This invention pertains generally to a vehicle pedal and, more specifically, to a pedal resistance mechanism and module for a vehicle accelerator pedal assembly.
Some vehicle pedal assemblies in use today are mechanical, typically incorporating a cable or various gears and other transmission devices which convert rotary motion from the pedal into useful mechanical motion. Other pedal assemblies incorporate a position sensor that converts the mechanical position into an electrical signal. In the field of automobiles and trucks, a mechanical bracket using a cable, often referred to as a Bowden cable, is one of the methods used for controlling the throttle of internal combustion engines. These pedal assemblies have a desirable feel and functionality and, with a few refinements, are extremely reliable.
Other pedal assemblies in use today include an electrical linkage between the pedal and the device to be controlled instead of a cable. An electrical linkage is desirable since gear assemblies are bulky, expensive, and limited, due to their inherent size, to those applications where the pedal is very close to the controlled device. While the Bowden cable has proved generally reliable, the penetration of moisture and other contaminants may cause the cable to bind or freeze up during inclement weather.
The substitution of cables with electrical sensors, however, resulted in a poor tactile feel for the operator because the pedal was no longer attached to any mechanical assembly like the cable that provided the required friction and resistance to overcome during operation. Since operators were accustomed to the feel of a mechanical pedal, it has proven desirable to continue this feeling in electronic pedals by incorporating a resistance or kickdown mechanism or module of the type disclosed in, for example, U.S. Pat. No. 6,418,813 to Lewis and assigned to CTS Corporation.
The present invention is directed to an improved resistance or kickdown mechanism and module for a vehicle pedal assembly.
The present invention is directed generally to a resistance mechanism for a pedal assembly.
The resistance mechanism initially comprises a plunger adapted for depression and linear movement in response to the application of a compressive force thereto and the plunger includes an exterior camming surface. The resistance mechanism also comprises an actuator which includes an exterior camming surface which abuts the camming surface on the plunger and is adapted for linear movement in response to the linear movement of the plunger. The resistance mechanism still further comprises a biasing device which abuts against the actuator and is adapted to apply a biasing force against the actuator.
According to the invention, the camming surfaces on the plunger and the actuator respectively slide against each other in response to the compression force applied to the plunger and the biasing force applied against the actuator to allow the creation and adjustment of a resistance force which is applied by the plunger to the pedal assembly.
In one embodiment, the resistance mechanism comprises a separate module or cartridge which defines an interior housing for the plunger, the actuator, and the biasing device and the module is fitted in the interior of a cavity defined in the pedal of the pedal assembly.
In one embodiment, the plunger and the actuator are both adapted for linear movement within first and second respective cavities defined in the module and the actuator is disposed in the second cavity in the module at an angle relative to the plunger in the first cavity of the module.
Further, in one embodiment, the plunger includes respective proximal and distal ends. The proximal end projects out of an opening defined in one of the walls of the module and the distal end projects out of an opening defined in another of the walls of the module. The camming surface is defined on a side surface of the plunger. The actuator includes respective interior and exterior surfaces. The camming surface on the actuator is defined on the exterior surface and the biasing device abuts against the interior surface of the actuator.
Still further, in one embodiment, the module defines an interior surface and the actuator includes at least first and second arms each of which includes an exterior surface adapted to slide against the interior surface of the module.
Additionally, in one embodiment, the respective camming surfaces on the plunger and the actuator each include a plurality of interconnected sloped segments which interact and cooperate with each other to generate the resistance force which is applied by the plunger to the pedal.
In one embodiment, at least two of the plurality of camming segments on the plunger abut and slide against at least two of the plurality of camming segments on the actuator.
There are other advantages and features of this invention which will be more readily apparent from the following detailed description of the embodiment of the invention, the drawings, and the appended claims.
