Abstract:
A pedal assembly includes a one-piece accelerator pedal without moving linkages that is mounted to a pin for rotational movement relative to a mounting stay. The throttle cable is operatively connected to the accelerator pedal for movement thereby as the pedal rotates, at least one of the pedal and mounting stay configured to provide a first ratio of pedal stroke movement relative to cable stroke movement at initial depression of the accelerator pedal, and a different, second ratio of pedal stroke movement relative to cable stroke movement upon further depression of the accelerator pedal.

Description:
BACKGROUND 
     The present disclosure relates to a throttle or accelerator pedal, and an associated method of developing more holding power resulting from simultaneously depressing a brake pedal and a throttle pedal by modifying a ratio of the throttle pedal. It finds particular application in conjunction with a variable ratio throttle pedal. However, it is to be appreciated that the present exemplary embodiment is also amenable to other like applications that encounter similar problems or require similar solutions. 
     Currently, an accelerator pedal is pivotally moved relative to a mount or mounting stay. A throttle cable is, in turn, secured to the accelerator pedal so that pulling of the throttle cable matches the movement of the accelerator pedal. That is, the cable stroke or cable pull ratio matches the ratio of pedal stroke movement throughout the actuation/deactuation of the pedal. There is only a small incidental variation in the ratio so that the cable pull ratio is dictated by the accelerator pedal ratio. Typically, a line of action for the cable is aligned with a top of the accelerator pedal. The intent is to maintain a linear accelerator pedal input and as a result the cable end follows an arc controlled by a pivot location of the pedal. This ensures minimal change to the pedal to cable stroke ratio. 
     It is desirable to assure that brake force builds faster than engine torque when both brake and accelerator pedals are simultaneously depressed. Variable ratio throttle systems are per se known. The change in rate, however, is usually practical due to the environment the pedals are subjected to. For example, water, ice, mud, etc. could potentially lodge in the cam and as a result the throttle cable would become dislodged from its desired line of action. Thus, a simplified structure that assures that opening of an engine throttle is slower than application of the brake is required. Also, with a variable ratio pedal, is desirable that the operator/driver not detect the slower action of the accelerator at small pedal angles and assure that action of the accelerator at normal driving modes be in the range of traditional or more normal pedal to cable pull ratios. 
     This disclosure remedies these problems in a simple, reliable, effective, and inexpensive manner. 
     BRIEF DESCRIPTION 
     There is provided a pedal assembly, namely an accelerator pedal assembly, in which a throttle cable attaches to an accelerator pedal at an angle so that the throttle cable provides a variable angle as the pedal is actuated or depressed, and wherein the pedal is a one-piece member without moving linkages to provide the variable angle. 
     More particularly, the pedal assembly includes a mounting stay and a pin fixedly secured to the mounting stay. The one-piece accelerator pedal without moving linkages is mounted to the pin for rotational movement about the pin relative to the mounting stay. The throttle cable is operatively connected to the accelerator pedal for movement thereby as the pedal rotates, at least one of the pedal and mounting stay configured to provide a first ratio of pedal stroke movement relative to cable stroke movement at initial depression of the accelerator pedal, and a different, second ratio of pedal stroke movement relative to cable stroke movement upon further depression of the accelerator pedal. 
     The throttle cable is secured to the accelerator pedal for initial movement at an angle relative to a tangent of the pedal travel path. 
     The angle ranges from approximately 45° to approximately −7° relative to the tangent of the pedal travel path. 
     The throttle cable is substantially tangent to the pedal travel path at the end of the cable stroke. 
     The mounting stay includes a mounting region that receives the throttle cable and orients the throttle cable substantially perpendicular to an initial portion of the angled pedal travel path. 
     The accelerator pedal includes a mounting region that receives a first end of the throttle cable. 
     The pedal assembly further includes a brake pedal assembly that is configured to provide a brake force that is greater than an engine torque. 
     The brake force is greater than the engine torque during the first ratio of pedal stroke movement relative to cable stroke movement at initial depression of the accelerator pedal. 
     A method of varying a ratio of pedal stroke movement relative to cable stroke movement during actuation of an accelerator pedal includes mounting an accelerator pedal to a pin for rotational movement about the pin. The method further includes connecting a throttle cable to the accelerator pedal for movement in different first and second ratios of pedal stroke to cable stroke movement during actuation of the accelerator pedal. 
     The method includes securing the throttle cable to the accelerator pedal for initial movement at an angle relative to a tangent of the pedal travel path. 
