Patent Publication Number: US-2018050671-A1

Title: Sliding-type heel pad with height adjustment function

Description:
BACKGROUND AND SUMMARY 
     The present invention relates to a sliding-type heel pad with height adjustment function. 
     Trucks, available as large- or medium-sized vehicles, have a raised portion at the back of a floor panel that constitutes a cabin above the front wheels, and seats for a driver and a passenger are on the raised portion. A driver, of average body size, driving such a truck can sit in the seat with feet on the floor panel or can step down on (depress) an accelerator or brake pedal by toes while keeping the heel on the floor panel. On the other hand, a driver, of smaller than the average body size, driving such a truck sits in the seat with only the toes on the floor panel. During driving, the driver has to step on the accelerator or brake pedal by the toes with the heels away from the floor panel. Accordingly, it is difficult for a driver of smaller than the average body size to drive keeping oneself in an optimum, comfortable posture. 
     As a solution to the above problem, some devices (systems) are devised to, upon adjusting the seat position, for example, adjust the positions of the accelerator pedal and brake pedal, as well as adjust the position or height of the panel that the driver&#39;s heel touches when the driver steps on the accelerator or brake pedal (see Patent. Document 1). Besides the above solution, it is also devised to provide the floor panel with a heel pad that allows a driver to step on the accelerator or brake pedal with the heel on the pad. 
     REFERENCE DOCUMENT LIST 
     Patent Document 1: Japanese Patent No. 4479233 
     For example, the system disclosed in Japanese Patent No. 4479233 can adjust the position of the pedal or panel together with the positional alignment of the seat, whereby a driver can assume the optimum posture regardless of body size. This configuration is convenient but is complicated. Also, large- or medium-sized vehicles such as a truck have limits in positional alignment of the seat compared with any common type of vehicle. This makes it difficult to apply to such a vehicle the system of Patent Document 1 that adjusts the position of the pedal or panel together with the positional alignment of the seat. 
     On the other hand, the heel pad placed on the floor panel is advantageous in terms of its simpler configuration and lower installation costs than the device of Patent Document 1. Consider the case of installing a heel pad of such height as ensures a driver A of smaller than the average body size can put the heel on the panel while touching the toes with the pedal. In this case, as shown in  FIG. 13 , the driver A of smaller than the average body size can step on a pedal  102  with the heel on a heel pad  101  placed on a floor panel  100  and thus can drive in a comfortable posture. Regarding a driver B of average or larger body size, however, when the heel touches the heel pad  101 , the knee is raised by the thickness (height) of the heel pad  101  and bent sharply compared with when the heel touches the floor panel  100 . Hence, in case the driver B of average or larger body size drives the vehicle, it is more likely that the driver has to step on the pedal with the heel on the heel pad  101  in an uncomfortable posture. 
     It is desirable to provide a sliding-type heel pad with height adjustment function that ensures a driver can drive a vehicle in an optimum posture regardless of body size. 
     The sliding-type heel pad with height adjustment function according to an aspect of the present invention is characterized by including: a pad main body having an upper surface that varies in height from a floor panel inside a vehicle cabin depending on a position at which a driver touches the pad main body by heel; a sliding mechanism for moving the pad main body toward or away from a pedal disposed inside the cabin; and a stopper mechanism for restricting movement of the pad main body by the sliding mechanism. 
     Furthermore, the sliding-type heel pad is characterized by further including an operation part that allows the stopper mechanism to operate so as to cancel the restriction on the movement of the pad main body by the sliding mechanism. 
     In this case, the operation part is preferably an operation button that is disposed on the pad main body and depressed by the driver&#39;s foot. 
     Also, the operation part is preferably an operation lever that is oscillatably attached to the pad main body and pushed down by the driver&#39;s foot. 
     Furthermore, the sliding-type heel pad is characterized in that the upper surface of the pad main body is preferably a surface that gradually decreases in height from the floor panel from the pedal side to the driver&#39;s seat side. 
     In this case, the upper surface of the pad main body is preferably a step-like surface that is a combination of at least two or more surfaces at different heights from the floor panel. 
