Patent Publication Number: US-6212970-B1

Title: Pedal assembly with adjustable pad

Description:
TECHNICAL FIELD 
     The subject invention relates to an adjustable pedal assembly of the type attached to an automotive vehicle to control the brake, clutch and/or throttle in normal operation but which can be adjusted to a different position to accommodate a different driver position. 
     BACKGROUND OF THE INVENTION 
     Pedal assemblies are provided in vehicles to control brakes, engine throttles, and/or clutches. Typically, these pedals include a lever arm pivotally mounted to a mounting bracket and a pedal pad mounted to a lower end of the lever arm. These pedals are foot operated by the driver. In order for the driver to maintain the most advantageous position for working the control pedals, the vehicle front seat is usually slidably mounted on a seat track and can be moved forwardly or rearwardly between several adjusted positions. 
     The adjustment provided by moving the seat does not accommodate all vehicle drivers due to differences in anatomical dimensions. Another concern involves the placement of a vehicle driver too close to the steering wheel when the seat is adjusted in a forward position, which could result in injury to a driver from an exploding airbag. Further, some vehicles do not have seats with seat tracks and thus, require another method for placing the pedals in the most advantageous position for the driver. 
     Various proposals have been made to provide selective adjustment of pedal positions to accommodate various size drivers. Selective pedal adjustment can be accomplished by moving the entire lever arm in forward and rearward directions, or can be accomplished by moving the pedal pad in forward and rearward directions with respect to the lever arm. Examples of an adjustable pedal assemblies are shown in U.S. Pat. Nos. 3,151,499 to Roe, 3,563,111 to Zeigler, and 3,643,524 to Herring. Adjustable pedal assemblies are often complex, difficult to package, and expensive. Additionally, they can be difficult to assemble and operate. 
     Thus, it would be desirable to have a simplified adjustable pedal assembly that is less expensive, easy to operate, requires less packaging space, and which is easily assembled. 
     SUMMARY OF THE INVENTION AND ADVANTAGES 
     An adjustable pedal assembly includes a mounting bracket for attachment to a vehicle structure and a pedal lever having an upper end and a lower end. The upper end of the pedal lever is pivotally supported with respect to the mounting bracket. The assembly also includes a pedal pad that is connected to the lower end of the pedal lever and a driving mechanism that is operative to move the pedal pad between an extended position and a retracted position. The assembly is characterized by including a control linkage interconnecting the driving mechanism and the pedal pad wherein the driving mechanism drives the control linkage along a guide path defined by the pedal lever to move the pedal pad between the extended and retracted positions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
     FIG. 1 is a side view of the subject adjustable pedal assembly as installed in a vehicle. 
     FIG. 2 is side view of the subject adjustable pedal assembly in the fully retracted position. 
     FIG. 3 is a side view of the adjustable pedal assembly of FIG. 1 in the fully extended position. 
     FIG. 4 is a perspective view of the assembly shown in FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a vehicle is shown generally at  10  in FIG.  1 . The vehicle includes an adjustable pedal assembly shown generally at  12 . The adjustable pedal assembly includes a mounting bracket  14  that is attached to a vehicle structure  16  as is known in the art. A pedal lever  18  is pivotally mounted with respect to the bracket  14  such that a vehicle driver can move the lever  18  from a rest position to an applied position. Typically, the lever  18  is mounted to the bracket  14  on a pivot shaft  20 , however, other mounting methods known in the art could also be used. 
     The pedal lever  18  includes an upper end  22  and a lower end  24 . A pedal pad  26  is connected to the lower end  24  of the pedal lever  18 . The driver applies his foot against the pedal pad  26  to move the lever  18  from the rest to the applied position. The lever  18  is typically connected to a vehicle control system (not shown) such as the braking, engine throttle, or clutch system. This control connection can be accomplished mechanically with cables, or can be done electronically. 
     As shown in FIG. 2, the pedal assembly  12  includes a driving mechanism  28  that is operative to adjust the position of the pedal pad  26  between an extended position and a retracted position. A control linkage assembly, shown generally at  30 , interconnects the driving mechanism  28  and pedal pad  26 . The driving mechanism  28  drives the control linkage assembly  30  along a guide path that is defined by the pedal lever  18  to move the pedal pad  26  between the extended and retracted positions. FIG. 2 shows the pedal pad  26  in a fully retracted position and FIGS. 3 and 4 show the pedal pad  26  in a fully extended position. 
