Abstract:
A lock, such as a mortise lock, for a door. The lock comprises a locking cylinder that can be inserted into a door leaf and a shaft having two sections, each section of the shaft having a handle at the end, preferably a rotary knob or a standard door handle and being actively interconnected by a coupling after recognition of an authorisation code. The lock can be used for various applications as a result of its construction design, with a standard locking cylinder in various doors and that it allows, a simple, reliable, low-energy actuation of the locking mechanism. To achieve this, the coupling ( 11 ) comprises at least two, preferably four or more rolling members ( 17 ) that are guided in recesses ( 18 ) of a second part ( 10 ) of a first section ( 5 ) of the shaft ( 3 ). The rolling members can be pushed into cavities ( 20 ) that run around the periphery of the first part ( 9 ) of the first section ( 5 ) of the shaft ( 3 ), in order to actively connect a first part ( 9 ) and the second part ( 10 ) of the first section ( 5 ) of the shaft ( 3 ), using a radially or axially displaceable sliding element ( 22 ).

Description:
BACKGROUND 
   1. Field of the Invention 
   This invention relates to a lock, in particular a mortise lock for a door. Said lock comprises a locking cylinder that can in particular be inserted into a door leaf and a shaft consisting of two sections, each section of said shaft having a handle at the end, preferably a rotary knob or a standard door handle, and being actively interconnected by means of a coupling after recognition of an authorisation code. 
   2. Description of Related Art 
   Locks of this kind are known from prior art. They are built into door leafs particularly in the entrance door area, the opening and closing of the door, i.e. the movement of a catch bolt being accomplished via the shaft. To this end, said shaft includes an outside door handle, in particular a freely rotatable rotary knob that allows the catch bolt to be actuated only upon prior verification of an authorisation code through the locking cylinder. On the inside of the door there is also provided a handle, in particular a rotary knob. But this handle always serves for opening the door, even without verification of the authorisation code for actuation of the catch bolt. This makes sure that a door which is constructed in this way can always be opened from inside a building, whereas access to the building is possible only if an appropriate authorisation code has been entered before, which authorisation code produces the active interconnection between said outside door handle and said catch bolt. Said authorisation code may be entered mechanically or electronically. For example, the authorisation code can be the locking secret of a conventional key. On the other hand, it is possible to communicate the authorisation code via a keyboard or in a wireless fashion, for example through radio communication. 
   From DE 199 16 791 C1 a lock is known which can be designed as a mortise lock for a door. This lock includes a shaft which is subdivided in two sections, each of which having a handle, and the catch bolt of the lock being operable through a section of said shaft. To this end, a coupling is provided in the door outside area, which coupling actively interconnects the outside section of the shaft in said door with the inside section of the shaft in said door after recognition of an authorisation code. However, a considerable drawback can already be recognized here in as much as said coupling is arranged in the region of the outside section of the shaft, so that it may possibly be easily accessed and manipulated. Another drawback of this known lock is that doors of different thickness require the use of locking cylinders of a different length, which locking cylinders are normally penetrated by said shaft. 
   Further known from DE 198 24 713 A1 is a locking cylinder having a housing and a locking member supported for rotation within said housing. Said locking member is connected to a driving shaft that is divided in two sections that can be actively interconnected by means of a coupling. Said coupling is formed as a solenoid and is activated by a control electronic in dependence of an access authorisation. 
   BRIEF SUMMARY OF THE INVENTION 
   Starting from this prior art the invention is based on the problem of developing a lock of this type in such a way that it can be used for various applications as a result of its construction design, in particular with a standard locking cylinder in various doors and that it allows, in particular, a simple, reliable, low-energy actuation of the locking mechanism. 
   The solution of this problem provides that the coupling comprises at least two, preferably four or more rolling members that are guided in recesses of a second part of a first section of the shaft. Said members can be pushed into cavities that run around the periphery of the first part of the first section of the shaft, in order to actively connect a first part and the second part of the first section of the shaft, using a radially or axially movable sliding element. 
   The lock according to the invention stands out due to the coupling including at least two, preferably four or more rolling members that are guided in recesses of the second part of the first section of the shaft, which rolling members are pushed into cavities that run around the periphery of the first part of the first section of the shaft, in order to actively connect the first part and the second part of the first section of the shaft, using a radially or axially movable sliding element. 
