Abstract:
An assembly including a cylinder lock including a rotatable member for actuating an external locking element, and a reduction gear disposed inside the cylinder lock, the reduction gear mechanically linked to the rotatable member and operable to rotate the rotatable member, the reduction gear including an interface member for connection to an actuator for movement of the reduction gear.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to gear assemblies and locking apparatus generally, and more particularly to a compact gear assembly, which among other uses, may fit in a plug bore in a cylinder lock for electromechanical operation of the cylinder lock. 
       BACKGROUND OF THE INVENTION 
       [0002]    As is well known in the art, there are many electromechanical cylinder locks operated by an electric motor that turns a locking element in a motor-driven cylinder lock. 
         [0003]    Known prior art systems use motors that require a reduction in rotational speed to operate the motor-driven cylinder lock. The known reduction gears are large and must be located outside the cylinder lock. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention seeks to provide a novel compact gear assembly, typically used as a reduction gear, which among other uses, may fit in a plug bore in a cylinder lock for electromechanical operation of the cylinder lock, as is described more in detail hereinbelow. Thus, in one of its uses, the gear assembly resides in the cylinder lock. 
         [0005]    There is thus provided in accordance with an embodiment of the present invention an assembly including a cylinder lock including a rotatable member for actuating an external locking element, and a reduction gear disposed inside the cylinder lock, the reduction gear mechanically linked to the rotatable member and operable to rotate the rotatable member, the reduction gear including an interface member for connection to an actuator for movement of the reduction gear. 
         [0006]    Non-limiting embodiments of the invention include one or more of the following features. 
         [0007]    The reduction gear includes an inner gear and an outer gear, the outer gear arranged for rotation about a rotation axis. 
         [0008]    The rotatable member and the reduction gear are both arranged for rotation about the rotation axis. 
         [0009]    The inner gear is arranged for translational movement, wherein during translational movement of the inner gear, the inner gear meshes with the outer gear and causes the outer gear to rotate about the rotation axis. The inner gear does not rotate. 
         [0010]    The inner gear is mounted on a shaft that includes an eccentric member which is eccentric to the rotation axis, and during rotation of the shaft about the rotation axis, the eccentric member causes the inner gear to move in the translational movement. 
         [0011]    A limiter constrains the translational movement of the inner gear within defined limits, the limiter not extending beyond outer teeth of the inner gear. The limiter is a straight-sided member that extends axially from the inner gear, the limiter being arranged for movement in an inner periphery of a first boundary member. An outer perimeter of the first boundary member is straight-sided, and the first boundary member is arranged for movement in an inner periphery of a second boundary member, and the first and second boundary members are mounted on the shaft. 
         [0012]    Alternatively, there may be an embodiment wherein the inner gear rotates about the rotation axis. 
         [0013]    There is also provided in accordance with an embodiment of the present invention a gear assembly including an inner gear and an outer gear, the outer gear arranged for rotation about a rotation axis and the inner gear arranged for translational movement, wherein during translational movement of the inner gear, the inner gear meshes with the outer gear and causes the outer gear to rotate about the rotation axis, and a limiter that constrains the translational movement of the inner gear within defined limits, the limiter not extending beyond outer teeth of the inner gear. 
         [0014]    There is also provided in accordance with an embodiment of the present invention a gear assembly including an inner gear and an outer gear, the inner gear arranged for rotation about a rotation axis and the outer gear arranged for translational movement, wherein during translational movement of the outer gear, the outer gear meshes with the inner gear and causes the inner gear to rotate about the rotation axis. This embodiment may be used for increasing the input rotational speed instead of reducing the input speed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: 
           [0016]      FIG. 1  is a simplified pictorial illustration of a reduction gear, constructed and operative in accordance with an embodiment of the present invention; 
           [0017]      FIG. 2  is a simplified side view of the reduction gear of  FIG. 1 ;  FIG. 2A  is a simplified sectional view of the reduction gear of  FIG. 2 , taken along lines A-A in  FIG. 2 ; 
           [0018]      FIG. 2B  is a simplified sectional view of the reduction gear of  FIG. 2 , taken along lines B-B in  FIG. 2A ; 
           [0019]      FIG. 2C  is a simplified sectional view of the reduction gear of  FIG. 2 , taken along lines C-C in  FIG. 2A ; 
           [0020]      FIGS. 3A-3F  are simplified illustrations of the inner gear of the reduction gear translating and causing rotation of the outer gear, in accordance with an embodiment of the present invention; 
           [0021]      FIG. 4  is a simplified pictorial illustration of a gear assembly, constructed and operative in accordance with another embodiment of the present invention; 
           [0022]      FIG. 5  is a simplified side sectional view of the gear assembly of  FIG. 4 ; 
           [0023]      FIG. 5A  is a simplified sectional view of the gear assembly of  FIG. 5 , taken along lines A-A in  FIG. 5 ; and 
           [0024]      FIGS. 6A and 6B  are simplified pictorial and exploded illustrations of a cylinder lock, constructed and operative in accordance with an embodiment of the present invention, wherein a reduction gear is inside the cylinder lock. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0025]    Reference is now made to  FIGS. 1-2C , which illustrates a reduction gear  10 , constructed and operative in accordance with a non-limiting embodiment of the present invention. 
