Electronic cam assembly

A cam assembly may be constructed with lock cylinder perforated by a centrally positioned keyway, and having an exposed circumferential surface surrounding the keyway rotatably fitted within a centrally positioned keyhole of a housing, and rotated within the centrally positioned keyhole in response to rotational force applied by a key conformingly corresponding to the lock cylinder through an arc. An electronic circuit containing a memory and a microprocessor, is mounted upon and supported by the cam to rotate with the cam through the arc, operationally responds to digital data carried by the key that is in electronic conformance to data stored within the memory, by electrically energizing a release mechanism that is spaced-apart from the axis of rotation of the cylinder plug, to move from a deployed position preventing rotation of the cam relative to the housing.

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'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.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to the drawings,FIG. 1A,1B illustrate the salient features of a hypothetical, conventional parking meter lock100. A metal cam plate102formed with a circular shape perforated by a D-shaped hole104engages a D-shaped extension of a locking cylinder plug116. A conically shaped, concave depression106extends toward the cylinder plug116, to enable D-shaped hole104to engage the extension. A pair of radially opposite helically spiral slots108equally distantly radially spaced-apart from D-shaped hole104, perforate plate102to engage and direct the travel of connecting pins110, thereby alternately withdrawing and projecting bolts112in opposite reciprocation in the opposite directions indicated by arrows A. Typically, a mechanically bitted key50is inserted into keyway118that axially perforates a cylinder plug116that is coaxially fitted inside the cylindrical shell119that surrounds plug116. Shell119is 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 key50and the tumblers (not shown) within plug116create a shear line that enables the torque that is manually applied to the handle of key50to rotate plug116relative to shell119, thereby drawing pins110from a radially outwardly position shown inFIG. 1A, to a radially inward position closer to the center of cam plate102. Once bolts112have been withdrawn, the door into which lock assembly100has been fitted can be removed, or opened. Rotation of key50in the opposite direction causes extension of bolts112, thereby locking the door.

In the embodiment of the invention shown inFIG. 2, cylinder plug116is encased in a cylindrical shell120made of a non-electrically conductive material. This shell electrically insulates plug116from the metal door into which lock assembly101has been installed. An extension122of cylinder plug116passes through D-shaped hole104in cam plate housing126, and makes mechanical and electrical contact with a board mounted spring biased electrical contact pin136. Compression spring137biases pin136toward the axial dimension of cylindrical plug116, thereby assuring electrical contact between pin138and extension122as plug116rotates within shell120. Electronic cam assembly140contains a second board mounted spring biased pin138forming mechanical and continuous electrical contact with at least one of the reciprocally sliding bolts112.

Cam plate126(having a base with a shape substantially identical to the top view of cam plate102shown inFIG. 1B), and cover128are preferably made of an electrically insulating material such as a plastic. Circuit board139supports a plurality of integrated circuits142and other electrical components, as well as electrical contacts136,138. Bosses132, formed in a base of the cam plate housing126, receive threaded fasteners134extending through circuit board139, thereby securing circuit board139within cam plate housing126.

Turning toFIGS. 3 and 4, in conjunction withFIG. 2, when a key500corresponding to the security features (i.e., correctly bitted teeth, if the key is in fact bitted), is inserted into keyway118so that the blade502of the key serves as an electrical contact for transmission of data and power to contact136, while a spring loaded electrical contact504mounted on the other side of the head506of key500engages the circumferential exposed surface (often the exposed surface of a re-enforced insert)409of door408, thereby completing the electrical circuit between the electronic control circuit508of key500and electronic circuit130mounted on circuit board139via contacts136,138. Assuming correct electrical conformity established through the power and data transferred between circuits508(including the supply of power to circuit130from circuit508via key500and cylinder plug116), the logic and control components of circuit130will electrically activate solenoid release assembly400with the electrical current flowing through solenoid coil402, thereby withdrawing solenoid armature404upwardly in the drawing shown inFIG. 2, and thus removing armature404from slot108. This frees the length of slot108, thereby enabling pins110to travel along the arcuate lengths of corresponding slots108as a manual torque applied to key500rotates plug116and cam assembly140. In the normal locked position, shown inFIGS. 2 and 3, armature404obstructs one of the two slots108, thus preventing cam126from rotating and drawing bolts112inwardly. Solenoid assembly400may be mounted upon and supported by circuit board139. Cover128encases circuit139within the housing provided by the inner side of cam plate126, while pins110protrude into grooves108. Bolts112slide between guides410and the adjoining portion of door408.

Turning now toFIG. 5, an alternative embodiment is illustrated with a cam plate and housing126preferably made of an electrically insulating material, installed between a cylinder plug412and the rear wall426of the door of the item of furniture. Plug412is mounted with washer422, and is in contact with the front wall424of the door of the item of furniture, with keyway118aligned with hole425in front wall424. A pair of shear pins414extend between an extension123of cam plate126and fit into conforming apertures415in the base of cylinder plug412, thereby linking rotation of plug412with rotation of plate126. A single hole413is formed within rear wall426, in alignment with the armature404of solenoid400. In its inactive, normally inoperative state as shown inFIG. 5, armature404rests within aperture413under the bias of spring406.

A second hole433is formed in rear wall426, in substantial coaxial alignment with keyway118, to accommodate pivot post430of cam spacer post431, which serves to support cam plate126upon post430, thereby fastening the entire assembly against the rear wall426. A Truarc® ring428holds post431, together with plate126, against cam plate extension432. Drive pin434protrudes from the underside of cam plate126opposite circuit board139, and is received by a conforming aperture435within extension plate432.

Turning now toFIGS. 6 through 10in conjunction withFIG. 5, extension plate432protrudes beyond a slot436cut into the flange427extending between front wall424and rear wall426. When a hand held key conforming in shape to the interior of keyway118is fully inserted into keyway118, the blade of the key makes electrical contact with contact wiper416mounted upon circuit board139while an electrically separate contact pin spaced radially apart from the blade of the key makes electrical contact with the adjoining exposed surface of front wall424and, via electrical conduction through plug412, with contact wiper418also mounted upon circuit board139. Upon determination of electrical and logical compatibility of the key with circuit130mounted upon circuit board139, solenoid400is electrically charged to withdraw armature404from aperture413, thereby releasing cam plate126and plug412to rotate under the torque manually applied to the key, thereby enabling post430to rotate within aperture433, thus allowing drive pin434to rotate about the axis of post430and thereby drawing extension plate432in a direction of arrow B shown inFIG. 6, through slot436, thereby allowing door assembly423to be opened.

