Electronic cabinet/drawer lock system

An electronic wireless locking system comprising an external assembly and an internal assembly disposable on respective sides of a door or drawer. The external assembly includes a cover housing, a knob having a shaft, a card/credential reader, a status indicator, a wireless communication capability, a wire harness and a jump port plug. The internal assembly comprises a rotation link matable with the external shaft, a latch bolt, a circuit board and controller, and a locking mechanism including a rack and pinion gear set linking the rotation link with the latch bolt. A blocker inhibits the latch bolt from unlocking until authorized to rotate 90°, permitting the latch bolt to be withdrawn from a strike plate by manual rotation of the knob. An optional mechanical key override feature may also be provided. The system may further include a preload sensor and a device locked sensor.

TECHNICAL FIELD

The present invention relates to electronically-controlled lock systems, and also to cabinet latches; more particularly, to a system for securely latching a cabinet/locker door or drawer with an electronic lock mechanism; and most particularly, to a battery-powered electronic lock system responsive to a card reader or other authorization means, suitable for securely latching of a cabinet/locker door or drawer.

BACKGROUND OF THE INVENTION

Locking systems for securing cabinet/locker doors and drawers are well known in the prior art. Typically, such a system may comprise a simple spring latch actuated by manual turning of a key in an associated barrel lock.

More sophisticated door locking security systems are known wherein an electro-mechanical latching apparatus may be actuated by a card reader or key pad. The electromechanical mechanism is known to be mounted on either the cabinet/locker door or drawer or within the frame surrounding the cabinet/locker door or drawer. In either embodiment, the latching mechanism is actuated by a linear solenoid or small DC motor powered by an external DC supply, which is difficult for either a door-latching or drawer-latching application wherein the locking mechanism is mounted on the movable member.

Many prior art devices cannot easily be installed to engage with a mating part located above or to the side of the movable member. Most devices in the prior art cannot communicate with a centrally located access control system in a wireless mode. None of the prior art units have the capability of delaying the unlock signal until any preload on the release mechanism has been removed. In that case, the person trying to get into the cabinet or drawer would have to re-enter their code or re-swipe their card after the preload had been removed.

Also, none of the prior art devices have the ability to sense the presence of the locking member in its mating part which is mounted in the top or side wall of the cabinet. Finally, few if any prior art devices have a mechanical key override.

What is needed in the art is an electronic cabinet/locker lock system wherein the mechanism and circuitry are powered only by resident batteries which can be recharged by inductive power transfer, and the system can communicate wirelessly with a remote access control system.

Additionally, the art needs a lock which can be mounted in any of four positions relative to the door/drawer and frame; can sense a preload condition and delay the activation signal until the preload has been removed; sense the presence of the locking member in its locked position; and provide a key override.

It is a principal object of the present invention to securely lock a cabinet/locker door or drawer, and to make such a locking apparatus releasable by card reader or a keypad. Additionally, this lock system could be used on standard entry doors.

SUMMARY OF THE INVENTION

Briefly described, a wireless battery operated locking system in accordance with the present invention comprises a first (“external”) assembly disposable on the outside of a cabinet/locker door or drawer and a second (“internal”) assembly disposable on the inside of the cabinet/locker door or drawer.

The external assembly comprises an external cover housing; a rotatable knob having a rectangular shaft extendable through the door or drawer face to mate with the internal assembly; a card/credential reader; a status indicator; a wireless capability to communicate with a remote control center; a wire harness for connecting to the internal assembly; and a jump port plug and cap.

The internal assembly comprises a housing; a shaft rotation link matable with the external knob shaft; a latch bolt assembly connected to the shaft rotation link; a battery-powered circuit board and controller; a battery-powered locking and unlocking mechanism, a mechanical key override feature, a unit locked sensing feature, a preload sensing feature and a battery.

The battery powered locking mechanism includes a rack and pinion gear set linking the shaft rotation link with a latch sleeve supporting the latch bolt. A rotatable blocker inhibits motion of the latch sleeve unless such motion is authorized by the external card/credential reader. Upon such authorization, a battery-powered motor, such as a DC motor, a piezo motor or a linear piezo actuator rotates the blocker 90°, or otherwise linearly displaces the blocker, thereby permitting the latch bolt to be withdrawn from latched engagement with a jamb-mounted strike plate by manual rotation of the knob, shaft, shaft rotation link, and pinion gear (all through a bearing located in the internal module).