     The method includes providing a first ratio of pedal stroke movement relative to cable stroke movement at initial depression of the accelerator pedal, and a different, second ratio of pedal stroke movement relative to cable stroke movement upon further depression of the accelerator pedal. 
     The method includes providing a greater ratio of pedal stroke movement relative to cable stroke movement during initial depression of the accelerator pedal than later in the pedal stroke movement. 
     The method includes providing greater braking force than engine torque during the first ratio of pedal stroke movement relative to cable stroke movement at initial depression of the accelerator pedal. 
     The method includes forming the pedal as a one-piece component without moving linkages. 
     One benefit of the present disclosure is assuring that the brake force builds faster than the engine torque when both brake and accelerator pedals are simultaneously depressed. 
     Yet another advantage is the ability to address this issue without substantially altering the remaining components of the current system. 
     Still another benefit is the simple, less complex manner of achieving a variable ratio throttle/accelerator pedal assembly. 
     Still other benefits and advantages will become apparent those skilled in the art after reading and understanding the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic elevational view of an accelerator pedal assembly known in the art. 
         FIG. 2  is an enlarged detail view of a portion of  FIG. 1 . 
         FIG. 3  is a representation of a line of action of a throttle cable associated with the arrangement of  FIGS. 1 and 2 . 
         FIG. 4  is a graphical representation of pedal stroke versus cable stroke/pull. 
         FIG. 5  is a schematic elevational view of an accelerator pedal assembly of the present disclosure. 
         FIG. 6  is a representation of a line of action of the throttle cable associated with the accelerator pedal assembly of  FIG. 5 . 
         FIG. 7  is an enlarged detail view of a portion of  FIG. 5 . 
         FIG. 8  is a schematic elevational view of a mounting stay and accelerator pedal. 
         FIG. 9  is an elevational view taken generally from along the right-hand side of  FIG. 8 . 
         FIG. 10  is an enlarged cross-sectional view taken generally along the lines  10 - 10  of  FIG. 8 . 
         FIG. 11  is a schematic of a brake pedal assembly including a brake pedal. 
     
    
    
     DETAILED DESCRIPTION 
     The description and drawings herein are merely illustrative, and various modifications and changes can be made in the structures disclosed without departing from what is defined in the appended claims. All references to direction and position, unless otherwise indicated, refer to the orientation of the structures and components illustrated in the drawings and should not be construed as limiting the claims appended hereto. Like numbers refer to like parts throughout the several views. 
     With reference to  FIG. 1 , there is shown a pedal assembly  100  such as used in an associated vehicle (not shown). In this particular instance, the pedal assembly  100  is an accelerator pedal assembly which includes an accelerator pedal  110  having a first arm or portion  112  through which a force is applied to the pedal, e.g. through application of a force via the foot of the vehicle user, and a second arm or portion  114  that connects with an accelerator or throttle cable  120 , particularly a first end thereof. The pedal  110  is mounted for rotation on pin  124  that is secured to a mounting surface or mounting stay  130 . The mounting stay  130  is commonly secured to a firewall or panel (not shown) in a manner generally known in the art so that it is common for the mounting stay to be secured to a substantially vertical wall of the vehicle. The pin  124  is thus disposed in spaced relation relative to this vehicle wall and allows pivotal movement of the pedal  110 . 
     Applying a force through the first arm  112  rotates the pedal  110  around the pin  124  (in a clockwise direction as shown) and likewise results in the same rotational movement of the second arm  114  (again, in the clockwise direction as shown). As a result of the rotational movement, the first end  122  of the throttle cable  120  is pulled as the accelerator pedal  110  rotates about the pin  124 . As shown in  FIGS. 1 and 2 , the full extent of rotation of the pedal  110  is illustrated by the two positions of the pedal. 
     The first end  122  of the throttle cable  120  travels along a substantially linear path  140  as the pedal is actuated ( FIG. 3 ). This travel is also represented in  FIG. 1  by reference numeral  142  as a stroke length or pull distance of the throttle cable  120 . The throttle cable end  122  follows arc  144  ( FIG. 3 ) controlled by the pin  124  or pedal pivot location. This has a minimal change to the pedal to cable stroke ratio. The line of action for the throttle cable  120  is aligned with the top of the accelerator pedal  110 , i.e., with the top of the second portion  114  of the accelerator pedal  110 . Although there may be a small variation in the ratio, the design intent with the current technology is to maintain a linear accelerator pedal input. Thus, the cable pull ratio traditionally matches the top of the accelerator pedal  110 , and there is only a small incidental variation in the ratio, so the cable pull ratio is driven by the pedal ratio. This is represented by a linear plot  146  in  FIG. 4 . 
