Abstract:
A friction clutch, especially a double clutch, with a clutch housing on which at least one actuation lever is pivotally supported. A connecting member in the form of a pressure lever or an eyebolt is coupled with the actuation lever for actuation of a clutch pressure plate. The pressure lever or the eyebolt is formed as a one-piece stamped element to minimize machining and assembly costs.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a friction clutch, especially a double clutch, with a clutch housing on which is pivotally supported at least one lever that is coupled with a pressure lever for operation of a pressure plate. 
   2. Description of the Related Art 
   Conventional friction clutches are often equipped with forged pressure levers that must be machined in a costly operation. In addition, pressure levers are also utilized that are composed of several stamped elements, the assembly of which leads to increased manufacturing costs. 
   An object of the invention is therefore to produce a friction clutch, especially a double clutch, with a clutch housing on which at least one lever is pivotally supported and is coupled with a pressure lever to operate a pressure plate, wherein the pressure lever can be simply formed and economically manufactured. 
   SUMMARY OF THE INVENTION 
   The object is achieved with a friction clutch, especially a double clutch, having a clutch housing on which at least one lever is pivotally supported that is coupled with a pressure lever for actuation of a pressure plate. The pressure lever is formed as a single-piece, stamped element with a blind bore formed at one end and a throughbore at the other end, wherein the longitudinal axis of the throughbore is arranged substantially perpendicular to the longitudinal axis of the blind bore. In that way, subsequent machining, as it is necessary with forged parts, can be eliminated. 
   The stamped pressure lever is preferably formed by a descending tool so that following the forming process, and due to its own weight, the lever drops out of the tool of the press that is utilized for stamping. 
   A preferred embodiment of the friction clutch is characterized in that the blind bore is formed so that the material surrounding the blind bore is compressed. By the compression of the material surrounding the blind bore, sufficient strength is achieved without an expensive heat treatment of the pressure lever. 
   A further preferred embodiment of the friction clutch is characterized in that a thickened area is formed on the pressure lever in the region of the blind bore. By virtue of the thickened area the pressure lever is reinforced in the region of the blind bore. 
   A further preferred embodiment of the friction clutch is characterized in that a collar is formed on the pressure lever on one side in the region of the throughbore. By virtue of the formed collar the length of the throughbore is enlarged. In that way, improved support is achieved in the installed condition of the pressure lever. 
   A further preferred embodiment of the friction clutch is characterized in that the pressure lever has an offset between the blind bore and the throughbore. By means of the offset the two ends of the pressure lever have longitudinal axes that lie in a common plane, although the ends are formed differently. The longitudinal axis of the pressure lever at the end with the throughbore that is lengthened by the collar intersects the longitudinal axis at the end of the pressure lever that is thickened in the region of the blind bore. 
   The invention also relates to a friction clutch, especially a double clutch, with a clutch housing on which at least one lever is pivotally supported and which cooperates with an eyebolt for actuation of a pressure plate. 
   Conventional friction clutches are often equipped with multiple eyebolts, the individual parts of which must be expensively machined and assembled. 
   Another object of the invention is to produce a friction clutch, especially a double clutch, with a clutch housing on which is pivotally supported at least one lever that cooperates with an eyebolt for operation of a pressure plate, that has a simple design, and that can be manufactured inexpensively. 
   The object is achieved with a friction clutch, especially a double clutch, with a clutch housing on which at least one lever formed as a single-piece stamped element is pivotally supported, which cooperates with an eyebolt for operation of a pressure plate. The eyebolt is arranged with a thread formed at one end and a throughbore formed at the other end, the longitudinal axis of which is arranged substantially perpendicular to the longitudinal axis of the thread. That results in the advantage that expensive machining and assembly of individual parts can be eliminated. The stamped eyebolt is preferably formed by a descending tool so that the part falls by itself out of the tool of the press that is utilized for stamping. 
   A preferred embodiment of the friction clutch is characterized in that a collar is formed on the eyebolt on one side in the region of the throughbore. The length of the throughbore is thus enlarged by the formed collar. In that way, improved support is attained in the installed condition of the eyebolt. 
