Abstract:
The invention relates to a fitting ( 10 ) for the seat of a vehicle, particularly for a motor vehicle, comprising a first fitting part ( 11 ), a second fitting part ( 12 ) which is mechanically linked to the first fitting part ( 11 ), a locking eccentric which is provided primarily to lock the fitting ( 10 ), a running eccentric ( 31 ) which is primarily provided for driving a relative rolling movement of the second fitting part ( 12 ) on the first fitting part ( 11 ) in order to adjust the fitting ( 10 ), and a driver ( 21 ) which controls the locking eccentric at the beginning of the adjusting movement in order to cancel the locking effect and which drives at least the running eccentric ( 31 ) during the adjusting movement. The rotating driver ( 21 ) impinges upon the rotating running eccentric ( 31 ) without any lateral force.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     The present application is a continuation of International Application PCT/EP2005/013428, which was filed Dec. 14, 2005. The entire disclosure of International Application PCT/EP2005/013428, which was filed Dec. 14, 2005, is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to a fitting for a vehicle seat, in particular for a motor vehicle seat, with the fitting having a first fitting part, a second fitting part in geared connection with the first fitting part, a locking eccentric, which is provided primarily for locking the fitting, a running eccentric, which is provided primarily for driving a relative rolling movement of the second fitting part on the first fitting part for adjusting the fitting, and a driver that, at the start of the adjusting movement, controls the locking eccentric for canceling the locking effect and during the adjusting movement drives the running eccentric.  
         [0003]     A fitting of the type described immediately above is known from DE 39 41 215 A1. DE 39 41 215 A1 discloses that its fitting attaches the backrest of a vehicle seat to the seat part of the vehicle seat in a manner so that the inclination of the backrest may be adjusted. In the fitting of DE 39 41 215 A1, a locking eccentric defined by two wedge segments and a running eccentric defined by a sickle-shaped centering segment are located on a collar of the first fitting part. The locking eccentric serves for locking the fitting whereas, during the adjusting movement, the running eccentric alone undertakes the mounting and driving of the fitting parts. By the choice of materials and the shape of the components, increased friction may occur locally during the adjusting movement, which increases the necessary operating forces. With an adjusting movement counter to the loading direction, i.e. counter to the direction of a force exerted by the user on the backrest or otherwise counter to the direction of the weight force of the backrest, this is made considerably more noticeable than in the loading direction.  
       BRIEF SUMMARY OF SOME ASPECTS OF THE INVENTION  
       [0004]     An aspect of the present invention is the provision of improvements to a fitting of the type described immediately above, in particular for reducing the operating forces counter to the loading direction. In accordance with one aspect of the present invention, a fitting for a vehicle seat, in particular for a motor vehicle seat, has a first fitting part, a second fitting part in geared connection with the first fitting part, a locking eccentric that is primarily (e.g., at least) for locking the fitting, a running eccentric that is primarily (e.g., at least) for driving a relative rolling movement of the second fitting part on the first fitting part for adjusting the fitting, and a rotatably mounted driver. The driver is for controlling the locking eccentric to unlock the fitting at a start of an adjusting movement. The driver is also for driving at least the running eccentric during the adjusting movement so that the running eccentric drives the relative rolling movement of the second fitting part on the first fitting part. The driving comprises the driver rotating and impinging on the running eccentric without lateral force.  
         [0005]     Because the rotating driver impinges on the rotatable running eccentric without lateral force (relative to a common axis of rotation), the driving torque of the driver is applied coaxially to the running eccentric, so that a movement may be carried out under the same frictional conditions. A tipping movement about an instantaneous center of rotation triggered by lateral forces and overriding the rotation, which would lead to a local increase in friction and thus to increased operating forces, is avoided. The required freedom from lateral forces may therefore be understood such that minimal lateral forces which are required, for example, by component tolerances, are allowed, as long as they do not substantially alter the friction.  
         [0006]     The impingement without lateral force is, for example, achieved by the contact points between the driver and the running eccentric being distributed uniformly over the periphery and being at the same distance from the common axis of rotation of the driver and of the running eccentric. In an embodiment with slot-pin-guides, which offers the advantage of idle motion to determine the time sequence of the control of the locking eccentric and the running eccentric, for example two pins and two elongated holes are arranged point symmetrically to one another relative to the axis of rotation of the driver and the running eccentric. Any association of pins and elongated holes to the driver on the one hand and to the running eccentric on the other hand is possible. It is, however, also possible to provide a rotationally fixed connection between the driver and the running eccentric, for example by the contact points—preferably defined by pins and holes—being configured without play. The rotationally fixed connection may, therefore, be developed such that the driver and the running eccentric form a single component, i.e. the driver is configured as (e.g., comprises) a running eccentric.  
