Patent Abstract:
A light fence represented by aligned apertures in a plurality of wheels permits the passage of a light beam to a sensor to activate an electro-mechanical control for a lock. Such an arrangement avoids the sound-producing mechanical action of the typical tumbler lock and safeguards discovery of the opening combination. Rather than the typical case of a numerical sequencing combination, a novel approach is taken by using visual pattern recognition to align the apertures. The electro-mechanical control of the present invention additionally features optimized energy use, customizable settings, precision positioning, and an expansion of possible combination permutations by including direction of rotation.

Full Description:
FIELD OF THE INVENTION 
     This invention relates to combination locks, and more particularly to an electromechanical control mechanism using non-numeric encoding. 
     BACKGROUND OF THE INVENTION 
     Safes, vaults, lockers, and keyless entries, among other types of secure systems, use locks requiring a unique combination for access. Typically, the combination is a set of numbers and rotational sequences which align tumblers to a predetermined orientation. The tumblers make a sound when dropping and this “signature” can reveal the combination when sophisticated listening devices are used. Furthermore, telltale wear patterns can develop with mechanical abrasion and can similarly be detected with sensitive equipment. 
     One method of eliminating the mechanical action of tumblers is to use an optical alignment system. U.S. Patent Application 2206/0037374 to Skelly teaches the use of a light beam received by a sensor through aligned holes in three concentric tubes rotating about the common axis. The tubes can be manipulated by interfacing members on each tube such that a series of discrete rotations of the innermost tube, twisting clockwise and counterclockwise, bring the three into an alignment of the holes. The aligned holes enable a beam originating in the center to pass through to a sensor located outboard. The receipt of the beam passes a command to an unlocking mechanism. There are no tumblers to drop and no sound clues to witness the angular settings of the combination. 
     Similarly, in U.S. Pat. No. 2,008,150 to Nelson, a light signal traversing a “fence” of aligned holes in a series of disks mounted on a common shaft provides the means for controlling a lock. The combination is the individual orientation of each disk thus aligned. Except for one disk corresponding to a dial, the disks are free to rotate on the shaft, and in like manner to Skelly, each can be set into position by means of rotating the dial and engaging an interfacing geometry. The problem with such a system, however, is that the subsequent rotation of the moving part could disturb the prior setting of a positioned part. The common shaft, the case of Nelson, or the nested tubes, in the case of Skelly, would inevitably create rotational drag on co-journaled elements. What is missing in the prior art is a light fence where each disk can be individually set and registered to position. 
     The energy source for such opto-electrical systems is typically supplied by battery. If the light is rendered always on, or if it is switched on to initialize the combination setting procedure, battery life will be consumed and ultimately require service. The benefit in safety attendant to such an optical device is thus offset by the inconvenience of maintenance. It would be an advantage, therefore, to provide for conservation of energy use and extended battery life in the design of such systems. 
     Both Skelly and Nelson use number indices to orient the combination. Even if security breach were not a risk, number patterns are not particularly user-friendly. They can be hard to remember, especially if they are randomly chosen and not resettable in after-market use. Research has shown that visual patterns are processed in the brain in a different way than word or number patterns. Not only is visual recognition instantaneous, it is also easier to remember. Furthermore, visual patterns do not lend themselves to discovery by guessing, in the way that knowledge of an individual&#39;s background can sometimes suggest a number combination. Some means to set a visual pattern combination, therefore, would represent a needed improvement. 
     SUMMARY OF THE INVENTION 
     In view of the above-mentioned unfulfilled needs, the present invention embodies, but is not limited by, the following objects and advantages: 
     A first objective is to provide an optical means for controlling a lock. 
     A second objective is to define the optical means in terms of a light fence represented by concentrically-journaled rotating wheels. 
     A third objective is to render each wheel individually settable and thereby eliminate any drift in position caused by coaction. 
     A fourth objective is to provide a means for positively locating each such wheel. 
     A fifth objective is to provide a visual recognition means for identifying the combination representing the orientation of each wheel in alignment. 
     A sixth objective is to improve battery life by shortening the use period to a brief pulse. 
     A seventh objective is to extend the possible combination permutations by including rotation direction as an argument. 