   When the sliding element is in its initial position, the rolling members will substantially be in their recesses of the second part of the first section of the shaft. Any active connection between the first part and the second part of the first section of the shaft will not be possible then. When the sliding element is displaced towards the shaft it will push the rolling members into the recesses that run around the periphery of the first part, thereby producing a positive and/or frictional locking between said two parts of the first section of the shaft. This positive and/or frictional locking of the two parts of the first section of the shaft leads to an active interconnection of these two parts of the first section of the shaft, as a result of which the locking pin of the lock can be operated through the outside door handle. 
   Said rolling members are, in particular, formed as balls or rolls. 
   According to a further feature of the invention it is provided that the sliding element is displaceable in the radial direction of the shaft through a knee lever. Such a knee lever offers the advantage that it can be operated with relatively low forces, while producing high forces on the output side. 
   According to a further feature of the invention it is provided that the sliding element is driven by an electric motor including on the output side thereof a worm with a spring guided therein which has two arms and is articulated in said worm by its one arm and to the sliding element by its second arm. This construction offers the advantage that only little energy is required for moving the arm of the spring that is guided in the worm from one end of the worm to the second end of the worm. In addition, the spring compensates tolerances between the movement of the motor and the movement of the sliding element and represents an economical construction. 
   According to a further feature of the invention it is provided that the rolling members are juxtaposed in plural and at least in two rows side by side. With at least two parallel rows of rolling members the advantage is that smooth operation of the two coaxially arranged parts of the first section of the shaft is attained, which also has an effect on the actuation of the coupling. While a number of two rolling members may be always provided in the lock, it would be advantageous to have a number of at least four or for example also six or eight rolling members per row. 
   As an alternative of an electric motor with spring the driving unit of the sliding element can also be designed as a lifting magnet. Such a construction can result in a smaller construction size, and it has shown to be advantageous to arrange a spring between the sliding element and the lifting magnet. 
   To make safe running of the rolling members and the sliding element possible it has proven to be advantageous to arrange the sliding element in a housing that covers the bores and the rolling members. The construction size of a lock of this type can be advantageously reduced by that the second part of the first section of the shaft has a diameter reduction in the region of the bores with the rolling members which substantially corresponds to the width of the sliding element. This diameter reduction also serves for radially guiding the sliding element. 
   As an alternative of a radial movement of the sliding element also an axial movement of the sliding element can be provided. In such a case the sliding element includes an inclined surface extending in an axial direction by means of which a rolling member is displaced in such a way that an active connection between the coaxially aligned two parts of the first section of the shaft is produced. 
   An alternative design of the lock provides that the sliding element is displaceable in the axial direction of a shaft through a lever. This design offers, in particular, the advantage that the lock can have a compact construction because of the lever being axially movable, and all the components can be integrated in a locking cylinder of a usual size. 
   A further development of this embodiment provides that the lever is supported for rotation in the locking cylinder by one end thereof. The second end of the lever preferably engages an opening of the sliding element. It is further provided that the lever is guided with its central part in a worm wheel that is arranged on the driving shaft of the driving motor. Only a few rotations of the driving shaft of the driving motor are sufficient for reciprocating the sliding element by means of the lever between the two positions, in order to obtain the engaged or disengaged positions. The low number of required rotations of the driving shaft of the driving motor results in a very good energy balance and helps to a low energy requirement, so that corresponding energy storage means such as batteries or accumulators can have a very small size. 
   In an alternative embodiment the lever can be formed as a frame and include two projections which serve for connecting the lever to the sliding element on one side and to the locking cylinder on the other side. The lever is formed as a frame particularly for reasons of stability, which stability is important for the filigree components discussed herein. In addition, the frame construction offers advantages in guiding the lever on the worm wheel. Owing to its construction as a frame the lever can embrace the worm wheel. 
   Constructed in this way, the lever is fixed by its first projection to a gudgeon that is arranged so as to extend in the longitudinal direction of the sliding element and is fixed to the latter for pivoting. Preferably, said lever takes support on a tension and/or compression spring that is arranged on the gudgeon. 
