Abstract:
A lock system for a door. The lock system includes a clutch mechanism and a lockset with a lockable latch and actuator for operating the latch. The clutch mechanism includes an input cam, an output cam, and an engagement pin having an axis and being dimensioned and configured for axial movement between a first position, in which the engagement pin engages both the input and output cams so that the input and output cams rotate synchronously, and a second position, which allows independent rotational movement of the input cam and the output cam.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to door mounted security systems and, more particularly, to a lock system that can be employed with entry control devices to control access through a door. 
   BACKGROUND OF THE INVENTION 
   Entry control devices are generally mounted on a door and/or a doorframe and operate to limit access through the door. Some conventional entry control devices include a clutch mechanism that selectively couples a bolt and a handle in response to an electronic input, which may be provided by a keypad, a contact activatable chip, a card reader, and other similar input devices. In some cases, entry control devices, and particularly electronically controlled entry devices, are inoperable during power failures and/or when dedicated power sources fail. Additionally, when electrical power is unavailable, conventional electronically controlled entry control devices generally remain in a locked position, restricting access through the door. 
   SUMMARY OF THE INVENTION 
   The present invention provides a lock system for securing a door and a doorframe. In one construction, the lock system includes a clutch mechanism and a lockset with a lockable latch and an actuator for operating the latch. The clutch mechanism includes an input cam, an output cam, and an engagement pin that is dimensioned and configured for axial movement between first and second positions. In the first position, the engagement pin engages both the input and the output cams to couple the input and output cams so that they rotate synchronously, allowing the door to be opened. In the second position, the engagement pin does not engage both the cams and thereby allows independent rotational movement of the input cam and the output cam so that pivoting of the exterior latch lever does not retract the latch. 
   In other constructions, an arcuate carriage cooperates with the engagement pin to move the engagement pin between the first position and the second position. A frame biases the carriage towards a third position, in which the frame maintains the engagement pin in the first position. A removable interchangeable core, when installed, blocks the frame moving the carriage toward the third position. The core, when removed, allows the frame to move the carriage toward the third position, resulting in movement of the engagement pin toward the first position and permitting retraction of the latch. 
   Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is further described with reference to the accompanying drawings, which show constructions of the present invention. However, it should be noted that the invention as disclosed in the accompanying drawings is illustrated by way of example only. The various elements and combinations of elements described below and illustrated in the drawings can be arranged and organized differently to result in constructions which are still within the spirit and scope of the present invention. 
     In the drawings, wherein like reference numerals indicate like parts: 
       FIG. 1  is a perspective view of a first construction of a lock system embodying aspects of the present invention. 
       FIG. 2  is a perspective view of the back side of the lock system shown in  FIG. 1  with the outer housing removed and the lock system in a locked position. 
       FIG. 3  is a perspective view of the back side of the lock system shown in  FIG. 1  with the outer housing removed and the lock system in an unlocked position. 
       FIG. 4  is a perspective view of the back side of the lock system shown in  FIG. 1  with the outer housing removed and a lock core removed from the lock system. 
       FIG. 5  is a perspective view of a second construction of the lock system of the present invention. 
       FIG. 6  is a perspective view of the lock system shown in  FIG. 5  with the outer housing removed and the lock system in a locked position. 
       FIG. 7  is a perspective view of the lock system shown in  FIG. 5  with the outer housing removed and the lock system in an unlocked position. 
       FIG. 8  is a perspective view of the lock system shown in  FIG. 5  with the outer housing removed and a lock core removed from the lock system. 
   

   DETAILED DESCRIPTION 
   The terms “first”, “second”, “upward”, “downward”, “horizontal”, and “vertical” are used herein and in the appended claims for description only and are not intended to imply any particular orientation, order, or importance. 
     FIGS. 1–4  illustrate a lock system  10  according to a first construction of the present invention. The lock system  10  is mountable on an exterior side of a door (not shown) and is operable to limit access through the door and the associated doorframe (not shown). Also, in some constructions (not shown), the lock system  10  can be hardwired. 
