Gear stage

Abstract

A gear stage ( 10 ), in particular of a vehicle seat ( 3 ), is embodied as a friction wheel gear stage. The gear stage ( 10 ) includes a housing ( 5 ), a drive ( 12 ), an output ( 14 ) that is set off from the drive ( 12 ) by an excentricity (e) and at least one sphere or another rolling body ( 15 ) for the transmission of force between the drive ( 12 ) and t he output ( 14 ). According to the invention, the position of the excentricity (e) relative to the housing ( 5 ) is arranged in a spatially fixed manner and the gear stage has at least two different direction-dependent and/or shiftable gear ratios.

1 . A gear stage of a vehicle seat, the gear stage being a friction wheel gear stage comprising:
 a housing;   at least a drive input;   at least one drive output spaced apart from the drive input by an eccentricity; and   at least one ball or some other rolling body for transmitting force between the drive input and drive output, a position of the eccentricity with respect to the housing is being spatially fixed and the gear stage having at least two different, direction-dependent or switchable transmission ratios.   
     
     
         2 . The gear stage as claimed in  claim 1 , further comprising bearings for the drive input and drive output arranged at spatially fixed points in the housing. 
     
     
         3 . The gear stage as claimed in  claim 2 , wherein the housing has different bearing stiffnesses for the bearings of the drive input and of the drive output and/or for different drive directions and/or different spatial directions. 
     
     
         4 . The gear stage as claimed in  claim 1 , wherein the ball or the other rolling body is arranged in a wedge gap between the drive input and the drive output. 
     
     
         5 . The gear stage as claimed in  claim 4 , wherein the ball or the other rolling body can move into and out of the wedge gap. 
     
     
         6 . The gear stage as claimed in  claim 4 , further comprising a pressure-exerting element comprising at least one of a spring fixed to the housing and/or a magnet, which pushes or pulls the ball or the other rolling body into a wedge gap between the drive input and drive output. 
     
     
         7 . The gear stage as claimed in  claim 6 , wherein a freewheel is formed which opens as a result of a torque introduced at the drive output by virtue of the ball or other rolling body moving out of a wedge gap between the drive input and drive output. 
     
     
         8 . The gear stage as claimed in  claim 7 , wherein a switchable clutch is formed in which the ball or other rolling body is moved out of or into a wedge gap between the drive input and drive output electrically and/or mechanically. 
     
     
         9 . The gear stage as claimed in  claim 8 , further comprising a retaining device cooperating with the pressure-exerting element for moving the ball or the other rolling body out of or into the wedge gap between drive input and drive output. 
     
     
         10 . The gear stage as claimed in  claim 8 , wherein, for moving the ball or the other rolling body out of or into the wedge gap between drive input and drive output, a control fork is provided, which can be activated externally. 
     
     
         11 . The gear stage as claimed in  claim 8 , wherein, for moving the ball or the other rolling body out of or into the wedge gap between drive input and drive output, a ball-guiding ring is provided, which guides the ball or the other rolling body, and which is in frictional contact with the drive input. 
     
     
         12 . The gear stage as claimed in  claim 4 , wherein, when the rotating movement has been finished, the drive input is rotated back by a known angle, in order to move the ball or the other rolling body out of the wedge gap between drive input and drive output. 
     
     
         13 . The gear stage as claimed in  claim 1 , wherein the drive input and/or the drive output is provided with a contour groove, within which the ball or the other rolling body runs. 
     
     
         14 . The gear stage as claimed in  claim 1 , wherein, for generating the different transmission ratios, different effective radii of the balls or of the other rolling bodies are used. 
     
     
         15 . The gear stage as claimed in  claim 1 , wherein, for generating the different transmission ratios, two different balls  15 ) and/or contours are used at the drive input and/or the drive output. 
     
     
         16 . The gear stage as claimed in  claim 13 , wherein two balls having different sizes are provided, which run in the joint groove of the drive input or the drive output for generating different transmission ratios. 
     
     
         17 . The gear stage as claimed in  claim 1 , wherein, for the transmission of force between drive input and drive output, precisely only one ball or one other rolling body is provided for every drive direction. 
     
     
         18 . The gear stage as claimed in  claim 1 , wherein, during operation, precisely only one ball or precisely only one other rolling body is in contact with both, drive input and drive output. 
     
     
         19 - 24 . (canceled) 
     
     
         25 . An actuating drive comprising:
 a housing;   a drive input;   a drive output spaced apart from the drive input by an eccentricity;   a rolling body provided for transmitting force between the drive input and drive output to form a friction wheel first gear stage, a position of the eccentricity with respect to the housing being spatially fixed and the first gear stage having at least two different, direction-dependent or switchable transmission ratios; and   a second gear stage.   
     
     
         26 . An actuating drive as claimed in  claim 25 , further comprising:
 a drive motor driving the first gear stage.   
     
     
         27 . An actuating drive as claimed in  claim 26 , wherein the drive motor and the first gear stage are arranged in said housing as a common housing. 
     
     
         28 . An actuating drive as claimed in  claim 26 , wherein the second gear stage is arranged as an upstream stage in relation to the first gear stage. 
     
     
         29 . An actuating drive as claimed in  claim 28 , wherein the drive motor, the first gear stage and the second gear stage are arranged in said housing as a common housing. 
     
     
         30 . An actuating drive as claimed in  claim 25 , further comprising:
 a vehicle seat with a seat part and a backrest, the friction wheel gear stage being connected to the vehicle seat for controlled movement of the backrest relative to the seat part.