         [0007]     Because the running eccentric is mounted by way of rolling-contact bearing bushings or plain bearing bushings, both relative to the first fitting part and also relative to the second fitting part, a small amount of friction may be selected (e.g., may exist) between the running eccentric and the rolling-contact bearing bushing or plain bearing bushing (or between a rolling-contact bearing bushing or plain bearing bushing and the associated fitting part) which is less than the friction between the locking eccentric and at least one of the fitting parts, required to lock the fitting. This reduces the operating forces. The locking eccentric serves for locking the fitting and the positioning without play. With regard to the geometry, the bearing of the running eccentric against the rolling-contact bearing bushing or plain bearing bushing is carried out radially outwardly and radially inwardly relative to the axis of rotation thereof. Preferably, each of the two rolling-contact bearing bushings or plain bearing bushings may be connected fixedly in terms of rotation to the fitting associated therewith, for example pressed into an aperture or a collar or pressed onto a collar. Alternatively, one (or both) of the two rolling-contact bearing bushings or plain bearing bushings may be connected fixedly in terms of rotation to the running eccentric, for example pressed into or onto the running eccentric.  
         [0008]     The running eccentric may be of sickle-shaped configuration and extend in the peripheral direction, for example over more than 180°. It is, however, possible that the running eccentric is of annular configuration, i.e. completely closed in the peripheral direction. In the variants with low-friction relative movement between the corresponding rolling-contact bearing bushing or plain bearing bushing and the associated fitting part and a sickle-shaped running eccentric, the rolling-contact bearing bushing or plain bearing bushing only requires to be formed over a part of the periphery adapted to the running eccentric, i.e. it may be configured as a sickle-shaped rolling-contact bearing segment or plain bearing segment.  
         [0009]     The precise functional separation between the locking eccentric and the running eccentric is not present in all situations. With a locked fitting, the locking eccentric consecutively undertakes the locking function, the positioning without play and generally also the mounting of the fitting parts onto one another. However, the running eccentric is also able to contribute to the mounting of the fitting parts. During an adjusting movement counter to the loading direction, the running eccentric alone normally undertakes the mounting of the fitting parts and the driving of the rolling movement. The loading direction is the direction of a force exerted by the user onto the seat components, which is applied by way of the fitting, or otherwise the direction of the weight force of the seat components. More specifically, during an adjusting movement in the loading direction, the running eccentric primarily undertakes the mounting of the fitting parts and the driving of the rolling movement, but it is possible—depending on the situation and boundary conditions—that the locking eccentric or the components thereof assist the mounting and the driving.  
         [0010]     The control of the locking eccentric, which preferably consists of two wedge segments, may be carried out by way of a driving segment of the driver, so that the wedge segments approach one another and cancel the locking effect, with the amount of the approach generally fluctuating and being dependent on the local frictional conditions and component tolerances. The driving of the running eccentric is also possible by way of a driving segment, which is effective with an annular running eccentric, for example inside a recess.  
         [0011]     The control may also be carried out such that the driver brings the wedge segments to bear against one another, namely by moving both wedge segments or by moving only one wedge segment, for example the wedge segment which is loaded less relative to the loading direction. The wedge segments are preferably moved by using an annular (e.g., substantially annular) spring, which is provided in the initial locking position for pressing the wedge segments apart. The driver preferably impinges on one or both of the end fingers of the annular spring. The end fingers of the annular spring engage in the wedge segments, for example in holes thereof. The effect may be carried out by way of suitably configured sliding links which are provided, for example, on a pivotable connecting link coupled to the driver. If the running eccentric is arranged axially between the driver and the locking eccentric, slots penetrating the running eccentric may be provided, in order to allow the end fingers of the annular spring an unhindered penetration of the wedge segments.  
         [0012]     With the fitting according to the invention, an adjustment of the inclination of a backrest may, for example, be undertaken. The application may be extended to adjusting a further pivotable region of a vehicle seat. The fitting according to the invention is preferably designed for a manual drive but may also be driven by motor. The invention may also be used with other geared fittings, driven manually or by motor.  
