Abstract:
A two-point locking system for providing controlled access through a doorway is described comprising a controlled deadlatch assembly and a magnetic lock assembly. The controlled deadlatch assembly comprises (i) a deadlatch for selectively latching and unlatching a door, (ii) an input control device for selectively controlling the deadlatch, and (iii) a first wireless transmitter for transmitting a magnetic lock control signal. The magnetic lock assembly comprises (i) a metal housing unit, (ii) an armature plate, (iii) an electromagnetic element coupled to the housing unit and aligned to magnetically engage with the armature plate when selectively electrically energized, and (iv) a wireless receiver capable of receiving the magnetic lock control signal from the wireless transmitter. The magnetic lock control signal will typically disengage the magnetic lock assembly when the controlled deadlatch assembly is unlatched (thus unlocking the door and allowing access) and engage the magnetic lock assembly when the controlled deadlatch assembly is latched (thus locking the door and not allowing access). A second wireless transmitter can also be added to the magnetic lock assembly to communicate to a second wireless receiver at the controlled deadlatch assembly to provide two-way wireless communication between the two locking points.

Description:
FIELD OF THE INVENTION 
     This invention is generally directed to an access door locking system including a magnetic lock. More specifically, the access system of the present invention utilizes a two-point locking system integrating a deadlatch and a magnetic lock in a manner requiring no wiring between the controlled deadlatch assembly (typically located by the door handle) and the magnetic lock assembly (typically incorporated along the top of a door frame). 
     BACKGROUND OF THE INVENTION 
     There exists in the prior art a myriad of deadlatches and magnetic locks in the prior art to control ingress and egress through a door. Additionally, there are numerous integrated or so called two-point systems which incorporate both a controlled deadlatch assembly and a magnetic lock assembly. One common example is a controlled deadlatch activated by a panic bar which not only will release the deadlatch but also send an electrical signal through wiring that will release a magnetic lock. In such an example, an alarm might also be activated. 
     While the actual operation of properly installed two-point locking systems has proven to be relatively effective, installation has proven both difficult and time-consuming. Due to the space constraints of the door frame, the hard wiring between the knob assembly (where the controlled deadlatch assembly is typically located) and the magnetic lock assembly (which is typically coupled to the top of the door) is often difficult and can result in improper connections or actual physical damage to the door. Furthermore, it is often easy to tamper with such wiring. 
     In either single point magnetic locking devices or two-point locking systems, any of a number of input control devices can be incorporated. Conventional control devices include keypads, card swipes, proximity card readers, push buttons, passive infrared detectors, retinal scanners, fingerprint detectors, etc. However, whether in single point or two-point locking systems, and regardless of the type of control device (or the attached deadlatch assembly) utilized, the prior art requires the installation of proper wiring between the input control device and the remotely located magnetic lock assembly. Again, expensive and difficult installing is required. Additionally, lock installers typically are mainly mechanically skilled thus requiring a second installer with electrical skills. 
     In addition to the difficulty encountered by installers of conventional magnetic locks which require hard wiring between the control device and a magnetic lock, it has been shown that consumers have been reluctant to incorporate lock systems which require significant installation through a door frame, particularly in retrofit applications. Thus, the proliferation of magnetic locks has proven difficult. 
     It is, therefore, a primary object of the present invention to provide a new and improved magnetic locking system to control door access and egress. 
     It is another object of the present invention to provide a new and improved magnetic locking system to control door access and egress in either single point or two-point applications. 
     It is yet a further object of the present invention to provide a new and improved magnetic locking system to control door access and egress which requires no hard wiring between an input control device and the magnetic lock assembly. 
     It is yet another object of the present invention to provide a new and improved magnetic locking system to control door access and egress which provides easy adaptability of a plurality of access applications. 
     It is still another object of the present invention to provide a new and improved magnetic locking system to control door access and egress which provides detailed audit trail information over an infrared link. 
     It is yet an additional object of the present invention to provide a new and improved magnetic locking system to control door access and egress in which additional infrared transmitters may be incorporated in order to expand the range for activating a control device. 
     It is yet still another object of the present invention to provide a new and improved magnetic locking system to control door access and egress in which a remotely located user can permit or deny access or egress from the protected premises. 