Turning now toFIG. 11A, block diagrams illustrate electronic circuit130for the cam assembly and electronic circuit508for the corresponding electronic key assembly500mechanically and electrically conforming to cylinder plug116and its electronic circuit130. Circuit508is constructed within the head506of key500or, alternatively, into a portable housing electrically coupled to key500. As shown inFIG. 11A, a replaceable battery (e.g., a 3.3 volt button battery) may be removably encased in the head506of key500, with the positive plurality coupled in common to one side of electronic signal filter526and the bitted blade502of the key. In this embodiment, blade502is mechanically cut with teeth510and channels511conforming to keyway118. Blade502is positively charged by battery437, and makes electrical contact with, and provides transmission of both power and data to circuit130via flexible contact wiper136mounted upon circuit board139, which is, in turn, coupled to input/output stage542. A local ground return between circuit130and circuit508is provided via flexible spring loaded electrical contact138making electrical contact with bolt112which, in turn, makes electrical contact with the electrically conducting door408of the container; a spring loaded pin507extending from the head506of key500rides upon and makes electrical contact with door408.

Circuit508may be constructed with a microprocessor512driven according to a programs stored in read only memory514, using data transient in random access memory516. A clock518provides synchronization to microprocessor512, while input/output stage522services as a buffer enabling microprocessor512to drive signal generator524. Circuit508is electrically powered by battery437.

When key500has been fully inserted into keyway118, blade502makes electrical contact with spring biased data and power contact136, while the radially spaced-apart spring bias contact504serves as a ground return making electrical contact with the surrounding region409of door408and, through bolt112, electrical contact138and input/output stage542. Within logic and control circuit130of the cam assembly, microprocessor530operates according to a program stored within read only memory534using data written into and read from random access memory536. Counter538is coupled to microprocessor530. Communication between the logic circuit130and contacts136,138are conducted through input/output stage542. A switch544is driven by input/output stage542under control of microprocessor530upon a determination by microprocessor530that key500holds a digital signature that electronically conforms to data stored within the circuit borne by circuit board139, to provide electrical current through solenoid coil402and thereby retract armature404or, alternatively, if the solenoid is constructed as a stepping motor, to energize coil402and thereby rotate armature404. The circuit illustrated inFIG. 11Ais particularly suitable for retrofitting secured containers such as existing stand-alone, municipal curbside parking meters.

Turning now toFIG. 11B, key assembly500has a blade502without bits or channels, bearing a centrally positioned electrical data and power contact716coupled to the positive polarity of battery437. Contact716is electrically insulated from the exterior surface of blade502. Blade502serves as the negative ground return via electrical contact418while contact716, serves as the power and data connector when fully inserted into keyway118, to make electrical contact with flexible spring contact416. Flexible, spring type electrical contact wipers416,418may be surface mounted upon circuit board139, in positions to make electrical contact respectively with contact716via keyway118and the electrically conducting cylinder plug412. Solenoid winding402is either surface mounted on, or supported by, circuit board139.

As illustrated byFIG. 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 board139to provide a constant voltage to circuit components such as microprocessor530, memories534,546, counter538, and input/output stage542, and to provide a source of electrical power for energizing coil402of the solenoid via switch544. In this configuration the cylinder plug is not required to serve as a ground electrical path for the connection between the key and lock circuit139. Use of an earth ground would be incidental. Leads416,418are plated copper conductors formed on the circuit board139, with lead418serving as a local ground terminal. On key circuit508, pin terminal502A serves as a ground conductor; terminal502A may be a spring loaded pin or a flexible connection, positioned to make electrical contact with lead418when the blade, or shank502, of key500is conformingly inserted into the aperture of keyway118. A spring loaded ball bearing may be inserted within keyway118to mate with a corresponding dimple in shank502, and serve as a key retainer when key500rotates keyway118out of its rest position. Terminal502A may be connected without electrical insulation to shank502, thereby connecting circuit508via shank502. Pin terminal716serves that same function as shown in the embodiment illustrated byFIG. 11B, and is electrically insulated from shank502in order to conduct data signals and provide a positive potential to circuit139via lead416.

FIG. 11Dillustrates an alternative embodiment with the cylinder plug412serving as an electrical ground path for electrical connection between key circuit508and lock circuit139. Lead416is a copper lead plated upon circuit board139, and is directly accessed by terminal716via keyway118to electrically conduct, for example, a positive potential and data signals. The key blade, or shank502serves as the ground terminal for key circuit508. Terminal716is electrically insulated by shank502serves to electrically conduct a position potential and data signals in the same function as in the embodiment illustrated byFIG. 11B.

FIG. 11Eillustrates an alternative embodiment bearing a keypad520that is exposed to manual activation by a user. A drive spindle502′, rather than a key blade, is used to apply torque to the electronic cam that bears and encases circuit139. Once the drive spindle502′ has been electrically connected with the electronic cam circuit139via keyway118′, the spindle502′ may be left within keyway118′ and removed only for service and such maintenance as replacement of battery437. Accordingly, with the exception of replacement of battery437, lock circuit139would be continuously powered by battery437borne by key circuit508. In this embodiment, lock circuit139could be equipped with merely a clock528, while key circuit508contains a counter538. As illustrated byFIG. 11F, drive spindle502′ may be constructed with an engagement keyslot502bextending either partially, or wholly, the length of shank502′, to engage a corresponding detent within keyway118. Spindle502′ may itself serve as an electrical conductor such as the ground return, that engages electrical lead418of lock circuit139, while a second electrical conductor716bextends the length of spindle502′ and is electrically insulated from the body of spindle502′ by insulation716c. Conductor716bmay be constructed as either a circuit board with a tin, copper or gold plated trace, or an electrically conducting trace itself deposited directly upon insulation716c. Conductor716bcould 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 plug412bearing apertures415, is positioned to receive within the apertures415, corresponding shear lock pins414extending outwardly from cover128for the housing formed by cam plate126. The solenoid release assembly400is mounted on circuit board139, and circuit board139is in turn inserted within the circumferential walls131of cam plate126, with surface mounted flexible spring electrical contact416centrally positioned to extend through cam plate extension123and into the vacant portion of keyway118in order to make electrical contact with the power and data conductor of the corresponding key. Contact416is surrounded by an electrical insulator420to prevent contact116from making electrical contact with either extension123or with electrically conducting plug412. Cam spacing post431and pivot post430are concentrically positioned and coaxially aligned with keyway118, to protrude from plate126toward the bolt (not shown inFIG. 12), while drive pin434extends 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 step550ofFIG. 13. Power is supplied from battery437via contact136to cam circuit130, and data is written via contact136into memory536. A comparison is then made by microprocessor530and if the data carried by the key is not electronically conforming to data held by circuit130, in step550circuit130ignores the presence of the key. Alternatively, if the key is found by circuit130in step554to be electronically conforming, in step558circuit130applies power to switch544and solenoid (or motor)400to release cylinder116to the rotational torque manually applied by the key to the lock, thus enabling in step560rotation of the cylinder in response to the manual torque, and thereby resulting in opening of the lock in step562.