   The connection of the lever to the worm wheel is preferably effected through two pins that a directed toward each other and engage with the thread of the worm wheel, thereby producing a form-fit connection between the worm wheel and the lever. 
   According to a further feature of the invention it is provided that in the sliding element on both sides of the second end of the lever there is respectively arranged at least one spring which is bent or released when the lever is moved. In their quality as energy storage means these springs support the movement of the lever and therefore are advantageous with respect to the required energy of the driving motor. 
   Preferably, the driving motor is arranged in the locking cylinder, in order to make a construction unit which is easy to mount. This further development also offers the advantage that already existing cavities and bores in the door leaf can be used when doors are retro-fitted. Accordingly, retro-fitting of existing doors with the lock according to the invention is easily possible. 
   As it is usual, the lock includes a locking nose which, according to the invention, is fixed for rotation with the shaft, particularly with the first section of the second part of the shaft. Preferably the locking nose is arranged on an annular body surrounding the shaft, in particular the first section of the second part of the shaft, which annular body has a bore receiving a pin, which bore is coaxially aligned with a bore in the shaft. This pin allows the locking nose to be securely mounted against rotation on the shaft. 
   According to a further feature of the invention it is provided that the bore extends up and into the locking nose, so that a pin of a relatively long length can be used to make the connection more stable. 
   It is further provided that the pin extends through a tangentially aligned groove in the first part of the shaft, so that the pin secures the shaft against its forcible removal also in the axial direction. 
   A further development of the lock provides that a first section of the shaft is formed in two parts, the coupling for producing the active connection after recognition of an authorisation code not being arranged between the two sections of the shaft but between the two parts of the first section of the shaft. This allows the shaft to be simply arranged in such a way that the coupling is provided on the inner side of the door, so that it is not or only hardly accessible from outside and hence burglarproof because it cannot be manipulated. In the lock according to the invention it is further provided that the two sections of the shaft are connected in a length-variable fashion, so that the shaft can be simply adjusted for door leafs of a different thickness, whereby the advantage is obtained that the lock according to the invention always allows the use of locking cylinders of a particular size. Accordingly, it is not necessary that locking cylinders of different lengths are used depending of the respective thickness of the door leaf. 
   According to a further feature of the invention it is provided that the two parts of the first section of the shaft are arranged coaxially to one another, thereby obtaining the advantage, in particular, that the lock according to the invention has a very compact construction. 
   It is further provided that the second section of the shaft has at least two diametrically opposite, axially aligned cavities that are engaged in a form-fit fashion by corresponding projections of the first part of the first section of the shaft. The form-fit connection of the two sections of the shaft results in a safe operation, with sufficient stability of the construction being given, which stability allows a reliable connection of the two sections of the shaft also in the case where high rotational forces for opening the catch bolt are required. 
   Preferably, the second part of the first section of the shaft is connected to a locking nose of the cylinder. The locking nose is, in particular, arranged in a manner fixed against rotation on a shaft section that extends coaxially with the first part of the section of the shaft and is connected in a form-fit fashion to the second part of the first section of the shaft. Preferably, the section of the shaft can be adjusted in a length-variable fashion with respect to the second part of the first section of the shaft, so that in this case, too the interconnected and interacting components can be precisely adjusted in order to keep the forces of movement within the lock small. 
   According to a further feature of the embodiment it is provided that the section of the shaft includes at least two diametrically opposite, axially aligned cavities which are engaged by corresponding projections of the second part of the first section of the shaft in a form-fit fashion. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features and advantages of the invention will become apparent from the following description of the accompanying drawing showing a preferred embodiment of the lock according to the invention. In the drawing it is shown by 
       FIG. 1  a part of a lock in a shaft and a locking cylinder in a perspective side view; 
       FIG. 2  the shaft according to  FIG. 1  in a perspective side view; 
       FIG. 3  a part of the shaft according to  FIG. 2  in a perspective side view; 
       FIG. 4  a basic diagram of the shaft according to  FIG. 2  in a side view; 
       FIG. 5  a coupling of a lock according to  FIG. 1  in a perspective side view; 
       FIG. 6  the coupling according to  FIG. 5  with the housing opened; 
       FIG. 7  a second embodiment of a lock in a sectional side view; 
       FIG. 8  the shaft and the driving unit of the second embodiment of the lock according to  FIG. 7  in a perspective view; 
       FIG. 9  a sliding element for the lock according to  FIGS. 7 and 8  in a perspective view; 
       FIG. 10  a lever for the actuation of the sliding element in a perspective view; 
       FIG. 11  a third embodiment of a lock in a sectional side view; 
       FIG. 12  a lever for the actuation of the sliding element in the lock according to  FIG. 11  in a perspective view and 
       FIG. 13  a fourth embodiment of a lock in a sectional side view. 
