Abstract:
A lock with sensor comprises a housing defining a chamber and a latch mechanism located within the chamber of the housing. The latch mechanism is movable relative to the housing between a retracted position wherein the latch mechanism is substantially within the housing and an extended position wherein the latch mechanism extends at least partially outside of the housing. A sensor mechanism is provided and has a fixed switch portion located within the chamber and a movable switch activator portion, the switch activator portion being mounted so as to move with the latch mechanism and thereby activate and deactivate the switch portion respectively.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     This invention relates to locks with sensors, and particularly a lock incorporating sensing and/or switching equipment therein in order to provide signals to an external source relating to the condition of the lock. 
     Locks are, of course, well known and are available in many different forms and configurations. For the most part, however, locks comprise some form of housing which accommodates a reciprocating latch or lever, the latch being movable between an unlocked withdrawn position and a locked extended position. In the withdrawn position, the latch would normally be contained within the housing, while in the extended position, the latch would engage an external and adjacent object to effect the locking operation. The latch would normally be movable between the withdrawn and extended position in response to the rotation of a key in the lock, or rotation of a handle, although such movements may also be in response to electrical, magnetic, pneumatic or other types of mechanical activation. 
     It is also known to provide external sensors with respect to such locks. Conventionally, a sensing switch or other device may be located externally of the lock, in order to sense or determine the position of the lever. The mechanical movement of the lever into the extended position has the effect of activating the sensor in one way to provide signals as to its condition, while the sensor would be activated in another manner to indicate the withdrawn or unlocked position of the lever. 
     It may be important to determine the position of the latch, namely, whether in the extended or retracted position, so that devices or systems can be connected to the lock and react according to the position of the latch. For example, the lock may be connected to an alarm system, such that when the lock is moved from the locked to an unlocked position while the alarm is operational, a signal will be provided to trigger the alarm. The lock may also be connected to video and/or audio recording equipment, heating and cooling systems, lighting systems, computers and/or other recording instruments to collect information on personnel or objects entering or leaving a particular area, especially areas which contain information or products which may be of a classified or confidential nature. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, there is provided a lock with sensor comprising: a housing defining a chamber; a latch retractor located within the chamber of the housing and being movable relative thereto between a retracted position wherein the latch retractor is substantially within the housing and an extended position wherein the latch retractor extends at least partially outside of the housing; and a sensor mechanism having a fixed switch portion located within the chamber and a movable switch activator portion, the switch activator portion being mounted so as to move with the latch retractor and thereby activate and deactivate the switch portion respectively. 
     According to another aspect of the invention, there is provided a method of detecting the position of a latch retractor within a housing of a lock, the latch retractor being movable between a retracted position and an extended position, the method comprising: mounting a switch member at a fixed location within the housing of the lock; mounting a switch actuator member on the latch mechanism within the housing, wherein the switch actuator member operatively engages and activates the switch member in one of the retracted or extended positions, and is remote from the switch; and transmitting signals from the switch member, according to the position of the latch mechanism, to an external source component remote from the lock. 
     The invention provides a lock incorporating a sensing mechanism for detecting the locked or unlocked condition thereof. Preferably, the lock comprises a housing member with a movable latch or lever therein, the latch being movable between an unlocked withdrawn position and a locked extended position, the movement of the latch causing activation or deactivation of a switch member. Preferably, the switch member, upon detecting a change in the condition of the lock, provides a signal to an external component, the component functioning in a predetermined manner according to the condition of the lock. 
     Preferably, the sensing mechanism contained within the lock comprises a fixedly member within the housing, and a movable member which moves with the lever between the extended and the retracted position, such that the orientation of the movable member in relation to the fixed member is able to provide the appropriate signal as to the condition of the lock. The fixed member is conveniently an electric switch, which sends an electric signal to the external component. The movable member may comprise a pin, magnet, projection on the lever, or other physical means which, by virtue of its movement with the lever between the extended and retracted position, has the effect of activating or deactivating the switch. 
     The activation of the switch may cause different results at the external component, depending upon the nature of the external component. For example, when the latch is in the withdrawn position, it may switch off the external component, which may be a surveillance camera; on the other hand, it may switch on the external component, which may be a light. Thus, the movement of the latch and the movable means will have the effect of activating or deactivating the switch, with either one of these conditions being used by the external component according to the type of function it performs. In other words, the component, depending ion its nature, may be switched either on or off when the latch is in the withdrawn position. The lock with sensor of the invention would be used appropriately to activate or deactivate the component, as appropriate, when the latch is withdrawn. 
