Abstract:
A pedal assembly having an assistance device. In some implementations the assistance device comprises a profile fixed to the arm of a pedal, the arm of the pedal being pivotally coupled to a support. The profile includes an elongate curved surface that is acted upon by a spring-actuated lever attached to the support. In operation as the pedal arm is moved between a rest position and one or more active positions, the lever applies a force to the arm through the profile by acting upon on one or more portions of the elongate curved surface, the direction of the force applied to the arm being dependent upon the portion of the elongate curved surface being acted upon by the lever.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application relates to and claims the benefit and priority to Spanish Patent Application No. P201230068, filed Jan. 18, 2012. 
       FIELD 
       [0002]    The present invention relates to an assistance device for operating a pedal of a motor vehicle and to a pedal comprising the assistance device. 
       BACKGROUND 
       [0003]    Pedals comprising assistance devices which aid in improving the effort which a driver must exert on the shoe of a pedal for operating a servobrake or a clutch are known in the automotive industry. 
         [0004]    U.S. Publication No. 2005/0252334A1 describes a clutch pedal assembly comprising a spring and a cam fixed to a support on which the pedal acts, such that the cam, having a specific profile, compresses the spring during the stroke of the pedal. 
         [0005]    European Publication No. EP480602A1 describes a pedal having an arm, the end of which presses a leaf spring element as it moves between the resting position and the clutch or active position. 
         [0006]    Spanish Patent No. ES20205415T3 describes an assistance device comprising a profile integral with the pedal and delimited by an angular sector cooperating with a rolling means suitable for moving according to a substantially horizontal direction through the action of an elastic means. 
       SUMMARY OF THE DISCLOSURE 
       [0007]    According to some implementations an assistance device is provided that comprises a profile coupled to an arm of the pedal, elastic means coupled to a support of the pedal and rolling means acting on the profile operated by the elastic means, exerting additional force on the arm of the pedal, between a resting position of the pedal and an active position of the pedal. The assistance device further comprises a lever which is arranged pivotally coupled to the support and at one of the ends of which the rolling means and the elastic means are coupled. 
         [0008]    The elastic means exert stress on the lever, the stress being transmitted through the rolling means against the profile. The arrangement of the elastic means with respect to the rolling means reduces, or otherwise minimizes contact forces among the various components to reduce friction that can result in high hysteresis which can be seen in the force necessary for moving the pedal. 
         [0009]    The configuration of the assistance device also reduces the number of necessary elements. 
         [0010]    These and other advantages and features will be more evident in view of the figures and the detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  shows a perspective view of a pedal assembly of a motor vehicle with an assistance device according one implementation. 
           [0012]      FIG. 2  shows another perspective view of the pedal assembly shown in Figure 
           [0013]      FIG. 3  shows an exploded view of the pedal assembly shown in  FIG. 1 . 
           [0014]      FIG. 4  shows a side view of the pedal assembly shown in  FIG. 1  in an initial or resting position. 
           [0015]      FIG. 5  shows a side view of the pedal assembly shown in  FIG. 1  in a position with zero assistance force. 
           [0016]      FIG. 6  shows a side view of the pedal assembly shown in  FIG. 1  in a position with maximum assistance force. 
           [0017]      FIG. 7  shows a side view of the pedal assembly shown in  FIG. 1  in a position with residual assistance force. 
           [0018]      FIG. 8  shows a diagram of the force generated on a shoe of the pedal assembly shown in  FIG. 1  according to one implementation. 
           [0019]      FIG. 9  shows a perspective view of a profile according to one implementation. 
           [0020]      FIG. 10  shows a section of the profile shown in  FIG. 9  according to plane IX. 
           [0021]      FIG. 11  shows a perspective view of a profile according to another implementation. 
           [0022]      FIG. 12  shows a section of the profile shown in  FIG. 11  according to plane XII 
           [0023]      FIG. 13  shows a diagram of the force generated on a shoe of the pedal assembly shown in  FIG. 1  with the profile shown in  FIG. 11 . 
           [0024]      FIG. 14  shows a perspective view of a profile according to another implementation. 
