Accelerator pedal

Information

  • Patent Grant
  • 6553863
  • Patent Number
    6,553,863
  • Date Filed
    Wednesday, April 12, 2000
    24 years ago
  • Date Issued
    Tuesday, April 29, 2003
    21 years ago
Abstract
An accelerator pedal assembly has a mounting bracket and a pedal arm mounted to the bracket for pivotal movement between an idle position and a full throttle position. A biasing mechanism extends between the pedal arm and the bracket for urging the pedal arm to the idle position. A friction disc engages the biasing mechanism for movement therewith. The friction disc is in frictional engagement with a stationary friction plate for relative movement therebetween. Movement of the pedal arm from the idle position towards the full throttle position responsively rotates the friction disc relative to the friction plate and the biasing mechanism responsively increases frictional engagement between the friction disc and the friction plate by urging the friction disc and friction plate together.
Description




FIELD OF INVENTION




This invention relates to an improved accelerator pedal. In particular, this invention relates to an accelerator pedal for electronic control of a vehicle engine having improved hysteresis characteristics.




BACKGROUND OF INVENTION




Automotive engines utilizing electronic throttle control systems are now more common than conventional carbureted engines. In a carbureted engine, the accelerator pedal is connected to the throttle valve by a cable. Depressing the pedal rotates the throttle valve against the action of a return spring. The carbureted engine throttle control has established a certain “feel” for engine speed and acceleration. However, with electronic throttle control systems, a cable connection to the carburetor is no longer required, yet the same “feel” for acceleration is still desired.




U.S. Pat. No. 4,944,269 attempts to address the problem of an accelerator pedal for an electronic which produce sufficient hysteresis to the pedal shaft thereby producing the “feel” of a carbureted engine. This accelerator pedal utilizes three springs and numerous components making such an accelerator pedal relatively expensive to manufacture and assemble.




SUMMARY OF THE INVENTION




The disadvantages of the prior art may be overcome by providing an accelerator pedal having minimal of components which produces the desired hysteresis characteristics.




It is desirable to provide an accelerator pedal assembly having a mounting bracket and a pedal arm mounted to the bracket. The pedal arm pivots between an idle position and a full throttle position. A biasing mechanism extends between the pedal arm and the bracket for urging the pedal arm to the idle position. A friction disc engages the biasing mechanism for movement therewith. The friction disc is in frictional engagement with a stationary friction plate for relative movement therebetween. Movement of the pedal arm from the idle position towards the full throttle position responsively rotates the friction disc relative to the friction plate and the biasing mechanism responsively increases frictional engagement between the friction disc and the friction plate by urging the friction disc and friction plate together.




It is desirable to provide an accelerator pedal assembly comprising a mounting bracket, a pedal arm and a biasing mechanism. The arm is pivotally mounted to the bracket for movement between an idle position and a full throttle position. The biasing mechanism comprises a first coil extending between the pedal arm and the bracket, a second coil extending between the pedal arm and the bracket. The first coil engages and responsively rotates a first friction disc against a friction plate which mounted to the bracket. The second coil engages and responsively rotates a second friction disc against the friction plate. The biasing mechanism biases the arm to the idle position. As the arm is rotated towards the full throttle position, frictional resistance to the movement is produced by the first and second friction discs frictionally engaging the friction plate.




It is desirable to provide an accelerator pedal assembly comprising a mounting bracket, a pedal arm and a biasing mechanism. The arm is pivotally mounted to the bracket for movement between an idle position and a full throttle position. The biasing mechanism comprises a first coil extending between the pedal arm and the bracket. The first coil engages and responsively rotates a first friction disc against a friction plate which mounted to the bracket and a second friction disc mounted for frictional rotation relative to the arm. The biasing mechanism biases the arm to the idle position. As the arm is rotated towards the full throttle position, frictional resistance to the movement is produced by the first friction disc frictionally engaging the friction plate and by the second friction disc frictionally engaging the arm.











DESCRIPTION OF THE DRAWINGS




In drawings which illustrate an embodiment of the invention,





FIG. 1

is a side elevational view of a accelerator pedal of the present invention;





FIG. 2

is a perspective view of a biasing mechanism of the accelerator pedal of

FIG. 1

; and





FIG. 3

is an exploded perspective view of a second embodiment of the present invention.











DESCRIPTION OF THE INVENTION




Referring to

FIG. 1

, there is illustrated an accelerator pedal assembly


10


of the present invention. The pedal assembly generally comprises a pedal arm


12


, a mounting bracket


14


and a biasing mechanism


16


.




Arm


12


is conventional in construction. Arm


12


is elongate and pivotally mounted to the bracket


14


at one end and has a pad


18


at an opposite distal end. The pivoted end has side spaced flanges


17


for pivotally mounting to the bracket


14


. Arm


12


has stops


19


and


21


which limit the pivotal travel of the arm


12


.