     Other objects and advantages of the present invention will become apparent from the specification and the drawings. 
     SUMMARY OF THE INVENTION 
     Briefly stated and in accordance with the preferred embodiment of the present invention, a two-point locking system for providing controlled access through a doorway is described comprising a controlled deadlatch assembly and a magnetic lock assembly. The controlled deadlatch assembly comprises (i) a deadlatch for selectively latching and unlatching a door, (ii) an input control device for selectively controlling the deadlatch, and (iii) a first wireless transmitter for transmitting a magnetic lock control signal. The magnetic lock assembly comprises (i) a metal housing unit, (ii) an armature plate, (iii) an electromagnetic element coupled to the housing unit and aligned to magnetically engage with the armature plate when selectively electrically energized, and (iv) a wireless receiver capable of receiving the magnetic lock control signal from the wireless transmitter. The magnetic lock control signal will typically disengage the magnetic lock assembly when the controlled deadlatch assembly is unlatched (thus unlocking the door and allowing access) and engage the magnetic lock assembly when the controlled deadlatch assembly is latched (thus locking the door and not allowing access). A second wireless transmitter can also be added to the magnetic lock assembly to communicate to a second wireless receiver at the controlled deadlatch assembly to provide two-way wireless communication between the two locking points. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as the invention herein, it is believed that the present invention will be more readily understood upon consideration of the description, taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a schematic illustration of the outside of a door incorporating a magnetic locking system in accordance with the present invention; 
     FIG. 2 is a schematic illustration of the inside of a door incorporating the magnetic locking system in accordance with the present invention; 
     FIG. 3 is an electrical block diagram of the controlled deadlatch assembly portion of a two-point locking system incorporating the magnetic locking system in accordance with the present invention; and 
     FIG. 4 is an electrical block diagram of the magnetic lock assembly portion of a two-point locking system incorporating the magnetic locking system in accordance with the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Both FIG.  1  and FIG. 2 include a door  10 , a door frame  12 , a magnetic lock assembly  14 , and a controlled deadlatch assembly  16 . FIG. 1 represents the outside of door  10  whereas FIG. 2 represents the inside of door  10 . Magnetic lock assembly  14  is shown in shadow in FIG. 1 since it is preferred in most applications to have magnetic lock assembly  14  installed on the inside (or secured side) of door  10  for security purposes. However, magnetic lock assembly  14  obviously can be attached to either side of door  10  and door frame  12 . 
     Controlled deadlatch assembly  16 , as depicted in FIG.  1  and FIG. 2, actually is a combination input control device and deadlatch/door handle apparatus. In the embodiment shown, a keypad  18  is incorporated as the input control device. If an acceptable combination is punched into keypad  18 , a predetermined delay time will commence in which a user can turn a door handle  20  to release a deadlatch  22  and permit entry into the secured premises. Keypad  20  can be replaced with a card swipe reader, a proximity card reader, a wireless receiver, or any other available input control device to release deadlatch  22 . Furthermore, in certain applications, door handle  20  need not be activated at all and instead a motor can automatically lock or unlock deadlatch  22 . Moreover, controlled deadlatch assembly  16  can incorporate a liquid crystal display (LCD)  24  such as shown in FIG. 1, a light emitting diode (LED), and/or a buzzer to indicate to a user that a proper code has been entered or to provide other user indicia. The type of controlled deadlatch assembly incorporated while developing the present invention was the DL 2700 manufactured by the assignee of the present invention. 
     Magnetic lock assembly  14  includes a housing  15  which is typically comprised of a tamper proof metal. Housing  15  is, in the preferred embodiment, securely coupled to door frame  12 . Thus, in actuality, housing  15  would not appear visible in FIG. 2 if door  10  were shut. On the outward facing portion of housing  15  is an electromagnetic element  17  which is capable of mating with an armature plate  19  that is appropriately positioned on door  10 . Upon electrical energization of electromagnetic element  17 , armature plate  19  is electromagnetically bonded to electromagnetic element  17  and hence metal housing  15 . Electromagnetic element  17  and armature plate  19  have generally complimentary contact surfaces. Armature plate  19  is therefore mounted to the upper corner of door  10  so that armature plate  19  and electromagnetic element  17  align and are in mutual surface-to-surface contact when door  10  is in the closed latched position. Various combinations and components of magnetic lock assemblies are well known in the art. For instance, it is possible to move housing  15  to door  10  and armature plate  19  to door frame  12 . 
