  of  FIG. 13 . Power is supplied from battery  437  via contact  136  to cam circuit  130 , and data is written via contact  136  into memory  536 . A comparison is then made by microprocessor  530  and if the data carried by the key is not electronically conforming to data held by circuit  130 , in step  550  circuit  130  ignores the presence of the key. Alternatively, if the key is found by circuit  130  in step  554  to be electronically conforming, in step  558  circuit  130  applies power to switch  544  and solenoid (or motor)  400  to release cylinder  116  to the rotational torque manually applied by the key to the lock, thus enabling in step  560  rotation of the cylinder in response to the manual torque, and thereby resulting in opening of the lock in step  562 . 
     In  FIG. 14 , a drawer of an item of furniture is fitted with a lock constructed according to the principles of the present invention, with a carrier housing  438  serving as the rear wall, attached to flange  427  via threaded fasteners  439 . This allows for a modular improvement using an embodiment of the present invention as a separate item installed within the furniture. 
     Turning now to  FIG. 15 , an alternative embodiment of the present invention is shown with a construction particularly suitable for installation in a safety deposit box door within a bank vault. An aperture  433  in the rear wall of housing  440  for a lock, accommodates insertion and operational rotation of pivot post  430 . The shank  113  of bolt  112  lies upon the inside surface of housing  440 . Aperture  608  in shank  113  accommodates spacer  431  while aperture  606  accommodates drive pin  434  to force shank  113  to slide against the interior surface of housing  440 . 
     Looking now to  FIGS. 15 ,  16  and  17  in combination, insertion of an electrically conforming key into keyway  118  will, after electrical exchange of data via power and data conductor  416 , enable circuit  130  mounted upon circuit board  139  to energize the coil of solenoid  400  and withdraw armature  404  against the force of return compression spring  406 , thereby enabling torque manually applied by the key to cylinder plug  116  to rotate cam plate extension  123  and in turn, cam plate  126 ; as cam plate  126  rotates about pivot  430 , drive pin  434  engages the surface of slot  606  formed in shank  113 , and as the clockwise rotation of the torque applied to cam plate  126  drives drive pin  434  through a clockwise arc, drive pin  434  travels through slot  606  while forcing shank  113  to the right in  FIG. 17 , thereby retracting bolt  112 . Subsequent counterclockwise rotation of the key to the position shown in  FIG. 17 , enables spring  406  to force armature  404  back into slot  413  after termination of the electrical current through the coil of solenoid  400 . Cover  442  may be attached to housing  440  by threaded fasteners  439 . 
     Considering  FIGS. 15 through 23  collectively, the assembled housing  440  with cover  442  and protruding flanges  446  exposed on opposite sides of housing  440 , may be received within channel  454  to enable set screws  452 , or other detents, to be inserted within set screw detents  448 . Once channel  454  is securely attached to the thin safety deposit door  456  with D-shaped key hole  458  aligned substantially coaxially with plug clearance hole  460  as shown in the assembled view of  FIG. 20B , cylinder plug  116  will be substantially coaxially aligned with plug clearance hole  460  and D-shaped key hole  458  of channel  454  and door  456 , respectively. As shown in the elevation view of  FIG. 22 , this enables bolt  112  to protrude substantially beyond the left side of the door while in the locked position. Consequently, the entire lock assembly  140  as well as the pins  462  for door  456 , are concealed, with only board mounted data and power electrical contact  416  visible through keyway  118 , as is more apparent from  FIG. 23 . 
     Turning now to  FIGS. 24 through 27 , an alternative embodiment constructed with a pair of electrically conductive attachments  610 , one of which is mounted upon circuit board  139  and one of which is mounted upon unlocking detent  622 , terminate opposite ends of the length of relatively thin wire made of a paramagnetic alloy of a shape-memory alloy such as a NiTiNol wire  614 . The locking device  600  is constructed with a cover  442  having a pair of spaced-apart, oppositely facing arcuate guide walls  602  partially surrounding circumferential wall  131  of cam plate  126  to form a shell. A groove  613  formed into one of the guide walls  602  conforms to the shape of spherical ball  604  over an arcuate length of less than one half of the circumference of ball  604 . Ball  604  is positioned principally upon cam plate  126  and spaced equally distantly between a pair of rectangular guides  605 , to extend through a gap in circumferential wall  131 . An unlocking detent  622  is held in position by an electrically conductive compression spring  616 , between guides  605  on one side, and guide wall  624  on its other side. Plate  620  also contains a circular concave groove  622  circumferentially conforming to the exterior of ball  604  with a greatest depth of less than one half the diameter of ball  604 . A proximal end of locking plate  622  is attached to conductive attachment  610 . 
     In operation, a manual key electronically conforming to circuit  130  after insertion into keyway  118  and making electrical contact with conductives  416 ,  418 , enables circuit  130  to apply electrical current between attachment  610 ; the electrical current causes the NiTiNol alloy wire  614  to contract, thereby drawing locking plate  622  upwardly against the force of compression spring  616 , as shown in  FIG. 25 , thereby enabling the manual torque applied by the key to cam plate  126  to force ball  604  to roll out of groove  613  and to roll into groove  622  in a direction shown by arrow B as cam plate turns clockwise in a direction indicated by arrow C. The clockwise movement of cam plate  126  causes drive pin  434  to travel along slot  606 , thereby forcing shank  113  to the right in a direction of arrow D as shown in  FIG. 25 , thus retracting bolt  112  substantially into the interior of housing  440 . Cam rotation and withdrawal of the key from keyway  118  terminates access, by causing interruption of electrical current through NiTiNol alloy wire  614 . Referring again to  FIGS. 11A ,  11 B, software stored in ROM  534  may instruct microprocessor  530  after a certain number of pulses from counter  538  to change switch  544  to its rest state, causing interruption of power through NiTiNol alloy wire  614 . This enables spring  616  to force locking plate  620  downwardly to discharge ball  604  alternately into groove  613  of guide wall  602 . Simultaneously, the cam clockwise rotation opposite to the direction shown by arrow C in  FIG. 25 , forces drive pin  434  against the wall of slots  606 , thereby causing shank  113  to travel in the opposite direction shown by arrow D, thus ejecting bolt  112  and locking the door to which the assembly has been attached. 