In the accompanying drawings that form part of the specification, and in which like numerals are employed to designate like parts throughout the same:
Resistance or kickdown mechanism and module 10 has a generally rectangularly-shaped housing or case or cartridge 20 which, in one embodiment, is adapted to be press-fitted and retained in the interior cavity 250 defined in the underside surface 220 of a pedal arm 200 of the type shown in
Referring back to
The end wall 34 (FIGS. 1 and 5-9) defines an elongate opening (not shown) for the finger 88 of a plunger 70 as described in more detail below. The front wall 30 defines an opening 31 including a narrow region 33 and a wide region 35. The opening 31, which extends and slopes downwardly at about a 45 degree angle from a point adjacent the upper left corner of the housing 20 and the end wall 34 thereof to a point adjacent the lower diametrically opposed right corner of the housing 20 and the opposed end wall 36 thereof, leads into a bore or cavity 38 (FIGS. 1 and 5-9) which is defined in the interior of the housing 20.
The bore 38 is defined by at least lower and upper opposed, spaced-apart and generally parallel interior surfaces 39 and 41 respectively which also extend and slope downwardly at about a 45 degree angle between the opposed end side walls 34 and 36.
A generally square-shaped opening 44 (FIGS. 1 and 5-9) is defined in the top wall 26 adjacent the edge of the housing 20 which joins the end wall 34 and the top wall 26. Opening 44 extends into a generally vertically oriented cavity 53 (
The top wall 26 additionally defines a smaller opening 48 (
The resistance or kickdown mechanism and module 10 additionally comprises an elongate, generally square-shaped piston or plunger 70 which is mounted for reciprocating up and down linear movement in and through the opening 44 and the cavity 53 in the housing 20 in a relationship and direction generally normal to the top and bottom housing walls 26 and 28. The plunger 70 may be formed from either molded plastic or machined steel. The plunger 70 includes opposed upper and lower distal spaced-apart ends 72 and 74 respectively (FIGS. 2 and 5-9) and four circumferentially extending side faces including opposed front and back spaced-apart faces 76 and 78 respectively.
The back face 78 of the plunger 70 includes an elongate rib or key 79 (
The plunger 70 is oriented and mounted in the housing 20 in a generally vertical relationship generally normal to the top housing wall 26 and adjacent and parallel to the vertical housing end wall 34. In the normal, disengaged orientation of the resistance mechanism and module 10, the upper end 72 of the plunger 70 protrudes out of the housing 20 and, more specifically, out of the opening 44 defined in the top wall 26 thereof. The body of the plunger 70 extends through the interior housing cavity 53. The lower end 74 and, more specifically, the finger 88 of the plunger 70 protrudes outwardly from the opening (not shown) defined in the end wall 34 of the housing 20 as shown in
As shown in greater detail in FIGS. 2 and 5-9, the front face 76 of the plunger 70 includes a camming surface 80 which slopes and angles simultaneously rearwardly in the direction of the back face 76 of the plunger 70 and downwardly in the direction of the lower end 74 of the plunger 70 at about a 45 degree angle relative to the front face 76 of the plunger 70. In the embodiment shown, the camming surface 80 starts at a point generally midway along the front face 76 and terminates at a point adjacent the lower end 74 of the plunger 70.
The plunger camming surface 80 has a plurality of angled, generally flat interconnected camming surfaces or segments 82, 84, and 86. Segment 82 is angled and slopes simultaneously inwardly and downwardly from the generally vertical front face 76 of the plunger 70 in the direction of the back vertical wall 78 and the distal end 74 of the plunger 70; the segment 84 is angled and slopes further simultaneously inwardly and generally downwardly from the lower edge of the segment 82 also in the direction of the back plunger face 78 and the distal end 74 thereof; and the segment 86 is angled and slopes simultaneously rearwardly and downwardly from a lower edge of segment 86 also in the direction of the back vertical wall 78 and into the distal end 74 of the plunger 70.