     Referring to FIG. 2, a keypad  26  is illustrated which also requires proper entry by a user to exit the premises protected by door  10 . An exit input control device, such as keypad  26 , is typically incorporated in high security applications such as airports, vaults, etc. Many applications do not require the use of an input control device on the inside of the protected premises (i.e., to protect egress). However, it is typical to place a power supply on the inside of the door for security purposes. Again, reference is made to the DL 2700 manufactured by Alarm Lock Systems, Inc. and numerous other controlled deadlatch assemblies well known in the art. 
     Magnetic lock assembly  14  (with the exception of an infrared transparent window  28  which will be described later herein) can be of various sizes and strengths as is known in the prior art. In order to comply with most fire code regulations, magnetic lock assembly  14  is typically designed to operate from 12-24 volts AC/DC. An optional audio speaker  29  can also be provided. 
     In the prior art, in order for the magnetic lock assembly  14  and controlled deadlatch assembly  16  to operate properly in conjunction, it is necessary to hardwire the two assemblies through wires extending through door frame  12 . However, by incorporating the electrical circuitry of FIG. 3 in controlled deadlatch assembly  16  and the electrical circuitry of FIG. 4 in magnetic lock assembly  14 , all hard wiring between magnetic lock assembly  14  and controlled deadlatch assembly  16  can be eliminated. 
     Referring to FIG. 3, a power supply  30  will be applied from the same battery incorporated to power controlled deadlatch assembly  16 . An IR receiver photodiode  32  is incorporated which can receive signals from either magnetic lock assembly  14  (as described below) or a keyfob  34  which, in one embodiment, can be utilized as an input control device. A first amplifier  36 , which is controlled by a bandwidth control signal from an infrared communication microprocessor  38 , receives the electrical signal from receiver photodiode  32 , passes its output through a resister  40  which, in turn, passes the signal through a second amplifier  42 . Second amplifier  42  has an automatic gain control (ACG) feedback circuit  44  which is incorporated to prevent interference from other infrared signals, other locks, etc. Such ACG circuits are known in the prior art. 
     The output of second amplifier  42  is fed into both a low frequency detector  46  and a high frequency detector  48 . Low frequency detector  46  provides a wake up signal output  50  to microprocessor  38 . In essence, wake up signal output  50  prevents the unnecessary drain of power from power supply  30  and prepares infrared communication microprocessor  38  to receive data from high frequency detector  48  along a data input line  52 . 
     Once infrared communication microprocessor  38  determines that the conditions and signals are proper to unlock the door, an output signal is generated to a motor driver  54  which in turn activates a lock motor  56 . Lock motor  56  can be made to move deadlatch  22  to either a locked or unlocked position. 
     In order to also unlock magnetic lock assembly  14 , a signal is also sent from infrared communication microprocessor  38  to an infrared transmitter  58  and on to an infrared transmitter  60 . The infrared magnetic lock control signal transmitted from infrared transmitter  60  is capable of being received by magnetic lock assembly  14 . 
     Still referring to FIG. 3, a PIR sensor  62  and a “request to exit” sensor board  64  is also shown connected to infrared communication microprocessor  38  along PIR data input line  66 . This request to exit feature is typically incorporated inside the door and permits the unlocking of a door when PIR sensor  62  senses movement within a predetermined range of door  10 . When a person moves within a predetermined proximity of door  10  on the inside, door  10  will unlock to permit that person to leave the premises. Optional request to exit techniques such as a push button, a “wiggle” switch, a touch sensor switch, etc. may also be incorporated. A two-way serial data input/output line  68  is coupled between a lock control and database microprocessor  70  and infrared communication microprocessor  38  to either upload or download information. Audit trail information downloaded to lock control and database microprocessor  70  can be transmitted through an infrared transmitter driver  72  and then onto an infrared transmitter  74 . Infrared transmitter  74  can provide information to an infrared printer output so that an installer can gather audit information. Alternatively, lock control and database microprocessor  70  can transmit audit trail information to a download connector  76  which can be directly coupled to a hand-held device to also receive audit trail information. A keypad  78  permits a user to modify the system by, for example, adding new users, changing permissible times of entry, adding new input control devices, etc. 