     The invention has particular application with respect to cylindrical locks, including those using pin tumblers which need to be properly aligned with respect to each other by a key in order to rotate the cylinder. However, the invention is not restricted to such locks, and can be used with any lock mechanism which includes a fixed housing and a movable lever therein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic representation of a lock with sensor of the invention, with the lever in the extended position; 
     FIG. 2 is a schematic representation of the lock with sensor of the invention as shown in FIG. 1, with the lever in the retracted position; 
     FIG. 3 is an exploded perspective view of a first embodiment of a lock of the invention; 
     FIG.  4 ( a ) is a top view of the lock with sensor as shown in FIG. 3, partially in section, with the lever in the extended position; 
     FIG.  4 ( b ) is a side view of the lock with sensor as shown in FIG. 3, partially in section, with the lever in the extended position; 
     FIG.  5 ( a ) is a top view of the lock with sensor as shown in FIG. 3, partially in section, with the lever in the retracted position; 
     FIG.  5 ( b ) is a side view of the lock with sensor as shown in FIG. 3, partially in section, with the lever in the retracted position; 
     FIG. 6 is an exploded perspective view of a second embodiment of a lock of the invention; 
     FIG.  7 ( a ) is a top view of the lock with sensor as shown in FIG. 6, partially in section, with the lever in the extended position; 
     FIG.  7 ( b ) is a side view of the lock with sensor as shown in FIG. 6, partially in section, with the lever in the extended position; 
     FIG.  8 ( a ) is a top view of the lock with sensor as shown in FIG. 6, partially in section, with the lever in the retracted position; 
     FIG.  8 ( b ) is a side view of the lock with sensor as shown in FIG. 6, partially in section, with the lever in the retracted position; 
     FIG. 9 is a side view, partially in section, of the latch mechanism showing the pin hole; 
     FIG. 10 is a side view of the pin member; and 
     FIG. 11 is a top view of the housing showing the slot for the wire. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the drawings, there is shown schematically, as well as in various detailed embodiments, the lock with sensor of the invention. With reference to FIGS. 1 and 2, there is shown in schematic form the essential features which comprise the invention. These Figures show a lock with sensor  10  comprising a housing  12  which defines a space or chamber  14 . The housing  12  has an opening  16  in a side wall  18 . Within the chamber  14 , there is located a latch  20  which is slidable within the housing  12  between an extended position, as shown in FIG. 1 of the drawings, and a retracted position, as shown in FIG.  2 . The lock with sensor  10  would typically be mounted to a door or the like, and align with another object, such as an adjacent door or jamb. The latch  20 , when in the extended position, enters a catch or groove  22 , in conventional fashion. 
     The lock with sensor includes a switch mechanism  24  mounted within the chamber  14 , and in fixed position within the housing. The switch has wiring  26  extending therefrom to a source component  28 , the source component  28  in the drawings being representative of any one of a number of devices, such as a camera, an alarm, lighting system, computer, or the like. The scope of the invention is not limited by the nature of the source component  20  or the function which it is to perform. Rather, the invention is intended to provide an electric or other signal from the switch  24  to any predetermined source component  28  to be used in the desired manner. 
     On the upper surface  30  of the latch  20 , there is located a pin  32  which is fixed to the latch  20 . The pin  32  reciprocates within the chamber  14  as the latch  20  moves between its extended and retracted positions. This is clearly illustrated in FIGS. 1 and 2 of the drawings. When the latch  20  is in the extended position, the pin  32  is remote from the switch  24 . On the other hand, when the latch  20  is withdrawn into its retracted position, the pin  32  comes into contact with the switch  24 , closing the electrical circuit in a conventional manner and changing the nature of the signal transmitted through the wiring  26  to the source component  28 . The reciprocation of the pin  32  therefore has the effect of turning on or off, as desired, the source component  28 . 
     Reference is now made to FIGS. 3 to  5  of the drawings, which show the specific features of the invention in a more detailed embodiment of the invention. With a reference to these Figures, there is shown a lock with sensor  40  comprising a housing base  42  which is releasably attached to a housing  44 , as will described in further detail below. Extending from the housing base  42  is a fixed handle  46 , and on the opposite side of the lock with sensor  40 , and extending outwardly through an aperture  48  in the housing  44 , is a removable handle  50 . In conventional fashion, the handles  46  and  50  can be rotated about their longitudinal axes, represented by line  52 , to move a latch retractor  54  between an extended and retracted position, to be described in further detail below. The rotation of the handles  46  and  50  may only be possible upon insertion of a key (not shown) within the lock, or by first using a key to allow rotation of the handles  46  and  50 . Various permutations as to the ability of these handles  46  and  50  to rotate may be possible, and the invention is not limited to any one configuration. 