     An eighth objective is to provide a logic process for validating an unlock command. 
     A ninth objective is to provide a means for customizing the combination. 
     In a preferred embodiment of the present invention, an electro-mechanical control for a lock comprises a plurality of mostly tubular shafts journaled concentrically about a common axis. Each shaft is individually rotatable about the axis. Each inner shaft extends from its outer in both axial directions. A matching plurality of wheels is fixed to one end of each shaft. The wheels each have an aperture at a common radial distance from the common axis. A plurality of dials is fixed to the other end of each shaft to thereby manipulate each wheel. Each dial has a preferred orientation corresponding to an alignment of the apertures. 
     The preferred embodiment further comprises a means for indicating the preferred orientation for each dial. A light source is positioned at one end of the plurality of wheels at the common radial distance. The light source is connected to a source of power through a means for connecting. A photo sensor is positioned on the other end of the plurality of wheels to detect a beam of light from the light source passed through the aligned apertures. Finally, a means is provided for controlling the opening of the lock when the dials have been set to the preferred orientation. 
     In a particular preferred embodiment, a means is provided for determining whether each wheel rotation was clockwise or counterclockwise. In this case, the means for controlling the opening of the lock includes the preferred direction as well as the preferred orientation. This effectively doubles the number of combination permutations. 
     In another particular preferred embodiment, the plurality of concentric shafts is provided the additional degree of freedom to translate back and forth along the common axis. This translational movement facilitates a push-pull contact means for connecting, which means can be actuated by a push on the shafts when the last preferred orientation is set. Such a mechanism appreciably reduces power requirements. 
     In still another particular preferred embodiment, a pawl and detent mechanism is provided to positively indicate and hold registration of the orientation of each wheel. The detents are arrayed to facilitate the preferred orientation. The pawls, when mounted on beam springs, responsively retract the shafts and bias the contact to the open position. 
     This provides a positive locating mechanism and further facilitates the optimization of power by maintaining a pulse-like interval for contact. 
     In yet another particular preferred embodiment, the means for indicating is one or more features on each dial the juxtaposition of which presents in a particular visual pattern when in the preferred orientation. The feature could be a distinguishing physical feature or could be a selected color. This provides a visual means for recognizing a combination represented by the preferred orientations and avoids the dependence on a numerical sequence. 
     In still yet another particular preferred embodiment, a logic process for a microcontroller, serving as the means for controlling, is provided. The logic process comprises the steps of comparing a rotation direction from an initial instance in stored memory to a current instance from an electro-magnetic sensor for each rotation of each dial; storing the information in the event of a match and discarding the information in the event of a mismatch; comparing an instance of light detection from the photo sensor with stored event information; sending a command to unbolt the lock mechanism in the event of a match of a light instance with a set of stored direction instances equaling the plurality and ignoring the light instance in the event of a mismatch; and, erasing stored direction instances in either a match or mismatch event associated with a light instance. 
     As this is not intended to be an exhaustive recitation, other embodiments may be learned from practicing the invention or may otherwise become apparent to those skilled in the art. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood through the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
         FIG. 1  is a front perspective view of the invention; 
         FIG. 2  is a back perspective view of the invention; 
         FIG. 3  is a side plan view of the invention; 
         FIG. 4  is a front plan view, illustrating a first embodiment of a visual means of indicating; 
         FIG. 5  is a front plan view, illustrating a second embodiment of a visual means of indicating; 
         FIG. 6  is an exploded perspective view of the invention; 
         FIG. 7  is a front perspective view of the invention, illustrating a means for customizing the preferred orientations; 
         FIG. 8  is a block circuit diagram, illustrating power and sensor connections; and 
         FIG. 9  is a logic process diagram for a microcontroller. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following is a brief description of function and a presentation of a featured novel concept. Referring to  FIGS. 1 and 2 , an electro-mechanical control  1  controls the opening of lock  2  (not shown). Lock  2  is a bolt or latch system which receives a signal from the electro-mechanical control  1  when preset parameters, otherwise known as a combination, are satisfied. Typically, these parameters are a set numbers dialed in a unique sequence. A novel feature of the present invention is to represent such a set of parameters in an easy to recognize and remember visual pattern. Such a pattern is shown in  FIG. 1 , where dials  40  display indicator notches  46  in particular angular orientations. Two embodiments of visual pattern  43  are shown in head-on views in  FIGS. 4 and 5 . 