InFIG. 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 housing438serving as the rear wall, attached to flange427via threaded fasteners439. This allows for a modular improvement using an embodiment of the present invention as a separate item installed within the furniture.

Turning now toFIG. 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 aperture433in the rear wall of housing440for a lock, accommodates insertion and operational rotation of pivot post430. The shank113of bolt112lies upon the inside surface of housing440. Aperture608in shank113accommodates spacer431while aperture606accommodates drive pin434to force shank113to slide against the interior surface of housing440.

Looking now toFIGS. 15,16and17in combination, insertion of an electrically conforming key into keyway118will, after electrical exchange of data via power and data conductor416, enable circuit130mounted upon circuit board139to energize the coil of solenoid400and withdraw armature404against the force of return compression spring406, thereby enabling torque manually applied by the key to cylinder plug116to rotate cam plate extension123and in turn, cam plate126; as cam plate126rotates about pivot430, drive pin434engages the surface of slot606formed in shank113, and as the clockwise rotation of the torque applied to cam plate126drives drive pin434through a clockwise arc, drive pin434travels through slot606while forcing shank113to the right inFIG. 17, thereby retracting bolt112. Subsequent counterclockwise rotation of the key to the position shown inFIG. 17, enables spring406to force armature404back into slot413after termination of the electrical current through the coil of solenoid400. Cover442may be attached to housing440by threaded fasteners439.

ConsideringFIGS. 15 through 23collectively, the assembled housing440with cover442and protruding flanges446exposed on opposite sides of housing440, may be received within channel454to enable set screws452, or other detents, to be inserted within set screw detents448. Once channel454is securely attached to the thin safety deposit door456with D-shaped key hole458aligned substantially coaxially with plug clearance hole460as shown in the assembled view ofFIG. 20B, cylinder plug116will be substantially coaxially aligned with plug clearance hole460and D-shaped key hole458of channel454and door456, respectively. As shown in the elevation view ofFIG. 22, this enables bolt112to protrude substantially beyond the left side of the door while in the locked position. Consequently, the entire lock assembly140as well as the pins462for door456, are concealed, with only board mounted data and power electrical contact416visible through keyway118, as is more apparent fromFIG. 23.

Turning now toFIGS. 24 through 27, an alternative embodiment constructed with a pair of electrically conductive attachments610, one of which is mounted upon circuit board139and one of which is mounted upon unlocking detent622, terminate opposite ends of the length of relatively thin wire made of a paramagnetic alloy of a shape-memory alloy such as a NiTiNol wire614. The locking device600is constructed with a cover442having a pair of spaced-apart, oppositely facing arcuate guide walls602partially surrounding circumferential wall131of cam plate126to form a shell. A groove613formed into one of the guide walls602conforms to the shape of spherical ball604over an arcuate length of less than one half of the circumference of ball604. Ball604is positioned principally upon cam plate126and spaced equally distantly between a pair of rectangular guides605, to extend through a gap in circumferential wall131. An unlocking detent622is held in position by an electrically conductive compression spring616, between guides605on one side, and guide wall624on its other side. Plate620also contains a circular concave groove622circumferentially conforming to the exterior of ball604with a greatest depth of less than one half the diameter of ball604. A proximal end of locking plate622is attached to conductive attachment610.

In operation, a manual key electronically conforming to circuit130after insertion into keyway118and making electrical contact with conductives416,418, enables circuit130to apply electrical current between attachment610; the electrical current causes the NiTiNol alloy wire614to contract, thereby drawing locking plate622upwardly against the force of compression spring616, as shown inFIG. 25, thereby enabling the manual torque applied by the key to cam plate126to force ball604to roll out of groove613and to roll into groove622in a direction shown by arrow B as cam plate turns clockwise in a direction indicated by arrow C. The clockwise movement of cam plate126causes drive pin434to travel along slot606, thereby forcing shank113to the right in a direction of arrow D as shown inFIG. 25, thus retracting bolt112substantially into the interior of housing440. Cam rotation and withdrawal of the key from keyway118terminates access, by causing interruption of electrical current through NiTiNol alloy wire614. Referring again toFIGS. 11A,11B, software stored in ROM534may instruct microprocessor530after a certain number of pulses from counter538to change switch544to its rest state, causing interruption of power through NiTiNol alloy wire614. This enables spring616to force locking plate620downwardly to discharge ball604alternately into groove613of guide wall602. Simultaneously, the cam clockwise rotation opposite to the direction shown by arrow C inFIG. 25, forces drive pin434against the wall of slots606, thereby causing shank113to travel in the opposite direction shown by arrow D, thus ejecting bolt112and locking the door to which the assembly has been attached.

FIG. 27Bshows a bitted cylinder700fitted with a cylinder plug704which may be incorporated into the embodiment represented byFIGS. 24 through 27A. In this embodiment, the key (not shown) can be configured with a plurality of teeth cut to conform to the shear lines707formed by the relative length of bottom pins706and top pins708within cylindrical shell702. As shown inFIG. 27B, compression spring710holds bottom pins706and top pins708inwardly to prevent rotation of cylinder704relative to shell702. A Truarc® ring428holds cylinder700within cover442. With this alternative embodiment, the key must both mechanically conform to the shear line established by pins706and708and electronically conform to the digital signature required by circuit130before access can be obtained. As shown inFIG. 28, a fixed pin712holds the extreme wall of shell712fixed into position relative to circumferential wall131that forms a cylinder housed within and rotatable within the shell formed by guide walls602.

Turning collectively toFIGS. 24 through 36, a sphere630of an electrically conductive material (preferably, with a polished exterior surface such as a chrome plated ball bearing, may be inserted into spacer123within a spherically conforming recess, under electrical contact416between the open portion of keyway118, namely632, and circuit board139. Sphere630has unrestrained multiple degrees of freedom of rotation. Consequently, sphere630blocks direct access to circuit board139and, among other advantages, deters efforts to defeat locking device600by drilling for example with a rotating bit inserted into keyway118. Accordingly, and as may be seen inFIGS. 29 and 30, electrically insulated central electrical contact716of key500makes electrical contact with contact416directly, and sphere630is interposed between contact416and an extension of keyway118through spacer123, to protect circuit board139from damage caused by improper access such as drilling through keyway118.

