Patent Publication Number: US-6983671-B2

Title: Cantilever-style pedal assembly

Description:
FIELD OF THE INVENTION 
   This invention relates to pedals, and more particularly to an improved cantilever style pedal assembly for a vehicle. 
   BACKGROUND OF THE INVENTION 
   Vehicles, such as motor vehicles, typically contain foot-actuated devices or pedals for controlling various functions of the vehicle. These functions are known to include: acceleration, controlled by an accelerator pedal; braking, controlled by a brake pedal; and shifting, controlled by a clutch pedal. In addition, the vehicle may include a non-functional pedal that serves as a footrest for the driver. These pedals are positioned in the vehicle so that they are accessible by the driver, and may be fixed or adjustable. 
   The pedal assembly includes a pedal arm pivotally mounted to a support bracket, and the support bracket is fixedly mounted to the vehicle. A pedal pad is mounted to a lower end of the pedal arm for depression by the driver&#39;s foot. The upper end of the pedal arm is attached to an actuating mechanism for controlling a vehicle function such as braking, accelerating or clutching. Vehicle packaging considerations may influence the shape of the pedal arm. A cantilever style pedal arm has a first pedal arm with a pedal pad attached to a lower end of the first pedal arm and an upper end of the first pedal arm is attached to a hub or cross-member. It also has a second pedal arm attached to the hub at one end and the actuating mechanism at the other end. 
   The brake and accelerator systems are subject to various regulatory requirements. For a brake system, the regulatory requirements may stipulate braking distance, or a redundancy in the case of a component failure. With respect to a cantilever style brake pedal system, each pedal arm is fixedly mounted to a cross-member, such as by welding. While the weld connection works well, it could fracture when subject to an excessive force, such as in an emergency situation. As a result, each pedal arm would not rotate as a single unit. Thus, there is a need in the art for a cantilever style pedal assembly having an improved structural configuration. 
   SUMMARY OF THE INVENTION 
   Accordingly, the present invention is an improved pedal assembly. The pedal assembly includes a support bracket having a mounting face and two spaced apart side walls extending from opposing edges of said mounting face. The pedal assembly also includes a hub assembly rotatably connected between the side walls of the support bracket, wherein the hub assembly includes an outer hub member having a rectangular cross-sectional shape and a rectangular channel extending therethrough, an inner hub member having a solid circular shape, and a bushing disposed in each end of the outer hub member for supporting the inner hub member within the outer hub member. The pedal assembly further includes a first pedal arm, wherein an upper end of the first pedal arm is fixedly mounted to the hub assembly and a pedal pad is mounted to a lower end of the first pedal arm and a second pedal arm, such that a lower end of the second pedal arm is fixedly mounted to the hub assembly, such that the first pedal arm, hub assembly and second pedal arm rotate together as an integral member. 
   One advantage of the present invention is that a brake pedal assembly is provided that improves brake effectiveness. Another advantage of the present invention is that a pedal assembly is provided with improved structural reliability. A further advantage of the present invention is that the master cylinder and brake booster size are optimized with respect to the pedal ratio as a result of the improved structure. 
   Other features and advantages of the present invention will be readily understood as the same becomes better understood after reading the subsequent description when considered in connection with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a elevational rear view of a pedal assembly, according to the present invention. 
       FIG. 2  is a perspective front view of the pedal assembly of  FIG. 1 , according to the present invention. 
       FIG. 3  is a perspective view of the pedal arm assembly of  FIG. 1 , according to the present invention. 
       FIG. 4  is a perspective view of a silencer member for use with the pedal assembly of  FIG. 1 , according to the present invention. 
       FIG. 5  is a perspective view of hub bushing for use with the pedal assembly of  FIG. 1 , according to the present invention. 