       FIG. 27B  shows a bitted cylinder  700  fitted with a cylinder plug  704  which may be incorporated into the embodiment represented by  FIGS. 24 through 27A . In this embodiment, the key (not shown) can be configured with a plurality of teeth cut to conform to the shear lines  707  formed by the relative length of bottom pins  706  and top pins  708  within cylindrical shell  702 . As shown in  FIG. 27B , compression spring  710  holds bottom pins  706  and top pins  708  inwardly to prevent rotation of cylinder  704  relative to shell  702 . A Truarc® ring  428  holds cylinder  700  within cover  442 . With this alternative embodiment, the key must both mechanically conform to the shear line established by pins  706  and  708  and electronically conform to the digital signature required by circuit  130  before access can be obtained. As shown in  FIG. 28 , a fixed pin  712  holds the extreme wall of shell  712  fixed into position relative to circumferential wall  131  that forms a cylinder housed within and rotatable within the shell formed by guide walls  602 . 
     Turning collectively to  FIGS. 24 through 36 , a sphere  630  of an electrically conductive material (preferably, with a polished exterior surface such as a chrome plated ball bearing, may be inserted into spacer  123  within a spherically conforming recess, under electrical contact  416  between the open portion of keyway  118 , namely  632 , and circuit board  139 . Sphere  630  has unrestrained multiple degrees of freedom of rotation. Consequently, sphere  630  blocks direct access to circuit board  139  and, among other advantages, deters efforts to defeat locking device  600  by drilling for example with a rotating bit inserted into keyway  118 . Accordingly, and as may be seen in  FIGS. 29 and 30 , electrically insulated central electrical contact  716  of key  500  makes electrical contact with contact  416  directly, and sphere  630  is interposed between contact  416  and an extension of keyway  118  through spacer  123 , to protect circuit board  139  from damage caused by improper access such as drilling through keyway  118 . 
     Turning again to  FIGS. 29 and 30 , when bitted key  500  is coaxially inserted into keyway  118  of a bitted cylinder plug  116 , the bitting of key  500  radially displaces top and bottom pins within shell  702 , and if there is a mechanical conformance between the bitting of the teeth and the shear line between the top and bottom pins, electronic conformance between circuit  508  of the key and circuit  130  formed on circuit board  139  will enable the battery  437  held by the head  506  of key  500  to apply electrical power via spring pin key data contact  716  and contact wiper  416  to paramagnetic alloy wire  416  extending between connectors  610 , thereby contracting wire  416  and drawing locking plate  620  upwardly to receive a less than hemispheric exterior surface of ball  604 , thereby allowing cam plate  126  to rotate under the torque applied by the key  500  relative to guide wall  602 . Formation of groove  613 ,  620  with depths of less than one radius of bearing  604 , in preferably less than one half of the radius of bearing  604 , enables the torque applied manually to key  500  to force bearing  604  out of the corresponding groove  613  or unlocking detent  622  once plate  620  has been positioned by either spring  616  or paramagnetic wire  614 . 
     Turning now to  FIGS. 31 through 33 , not infrequently heat is applied to the keyway  118  in an improper effort to influence the behavior of the locking mechanism through thermal expansion caused by application of the heat. Paramagnetic alloys are especially responsive to heat. Therefore, in the embodiment illustrated a re-locking lever  720  is superimposed alongside locking plate  620 , with a pivot  728  rotatably attaching lever  720  to the upper surface of guide wall  624 . Re-lock lever  720  has a bell crank shape with one arm attached to a second paramagnetic alloy wire  724  extending between fasteners  726 ,  727 . Application of heat to the cam assembly via keyway  118  will cause wire  724  to contract, thereby pulling the proximal end of lever  720  downwardly as shown in  FIG. 32 , thus forcing the distal end of lever  720  to engage slot  722  formed within locking plate  620 . This prevents plate  620  from moving in response to contraction of wire  614  due to either application of an electrical current or heat. Consequently, improper efforts to open the locking mechanism via application of heat through keyway  118  are thwarted because locking plate  620  remains under the influence of spring  616 , thereby preventing bearings  604  from leaving slot  613  within guide wall  602 . 
     Turning now to  FIGS. 34 through 36 , the cam assembly  800  fitted with an electrically operated motor incorporated into the locking mechanism is illustrated. The motor is constructed with a shaft  808  supporting a drum  802  bearing a slot  804  formed through its upper surface that is sufficiently wide to accommodate passage of the arcuately curved fence  812  protruding downwardly from the under side of cover  422 . Mechanical and electronic conformity of a key inserted into keyway  118  will enable circuit  130  to apply an electrical current to the coil  814  of the stepping motor, thereby turning the armature  816  of the motor by ninety degrees to an unlocked state accommodating passage of fence  812  as shown in  FIG. 36  as cam plate  126  rotates. Shaft  808  can rest in the motor housing  810 , which is in turn mounted upon circuit board  139  or, alternatively, directly upon cam plate  126 . As shown in  FIG. 34 , drum  802  contains a false notch (shown on one side)  806  designed to accommodate entry, but not passage of a short portion of fence  812 . This thwarts improper efforts to unlock the mechanism simply by application of rotational torque to the cylinder plug as, by insertion of the blade of a screw driver into keyway  118 . Counterclockwise rotation and removal of the key will trigger application of a charge held by a capacitor within circuit  130  that has been charged by battery  437 , to rotate locking drum  802  by one additional ninety degree step in the clockwise direction to block rotation of cam plate  126  relative to fence  812 . Alternatively, the motor may be fitted with a torsion spring (not shown) anchored to the drum  802  and motor body  810  to restore the drum to its original locked position. 
     As shown in  FIG. 35B , a bitted cylinder plug  700  may be incorporated into the cam assembly of  FIGS. 34 and 35A , to provide an additional level of mechanical conformance required to gain entry to the container closed by the locking mechanism. 
