Patent Publication Number: US-8523247-B2

Title: Cylinder lock with pivotally-mounted bolt

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a cylinder lock with a pivotally-mounted bolt. 
     As “cylinder lock” it is meant any lock which can receive a lock cylinder for actuation of said bolt. As “lock cylinder”, it is meant a lock mechanism with a housing having a standard profile, such as the europrofile, the British oval profile, or the Swiss profile, and a cylinder with a radially protruding cylinder cam and a key groove, wherein the cylinder can only be rotated within the standard profile with a key inserted into said key groove if said key has a suitable profile for unlocking said lock mechanism, which can be of any suitable type, such as the pin tumbler type, the wafer tumbler type, or the disc tumbler type. 
     As “pivotally-mounted bolt” it is meant a bolt pivotally moveable between a retracted position and an extended position. Such a pivotally-mounted bolt has advantages over a translating bolt, such as a potentially bigger cross-section, and thus greater resistance to breakage and a longer reach by reduced space. Moreover, such a pivotally-mounted bolt can take the form of a hooked bolt, which, in said locking position, prevents that the lock and the striker plate receiving the bolt opposite to the lock be forced apart. 
     European patent EP 940 532 B1 illustrates such a cylinder lock, comprising: 
     a housing with an opening for receiving a lock cylinder with a radially protruding cam; 
     a bolt pivotally moveable between an retracted position and an extended position with respect to said housing; 
     a ring comprising a radial opening for engaging said lock cylinder cam, so as to couple said ring and lock cylinder cam, and a toothed arc with a first end adjacent to said radial opening, and a second end; 
     a slider, coupled between said pivotally-mounted bolt and said ring and comprising a toothed rack for engaging said toothed arc and a recess adjacent to a first end of said toothed rack for engaging said lock cylinder cam, wherein said housing presents a guide for guiding said slider between a first position holding the bolt in said retracted position and a second position holding the bolt in said extended position. 
     A drawback of this prior art is that the slider is not reliably retained when the bolt is in its extended position. As a result, the slider forms a vulnerable point in the lock which could potentially be exploited with malicious intent. In this prior art cylinder lock, a number of security measures are proposed to neutralise this vulnerability, notably a movable fulcrum for the pivotally-mounted bolt. However, these security measures are complex and costly, and add additional potential sources of failure. 
     Another drawback of the abovementioned prior art is that the slider is not reliably retained when the bolt is in its retracted position. As a result, the slider may move out of correct engagement with the ring, in particular when the lock is shipped without a lock cylinder. This can then complicate the correct assembly and installation of the lock. It is a first object of the invention to maintain the correct position of the slider when the bolt is extended and/or when the bolt is retracted, so as to ensure the reliability, and security of the cylinder lock. 
     SUMMARY OF THE INVENTION 
     The present invention achieves this object in that said ring comprises a raised flank extending over a second arc of said ring from said second end of the toothed arc, and said slider comprises at least one stop opposable to said raised flank of the ring in at least one of said first or second positions of the slider so that the raised flank prevents the return of the slider towards the other one of said first or second positions. Preferably, at least one stop in the slider comprises a stop opposable to said raised flank of the ring in said second position of the slider so that the raised flank prevents the return of the slider towards the first position. Thus, if the lock cylinder is turned until the toothed arc displaces the slider to said second position, the raised flank of the ring comes into a position where it is opposed to the stop of the slider, thus preventing a return of the slider towards the first position. The ring can be turned further over the whole second arc and still retain the slider in said second position. 
     It is a further object of the present invention to ensure the reliability, and ease of installation of the cylinder lock. 
     For this purpose, said at least one stop in the slider may comprise a flank of said recess opposable to said raised flank of the ring in said first position of the slider so that the raised flank prevents the return of the slider towards the second position. 
     Preferably, said at least one guide comprises at least one end stop. The guide thus prevents movement of the slider beyond said first and/or second positions. Preferably the guide comprises two end stops, one for preventing movement of the slider beyond its first position and a second one for preventing movement of the slider beyond its second position. Alternatively, or additionally, one or the two end stops may be provided in a further guide for the slider. 
     It is a further object of the present invention to provide a simplified kinematic connection between the slider and the bolt. For this purpose, said slider may present a cam for engaging a recess on said bolt so as to pivot said bolt between said retracted and extended positions. More advantageously, the bolt, in its extended position, may contact said slider cam at a substantial angle to said slider guide. With this self-locking configuration, it will not be possible to move the slider along the guide by forcing the bolt towards its retracted position. Also more advantageously, the bolt, in its extended position, may contact said slider cam at a substantial angle to said slider guide. With this self-locking configuration, it will not be possible to move the slider along the guide by forcing the bolt towards its extended position. 
     A further drawback of the abovementioned prior art cylinder lock is that, when installed in a gate, the lock may be forced apart from an opposite strike plate by deforming the gate, thus driving the bolt out of the strike plate and unlocking the gate. 