         [0013]     Other aspects and advantages of the present invention will become apparent from the following.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The invention is described below in more detail with reference to three embodiments, together with a plurality of modifications, shown in the drawings, in which:  
         [0015]      FIG. 1  is an exploded view of the first embodiment.  
         [0016]      FIG. 2  is a schematic view of a vehicle seat.  
         [0017]      FIG. 3  is a perspective partial view of the first embodiment.  
         [0018]      FIG. 4  is a partial view of a first modification of the first embodiment.  
         [0019]      FIG. 5  is a partial view of a second modification of the first embodiment.  
         [0020]      FIG. 6  is a partial view of a third modification of the first embodiment.  
         [0021]      FIG. 7  is an exploded view of the second embodiment.  
         [0022]      FIG. 8  is an axial section through the second embodiment.  
         [0023]      FIG. 9  is an axial section through the third embodiment.  
         [0024]      FIG. 10  is an exploded view of the third embodiment. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0025]     A vehicle seat  1  for a motor vehicle comprises a seat part  3  and a backrest  4 . The inclination of the backrest  4  may be manually adjusted relative to the seat part  3 . The inclination adjustment of the backrest  4  is carried out by way of a handwheel provided at the side and a drive shaft that drives two fittings  10  together. The two fittings  10  are respectively attached to the two sides of the vehicle seat  1  and support the backrest  4 .  
         [0026]     Each fitting  10  is configured as a geared fitting in which a first fitting part  11  and a second fitting part  12  are connected to one another via a gear for locking and adjusting. The two fitting parts  11  and  12  have a substantially flat shape and are composed of steel. The first fitting part  11  is primarily connected to the structure of the backrest  4  (fixed to the backrest) and therefore shown at the top in the drawings. Accordingly, in the present case, the second fitting part  12  is primarily fixed to the seat part and shown at the bottom in the drawings. The positions of the fitting parts  11  and  12  may also be interchanged, so that the bearings and the movements of the components relative to one another may always be seen conceptually with respect to the system of the fitting  10 , and are not limited by the relative positions of the fitting parts  11  and  12 .  
         [0027]     To form the gear, a toothed wheel  16  with an external toothing is impressed on the second fitting part  12  and a toothed ring  17  with an internal toothing is impressed on the first fitting part  11 , and these toothings mesh with one another. The diameter of the addendum circle of the external toothing of the toothed wheel  16  is smaller by at least one tooth height than the diameter of the dedendum circle of the internal toothing of the toothed ring  17 . The corresponding difference between the number of teeth of the toothed wheel  16  and the toothed ring  17  allows a rolling movement of the toothed ring  17  on the toothed wheel  16 . The first fitting part  11  has a collar  19  that is formed on the side facing the toothed wheel  16 , and the collar  19  is concentric to the internal toothing of the toothed ring  17 . Directional information used hereinafter is with reference to a cylindrical coordinate system that is centered with respect to the collar  19 .  
         [0028]     A driver that is denoted in the first embodiment by  21  is mounted, by way of a central hub  22 , with play in the collar  19  of the first fitting part  11 . The driver  21  is, for example, composed of plastic or a metallic material. The driver  21  is provided with a central axial receiver  23  that penetrates the hub  22  and is profiled to adapt to an external splined profile of the drive shaft. On the front face of the driver  21  facing away from the hub  22 , a cover disk of greater diameter may be formed on the driver  21 . The driver  21  is axially secured to the outer face of the first fitting part  11  by a retaining ring  24  which is clipped on. For receiving the axially acting forces, retaining plates  25  are respectively welded onto the two fitting parts  11  and  12 , and overlap the respective other fitting part, without hindering the adjusting movement. For the sake of clarity, only one of these retaining plates  25  is shown in the drawings.  
         [0029]     Two wedge segments  27  define a locking eccentric. The wedge segments  27  are preferably produced from steel (in particular sintered material) or a different metallic material and are arranged axially between the driver  21  and the first fitting part  11 . The wedge segments  27  are supported by way of their circular-arc-shaped curved inner faces on the collar  19 . With their similarly circular-arc-shaped curved outer faces, eccentric to the inner faces, the wedge segments  27  serve for the mounting of the rolling-contact bearing bushing or plain bearing bushing, which is denoted hereinafter as the first plain bearing bushing  28 . The first plain bearing bushing  28  is pressed fixedly in terms of rotation into the second fitting part  12 . The friction between the first plain bearing bushing  28  and the wedge segments  27  is markedly less than the friction between the wedge segments  27  and the collar  19 . The broad ends of the wedge segments  27  face one another and receive with respective holes  29  (or jaws open in the peripheral direction) respective angled end fingers of a pretensioned annular (e.g., substantially annular) spring  30 . The spring  30  acts on the wedge segments  27  and presses the wedge segments apart in the peripheral direction, in order to lock the fitting  10  in the initial position.  