     Turning now to  FIGS. 37 through 41  collectively, a non-bitted cylinder plug  116  is mounted to a cam assembly extension  123  via shear pins  414  received within conforming apertures  415  in a cylinder plug. A solenoid  400  is mounted directly upon circuit board  139 , as an interval component of circuit  130 , and is received within cavity  405  of cam plate  126 ′. Lock housing  440 ′ has one wall perforated by an opening  441  conforming in size and shape to solenoid armature  404 . In the lock state therefore, spring  406  holds armature  404  within aperture  441 . Correct mechanical conformance and electronic conformance between the key inserted into keyway  118  and circuit  130  will enable application of an electrical current to solenoid  400  that will cause withdrawal of armature  404  from aperture  414 , thereby enabling cam plate to rotate clockwise (as shown in  FIG. 40 ) under the torque applied by the key to keyway  118 , thus withdrawing shank  113  under the force of drive pin  434  applied to slot  606 , and thus withdrawing bolt  112 . Clockwise rotation of the key will restore alignment between armature  404  and aperture  441 . 
     Turning now to  FIGS. 42 through 45 , an alternative embodiment is constructed with solenoid release assembly  400  mounted upon circuit board  139 , to protrude through slot  901  formed in cover  128 . A lever  903  pivotally attached at a distal end to cam plate  126 ′ via a rotating pin  906 . Armature  404  is connected, at its distal end, via pin  904  to lever  903 . Pin  904  slides within a slot  908  extending nearly longitudinally along a distal portion of lever  903 . The distal end of lever  903  is terminated by a detent  902  conforming to aperture  441 . Accordingly, when spring  406  forces armature  404  to its fully extended position as shown in  FIG. 44 , lever  903  forces detent  902  fully within aperture  441 , thereby preventing rotation of cam plate  126 ′ relative to shank  113 . Consequently, efforts to apply a manual torque to via keyway  118  to cam plate  126 ′ will, absent electronic conformance of the circuit held by the key with circuit  130  mounted on cam plate  126 ′, will cause detent  902  to round the circumferential surface of aperture  441 , thus preventing rotation of cam plate  126 ′. Given electronic conformance between circuit held by the key and circuit  130  however, electrical current running through solenoid  400  will retract armature  404  within solenoid  400  against spring  406 , thereby compressing spring  406  while withdrawing detent  902  from aperture  441 , thus enabling clockwise rotation of cam plate  126 ′ relative to shank  113  and housing  440 ′. This rotation causes drive pin  434  to engage the walls of slot  606  and force shank  113  along the walls of spacer  431 . Consequently, slots  608  slides along the circumferential walls of spacer  431 , thus withdrawing bolt  112  substantially into the interior of housing  440 ′. Cover  442  fits upon and may be fastened with threaded fasteners to housing  440 ′. 
     It may be noted that this structure provides an indirect locking mechanism with detent  902 . Moreover, the radial displacement of detent  902  from the central axis of keyway  118  provides an enhanced advantage in the amount of torque required to mechanically defeat the lock. Additionally, the increased diameter of pin  906  pivotally coupling the distal end of lever  903  to the peripheral of cam plate  126 ′ further enhances a mechanical strength of locking mechanism. 
     Turning now to  FIGS. 46 through 49 , an alternative embodiment is constructed using a solenoid  400  mounted upon cam plate  126 . Solenoid  400  drives a locking plate  1006  reciprocally between a pair of radial extensions  1031  of circumferential wall  131  which forms a cylinder housed within and rotatable with respect to the shell, against the force of compression spring  406 . Spring  406  is mounted between the cap  405  terminating one end of locking end  1006 , and the side of upper extension wall  1031 . Locking plate  1006  is partially perforated by blind false notch  806  positioned to be axially aligned with and to receive the distal end of shaft  1007  of plunger  1002  when solenoid  400  is un energized and in its rest position as shown in  FIG. 48 . When a mechanically conforming key is inserted into keyway  118  and the digital electronic signature borne by that key conforms to data stored within circuit  130 , solenoid  400  is energized to retract plate  1006  in a downward direction, as shown in  FIG. 48 , and unlocking slot  804  is axially aligned with the distal end of shaft  1007 , as shown in  FIG. 49 . 
     Guide plate  1004  extends transversely between radial extension walls  1031 , and is perforated by a through aperture accommodating entry in partial passage of the enlarged proximal end of shaft  1007 . Return spring  407  acts against plate  1004  to hold plunger  1002  within groove  413  formed in guide wall  602 . The distal doubled end surfaces  1003  of plunger  1002  conform with the shape of groove  413  to form an obtuse angle at its apex, thereby enabling application of manual torque to keyway  118  to force, through camming action between surfaces  1003  and the walls of groove  413 , plunger  1002  to the left as shown in  FIG. 48 . Consequently, absent electronic conformance between the digital electronic signature held by the key inserted in the keyway  118  and data stored within the memory of circuit  130 , the distal end of shaft  1007  will engage false notch  806 . This is frequently the situation when a person seeking unauthorized access to the container secured by the locking mechanism attempts to simultaneously jar solenoid  400  while overcoming the bias force created by spring force  406 . The much larger force created by return spring  407  however requires a substantial jarring motion applied to the container, with result that the plunger  1002  tends to move suddenly and thereby overcome the bias force of return spring  407 , with result that the distal end of shaft  1007  engages false notch  806 . Electronic conformance between the signature held by the key and data stored within the memory of circuit  130  enables radially inward movement of shaft  1007  through aperture  804 , thereby enabling the manual torque to rotate cam plate  126  clockwise as shown in  FIG. 49 . The apex of surfaces  1003  rides along the inner circumferential surface of guide wall  602 . 
     Turning now to  FIGS. 50 through 53 , an alternative embodiment is shown constructed with an elliptical bolt drive lobe  1008  positioned between post  430  and cam plate  126 . This embodiment eliminates the need for a separate, discrete bolt drive pin  434 . Instead, the configuration shown relies upon camming action between surface  1011  of lobe  1013  to rotate through ninety degrees while engaging retract surface  1012  as manual torque is applied to a key that mechanically and electrically conforms to keyway  118  and circuit  130 , as the key is turned counterclockwise (looking at  FIGS. 52 and 53 ). This enables the camming action between surfaces  1011 ,  1012  to draw shank  113  to the right (as shown in  FIGS. 52 and 53 ), thereby withdrawing bolt  112  substantially within housing  440 . In an alternative configuration, the bitted plug  704  may be substituted for cylinder plug  116 , to add an additional element of access security. 