   

   DETAILED DESCRIPTION 
   A lock as represented in the  FIGS. 1 to 6  is formed as a mortise lock for installation in a door leaf and includes a locking cylinder  2  that is fixed in the door leaf which is not further shown. The locking cylinder  2  is penetrated by a shaft  3  that is formed of two sections  4  and  5 . 
   Rotary knobs (not shown in  FIG. 1 ) are fixed for rotation with the ends of these sections  4  and  5 , by means of which rotary knobs a locking nose  6  of the cylinder  2  mounted on shaft  3  can be pivoted if necessary upon recognition of an authorisation code that unlocks the lock  1 . 
   The above-mentioned rotary knobs are shown in  FIG. 4  and are designated by reference numbers  7  and  8 .  FIG. 4 , to which reference is made in the following, also shows a basic diagram of the shaft  3 . 
   The section  5  of shaft  3  is formed in two parts and includes two coaxially arranged parts  9  and  10 , of which the first part  9  is coaxially arranged for rotation in the second part  10  of the first section  5  of shaft  3 . The second part  10  of the first section  5  of shaft  3  is connected to the second section  4  of shaft  3  in a length-variable fashion. 
   Between the first part  9  and the second part  10  of the first section  5  of shaft  3  a coupling  11  still to be described in the following is provided, by means of which coupling the two parts  9  and  10  can be actively connected after recognition of an authorisation code. 
   The locking nose  6  of the locking cylinder  2  not shown in detail in  FIG. 4  is fixed for rotation with the second part  10  of the first section of shaft  3 . Consequently, the locking nose  6  can be pivoted both in the disengaged and engaged condition of the coupling  11 , using the rotary knob  7  that is provided inside the room. The rotary knob  8  provided on the outside of the building can be actuated for pivoting the locking nose  6  only if an active connection exists between the first part  9  and the second part  10  of the first section  5  of shaft  3  which can be produced through the coupling  11 . It can be seen that in the lock  1  according to the invention the structural components producing the active interconnection of the two parts  9  and  10  are arranged inside the room and are thus accessible from outside only under more difficult conditions. 
   The second section  4  of shaft  3  has on its end directed away from the rotary knob  8  two diametrically opposite, axially aligned cavities  12  which are engaged in a form-fit fashion by corresponding web-like projections  13  of the first part  9  of the first section  5  of shaft  3 . In a similar manner the second section  4  also includes web-like projections  14  engaging in a form-fit fashion in correspondingly formed cavities  15  of the first part  9  of the first section  5  of shaft  3 . 
   Owing to this construction it is possible to adjust the distance between the rotary knobs  7  and  8  corresponding to the material thickness of the door leaf (not further shown), this lock  1  allowing the insertion of merely a locking cylinder  2  of a particular length for door leafs of a different thickness. The coupling  11  is arranged in a housing  16  and consists of four rolling members  17  in the form of balls that are arranged in recesses  18  formed as radial bores in the second part  10  of the first section  5  of shaft  3 . The recesses or receiving constructions  18  are arranged equally spaced over the periphery of the second part  10  of the first section  5  of shaft  3  within the region of a diameter reduction  19 . 
   The first part  9  of the first section  5  of shaft  3  includes in the region of these recesses  18  cavities  20  that run about its surface area. Between the two cavities  20  webs  21  are formed which do, however, not protrude beyond the circumference of the first part  9  of the first section  5  of shaft  3 . 
   Finally, the coupling  11  includes a sliding element  22  which is guided radially movable with respect to the shaft  3  and which can be pushed into the diameter reduction  19 . 