           [0025]      FIG. 15  shows a section of the profile shown in  FIG. 14  according to plane XIV. 
           [0026]      FIG. 16  shows a diagram of the force generated on a shoe of the pedal shown in  FIG. 1  with the profile shown in  FIG. 14 . 
           [0027]      FIG. 17  shows a perspective view of a profile according to another implementation. 
           [0028]      FIG. 18  shows a section of the profile shown in  FIG. 17  according to plane XVII. 
           [0029]      FIG. 19  shows a diagram of the force generated on a shoe of the pedal shown in  FIG. 1  with the profile shown in  FIG. 17 . 
       
    
    
     DETAILED DESCRIPTION 
       [0030]      FIGS. 1 to 7  show a clutch or brake pedal  1  adapted to a motor vehicle which comprises a support  20 , an arm  13  pivotal with respect to the support  20 , and a shoe  14  arranged at one end of the arm  13 , operable by a user. The pedal  1  further comprises a non-depicted actuating rod which is arranged coupled to the arm  13  through a coupling  15  and which transmits an activation force F,F′,F″ exerted on the shoe  14  by the driver, to a non-depicted actuator, primarily a servobrake or a clutch. 
         [0031]    According to one implementation the pedal  1  comprises a shaft  50  through which the arm  13  is coupled to the support  20 , the shaft  50  traversing the support  20  through holes  21 , shown in  FIG. 3 , and an end  11  of the arm  13 , the arm  13  being pivotal between an initial or resting position shown in  FIG. 4  and a final active position or a position with the operated pedal shown in  FIG. 7 . 
         [0032]    The pedal  1  comprises an assistance device  10  which cooperates in transmitting force to the actuator via the arm  13  such that from a position of the arm  13  with respect to the support  20 , called a position with zero force shown in  FIG. 5  and depicted by means of point B in a diagram of force/movement shown in  FIG. 8 , the activation force F′ which must be exerted by the driver on the shoe  14  to further move the arm  13  and operate the actuator is less than the force which would have to be exerted if the pedal  1  did not include the assistance device  10 . 
         [0033]    The assistance device  10  is arranged articulated to the arm  13  and to the support  20 . The assistance device  10  comprises a profile  30  coupled to the arm  13 , elastic means  35  coupled to the support  20 , rolling means  45 , 46  adapted for contacting profile  30  and a lever  40  which is arranged pivotally coupled to the support  20  and at one of the ends of which the rolling means  45 , 46  and the elastic means  35  are coupled. The rolling means  45 , 46  act on the profile  30  pressed by the lever  40  which is in turn operated by the elastic means  35  exerting additional force on the arm  13  during the stroke of the arm  13  between the resting position and the active position. 
         [0034]    The lever  40  comprises two sets of substantially parallel surfaces  41 , 43  at each end. The lever  40  includes a coupling  42  extending from each surface  41  in a manner substantially orthogonal to the parallel surfaces  41  at one of the ends. The coupling  42  extends outwardly from the lever  40 . In the implementations shown in the figures, the coupling  42  has a substantially cylindrical geometry. 
         [0035]    The support  20  in turn comprises two substantially parallel walls  24  each of which comprises a housing  22 , 23  wherein the respective coupling  42  of the lever  40  is housed, configuring a pivoting attachment between the lever  40  and the support  20 . The housing  22 , 23  comprises a first part  23  with a substantially circular section and a second part  22  continuous to the first part  23 , communicating the first part  23  with the outside, allowing the insertion of the coupling  42  in the first part  23 . The second part  22  has a width less than the diameter of the first part  23 , allowing, on one hand, easily inserting the coupling  42  in the first part  23  and on the other hand, preventing the coupling  42  from being easily released from the support  20  once the lever  40  is coupled to the support  20 . 
         [0036]    According to some implementations the lever  40  comprises, at the opposite end, a projection  44  which is arranged fixed on one of the parallel surfaces  43  arranged at said opposite end and through which the free end of the lever  40  is fixed to the support  20  through the elastic means. In the implementation shown, the projection  44  is substantially disc-shaped. 