       FIG. 6  is a sectional view taken through line  6 — 6  of  FIG. 1  of the hub assembly, according to the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Vehicles, including a motor vehicle (not shown) utilize foot-actuated devices, referred to as pedals, to control a particular function of the vehicle, such as accelerating, braking and shifting. These pedals are referred to in the art as an accelerator pedal, brake pedal, clutch pedal, and parking brake pedal respectively. In addition, the vehicle may include a non-functional pedal that provides a footrest for the non-active foot, such as the left foot in a left-hand drive vehicle. The pedals are aligned in a predetermined dimensional relationship relative to each other, and fixed portions of the vehicle, including the vehicle dash panel, floor, seat and instrument panel. The pedal pad portion of the pedal assembly travels in a predetermined path, typically an arc. In an adjustable pedal assembly, the height of the pedal pad (to be described) with respect to the floor is modified by moving the pedal pad either closer to or away from the driver. 
   Referring to  FIGS. 1–6 , a pedal assembly  10  for translating a signal between a vehicle operator or driver (not shown) and an actuating mechanism (not shown) is illustrated. In this example, the pedal assembly is a brake pedal assembly  10 . The brake pedal assembly  10  is fixedly mounted to a dash panel portion of the vehicle (not shown) in a conventional position beneath the instrument panel. The brake pedal assembly  10  includes a support bracket  12  for attaching the brake pedal assembly  10  to the dash panel. The support bracket  12  includes a generally planar mounting face  14 . In this example the mounting face  14  has an “L” shape. The mounting face includes at least one aperture  16  for attaching the support bracket  12  to the vehicle using an attaching means, such as by bolting or the like. It should be appreciated that in this example the mounting face  14  includes an outwardly projecting boss  18  surrounding the aperture  16 , and a reinforcing insert  20  is disposed inside the aperture  16 . 
   The support bracket  12  also includes two spaced apart side walls  22  extending radially from opposing edges of the mounting face  14 . Each side wall  22  provides a mounting surface for pivotally supporting the pedal arm assembly, in a manner to be described. 
   The brake pedal assembly  10  also includes a cantilever style pedal arm assembly  24  having a first pedal arm  26 , a second pedal arm  28 , and a hub assembly  30  interconnecting the first and second pedal arms  26 , 28 . The first pedal arm  26  has a pedal pad  32  mounted at a lower end. The pedal pad  32  provides a pedal actuation point for transmitting the force of the driver&#39;s foot contacting the pedal pad  32  to the braking mechanism to control the movement of the vehicle. Preferably, the pedal pad  32  is made from an isomeric material, such as rubber. 
   An upper end of the first pedal arm  26  is fixedly attached a hub assembly  30 . In this example, the first pedal arm  26  is attached to the hub assembly  30  by welding or the like. The hub assembly  30  functionally supports the first pedal arm  26  and transmits the pivotal movement of the first pedal arm  26  to the second pedal arm  28  and the brake mechanism in a manner to be described. The hub assembly  30  extends longitudinally between the sidewalls  22  of the support bracket  12 , and is pivotally supported by the sidewalls  22 . 
   The hub assembly  30  includes an outer member  34  that is tubular and has a rectangular cross-sectional shape. The rectangular cross-sectional shape is advantageous, since it provides improved structural strength and durability. In addition, if the weld connection between either of the pedal arms  26 ,  28  and outer hub member  34  should break, the orientation of the first pedal arm  26  with respect to the second pedal arm  28  remains fixed, and the first pedal arm  26 , second pedal arm  28  and a hub assembly  30  continue to operate as an integral member. 
   The hub assembly  30  also includes an inner member  36 , such as a pivot shaft, supported within the interior portion of the outer member  34  using a hub bushing  38 . In this example, the inner member  36  is a longitudinally extending pivot shaft or rod. The inner member  36  is pivotally attached to the sidewall  22  of the support bracket  12 , such as by a pivot pin or a shoulder connection or the like. 