   A further preferred embodiment of the friction clutch is characterized in that the eyebolt has an offset between the thread and the throughbore. By means of the offset, the two ends of the eyebolt have longitudinal axes that lie in a common plane, although the ends are formed differently. The axis at the end of the eyebolt with the throughbore that is lengthened by the collar intersects the axis at the end of the eyebolt that is equipped with the thread. 
   A further preferred embodiment of the friction clutch is characterized in that a peripheral shoulder is formed on the eyebolt between the thread and the throughbore. The shoulder forms a stop for a spring in the installed condition of the eyebolt. 
   A further preferred embodiment of the friction clutch is characterized in that the thread is embossed on only on two opposed sides on one end of the eyebolt. The thread, which is not completely but rather only partially formed, suffices for fastening a nut securely on the end of the eyebolt. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages, features, and details of the invention will be apparent from the following description, in which various embodiments are described in detail with reference to the drawings. Thereby the features mentioned in the claims and the description, respectively, can be essential for the invention either individually or in any desired combination. In the drawings: 
       FIG. 1  is a cross-sectional view of a friction clutch with a pressure lever in accordance with the invention; 
       FIG. 2  is a perspective view of the pressure lever shown in  FIG. 1 ; 
       FIG. 3  is a side elevational view of the pressure lever shown in  FIG. 2 ; 
       FIG. 4  is a cross-sectional view taken along the line IV—IV of  FIG. 3 ; 
       FIG. 5  is an enlarged cross-sectional view of portion V of  FIG. 4 ; 
       FIG. 6  is a fragmentary cross-sectional view of the end with the blind bore as in  FIG. 3 ; 
       FIG. 7  is a view taken in the direction of arrow VII of  FIG. 3 ; 
       FIG. 8  is a view taken in the direction of arrow VIII of  FIG. 3 ; 
       FIG. 9  is a cross-sectional view of a friction clutch with an eyebolt in accordance with the invention; 
       FIG. 10  is a side elevational view of the eyebolt of  FIG. 9 ; 
       FIG. 11  is a view taken in the direction of arrow XI of  FIG. 10 ; 
       FIG. 12  is an enlarged view of portion XII of  FIG. 11 ; 
       FIG. 13  is a view taken in the direction of arrow XIII of  FIG. 10 ; 
       FIG. 14  is a view taken in the direction of arrow XIV of  FIG. 10 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A double clutch is shown in a sectional view in  FIG. 1 , the actuation system of which includes an actuation lever  1  that is pivotally supported on a housing  3  with the aid of a pin  2 . The double clutch includes a first clutch  5  and a second clutch  6 . The first clutch  5  includes a pressure plate  7  and a counterpressure plate  8 , between which a first clutch disk  9  with friction linings can be clamped. The pressure plate  7  is acted upon by a disk spring  10 , the other side of which rests against a pressure plate  11  of the second clutch  6 . A second clutch disk  13  can be clamped between the pressure plate  11  and an associated counterpressure plate (not shown). 
   A pressure lever  15  is pivotally supported on the actuation lever  1  with the aid of a pin  16 . The free end of the pressure lever  15  interacts cooperatively with a stop screw  18  that is screwed into a tapped hole  19  that is provided radially outwardly in the pressure plate  7 . The stop screw  18  is set in position in tapped hole  19  with the aid of a jam nut  20 . 
   It can be seen in  FIGS. 2 and 3  that a throughbore  22  for guiding the pin is hollowed out at one end of the pressure lever  15 . The throughbore  22  is formed in the region of an eye  23 , from which an arm  24  extends at an angle. The angle between the longitudinal axis of the arm  24  and that of the eye  23  amounts to approximately 130 to 140 degrees. At the end of the free end of the arm  24  a blind bore  26  is formed including an inclination  27 . The longitudinal axis of the blind bore  26  is coincident with the longitudinal axis of the arm  24 . The longitudinal axis of the throughbore  22  is perpendicular to the longitudinal axis of the eye  23 . In addition, the longitudinal axis of the blind bore  26  is also arranged perpendicular to the longitudinal axis of throughbore  22 . 