         [0026]    In the illustrated embodiment, reduction gear  10  includes an inner gear  12  and an outer gear  14 . Outer gear  14  is arranged for rotation about a rotation axis  16 . Outer gear  14  is journaled in a housing  18  and has an output shaft  20  that extends outwards from housing  18 . The bearing surface is preferably the output shaft  20  rotating in a hole  21  formed in housing  18  (with optional bearing elements or lubrication material, for example) or the outer contour of the outer gear  14  rotating in housing  18  (with optional bearing elements or lubrication material, for example). 
         [0027]    Inner and outer gears  12  and  14  are mounted on a shaft  22 , which rotates about rotation axis  16 . However, in contrast to outer gear  14 , inner gear  12  is arranged for translational movement and does not rotate. Shaft  22  includes an eccentric member  24  which is eccentric to rotation axis  16  (eccentricity E shown in  FIG. 2A ). During rotation of shaft  22  about rotation axis  16 , eccentric member  24  causes inner gear  12  to move in the translational movement. During its translational movement, inner gear  12  meshes with outer gear  14  and causes outer gear  14  to rotate about rotation axis  16 , as will be explained more in detail below. 
         [0028]    A limiter  26  is provided that constrains the translational movement of inner gear  12  within defined limits. The limiter  26  does not extend beyond the outer teeth of inner gear  12 , which is one of the reasons reduction gear  10  is such a compact assembly. 
         [0029]    In the illustrated embodiment, limiter  26  is a straight-sided member that extends axially from inner gear  12 . Limiter  26  is shown as having four sides, which is considered an optimal number, but the invention is not in any way limited to this configuration. Limiter  26  and inner gear  12  have a common through hole  28  for mounting on shaft  22 . Through hole  28  is large enough to accommodate the movement of eccentric member  24 , and is thus oversized compared to the outer diameter of the shaft  22 . 
         [0030]    Limiter  26  is arranged for movement in an inner periphery of a first boundary member  30 . First boundary member  30  has straight-sided inner and outer contours. The inner contour accommodates the shape of limiter  26  but is larger than the outer contour of limiter  26  to allow for linear movement of limiter  26  therein. 
         [0031]    First boundary member  30  is arranged for movement in an inner periphery of a second boundary member  32 . First and second boundary members  30  and  32  are mounted on shaft  22  as well. As seen best in  FIG. 2A , shaft  22  is journaled in a mounting hole  34  formed in second boundary member  32  (with optional bearing elements or lubrication material, for example). The portion of shaft  22  that extends outwards of second boundary member  32  is an interface member for connection to an actuator (e.g., a servomotor and the like, not shown) for movement of the reduction gear  10 . 
         [0032]    A counterweight  36  may be mounted on shaft  22  for balancing with the eccentric member  24 . 
         [0033]    Reference is now made to  FIGS. 3A-3F , which illustrate inner gear  12  translating and causing rotation of outer gear  14 , in accordance with an embodiment of the present invention. 
         [0034]    The reference axes are X 0  and Y 0 . The Cartesian position of inner gear  12  is shown as coordinates X 0  and Y 0 . The vector showing the angular position of outer gear  14  is designated as Y 2 . 
         [0035]    Initially, as seen in  FIG. 3A , inner gear  12  is positioned relative to outer gear  14  such that the upper teeth mesh. The initial position of inner gear  12  is designated  12 . 1  and initial position of outer gear  14  is designated  14 . 1 . 
         [0036]    In  FIG. 3B , inner gear  12  translates to the right and downwards to position  12 . 2  (by rotation of the eccentric member, not shown here for simplicity). This causes the uppermost teeth of inner gear  12  to move out of outer gear  14  and the right teeth to mesh with outer gear  14 . This causes outer gear  14  to rotate clockwise to position  14 . 2 . 
         [0037]    In  FIG. 3C , inner gear  12  translates to the left and downwards to position  12 . 3 . This causes the right teeth of inner gear  12  to move out of outer gear  14  and the lower teeth to mesh with outer gear  14 . This causes outer gear  14  to further rotate clockwise to position  14 . 3 . 
         [0038]    In  FIG. 3D , inner gear  12  translates to the left and upwards to position  12 . 4 . This causes the lower teeth of inner gear  12  to move out of outer gear  14  and the lower left teeth to mesh with outer gear  14 . This causes outer gear  14  to further rotate clockwise to position  14 . 4 . 
         [0039]    In  FIG. 3E , inner gear  12  translates to the left and upwards to position  12 . 5 . This causes the lower left teeth of inner gear  12  to move out of outer gear  14  and the more upper left teeth to mesh with outer gear  14 . This causes outer gear  14  to further rotate clockwise to position  14 . 5 . 