     According to an aspect of the present invention, a driver can chive a vehicle in an optimum posture, regardless of body size. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an explanatory view showing leg conditions when the heel touches a footboard at a smaller height from a floor panel in a sliding-type heel pad according to an embodiment of the present invention. 
         FIG. 2  is an explanatory view showing leg conditions when a driver D of smaller than the average body size puts the heel on the footboard at a smaller height from the floor panel in the sliding-type heel pad according to an embodiment of the present invention. 
         FIG. 3  is a perspective view showing an example of the sliding-type heel pad according to an embodiment of the present invention. 
         FIG. 4  is an exploded perspective view showing an example of a sliding mechanism and stopper mechanism. 
         FIG. 5A  is an exploded sectional view showing the configuration of an operation button and its surroundings,  FIG. 5B  is a sectional view showing the operation button in a first position and its surroundings, and  FIG. 5C  is a sectional view showing the operation button in a second position and its surroundings. 
         FIG. 6  is a perspective view showing the sliding mechanism when the operation button is in the first position. 
         FIG. 7  is a partial sectional view showing a swinging member when the operation button is in the first position. 
         FIG. 8  is a perspective view showing the sliding mechanism when the operation button is in a second position. 
         FIG. 9  is a partial sectional view showing the swinging member when the operation button is in the second position. 
         FIG. 10  is an exploded perspective view showing the configuration of the sliding-type heel pad with a foot lever. 
         FIG. 11  is a perspective view of a sliding-type heel pad when the stopper mechanism functions. 
         FIG. 12  is a perspective view of a sliding-type heel pad when the stopper mechanism does riot function. 
         FIG. 13  shows leg conditions when a driver A of smaller than the average body size or driver B of average body size steps on a pedal using a heel pad with the same height from the floor panel. 
     
    
    
     DETAILED DESCRIPTION 
     A sliding-type heel pad according to the present invention will be described below. A large- or medium-sized vehicle, typically, a truck (hereinafter referred to as ‘vehicle’) has a cabin above front wheels. As shown in  FIG. 1 , a floor panel  10  that forms the floor of the cabin is raised upward at the back of the cabin. The raised portion constitutes a housing for the front wheels. A seat  11  is placed on the raised portion of the floor panel  10 . The seat  11  includes a seat portion  11   a  and a backrest  11   b  and allows positional alignment of the seat portion  11   a  in the front-back direction (X direction) and angle adjustment for the backrest  11   b.    
     A pedal  14 , such as an accelerator or brake pedal, is disposed above the floor panel  10  as well as near a dashboard lower panel (dashboard panel)  13 . Also, the floor panel  10  is provided with a sliding-type heel pad  15 . 
     The sliding-type heel pad  15  slidably moves toward the pedal  14  (X direction) or away from the pedal  14  (−X direction) so as to adjust at two levels the height of a footboard on which a driver puts the heel. For example, when a driver C of average or larger body size drives the vehicle, the position of the sliding-type heel pad  15  is adjusted so that the driver can put the heel on a footboard  15   b  at a smaller height from the floor panel  10  out of footboards  15   a,    15   b  of the sliding-type heel pad  15 . 
     On the other hand, if the driver D of smaller than the average body size steps on the pedal  14 , trying to put the heel on the footboard  15   b  at a smaller height from the floor panel  10  out of the footboards  15   a,    15   b  of the sliding-type heel pad  15 , the heel cannot touch there dangling in the air (as indicated by double-dashed line in  FIG. 1 ). Thus, as shown in  FIG. 2 , in case a driver D of smaller than the average body size drives, the position of the sliding-type heel pad  15  is adjusted so that the driver can put the heel on the footboard  15   a  at a larger height from the floor panel  10  out of the footboards  15   a,    15   b  of the sliding-type heel pad  15 . 
     As shown in  FIGS. 3 and 4 , the sliding-type heel pad  15  includes a pad main body  20 , a sliding mechanism  21 , a stopper mechanism  22 , and an operation button  23 . The pad main body  20  has a two-step upper surface that is a combination of two upper surfaces  20   a,    20   b  at different heights from the floor panel  10 . Here, the upper surface  20   a  forms the footboard  15   a  on which a driver of smaller than the average body size puts the heel during driving. Also, the upper surface  20   b  forms the footboard  15   b  on which a driver of average or larger body size puts the heel during driving. These upper surfaces  20   a,    20   b  are set on the pedal  14  side and on the seat  11  side, respectively. 