     The pattern of the indicator notches  46  matches to an alignment of apertures  31  on wheels  30 , which are connected to dials  40  by shafts  20  ( FIG. 6 ). The alignment of apertures  31  permits light beam  52  ( FIG. 3 ) to be passed from light source  50  to photo sensor  60 . The receipt of the light beam  52  is the augment for passing a command to the lock  2  whereby an opening action is initiated. 
     Visual patterns, such as the one of  FIG. 4 , are culturally ubiquitous. Orientations involving twelve index positions, for example, such as can be found on an analog clock face, are easily discriminated. In the instant example, the orientations read, from left to right, 11 o&#39;clock, 12 o&#39;clock and 1 o&#39;clock. This reading would be apparent even without indicia markings, as evidenced by certain blank clock faces sold under designer names. 
     The following is a detailed description of the present invention. Referring to  FIG. 6 , a collar  12  of chassis assembly  10  forms a housing for a plurality of shafts  20 . The shafts  20 , essentially of tubular construction, except for the innermost, assemble one inside another to form a concentrically-journaled composite. Each inner shaft extends from its outer in both directions along a common axis  21  ( FIG. 3 ). Each shaft  20  has a proximal end  23  and a distal end  22 . The distal ends  22  of the assembled shafts  20  are located in interior  13  of chassis assembly  10 , the proximal ends  23  extending outward therefrom. Each shaft  20  is individually rotatable about common axis  21 . 
     A particular multiplicity of index positions, such as twelve in the instant case, is represented by parallel grooves  24  in the exterior walls of shafts  20 . Wheels  30  assemble to shafts  20  in the interior  13 . Each shaft diameter is matched by a bore diameter in a corresponding wheel, and bosses  35  of wheels  30  are interposed with parallel grooves  24  when assembled to the cascaded extensions of distal ends  22 . The interposition of bosses and grooves couples the wheel to the shaft, similar to the splined-shaft couplings of common usage. In a similar manner as wheels, dials  40  with dial bosses  47  assemble to proximal ends  23  to form a unitary rotational element with wheel and shaft. Each wheel  30  has the aperture  31  positioned a common radial distance from common axis  21 . 
     The assembled components are shown in  FIG. 3 . A translational degree of freedom is provided by a gap  55 , which is located both inside and outside of chassis assembly  10 . The gap permits an open position for a push-pull contact  54 . Push-pull contact  54  is closed by pushing on dials  40  to bridge gap  55  through the translation of shafts  20 , thereby providing means for connecting  53 . Means for connecting  53  links a power source  51  (not shown) to the light source  50  for an activation pulse. The power source  51  may be a battery  56  ( FIG. 9 ), such as a Direct Energy Conversion Cell (DEC) having a multi-year life span. The light source  50  may be an energy-conserving LED  57  ( FIG. 9 ), or any other battery-operated light emitter. The photo sensor  60  is positioned opposite the light source  50 , on the opposite side of wheels  30 , and in a line connecting light source  50  and apertures  31 . Photo sensor  60  may be a photo diode  62  ( FIG. 9 ), or similar light-sensitive receiver. Both light source  50  and photo sensor  60  may be hooded to selectively target the light source, thereby defeating any attempt to open the lock by “light flooding”. The outboard end of collar  12 , represented by mounting shank  15 , is an allowance for through mounting, such as through the wall of a safe. In the sense of  FIG. 3 , all structure to the right of the shank  15  is external to the safe, and everything to the left is internal. 
     Referring to  FIGS. 2 and 3 , wheels  30  have detents  33  on one facing. Detents  33  are evenly arrayed in a circle and match in number to the index positions embodied by the parallel grooves  24 . Pawls  36 , at the end of beam springs  34 , interface with the detents  33  such that the rotational position of each wheel  30  is positively registered. The beam springs  34  provide sufficient flex for the transition of wheels  30  from one detent position to another, snapping into the next detent when the corresponding dial is turned. In this manner, sequential settings may be made without disturbing a prior position, said position now held fixed by an engaged pawl and detent. The pawl and detent mechanism also provides for discrete dial locating so that angular discrimination is not left to judgment. Finally, beam springs  34  bias the push-pull contact  54  to the open position and instantly retract a push with a pull. 