     Turning now to  FIGS. 54 through 57  show yet another alternative embodiment constructed with a cam plate  126 ″ having a centrally positioned spacer  431  and pivot post  430  coaxially aligned with the keyway  118  of cylinder plug  116  mounted upon cover  128  via spacer  123 . Cam plate  126 ″ is equipped with a downwardly depending drive pin  434  radially offset from the central axis of keyway  118 . A notch  1113  is formed at an intersection of two sides of plate  126 ″ separated by spacer  431  from bolt  112 . Notch  1113  engages blocking plate  1107  mounted on the distal end of armature  404 . Solenoid  400  is mounted upon the floor of housing  440 , rather than upon cam plate  126 ″. A pair of electrical leads  1018  coupled to plug  1012  electrically engage a pair of jacks  1016  mounted upon circuit board  139 . Leads  1018  flex as cam plate  126 ″ rotates through an approximate forty five degree arc in response to manual torque applied by a key inserted into keyway  118  when the key mechanically and electronically conforms to keyway  118  and circuit  130 . 
     Mechanical conformance of the key to keyway  118  and electronic conformance of the electronic digital signature held by the key to digital data stored within circuit  130  enables circuit  130  to apply an electrical current derived from the battery held by the key (or alternatively, by a battery mounted within circuit  130 ) to the winding of solenoid  400  via leads  1018 , thereby retracting armature  404  and locking plate  1101 , and thus allowing counterclockwise rotation of cam plate  126 ″ under the force of the torque of the key. This causes drive pin  434  to force the walls of slot  606  to the right as shown in  FIG. 54 , thereby shifting shank  113  and bolt  112  to the right, thus withdrawing bolt  112  substantially within housing  440 . Cover  442  is secured to housing  446 . As shown in  FIG. 57 , plug  1020  may be easily removed from jacks  1016  to enable and easy replacement of solenoid  400 . 
     Turning now to  FIGS. 58 through 65 , an alternative embodiment of a cam assembly is illustrated with a cam plate  126 ′″ supporting the circuit board  139  containing an electronic circuit such as  130  ( FIG. 11B ). Power and data electrical contact wiper  416  is centrally positioned across the longitudinal axis (which extends out of the plane of the paper) while ground contact wiper  418  is spaced regularly apart from contact wiper  416 . Shear pins  414  may connect a cylinder plug  116  with a centrally disposed boss  1218  formed within cam plate  126 ′″. An elliptical bolt drive lobe  1008  extends axially downwardly from the lower surface of cam plate  126 ′″, to support a much smaller pivot post  430  that is symmetrically positioned around the longitudinal axis F of keyway  118 . Elliptical lobe  1008  is situated within slot  1010  centrally formed within shank  113 . The central boss  1218  of cam plate  126 ′″ has a series of spaced-apart side walls  1210 ,  1212  and  1214  connected by an inwall  1215 , loosely accommodating a cam locking bolt  1200 , while allowing cam locking bolt  1200  to reciprocate radially relative to central axis F. A spring  1206  is compressed between end wall  1215  and the central inside portion of cam locking bolt  1200 , thereby holding nose  1208  of cam locking bolt  1200  outwardly protruding to engage an arch  1222  formed in a guide wall  1220  of housing cover  1240 . 
     Solenoid  1202  blocks cam locking bolt  1200  with oppositely extending coaxially positioned armatures  1204  which, when solenoid  1202  is de-energized, extend axially outwardly as shown in  FIG. 60  in order to place the cam assembly in the locked position. Solenoid  1202  may be constructed with a single annular wound coil driving both armatures  1204  in opposite coaxial directions. Mechanical conformance of the key inserted into keyway  118  and electronic conformance of the digital signature held by the key with the memory of circuit  130  (not separately shown) mounted upon circuit board  139  will enable circuit  130  to apply an electrical current to the coil of solenoid  1202 , thereby retracting both armatures  1204  against compression spring  1216 . This enables the manual torque applied by the key to keyway  118  in a clockwise direction, to cam nose  1208  of cam locking bolt  1200  out of arch  1222  and thus accommodate clockwise rotation of cam plate  126 ′″ against the bias force of spring  1206 , as shown by  FIG. 63 . 
     While energized by circuit  130 , solenoid  1202  withdraws armatures  1204  by a sufficient distance to allow the distal ends of armatures  1204  to an axial length less the distance between opposite side walls  1212 . In a locked, unenergized state solenoid  1202  has armatures  1204  extending to coaxial length somewhat less than the separation between opposite side walls  1210 ; it is the energization of solenoid  1202  that retracts solenoid  1202  to an axial length less than least distance separating side walls  1212 . In one embodiment, each armature  1204  extended approximately 0.130 inches while solenoid  1202  was de-energized, but extended only 0.050 inches while solenoid  1202  was energized. Wire leads  1228  electrically coupled the coil of solenoid  1202  to circuit  130 . It may be seen therefore, that counterclockwise rotation of the key placed within keyway  118  will enable nose  1208  of cam locking bolt  1200  to reciprocate regularly outwardly into arch  1222  prior to withdrawal of the key. 
     In an embodiment illustrated by  FIG. 66 , an alternative to the construction of the embodiment of  FIGS. 58 through 65  is shown with a pair of compressible springs  1206   a  being substituted for the single compressible spring  1206 . Each spring  1206   a  is seated within a different recess  1210  to bias a boss  1208   a  of cam nose  1208  toward engagement against guide wall  1220 ; the rotary force of manual rotation of a conforming key within keyway  118  overcomes the combined bias forces of springs  1206   a , and enables reciprocal displacement of cam nose  1208  from engagement within arch  1222  and, ultimately, movement of shank  113  and the concomitant withdrawal of bolt  112  toward the interior of casement  440 . 
