Abstract:
A locking cylinder having a two-part housing, including an upper part and a lower part. A cylinder core is received in the housing and can be actuated by turning a key. The housing of the locking cylinder is fastened to the body of a vehicle by a fastener. The fastener used to fasten the housing of the locking cylinder on the body is also used as a connector for fastening the housing upper part on the housing lower part.

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns a locking cylinder that consists of a cylinder core, which is rotatably supported in a two-part bearing housing and initiates certain functions in the vehicle when a key is turned. 
     Vehicle doors or hatches are an important area of application of locking cylinders of this type. The functions arising in this case are the securing and releasing of the doors and hatches. This is intended to bar access to the vehicle by unauthorized persons. Authorized persons have a key that is assigned to the locking cylinder and is inserted in a key slot of the cylinder core and thereby moves the spring-loaded tumblers into the cylinder core. The cylinder core can then be moved by means of the key from a home position to various operating positions. The upper and lower parts of the bearing housing serve the purpose of rotatably supporting the cylinder core and hold other possible components of the housing. At one end of the joined housing parts, the key slot is accessible to the key, while a driver is rotatably supported at the other end. The driver transmits a rotation of the cylinder core via a connecting rod to the functional parts in the vehicle located behind the locking cylinder. 
     In the previously known locking cylinder, the two parts of the housing, together with the components they hold, must be held together by pins. When the two parts of the housing have to be separated from each other, e.g., to replace a defective component, the removal of the spiral pin is a laborious operation. In addition, points of application for the fastening means must be provided on the housing, by which the housing can be mounted on the body of the vehicle. This is time-consuming and takes up too much space. 
     EP 0 221 375 A1 concerns the “sandwich mounting” of a locking cylinder, the details of which are not shown, in a hole of a body wall. Two mounting parts, which engage each other from opposite sides of the body wall and are joined by a bayonet coupling, serve as mounting means for the installation of this locking cylinder. The two mounting parts have no bearings for rotatably supporting the cylinder core of the locking cylinder, the details of which are not shown. 
     DE 203 12 399 U1 also discloses a sandwich mounting of a locking cylinder in a hole of a pane of glass by means of two mounting parts, which are supported with flanges on the two opposite sides of the pane of glass. The two mounting parts are tightened relative to each other by three bolts and thus hold the locking cylinder between them. The bolts have no effect with respect to holding the components of the locking cylinder together; the locking cylinder is already completely assembled when installed and has no need of further means to hold it together. 
     Finally, GB 2 245 643 A also describes a sandwich mounting of a fully assembled locking cylinder in a central hole of a door. To this end, two mounting parts that fit against the two outside surfaces of the door are tightened relative to each other by two screws. The screws do not interact with the components of the locking cylinder. First, the two mounting parts are attached to the door, and only then is the assembled locking cylinder inserted. One-piece, elastically deformable retention fingers are used to mount the locking cylinder in one of the two mounting parts. These retention fingers have hook-like ends that snap into an annular, circumferentially continuous groove. 
     In DE 200 16 108 U1, a complete locking cylinder is inserted in the drill hole of a base plate, which is mounted on the rear side of a vehicle door. A pull handle is then twisted in, so that it is rotatably supported from the outside of the door in the base plate on the rear side. Then, on the front side, a cover is placed over the protruding section of the locking cylinder, which secures the pull handle in its mounted position. A fastening screw passes through a drill hole in the cover and a drill hole in the base plate and is screwed into a threaded hole in the housing of the locking cylinder. The mounted locking cylinder is thus nonrotatably fixed in the drill hole of the base plate. The fastening screw has no effect with respect to holding together the components of the locking cylinder. 
     WO 00/43619 A1 shows, first of all, an external housing that is permanently mounted in a receptacle of a door. The external housing holds an internal housing, which has a cross-sectional profile in the form of a figure eight and consists of an upper housing cavity and a lower housing cavity. The lower housing cavity has a cylindrical bore for the rotatable support of the actual cylinder core, while the upper housing cavity always accommodates a number of sections of pin tumblers, of which a last section is positioned in the cylinder core when the key is inserted. To mount the internal housing in the external housing, the key must be inserted and brought into a well-defined inclined position to expose a slot in the internal housing. Only then, during the mounting operation, can an inner projection in the receptacle of the external housing be moved into the slot in the internal housing. The means for fastening the internal and external housing have nothing to do with holding the cylinder core and the internal housing together, but rather a separate locking ring is used for this purpose, which snaps into a groove in the cylinder core that projects from the internal housing. 