         [0037]    In some implementation the elastic means comprises a spring  35 , one of the ends  36  of which is arranged fixed to the support  20  and the other end  37  to the lever  40 . In the implementation shown, the spring  35  is a helical spring, in other implementations other elastic means may be used. In the implementations shown in the figures, the ends  36 , 37  of the spring  35  are substantially hook-shaped, being inserted in grooves  25   b , 44   b  arranged respectively in an extension  25  of the support  20  and in the projection  44  coupled to the lever  40 . The grooves  25   b , 44   b  extend perimetric to the extension  25  of the support  20  and to the projection  44 . The spring  35  is arranged forming an angle with respect to the lever  40 , said angle being in some implementations as close as possible to 90°, such that the spring  35  is prevented from generating high radial compression forces in the lever  40 , which may cause reactions and therefore friction in the coupling of the end  42  of the lever with the support  20 . 
         [0038]    According to some implementations the rolling means comprises a wheel  45  which is arranged in contact with a rolling surface  32  of the profile  30  during the movement of the arm  13 . The rolling means may comprise at least one stop element  46  which extends continuously from a face of the wheel  45  and which laterally guides the movement of the wheel  45  along the rolling surface  32  together with a guide surface  33  of the profile  30 , preventing the accidental decoupling of the wheel  45  with respect to the rolling surface  32 . According to some implementations the stop element  46  is disc-shaped and is arranged coaxial to the wheel  45 . 
         [0039]    In the implementations shown in the figures, the rolling means comprises two stop elements  46  each of which extends continuously from a face of the wheel  45  and coaxial to the wheel  45 . Likewise, the profile  30  comprises two guide surfaces  33  each of which extends continuously from the rolling surface  32 . The two guide surfaces  33  are arranged substantially parallel to one another and substantially orthogonal to the rolling surface  32 , as shown in  FIG. 10 . 
         [0040]    The projection  44  is arranged substantially coaxial to the rolling means. Therefore, the force exerted by the elastic means  35  is successfully transmitted as directly as possible to the rolling surface  32 , reducing losses by friction. 
         [0041]      FIGS. 4 to 7  show the pedal  1  in different positions each of which corresponds respectively with points A, B, C and D depicted in  FIG. 8  showing the reaction force generated by the assistance device  10  on the shoe  14  depending on the movement of the arm  13  of the pedal  1 . 
         [0042]    Therefore, the pedal  1  first starts from an initial position shown in  FIG. 4  in which the spring  35  pulls the lever  40  such that the lever  40  exerts pressure on the wheel  45  against the rolling surface  32  of the profile  30  integral with or otherwise removably coupled to the arm  13  of the pedal  1 . From this position, depicted in  FIG. 8  by means of point A, and to the position with zero force shown in  FIG. 5  and depicted in  FIG. 8  by means of point B, the driver must exert a progressive force F on the shoe  14  in order to operate the actuator. During the stroke between both positions, the force F exerted on the shoe  14  must be greater than the case in which the pedal  1  does not include an assistance device  10  because it must overcome the moment generated by the force F 1  exerted by the wheel  45  on the profile  30 . 
         [0043]    In the position with zero force shown in  FIG. 5 , the assistance device  10  does not exert any reaction on the arm  13  of the pedal  1 , the force F′ exerted by the driver on the shoe  14  being similar to the case in which the pedal  1  does not include an assistance device  10  because the force F 2  exerted by the wheel  45  on the profile  30  does not generate reaction in the shoe  14 . 
         [0044]      FIG. 6  shows the pedal  1  in a position with maximum reaction force which corresponds with point C of  FIG. 8 . Therefore, from the position with zero reaction force to the position with maximum reaction force, the driver must exert a force F″ on the shoe  14  in order to operate the actuator, the force F″ being less than the force which must be exerted by the driver in the event that the pedal  1  does not include the assistance device  10  because the force F 3  exerted by the wheel  45  on the profile  30  generates a reaction favoring the movement of the shoe  14 . 