       FIGS. 67 through 69  illustrate an assembled alternative embodiment of the principles of the present invention with an articulated lever  1300  operationally coupling cylinder plug  116  with cam plate  1260  while the shank  113  of bolt  112  is held by drive lobe  1008  mounted on cam plate  126  in a locked state, extending outwardly beyond the adjacent wall of casement  440  for the lock. Cylinder plug  116  is positioned toward the lower left interior of casement  440 , to rotate around a first axis M that is laterally offset from cam plate  126 . Cam plate  126 , which may, in a particular embodiment, be the same assembly as cam plate  126 ′″ illustrated in  FIG. 66 , albeit without spacer  123  and with cylinder plug  116  being separately and independently mounted along axis M, is positioned within casement  440  to rotate around a second axis N that is preferably parallel, and laterally (or, more accurately, radially) offset from first axis M. Referring briefly to the views of alternative embodiments provided by, for example,  FIGS. 73 ,  73 A through  73 D,  76 C and  76  D, circuit board  139  is mounted upon, and borne by, cam plate  126 . Circuit board  139  carries the individual components of circuit  130  and, optionally, a battery. An electrical contact is formed on circuit board  139  beneath the head of threaded fastener  1013 , and an electrically conducting substrate  1508  lies beneath cam plate  126 . Cam plate  126  is pivotably mounted between lower spacer  1431  and upper spacer  1441 . Spacers  1431 ,  1441  are respectively supported by lower pivot post  1430  and upper pivot post  1440 , that are rotatably seated within recesses formed, respectively, within the base of casement  440  and cover  128 . 
       FIG. 68  shows a top view of the embodiment of  FIG. 67 , while in an unlocked state with bolt  112  drawn by clockwise rotation of lobe  1008  against recess  1010  within shank  113 , into the interior of casement  128 . In this embodiment, lever  1302 , in combination with arm  1304 , operationally connects cylinder plug  116  with cam plate  1260 . Lever  1302  is joined, preferably in a non-rotating relation, to and extends radially outwardly from, cylinder plug  116 . Alternatively, lever  1302  may be pivotally coupled to cylinder plug  116  to experience a limited degree of lost motion prior to following any rotation experienced by cylinder plug  116 . The distal end of arm  1304  is pivotally coupled by pin  1306  to the distal end of arm  1302 , while the proximal end of arm  1304  is pivotally coupled to cam plate  126 . The relative lengths of the interior of casement  440  and shank  113  restrict the throw of bolt  112 , and thereby limit the angular rotation of cylinder plug  116  and cam plate  126 . 
     In operation, a key (not shown) able to demonstrate both mechanical conformance when inserted into keyway  118  and electronic conformance to the digital signature held by the key with the memory of circuit  130  (not separately shown) mounted upon circuit board  139 , will enable circuit  130  to apply an electrical current to the coil of solenoid  1202 . The electrical current retracts both armatures  1204  radially inwardly and against compression spring  1216 . This axial withdrawal of both armatures  1204  enables the manual torque applied to the key by the user, and by the key to keyway  118  in a clockwise direction, to turn lever  1302  clockwise. The clockwise rotation of lever  1302  in turn, forces arm  1304  to rotate counter-clockwise around axis N. This counter-clockwise rotation forces surface  1209  of cam nose  1208  out of the detent formed by arch  1222  and drives cam nose  1208  to the left, and thus accommodates counter-clockwise rotation of cam plate  126  against the bias force of spring  1206  (not separately shown in  FIGS. 67-69 ). While energized by circuit  130 , solenoid  1202  withdraws simultaneously armatures  1204  in opposite axial directions by a sufficient distance to allow the distal ends of armatures  1204  to extend axially outwardly by an axial length that is less the distance between opposite side walls  1212 . In a locked, unenergized state, solenoid  1202  has armatures  1204  extending to a coaxial length of somewhat less than the separation between opposite side walls  1212 . In these particular embodiments, the energization of solenoid  1202  causes the retraction of armatures  1204  into solenoid  1202  by an axial length of less than the least distance separating side walls  1212 . The retraction of armatures  1204  permits the manual rotation of cylinder plug  116  to transmit the rotational force to cam plate  126  via lever  1302  and spring  1304 . Elliptical lobe  1008  may be coaxially mounted with cam plate  126  to rotate counter-clockwise around axis N, as indicated in  FIG. 68 , when a conforming key is inserted into keyway  118  and rotated clockwise around axis N. The distally entending end  1008  of lobe  1013  rides along the transverse wall of the recess  1010  formed within shank  113 , and the concomitant camming action between the distal end  1008  of lobe  1013  and the wall of slot  1010  forces shank  113  to the right, as is indicated in  FIG. 68 , thereby forcing bolt  112  to withdraw inside casement  440 . This places the lock in an unlocked state shown by  FIG. 68 . Although various types of key retainers may be incorporated into cylinder plug  116  to hold the key (not separately shown) within keyway  118 , as long as no counter-clockwise force is applied to the key, cam nose  1208  will remain outside of, and arcuately displaced from arch  1222 , and the lock remains in its unlocked state. 
     The lock may be returned to its locked state by a manual application of a counter-clockwise torque to the key and cylinder plug  116 , that, in turn, draws lever  1302  counter-clockwise, and pulls arm  1304  counter-clockwise, thereby causing cam plate  126  to rotate clockwise until the spring-loaded nose  1208  is released by fence  1220  to move to the right and into arch  1222 . Either a previous, or a subsequent interruption of electrical current to the coil of solenoid  1202  enable armatures  1204  to move axially outwardly, in opposite directions, and to extend into the conforming slots  1210  formed in the circumferential wall of cam plate  126 . Completion of the counter-clockwise rotation of the key within keyway  118  enables the key to be withdrawn from the retainer and keyway  118 . 
     Should excessive torque be applied to cylinder plug  116  as, for example, insertion of a conforming shank (e.g., the bit of a screwdriver) into keyway  118  during an illicit attempt to improperly obtain entry into the volume that is being secured by the lock, and if the excessive torque is adequate to rotate cylinder plug  116  around axis M, the combination of the engagement of nose  1208  and arch  1222 , and the distal ends of armatures  1204  and slots  1210 , prevents arm  1304  from forcing cam  1260  to rotate around axis N. If the magnitude of the torque is increased, pin  1306  coupling lever  1302  and arm  1304  will ultimately fail, as is shown in  FIG. 69 , before arm  1304  will force cam plate  126  to rotate around axis N. 