   As described in greater detail below, the lock system  10  includes an electronically operated clutch mechanism having an override assembly. In some constructions of the present invention, some of the elements of the lock system  10  function in a manner that is similar to the apparatuses described in U.S. Pat. No. 6,286,347, issued Sep. 11, 2001, entitled “CLUTCH MECHANISM WITH MOVEABLE INJECTOR RETAINER WALL FOR DOOR LOCK SYSTEM” and U.S. Pat. No. 5,640,863, issued Jun. 24, 1997, entitled “CLUTCH MECHANISM FOR DOOR LOCK SYSTEM that are hereby incorporated by reference. Additionally, persons of ordinary skill in the art will recognize the advantages inherent in clutch operated mechanisms, which can operate in combination with lever handles that comply with the regulatory requirements of the Americans with Disabilities Act. 
   As shown in  FIGS. 1–4 , the lock system  10  includes an interchangeable core  12  (e.g., a Schlage™ interchangeable core cylinder, a Best-type interchangeable core, and like the like), a lever handle  14 , a faceplate or cover  15 , and a base plate  16 . As shown in  FIGS. 1–3 , the core  12  is mounted in a recess  17  that extends through the bottom edges of the cover  15  and the base plate  16 . The interchangeable core  12  is removable (as shown in  FIG. 4 ) so that the lock system  10  can be upgraded and/or re-keyed as needed, thereby eliminating the need to re-pin the lock system  10 . To replace the core  12 , a control key (not shown) is inserted through a keyway (not shown), which extends through a front face of the core  12 . The core  12  is then withdrawn from the recess  17  and a new core  12  is inserted into the recess  17 . 
   The handle  14  is coupled to an input cam  18 , which extends through the cover  15  and defines a first axis A. Together, the handle  14  and the input cam  18  are pivotable about the first axis A. An output cam  20  is arranged on an interior side of the cover  15  and is coupled to lockset  21 . The output cam  20  defines a second axis B and includes an engagement pin or shaft  22  having an arcuately shaped head  24 . Together, the input and output cams  18 ,  20  operate as a clutch, providing selective operation of the door lock system  10  as described in greater detail below. 
   The engagement pin  22  is moveable along the second axis B between a first or disengaged position (shown in  FIG. 2 ), in which the engagement pin  22  is spaced a distance from the input cam  18 , and a second or engaged position (shown in  FIGS. 3 and 4 ), in which the engagement pin  22  engages the input cam  18 . In the illustrated construction, the second axis B is substantially perpendicular to the first axis A. However, one having ordinary skill in the art will appreciate that in other constructions (not shown) the first and second axes A, B can be arranged differently and may or may not intersect. Additionally, in some constructions, the engagement pin  22  is coupled to the handle  14  to pivot about the first axis A in response to pivoting motion of the handle  14 . 
   As shown in  FIGS. 2–4 , the arcuately shaped head  24  of the engagement pin  22  engages a carriage  27  having an arcuately shaped camming surface  26 . The arcuately shaped camming surface  26  is configured to accommodate pivoting movement of the handle  14  and the input cam  18  about the first axis A. More specifically, the camming surface  26  is configured to remain in operational engagement with the output cam  20  as the input cam  18  and the handle  14  pivot about the first axis A. Additionally, the carriage  27  is moveable in a direction substantially parallel to the illustrated second axis B between a first or upward-most position (shown in  FIG. 2 ) and a second or downward-most position to selectively move the engagement pin  22  along the second axis B. As shown in  FIG. 2 , when the carriage  27  is in the upward-most position, a spring (not shown) biases the engagement pin  22  upwardly along the second axis B away from the input shaft  18 . As shown in  FIGS. 3 and 4 , when the carriage  27  is in the downward-most position, the carriage  27  compresses the spring and forces the engagement pin  22  into mating engagement with the input shaft  18 . 