     The height from the floor panel  10  to the upper surface  20   a  and the height from the floor panel  10  to the upper surface  20   b  are obtained based on experiments, statics, etc. To give an example, the height from the floor panel  10  to the upper surface  20   a  is set to, for example, 45 mm, and the height from the panel  10  to the upper surface  20   b  is set to, for example, 15 mm. 
     In the above example, the upper surface of the floor panel  10  has a two-step form, but it only has to reduce its height from the pedal-side end to the seat-side end. In other words, the upper surface of the floor panel  10  may have a step-like form of, for example, three or more levels or alternatively may form the surface inclined or curved downward from the pedal  14  side to the seat  11  side. 
     The sliding mechanism  21  and the stopper mechanism  22  are disposed below the pad main body  20 . Conceivable examples of the sliding mechanism  21  include two pairs of rails, i.e., rail pairs  25 ,  26  provided at opposite ends of the pad main body  20  in the width direction (Y direction). The rail pair  25  includes a panel-side rail  27  fixed to the floor panel  10  and, a pad-side rail  28  fixed to the underneath of the pad main body  20 . The panel-side rail  27  is, for example, a rail open at its upper surface. At the upper end of a side wall  27   a  of the panel-side rail  27 , plural locking pieces  30  are provided at regular intervals along the longitudinal direction (X direction) of the panel-side rail  27 . 
     The pad-side rail  28  is, for example, a rail open at its lower surface and its opposite end surfaces in the longitudinal direction. The pad-side rail  28  has an opening  28   c  that is formed at substantially the center in the longitudinal direction (X direction) over a region from the upper surface  28   a  to the side, surface  28   b.  When the panel-side rail  27  is inserted into the pad-side rail  28 , the opening,  28   c  exposes some of the locking pieces  30  of the panel-side rail  27 . 
     The opening  28   c  receives an engagement piece  45  of a swinging member  40  constituting the stopper mechanism  22 , as described below. Once the engagement piece  45  of the swinging member  40  has been inserted therein, engagement holes  46  formed in the engagement piece  45  engage with the locking pieces  30  exposed from the opening  28   c.    
     The aforementioned side surface  28   b  of the pad-side rail  28  is equipped with a rib  28   d  for oscillatably holding the swinging member  40 , and a pin  28   e  that comes into contact with one end of a coil spring  31  attached to the rib  28   d.  The coil spring  31  depresses the swinging member  40  toward the R 1  direction of  FIG. 7 . 
     Similar to the rail pair  25 , the rail pair  26  includes a panel-side rail  33  fixed to the floor panel  10  and a pad-side rail  34  fixed to the underneath of the pad main body  20 . The panel-side rail  33  is, for example, a rail open at its upper surface. At the upper end of a side wall  33   a  of the panel-side rail  33 , plural locking pieces  35  are formed at regular intervals along the longitudinal direction (X direction) of the panel-side rail  33 . 
     The pad-side rail  34  is, for example, a rail open at its lower surface and its opposite end surfaces in the longitudinal direction. The pad-side rail  34  has an opening  34   c  formed at substantially the center in the longitudinal direction (X direction) over a region from the upper surface  34   a  to the side surface  34   b.  When the panel-side rail  33  is inserted into the pad-side rail  34 , the opening  34   c  exposes some of the locking units pieces  35  of the panel-side rail  33 . 
     The opening  34   c  receives an engagement piece  51  of a swinging member  41  that constitutes the stopper mechanism  22 . Once the engagement piece  51  of the swinging member  41  has been inserted into the opening  34   c,  engagement holes  52  formed in the engagement piece  51  engage with the locking pieces  35  exposed from the opening  34   c.    
     The aforementioned side surface  34   b  of the pad-side rail  34  is equipped with a rib  34   d  for oscillatably holding the swinging member  41  and a pin  34   e  that comes into contact with one end of a coil spring  36  attached to the rib  34   d . The coil spring  36  depresses the swinging member  41  in the R 1  direction of  FIG. 7 . 