     SUMMARY OF THE INVENTION 
     The objective of the invention is to develop a locking cylinder which avoids the disadvantages mentioned above. This objective is achieved by the measures of the present invention, which have the following special significance. 
     Although the locking cylinder is a preassembled unit, which can be handled as a self-contained unit when it is being mounted on the vehicle body, its components are not yet fastened to each other. Before it is mounted, the unit can simply be separated into the components of the cylinder. In the unit, the projecting tab of the upper part of the housing and a corresponding mating part of the lower part of the bearing housing lie directly against each other, and the holes for fastening them together are aligned. As a result, the same bolt fastening means can be used both for bolting together all of the components of the unit and for bolting the unit to the body. 
     In the invention, the bolt fastening means for mounting the housing on the body has a dual function. The first, customary, function consists in using the same bolt fastening means for simultaneously joining the upper part and the lower part and thus for rotatably supporting the cylinder core contained therein. Accordingly, a single means and a single handling of this bolt fastening means are sufficient for carrying out several functions in the locking cylinder at the same time. Space and assembly time are saved in this way. At the same time, the possible separation of the two parts of the housing is very simple, because as soon as the bolt fastening means is removed from the body, the components of the unit are also no longer attached to each other and can be immediately separated from each other. This allows replacement and repair of the components of the locking cylinder to be carried out as fast as possible. Access is obtained to the components enclosed inside the housing. 
     Further measures and advantages of the invention are revealed in the description below, and the accompanying drawings, which illustrate a specific embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  shows an axial section through an assembled locking cylinder before it is mounted on the body of the vehicle. 
         FIG. 2  shows a perspective view of the locking cylinder shown in  FIG. 1 . 
         FIGS. 3   a  and  4   a , on the one hand, and  FIGS. 3   b  and  4   b , on the other hand, show two oppositely directed perspective views of the upper part of the housing and the lower part of the housing of the locking cylinder of  FIG. 1  before they are joined to each other and before the other components are installed inside the housing. 
         FIG. 5  shows an axial section, analogous to  FIG. 1 , through the locking cylinder mounted on the body of the vehicle. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As is best seen in  FIG. 1 , the housing  10  of the locking cylinder consists of two housing parts  11 ,  12 , whose appearance is revealed by the perspective views in  FIGS. 3   a  to  4   b . To make it easier to distinguish the two parts of the housing, the housing part  11  that faces the user will be referred to as the “lower part”, and the housing part  12  will be referred to as the “upper part”. The two parts  11 ,  12  of the housing  10  enclose a large number of components, which in the assembled state constitute a preassembled unit  15 , as shown in  FIG. 1 . 
     These components within the housing  10  include above all a cylinder core  20 , which is rotatably supported inside a free-running sleeve  21 . The free-running sleeve  21  is normally at rest in the housing  10 . The cylinder core  20  has an axial key slot  22 , which is traversed by several chambers  23 . The chambers  23  serve to hold spring-loaded tumblers, whose ends, which are not seen in the drawing, fit into at least one axial groove of the free-running sleeve  21 . The cylinder core  20  is then rotationally secured. 
     To release the cylinder core  20  for rotation, an associated key (not shown) must be inserted in the key slot  22  in the direction indicated by the arrow  24 . The key then moves the tumblers flush with the cross section of the cylinder core  20 . The ends of the tumblers then no longer engage the groove of the free-running sleeve  21 , and the cylinder core  20  can be turned by the inserted key. 
     When the key is turned, the torque is transmitted from a terminal output end  25  of the cylinder core  20 , via a free-running device  26  that comprises several components, to a driver  27 , which is located at the inner outlet  13  of the housing  10 . A pulse spring  28 , which works to hold the driver  27  in a well-defined home position, normally also acts on the cylinder core  20 . In the normal case, when the free-running sleeve  21  is at rest, the cylinder core  20  is also kept in this home position via the free-running device  26 . 
     An armored faceplate  29  is mounted in front of the outer outlet  14  of the housing  10  and is nonrotatably joined with the cylinder core  20  by means of pins and recesses. An elastomer disk  19  is installed between the faceplate  29  and the cylinder core  20 . The faceplate  29  defines the insertion hole for the key and is shaped to conform to the cross section of the key. The elastomer disk  19  has a sealing function and at the same times serves as a shock absorber for forceful blows made in the direction of insertion arrow  24  in an attempt to break into the vehicle. 