   The diameter of the rolling members  17  formed as balls is larger than the depth of the recesses  18 . In the disengaged state the sliding element  22  is pulled out of the diameter reduction  19  to such an extent that the first part  9  of the first section  5  of shaft  3  can freely rotate within the second part  10  of the first section  5  of shaft  3 . Here, the rolling members  17  formed as balls are freely movable to such an extent that they evade radially within the recesses  18  when striking a web  21 . 
   In this condition the rotary knob  8  can be rotated without the locking nose  6  being moved and because of that the lock  1  opened. If an authorisation code is input in the lock  1 —this may be effected by means of a mechanical key, an electronic key or code numbers via a keyboard—the sliding element  22  will, upon recognition of the appropriate authorisation code, be pushed in a manner still to be described into the diameter reduction  19  to such an extent that the rolling members  17  lie in the cavities  20  and cannot be moved over and beyond the web  2 , whereby the active connection between the second part  10  and the first part  9  of the first section  5  of shaft  3  is produced, so that the locking nose  6  is movable using the rotary knob  8 . 
   In  FIG. 5  an embodiment of a driving unit  23  of the sliding element  22  is shown. The driving unit  23  consists of an electric motor  24  including a worm wheel  25  on its output shaft. In this worm wheel  25  an arm of a substantially L-shaped spring  27  is guided. The spring  27  has a second arm  28  and is supported on a cylindrically formed projection  29 , with said arms  26 ,  28  extending from this projection  29 . 
   The arm  28  is connected in a form-fit fashion to a knee lever  30  that can be pivoted about an axis  31  on one side and that is connected to the lower end of the sliding element  22  on the other side. 
   When the worm wheel  25  of the electric motor  24  is rotated, the arm  26  of the spring  27  in the initial position shown in  FIG. 5  will move away from the electric motor  24 , whereby the spring  27  is pivoted about the projection  29 . Owing to this pivoting movement the arm  28  moves clockwise, transferring the knee lever  30  to an almost straight position, whereby the sliding element  22  is moved in the radial direction towards shaft  3  and moves a ball-shaped rolling member  17  into a cavity  20 , in order to produce the active connection between the two parts  9  and  10  of the first section  5  of shaft  3 . 
   According to  FIGS. 1 and 2  the second part  10  of the first section  5  of shaft  3  is also formed in two parts, the connection between the two elements  32 ,  33  that form the second part  10  of the first section  5  being formed analogously to the length-variable design of the connection between the first section  5  and the second section  4  of shaft  3 . Accordingly, in this case, too corresponding projections and cavities are provided in the elements  32  and  33 . 
   An embodiment of the lock  1  shown in the  FIGS. 7 to 10  is also designed as a mortise lock for a door for installation in a door leaf. For components of this second embodiment which correspond to those of the first embodiment according to the  FIGS. 1 to 6  the same reference numbers are used in the  FIGS. 7 to 10 . 
   The second embodiment of the lock  1  shown in the  FIGS. 7 to 10  includes a locking cylinder  2  which is fixed in the door leaf not further shown. The locking cylinder  2  has a housing  34  in which a shaft  3  is supported for rotation, which shaft is formed of two sections  4  and  5 . The section  5  of shaft  3  is formed in two parts and includes two coaxially arranged parts  9  and  10 , of which the first part  9  is rotatably and coaxially arranged in the second part  10  of the first section  5  of shaft  3 . 
   Between the first part  9  and the second part  10  of the first section  5  of the shaft  3  a coupling  11  is arranged which is still to be described in more detail in the following and through which the two parts  9  and  10  can be actively interconnected or disconnected after recognition of an authorisation code for opening and/or closing the lock  1 . 
   The shaft  3  is supported in a bore  35  of the housing  34  and is sealed against the housing  34  in the region of the second part  10  of the first section  5 , using O-rings  36 . An additional O-ring  36  is provided between the first part  9  and the second part  10  of the first section  5  of shaft  3 . The O-rings  36  are inserted in corresponding grooves  37  in the components. 
   The housing  34  further includes two threaded bores  38  into which screws for fixing rosettes (not further shown) can be screwed. The rosettes may also carry rotary knobs (not further shown), by means of which a locking nose  6  of the locking cylinder  2  fitted on the shaft  3  can be pivoted, if necessary, after recognition of an authorisation code unlocking the lock  1 . 