         [0030]     A running eccentric, which is denoted by  31  in the first embodiment, is arranged axially adjacent to the wedge segments  27 . The running eccentric  31  is, for example, made from plastic or a metallic material. The running eccentric  31  bears radially outward with its circular-arc-shaped curved outer face against the first plain bearing bushing  28  and also serves for the mounting of the first plain bearing bushing  28 . The running eccentric  31  bears radially inward with its similarly circular-arc-shaped curved inner face, which is arranged eccentrically to the outer face, against a further rolling-contact bearing bushing or plain bearing bushing, which is denoted hereinafter as the second plain bearing bushing  33 . The second plain bearing bushing  33  is inserted fixedly in terms of rotation into the running eccentric  31  (and may be rotated relative to the collar  19  with little force) or alternatively is located fixedly in terms of rotation on the collar  19  (the running eccentric  31  being rotatable relative to the plain bearing bushing  33 ). The friction between the plain bearing bushing  28  and  33 , on the one hand, and the running eccentric  31  or the collar  19 , on the other hand, is also markedly less than the friction between the wedge segments  27  and the collar  19 .  
         [0031]     In the locked initial position, the locking eccentric presses, in the extension of the direction of its eccentricity, the toothed wheel  16  at a thus defined engagement point into the toothed ring  17 . The running eccentric  31  is aligned according to the eccentricity of the locking eccentric, so that two eccentrics are arranged adjacent to one another. The locking eccentric undertakes primarily, i.e. normally alone, the mounting of the two fitting parts  11  and  12  onto one another and the positioning without play and thus the locking effect. Optionally, the running eccentric  31  also proportionately contributes to the mounting. When the driver  21  is driven, the wedge segments  27  approach one another counter to the force of the annular spring  30  whereby the locking effect is canceled. The running eccentric  31  undertakes primarily, i.e. normally alone, the mounting of the two fitting parts  11  and  12  (and thus the driving of the rolling movement). In particular during adjusting movements in the loading direction, occasionally mixed conditions occur and one or both of the wedge segments  27  may contribute to the mounting and to the driving. The running eccentric  31  slides—during its rotation about the collar  19  of the first fitting part  11 —along the second fitting part  12  by displacing the eccentricity direction and thus by displacing the point of engagement of the toothed wheel  16  in the toothed ring  17  which is represented as the wobbling rolling movement.  
         [0032]     The aforementioned configuration of the driver  21 , locking eccentric and running eccentric  31  is the same for all embodiments and the modifications thereof. Differences exist in the further detailed configuration of these and further components described hereinafter.  
         [0033]     In the first embodiment, a driving segment  35  is formed on the driver  21  on the front face with the hub  22 . The driving segment  35  is delimited in the peripheral direction of the driver  21  by respective driving lugs  36 . The driving segment  35  grips with play with its driving lugs  36  between the narrow ends of the wedge segments  27 . The running eccentric  31  is of sickle-shaped configuration and arranged axially between the driver  21  and the wedge segments  27 . Two slots  37  extend in the peripheral direction and axially penetrate the running eccentric  31 . The end fingers of the annular spring  30  respectively penetrate the slots  37  unhindered and with play, and then respectively extend into the holes  29  of the wedge segments  27 , without coupling the wedge segments  27  to the running eccentric  31 .  
         [0034]     Two axially protruding pins  38  are formed on the running eccentric  31  on the front face facing the driver  21 , and the protruding pins  38  are radially opposite one another. Each pin  38  engages in an elongated hole  39  arranged in the peripheral direction. In the initial position for each pin  38  and its respective hole  39 , the pin  38  is arranged approximately in the center of the elongated hole  39 . The pins  38  and the elongated holes  39  are arranged, therefore, such that when a pin  38  bears against the end (e.g., side) of the associated elongated hole  39  that is closer to the driving segment  35  (the lower end in  FIGS. 1 and 3 ) the running eccentric  31  is still at a distance from the driving lug  36 .  