Bracket


14


is preferably a U-shape stamped and formed to present side flanges


23


between which the biasing mechanism


16


extends and pivotally mounts the arm


12


. The mounting face


20


has a centrally located aperture


22


.




Stop


19


contacts the mounting face


20


when the arm


12


is in the idle or stand-by position. Stop


19


contacts the mounting face


20


when the arm


12


is in the full throttle position. Biasing mechanism


16


biases arm


12


to the idle or stand-by position.




Referring to

FIG. 2

, the biasing mechanism


16


is illustrated in greater detail. The biasing mechanism


16


generally comprises a single spring


24


, discs


26


,


28


,


30


,


32


, spindle


34


, bushings


36


,


38


, washers


40


and friction plate


42


.




Spring


24


is a double wound spring defining first and second coils


44


,


46


, tab


48


and ends


50


and


52


. Spring


24


is wound symmetrically and in opposite senses taking the midpoint of tab


48


as the reference. The diameter of coils


44


,


46


enables the spring to be mounted on spindle


34


. Coils


44


,


46


have an axial extent such to be slightly less than the spacing between flanges


17


of arm


12


.




Discs


26


,


28


,


30


,


32


are identical, thereby minimizing part count. The discs are preferably stamped and formed from sheet steel. Each disc has a hub


56


for mounting on spindle


34


, four radially extending ribs


54


extending between hub


56


and an outer rim


58


. The convex side of the web between the hub


56


and outer rim


58


presents a friction surface


60


. At least one of area of the outer rim has a cut out


62


defining two tangs which frictionally engage the spring


24


.




The discs are mounted on the spindle


34


such that the friction surface


60


on discs


26


and


32


engage the side flanges


17


of the arm


12


and on discs


28


and


30


face each other. Coils


46


,


44


engage discs


26


,


28


and


30


,


32


, respectively producing the desired frictional resistive forces. The ends


50


,


52


hold discs


32


,


26


respectively to allow the discs


32


,


26


to rotate relative to the arm


12


as it rotates between the idle position and the full throttle position.




Spindle


34


extends from the side flanges of the bracket


14


to pivotally mount arm


12


. Bushings


36


,


38


and washers


40


journal mount the spindle


34


on the bracket


14


. One end of spindle


34


has a flattened tab


66


which is configured to engage a throttle control device as described in U.S. Pat. Nos. 5,133,321; 5,321,980. The throttle control device is coupled to the electronic ignition module for controlling the speed of the engine.




Friction plate


42


has a generally circular shape with a central bore for mounting on spindle


34


. The plate


42


has a tab


64


which extends into aperture


22


of bracket


14


and is thus restrained from rotating. The plate


42


is sandwiched between discs


28


and


30


which is sandwiched between coils


44


,


46


and within tab


48


.




The strength of the spring


24


and diameter of the friction plate


42


and the discs


26


,


30




28


,


30


,


32


are selected to produce a desired amount of frictional forces.




Once assembled, tab


48


will engage arm


12


and ends


52


,


54


of spring


24


will engage the bracket


14


. Spring


24


biases arm


12


of the pedal assembly


10


outwardly to the idle engine speed position. Stop


21


engages the bracket


14


. As the operator presses on pad


18


, tab


48


of spring


24


will be rotated. The tab


48


will responsively rotate the discs


28


and


30


. The discs


28


,


30


will rotate relative to plate


42


providing frictional resistance to the operator's foot movement. Additionally, rotation of the arm


12


winds coils


44


,


46


which urges the discs


26


,


28


and


30


,


32


apart thereby increasing frictional forces. Continued pressure will rotate the arm


12


to the full throttle position where stop


19


will engage the bracket.




On release of pressure from the operator's foot, the spring


24


will urge the arm


12


back towards the idle engine speed position, the coils


44


,


46


will unwind, releasing the friction engagement of the discs


26


,


28


,


30


and


32


.




Thus, as the operator presses on the pad


18


, the resistance to the pressure increases and as the operator releases the pressure the pedal returns smoothly without resistance thereby simulating the “feel” of a carbureted engine accelerator pedal.




In the preferred embodiment, the spring


24


is illustrated and described as a single spring. It is now apparent to those skilled in the art that the spring could be replaced by two springs, each wound in an opposite sense as the other. Additionally, a suitable accelerator pedal could be made using a single coil spring


146


engaging at least one disc


28


which is sized to produce sufficient frictional forces. The arm


12


has a pair of spaced flanges


17


and the bracket


14


has a pair of spaced flanges


23


. The arm


12


is mounted in an offset relation with the bracket


14


and the disc


28


acts against one of the bracket flanges


23


as illustrated in FIG.