     The stopper mechanism  22  is composed of the plural locking pieces  30  formed in the panel-side rail  27  and the plural locking pieces  35  formed in the panel-side rail  33  as well as the swinging members  40 ,  41  and a coupling member  42 . The swinging member  40  has the engagement piece  45  at one end in the longitudinal direction, which protrudes in the Y direction. The engagement piece  45  includes three engagement holes  46  arranged at regular intervals. The three engagement holes  46  are engaged with the locking pieces  30  that exist on the motion trajectories of the respective engagement holes  46  out of the plural locking pieces  30  formed in the floor-side rail  27 . The size of the three engagement holes  46  is set so as to receive the locking pieces  30  that exist on the motion trajectories of the respective engagement holes  46  when the swinging member  40  oscillates. Here, the number of engagement holes formed in the engagement piece  45  is not limited to three and one or more holes suffice for the purpose. 
     The swinging member  40  has an opening  47  at substantially the center in the longitudinal direction. In the opening  47 , inserted is a fastener (not shown) for attaching the swinging member  40  to the pad-side rail  28 . The fastener is fixed to the rib  28   d  disposed on the side surface  28   b  of the pad-side rail  28 . A pin  48  is provided in the vicinity of the opening  47 . The one end of the coil spring  31  attached to the rib  28   d  comes into contact with the pin  48  from below. 
     Likewise, the swinging member  41  has an engagement piece  51  at one end in the longitudinal direction, which protrudes in the −Y direction. The engagement piece  51  has three engagement holes  52  arranged at regular intervals. The three engagement holes  52  engage with the locking pieces  35  existing on the motion trajectories of the respective engagement holes  52  out of the locking pieces  35  formed in the floor-side rail  33 . The size of each engagement hole  52  is set so as to receive a corresponding locking piece  35  when the swinging member  41  oscillates. Here, the number of engagements hole  52  formed in the engagement piece  51  is not limited to three and one or more holes suffice for the purpose. 
     The swinging member  41  has an opening  53  at substantially the center in the longitudinal direction. A fastener (not shown) is inserted into the opening  53  so as to attach the swinging member  41  to the pad-side rail  34 . The fastener is fixed to the rib  34   d  disposed on the side surface  34   b  of the pad-side rail  34 . A pin  54  is provided in the vicinity of the opening  53 . The one end of the coil spring  36  attached to the rib  34   d  comes into contact with the pin  54  from below. 
     The coupling member  42  is a member for coupling, the swinging members  40  and  41  together. One end of the coupling member  42  in the longitudinal direction is fixed to the other end of the swinging member  40  opposite to the one end with the engagement piece  45 . In addition, the other end of the coupling member  42  in the longitudinal direction is fixed to the other end of the swinging member  41  opposite to the one end with the engagement piece  51 . 
     The operation button  23  is an operation member to be depressed by the foot (specifically, heel) when sliding the pad main body  20  toward or away from the pedal  14 . The operation button  23  is provided on the footboard  15   b  of the pad main body  20 . The operation button  23  is movable between a first position (see  FIG. 5B ) at which the button protrudes from the footboard  15   b  and a second position (see  FIG. 5C ) that the button reaches when depressed from the first position by a predetermined amount. 
     As shown in  FIG. 5A , the operation button  23  is composed of, for example, a rectangular button main body  55  and a pin-like depressing portion  56  disposed below the button main body  55 . At the upper end of the button main body  55 , a stopper piece  57  is formed throughout the outer periphery thereof. The operation button  23  is fit in a receiving hole  60  funned in the footboard  15   b  of the pad main body  20 . The receiving hole  60  is composed of a first hole  60   a  into which the button main body  55  is inserted, a second hole  60   b  into which the stopper piece  57  is inserted, a third hole  60   c  into which the depressing portion  56  is inserted, and a groove portion  60   d  into which an anti op cover  61  is inserted. Here, reference symbol  61   a  indicates an opening formed in the anti-drop cover  61 . The upper end of the button main body  55  is inserted thereinto. 