Turning again toFIGS. 29 and 30, when bitted key500is coaxially inserted into keyway118of a bitted cylinder plug116, the bitting of key500radially displaces top and bottom pins within shell702, 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 circuit508of the key and circuit130formed on circuit board139will enable the battery437held by the head506of key500to apply electrical power via spring pin key data contact716and contact wiper416to paramagnetic alloy wire416extending between connectors610, thereby contracting wire416and drawing locking plate620upwardly to receive a less than hemispheric exterior surface of ball604, thereby allowing cam plate126to rotate under the torque applied by the key500relative to guide wall602. Formation of groove613,620with depths of less than one radius of bearing604, in preferably less than one half of the radius of bearing604, enables the torque applied manually to key500to force bearing604out of the corresponding groove613or unlocking detent622once plate620has been positioned by either spring616or paramagnetic wire614.

Turning now toFIGS. 31 through 33, not infrequently heat is applied to the keyway118in 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 lever720is superimposed alongside locking plate620, with a pivot728rotatably attaching lever720to the upper surface of guide wall624. Re-lock lever720has a bell crank shape with one arm attached to a second paramagnetic alloy wire724extending between fasteners726,727. Application of heat to the cam assembly via keyway118will cause wire724to contract, thereby pulling the proximal end of lever720downwardly as shown inFIG. 32, thus forcing the distal end of lever720to engage slot722formed within locking plate620. This prevents plate620from moving in response to contraction of wire614due to either application of an electrical current or heat. Consequently, improper efforts to open the locking mechanism via application of heat through keyway118are thwarted because locking plate620remains under the influence of spring616, thereby preventing bearings604from leaving slot613within guide wall602.

Turning now toFIGS. 34 through 36, the cam assembly800fitted with an electrically operated motor incorporated into the locking mechanism is illustrated. The motor is constructed with a shaft808supporting a drum802bearing a slot804formed through its upper surface that is sufficiently wide to accommodate passage of the arcuately curved fence812protruding downwardly from the under side of cover422. Mechanical and electronic conformity of a key inserted into keyway118will enable circuit130to apply an electrical current to the coil814of the stepping motor, thereby turning the armature816of the motor by ninety degrees to an unlocked state accommodating passage of fence812as shown inFIG. 36as cam plate126rotates. Shaft808can rest in the motor housing810, which is in turn mounted upon circuit board139or, alternatively, directly upon cam plate126. As shown inFIG. 34, drum802contains a false notch (shown on one side)806designed to accommodate entry, but not passage of a short portion of fence812. 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 keyway118. Counterclockwise rotation and removal of the key will trigger application of a charge held by a capacitor within circuit130that has been charged by battery437, to rotate locking drum802by one additional ninety degree step in the clockwise direction to block rotation of cam plate126relative to fence812. Alternatively, the motor may be fitted with a torsion spring (not shown) anchored to the drum802and motor body810to restore the drum to its original locked position.

As shown inFIG. 35B, a bitted cylinder plug700may be incorporated into the cam assembly ofFIGS. 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 toFIGS. 37 through 41collectively, a non-bitted cylinder plug116is mounted to a cam assembly extension123via shear pins414received within conforming apertures415in a cylinder plug. A solenoid400is mounted directly upon circuit board139, as an interval component of circuit130, and is received within cavity405of cam plate126′. Lock housing440′ has one wall perforated by an opening441conforming in size and shape to solenoid armature404. In the lock state therefore, spring406holds armature404within aperture441. Correct mechanical conformance and electronic conformance between the key inserted into keyway118and circuit130will enable application of an electrical current to solenoid400that will cause withdrawal of armature404from aperture414, thereby enabling cam plate to rotate clockwise (as shown inFIG. 40) under the torque applied by the key to keyway118, thus withdrawing shank113under the force of drive pin434applied to slot606, and thus withdrawing bolt112. Clockwise rotation of the key will restore alignment between armature404and aperture441.

Turning now toFIGS. 42 through 45, an alternative embodiment is constructed with solenoid release assembly400mounted upon circuit board139, to protrude through slot901formed in cover128. A lever903pivotally attached at a distal end to cam plate126′ via a rotating pin906. Armature404is connected, at its distal end, via pin904to lever903. Pin904slides within a slot908extending nearly longitudinally along a distal portion of lever903. The distal end of lever903is terminated by a detent902conforming to aperture441. Accordingly, when spring406forces armature404to its fully extended position as shown inFIG. 44, lever903forces detent902fully within aperture441, thereby preventing rotation of cam plate126′ relative to shank113. Consequently, efforts to apply a manual torque to via keyway118to cam plate126′ will, absent electronic conformance of the circuit held by the key with circuit130mounted on cam plate126′, will cause detent902to round the circumferential surface of aperture441, thus preventing rotation of cam plate126′. Given electronic conformance between circuit held by the key and circuit130however, electrical current running through solenoid400will retract armature404within solenoid400against spring406, thereby compressing spring406while withdrawing detent902from aperture441, thus enabling clockwise rotation of cam plate126′ relative to shank113and housing440′. This rotation causes drive pin434to engage the walls of slot606and force shank113along the walls of spacer431. Consequently, slots608slides along the circumferential walls of spacer431, thus withdrawing bolt112substantially into the interior of housing440′. Cover442fits upon and may be fastened with threaded fasteners to housing440′.

It may be noted that this structure provides an indirect locking mechanism with detent902. Moreover, the radial displacement of detent902from the central axis of keyway118provides an enhanced advantage in the amount of torque required to mechanically defeat the lock. Additionally, the increased diameter of pin906pivotally coupling the distal end of lever903to the peripheral of cam plate126′ further enhances a mechanical strength of locking mechanism.

Turning now toFIGS. 46 through 49, an alternative embodiment is constructed using a solenoid400mounted upon cam plate126. Solenoid400drives a locking plate1006reciprocally between a pair of radial extensions1031of circumferential wall131which forms a cylinder housed within and rotatable with respect to the shell, against the force of compression spring406. Spring406is mounted between the cap405terminating one end of locking end1006, and the side of upper extension wall1031. Locking plate1006is partially perforated by blind false notch806positioned to be axially aligned with and to receive the distal end of shaft1007of plunger1002when solenoid400is un energized and in its rest position as shown inFIG. 48. When a mechanically conforming key is inserted into keyway118and the digital electronic signature borne by that key conforms to data stored within circuit130, solenoid400is energized to retract plate1006in a downward direction, as shown inFIG. 48, and unlocking slot804is axially aligned with the distal end of shaft1007, as shown inFIG. 49.