DESCRIPTION OF THE PREFERRED EMBODIMENT

There exists the need for a wireless battery operated locking system that has a spring latch mechanism which automatically locks a cabinet/locker door or drawer when pushed closed. The system must also be able to change to an unlocked state when the system's card reader is presented with valid credentials. Additionally, the system must support being surface-mounted on either a cabinet/locker door or a drawer front face, configured in any of four positions. These positions are in axial rotation about the knob with minimum intervals of 90°, as shown and described more fully below inFIGS. 6 through 8.

Referring toFIGS. 1 through 5, a general layout is shown for a wireless battery operated locking system10for locking a cabinet or locker door or drawer12(all referred to herein below as “cabinet door”) in accordance with the present invention.

System10includes external assembly14, including a rotatable knob16and internal assembly18including a battery-operated locking mechanism20mounted on respective outer and inner surfaces22,24of cabinet door12. An optical or magnetic card/credential reader26is disposed in external housing cover28, with card/credential reader antenna30, status indicator32, knob16and attached shaft34, and a jump port plug cap36. A jump port plug, hidden by the jump port plug cap36, addresses the issue of occasional low battery power. The jump port is available to apply emergency external power to the system. A wiring harness38for connection to internal assembly18is connected to a circuit board25, reader26, antenna30, status indicator32, and a jump port (not visible) under cap36. Antenna30communicates with a hub connected to a remote access control system (not shown).

Battery-powered locking mechanism20comprises cover housing39, latch bolt40, shaft rotation link42, battery cover44, housing or case46, sensor switch cover48, security board cover50, a small motor assembly84(Shown inFIG. 11); a circuit board45which includes a processor for conducting encrypted communication with external assembly14; a motor driver; and a battery. There is a switch in the circuit board45which monitors the position of the latch bolt sleeve to detect if there is a preload on the knob, as described in detail below.

Wiring harness38connects the external and internal assemblies14,18so that they can communicate with each other and so that electronics in the external assembly can be powered by the battery. Wiring harness38is affixed to the external assembly; during installation, harness38is fed through a hole in cabinet door12then the external assembly is installed on the cabinet door front22. Wiring harness38is then plugged into the internal assembly which then is installed on the inside surface24of cabinet door12. Alternatively, the wiring harness38is fed through a through-gap51within the internal assembly, with the internal assembly then secured to the inside surface24of the cabinet before connecting the wire harness to the internal assembly.

Referring toFIGS. 6 through 8, a sequence is shown for changing the relative orientation between external assembly14and internal assembly18, as may be required for any cabinet door, locker door, and drawer application, to accommodate door/drawer handing and top or side locking. This is an important advantage of the present invention. Attachment/follower ring52includes a flat ring portion54having at least two molded nut platforms55extending rearward there from. In the case of two nut platforms55, the platforms are spaced 180° apart, while a ring portion having four molded nut platforms55has platforms spaced 90° apart. Housing28includes a shallow well56having a central opening58for passage of shaft34there through and four openings60disposed quadrilaterally for receiving in opposed pairs platforms55to mate with mounting screw holes62in internal assembly18. As shown inFIGS. 7 and 8, this arrangement of platforms55and openings60allows an installer to configure external and internal assemblies14,18in any of four different positions rotated about knob16in increments of 90°. Two such positions are shown inFIGS. 7 and 8.

Referring toFIGS. 9 and 10, a jamb-mounted strike plate64includes a magnet66that activates reed-switch sensor68embedded in latch bolt40, allowing system10to detect if cabinet door12is fully closed and the lock mechanism is in locked position. In certain embodiments, the strike plate's magnet is placed within the strike plate distal the latch bolt so as to minimize or prevent false readings by the sensor when the door is open.

FIG. 11shows components and operating relationships of a partially exposed internal structure of locking mechanism18. Pinion gear70is linked to shaft rotation link42and rotates 45° to move lock bolt sleeve72via an integral rack gear74to the home position at locked state, driven by sleeve return spring76. Pinion gear70, when driven by manual rotation of knob16and shaft34, moves sleeve72down to the unlocked position, bringing with it latch bolt40. The returning force for latch bolt40is provided by spring78. Connecting arm80, fixed to latch bolt40, links sleeve72and latch bolt40when gear70is activated, forcing sleeve72and latch bolt40to move together to the unlocked position. Connecting arm80also keeps latch bolt40from being removed from the assembly.