     Moreover, if cylinder plug  116  is completely wrenched out of the cover  128  of the lock in a further effort to obtain unauthorized entry, the radial offset between axes M, N denies direct access to both cam plate  126  the resulting void created by the absence of cylinder plug  116  does not provide direct access to either cam  1260  or to cam locking bolt  1200 . Access to cylinder plug  116  is further restricted by the relative thinness of casement  440 . 
     In some embodiments, lever  1302 , pin  1306  and arm  1304  may serve as electrical conductors of signals propagating between a key and circuit board  139 . Accordingly, these components may be made of alloys that are electrically conductive at room temperatures, with pin  1306  being made of a softer electrically conducting material that will shear after being subjected to excessive torque, before the application of the excessive torque to cylinder plug  116  causes sufficient deformity of either fence  1220 , or to cam locking bolt  1200 , to allow rotation of cam plate  126  around axis N. 
       FIGS. 70 through 73D  illustrate an assembled alternative embodiments with cylinder plug  116  positioned toward the lower left interior of casement  440 , to rotate around a first axis M that is laterally offset from cam plate  126 . Cam plate  126  is positioned within casement  440  to rotate around a second axis N that is preferably parallel, and laterally offset from first axis M. Cylinder plug  116  is joined with, and simultaneously rotates around axis M with a first sector gear  1322  that bears a plurality of teeth  1324  that are meshed with corresponding teeth  1326  arcuately extending around an arc of the periphery of cam plate  126 , to form a second sector gear that rotates about axis N simultaneously with cam plate  126 . As manual rotation of a key that mechanically and electrically conforms with both keyway  118  and a current code stored within the circuit  139  borne by cam plate  1260  turns cylinder plug  116 , sector gear  1322  rotates clockwise around axis M as shown by  FIG. 71 , while meshed with teeth  1326  of the sector gear formed on cam plate  126 ; this, in turn, drives cam plate  126  around axis N. The rotation of cam plate  126  causes the edge  1008  of the elliptical lobe  1013  to cam against the inner surface of recess  1010  and force shank  113  to the right while drawing bolt  112  toward the right as shown in  FIG. 71 , and into casement  440 , thereby placing the lock in the unlocked state shown by  FIG. 71 . 
     In the embodiment shown by  FIGS. 70 and 71 , to forestall unauthorized entry, the teeth  1324  of the cylinder plug gear  1322  may be made of a softer material such as brass, while teeth  1326  along the circumference of cam plate  126  may be made of a relatively harder material such as steel. Alternatively, teeth  1322  may be made of a softer material such as teflon while teeth  1326  may be made of a relatively harder material such as brass. Application of excessive torque to cylinder plug  116  such as when a non-conforming thin, elongate object such as the shaft of a screwdriver is forced into keyway  118 , will cause the softer teeth  1322 ,  1326  to strip against the harder teeth, before cam plate  126  rotates. In some of these embodiments, the teeth  1322 ,  1326  may be used to provide one leg of an electrical path between the key and circuit board  139 ; consequently, electrically conductive materials of different relative hardness should be used for the teeth  1322 ,  1326  in order to assure that the teeth concurrently provide a continuous electrical path and strip relative to one another when excessive torque is applied to cylinder plug by a non-conforming object. The disparity in the degree of relative hardness between teeth  1322 ,  1326  is determined by the desire to have either teeth  1322  or teeth  1326  fail, and shear from the associated gear, before application of the excessive torque to cylinder plug  116  causes sufficient deformity of either fence  1220  or cam locking bolt  1200  to allow rotation of cam plate  126  around axis N. 
     Turning now to  FIGS. 72 through 73D , an alternative to the embodiments of  FIGS. 67 and 70  is shown by  FIG. 72  in a partially unassembled, unlocked state, and in  FIGS. 73 ,  73 A and  73 B, in a locked state. In this embodiment, sector gear  1322  may be electrically insulated, top and bottom, from cylinder plug  116 . Consequently, the materials of gear teeth  1322 ,  1326  do not need to be electrically conducting. An electrical contact  716  extending downwardly beyond the distal end of the blade  502  of key  500 , makes an electrical contact with a socket  1502  electrically coupled to one end of an electrically conductive contact wiper  416  that is electrically isolated by electrical insulators  1504 ,  1506  from the electrically conducting elements of cylinder plug  116 . The other end of contact wiper  416  is biased, as a leaf spring, to make continuous contact with a spring loaded electrical contact  417  such as a pogo-pin, mounted upon the circuit board  139  borne by cam plate  126 . The dashed lines presented in  FIG. 73D  trace the arms of electrical current from two electrically isolated parts of key  500 , namely blade  502  and terminal  716 . Current from the battery side of key  500  traces a path through contact  716  extending, for example, through, but insulated from, the blade  502 , through socket  1502 , spring contact wiper  416 , and spring-loaded contact pin  417  to circuit board  139 . Circuit board  139  distributes the battery voltage to the individual components of circuit  130 . A return, or local ground path may extend from a surface mount terminal on circuit board  139  that is located beneath the head of threaded fastener  1013 , through threaded fastener  1013  and an electrically conducting substrate  1508  beneath cam plate  126  and spacer  1441 , through upper pivot post  1440 , through casement cover  128 , and through cylinder plug  116  to the electrically conducting portion of the blade  502  of key  500 . Alternatively, or additionally, a return path may extend between circuit board  139 , threaded fastener  1013 , substrate  1508 , lower spacer  1431 , lower pivot  1430 , casement  440 , and through either cover  128  and cylinder plug  116  or through lower pivot  430 , lower spacer  431  and cylinder plug  116 , to the electrically conducting portion of the blade of key  502 . The flared distal end and spring loading of contact wiper  416  assures the continuity of electrical contact between the cylinder plug and circuit board  139  throughout the rotation between the locked and opened states of the mechanism. In an alternative embodiment, a flexible ribbon cable carrying two or more leads, may extend between one socket mounted upon cylinder plug  116  and a second socket mounted upon circuit board  139 . 
