The present invention relates to a pedal system for passenger vehicles having a frictional hysteresis mechanism to provide a desired amount of friction when operating a pedal and also to reduce unwanted back pressure on a driver's foot while operating the pedal. More specifically, the present invention relates to a pedal system with a hysteresis mechanism incorporated therein that facilitates assembly and that is robust, yet that maintains a minimum of components and also optimizes the location and operation of the hysteresis mechanism relative to the pedal lever.
Many of the problems and considerations for pedals with hysteresis devices are elegantly set forth in Staker U.S. Pat. No. 6,523,433, and will not be repeated here. However, further improvement is desired at least in the following areas.
Assembly of hysteresis devices can be challenging, since the spring for the hysteresis device must be compressively pre-tensioned during the assembly process. This results in a condition where the assembler needs “three hands” . . . or at least needs the assistance of a fixture or “extra components” to compressively pre-tension the spring and then hold the tension while the components are assembled. It is desirable to provide a simplified system that is more self-contained and more easily assembled, yet that has less requirement for a fixture or for a tooled “aid” to permit efficient assembly.
There are considerable safety and space-related requirements in the under-dash area of driver pedals. The environment is relatively dirty and subject to significant dust, debris, and moisture, especially at the floor level, and this can adversely affect operation of a hysteresis mechanism over time. It is desirable to protect the hysteresis mechanism and position it away from such a dirty environment, to the extent possible. Also, while the device disclosed in Staker U.S. Pat. No. 6,523,433 is relatively compact, it places the hysteresis device within his pedal beam under a pivot axis of the pedal beam. This can cause the pedal beam to become relatively large below the pedal pivot axis, potentially being “too large” for the space allowed in some pedal applications now being designed by vehicle manufacturers in the area adjacent a vehicle floor board and in front of its engine's firewall. For example, a “thick” pedal requires more room from the foot-engaging surface of the pedal to the vehicle floor. A pedal system is desired that allows the pedal beam to remain relatively smaller in cross-sectional size, especially as it extends downwardly and forwardly from the pedal pivot axis.
Additionally, a pedal system is desired that provides a pivot pin location and support that is both robust and also optimally accessible and well-suited for connection to an electrical device for sensing angular position of the pedal beam. In particular, it is desirable to provide balanced support for the pedal pivot pin where the two side walls of a housing that support the pivot pin are integrally formed and interconnected as part of a unitary molding (as opposed to a multi-piece housing). This assures that the opposing ends of the pivot pin are equally well supported, and also eliminates subassembly operations. Equal support at each end of the pedal pivot pin can be very important in the event of a high-force pedal actuation in a crisis situation, such as urgent actuation of the pedal system during a pending vehicle crash, so that one side does not overpower a second side wall in a manner leading to twisting and unbalanced support of the pedal . . . which would in turn lead to other concerns.
Thus, a system is desired having the aforementioned advantages and solving the aforementioned problems.
In one aspect of the present invention, a pedal system includes a housing comprising a one-piece molding with opposing side walls defining a cavity. An access opening to the cavity opens generally downwardly when the housing is in a vehicle-mounted position. The housing is adapted for attachment to a vehicle. A pedal lever is pivoted to the housing for rotation about a pivot, and a hysteresis mechanism is located above the pivot axis and on an opposite side of the pivot axis from a majority of the pedal lever when the housing is in a vehicle-mounted position. The pedal lever and hysteresis mechanism are shaped to fit into the access opening into operative positions within the housing. By this arrangement, the hysteresis mechanism is positioned in a more protected position from dirt and debris commonly associated with the floor area of vehicles, and further the mechanism is positioned in a region that is more open and less subject to conflicting special requirements within the vehicle.
In another aspect of the present invention, a pedal system includes a housing adapted for attachment to a vehicle, a pedal lever, and a hysteresis mechanism. The housing includes side walls defining a cavity with a closed end and an open end and an internal corner adjacent the closed end. The pedal lever is adapted to fit operably between the side walls of the housing. The hysteresis mechanism is mounted on an end of the pedal lever and adapted to fit through the open end into operative engagement with the closed end, the hysteresis mechanism including a hysteresis lever and a hysteresis spring operably engaging the hysteresis lever, the hysteresis lever including a portion pivotally engaging the internal corner. A pivot pin extends through side walls of the housing and also through the pedal lever to retain the pedal lever in the housing.