         [0045]    Finally,  FIG. 7  shows the pedal  1  in a position with residual reaction force which corresponds with point D of  FIG. 8 . From the position with maximum reaction force, the driver must exert a force F″′ on the shoe  14  in order to operate the actuator, the force F″′ being gradually greater than the force F″ which must be exerted in the position with maximum reaction force but less than the force which must be exerted in the event that the assistance device  10  is not included because the force F 4  exerted by the wheel  45  on the profile  30  generates a reaction favoring the movement of the shoe  14 , even though it is less than that in the preceding movement. 
         [0046]    The rolling surface  32  of the profile  30  has a curved trajectory suitable for generating forces F 1 , F 2 , F 3  and F 4  for a desired operation of the assistance device  10 . 
         [0047]    Different profiles  30 ; 60 ; 70 ; 80  such as those shown in  FIGS. 8 to 19  with their respective characteristic curves, can be used for different types of vehicles and drives depending on the operation requirements of the pedal  1 . Different performances of the pedal  1  adapted to each individual vehicle/drive can thus be obtained by just replacing the profile  30 ; 60 ; 70 ; 80 , keeping the rest of the parts common. In the implementation shown in  FIGS. 14 to 16 , the assistance device  10  acts before the assistance device  10  of  FIGS. 4 to 8  so that the maximum reaction force of the assistance device  10  is obtained in a shorter stroke of the arm  13 , whereby the driver can tell sooner that he/she must exert less effort on the shoe  14  and in the final sector of the stroke of the arm  13 , the assistance device  10  does not act in a manner which can be perceived by the user, which can be beneficial in certain vehicles and drives. 
         [0048]      FIGS. 11 to 13  show an implementation of the profile  60  of the assistance device  10  which is characterized in that, throughout the entire stroke of the arm  13 , the force exerted by the driver on the shoe  14  is greater than that which would be necessary if the pedal  1  did not include an assistance device  10 . The assistance device  10  comprising the profile  60  causes said arm  13  to tend to return to the resting position throughout the entire stroke of the arm  13 . 
         [0049]      FIGS. 17 to 19  show another implementation of the profile  80  of the assistance device  10  in which the force exerted by the driver on the shoe  14  is greater than that which would be necessary if the pedal  1  did not include an assistance device  10  only throughout a first sector of the stroke of the arm  13 , whereas subsequently, the assistance device  10  does not act in a manner which can be perceived by the user. 
         [0050]    In order to obtain an optimized, readily interchangeable pedal  1 , the pedal  1  can be adapted to any requirement for use by modifying the profile. To that end, the pedal  1  may comprise a profile  30 ; 60 ; 70 ; 80  which is arranged removable to the arm  13  of the pedal  1 , said profile  30 ; 60 ; 70 ; 80  being readily interchangeable. To that end, the profile  30 ; 60 ; 70 ; 80  may comprise a housing  34 ; 64 ; 74 ; 84  collaborating with a projection  12  protruding from the arm  13  of the pedal  1  for fixing the profile  30 ; 60 ; 70 ; 80  to the arm  13 . The projection  12  shown in  FIG. 3  has a substantially T-shaped cross-section. The projection  12  may comprise a first substantially rectangular part  12   a,  defined by width d 1 , extending continuously to the arm  13  and a second part  12   b  with a substantially rectangular section defined by width d 2  and continuous to the first part  12   a.  The width d 1  of the first part  12   a  is less than the width d 2  of the second part  12   b.  The housing  34 ; 64 ; 74 ; 84  of the profile  30 ; 60 ; 70 ; 80  extends longitudinally along the profile  30 ; 60 ; 70 ; 80 , communicating with the outside through a groove  31 ; 61 ; 71 ; 81  having a width d 3 ;d 3 ′;d 3 ″;d 3 ″′, shown in  FIGS. 9 ,  12 ,  15  and  18 , greater than the width dl of the first part  12   a  of the projection  12 . The housing  34 ; 64 ; 74 ; 84  has a substantially rectangular section defined by width d 4 ;d 4 ′;d 4 ″;d 4 ″′ such that the second part  12   b  of the projection  12  is tightly housed in the respective housing  34 ; 64 ; 74 ; 84 . 
         [0051]    Elements  62 ; 72 ; 82  correspond in a like manner to element  32  described above. Elements  63 ; 73 ; 83  correspond in a like manner to element  33  described above.