     As shown in FIGS. 2 and 3, the driving mechanism  28  is preferably mounted to the lever  18  and includes a drive nut  32  and a screw shaft  34 . A drive motor  36  (see FIG. 1) is used to drive the screw shaft  34 , which causes the nut  32  to move up and down the shaft  34 . The lever  18  includes a smooth guide rod portion  38  that defines the guide path. The guide rod portion  38  extends along the length of the lever  18 . The drive nut  32  includes a smooth bore  40  that slidably receives the guide rod portion  38  and a threaded bore  42  that engages the externally threaded surface of the screw shaft  34 . 
     The screw shaft  34  is preferably mounted such that it is parallel to the guide rod portion  38 . A support plate  44  mounts one end of the screw shaft  34  to the lever  18  and provides additional support for the shaft  34 . A wire connection  46  extends from the screw shaft  34  to the motor  36 . 
     As the motor  36  rotates the screw shaft  34 , the drive nut  32  is driven up and down the guide rod portion  38  of the lever  18 . As the nut  32  moves from an upper position, shown in FIG. 2, to a lower position, shown in FIG. 2, the control linkage assembly  30  extends the pedal pad  26  outwardly, away from the lever  18 . Thus, as the nut  32  is driven in a generally vertical direction, the pedal pad  26  is adjusted in a generally horizontal direction. 
     As shown in FIG. 4, the control linkage assembly  30  is comprised of a plurality of link members. The control linkage assembly  30  includes a first linkage assembly  48  and a second linkage assembly  78 . The first linkage assembly  48  includes a first link member  52  and a second link member  54 . The first link member  52  has one end  56  that is fixed to the pedal pad  26  at a first connection  58  and another end  60  that is fixed to the drive nut  32  at a second connection  62 . The second link member has one end  64  that is movably supported with respect to the pedal pad  26  at a third connection  66  and another end  68  that is fixed to a lower end  24  of the pedal lever  18  at a fourth connection  70 . 
     The first  52  and second  54  link members are pivotally connected to each other at a fifth connection  72  that is between the lever  18  and the pedal pad  26 . Preferably, the fifth connection  72  is positioned between the first  58  and second  52  connections and between the third  66  and fourth  70  connections. The fifth pivotal connection  72  between the link members  52 ,  54  creates a scissor type motion when the drive nut  32  is driven up and down the screw shaft  34 . To create this scissors motion, the fourth connection  70  remains fixed and the first  58 , second  62 , and third  66  connections move relative to the fourth connection  70 . The second connection  62  moves only in a linear direction up and down the guide rod portion  38 . The first connection  58  rotates about the second connection  72  and the third connection  66  rotates about the fourth connection  70 . 
     The pedal pad  26  includes at least one slot  74  that receives a guide pin  76  to form the third connection  66 . The drive motor  36  rotates the screw shaft  34  causing the drive nut  32  to move downwardly along the lever  18 . As the nut  32  moves downwardly it also moves the first link member  52  downwardly causing the pedal pad  26  to extend. As the pedal pad  26  extends, the end  64  of the second link member  54  that is connected to the guide pin  76  slides downwardly in the slot  74  until it reaches the bottom of the slot  74  and the pedal pad  26  is in the fully extended position. 
     The control linkage assembly  30  also preferably includes a second linkage assembly  78  that is comprised of basically the same components as the first linkage assembly  48 . The first linkage assembly  48  is mounted on one side of the pedal lever  18  and the second linkage assembly  78  is mounted on an opposite side of the pedal lever  18 . The linkage assemblies  48 ,  78  work in unison to move the pedal pad  26  between the fully retracted and extended positions. The pedal pad  26  includes a corresponding slot  74  in the opposite side of the pedal pad  26  and the guide pin  76  extends between the first ends  64  of the second link members  54  of each linkage assembly  48 ,  78 . While two linkage assemblies  48 ,  78  are preferred, it should be understood that the pedal pad  26  could also be adjusted with a single linkage assembly. Two linkage assemblies are preferred to provide sufficient support for the pedal pad  26 . 
     The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. 
     Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, wherein reference numerals are merely for convenience and are not to be in any way limiting, the invention may be practiced otherwise than as specifically described.