     As is best seen from the detail views of  FIGS. 4   a  and  4   b , the upper housing part  12 , which is partly shaped like a sleeve, is provided with a tab  16  with a hole  17 . As  FIG. 1  shows, in the assembled state, the tab  16  extends obliquely to the axis  18  of the locking cylinder and thus the cylinder core  20 . The axis  18  is indicated by a dot-dash line in  FIG. 1 . 
       FIGS. 3   a  and  3   b  show the appearance of the lower part  11  of the housing. As is also apparent from the axial section in  FIG. 1 , the lower part  11  has a lateral housing extension  38  with a recess  39 , whose base region forms a mating part  36  for the tab  16 . The housing extension  38  is provided with a threaded receptacle  37 . 
     When the unit  15  of  FIG. 1  is being assembled, the two housing parts  11 ,  12  can be temporarily held together by locking means and their mating devices, which are not shown in the drawing. However, this type of locking is obtained above all when, as  FIG. 1  illustrates, the tab of the housing upper part  12  fits into the recess  39  of the housing extension  38  of the housing lower part  11 . The final connection between the two housing parts  11 ,  12  is realized in the present case by fastening means  30 , which mount the locking cylinder on the body  33  of the vehicle. This will be explained in greater detail in connection with  FIG. 5 . 
       FIG. 5  shows a portion of a body  33  of a vehicle, such as a vehicle hatch, which is to be equipped with the locking cylinder. The fastening means consists of a bolt  30 . The body  33  has a well-defined mounting location  34  for the locking cylinder. A hole  35  for the bolt  30  is provided there. In the fastened state, the shaft of the bolt  30  passes through the hole  35  and the tab  16  in the housing upper part  12 , while the threading  32  of the bolt engages the aforementioned threaded receptacle  37  of the housing extension  38 . The head  31  of the bolt  30  rests against the upper side of the body mounting location  34 . In the fastened state shown in  FIG. 5 , the axis  41  of the bolt  30 , which is indicated by a dot-dash line, extends at an acute angle  42  to the axis  18  of the cylinder core  20 . 
     In the fastened state shown in  FIG. 5 , the driver  27  of the locking cylinder is connected by a rotary joint  40  with those units in the vehicle which are to carry out the desired functions in the vehicle when the locking cylinder is actuated by being turned. In the present case, the rotary joint  40  is intended to connect the driver with a lock in the hatch of the vehicle. This lock can be switched between a secured position and a released position. It goes without saying that the driver could also be used to actuate any other desired functions in the vehicle. 
     In the event of a forceful rotation of the cylinder core with burglary tools by unauthorized persons, the cylinder core  20  remains engaged with the free-running sleeve  21  by the aforementioned outwardly projecting ends of the tumblers. A catch between the free-running sleeve  21  and the housing  10  is then released, and the cylinder core  20  rotates inside the housing along with the free-running sleeve  21 . During forced rotation, the free-running device  26  decouples the driver  27  relative to the terminal output end  25  of the cylinder core  20 . Therefore, despite the forceful rotations by means of the burglary tool, the driver  27  and thus the rotary joint  40  connected with it remain at rest, and so no function is carried out in the vehicle. 
     LIST OF REFERENCE NUMBERS 
     
         
           10  housing 
           11  lower part of  10   
           12  upper part of  10   
           13  inner outlet of  10   
           14  outer outlet of  10   
           15  unit 
           16  tab on  12   
           17  hole in  16   
           18  axis of the locking cylinder 
           19  elastomer disk 
           20  cylinder core 
           21  free-running sleeve 
           22  key slot 
           23  chamber 
           24  arrow indicating the direction of insertion of the key 
           25  terminal output end 
           26  free-running device 
           27  driver 
           28  pulse spring 
           29  faceplate 
           30  fastening means, bolt 
           31  head of  30   
           32  threading of  30   
           33  body of the vehicle 
           34  mounting location on  33   
           35  hole in  34   
           36  mating part for tab  16  on  38   
           37  threaded receptacle in  38   
           38  housing extension on housing part  11   
           39  recess in  38  for  36   
           40  rotary joint at  27   
           41  axis of  30   
           42  acute angle between  41 ,  18