   As shown in  FIGS. 2–4 , a motor  28  is coupled to the base plate  16  adjacent to the carriage  27 . In the illustrated construction, the motor  28  is a bi-directional DC motor and is powered by batteries  29 . However, one having ordinary skill in the art will appreciate that other motors (e.g., AC motors) can also or alternately be used. Additionally, in other constructions (not shown), the motor  28  can be hardwired through the door. In the illustrated construction, the motor  28  includes a shaft  30 , which is connected to an axially extending spring  32 . The spring  32  engages a drive nut (not shown) coupled to the carriage  27 . The spring  32  acts as a worm gear and meshes with the drive nut. In this manner, rotational motion of the motor  28  is converted into axial motion of the carriage  27  along the second axis B. More particularly, as the motor  28  rotates the shaft  30  in a first direction (e.g., clockwise), the interaction between the spring  32  and the drive nut causes the carriage  27  to move downwardly. Similarly, as the motor  28  rotates the shaft  30  in a second direction (e.g., counterclockwise), the interaction between the spring  32  and the drive nut causes the carriage  27  to move upwardly. Additionally, during normal operation, the drive spring  32  compensates for jamming conditions. 
   As shown in  FIG. 1 , a keypad  34  is arranged on the cover  15 . The keypad  34  is in communication with a controller (not shown) and lights  35 . During normal operation, an authorized operator enters an appropriate access code using the keypad  34 . If the operator enters an unacceptable access code, the signal lights  35  alert the operator that the signal was unacceptable (e.g., the signal lights  35  emit red light). If the operator enters an acceptable access code, a signal is transmitted to the controller and the signal lights  35  acknowledge entry of an acceptable access code (e.g., the signal lights  35  emit green light). The controller then directs the motor  28  to move the carriage  27  from the upward-most position to the downward-most position. As explained above and as shown in  FIGS. 3 and 4 , as the carriage  27  moves toward the downward-most position, the carriage  27  moves the engagement pin  22  from the disengaged position (shown in  FIG. 2 ) toward the engaged position (shown in  FIG. 3 ), operably connecting the handle  14  and the input cam  18  with the output cam  20 . Once the engagement pin  22  is in the engaged position, the input cam  18  and the output cam  20  are in mating engagement and an operator can open the door by pivoting the handle  14  about the first axis A in a conventional manner. 
   The position of the carriage  27  is also controlled by an override pusher or frame  36 . The frame  36  is a generally U-shaped member having a lower generally horizontal leg  38  and an upper generally horizontal leg  40 . The frame  36  is slideably mounted on the interior side of the base plate  16  between mounting tabs  42  for generally vertical sliding movement between a first or neutral position (shown in  FIGS. 2 and 3 ) and a second or override position (shown in  FIG. 4 ). A bias spring  44  is positioned above the upper leg  40  and biases the frame  36  downward toward the override position. As shown in  FIGS. 2 and 3 , the core  12  engages the lower leg  38  and limits the downward sliding movement of the frame  36 . 
   When the core  12  is removed (as shown in  FIG. 4 ), the bias spring  44  forces the frame  36  downward toward the override position. In the override position, the upper leg  40  of the frame  36  contacts the carriage  26 . The upper leg  40  then forces the carriage  27  downward toward the downward-most position (shown in  FIG. 4 ), in which the carriage  27  compresses the engagement pin  22 , operably coupling the input and output cams  18 ,  20 . 
   When electrical power fails and/or when the batteries  29  fail, the motor  28  and/or keypad  34  may be rendered inoperable. However, maintenance personnel and/or emergency workers using a control key can remove the core  12 . As explained above, removal of the core  12  allows the bias spring  44  to push the frame  36  downward toward the override position, effectively unlocking the lock system  10  by forming a direct linkage between the handle  14  and the lockset  21 . Once the direct linkage between the handle  14  and the lockset  21  is established, an operator can open the door by pivoting the handle  14  about the first axis A in a conventional manner. 
     FIGS. 5–8  illustrate an alternate construction of a lock system  50  having an electrically operated clutch mechanism  52 . Additionally, the door lock system  50  is hardwired and, as shown in the figures, is relatively compact. The lock system  50  is substantially similar in concept to the previously described lock system  10 . Therefore, for reasons of clarity and brevity, only differences between the first and second constructions will be described hereafter. 