     It is a further object of the present invention to provide a lock whose extended bolt will resist attempts to force the lock apart from a strike plate engaged by the extended bolt. For this purpose, the bolt may be hook-shaped. 
     It is a further object of the present invention to provide haptic feedback to the user of the lock when the slider reaches said first and/or second position. For this purpose, the cylinder lock may also comprise a detent mechanism for marking said first and/or or second position of the slider. Preferably, said detent mechanism may comprise a spring-loaded detent member fixed to one of said slider or housing, and at least one recess in the other of said slider or housing for receiving said spring-loaded detent member when the slider is in said first and/or second position. 
     Preferably, the cylinder lock may also comprise a latch spring-loaded towards an extended position. Furthermore, said latch may also be coupled to said lock cylinder cam, so as to be retractable against said spring load by rotation of said lock cylinder cam. Also, said latch may also be coupled to a handle, so as to be retractable against said spring load by rotation of said handle. 
     The present invention also relates to a cylinder lock according to the invention further comprising a lock cylinder in said opening, and to a gate comprising a fixed frame with a strike plate and a movable closure element with a cylinder lock according to the invention, wherein the bolt of the cylinder lock is aligned with said strike plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Particular embodiments of the invention will now be described in an illustrative, but not restrictive form, with reference to the following figures: 
         FIG. 1  shows a perspective view of an embodiment of a cylinder lock according to the invention; 
         FIG. 2  shows another perspective view of the cylinder lock of  FIG. 1 , installed within a door, and receiving a conventional europrofile lock cylinder; 
         FIGS. 3   a - 3   h  are a sequence of a cutaway side views of the cylinder lock of  FIG. 1  with a lock cylinder installed, with the bolt going from its retracted to its extended position; 
         FIGS. 4   a - 4   c  are detail perspective views of the set of ring and slider of the same cylinder lock in the retracted bolt position illustrated in  FIG. 3   a;    
         FIGS. 5   a - 5   c  are detail perspective views of the set of ring and slider of the same cylinder lock in the extended bolt position illustrated in  FIG. 3   h;    
         FIG. 6   a  and  FIG. 6   b  are perspective views of the same cylinder lock in, respectively, the retracted position illustrated in  FIG. 3   a  and the extended position illustrated in  FIG. 3   h;    
         FIG. 6   c  is a detail view of a detent mechanism of the same cylinder lock; and 
         FIG. 7  is a cutaway side view of the cylinder lock of  FIG. 1 , with both bolt and latch retracted. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning to  FIG. 1 , the illustrated cylinder lock  1  according to a preferred embodiment of the invention is shown in the form in which it is usually shipped, that is, without lock cylinder or handle and with the bolt  2  in a retracted position. The cylinder lock  1  comprises a bolt  2  mounted pivotally on a fulcrum  3 , a latch  4  spring-biased towards the illustrated extended position, a shaft  5  for driving said latch  4  against its extension bias, and a housing  6  presenting an opening  7  for receiving a europrofile lock cylinder, guides  8 ,  9  and a front plate  10 . 
       FIG. 2  shows the same cylinder lock  1  installed in a gate  11 , with a lock cylinder  12  mounted in said opening  7 , a handle  13  fixed to said shaft  5 , and a cover plate  14 . The bolt  2  is shown here in its extended position, in which its hook shape, pointing towards its deployment direction, becomes apparent. 
     The inside of the housing  6  is visible in  FIG. 3   a . A ring  15  is mounted around the lock cylinder  12 . Said ring  15  presents a radial opening  16  for allowing the passage of the lock cylinder  12 , and also for engaging the lock cylinder cam  17 . Opposite to said radial opening  16 , the ring  15  of the illustrated embodiment presents a centering notch  39  which cooperates with a resilient member  40  in the lock  1  to locate the ring  15  in a default position in which the radial opening  16  of the ring is aligned with the opening  7  in the housing  6 , so that the lock cylinder  12  can be installed and/or extracted. 
     The ring  15  also comprises a toothed arc  18  and a raised flank  19  over a second arc. The lock  1  also comprises a slider  20 , in engagement with the abovementioned guiding grooves  8 ,  9  and an opposite, parallel guide  21 . The guides  8 ,  9  and  21  are preferably linear. This slider  20  comprises a toothed rack  22 , a recess  23 , a blind hole  24 , and a cam  25  protruding substantially perpendicularly to said guides  8 ,  9  and  21 . Said cam  25  contacts the bolt  2  behind said fulcrum  3 , seen from the front plate  10  of the lock. 
     Furthermore, the lock  1  also comprises a compression coil spring  26  biasing said latch  4  towards its extended position and an arm  27  coupled to said shaft  5  and an auxiliary slider  28  for retracting said latch  4 . 
     In  FIG. 3   a , the bolt  2  is illustrated in its retracted position. In this position of the bolt  2 , the slider  20  is in a first, lower position in which its cam  25  contacts the bolt  2  substantially perpendicularly to said guides  8 ,  9 ,  21 . 