Guide plate1004extends transversely between radial extension walls1031, and is perforated by a through aperture accommodating entry in partial passage of the enlarged proximal end of shaft1007. Return spring407acts against plate1004to hold plunger1002within groove413formed in guide wall602. The distal doubled end surfaces1003of plunger1002conform with the shape of groove413to form an obtuse angle at its apex, thereby enabling application of manual torque to keyway118to force, through camming action between surfaces1003and the walls of groove413, plunger1002to the left as shown inFIG. 48. Consequently, absent electronic conformance between the digital electronic signature held by the key inserted in the keyway118and data stored within the memory of circuit130, the distal end of shaft1007will engage false notch806. This is frequently the situation when a person seeking unauthorized access to the container secured by the locking mechanism attempts to simultaneously jar solenoid400while overcoming the bias force created by spring force406. The much larger force created by return spring407however requires a substantial jarring motion applied to the container, with result that the plunger1002tends to move suddenly and thereby overcome the bias force of return spring407, with result that the distal end of shaft1007engages false notch806. Electronic conformance between the signature held by the key and data stored within the memory of circuit130enables radially inward movement of shaft1007through aperture804, thereby enabling the manual torque to rotate cam plate126clockwise as shown inFIG. 49. The apex of surfaces1003rides along the inner circumferential surface of guide wall602.

Turning now toFIGS. 50 through 53, an alternative embodiment is shown constructed with an elliptical bolt drive lobe1008positioned between post430and cam plate126. This embodiment eliminates the need for a separate, discrete bolt drive pin434. Instead, the configuration shown relies upon camming action between surface1011of lobe1013to rotate through ninety degrees while engaging retract surface1012as manual torque is applied to a key that mechanically and electrically conforms to keyway118and circuit130, as the key is turned counterclockwise (looking atFIGS. 52 and 53). This enables the camming action between surfaces1011,1012to draw shank113to the right (as shown inFIGS. 52 and 53), thereby withdrawing bolt112substantially within housing440. In an alternative configuration, the bitted plug704may be substituted for cylinder plug116, to add an additional element of access security.

Turning now toFIGS. 54 through 57show yet another alternative embodiment constructed with a cam plate126″ having a centrally positioned spacer431and pivot post430coaxially aligned with the keyway118of cylinder plug116mounted upon cover128via spacer123. Cam plate126″ is equipped with a downwardly depending drive pin434radially offset from the central axis of keyway118. A notch1113is formed at an intersection of two sides of plate126″ separated by spacer431from bolt112. Notch1113engages blocking plate1107mounted on the distal end of armature404. Solenoid400is mounted upon the floor of housing440, rather than upon cam plate126″. A pair of electrical leads1018coupled to plug1012electrically engage a pair of jacks1016mounted upon circuit board139. Leads1018flex as cam plate126″ rotates through an approximate forty five degree arc in response to manual torque applied by a key inserted into keyway118when the key mechanically and electronically conforms to keyway118and circuit130.

Mechanical conformance of the key to keyway118and electronic conformance of the electronic digital signature held by the key to digital data stored within circuit130enables circuit130to apply an electrical current derived from the battery held by the key (or alternatively, by a battery mounted within circuit130) to the winding of solenoid400via leads1018, thereby retracting armature404and locking plate1101, and thus allowing counterclockwise rotation of cam plate126″ under the force of the torque of the key. This causes drive pin434to force the walls of slot606to the right as shown inFIG. 54, thereby shifting shank113and bolt112to the right, thus withdrawing bolt112substantially within housing440. Cover442is secured to housing446. As shown inFIG. 57, plug1020may be easily removed from jacks1016to enable and easy replacement of solenoid400.

Turning now toFIGS. 58 through 65, an alternative embodiment of a cam assembly is illustrated with a cam plate126′″ supporting the circuit board139containing an electronic circuit such as130(FIG. 11B). Power and data electrical contact wiper416is centrally positioned across the longitudinal axis (which extends out of the plane of the paper) while ground contact wiper418is spaced regularly apart from contact wiper416. Shear pins414may connect a cylinder plug116with a centrally disposed boss1218formed within cam plate126′″. An elliptical bolt drive lobe1008extends axially downwardly from the lower surface of cam plate126′″, to support a much smaller pivot post430that is symmetrically positioned around the longitudinal axis F of keyway118. Elliptical lobe1008is situated within slot1010centrally formed within shank113. The central boss1218of cam plate126′″ has a series of spaced-apart side walls1210,1212and1214connected by an inwall1215, loosely accommodating a cam locking bolt1200, while allowing cam locking bolt1200to reciprocate radially relative to central axis F. A spring1206is compressed between end wall1215and the central inside portion of cam locking bolt1200, thereby holding nose1208of cam locking bolt1200outwardly protruding to engage an arch1222formed in a guide wall1220of housing cover1240.

Solenoid1202blocks cam locking bolt1200with oppositely extending coaxially positioned armatures1204which, when solenoid1202is de-energized, extend axially outwardly as shown inFIG. 60in order to place the cam assembly in the locked position. Solenoid1202may be constructed with a single annular wound coil driving both armatures1204in opposite coaxial directions. Mechanical conformance of the key inserted into keyway118and electronic conformance of the digital signature held by the key with the memory of circuit130(not separately shown) mounted upon circuit board139will enable circuit130to apply an electrical current to the coil of solenoid1202, thereby retracting both armatures1204against compression spring1216. This enables the manual torque applied by the key to keyway118in a clockwise direction, to cam nose1208of cam locking bolt1200out of arch1222and thus accommodate clockwise rotation of cam plate126′″ against the bias force of spring1206, as shown byFIG. 63.

While energized by circuit130, solenoid1202withdraws armatures1204by a sufficient distance to allow the distal ends of armatures1204to an axial length less the distance between opposite side walls1212. In a locked, unenergized state solenoid1202has armatures1204extending to coaxial length somewhat less than the separation between opposite side walls1210; it is the energization of solenoid1202that retracts solenoid1202to an axial length less than least distance separating side walls1212. In one embodiment, each armature1204extended approximately 0.130 inches while solenoid1202was de-energized, but extended only 0.050 inches while solenoid1202was energized. Wire leads1228electrically coupled the coil of solenoid1202to circuit130. It may be seen therefore, that counterclockwise rotation of the key placed within keyway118will enable nose1208of cam locking bolt1200to reciprocate regularly outwardly into arch1222prior to withdrawal of the key.