   As shown in  FIGS. 5–8 , the lock system  50  includes a core  12 , a handle  14  and a base plate  55 . The core  12  includes a keyway  13  and extends through a front face  51  of a generally circular faceplate  53 . The handle  14  is coupled to an input cam  54 , which defines a first axis C. An output cam  56  is coupled to a lockset  57 . Together, the input and output cams  54 , 56  operate as a clutch, providing selective operation of the door lock system  50 , as described below in greater detail. 
   Selective coupling of the input cam  54  and the output cam  56  is achieved by axial positioning of an engagement pin  58 , which includes an arcuately shaped head  60  and defines a second axis D. The engagement pin  58  is moveable along the second axis D between a first or disengaged position (shown in  FIG. 6 ), in which the engagement pin  58  is spaced a distance from the input cam  54 , and a second or engaged position (shown in  FIGS. 7 and 8 ), in which the engagement pin  58  engages the input cam  54 . 
   A carriage  61  includes an arcuately shaped camming surface  62  that accommodates pivoting movement of the handle  14  and the input cam  18  about the first axis C. Accordingly, the axial position of the engagement pin  58  can be controlled throughout the pivoting travel range of the handle  14 . Additionally, the carriage  61  is moveable axially along the interior surface of the base plate  53  between a first or upward-most position (shown in  FIG. 6 ), in which a spring (not shown) biases the engagement pin  58  toward the disengaged position, and a second or downward-most position (shown in  FIGS. 7 and 8 ), in which the carriage  61  moves the engagement pin  58  toward the engaged position. 
   The position of the carriage  61  is at least partially a function of a bias provided by motor (e.g., a bi-directional DC motor)  28  mounted on the base plate  55 . The motor  28  includes a motor shaft (not shown) and a spring shaft  64  that engages a drive pin (not shown), which is coupled to the carriage  61 . More particularly, when the motor  28  rotates the motor shaft in a first direction (e.g., clockwise), the motor  28  moves the carriage  61  toward the upward-most position. Alternatively, when the motor  28  rotates the motor shaft in a second direction (e.g., counterclockwise), the motor  28  moves the carriage  61  toward the downward-most position. 
   The position of the carriage  61  is also at least partially a function of the override pusher  66 . The override pusher  66  is a generally L-shaped body having an upper generally horizontal leg  68 . The override pusher  66  is mounted between mounting tabs  70  for generally vertical sliding movement between a first or neutral position (shown in  FIGS. 6 and 7 ) and a second or override position (shown in  FIG. 8 ). A bias spring  72  urges the override pusher downward (e.g., toward the override position) so that a side arm  74  contacts the core  12 . Thus, the presence of the core  12  limits the downward sliding movement of the override pusher  66  and maintains the override pusher  66  in the neutral position. 
   When the core  12  is removed, as shown in  FIG. 8 , the bias spring  72  forces an override pusher or frame  66  downward toward the override position. The frame  66  then moves the carriage  61  toward the downward-most position, causing the engagement pin  58  to move toward the engaged position, which results in a coupling of the input cam  54  and the output cam  56  (as shown in  FIG. 8 ). 
   Accordingly, during an emergency and/or when the power to the motor  28  is interrupted, an authorized person using a control key can easily remove the core  12 . Removal of the core  12  causes downward movement of the frame  66 , causing movement of the carriage  61 , which effectively unlocks the mechanism  10  by engaging the handle  14  and the input cam  18  with the output cam  20 . At all other times, the operation of the lock apparatus  50  is unchanged. 
   The terms “core” and “interchangeable core” as used herein refer to a wide spectrum of commercially available locking cylinders operated by control keys that allow replacement of the core of a lock system for re-keying purposes. Thus, as used herein and in the appended claims the terms “core” and “interchangeable core” refer to a wide range of components that may be readily interchangeable in various conventional lock devices. 
   The constructions described above and illustrated in the drawings are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art, that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention as set forth in the appended claims.