   The locking nose  6  is formed as one piece with an annular body  39  that surrounds the second part  10  of the first section  5  of shaft  3  and is connected to this part in a manner fixed against rotation. To this end, the annular body  39  includes a bore  40  which is coaxially aligned with a bore in the shaft  3 , namely the second part  10 . In both bores  40  a pin  41  is inserted which connects the annular body  39  in a form-fit fashion to the second part  10 . The pin  41  extends over the whole length of the bores  40  that extend up and into the locking nose  6 . 
   In the region of the first part  9  of the second section  4  of shaft  3  the pin  41  penetrates through a continuous groove  42 , without preventing the two parts  9  and  10  from a relative rotational movement when the coupling  11  is not engaged. However, the two parts  9  and  10  are interconnected in the axial direction of the shaft  3  by means of said groove  42  and said pin  41 . 
   By the locking nose  6  being fixed for rotation with the second part  10  of the first section  5  of shaft  3  said locking nose  6  can be pivoted both in the disengaged and engaged state of the coupling  11 , using the rotary knob arranged inside the room, i.e. on the left side in  FIG. 7 . But the rotary knob arranged on the outside of the building, i.e. on the right side in  FIG. 7 , can be actuated for pivoting the locking nose  6  only if an active interconnection exists between the first part  9  and the second part  10  of the first section  5  of shaft  3 , which active interconnection can be produced through the coupling  11 . It can be seen that in the lock  1  according to the invention the structural components that produce the active interconnection between the two parts  9  and  10  are arranged inside the room and for this reason are accessible from outside only under more difficult conditions. 
   The coupling  11  is arranged within the locking cylinder and consists of four ball-shaped rolling members  17  arranged in recesses or receiving constructions  18  formed as radial bores in the second part of the first section  5  of shaft  3 . The recesses  18  are arranged equally spaced about the periphery of the second part  10  of the first section  5  of shaft  3 . 
   In the region of these recesses  18  the first part  9  of the first section  5  of shaft  3  has cavities  20  running about its surface area. Between the two cavities  20  webs are formed which do, however, not protrude beyond the circumference of the first part  9  of the first section  5  of shaft  3 . 
   Finally, the coupling  11  includes a sliding element  22  which is guided in such a manner that it is axially movable with respect to the shaft  3 . The sliding element  22  is arranged in a hollow space  43  within the housing  34  and consists, according to  FIG. 9 , of a base body  45  including bores  44  extending in the longitudinal direction and having arranged thereon a guide body  46 . 
   On one side of the base body  45  said bore  44  is provided with a slot  47  in which a lever  56  is guided which is still to be described in the following and which is shown in  FIG. 10 . In the region of its surface  49  facing the shaft  3  the guide body  46  is formed so that it approximately corresponds to a part of the outer surface area of the shaft  3  and includes a first surface section  50 , a second surface section  51  and an inclined surface  52  interconnecting said two surface sections  50  and  51 . The first surface section  50  is arranged at a distance to the outer surface area of the first part  9  of the first section  5  of shaft  3  which at least corresponds to the diameter of the rolling member  17 . The diameter of the ball-shaped rolling members  17  is larger than the depth of the recesses  18 . The second surface section  51  is arranged at a distance to the outer surface area of the first part  9  of the first section  5  of shaft  3  which is substantially smaller than the diameter of the rolling members  17 . On its front side the sliding element  22  which is formed in two parts includes cams  53  in the region of a first half shown in  FIG. 9 , which cams can be inserted for frictional engagement in corresponding bores in a second half (not further shown) of the sliding element  22 . 
   When the sliding element  22  is in a position in which the first surface section  50  is arranged under the rolling member  17 , the coupling  11  is disengaged and the two parts  9  and  10  of the first section  5  of shaft  3  are twistable relative to each other. When the sliding element  22  is now displaced in such a manner that the second surface section  51  comes in the region under the rolling members  17 , said rolling members  17  are pushed into the cavities  20  via the inclined surface  52 , so that a form-fit connection between the two parts  9  and  10  of the first section  5  of shaft  3  is produced. In this state the coupling  11  is engaged. 