In an embodiment illustrated byFIG. 66, an alternative to the construction of the embodiment ofFIGS. 58 through 65is shown with a pair of compressible springs1206abeing substituted for the single compressible spring1206. Each spring1206ais seated within a different recess1210to bias a boss1208aof cam nose1208toward engagement against guide wall1220; the rotary force of manual rotation of a conforming key within keyway118overcomes the combined bias forces of springs1206a, and enables reciprocal displacement of cam nose1208from engagement within arch1222and, ultimately, movement of shank113and the concomitant withdrawal of bolt112toward the interior of casement440.

FIGS. 67 through 69illustrate an assembled alternative embodiment of the principles of the present invention with an articulated lever1300operationally coupling cylinder plug116with cam plate1260while the shank113of bolt112is held by drive lobe1008mounted on cam plate126in a locked state, extending outwardly beyond the adjacent wall of casement440for the lock. Cylinder plug116is positioned toward the lower left interior of casement440, to rotate around a first axis M that is laterally offset from cam plate126. Cam plate126, which may, in a particular embodiment, be the same assembly as cam plate126′″ illustrated inFIG. 66, albeit without spacer123and with cylinder plug116being separately and independently mounted along axis M, is positioned within casement440to 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. 73,73A through73D,76C and76D, circuit board139is mounted upon, and borne by, cam plate126. Circuit board139carries the individual components of circuit130and, optionally, a battery. An electrical contact is formed on circuit board139beneath the head of threaded fastener1013, and an electrically conducting substrate1508lies beneath cam plate126. Cam plate126is pivotably mounted between lower spacer1431and upper spacer1441. Spacers1431,1441are respectively supported by lower pivot post1430and upper pivot post1440, that are rotatably seated within recesses formed, respectively, within the base of casement440and cover128.

FIG. 68shows a top view of the embodiment ofFIG. 67, while in an unlocked state with bolt112drawn by clockwise rotation of lobe1008against recess1010within shank113, into the interior of casement128. In this embodiment, lever1302, in combination with arm1304, operationally connects cylinder plug116with cam plate1260. Lever1302is joined, preferably in a non-rotating relation, to and extends radially outwardly from, cylinder plug116. Alternatively, lever1302may be pivotally coupled to cylinder plug116to experience a limited degree of lost motion prior to following any rotation experienced by cylinder plug116. The distal end of arm1304is pivotally coupled by pin1306to the distal end of arm1302, while the proximal end of arm1304is pivotally coupled to cam plate126. The relative lengths of the interior of casement440and shank113restrict the throw of bolt112, and thereby limit the angular rotation of cylinder plug116and cam plate126.

In operation, a key (not shown) able to demonstrate both mechanical conformance when inserted into keyway118and electronic conformance to the digital signature held by the key with the memory of circuit130(not separately shown) mounted upon circuit board139, will enable circuit130to apply an electrical current to the coil of solenoid1202. The electrical current retracts both armatures1204radially inwardly and against compression spring1216. This axial withdrawal of both armatures1204enables the manual torque applied to the key by the user, and by the key to keyway118in a clockwise direction, to turn lever1302clockwise. The clockwise rotation of lever1302in turn, forces arm1304to rotate counter-clockwise around axis N. This counter-clockwise rotation forces surface1209of cam nose1208out of the detent formed by arch1222and drives cam nose1208to the left, and thus accommodates counter-clockwise rotation of cam plate126against the bias force of spring1206(not separately shown inFIGS. 67-69). While energized by circuit130, solenoid1202withdraws simultaneously armatures1204in opposite axial directions by a sufficient distance to allow the distal ends of armatures1204to extend axially outwardly by an axial length that is less the distance between opposite side walls1212. In a locked, unenergized state, solenoid1202has armatures1204extending to a coaxial length of somewhat less than the separation between opposite side walls1212. In these particular embodiments, the energization of solenoid1202causes the retraction of armatures1204into solenoid1202by an axial length of less than the least distance separating side walls1212. The retraction of armatures1204permits the manual rotation of cylinder plug116to transmit the rotational force to cam plate126via lever1302and spring1304. Elliptical lobe1008may be coaxially mounted with cam plate126to rotate counter-clockwise around axis N, as indicated inFIG. 68, when a conforming key is inserted into keyway118and rotated clockwise around axis N. The distally entending end1008of lobe1013rides along the transverse wall of the recess1010formed within shank113, and the concomitant camming action between the distal end1008of lobe1013and the wall of slot1010forces shank113to the right, as is indicated inFIG. 68, thereby forcing bolt112to withdraw inside casement440. This places the lock in an unlocked state shown byFIG. 68. Although various types of key retainers may be incorporated into cylinder plug116to hold the key (not separately shown) within keyway118, as long as no counter-clockwise force is applied to the key, cam nose1208will remain outside of, and arcuately displaced from arch1222, 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 plug116, that, in turn, draws lever1302counter-clockwise, and pulls arm1304counter-clockwise, thereby causing cam plate126to rotate clockwise until the spring-loaded nose1208is released by fence1220to move to the right and into arch1222. Either a previous, or a subsequent interruption of electrical current to the coil of solenoid1202enable armatures1204to move axially outwardly, in opposite directions, and to extend into the conforming slots1210formed in the circumferential wall of cam plate126. Completion of the counter-clockwise rotation of the key within keyway118enables the key to be withdrawn from the retainer and keyway118.

Should excessive torque be applied to cylinder plug116as, for example, insertion of a conforming shank (e.g., the bit of a screwdriver) into keyway118during 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 plug116around axis M, the combination of the engagement of nose1208and arch1222, and the distal ends of armatures1204and slots1210, prevents arm1304from forcing cam1260to rotate around axis N. If the magnitude of the torque is increased, pin1306coupling lever1302and arm1304will ultimately fail, as is shown inFIG. 69, before arm1304will force cam plate126to rotate around axis N.

Moreover, if cylinder plug116is completely wrenched out of the cover128of the lock in a further effort to obtain unauthorized entry, the radial offset between axes M, N denies direct access to both cam plate126the resulting void created by the absence of cylinder plug116does not provide direct access to either cam1260or to cam locking bolt1200. Access to cylinder plug116is further restricted by the relative thinness of casement440.

In some embodiments, lever1302, pin1306and arm1304may serve as electrical conductors of signals propagating between a key and circuit board139. Accordingly, these components may be made of alloys that are electrically conductive at room temperatures, with pin1306being 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 plug116causes sufficient deformity of either fence1220, or to cam locking bolt1200, to allow rotation of cam plate126around axis N.