         [0035]     During the driving, a torque is firstly introduced into the driver  21  and then transferred to the locking eccentric by one of the driving lugs  36  impinging on the associated wedge segment  27  and pressing the wedge segments  27  together. If, with the further rotation of the driver  21 , the idle motion predetermined by the elongated holes  39  is passed through, the running eccentric  31  is impinged upon on the pins  38  and driven.  
         [0036]     Because two systems of pins  38  and elongated holes  39  radially opposing one another are provided, the impingement and driving of the running eccentric  31  is carried out by the driver  21  without lateral forces, i.e. the torque acts (point) symmetrically to the centrally arranged axis of rotation of the driver  21 . The running eccentric  31  then slides with substantially the same (low) friction at each of the plain bearing bushings  28  and  33 . With lateral forces, i.e. a torque acting asymmetrically, a tipping of the running eccentric  31  would take place about an instantaneous axis of rotation (at the contact point between the driver  21  and the running eccentric  31 ) which might result in a slight local increase in the normal force of the running eccentric  31  onto the plain bearing bushings  28  and  33  and thus a slightly increased friction.  
         [0037]     Modifications are possible to the disclosed first embodiment without lateral force, which differ in the control of the wedge segments  27  or the mounting. This control is carried out by using the annular spring  30  so that the driving segment  35  is omitted.  
         [0038]     In a first modification to the first embodiment, which resembles the first embodiment except where described differently, the same components are provided with the same reference numerals and similarly acting components are provided with reference numerals with an apostrophe.  
         [0039]     Two links  41 ′ are articulated symmetrically on the driver  21 ′, which in turn are articulated symmetrically on a connecting link  43 ′. The connecting link  43 ′ is rotatably mounted in the running eccentric  31  which, for example, may be configured as a complete ring. Two sliding links  45 ′ in the connecting link  43 ′ allow the end fingers of the annular spring  30  to penetrate the slot  37  of the running eccentric  31  into the holes  29  of the wedge segments  27 .  
         [0040]     If the driver  21 ′ is driven, it swivels the connecting link  43 ′ by way of the links  41 ′. As a result of the shape of the sliding links  45 ′, the end fingers of the annular spring  30  move toward one another until the wedge segments  27  bear against one another, so that the locking effect is canceled. The running eccentric  31  is rotated without lateral force due to the doubly present pins  38  and elongated holes  39 .  
         [0041]     A second modification of the first embodiment resembles the first modification and the first embodiment except where described differently, which is why the same components are provided with the same reference numerals and similarly acting components are provided with reference numerals with two apostrophes.  
         [0042]     The driver  21 ″ and the connecting link  43 ″ rotatably mounted in the running eccentric  31  are coupled by way of an involute toothing  47 ″ to the sliding link  45 ″. If the driver  21 ″ is driven, it pivots the connecting link  43 ″ by way of the involute toothing  47 ″. As a result of the shape of the sliding link  45 ″, the end fingers of the annular spring  30  move toward one another, until the wedge segments  27  bear against one another, so that the locking effect is canceled. The running eccentric  31 , in turn, rotates without lateral force.  
         [0043]     A third modification of the first embodiment resembles the above modifications and the first embodiment except where described differently, which is why the same components are provided with the same reference numerals and similarly acting components are provided with reference numerals with three apostrophes.  
         [0044]     Due to the loading of the backrest  4  in the loading direction, one of the two wedge segments  27  is loaded less and one is loaded more. The driver  21 ′″ is linked at a coupling point  48 ′″ to a link  41 ′″, which is rotatably mounted on a connecting link  43 ′″. The connecting link  43 ′″ is configured slightly asymmetrically and comprises only one sliding link  45 ′″. Specifically described, the sliding link  45 ′″ is positioned on the side of the connecting link  43 ′″ that is proximate the wedge segment  27  which is loaded less, while on the other side, the connecting link  43 ′″ is mounted by way of the associated end finger (to the left in the drawings) of the annular spring  30  in the wedge segment  27  which is loaded more.  
         [0045]     If the driver  21 ′″ is driven, it pivots the connecting link  43 ′″ by way of the coupling point  48 ′″ and the link  41 ′″. As a result of the shape of the single sliding link  45 ′″, the associated end finger (to the right in the drawings) of the annular spring  30  pulls the wedge segment  27 , which is loaded less, to bear against the wedge segment  27  which is loaded more, so that the locking effect is canceled. The running eccentric  31 , in turn, rotates without lateral force.  