Thus, in the depicted embodiment, the angled segments 82 and 86 define respective end camming segments disposed and oriented at the same angle relative to the front and back plunger faces 76 and 78 and thus are designed and oriented relative to each other in a generally spaced and parallel relationship. Camming segment 84 extends between the camming segments 82 and 86 at an angle different than the segments 82 and 86.
With continued reference to FIGS. 2 and 5-9, resistance mechanism and module 10 additionally comprises a biasing device in the form of a coil spring 94 which is also located in the bore or cavity 38 of the housing 20 and, as described in more detail below, is adapted to exert a biasing force against an actuator 100 which, in turn, biases the plunger 70 out of the cavity 53 and the housing 20. Spring 94 has opposed proximal and distal ends 96 and 98 respectively. Distal end 98 rests against a sloped interior end housing wall 42 (
As discussed briefly above, the resistance mechanism and module 10 additionally comprises a generally unitary U-shaped actuator 100 (FIGS. 2 and 5-9) including diametrically opposed arms 102 and 104 extending generally normally outwardly from the opposed ends of a central base 106 and further including an exterior camming surface 107 (FIGS. 2 and 5-9). The interior surface of each of the arms 102 and 104 is generally concave and adapted to receive and cradle the distal end 96 of the spring biasing device 94. Actuator 100 can be formed from metal or plastic.
The actuator 100 is introduced into the housing 20 during the assembly process through the wide region 35 of the opening 31 in the front wall 30 of the housing 20 and is pushed inwardly and upwardly into the bore 38 of housing 20 into a relationship wherein the exterior camming surface 107 thereof is abutted against the exterior camming surface 80 defined on the front face 76 of the plunger 70 as shown in
Also, during the assembly process, the coil spring 94 is introduced into the housing 20 through both the narrow and wide regions 33 and 35 defined in the opening 31 into the relationship as described above wherein the end 96 rests against the interior surface of the base 106 and is cradled between the arms 102 and 104 of the actuator 100, and the opposed distal end 98 is abutted against the surface of the interior housing wall 42.
In the embodiment shown, the exterior camming surface 107 of the actuator 100 includes four differently flat and interconnected camming surface segments 110, 112, 114, and 116 (FIGS. 2 and 5-9) of which the segments 112 and 114 are adapted to interact with and slide against the camming segments 82 and 84 on the camming surface 80 of the plunger 70 as described in more detail below.
Segment 110 extends generally downwardly and outwardly from an inside edge of the exterior surface of the upper arm 102 of the actuator 100. The segment 112 extends generally outwardly and downwardly from a lower edge of the segment 110. The segment 114 extends generally downwardly from a lower edge of the segment 112 in the direction of the lower arm 104. The segment 116 extends generally inwardly and downwardly from a lower edge of the segment 114 and terminates in an inside edge of the exterior surface of the lower arm 104 of the actuator 100.
In accordance with the invention, actuator camming segments 110 and 112 on the actuator 100 are disposed and oriented at the same angle and slope relative to each other and also at the same angle and slope as the camming segment 84 on the camming surface 80 of the plunger 70. The actuator camming segment 114 is disposed and oriented at the same angle and slope as the camming segment 86 on the camming surface 80 of the plunger 70. Moreover, in the embodiment shown, the actuator camming segments 110 and 112 on the one hand and the actuator camming segment 116 on the other hand diverge away from each other and the upper and lower edges respectively of the central actuator camming segment 114.
Referring to
The spring 94 has a natural biasing force which urges or moves the plunger 70 outwardly out of the housing 20 when no external compressive force is applied to the end 72 of the plunger 70.