     As shown in  FIG. 5B , after the operation button  23  has been fit in the receiving hole  60  with the depressing portion  56  inserted into the coil spring  62 , the anti-drop cover  61  is inserted to the groove portion  60   d.  Once the operation button  23  has been fit in the receiving hole  60 , the lower end of the coil spring  62  comes into contact with a step portion  60   e  defined by the first hole  60   a  and the third hole  60   c,  and the upper end of the coil spring  62  comes into contact with a lower surface of the button main body  55 . Accordingly, the operation button  23  fit in the receiving hole  60  is biased by the coil spring  62  and secured in position with the upper surface of the stopper piece  57  in contact with the lower surface of the anti-drop cover  61 . The position of the operation button  23  in this state is a first position. When the operation button  23  is set to the first position, the upper surface (surface to be depressed)  55   a  of the button main body  55  protrudes from the footboard  15   b  of the pad main body  20  by a predetermined amount. Also, the tip end of the depressing portion  56  of the operation button  23  protrudes from the lower surface of the pad main body  20 . 
     As shown in  FIG. 5C , when being depressed, the operation button  23  moves downward (−Z direction) against the biasing force from the coil spring  62 . For example, if the operation button  23  is depressed down to the position at which the surface to be depressed  55   a  of the operation button  23  is flush with the upper surface of the anti-drop cover  61 , the lower surface of the stopper piece  57  comes into contact with a step portion  60   f  defined by the first hole  60   a  and the second hole  60   b.  The position of the operation button  23  in this state is the second position. In case the operation button  23  is depressed down to the second position, the protrusion amount of the depressing portion  56  from the lower surface of the pad main body  20  is larger than at the first position. 
     Referring to  FIGS. 6-9 , a description is given next of an example where the pad main body  20  of the sliding-type heel pad  15  of this embodiment is slid to adjust the height of the footboard.  FIGS. 7 and 9  show the swinging member  40 . In  FIGS. 7 and 9 , only the coupling member  42  and the engagement piece  45  of the swinging member  40  are indicated by solid line, and the other portions of the swinging member  40  are indicated by double-dashed line. 
     As shown in  FIGS. 6 and 7 , when the operation button  23  is not depressed, the operation button  23  is held in the first position. The coil spring  31  attached to the rib  28   d  biases the swinging member  40  in the R 1  direction of  FIG. 7 , and the coil spring  36  attached to the rib  34   d  biases the swinging member  41  in the R 1  direction of  FIG. 7 . Hence, the coupling member  42  connected with the swinging members  40 ,  41  is also biased to the R 1  direction of  FIG. 7 . The operation button  23  held in the first position, however, restricts the turning of these members in the R 1  direction. 
     When the operation button  23  is held in the first position, the three engagement holes  46  formed in the engagement piece  45  of the swinging member  40  engage with corresponding locking pieces  30  existing on the motion trajectories of the three engagement holes  46  of the swinging member  40  out of the locking pieces  30  of the panel-side rail  27 . At the same time, the three engagement holes  52  formed in the engagement piece  51  of the swinging member  41  engage with corresponding locking pieces  35  existing on the motion trajectories of the three engagement boles  52  of the swinging member  41  out of the locking pieces  35  of the panel-side rail  33 . Accordingly, when the operation button  23  is held in the first position, the sliding mechanism  22  functions, inhibiting the sliding movement of the pad main body  20 . 
     When the operation button  23  is depressed by the driver&#39;s heel, the operation button  23  is moved downward (−Z direction) against the biasing force of the coil spring  62 . Subsequently, when the stopper piece  57  comes into contact with the step portion  601  of the receiving hole  60 , the downward movement of the operation button  23  is restricted. As a result, the operation button  23  is held in the second position (see  FIG. 9 ). 
     If the operation button  23  moves downward from the first position after being depressed by the heel, the depressing; portion  56  of the operation button  23  protruding from the lower surface of the pad main body  20  depresses the coupling member  42 . When the depressing portion  56  of the operation button  23  depresses the coupling member  42 , the coupling member  42  turns around the rib  28   d  where the swinging member  40  is held and the rib  34   d  where the swinging member  41  is held in the R 2  direction of  FIG. 7  together with the swinging members  40 ,  41 . 