FIGS. 70 through 73Dillustrate an assembled alternative embodiments with cylinder plug116positioned toward the lower left interior of casement440, to rotate around a first axis M that is laterally offset from cam plate126. Cam plate126is positioned within casement440to rotate around a second axis N that is preferably parallel, and laterally offset from first axis M. Cylinder plug116is joined with, and simultaneously rotates around axis M with a first sector gear1322that bears a plurality of teeth1324that are meshed with corresponding teeth1326arcuately extending around an arc of the periphery of cam plate126, to form a second sector gear that rotates about axis N simultaneously with cam plate126. As manual rotation of a key that mechanically and electrically conforms with both keyway118and a current code stored within the circuit139borne by cam plate1260turns cylinder plug116, sector gear1322rotates clockwise around axis M as shown byFIG. 71, while meshed with teeth1326of the sector gear formed on cam plate126; this, in turn, drives cam plate126around axis N. The rotation of cam plate126causes the edge1008of the elliptical lobe1013to cam against the inner surface of recess1010and force shank113to the right while drawing bolt112toward the right as shown inFIG. 71, and into casement440, thereby placing the lock in the unlocked state shown byFIG. 71.

In the embodiment shown byFIGS. 70 and 71, to forestall unauthorized entry, the teeth1324of the cylinder plug gear1322may be made of a softer material such as brass, while teeth1326along the circumference of cam plate126may be made of a relatively harder material such as steel. Alternatively, teeth1322may be made of a softer material such as teflon while teeth1326may be made of a relatively harder material such as brass. Application of excessive torque to cylinder plug116such as when a non-conforming thin, elongate object such as the shaft of a screwdriver is forced into keyway118, will cause the softer teeth1322,1326to strip against the harder teeth, before cam plate126rotates. In some of these embodiments, the teeth1322,1326may be used to provide one leg of an electrical path between the key and circuit board139; consequently, electrically conductive materials of different relative hardness should be used for the teeth1322,1326in 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 teeth1322,1326is determined by the desire to have either teeth1322or teeth1326fail, and shear from the associated gear, before application of the excessive torque to cylinder plug116causes sufficient deformity of either fence1220or cam locking bolt1200to allow rotation of cam plate126around axis N.

Turning now toFIGS. 72 through 73D, an alternative to the embodiments ofFIGS. 67 and 70is shown byFIG. 72in a partially unassembled, unlocked state, and inFIGS. 73,73A and73B, in a locked state. In this embodiment, sector gear1322may be electrically insulated, top and bottom, from cylinder plug116. Consequently, the materials of gear teeth1322,1326do not need to be electrically conducting. An electrical contact716extending downwardly beyond the distal end of the blade502of key500, makes an electrical contact with a socket1502electrically coupled to one end of an electrically conductive contact wiper416that is electrically isolated by electrical insulators1504,1506from the electrically conducting elements of cylinder plug116. The other end of contact wiper416is biased, as a leaf spring, to make continuous contact with a spring loaded electrical contact417such as a pogo-pin, mounted upon the circuit board139borne by cam plate126. The dashed lines presented inFIG. 73Dtrace the arms of electrical current from two electrically isolated parts of key500, namely blade502and terminal716. Current from the battery side of key500traces a path through contact716extending, for example, through, but insulated from, the blade502, through socket1502, spring contact wiper416, and spring-loaded contact pin417to circuit board139. Circuit board139distributes the battery voltage to the individual components of circuit130. A return, or local ground path may extend from a surface mount terminal on circuit board139that is located beneath the head of threaded fastener1013, through threaded fastener1013and an electrically conducting substrate1508beneath cam plate126and spacer1441, through upper pivot post1440, through casement cover128, and through cylinder plug116to the electrically conducting portion of the blade502of key500. Alternatively, or additionally, a return path may extend between circuit board139, threaded fastener1013, substrate1508, lower spacer1431, lower pivot1430, casement440, and through either cover128and cylinder plug116or through lower pivot430, lower spacer431and cylinder plug116, to the electrically conducting portion of the blade of key502. The flared distal end and spring loading of contact wiper416assures the continuity of electrical contact between the cylinder plug and circuit board139throughout 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 plug116and a second socket mounted upon circuit board139.

FIGS. 74 and 75illustrate a top view of an assembled alternative embodiment, respectively in unlocked and locked states. A trapezoidal shaped cam plate126bears an elliptical lobe1008. Circuit board139(not shown inFIG. 75), and cam locking bolt1200bearing solenoid1202, are mounted upon and rotate with cam plate126. As better illustrated byFIG. 74, cam nose1209may be constructed with a multi-sided, or even a polygonal shape, as opposed to an arcuate shape, that generally conforms the concave shape of arch1222, so that when a key (not shown) providing mechanical conformance when inserted into keyway118and electronic conformance of the digital signature held by the key with the memory of circuit130(not separately shown) mounted upon circuit board139will enable circuit130to apply an electrical current to the coil of solenoid1202, thereby retracting both armatures1204against compression spring1216. This enables the manual torque applied by the key to keyway118in a clockwise direction, to cam nose1209of cam locking bolt1200out of arch1222and thus accommodate clockwise rotation of cam plate126against the bias force of spring1206, as shown byFIG. 74. While energized by circuit130, solenoid1202withdraws armatures1204by a sufficient distance to allow the distal ends of armatures1204to an axial length less the distance between opposite side walls1212. In a locked, unenergized state solenoid1202has armatures1204extending to a coaxial length of somewhat less than the separation between opposite side walls1210; it is the energization of solenoid1202that retracts solenoid1202to an axial length less than least distance separating side walls1212.

Cylinder plug116and the camming surface1008of elliptical lobe1013are coaxially mounted to rotate clockwise, as indicated inFIG. 74, when a conforming key is inserted into keyway118and rotated clockwise. The distally extending end1008aof lobe1008rides along the transverse wall1010aof the recess1010formed within shank113, and the concomitant camming action between end1008aand wall1010aforces shank to the right to withdraw into casement440. As is shown inFIG. 74, while approaching a fully unlocked orientation, the flat side126aof cam plate126will abut the interior side wall of casing440and prevent farther rotation of cylinder116and elliptical lobe1008within recess1010formed in shank113. Either alternatively, or simultaneously, and depending upon the dimensions of recess1010, shank113may engage lobe1008to terminate farther travel into casement440. A detent126cmay be formed to extend above the surface of shank113to engage an opposite flat side126bof cam plate126, as shown byFIG. 75, and prevent farther counterclockwise rotation of cam plate126, lobe1008and cylinder plug116when the shoulders of cam plate113adjacent to bolt112abut against the left interior wall of casement440.