     Where the accelerator pedal  110 ,  1120  and the brake pedal  100  are depressed at the same time, i.e. simultaneously, it is desirable that the vehicle not move. Therefore, it is desirable that the engine throttle opening is slower than the brake application. It becomes necessary to design the brake force to increase faster than the engine torque when both brake and accelerator pedals are depressed at the same time. This can be achieved with a variable ratio accelerator pedal, one output of which is illustrated by plot  150  in the graphical representation of  FIG. 4 . As mentioned in the Background, it is preferable to limit the complexity and number of changes to incorporate a variable ratio accelerator pedal. To that end, a new pedal assembly  200 ,  1100  is shown in  FIGS. 5-11  in order to achieve the variable ratio, preferably a first ratio  152  where there is an increased or greater pedal stroke relative to cable stroke through an initial portion of accelerator pedal depression, and then a second ratio  154  shown in  FIG. 4  as having the same ratio as that of the prior art arrangement of  FIGS. 1-3 . Of course the particularly selected ratio may vary without departing from the scope and intent of the present disclosure, although these are preferred ratios. 
     Reference numerals in the “100 series” (such as pedal assembly  100  in  FIGS. 1-3 ) now identify like components by reference numerals in the “200 series” (such as pedal assembly  200  in  FIGS. 5-11 ), and new components are also referenced by new numerals in the 200 series. Here, pedal assembly  200  is an accelerator pedal assembly which includes an accelerator pedal  210  having a first arm or portion  212  (through which a force is applied to the pedal) and a second arm or portion  214  that connects with an accelerator/throttle cable  220 , particularly a first end  222  thereof. The one-piece pedal  210  is mounted for rotation on pin  224  that is secured to a mounting surface or mounting stay  230 . The mounting stay  230  is secured to a firewall or panel (not shown) and the pin  224  allows pivotal movement of the pedal  210 . Rotation of the first arm  212  rotates the pedal  210  around the pin  224  (in a clockwise direction as shown) and likewise results in the same rotational movement of the second arm  214  (again, in the clockwise direction as shown). 
     As a result of the rotational movement, the first end  222  of the throttle cable  220  is pulled as the accelerator pedal  210  rotates about the pin  224 . The first end  222  of the throttle cable  220  travels along a path  240  ( FIG. 6 ) when the accelerator pedal  210  is actuated and this path is initially oriented at an angle “α” relative to the arc stroke or movement  242  of the accelerator pedal. By way of example, angle α may range from approximately 45° (for instance as shown in  FIG. 6 ) to approximately −7°. At the end of the stroke, the throttle cable  220  is virtually tangent (see reference numeral  260  in  FIG. 6 ) to the arc stroke  242  of the accelerator pedal  210 . Thus, the ratio of the pedal stroke to the cable stroke varies as illustrated in  FIG. 4 , from an initial ratio  152  to a second ratio  154 . Consequently, the cable pull ratio  152  transitions to a second ratio  154  resulting from the purposeful, initial positioning of the throttle cable  220  at an angle α to the arc path of the pedal  210  that then transitions to become tangent with the arc path of the accelerator pedal. 
     In this manner, where the accelerator pedal  210 ,  1120  and the brake pedal  1110  are depressed at the same time, i.e. simultaneously, the engine throttle opening is initially and desirably slower than the brake application. The new pedal assembly  200  effectively achieves the desired variable ratio by angling a surface  270  of the mounting stay that is oriented perpendicular to the initial path  240  defined by angle a. If the angle a is changed, then likewise the angle of surface  270  is altered to provide proper orientation of the throttle cable end  222  with accelerator pedal  210 . 
     Preferably the pedal  210  is a one-piece member without moving linkages. This eliminates undesired complexity, yet purposeful angling of the throttle cable  220  at the attachment point  222  with the accelerator pedal  210  still provides the desired variable ratio. This is also accomplished in a manner that does not require undue alteration of surrounding components in an existing vehicle design. 
     This written description uses examples to describe the disclosure, including the best mode, and also to enable any person skilled in the art to make and use the disclosure. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. Moreover, this disclosure is intended to seek protection for a combination of components and/or steps and a combination of claims as originally presented for examination, as well as seek potential protection for other combinations of components and/or steps and combinations of claims during prosecution.