   In the bore  44  of the base body  45  two springs  54  are inserted which take support on the front side of the bore  44 . Between the springs  54  a first end  55  of the lever  56  is arranged, which lever is rotatably supported in the housing  34  of the locking cylinder  2  by the second end  57  thereof. The lever  56  is movable along the slot  47  of the base body, with the moving distance being limited by the springs  54 . By its central part  58  the lever  56  engages a worm wheel  25  which is fixed against rotation on the driving shaft of an electric motor  24 . 
   The electric motor  24  is arranged under the sliding element  22  in the hollow space  43 . The lever  56  which is formed with a round cross-section is shown in detail in  FIG. 10  and is movable via the worm wheel  25  in the direction opposite to the displacement of the sliding element  22 . The second end  57  of the lever  56  is bent at right angles. 
   The movement of the sliding element  22  is damped by the springs  54 , so that a jerky engagement of the coupling  11  is prevented. The springs  54  further assist the movement of the sliding element  22  from the disengaged to the engaged position of the coupling  11  and vice versa. All in all, a smooth sliding movement of the sliding element  22  can thus be attained. The springs  54  also serve as energy storage means for the event that the movement of the sliding element  22  is obstructed. 
   The electric motor  24  is connected to a control electronic (not further shown), using cables and particularly stranded conductors (not further shown). The cables are passed through a cable duct  59  that is arranged in the lower part of the housing  34  in the longitudinal direction of the locking cylinder  2 . The cable duct  59  has an inside width of 1 mm and is sealed against the hollow space  43  for example by a rubber gasket, in order to prevent moisture and/or dirt from penetrating into the hollow space  43 . The O-rings  36  are arranged for the same purpose. 
   The control electronic serves for the verification of an authorisation code. If the control electronic recognizes an authorisation code that permits actuation of the lock  1 , the electric motor  24  is driven for a predetermined period of time and the worm wheel  25  is rotated. The sliding element  22  is moved through the lever  56  until the coupling  11  is engaged. This, however, does not require the time of driving the electric motor  24  to correspond to the movement of the sliding element  22 . In the engaged state of the coupling the locking nose  6  can be actuated from both sections  4 ,  5  of the shaft  3 , so that the lock  1  can be opened both from outside and inside. The control electronic can be arranged for example in the above-mentioned rosettes and/or the rotary knobs. 
   In the closed, i.e. locked state the outside rotary knob (not further shown) can be turned, without the locking nose  6  being moved and because of this the lock  1  opened. If an authorisation code is input now in the lock  1 —this can be done by means of a mechanical key, an electronic key, a biometric sensor, a transponder, radio transmission or code numbers via a keyboard—the sliding element  22  is displaced in the axial direction of the locking cylinder  2  after the correct authorisation code has been recognized, so that the rolling members  17  lie in the cavities  20  and cannot be moved over and beyond the web between adjacent cavities, whereby the active connection between the second part  10  and the first part  9  of the first section  5  of the shaft  3  is produced, so that the locking nose  6  can be moved, using the rotary knob  8 . 
     FIG. 11  shows a further embodiment of a lock, wherein components in  FIG. 11  that correspond to those of the embodiment shown in  FIG. 7  carry the same reference numbers. The essential differences between the two embodiments will be described in detail in the following. 
   In the embodiment according to  FIG. 11  the sliding element  22 , of which the surface facing the shaft  3  is formed corresponding to the surface of the sliding element  22  according to  FIG. 7 , has on the opposite surface thereof a cylindrically formed gudgeon  60  which is supported by its one end  61  for pivoting on the sliding element  22 . The gudgeon  60  is surrounded by a tension-compression spring  62  and penetrates by its free end opposite the end  61  through a bore  63  in a projection  64  of the lever  56 . The diameter of the bore  63  is slightly larger than the diameter of the gudgeon  60 , so that the gudgeon  60  is guided with a small tolerance within the bore  63  of the projection  64 . 
   According to  FIG. 12 , the lever  56  is frame-shaped and has a substantially rectangular base body  65  that delimits an opening  66 . Accordingly, the base body  65  respectively consists of two mutually parallel aligned long legs  67  and two short legs  68  that are also aligned parallel to each other and interconnect the two long legs  67 . The legs  67 ,  68  merge into each other in the form of a section of a circle of an arc. 