     When the swinging member  40  turns in the R 2  direction of  FIG. 7 , the engagement piece  45  of the swinging member  40  separates from the locking piece  30  of the panel-side rail  27 , whereby the respective engagement holes  46  of the engagement piece  45  disengage from the respective locking pieces  30  of the panel-side rail  27  that have been engaged with the engagement holes  46  (see  FIGS. 8 and 9 ). 
     As the swinging member  40  turns in the R 2  direction, the swinging member  41  also turns in the R 2  direction. The turning of the swinging member  41  in the R 2  direction makes the engagement piece  51  of the swinging member  41  apart from the locking piece  35  of the panel-side rail  33 . The turning of the swinging member  41  in the R 2  direction disengages the respective engagement holes  52  of the engagement piece  51  from the locking pieces  35  of the panel-side rail  33  that have been engaged with the engagement holes  52 . Here, the engagement pieces  45 ,  51  of the swinging members  40 ,  41  turned in the R 2  direction enter into a recess  20   c  formed at the bottom of the pad main body  20 . 
     Accordingly, if the operation button  23  is depressed, the function of the sliding mechanism  22  is disabled, whereby the pad main body  20  can slidably move toward or away from the pedal  14 . 
     A driver slidably moves the pad main body  20  toward or away from the pedal  14  while continuously depressing the operation button  23  using the heel. When the pad main body  20  is slidably moved to a desired position, the driver releases the heel from the operation button  23 . 
     As shown in  FIG. 9 , when the operation button  23  is released from being depressed by the heel, the operation button  23  at the second position moves upward (Z direction) by means of restoring force of the coil spring  60 . Then, the operation button  23  moves to a position where the stopper piece  57  of the button main body  55  comes into contact with the anti-drop cover  61  (see  FIG. 7 ). 
     As a result of upward movement of the operation button  23 , the depressing portion  56  no longer depresses the coupling member  42 . As described above, the swinging member  40  is biased by the coil spring  31 . Also, the swinging member  41  is biased by the coil spring  36 . Accordingly, when the operation button  23  is raised, the swinging members  40 ,  41  turn in the R 1  direction of  FIG. 9  by means of the restoring force of the coil springs  31 ,  36 . Together with the turning of these two swinging members  40 ,  41  in the R 1  direction, the coupling member  42  also turns in the R 1  direction of  FIG. 9 . Therefore, upon the upward movement of the operation button  23 , the coupling member  42  is moved while in contact with the depressing portion  56  of the operation button  23 . 
     When the stopper piece  57  of the operation button  23  comes into contact with the anti-drop cover  61 , the operation button  23  stops moving upward and is held in the first position. If the operation button  23  is held in the first position, the turning of the coupling member  42  in the R 1  direction is stopped as well. 
     When the operation button  23  is being raised toward the first position, the swinging members  40 ,  41  turn in the R 1  direction of  FIG. 9 . The turning of the swinging member  40  in the R 1  direction of  FIG. 9  makes the engagement piece  45  move toward the locking piece  30  exposed from the opening  28   c  of the pad-side rail  28 . Then, if any locking pieces  30  exist on the motion trajectories of corresponding ones of the engagement holes  46  formed in the turned engagement piece  45 , these locking pieces  30  are inserted into the engagement holes  46  of the engagement piece  45 . Accordingly, the respective engagement holes  46  engage with the locking pieces  30  corresponding to the engagement holes  46  (see  FIG. 7 ). 
     Concurrently with the turning of the swinging member  40  in the R 1  direction of  FIG. 9 , the swinging member  41  also turns in the R 1  direction. Owing to the turning of the swinging member  41  in the R 1  direction of  FIG. 9 , the engagement piece  51  moves toward the locking piece  35  exposed from the opening  34   c  of the pad-side rail  34 . Then, if any locking pieces  35  exist on the motion trajectories of corresponding ones of the engagement holes  52  formed in the turned engagement piece  51 , these locking pieces  35  are inserted into the engagement holes  52  of the engagement piece  51 . Accordingly, the respective engagement holes  52  engage with the locking pieces  35  corresponding to the engagement holes  52 . 