     Attached to the housing base  42  there is located an upper internal bracket  56  and a lower internal bracket  58 , which are essentially parallel to each other. Each of the internal brackets  56  and  58  has a pair of jaws  60  and  62  respectively. The jaws  60  pass through the upper slots  64  of the handle  50 , and thereafter engage the upper slots  66  of the housing  44 . The jaws  62  pass through the lower slots  68  of the handle  50 , and engage the lower slots  70  of the housing  44 . In this way, the upper and lower internal brackets  56  and  58  are attached, releasably, to the handle  50  and housing  44 . 
     The housing base  42  and housing  44 , when connected as described above, define a chamber  68  in which the latch mechanism  54  and related components are contained. 
     The lock with sensor  40  further comprises a rotatable cylinder  70 , rotation of which is in response to the rotating of either one of handles  46  or  50 . Rotation of the cylinder  70  has the effect of moving the latch retractor from the extended to the retracted position. The cylinder  70  engages the latch retractor  54 , as best shown in FIGS.  4 ( b ) and  5 ( b ) of the drawings. In FIG.  4 ( b ), the latch is in the extended position, but rotation of the cylinder  70  causes the cylinder  70  to move the latch  54  towards the retracted position. The rotational movement of the cylinder  70  is thus converted to a linear motion of the latch retractor  54 . The cylinder  70  has abutment edges  72  which engage with angled abutment edges  74  of the latch mechanism  54 . The latch retractor  54  is, under normal conditions, biased by springs  76  so that the latch member  54  is urged towards the extended position. When the cylinder  70  moves the latch retractor  54  against the action of the springs  76 , it moves to its retracted position, and its extent of travel is limited by a rear abutment plate  78 . 
     The upper internal bracket  56  is designed so as to receive and hold in a fixed position a switch  80 . The switch  80  comprises a switch housing  82  and an element  84 . The element  84  is comprises of a resilient material which can be moved so that its end  86  is either away from the switch housing  82  or in contact therewith. When the end  86  contacts the switch housing  82 , the circuit is closed, and electrical signals can be transmitted along wires  88  to a source component. The source component is not shown in FIGS. 3 to  5 , but may be any one of a number of devices, for example as discussed with respect to FIGS. 1 and 2. 
     The switch  80  is located within an insulator  90 , the insulator  90  comprising a U-shaped bracket for receiving the switch  80 . Both the switch  80  and insulator  90  have a pair of holes  92  and  94  through which screws  96  may pass. The upper internal bracket  56  has a pair of tapped holes  98 , which are arranged with respect to each other such that the screws  96  pass through the insulator  90 , switch  80 , and are fixed to the upper surface of the internal bracket  56 . 
     The latch retractor  54  has a pin hole  100  for receiving a pin  102 . The pin hole  100  is angled with respect to the horizontal, as best illustrated in FIG.  9 . In one preferred form, the pin hole  100  has an axis which is approximately at 60° to the horizontal. The pin  102  itself comprises a base portion  104  and a projecting portion  106 . The base portion  104  is located in the pin hole  100 , and the projecting portion  106  extends outwardly beyond the upper surface of the latch retractor  54 . 
     As will be appreciated, the pin  102  moves with the latch retractor  54 , so that it reciprocates between a first position when the latch retractor is extended, and a second position when the latch is retracted. This arrangement can be clearly seen by comparing FIGS.  4 ( a ) and  5 ( a ), and FIGS.  4 ( b ) and  5 ( b ). When the latch retractor  54  is in the extended position, the pin  102  moves the end  86  of element  84  so that it comes into contact with the remainder of the switch  80 , closing the electric circuit. This is clearly seen in FIG.  4 ( a ) of the drawings. On the other hand, when the latch retractor  54  is moved into the retracted position, the pin  102 , and particularly the projecting portion  106  thereof, is moved away from the switch  80  such that the element  84 , due to its resilience, moves away from the switch housing  82 , leaving the electric circuit open. Thus, the position of the latch will determine the presence or absence of an electrical signal transmission through the wires  88 , which can be used at the source component in the desired manner. 
     In order to permit the latch retractor  54  to move into the extended position, and project partially to the outside of the housing  44 , the housing  44  includes an opening  106 . The housing  44  will also include appropriate apertures, for example aperture  108 , through which the wires  88  extend from the chamber  68  to the outside of the lock with sensor  40 , for appropriate connection to the source component and such other devices, such as a power source, necessary to make it operational. In FIG. 11 of the drawings, the housing  44  is shown in top view, and the aperture  108 , through which the wires can be threaded from the outside into chamber, is clearly illustrated. 