   One can particularly see in  FIG. 4  that an offset  30  is formed between the blind bore  26  and the throughbore  22  at an end of the eye  23 . In that context “offset” means that the pressure lever  15  does not extend in a single plane, but first extends in a first plane, then runs obliquely, and then extends in a second plane that is arranged parallel to the first plane. 
   In  FIG. 5  it can be seen that a collar  32  is formed in the region of the throughbore  22  on the eye  23 , the collar extending outwardly from one side of the eye  23 . The length of the throughbore  22  is enlarged in the axial direction by the collar  32 . 
   One can see in  FIGS. 3 and 6  that the pressure lever has a thickened area  35  at its free end in the region of the blind bore  26  and the inclination  27 . The thickened area  35  is attributable to the shaping process for producing the blind bore. 
   One can see in  FIGS. 7 and 8  that the longitudinal axes of the arm  24  and the eye  23  with the collar  32  lie in a single plane  38 . That is achieved by the offset  30 . 
   A double clutch is shown in a sectional view in  FIG. 9 , the actuation system of which includes an actuation lever  41  that is pivotally supported on a housing  43  with the aid of a pin  42 . The double clutch includes a first clutch  45  and a second clutch  46 . The first clutch  45  includes a pressure plate  47  and a counterpressure plate  48 . Between the pressure plate  47 , which is axially movable to a limited extent within the housing  43 , and the counterpressure plate  48  is a clampable clutch disk  49  with friction linings. The pressure plate  47  is contacted by a disk spring  50 , the other side of which lies against a pressure plate  51  of the second clutch  46 . The pressure plate  51  cooperates with a counterpressure plate (not shown) to clampingly engage a clutch disk  53  having friction linings. One end of an eyebolt  55  is pivotally supported on the actuation lever  41  with the aid of a pin  56 . The other end of the eyebolt  55  is fastened with the aid of a nut  59  on a projection  58  on the pressure plate  51 . A compression coil spring  62  is clamped between the projection  58  of the pressure plate  51  and a shoulder  64  that is formed on the eyebolt  55 . 
   In  FIG. 10  there is shown a throughbore  66  that is hollowed out on one end of the eyebolt  55  for the pin  56 . The throughbore  66  is surrounded by an eye  67  that turns into a base  68 . The base  68  is slightly angled in relation to the eye  67  and widens toward the shoulder  64 . A stud  70  having three axial sections  71 ,  72 , and  73  with different outer diameters extends from the base  68 . The section  71  has the largest and section  73  has the smallest outer diameter. A thread  75  is formed on the outside of section  73 . 
   In  FIG. 11  one can see that an offset  76  is formed in the transition region between the eye  67  and the base  68 . In that context “offset” means that the base  68  extends in a plane that is arranged parallel to and spaced from a plane in which the eye  67  extends. The eyebolt  55  has a curved form in the transition region at the offset  76 . 
   In  FIG. 12  one can see that a collar  78  is formed in the region of the throughbore  66  on one side of the eye  67 . The length of the throughbore  66  is increased by the collar  78 . 
   In  FIG. 13  one can see that the thread  75  does not extend over the entire periphery of the axial section  73 , but is merely stamped on two opposite sides. The two-sided stamping of the thread nonetheless suffices to ensure a secure fastening of the associated nut. 
   In  FIG. 14  one can see that the formation of the collar  78  in the region of the throughbore is compensated by the offset  76 , so that the eyebolt  55  has a common axis  80 . 
   The double clutches shown in  FIGS. 1 and 9  are provided with different reference numbers. It should be pointed out that the double clutches shown in  FIGS. 1 and 9  can be one and the same clutch, which can be equipped with an eyebolt  55  as it is shown in  FIGS. 10 through 14 , as well as with a pressure lever  15  as it is shown in  FIGS. 2 through 8 . 
   Although particular embodiments of the present invention have been illustrated and described, it would be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit of the present invention. It is therefore intended to encompass within the appended claims all such changes and modifications that fall within the scope of the present invention.