Turning now toFIGS. 76 through 76D, an alternative embodiment of a cam lock is illustrated with a lever and electrical contact mounted on the exterior of cylinder plug116, rotating simultaneously with plug116while driving both arms1482,1484of a spring that together operationally couple cylinder plug116with cam plate1260. One end of arm1482engages a pivot1486at the distal end of lever1480while the opposite end of the other arm1484may engage a second pivot1490that may be mounted upon and extend above cam plate1260. A recess1012in shank113allows bolt112and its accompanying shank113to reciprocally travel relative to casement440while pivot post430anchors cylinder plug116coaxially with spacer post431within casement440.

FIG. 76, a top view showing the alternative embodiment is a partially unassembled state, illustrates the bolt112and the arms1482,1484in their corresponding positions while the lock is in its locked state with bolt112shown extending to the left and beyond casement440while the mechanism is in its locked state.

FIG. 76Ais a top view of the embodiment illustrated byFIG. 76, while in an unlocked state;

FIG. 76Bis a top view of the embodiment ofFIG. 76, shown after application of excessive torque to the keyway;

FIG. 76Cis an enlarged side elevational view illustrating the electrical contact system and insulating material in the embodiment illustrated byFIG. 76; and

FIG. 76Dis an enlarged side elevational view showing the electrical and data path through the embodiment illustrated byFIG. 76. Electrical contact716extending downwardly beyond the distal end of the blade502of key500, makes an electrical contact with a socket1502electrically coupled to one end of an electrically conductive contact wiper416that is electrically isolated by electrical insulators1504,1506from the electrically conducting elements of cylinder plug116. The other end of contact wiper416is coupled to spring1480that is, in turn, coupled to an electrical contact417mounted upon circuit board139and borne by cam plate126. The dashed lines presented inFIG. 76Dtrace the arms of electrical current from two electrically isolated parts of key500, namely blade502and terminal716. Current from the battery side of key500traces a path through contact716extending, for example, through, but insulated from, the blade502, through socket1502, spring contact wiper416, and spring-loaded contact pin417to circuit board139. Circuit board139distributes the battery voltage to the individual components of circuit130. A return, or local ground path may extend from a surface mount terminal on circuit board139that is located beneath the head of threaded fastener1013, through threaded fastener1013and an electrically conducting substrate1508beneath cam plate126and spacer1441, through upper pivot post1440, through casement cover128, and through cylinder plug116to the electrically conducting portion of the blade502of key500. Alternatively, or additionally, a return path may extend between circuit board139, threaded fastener1013, substrate1508, lower spacer1431, lower pivot1430, casement440, and through either cover128and cylinder plug116or through lower pivot430, lower spacer431and cylinder plug116, to the electrically conducting portion of the blade of key502. The pivoted mechanical connection between the distal end of spring loading of contact wiper416and the distal end of spring1480assures the continuity of electrical contact between the cylinder plug and circuit board139throughout 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 plug116and a second socket mounted upon circuit board139.

FIG. 77illustrates an alternative embodiment with the electrical contacts removed in order to clearly show the details of the mechanical components sited within casement440. Cylinder plug116is mounted within casement440to rotate around axis M, while cam1260is mounted within casement440to rotate around axis N. Axis N and cam1260are spaced radially apart from cylinder plug116and axis M. In this embodiment, lever416, in combination with a spring1880, operationally connects cylinder plug116with cam1260. Lever1486extends radially outwardly from cylinder plug116, and a boss1486mounted on the distal end of lever416pivotally engages a distal end of arm1882of spring1880. A coiled central length1884of spring1880joins arm1882to a second arm1888. The distal end of arm1882pivotally engages a boss1262extending axially outwardly from cam1260. The relative lengths of the interior of casement440and shank113restrict the throw of bolt112, and thereby limit the angular rotation of cylinder plug116and cam1260. Spring1880serves as a flexible buffer and torque limiting device between the angular rotation of cylinder plug116and cam1260.

In operation, when a key (not shown) able to demonstrate both mechanical conformance when inserted into keyway118and electronic conformance to the digital signature held by the key with the memory of circuit130(not separately shown) mounted upon circuit board139will enable circuit130to apply an electrical current to the coil of solenoid1202. The electrical current retracts both armatures1204radially inwardly and against compression spring1216. This axial withdrawal of both armatures1204enables the manual torque applied by to the key by the user, and by the key to keyway118in a clockwise direction, to turn lever1480clockwise and, in turn, force arm1882toward arm1888, thus forcing boss1262to rotate counter-clockwise around axis N. The rotation forces surface1209of cam nose1208out of the detent formed by arch1222and drives cam nose1208to the left, and thus accommodates counter-clockwise rotation of cam plate126against the bias force of spring1206(not separately shown inFIG. 77). While energized by circuit130, solenoid1202withdraws armatures1204in opposite axial directions by a sufficient distance to allow the distal ends of armatures1204to extend axially outwardly by an axial length that is less the distance between opposite side walls1212. In a locked, unenergized state solenoid1202has armatures1204extending to a coaxial length of somewhat less than the separation between opposite side walls1212; it is the energization of solenoid1202that retracts solenoid1202to an axial length less than least distance separating side walls1212, and permits the manual rotation of cylinder plug116to transmit the rotational force to cam1260via lever1480and spring1880. Elliptical lobe1008may be coaxially mounted with cam1260to rotate counter-clockwise around axis N, as indicated inFIG. 77, when a conforming key is inserted into keyway118and rotated clockwise. The distally entending end of lobe1008rides along the transverse wall of the recess1010formed within shank113, and the concomitant camming action between the distal end of lobe1008and the wall of slot1010forces shank113to the right, thereby withdrawing bolt112to withdraw inside casement440. This places the lock in an unlocked state. Although a key retainer holds the key (not separately shown) within key slot118, as long as no counter-clockwise force is applied to the key, cam nose1208remains outside of arch1222, 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 plug116, that, in turn, draws lever1480counter-clockwise, and pulls arm1882away from coil1884and arm1888, causing cam1260to rotate clockwise until the spring-loaded nose1208is released by fence1220to move to the right and into arch1222. Either a previous, or a subsequent interruption of electrical current to the coil of solenoid1202enables armatures1204to simultaneously move axially outwardly, in opposite directions, and to extend into the conforming slots1210formed in the circumferential wall of cam126. Completion of the counter-clockwise rotation of the key enables the key to be withdrawn from the retainer and keyway118.

Should excessive torque be applied to cylinder plug116as, 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 plug116around axis M, the combination of the engagement of nose1209and arch1222, and the distal ends of armatures1204and slots1210prevents spring1880from forcing cam1260to rotate around axis N. If cylinder plug116is 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 plug116does not provide direct access to either cam1260or to the components borne by cam1260. Access to cylinder plug116is further restricted by the relative thinness of casement440.

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.