   The hub bushing  38  is disposed within an open end of the outer member  34 , and advantageously transfers the motion of the outer member  34  to the inner member  36  or pivot shaft. The hub bushing  38  includes a main portion  40  having a rectangular exterior cross-sectional shape. The interior of the main portion  40  of the hub bushing  38  includes a channel  42  that is circular in cross-sectional shape, for receiving the inner member pivot pin  36 . It should be appreciated that a plurality of longitudinally extending channels may be formed in the interior wall of the main portion  40  to facilitate the rotational movement of the inner member  36 . The exterior shape of hub bushing  38  corresponds dimensionally to the interior dimensional shape of the outer member  34 , and is correspondingly smaller, so that the hub bushing  38  fits within the end of the outer member  34 . One end of the hub bushing  38  includes a flange  44  extending radially outward from an end of the main portion  40  of the hub bushing  38 . When the hub bushing  38  is inserted in the end of the outer member  34 , the flange  44  is positioned between the outer member  34  and sidewall  22 , and provides for additional structural support to the hub assembly  30 . 
   The pedal arm assembly  24  further includes a second pedal arm  28  for transferring the rotational motion of the hub assembly  30  and first pedal arm  26  to the brake mechanism. One end of the second pedal arm  28  is fixedly attached to the outer hub member  34 , preferably near an opposite end from the first pedal arm  26 . The other end of the second pedal arm  28  is pivotally attached to an actuating mechanism such as the brake rod booster link (not shown) that distributes the load transferred from the first pedal arm  26  to the brake mechanism of this example. The second pedal arm  28  is a generally planar member. In this example, the second pedal arm  28  includes a radially extending attaching means  48  for pivotally connecting the second pedal arm  28  to the brake booster rod. In this example the attaching means  48  is a pin, although other types of attaching means are contemplated, such as a ball joint. It should be appreciated that one end of the brake booster rod is operatively attached to the attaching means  48  and another end is operatively attached to the brake booster, as is known in the art, and transmits the force of the operator applying the brakes from the brake pedal assembly  10  to the braking system. The length of the first and second pedal arms  26 ,  28  and relative position on the outer hub member  34  are configured to obtain the desired geometry. 
   Preferably, the brake pedal assembly  10  includes a spring member  60  operatively disposed on the hub assembly  30  for controlling the movement of the brake pedal assembly  10  between a resting and braking position, as is known in the art. In this example, the spring member  60  is a torsion spring. 
   The brake assembly  10  also includes a silencer member  50 , or bushing, placed on the outer hub member  34  in a predetermined location. Advantageously, the silencer member  50  reduces or eliminates any noise between the spring  60  and the outer hub member  34 . The silencer member  50  includes a main portion  52  having a rectangular cross-sectional shape and a hollow center portion  54 . One end of the main portion  52  includes a radially extending flange  56  that is circular in shape. It should be appreciated that the radially extending flange  56  may include a cut-away portion  58  to accommodate packaging the second pedal arm  28  and spring member  60  on the hub assembly  30 . 
   It should be appreciated that the brake pedal assembly  10  may include other components, such as switches  62 , switch mounting brackets  64  or a stop (not shown), which are conventional and known in the art for the brake pedal assembly  10 . 
   In operation, as the driver depresses the pedal pad  32 , the rotational movement of the first pedal arm  26  is transferred to the hub assembly  30 , which transfers the motion to the second pedal arm  28 . The motion is transferred from the second pedal arm  28  to the brake booster rod, and the braking mechanism of this example, to control the movement of the vehicle, by applying a force to slow down the rotational movement of the vehicle. It should be appreciated that the first pedal arm  26 , hub assembly  30  and second pedal arm  28  rotate as a single, integral member. Advantageously, the structural strength of the hub assembly  30  is improved by combining the rectangular outer member  34  and circular inner member  36 , versus a single pivot rod. In addition, the first pedal arm  26 , hub assembly  30  and second pedal arm  28  will rotate as an integral member, regardless of the integrity of the weld connection. 
   The present invention has been described in an illustrative manner. 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. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.