Accelerator pedal for vehicle incorporating liquid nanofoam

Abstract

An accelerator pedal assembly including an accelerator pedal attached to the driver's compartment of a vehicle is disclosed. The accelerator is reversibly movable between the neutral or idling position when no pressure is applied to the pedal and an acceleration position when pressure is applied. The assembly includes a compression assembly having a compression chamber with a piston, liquid nanofoam in the chamber, and a geared driver assembly connecting the compression assembly and the pedal. When the pedal is depressed, the driver assembly is activated, forcing the piston into the chamber and causing the force level to rise until it reaches the designed load limit or the threshold. When the pressure on the pedal is relieved, the position of the pedal is immediately reset to the neutral position as the piston is pushed out of the chamber by internal pressure generated by liquid escaping the nanoporous material via the nanopores.

Claims

1. An accelerator pedal assembly for use in a vehicle, the assembly comprising: an accelerator movably attached to the vehicle; a compression assembly including a compression chamber, a piston at least partially fitted within said chamber, a liquid nanofoam within said chamber; and a geared driver assembly comprising a rack extending from said piston and a pinion gear engaged with said rack, said geared driver assembly connecting said compression assembly with said accelerator.

2. The accelerator pedal assembly of claim 1, wherein said liquid nanofoam comprises a liquid having a suspension of nanoporous material.

3. The accelerator pedal assembly of claim 1, wherein said accelerator includes a pedal and a pedal arm, said pedal arm having a first axis.

4. The accelerator pedal assembly of claim 3, further including a rotary shaft extending from said pedal arm, said rotary shaft being perpendicular to said first axis of said pedal arm.

5. The accelerator pedal assembly of claim 4, wherein said pinion gear is attached to said rotary shaft.

6. The accelerator pedal assembly of claim 1, further including a fluid seal between said piston and said chamber.

7. The accelerator pedal assembly of claim 1, wherein a seal is formed between said piston and said chamber, said seal being selected from the group consisting of an O-ring and a piston ring.

8. An accelerator pedal assembly for use in a vehicle, the assembly comprising: an accelerator movably attached to the vehicle; a compression assembly including a compression chamber having a movable surface, said chamber having an interior volume that is changed by the position of said movable surface, said chamber enclosing a nanoporous material and a liquid; and a drive assembly comprising a rack extending from said moveable surface and a pinion gear engaged with said rack, said drive assembly connecting said movable surface and said accelerator.

9. The accelerator pedal assembly of claim 8, wherein said nanoporous material and said liquid define a liquid nanofoam.

10. The accelerator pedal assembly of claim 8, further including a piston having a compression end, said compression end defining said movable surface.

11. The accelerator pedal assembly of claim 10, wherein said accelerator includes a pedal and a pedal arm, said pedal arm having a first axis.

12. The accelerator pedal assembly of claim 11, further including a rotary shaft extending from said pedal arm, said rotary shaft being perpendicular to said first axis of said pedal arm.

13. The accelerator pedal assembly of claim 12, wherein said pinion gear is attached to said rotary shaft.

14. The accelerator pedal assembly of claim 10, further including a fluid seal between said piston and said chamber.

15. The accelerator pedal assembly of claim 14, wherein said seal is selected from the group consisting of an O-ring and a piston ring.

16. A method of generating a reversible force-stroke response curve in a vehicle accelerator, the response curve demonstrating no dissipation between acceleration and deceleration, the method comprising: forming an accelerator pedal assembly comprising an accelerator pedal movable between a neutral position and an accelerating position, a compression assembly including a compression chamber, a piston at least partially fitted within said chamber, a liquid nanofoam having a suspension of nanoporous material, within said chamber, and a geared driver assembly connecting said compression assembly with said accelerator pedal, said geared driver assembly comprising a rack extending from said piston and a pinion gear engaged with said rack; applying pressure on said accelerator pedal to move it from said neutral position to said accelerating position thereby moving said piston into said chamber and causing the force level to rise until reaching a threshold pressure; and removing said pressure from said accelerator pedal allowing said piston to be pushed out of said chamber by internal pressure generated by said liquid nanofoam thereby returning said accelerator pedal to said neutral position.

17. The method of claim 16, wherein said threshold pressure is between 0.5 Mpa and 50 Mpa.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a more complete understanding of this invention, reference should now be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention wherein:

(2) FIG. 1 is a side, diagrammatic view of an accelerator pedal assembly according to a known design;

(3) FIG. 2 is a perspective view of the accelerator pedal assembly of FIG. 1 according to a known design;

(4) FIG. 3 is a perspective view of an accelerator pedal assembly according to the disclosed inventive concept;

(5) FIG. 4 is another perspective view of the accelerator pedal assembly according to FIG. 3;

(6) FIG. 5 is a detailed view shown in partial section of the gear, rack, and piston arrangement of the accelerator pedal assembly of the disclosed inventive concept shown in conjunction with the liquid nanofoam-filled cylinder;

(7) FIG. 6 is another detailed view of the gear, rack, and piston arrangement of the accelerator pedal assembly of the disclosed inventive concept shown in conjunction with the liquid nanofoam-filled cylinder where the pedal arm is in a neutral position;

(8) FIG. 7 is a view similar to that of FIG. 6 but illustrating the cylinder where the pedal arm is in an accelerating position; and

(9) FIG. 8 is a force-stroke response curve illustrating force along the y-axis and stroke along the x-axis.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(10) In the following figures, the same reference numerals will be used to refer to the same components. In the following description, various operating parameters and components are described for different constructed embodiments. These specific parameters and components are included as examples and are not meant to be limiting.