   In the region of the outer surface of the upper short leg  68  the first projection  64  having the bore  63  is arranged. 
   On the opposite side on the outer surface of the second short leg  68  a second projection  69  is provided having fixed to it a pin  70  that extends parallel to the longitudinal extension of the short leg  68  and can be inserted in a corresponding bore in the lock  1  within the region of the cable duct  59 , so that the lever  56  is supported for pivoting about the pin  70  within the hollow space  43 . 
   On their inner surfaces the long legs  67  have two mutually opposite pins  71  directed towards each other which are formed as truncated cones and which engage the worm thread of the worm wheel  25 . Accordingly, by rotation of the worm wheel  25  the lever  56  is pivoted about the pin  70 , so that the lever due to the fact that it is coupled to the gudgeon  60  and assisted by the tension-compression spring  62  displaces the sliding element  22  in the longitudinal direction of lock  1 , thus opening or closing the coupling  11 . 
   The second section  4  is connected to the first part  9  through a driving pin  72  in such a manner that tensile and pressure forces are transmissible even at a non-coaxial alignment of the second section  4  with the first part  9  and hence at a deviation of axes of these two components, without this causing any damage to the second section  4  or the first part  9 . 
   The same is true for the second part  10  and a driving shaft  73  connected to it. To this end, the second part  10  according to  FIG. 11  includes a location opening  74  in the longitudinal direction of the lock  1 . In this location opening  74  the driving shaft  73  is inserted, which driving shaft has on the end thereof which is located in the location opening  74  a radially extending bore that is penetrated by a driving pin  72 . 
   The second part  10  of the shaft  3  includes on its end having the location opening a radial bore  75  that is also penetrated by the driving pin  72 , the diameter of the radial bore  75  being slightly larger than the diameter of the driving pin  72 . The diameter on both radial ends can be differently dimensioned. 
   A further embodiment of a lock  1  is shown in  FIG. 13 . This embodiment of the lock substantially corresponds to the embodiment of the lock  1  according to  FIG. 11 , so that corresponding components are designated by corresponding reference numbers. 
   Differently from the embodiment according to  FIG. 11  the tension-compression spring  62  is not fixed to a gudgeon extending over the entire length of the tension-compression spring  62 . Rather it is said tension-compression spring  62  that is fixed to a gudgeon  60 , which forms part of the sliding element  22 , only by a partial portion of one end. By its second end the tension-compression spring  62  is fixed to the lever  56 . The lever  56  is pivoted through the worm wheel  25  of the driving motor  24 , so that the tension-compression spring  62  is bent or released. For the engagement of the sliding element  22  with the worm wheel  25  two projections (not further shown in  FIG. 13 ) are provided on the sliding element  22 . The displacement of the sliding element  22  is then effected through the tension-compression spring  62 . 
   In the embodiment shown the sliding element  22  is formed of a plastic material and substantially corresponds to the sliding element  22  shown in  FIG. 12 . 
   The lock  1  according to  FIG. 13  further includes a recess or receiving construction  76  in which a plate bar  77  can be inserted which for example includes an integrated circuit for controlling the motor  24  and, if necessary, data in the form of a locking secret. The plate bar  77  can be accordingly designed as an evaluation plate bar. 
   In addition, the lock  1  includes a catch  78  between the two sections  4  and  5  of the shaft  3 . This catch  78  makes sure that when the sliding element  22  is actuated, in particular when it is moved from the engaged to the disengaged state, the two sections  4  and  5  of the shaft  3  are arranged in a defined position in which the recesses  18  are arranged centrical over the cavities  20 , in order to avoid that the rolling members  17  and the sliding element  22  are clamped. 
   The catch  78  consists of a radial bore  79  formed as blind hole in the second section  4  and a radial bore  80  in the first section  5  of the shaft  3 . In the radial bore  79  a spring  81  and a ball  82  are supported, which ball is pushed at the defined position into the bore  80  of the first section  5 . The diameter of the ball  82  is slightly larger than the diameter of the radial bore  80 , in order to avoid that the ball  82  is pushed out.