       FIGS. 74 and 75  illustrate a top view of an assembled alternative embodiment, respectively in unlocked and locked states. A trapezoidal shaped cam plate  126  bears an elliptical lobe  1008 . Circuit board  139  (not shown in  FIG. 75 ), and cam locking bolt  1200  bearing solenoid  1202 , are mounted upon and rotate with cam plate  126 . As better illustrated by  FIG. 74 , cam nose  1209  may be constructed with a multi-sided, or even a polygonal shape, as opposed to an arcuate shape, that generally conforms the concave shape of arch  1222 , so that when a key (not shown) providing mechanical conformance when inserted into keyway  118  and electronic conformance of the digital signature held by the key with the memory of circuit  130  (not separately shown) mounted upon circuit board  139  will enable circuit  130  to apply an electrical current to the coil of solenoid  1202 , thereby retracting both armatures  1204  against compression spring  1216 . This enables the manual torque applied by the key to keyway  118  in a clockwise direction, to cam nose  1209  of cam locking bolt  1200  out of arch  1222  and thus accommodate clockwise rotation of cam plate  126  against the bias force of spring  1206 , as shown by  FIG. 74 . While energized by circuit  130 , solenoid  1202  withdraws armatures  1204  by a sufficient distance to allow the distal ends of armatures  1204  to an axial length less the distance between opposite side walls  1212 . In a locked, unenergized state solenoid  1202  has armatures  1204  extending to a coaxial length of somewhat less than the separation between opposite side walls  1210 ; it is the energization of solenoid  1202  that retracts solenoid  1202  to an axial length less than least distance separating side walls  1212 . 
     Cylinder plug  116  and the camming surface  1008  of elliptical lobe  1013  are coaxially mounted to rotate clockwise, as indicated in  FIG. 74 , when a conforming key is inserted into keyway  118  and rotated clockwise. The distally extending end  1008   a  of lobe  1008  rides along the transverse wall  1010   a  of the recess  1010  formed within shank  113 , and the concomitant camming action between end  1008   a  and wall  1010   a  forces shank to the right to withdraw into casement  440 . As is shown in  FIG. 74 , while approaching a fully unlocked orientation, the flat side  126   a  of cam plate  126  will abut the interior side wall of casing  440  and prevent farther rotation of cylinder  116  and elliptical lobe  1008  within recess  1010  formed in shank  113 . Either alternatively, or simultaneously, and depending upon the dimensions of recess  1010 , shank  113  may engage lobe  1008  to terminate farther travel into casement  440 . A detent  126   c  may be formed to extend above the surface of shank  113  to engage an opposite flat side  126   b  of cam plate  126 , as shown by  FIG. 75 , and prevent farther counterclockwise rotation of cam plate  126 , lobe  1008  and cylinder plug  116  when the shoulders of cam plate  113  adjacent to bolt  112  abut against the left interior wall of casement  440 . 
     Turning now to  FIGS. 76 through 76D , an alternative embodiment of a cam lock is illustrated with a lever and electrical contact mounted on the exterior of cylinder plug  116 , rotating simultaneously with plug  116  while driving both arms  1482 ,  1484  of a spring that together operationally couple cylinder plug  116  with cam plate  1260 . One end of arm  1482  engages a pivot  1486  at the distal end of lever  1480  while the opposite end of the other arm  1484  may engage a second pivot  1490  that may be mounted upon and extend above cam plate  1260 . A recess  1012  in shank  113  allows bolt  112  and its accompanying shank  113  to reciprocally travel relative to casement  440  while pivot post  430  anchors cylinder plug  116  coaxially with spacer post  431  within casement  440 . 
       FIG. 76 , a top view showing the alternative embodiment is a partially unassembled state, illustrates the bolt  112  and the arms  1482 ,  1484  in their corresponding positions while the lock is in its locked state with bolt  112  shown extending to the left and beyond casement  440  while the mechanism is in its locked state. 
       FIG. 76A  is a top view of the embodiment illustrated by  FIG. 76 , while in an unlocked state; 
       FIG. 76B  is a top view of the embodiment of  FIG. 76 , shown after application of excessive torque to the keyway; 
       FIG. 76C  is an enlarged side elevational view illustrating the electrical contact system and insulating material in the embodiment illustrated by  FIG. 76 ; and 
       FIG. 76D  is an enlarged side elevational view showing the electrical and data path through the embodiment illustrated by  FIG. 76 . Electrical contact  716  extending downwardly beyond the distal end of the blade  502  of key  500 , makes an electrical contact with a socket  1502  electrically coupled to one end of an electrically conductive contact wiper  416  that is electrically isolated by electrical insulators  1504 ,  1506  from the electrically conducting elements of cylinder plug  116 . The other end of contact wiper  416  is coupled to spring  1480  that is, in turn, coupled to an electrical contact  417  mounted upon circuit board  139  and borne by cam plate  126 . The dashed lines presented in  FIG. 76D  trace the arms of electrical current from two electrically isolated parts of key  500 , namely blade  502  and terminal  716 . Current from the battery side of key  500  traces a path through contact  716  extending, for example, through, but insulated from, the blade  502 , through socket  1502 , spring contact wiper  416 , and spring-loaded contact pin  417  to circuit board  139 . Circuit board  139  distributes the battery voltage to the individual components of circuit  130 . A return, or local ground path may extend from a surface mount terminal on circuit board  139  that is located beneath the head of threaded fastener  1013 , through threaded fastener  1013  and an electrically conducting substrate  1508  beneath cam plate  126  and spacer  1441 , through upper pivot post  1440 , through casement cover  128 , and through cylinder plug  116  to the electrically conducting portion of the blade  502  of key  500 . Alternatively, or additionally, a return path may extend between circuit board  139 , threaded fastener  1013 , substrate  1508 , lower spacer  1431 , lower pivot  1430 , casement  440 , and through either cover  128  and cylinder plug  116  or through lower pivot  430 , lower spacer  431  and cylinder plug  116 , to the electrically conducting portion of the blade of key  502 . The pivoted mechanical connection between the distal end of spring loading of contact wiper  416  and the distal end of spring  1480  assures the continuity of electrical contact between the cylinder plug and circuit board  139  throughout the rotation between the locked and opened states of the mechanism. In an alternative embodiment, a flexible ribbon cable carrying two or more leads, may extend between one socket mounted upon cylinder plug  116  and a second socket mounted upon circuit board  139 . 