     A means for determining rotation  80  is provided by electro-magnetic sensors  81  positioned on each beam spring  34  to read a magnetized wheel  82 . Magnetized wheel  82  may be wheel  30  comprised of a magnetic material, or wheel  30  may otherwise have a magnetic strip  84  applied or embedded ( FIG. 2 ). The electro-magnetic sensor detects whether a rotation is clockwise or counterclockwise. Using direction as a supplemental argument to position effectively doubles the possible combination permutations. In the instant case, the permutations would be 24×24×24, or 13,824. The electro-magnetic sensor  81  may be a Weigand sensor  83  ( FIG. 9 ), or any comparable sensor detecting direction of rotation. 
     A unique setting of dials  40  will correspond to an alignment of apertures  31 . A specific alignment  32  corresponds to preferred orientations  41 , as shown in  FIG. 1 . Preferred orientations  41  demonstrate the visual pattern  43  of dials  40 . Referring to  FIGS. 4 and 5 , visual pattern  43  may present as a array of physical feature  44  on each of the dials, such as the indicator notch  46 . Indicia plate  11 , having indicia markings  14 , may be used as a guide in setting the preferred orientation  41 . An alternate embodiment of visual pattern  43  is shown in  FIG. 5 , where notches  46  display a unique set of colors  45  from a spectrum of color mounted on a facing surface behind. Referring to  FIG. 7 , preferred orientations  41  can be customized by removing dials  40  from shafts  20  and repositioning them to correspond to a preferred pattern. The combination thus selected can be made permanent by bonding the outermost dial to in the innermost shaft, or otherwise fixing it thereto by known means, such as with a fastener. 
     Turning to  FIG. 9 , a means for controlling  70  is represented by microcontroller  71 . Microcontroller  71  receives direction information  85  from Weigand sensors  83  and processes it as stored information  73  in EPROM memory  75  according to logic process  72  ( FIG. 10 ). Microcontroller  71  also receives light information  61  from photo diode  62  and issues a command  75 , following the logic process  72 , to unlock lock  2 . Command  75  may be an RF signal, or other appropriate notice means. 
       FIG. 10  illustrates logic process  72 . First decision  76  compares directional information  85  from a current instance to a saved initial instance. If there is a match, the event is passed as stored information  73 ; otherwise, it is discarded. Second decision  77  determines that there is a light event from light information  61  and passes this to third decision  78 . Third decision  78  determines that there is match to a complete set of current directional instances in stored information  73 . If there is a match, decision  78  issues command  75 . Whether a match or a mismatch, decision  78  dumps all current event information and requires a start over. 
     In the preferred embodiment, shafts  20  are comprised of extruded aluminum and fabricated by machining. Any non-ferrous metal material and any suitable fabrication process would suffice as an alternative. For cost reasons, chassis assembly  10 , wheels  30  and dials  40  are preferably injection molded. Aluminum fabrication for all components, however, except possibly in the case of the wheels where magnetization is required, would represent a more robust construction. The resins of choice would be ABS, Santoprene, or any polymer of comparable toughness and strength. In the preferred embodiment, a magnetic material would be molded as a fill material for wheels  30 . Alternatively, magnetic strips could be insert-molded, or otherwise applied as appliques. Further, insert molding could be used to embed conduction paths for the light and sensors, thereby avoiding wiring or other circuitry. 
     While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. For example, a visual pattern of polarized lighting could be used for a means for indicating. Accordingly, it is not intended that the invention be limited, except as by the appended claims. 
     The light source and sensor are hooded, requiring the source to come only from the transmitter. This helps prevent opening the lock with ‘light flooding’. Also, a specific frequency of light and tuned sensor (IR, Near IR) can be used on a ‘trade secret’ basis

Technology Classification (CPC): 8