         [0040]    In  FIG. 3F , inner gear  12  translates to the right and upwards to position  12 . 4 . This causes the left teeth of inner gear  12  to move out of outer gear  14  and the upper teeth to mesh with outer gear  14 . This causes outer gear  14  to further rotate clockwise to position  14 . 6 . The cycle then repeats itself. 
         [0041]    It is noted that reduction gear  10  allows for a very robust construction of the gear teeth. The teeth do not need to be involute; rather the teeth of the inner and outer gears can be straight-sided, with robust thickness. This provides superior strength, significantly reduced bending and contact stresses on the teeth, and increased lifetime. The meshing speed of the teeth is slow because it is governed by the radius of the eccentric member and not by the radius of the inner gear. 
         [0042]    Reference is now made to  FIGS. 4-5A , which illustrate a gear assembly  40 , constructed and operative in accordance with another non-limiting embodiment of the present invention. The elements of gear assembly  40  are similar to those of reduction gear  10 , but in this embodiment the roles are reversed: the outer gear translates and rotates the inner gear. 
         [0043]    In the illustrated embodiment, gear assembly  40  includes an inner gear  42  and an outer gear  44 . Inner gear  42  is arranged for rotation about a rotation axis  46 . Inner gear  42  is journaled in a housing  48  and has an output shaft  50  that extends outwards from housing  48 . A rotating member  51  has a shaft  52 , which rotates about rotation axis  46 . Shaft  52  includes an eccentric member  54  which is eccentric to rotation axis  46  (eccentricity E′ shown in  FIG. 4 ). There may be a counterweight  66 . 
         [0044]    A limiter  56  is provided that constrains the translational movement of outer gear  44  within defined limits. In the illustrated embodiment, limiter  56  is a straight-sided member that extends axially from outer gear  44 . Limiter  56  is arranged for movement in an inner periphery of a first boundary member  60 . First boundary member  60  is arranged for movement in an inner periphery of a second boundary member  62 . During rotation of shaft  52  about rotation axis  46 , eccentric member  54  moves against a hub  63  of first boundary member  60  and causes outer gear  44  to move in the translational movement. During its translational movement, outer gear  44  meshes with inner gear  42  and causes inner gear  42  to rotate about rotation axis  46 , in a manner similar to that explained above for reduction gear  10 . 
         [0045]    Reference is now made to  FIGS. 6A-6B , which illustrate a cylinder lock  100 , constructed and operative in accordance with an embodiment of the present invention, wherein reduction gear  10  is inside the cylinder lock  100 . 
         [0046]    Cylinder lock  100  is shown as a double cylinder lock with a European profile. More specifically, the illustrated embodiment is a motor-driven cylinder lock, driven by motor  101 , which is in-line with a key-operated cylinder lock  103  and they both actuate a common external locking element (i.e., external to the cylinder), typically a centrally located rotatable cam  102 . The motor-driven cylinder lock is typically on the inside of the door and may be operated by an authorized person, such as by means of a transponder in a key which activates motor  101  (such as by RFID) or by a biometric sensor that senses a biometric parameter of the authorized person (e.g., fingerprints and the like) and operates motor  101 . The outer cylinder lock  103  is key-operated, and can be designed as a mechanical override for use under certain conditions. 
         [0047]    However, the invention is not limited to this configuration and can also be carried out for a single cylinder lock and for any kind of profile. 
         [0048]    In the illustrated embodiment, on the right side of  FIG. 6B , it is seen that housing  18  is journaled inside a plug bore  104  of cylinder lock  100 . The output shaft  20  of outer gear  14  is dimensioned to interface directly or indirectly with the cam  102 . The reduction gear can be a single stage reduction gear, comprising the elements on the right side of  FIG. 6B . 
         [0049]    An alternate embodiment is shown in  FIG. 6B , which is a double stage reduction gear. In this embodiment, another set of inner and outer gears is provided. The two stages cooperate as follows. The first boundary member  30  of the right-side stage is arranged for movement in the second boundary member  32 , as described above. The second boundary member  32  is part of a housing  18 ′ which is the housing for the left-side stage (the stage that connects to the motor). The output shaft of the left-side-stage outer gear  14  is designated  22 ′ and it serves as the shaft  22 ′ with eccentric member  24 ′ for the right-side-stage inner gear  12  and outer gear  14 . 
         [0050]    The shaft  22  of the left-side stage may be journaled in a bushing  106  and end cap  108  for interfacing with the shaft of motor  101 . 
         [0051]    Optionally, the reduction gear in the cylinder lock can be of the type wherein both the inner and outer gears rotate, such as but not limited to, harmonic drive reduction gears or planetary-friction type speed change devices that have a plurality of planetary rolling elements disposed between a sun roller and an outer ring, such as described in U.S. Pat. 5,423,725, the disclosure of which is incorporated herein by reference.