       FIG. 77  illustrates an alternative embodiment with the electrical contacts removed in order to clearly show the details of the mechanical components sited within casement  440 . Cylinder plug  116  is mounted within casement  440  to rotate around axis M, while cam  1260  is mounted within casement  440  to rotate around axis N. Axis N and cam  1260  are spaced radially apart from cylinder plug  116  and axis M. In this embodiment, lever  416 , in combination with a spring  1880 , operationally connects cylinder plug  116  with cam  1260 . Lever  1486  extends radially outwardly from cylinder plug  116 , and a boss  1486  mounted on the distal end of lever  416  pivotally engages a distal end of arm  1882  of spring  1880 . A coiled central length  1884  of spring  1880  joins arm  1882  to a second arm  1888 . The distal end of arm  1882  pivotally engages a boss  1262  extending axially outwardly from cam  1260 . The relative lengths of the interior of casement  440  and shank  113  restrict the throw of bolt  112 , and thereby limit the angular rotation of cylinder plug  116  and cam  1260 . Spring  1880  serves as a flexible buffer and torque limiting device between the angular rotation of cylinder plug  116  and cam  1260 . 
     In operation, when a key (not shown) able to demonstrate both mechanical conformance when inserted into keyway  118  and electronic conformance to the digital signature held by the key with the memory of circuit  130  (not separately shown) mounted upon circuit board  139  will enable circuit  130  to apply an electrical current to the coil of solenoid  1202 . The electrical current retracts both armatures  1204  radially inwardly and against compression spring  1216 . This axial withdrawal of both armatures  1204  enables the manual torque applied by to the key by the user, and by the key to keyway  118  in a clockwise direction, to turn lever  1480  clockwise and, in turn, force arm  1882  toward arm  1888 , thus forcing boss  1262  to rotate counter-clockwise around axis N. The rotation forces surface  1209  of cam nose  1208  out of the detent formed by arch  1222  and drives cam nose  1208  to the left, and thus accommodates counter-clockwise rotation of cam plate  126  against the bias force of spring  1206  (not separately shown in  FIG. 77 ). While energized by circuit  130 , solenoid  1202  withdraws armatures  1204  in opposite axial directions by a sufficient distance to allow the distal ends of armatures  1204  to extend axially outwardly by an axial length that is less the distance between opposite side walls  1212 . In a locked, unenergized state solenoid  1202  has armatures  1204  extending to a coaxial length of somewhat less than the separation between opposite side walls  1212 ; it is the energization of solenoid  1202  that retracts solenoid  1202  to an axial length less than least distance separating side walls  1212 , and permits the manual rotation of cylinder plug  116  to transmit the rotational force to cam  1260  via lever  1480  and spring  1880 . Elliptical lobe  1008  may be coaxially mounted with cam  1260  to rotate counter-clockwise around axis N, as indicated in  FIG. 77 , when a conforming key is inserted into keyway  118  and rotated clockwise. The distally entending end of lobe  1008  rides along the transverse wall of the recess  1010  formed within shank  113 , and the concomitant camming action between the distal end of lobe  1008  and the wall of slot  1010  forces shank  113  to the right, thereby withdrawing bolt  112  to withdraw inside casement  440 . This places the lock in an unlocked state. Although a key retainer holds the key (not separately shown) within key slot  118 , as long as no counter-clockwise force is applied to the key, cam nose  1208  remains outside of arch  1222 , and the lock remains in its unlocked state. The lock may be returned to its locked state by a manual application of a counter-clockwise torque to the key and cylinder plug  116 , that, in turn, draws lever  1480  counter-clockwise, and pulls arm  1882  away from coil  1884  and arm  1888 , causing cam  1260  to rotate clockwise until the spring-loaded nose  1208  is released by fence  1220  to move to the right and into arch  1222 . Either a previous, or a subsequent interruption of electrical current to the coil of solenoid  1202  enables armatures  1204  to simultaneously move axially outwardly, in opposite directions, and to extend into the conforming slots  1210  formed in the circumferential wall of cam  126 . Completion of the counter-clockwise rotation of the key enables the key to be withdrawn from the retainer and keyway  118 . 
     Should excessive torque be applied to cylinder plug  116  as, for example, an attempt to obtain unauthorized entry to the volume that is being secured by the lock, and if the excessive torque is adequate to rotate cylinder plug  116  around axis M, the combination of the engagement of nose  1209  and arch  1222 , and the distal ends of armatures  1204  and slots  1210  prevents spring  1880  from forcing cam  1260  to rotate around axis N. If cylinder plug  116  is completely wrenched out of the cover of the lock in a further effort to obtain unauthorized entry, because of the radial offset between axes M, N, the resulting void created by the absence of cylinder plug  116  does not provide direct access to either cam  1260  or to the components borne by cam  1260 . Access to cylinder plug  116  is further restricted by the relative thinness of casement  440 . 
     The electronic cam and its key may be employed as components of a system that uses a process for programming (i.e., in some instances a computer terminal), an optional key programming station, an electronic key, and the electronic cam. Generally, the foregoing paragraphs describe a lock that may be constructed with a housing bearing a hole centered upon a first axis, a bolt supported by the housing and moving transversely relative to the first axis to protrude beyond the housing to and extended position and to retract within the housing to a retracted position, a cylinder plug perforated by a keyway, having an exposed circumferential surface surrounding the keyway rotatably fitted within the hole, and rotating within the hole in response to rotational force applied by a key conformingly corresponding to the lock through an arc centered upon the first axis, a cam positioned to rotate with the cylinder plug as the key conformingly corresponding to the lock manually applies a rotational force to the cylinder plug rotates through the arc, a member eccentrically positioned relative to the axis, extending between the cam and the bolt to drive the bolt between the extended and the retracted positions as the cylinder plug through the arc, an electronic circuit containing a memory and a microprocessor, mounted upon and supported by the cam to rotate with the cam through the arc, the electronic circuit operationally responding to digital data carried by the key conformingly corresponding to the lock when the microprocessor determines that the digital data conformingly corresponds to resident data stored within the memory, a release spaced-apart from the cylinder and eccentrically positioned away from the first axis, the release being functionally activated by the electronic circuit to move between a deployed position preventing rotation of the cam relative to the housing, and a released position accommodating the rotation of the cam relative to the using.