     It will be noted that the lock with sensor shown in FIGS. 3 to  5  of the drawings includes a sensing mechanism which uses the opening and closing of an electric circuit by means of a mechanical device, in this case a pin, for activating or deactivating the source component. Reference is now made to FIGS. 6 to  8  of the drawings, which shows another embodiment of the invention. 
     In FIGS. 6 to  8  of the invention, the basic components of the lock with sensor are the same as that shown with respect to FIGS. 3 to  5 , and a detailed description of the lock in FIG. 6 will therefore not be provided. However, like reference numerals have been used in FIGS. 6 to  8  for corresponding components and elements as described with respect to FIGS. 3 to  5 . 
     In FIGS. 6 to  8 , an embodiment of the lock with sensor  40  includes a switch  120  within the chamber  68  defined by the housing  44  and housing base  42 . The upper internal bracket  56  has located therein an elongated aperture or slot  122  over which the switch  120  is mounted. This can be clearly seen in FIGS.  7 ( a ) and  8 ( a ) of the drawings. As described with respect to the embodiment of FIG. 3, the switch  120  is mounted on the upper internal bracket  56 , over the slot  122 , and is fixed relative thereto. The switch  120  does not move when in the housing. 
     The latch mechanism  54  has an upper surface  124  having a cylindrical hole  126  bored therein. The cylindrical hole  126  is sized and configured so as to receive a cylindrical shaped magnet  128 . The magnet  128  is completely received within the cylindrical hole  126  so that its upper end  130  is flush with, or slightly below, the upper surface  124  of the latch retractor  54 . The magnet  128  is retained within the cylindrical hole  126  by affixing a cap or lid  132  over the upper surface  124  of the latch mechanism  54 . The cap  132  comprises a cover portion  134  and a connecting portion  136 . The connecting portion  136  has rails  138 , which slidably engage grooves  140  on the latch retractor  54 . When the cap  132  is slid onto the upper surface  124  such that the rails  138  engage within the grooves  140 , the cover portion  134  overlies the magnet  128  located in the cylindrical hole  126  so that it will not fall out. 
     As will be appreciated from the description of the construction of the latch retractor  54  with associated magnet  128 , movement of the latch retractor between the extended and retracted position results in the concomitant reciprocation of the magnet  128 . As best seen in FIGS.  7 ( a ) and  8 ( a ) of the drawings, the magnet moves linearly, so as to be under the slot  122 , and under the switch  120 , when in the retracted position, but, when moved into the extended position, the magnet  128  is no longer located under the slot  122 , and therefore under the switch  120 . The switch  120  is of the type that is activated and deactivated by a magnetic force. The presence of a magnet in close proximity to the switch  120  will close (or open, as the case may be) the electric circuit in the switch  120 . When the magnet is moved away from the switch  120 , the activation (or deactivation) thereof will occur. Therefore, the switch  120  will be in a different condition depending upon the location of the magnet  128 . As such, the movement of the magnet  128  towards or away from the switch will open or close the switch  120  depending upon its position. 
     The cap  132  is comprised of material such that it will not interfere with the ability of the magnet  128  to create a magnetic force on the other side of the cap  132 . Furthermore, the presence of the slot  122  ensures that there is no significant barrier or obstacle to the magnetic force when the latch mechanism is in the retracted position; however, when the latch mechanism  54  is extended to the extended position, the upper internal bracket  56  will create such an obstacle. 
     The switch  120  is connected to a wire  138  which leads from the chamber  68  through a wire slot  140  in the housing  44 . The wire  138  is thereafter connected to a source component and/or power supply as may be necessary, as described above. The wire  138  in the embodiment shown in FIGS. 6 to  8  is surrounded by, or encased within, Teflon® tubing  142 , to provide a protective sheath. 
     As will be appreciated from the description above, the invention provides a lock with an internally located sensing apparatus, with the sensing apparatus contained within the housing and sensing whether the latch retractor is in the retracted or extended position. The sensing apparatus has electric wires leading out from the housing in order that the lock may be connected to a source component which will react to signals received from the sensing apparatus of the lock to carry out a desired function. 
     The invention is not limited to the precise details which are described herein. For example, any mechanical element for activating the switch may be provided. Instead of a pin, the latch may have an appropriately located projection or flange which has the same effect. The switch may be located at any convenient place within the chamber of the lock, relative to the latch mechanism, provided that the switch activator on the latch retractor is, of course, correspondingly located. 
     Further, while a mechanical and magnetic switch activating system has been shown in the embodiments described above, other methods of determining the position of the latch within the housing, and providing a signal to an external source, may be provided. Thus, the sensing mechanism may comprise light beams, fiber optics, pneumatic or mechanical means, any one of which is connected, whether directly or indirectly, to the source component which responds to the position of the latch retractor  54 .