       FIGS. 3   b - 3   h  illustrate the process of deploying the bolt  2  from its retracted position illustrated in  FIG. 3   a . As shown in  FIG. 3   b , as the cylinder cam  17  is rotated counter-clockwise from the position of  FIG. 3   a , it comes to engage the recess  23  in the slider  20 , pushing said slider  20  upwards. As shown in  FIG. 3   c , the slider cam  25  engages a recess  29  in the bolt  2 . In  FIG. 3   d  it is shown how, after the cylinder cam  17 , the toothed arc  18  comes to engage the slider  20 , and namely its toothed rack  22 , to continue displacing the slider  20  upwards once the cylinder cam  17  rotates out of engagement with the recess  23  in the slider  20 , as illustrated in  FIG. 3   e . In  FIGS. 3   f  and  3   g  it is shown how, as the cylinder cam  17  and the ring  15  continue their counter-clockwise rotation, subsequent teeth of the toothed arc  18  engage the toothed rack  22  to continue the upwards motion of the slider  20 . Over this whole motion, the slider cam  25  remains in engagement with the bolt recess  29 , tilting the bolt  2  towards its extended position, shown in  FIG. 3   h . In this extended position of the bolt  2 , the slider  20  is in a second, higher position in which the slider cam  25  no longer engages the bolt recess  29 , but instead contacts the bolt  2  substantially perpendicularly to the guides  8 ,  9 ,  21 . 
     As in both the retracted and the extended positions of the bolt  2  the contact between the slider cam  25  and the bolt  2  is substantially perpendicular to the slider guides  8 ,  9 ,  21 , and thus self-locking, trying to force the bolt  2  from outside the lock  1  will normally not displace the slider  20  in the direction of its guides  8 ,  9 ,  21 . However, the raised flank  19  of the ring  15  further ensures the correct positioning of the slider  20  in the corresponding first and second positions, as illustrated in  FIGS. 4   a - 4   c  and  5   a - 5   c.    
     In  FIGS. 4   a - 4   c , the ring  15  and slider  20  are depicted in the first, lower position of the slider  20 , corresponding to the retracted position of the bolt  2 , as seen from three different viewpoints. As can be seen in  FIG. 4   a , the slider  20  comprises protrusions  32  and  33  on one side, for engaging, respectively, guides  8  and  9 , and pin  34  on the other side for engaging guide  21 . The slider is thus only movable in the axis of those guides  8 ,  9  and  21 . In this first position, the raised flank  19  of the ring  15  opposes the upper flank of the recess  23 , locking the slider  20  into this first, lower position even as the ring  15  is rotated over said second arc. As can be seen in particular in  FIG. 4   c , the raised flank  19  threads within the groove  30  carved into the slider, so that the ring  15  can be rotated over said second arc. A lower end stop at any of the guides  8 ,  9  or  21  prevents movement of the slider  20  in a downwards direction. 
     In  FIGS. 5   a - 5   c , the ring  15  and slider  20  are depicted in the second, upper position of the slider  20 , corresponding to the extended position of the bolt  2 , as seen from three different viewpoints. As can be seen in particular in  FIGS. 5   b  and  5   c , in this position, the raised flank  19  of the ring  15  opposes a raised stop  31  in the slider  20 , preventing the return of the slider  20  in a downwards direction. Further motion of the slider  20  in an upwards direction may be prevented by an end stop in at least one of the guides  8 ,  9 ,  21 . The slider  20  is thus locked into this second, upper position even as the ring  15  is rotated over said second arc. 
     As illustrated in  FIGS. 6   a - 6   c , in order to further ensure the correct positioning of the slider  20  and also offer a haptic feedback to the user as he turns the key within the lock cylinder  12  to rotate the lock cylinder cam  17 , translate the slider  20  and tilt the bolt  2  between its retracted and extended positions, the lock  1  also comprises a detent mechanism formed by a spring-loaded member  35  within the blind hole  24  of the slider  20 , and two recesses  36 ,  37  in the housing  6 , located so that said spring-loaded member  35  clicks into a first recess  36  when the slider  20  is at his first, lower position, as seen in  FIGS. 6   a  and  6   c , and into a second recess  37  when the slider  20  is at his second, upper position, as seen in  FIG. 6   b.    
     The sequence illustrated in  FIGS. 3   a - 3   h  can be reversed to tilt the bolt  2  from its extended position towards its retracted position by turning the cylinder cam  17  clockwise from the position illustrated in  FIG. 3   h . Turning it clockwise even further from the position of  FIG. 3   a , as shown in  FIG. 7 , the cylinder cam  17  engages the auxiliary slider  28 , driving it upwards. The auxiliary slider  28  in turn drives the arm  27 , retracting the latch  4  against the spring  26 . 
     Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the invention as set forth in the claims. Accordingly, the description and drawings are to be regarded in an illustrative sense rather than a restrictive sense.