3


. However, current safety regulations in North America require that the accelerator assembly have at least two springs or coils and thus a second spring will be required.




The above-described embodiment of the invention is intended to be an example of the present invention and alterations and modifications may be effected thereto, by those of skill in the art, without departing from the scope of the invention.



Claims
  • 1. An accelerator pedal assembly comprising:a mounting bracket, a pedal arm mounted to the bracket for pivotal movement between an idle position and a full throttle position, a biasing mechanism extending between the pedal arm and the bracket for urging said pedal arm to the idle position, said biasing mechanism comprises a coil having a first and second ends with said second end engaging the mounting bracket, a stationary friction plate, a first friction disc engaging said first end of said coil for movement therewith, said first friction disc in frictional engagement with said friction plate, a second friction disc engaging said second end of said coil, said second friction disc frictionally engaging said pedal arm, wherein movement of said pedal arm from said idle position towards said full throttle position responsively rotates said first friction disc relative to said friction plate and said biasing mechanism responsively increases friction engagement between the first friction disc and the friction plate and said movement of said pedal arm winds said coil to axially extend said coil urging said first friction disc axially and thereby effect said increase in frictional engagement between said first friction disc and said friction plate.
  • 2. An accelerator pedal assembly as claimed in claim 1 wherein said friction plate engages said bracket.
  • 3. An accelerator pedal assembly as claimed in claim 1 wherein said friction plate is integral with said bracket.
  • 4. An accelerator pedal assembly as claimed in claim 1 wherein said assembly further comprises a spindle on which said pedal is mounted, said spindle having an end adapted for operative engagement with an electronic speed control device.
  • 5. An accelerator pedal assembly comprising:a mounting bracket, a pedal arm mounted to the bracket for pivotal movement between an idle position and a full throttle position, a biasing mechanism extending between the pedal arm and the bracket for urging said pedal arm to the idle position, a stationary friction plate, a first friction disc engaging said biasing mechanism for movement therewith, said first friction disc in frictional engagement with said friction plate, movement of said pedal arm from said idle position towards said full throttle position responsively rotates said first friction disc relative to said friction plate and said biasing mechanism responsively increases friction engagement between the first friction disc and the friction plate, and said biasing mechanism comprises a first coil having a first end engaging said first friction disc and a second end engaging the mounting bracket and a second coil having a first end engaging a second friction disc and a second end engaging the mounting bracket, said second friction disc in frictional engagement with said friction plate on a side thereof opposite said first friction disc, said movement of said pedal arm winds said coil to axially extend said coils urging said friction discs axially and thereby effect said increase in frictional engagement between said friction discs and said friction plate.
  • 6. An accelerator pedal assembly as claimed in claim 5 wherein said assembly further comprises a third friction disc engaging said second end of said first coil, said third friction disc frictionally engaging said pedal arm, and a fourth friction disc engaging said second end of said second coil, said fourth friction disc frictionally engaging said pedal arm.
  • 7. An accelerator pedal assembly as claimed in claim 6 wherein said first and second coils are commonly wound and integral with each other.
  • 8. An accelerator pedal assembly as claimed in claim 7 wherein said first coil and said second coil are wound in opposite senses.
  • 9. An accelerator pedal assembly as claimed in claim 8 wherein said friction plate engages said bracket.
  • 10. An accelerator pedal assembly as claimed in claim 8 wherein said friction plate is integral with said bracket.
  • 11. An accelerator pedal assembly as claimed in claim 5 wherein said assembly further comprises a spindle on which said pedal is mounted, said spindle having an end adapted for operative engagement with an electronic speed control device.
Parent Case Info

This application claims benefit of Provisional No. 60/130,366 filed Apr. 21, 1999.

US Referenced Citations (16)
Number Name Date Kind
3875820 Morden Apr 1975 A
4516439 Sagaser May 1985 A
4528590 Bisacquino et al. Jul 1985 A
4779713 Tomala et al. Oct 1988 A
4850242 Hass et al. Jul 1989 A
4944269 Imoehl Jul 1990 A
5133321 Hering et al. Jul 1992 A
RE34301 Imoehl Jul 1993 E
RE34302 Imoehl Jul 1993 E
RE34574 Imoehl Apr 1994 E
5321980 Hering et al. Jun 1994 A
5335563 Yamamoto et al. Aug 1994 A
5385068 White et al. Jan 1995 A
5408899 Stewart Apr 1995 A
5868040 Papenhagen et al. Feb 1999 A
6250176 Reimann et al. Jun 2001 B1
Foreign Referenced Citations (3)
Number Date Country
4-19256 Jan 1992 JP
4-50064 Feb 1992 JP
4-232158 Aug 1992 JP
Provisional Applications (1)
Number Date Country
60/130366 Apr 1999 US