A blocker82attached to motor assembly84prevents sleeve72from being moved to the unlocked position by rotation of gear70, as shown inFIG. 11. Thus, with blocker82in place as shown, latch bolt40is held in a locked position. Upon application of valid credentials to external assembly14, motor assembly84is energized and blocker82is rotated 90° to get out of the path of sleeve72at unlock position. This allows sleeve72and latch bolt40to move, powered by manual rotation of knob16, so that latch bolt40ends up recessed into internal assembly18and cabinet door12can be opened.

Referring again toFIGS. 5 and 11, a mechanical key override feature is provided permitting manual movement of latch bolt40to an unlocked position while sleeve72is held by blocker82in a locked position. Extension81of connecting arm80projects laterally from latch bolt40and passes through clearance slots in sleeve72and housing cover39. A conventional, key operated cam lock89(key side of the cam lock not shown) mounted in door12adjacent extension81may be used to mechanically move connecting arm80and latch bolt40to an unlocked position upon rotation of the key operated cam lock in the event of a power failure to motor assembly84. Extension81may be omitted in applications where a mechanical override feature is not needed.

A cylindrical feature86on latch bolt40allows the reed switch wires83to pass through it, making them concealed and protected while latch bolt40moves up and down. Channel88in case46allows freedom of movement of the wires inside the channel and for the wires to stay connected to a secure board therein (not visible) while latch bolt40moves. Channel88further functions as a guide, in conjunction with cylindrical feature86, to limit side to side movement of the latch bolt as the latch bolt moves up and down.

Referring toFIG. 12, a knob rotation switch87allows system10to confirm that no pressure is being applied to turn knob16when a valid card/credential is presented to reader26. This prevents a preload from being applied to blocker82which could prevent the blocker from releasing the sleeve upon motor activation. If a person tries to anticipate the unlocking of the mechanism by trying to rotate knob16, switch87opens and prevents motor assembly84from trying to rotate blocker82. Switch87must always be depressed by the sleeve72when a valid card/credential is presented to allow activation of motor assembly84and rotation of blocker82to unlock the mechanism, as described above. Switch87is mounted onto internal assembly18and is acted upon by a movement of sleeve72upon initial rotation of turn knob16, such that when the latch40is resting and locked, the position of sleeve72depresses switch87completing the circuit to the motor.

In one aspect of the invention, in the case where a premature turning of the knob is followed by an unlock signal from a presentation of the card/credential, the unlock signal to the motor may be stored and applied at a later time once the turn knob pressure is released. In the case of the turn knob having pressure applied when the motor assembly is attempting to relock the unit, the relock signal may also be stored until the pressure has been released from the turn knob. This is particularly important to make certain that the lock has been re-locked and the door or drawer thus secured.

Referring now toFIGS. 13 and 14, depending upon the thickness of the door or panel, shaft34protruding rearwardly from external assembly14may be further lengthened by provision of shaft extension35. Shaft extension35is adapted to have a first end snuggly fit within the through bore of shaft34. A bolt37is then threaded through the shaft extension35and secured within shaft34. Thus, the extended shaft mates with and engages shaft link42within the internal assembly upon rotation of knob16.

In operation of system10, when a security card is held up to the reader, the reader sends the card information wirelessly, such as by way of antenna30to a remote hub which asks an access control system if the card is valid. The remote hub replies to the cabinet lock system with the validation signal as reported by the access control system. If the card is valid, the external assembly14sends an encrypted data packet to the internal assembly, which decodes it and drives motor assembly84to unlock the latch. After a set period of time, the latch is relocked by driving motor assembly84in an opposite direction.

The circuit board45in the internal assembly constantly monitors the switch mounted in the latch bolt to determine if the cabinet door is closed and reports this status back to the circuit board25in the external assembly so that the data can be sent to the access control system. The switch for detecting load on the knob is monitored only when the motor assembly84is trying to unlock or relock the device. If there is a pre-load on the knob, the system will wait until the knob is released before attempting to unlock or relock.