         [0046]     A second embodiment resembles the first embodiment, which is why the same components bear the same reference numerals and similarly acting components bear reference numerals which are higher by  200 . On the drive element  221  a driving segment  235  is formed on the front face with the hub  222 , which is delimited in the peripheral direction of the driver  221  by respective driving lugs  236 . The driving segment  235  grips with its driving lugs  236  with play between the narrow ends of the wedge segments  227 . The wedge segments  227  are located directly on the collar  19  of the first fitting part while the first plain bearing bushing  28 , in turn, is pressed into the second fitting part  12 .  
         [0047]     The running eccentric  231  is of annular configuration and arranged axially between the driver  221  and the wedge segments  227 . Two slots  237  that extend in the peripheral direction and axially penetrate the running eccentric  231  allow the end fingers of the annular spring  30  to penetrate, unhindered and with play, the opening jaws  229  (provided instead of the holes) of the wedge segments  227 , without coupling the wedge segments  227  to the running eccentric  231 . On the running eccentric  231 , two axially protruding pins  238  are formed on the front face facing the driver  221 . The two axially protruding pins  238  are located radially opposite one another. Each pin  238  engages positively into a hole  239  arranged in the peripheral direction. Thus, the driver  221  and the running eccentric  231  are coupled to one another fixedly in terms of rotation, i.e. coupled for rotationally fixed locking.  
         [0048]     The second plain bearing bushing  233  is pressed onto a hub-like axial projection  231   b  of the running eccentric  231  and arranged inside the collar  19 , i.e. mounted in the collar  19 . The hub  222  of the driver  221  is arranged, in turn, inside the running eccentric  231 , i.e. the driver  221  is mounted by the interposition of the running eccentric  231  with the second plain bearing bushing  233  on the first fitting  11 .  
         [0049]     During the driving, a torque is first introduced into the driver  221  and then transferred to the locking eccentric, by one of the driving lugs  236  impinging on the associated wedge segment  227  and pressing the wedge segments  227  together. By way of the holes  239  and pins  238 , the running eccentric  231  is impinged upon and driven. More specifically and due to the symmetry, the running eccentric  231  is impinged upon and driven without lateral force. The running eccentric  231  then slides with substantially the same (low) friction at each of the plain bearing bushings  28  and  233 , resulting in the rolling movement of the fitting parts  11  and  12  relative to one another.  
         [0050]     A third embodiment resembles the first and second embodiments except where described differently, which is why the same components bear the same reference numerals and similarly acting components bear reference numerals which are higher by  300  and/or  100 . The driver  321  of the third embodiment is simultaneously configured as a running eccentric and undertakes the tasks thereof, i.e. the driver and the running eccentric are configured in one piece and/or merely different regions of the same component. A driving segment  335  is formed on the driver  321 , on the front face with the hub  322 . The driving segment  335  is delimited in the peripheral direction of the driver  321  by respective driving lugs  336 . The driving segment  335  grips with its driving lugs  336  with play between the narrow ends of the wedge segments  227 .  
         [0051]     The wedge segments  227  are located directly on the collar  19  of the first fitting part, while the first plain bearing bushing  28 , in turn, is pressed into the second fitting part  12 . The second plain bearing bushing  233  is pressed onto the hub  322  of the driver  321  and arranged inside the collar  19 , i.e. mounted in the collar  19 . Two slots  337  extending in the peripheral direction and axially penetrating the driver  321  allow the end fingers of the annular spring  30  to penetrate unhindered and with play the opening jaws  229  (provided instead of the holes) of the wedge segments  227 , without at this point coupling the wedge segments  227  to the driver  321 . In a modified embodiment, precisely this coupling of the wedge segments  227  to the driver  321  could be desired, i.e. the slots  337  would be developed to form sliding links for the end fingers of the annular spring  30 , holes would be provided in the wedge segments, and the driving segment  335  would be omitted.  
         [0052]     During driving, a torque is introduced into the driver  321  and then transferred to the locking eccentric by one of the driving lugs  336  impinging on the associated wedge segment  227  and pressing the wedge segments  227  together. Due to the one-piece design, the driver  321  rotates without lateral force. It slides with substantially the same (low) friction at each of the plain bearing bushings  28  and  233 , resulting in the rolling movement of the fitting parts  11  and  12  relative to one another.  
         [0053]     It will be understood by those skilled in the art that while the present invention has been discussed above with reference to exemplary embodiments, various additions, modifications and changes can be made thereto without departing from the spirit and scope of the invention as set forth in the following claims.