(11) The accompanying figures illustrate an arrangement for providing an accelerator assembly for use with a vehicle in which the accelerator assembly includes a piston and cylinder assembly attached to an accelerator pedal. The piston and cylinder assembly includes a liquid nanofoam that is capable of returning the pedal to the neutral position following acceleration with virtually no delay in the return rate. The accelerator assembly disclosed herein may be readily adapted for any vehicle that requires a foot pedal for use as an accelerator. The accelerator assembly is relatively inexpensive to produce and has a high rate of durability with virtually no sign of wear even after repeated and intensive operator use. It is to be understood that the illustrated accelerator assembly is not to be restricted to the configuration shown in the figures which is intended as being illustrative without being limiting.

(12) Referring to FIGS. 3 and 4, perspective images of a liquid nanofoam accelerator pedal assembly according to the disclosed inventive concept are illustrated. The liquid nanofoam accelerator pedal assembly, generally illustrated as 20, includes an assembly attachment base 22 that is generally attached in the area of the driver's footwell of the vehicle. The attachment point can be on the floor or in association with the instrument panel. The assembly attachment base 22 is provided for illustrative purposes only and is not intended as being limiting as the liquid nanofoam accelerator pedal assembly 20 may be fitted at any point to provide for functional use of the associated pedal.

(13) The liquid nanofoam accelerator pedal assembly 20 includes a pedal arm 24 movably attached to the assembly attachment base 22. The pedal arm 24 includes a foot pedal 26 at one end. A liquid nanofoam drive assembly 28 is incorporated with the liquid nanofoam accelerator pedal assembly 20. The liquid nanofoam drive assembly 28 is operatively associated with the pedal arm 24. The illustrated arrangement of operative attachment includes a rotary drive gear 30 that is attached by a rotary shaft to the pedal arm 24.

(14) The rotary drive gear 30 includes an array of drive teeth that operatively engage the drive teeth provided on an elongated rack 32. In combination, the rotary drive gear 30 and the elongated rack 32 define a rack-and-pinion mechanism. One end of the elongated rack 32 is fixed to a reciprocating piston 34. The reciprocating piston 34 is the movable drive component of a liquid nanofoam-filled cylinder 36 that is fixed to the assembly attachment base 22. As illustrated, the drive teeth of the rotary drive gear 30 mesh with the drive teeth of the elongated rack 32.

(15) A sectional view of the liquid nanofoam drive assembly 28 is illustrated in FIG. 5. With reference thereto, the liquid nanofoam drive assembly 28 includes elements for providing a sealing relationship between the reciprocating piston 34 and the inner surface of the liquid nanofoam-filled cylinder 36. The sealing elements may be either or both a set of O-rings 38 and 38 or a set of piston rings 39 and 39.

(16) A predetermined volume of hydrophobic nanoporous material 40 is suspended in a liquid carrier 42. The hydrophobic nanoporous material 40 include spheres having nanopores formed in their outer surfaces. Under ambient pressure, the individual spheres are effectively void of the liquid due to the excessive solid-liquid interfacial tension. However, when pressure is applied by the driver's foot against the foot pedal 26, this pressure is translated to movement of the reciprocating piston 34 into the liquid nanofoam-filled cylinder 36. Under a predetermined pressure level, the surface tension is overcome and the surrounding fluid is forced into the individual spheres. Movement of the reciprocating piston 34 into the liquid nanofoam-filled chamber 36 thus continues, causing the vehicle's engine throttle control to accelerate the movement of the vehicle.

(17) When the driver's foot is removed from the foot pedal 26, the pressure on the reciprocating piston 34 is released and the liquid moves out of the spheres forming the hydrophobic nanoporous material 40 force the reciprocating piston 34 and consequently the foot pedal 26 to their original idle positions.

(18) FIGS. 6 and 7 illustrate the liquid nanofoam drive assembly 28 in its idle position and in its accelerating position respectively. Referring to FIG. 6, the pedal arm 24 is shown rotated to its neutral or idle position. In this position, the reciprocating piston 34 is at the bottom of its range relative to the liquid nanofoam-filled cylinder 36.

(19) Upon acceleration, the pedal arm 24 is rotated thus causing the rotary drive gear 30 to rotate thereby creating linear movement in the elongated rack 32 to thereby drive the reciprocating piston 34 into the liquid nanofoam-filled cylinder 36 as illustrated in FIG. 7. In this position, some of the liquid carrier 42 is forced into the voids of the spheres of the hydrophobic nanoporous material 40 as discussed above.

(20) FIG. 8 graphically illustrates the force-stroke response curve generated by operation of the liquid nanofoam accelerator pedal assembly 20. Force is illustrated on the Y-axis and stroke on the X-axis. The graph demonstrates the load limiting force that is exhibited due to the direct compression of the liquid nanofoam due to the stroke of the reciprocating piston 34 as driven by the linear movement of the elongated rack 32. As illustrated, the load-response of the liquid nanofoam accelerator pedal assembly 20 is reversible while demonstrating no dissipation.

(21) One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the invention as defined by the following claims.