     Turning now to FIG. 4, the circuitry associated with magnetic lock assembly  14  is shown. A powered infrared receiver module  80  is capable of receiving the transmitted infrared signal from infrared transmitter  60  which is part of controlled deadlatch assembly  16 . The received data is transmitted along a data input line  82  to a magnetic lock communication and control microprocessor  84 . After microprocessor  84  processes the received data, and in appropriate circumstances, a signal can be transmitted to a driver  86  to either activate or deactivate a magnetic lock  88 . Infrared receiver module  80  can also receive signals from other transmitters besides infrared transmitter  60 . For instance, a signal from keyfob  34  from outside door  10  can be received through infrared transparent window  28 , as shown in FIG.  1 . Magnetic lock  88  as shown in FIG. 4 can represent magnetic lock assembly  14  of FIG.  1  and FIG.  2 . 
     Microprocessor  84  also can provide an output signal to a relay driver  90  and ultimately to a relay  92 . Relay  92  can be incorporated to couple numerous other devices such as an alarm system. Microprocessor  84  can also be utilized to control a speaker  94  and/or a locked indicator LED  96 . 
     Two—way wireless communication from magnetic lock assembly  14  to controlled deadlatch assembly  16  can also be provided by means of coupling microprocessor  84  to an infrared transmitter driver  98  and an infrared transmitter  100 . Infrared transmitter  100  provides a control signal capable of providing information, including audit trail information, to infrared receiver photodiode  32  of FIG.  3 . By incorporating the wireless communications between magnetic lock assembly  14  and controlled deadlatch assembly  16  in accordance with the present invention, numerous potential applications become possible. For instance, additional infrared transmitters for remote mounting can be provided to allow fixed remote release operations such as push buttons, or interfacing to existing release mechanisms. These transmitters can be capable of ceiling mounting for unobstructed communications with the locking system. These transmitters may be designed as relay units for use with shorter range devices such as a keyfob in order to expand their range; it will only be necessary for the keyfob signal to reach the remote transmitter for relaying the signal to the locking device. By utilizing this technique and further incorporating CCTV technology, a remotely located individual can release the locking mechanism upon seeing an individual whom access should be granted. Instead of CCTV, an audio-based intercom system might also be utilized. Additionally, with the use of two-way wireless communication, magnetic lock assembly  14  can be used to control the latching and unlatching of controlled deadlatch assembly  16  as opposed to the direction of control described in the preferred embodiment herein whereby initial control is at controlled deadlatch assembly  16 . 
     Although the preferred embodiment has been described wherein controlled deadlatch assembly  16  includes a deadlatch  22 , the deadlatch need not be incorporated. The wireless communication from the input control device can be transmitted to the magnetic lock without having any control over a deadlatch. The electrical assembly of the present invention also permits the incorporation of buzzers, door chimes, etc. as may be desired by the user and available in the prior art. In any embodiment, power wiring would be required only to the magnetic lock assembly to comply with standard fire codes. 
     It will be apparent from the foregoing description that the present invention provides a new and improved locking system which permits ease of installation and wireless communication between the magnetic lock assembly and the controlled deadlatch assembly. Many control input devices and desired audit trail information techniques can still be utilized. 
     While there has been shown and described what is presently considered to be the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the broader aspects of this invention. For instance, although the magnetic lock assembly has been shown incorporated on the top of a door frame, such magnetic lock assemblies can indeed be incorporated elsewhere on the door. Furthermore, while an infrared transparent window has been shown on the magnetic lock assembly, such an infrared transparent window can also be incorporated on the controlled deadlatch assembly to permit wireless communication from either side of the door. Moreover, although a standard door has been shown for illustrative purposes, any type of access door, gate, window, etc. can be protected by the locking apparatus of the present invention. Additionally, the term “deadlatch” as used herein shall include a dead bolt, another magnetic lock, a push button lock or any other locking means. It should also be noted that although microprocessors have been incorporated in the preferred embodiment based on ease of use, discreet logic components may be used. 
     It is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true scope and spirit of the invention.