     Depending on the position of the slidably moved pad main body  20 , the position of the locking piece  30  formed in the panel-side rail  27  may be out of the motion trajectories of the engagement holes  46  of the engagement piece  45  of the swinging member  40 . In such a case, the locking piece  30  formed in the panel-side rail  27  is not inserted into the engagement hole  46  of the engagement piece  45  of the swinging member  40 . As a result, the engagement piece  45  of the swinging member  40  comes into contact with the locking piece  30  formed in the panel-side rail  27 . The same applies to the swinging member  41 . Thus, the function of the stopper mechanism  22  is disabled. In this case, the pad main body  20  is slidably moved toward or away from the pedal  14 . The sliding movement releases the engagement piece  45  of the swinging member  40  from being in contact with the locking piece  30  formed in the panel-side rail  27  and then, the locking piece  30  funned in the panel-side rail  27  is inserted into the engagement hole  46  of the engagement piece  45  of the swinging member  40 . Hence, the stopper mechanism  22  functions. 
     As described above, as a result of raising the operation button  23  from the second position to the first position, the sliding mechanism  22  can function again to restrict sliding movement of the pad main body  20  toward or away from the pedal  14 . 
     Just by slidably moving the pad main body  20  with the operation button  23  being depressed by the driver&#39;s foot, the position of the pad main body  20  as well as the height of the footboard of the sliding-type heel pad  15  can be easily adjusted at the same time, Also, if a driver wants to hold the pad main body  20  in a desired position, the driver has only to release the foot from the operation button  23 . Hence, the driver can adjust the height of the footboard according to body form. 
     The configuration of the sliding mechanism discussed in the above embodiment is merely given as an example, and any other sliding mechanism is possibly used. Examples of such sliding mechanisms include the one configured by combining a T- or I-shaped rail in cross-section with a rail capable of fitting in the rail from the outside thereof, and the one configured by combining a wheel attached to the pad main body with a panel-side rail that is open at its upper surface to receive the wheel. 
     The same applies to the stopper mechanism. For example, the stopper mechanism may be composed of a latch provided along the longitudinal direction of a rail, and a latch hook capable of engaging with the latch. 
     In this embodiment, two rail pairs are independently provided with the swinging member, but only one rail pair may have the swinging member. 
     In this embodiment, in order to disable the function of the stopper mechanism, the operation button  23  is depressed by way of an example. However, an operation lever (foot lever) that is operable by the driver&#39;s foot (specifically, heel) can replace the operation button  23 . 
     As shown in  FIG. 10 , a foot lever  71  disposed on the sliding-type heel pad  66  includes a footboard  71   a,  and supporting pieces  71   b,    71   c  that are provided at both ends of the footboard  71   a,  extending in the X direction. The supporting piece  71   b  has plural groove portions  72  at the lower end of its tip end, which are arranged at predetermined intervals. Likewise, the supporting piece  71   c  has plural groove portions  73  at the lower end of its tip end, which are arranged at predetermined intervals. In the illustrated example of  FIG. 10 , the supporting pieces  71   b ,  71   c  have five groove portions  72 ,  73 , respectively. In this embodiment as well, the two-step pad main body  67  with two footboards  67   a,    67   b  at different heights is used. 
     The supporting piece  71   b  is attached in an axially tamable manner to a side surface  67   c  of the pad main body  67 . Reference numeral  74  indicates an opening through which a fastener (not shown) is inserted when the supporting piece  71   b  is attached in an axially turnable manner to the side surface  67   c  of the pad main body  67 . The supporting piece  71   b  is equipped with a pin  75  between the opening  74  and a portion continuous to the footboard  71   a  in the longitudinal direction of the supporting piece  71   b.  The side surface  67   c  of the pad main body  67  has a pin  76 , and the coil spring  77  is connected to the pin  76  at one end and to the pin  75  at the other end. 
     Likewise, the supporting piece  71   c  is attached in an axially turnable manner to a side surface  67   d  of the pad main body  67 . Reference numeral  78  indicates an opening through which a fastener (not shown) is inserted when the supporting piece  71   c  is attached in an axially turnable manner to the side surface  67   d  of the pad main body  67 . The supporting piece  71   c  is equipped with a pin  79  between the opening  78  and a portion continuous to the footboard  71   a  in the longitudinal direction of the supporting piece  71   c.  The side surface  67   d  of the pad main body  67  has a pin  80 , and the coil spring  81  is attached to the pin  80  at one end and to the pin  79  at the other end. 