In the extended or rest position of the resistance mechanism and module 10 and the plunger 70 as shown in
When a large enough magnitude external compressive force is applied against the end 72 of the plunger 70 (as a result of the depression of the pedal arm 200 into contact with the stop 350 on the base 340) to overcome the combination of the opposed biasing force of the spring 94, the friction force between the abutting plunger and actuator camming surfaces 84 and 112 respectively, and the opposing friction forces between abutting actuator and interior housing surfaces and arms 39 and 104 respectively and 41 and 102 respectively, the plunger 70 is depressed (i.e., is moved linearly inwardly and downwardly into the cavity 53 in the housing 20 a distance of about 0.5 mm) as shown in
The depression of the plunger 70 as shown in
In accordance with the present invention, the angle and slope of the abutting camming segments 84 and 112 in part determines the magnitude of the compressive force which will be necessary to overcome the biasing and friction forces as described above and cause the movement of the plunger 70 into the housing 20.
Also, when the plunger 70 is depressed, the interaction between at least the respective abutting plunger and actuator camming surfaces, the spring biasing force, and the surface friction forces as described above, causes the pedal resistance mechanism and module 10 to create and generate a pedal resistance force that is transmitted through the plunger 70 and into the pedal arm 420 and is applied to the foot of the user.
As shown in
The continued depression of the plunger 70 a distance of about 1 mm inward into the cavity 53 as shown in
As shown in
The still continued depression of the plunger 70 a distance of about 1.5 mm inwardly into the cavity 53 as shown in
In the position of
Although not shown in any of the FIGURES, it is understood that the release of the compressive force applied against the plunger 70 (through the release of pressure on the pedal arm 200) causes the spring 94 and, more specifically, the biasing force therein, to move the plunger 70 back up to its original rest or stop position as shown in
A graph of pedal force versus travel of the plunger 70 for the module 10 is shown in
The lower graph line 600 is a representation of the pedal force versus plunger travel effect for module 10 as a user removes pressure from the pedal arm 200 thus removing pressure on the plunger 70 and causing the plunger 70 to move from its
With continued reference to
The region 504 on the graph line 500 depicts the increase in the pedal resistance force (i.e., the force acting against the foot of the vehicle operator and against the depression of the pedal) which occurs between 0 mm and 1 mm of travel of the plunger 70 linearly inwardly and downwardly into the cavity 53 of the housing 20 as shown in
The point 505 on the graph line 500 represents the peak or highest point or magnitude of the pedal resistance force which occurs when the plunger 70 and the actuator 100 and, more specifically, the respective camming segments 84 and 114, are abutted against each other as shown in
The region 506 on the graph line 500 exhibits the first sharp vertical drop-off in pedal resistance force which occurs between the plunger position of
The region 510 on the graph line 500 exhibits the second sharp drop-off in the pedal resistance force when the plunger 70 has completely overcome the biasing force of the coil spring 94, the friction force of the abutting plunger and actuator camming surfaces, and the friction force of the abutting actuator and housing surfaces.
The region 602 on the graph line 600 exhibits the slight but continued drop-off in pedal resistance force as the plunger 70 travels back out of the housing 20 from its
The region 606 on the graph line 600 exhibits the reduction in the pedal resistance force as the plunger 70 is moved rearwardly out of the housing from its
Numerous variations and modifications of the embodiment described above may be effected without departing from the spirit and scope of the novel features of the invention. It is thus understood that no limitations with respect to the specific mechanism and module illustrated herein are intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.
For example, it is understood that the invention also covers the embodiment wherein the plunger 70, the actuator 100, and the coil spring 95 are all appropriately located, mounted and interconnected directly in the cavity 250 of the pedal arm 220 rather than in a separate housing 20. It is also understood that the module 10 and/or the plunger 70, the actuator 100, and the coil spring 95 could also be located and mounted in the base 340 of the vehicle pedal assembly 300 rather than in the pedal arm 220.
This application claims the benefit of the filing date and disclosure of U.S. Provisional Application Ser. No. 61/276,210 filed on Sep. 9, 2009 which is explicitly incorporated herein by reference as are all references cited therein.
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Number | Date | Country | |
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20110056326 A1 | Mar 2011 | US |
Number | Date | Country | |
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61276210 | Sep 2009 | US |