     If the foot lever  71  is used, the sliding mechanism  85  is composed of, as in the above embodiment, two pairs of rails, i.e., rail pairs  86 ,  87 . Here, the rail pair  86  is configured such that a pad-side rail  89  is inserted into a panel-side rail  88 , and the rail pair  87  is configured such that a pad-side rail  91  is inserted into a panel-side rail  90 . The side surface of the panel-side rail  88  has a pin  93  that is engageable with any one of the plural groove portions  72  formed in the supporting piece  71   b . Furthermore, the side surface of the panel-side rail  90  has a pin  94  that is engageable with any one of the plural groove portions  72  formed in the supporting piece  71   c.    
     Thus, if the foot lever  71  is used, the stopper mechanism is achieved by combining the supporting piece  71   b  and the pin  93  on the side surface of the panel-side rail  88 , and combining the supporting piece  71   c  and the pin  94  on the side surface of the panel-side rail  90 . 
     As shown in  FIG. 11 , in the sliding-type heel pad  70  with the foot lever  71 , if the foot lever  71  is not operated, the supporting piece  71   b  is biased toward the R 3  direction of  FIG. 11  by the coil spring  77 . It means that the pin  93  on the side surface of the panel-side rail  88  engages with any one of the plural groove portions  72  of the supporting piece  71   b . Likewise, the supporting piece  71   c  is biased in the R 3  direction by the coil spring  81 . It means that the pin  94  on the side surface of the panel-side rail  90  engages with any one of the plural groove portions  73  of the supporting piece  71   c.    
     Once a driver puts the heel on the footboard  71   a  of the foot lever  71  and pushes down the footboard  71   a,  the foot lever  71  is turned in the R 4  direction. Upon the turning of the foot lever  71  in the R 4  direction, the footboard  71   a  as well as the supporting pieces  71   b ,  71   c  are turned against the biasing force from the coil springs  77 ,  81  toward the R 4  direction of  FIG. 11 . Accordingly, as shown in  FIG. 12 , the plural groove portions  72  formed in the supporting piece  71   b  are retracted from the pin  93  on the side surface of the panel-side rail  88  to thereby disengage a corresponding one of the plural groove portions  72  formed in the supporting piece  71   b  from the pin  93  disposed on the panel-side rail  88 . Likewise, a corresponding one of the plural groove portions  73  formed in the supporting piece  71   c  is disengaged from the pin  94  disposed on the panel-side rail  90 . Thus, the function of the stopper mechanism is disabled, whereby the pad main body  67  can slidably move. 
     After slidably moving the pad main body  67  to a desired position while pushing down the foot lever  71 , a driver releases the foot from the footboard  71   a  of the foot lever  71 . As described above, the supporting pieces  71   b  and  71   c  are biased in the R 3  direction by the coil springs  77  and  81 , respectively. Once the foot lever  71  is released from the foot, the supporting piece  71   b  is turned in the R 3  direction by means of the biasing force from the coil spring  77 . Hence, the foot lever  71  is turned in the R 3  direction of  FIG. 12 . Here, if the pin  93  on the side surface of the panel-side rail  88  exists on the motion trajectory of any one of the plural groove portions  72  formed in the supporting piece  71   b,  the pin  93  can engage with the groove portion  72  that takes the motion trajectory on which the pin  93  exists, when the foot lever  71  is turned in the R 3  direction. The same applies to the supporting piece  71   c.  The above engagement inhibits the foot lever  71  from turning in the R 3  direction. As a result, the stopper mechanism functions to restrict the sliding movement of the pad main body  67 . 
     Accordingly, in this embodiment as well, the position of the pad main body  67  and the height of the footboard can be easily adjusted only by slidably moving the pad main body  67  with the foot lever  71  being pushed down by the driver&#39;s foot as in the above embodiment. Also, if a driver wants to hold the pad main body  67  in a desired position, the driver has only to release the foot from the footboard of the foot lever  71 . The driver can easily adjust the height of the footboard according to body form in this way.