In another aspect of the present invention, a pedal system includes a housing defining a cavity, and a pedal assembly shaped to slide into the cavity. The pedal lever has a configured end, and the hysteresis mechanism is pre-assembled onto the configured end. A pivot member pivotally secures the pedal assembly to the housing with the hysteresis mechanism in an operative position for applying a hysteresis force to the pedal when the pedal is operated.
In yet another aspect of the present invention, a method of assembling a pedal system comprises steps of providing a housing adapted for attachment to a vehicle, the housing including side walls defining a closed end and an open end, and providing a pedal lever adapted to fit between the side walls of the housing. The method further includes attaching a hysteresis mechanism to a free end of the pedal lever to form a pedal subassembly, the pedal subassembly being adapted to fit through the open end into operative engagement with the closed end, and installing a pivot pin through side walls of the housing and also through the pedal lever to retain the pedal lever in the housing.
In another aspect of the present invention, a pedal system for a vehicle includes a housing configured for mounting to a vehicle, a pedal lever pivoted to the housing for rotation about a first pivot axis, and a hysteresis mechanism operating between the housing and the pedal lever. The hysteresis mechanism includes at least one rub pad configured to create a sliding hysteresis frictional force when the pedal lever is rotated. The rub pad is movably supported so that the rub pad maintains optimal contact at all times.
In another aspect of the present invention, a pedal system for a vehicle includes a housing configured for mounting to a vehicle, a pedal lever pivoted to the housing for rotation about a first pivot axis, and a hysteresis mechanism including a hysteresis lever operating between the housing and the pedal lever. The hysteresis mechanism further includes a pedal-lever-mounted rub pad and a hysteresis-lever-mounted rub pad configured to create a sliding hysteresis frictional force when the pedal lever is rotated. At least one of the pedal-lever-mounted rub pad and the hysteresis-lever-mounted rub pad are movably supported so that optimal contact is maintained at all times.
These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.
A pedal system 20 (
The illustrated housing 21 (
More specifically, as noted above, the housing 21 (
The illustrated housing 21 is a unitary one-piece molded part of structural plastic, but it is contemplated that it could also be made of metal or other material, depending on functional considerations of the vehicle manufacturer. Since the present pedal system is designed for an accelerator pedal which receives relatively less foot pressure, it is contemplated that plastic will work well. Further, plastic has the advantage that the entire component can be made in a single molding operation, thus reducing secondary operations. Nonetheless, secondary operations can be used as needed. For example, the bearings could be attached at holes 33 in the pedal lever 22 or in the housing if improved bearing properties are desired over the plastic material of the housing 21.
The pedal lever 22 (
The pivot-forming section 52 of pedal lever 22 includes a plurality of radial and circumferential walls 57 and 58 that extend in various directions and at various angles to each other around the pivot hole 60 for distributing and handling stress on the pivot-forming section 52 around pivot pin 32.
The configured end 31 of the pedal lever 22 extends from the pivot-forming section 52 on a side opposite the pedal arm 50 from the pivot axis 23. It also includes various walls and reinforcement ribs as necessary for rigidity. In particular, the configured end 31 includes a cylindrical wall 61 forming a pocket for receiving about half of the spring 41, and also includes an end wall 62 having an arcuately or curvilinearly shaped friction surface 63 on its outboard side. The friction surface 63 can be optimally shaped to provide the frictional resistance in the hysteresis mechanism 24 as the hysteresis lever 40 slides across the friction surface 63, as discussed below. A pair of edge-located L-shaped ridges 64 (
The hysteresis lever 40 (
A modified pedal system 20A (
The pedal system 20A (
It is important that the hysteresis mechanism provide a consistent and desired level of hysteresis friction. However, this is not easily done in an environment next to a vehicle floor, which tends to be dirty and moist. Further, materials that are optimal for creating a durable, consistent sliding friction (i.e. for the frictional rub pads) tend to be more expensive than lower-cost structural plastic materials (i.e. for the pedal lever). This is problematic because, if the entire pedal lever is made of an optimal material for creating a consistent friction, the pedal will be prohibitively expensive. Also, material providing optimal structural integrity (i.e. for the pedal lever) may be different than materials having optimal frictional properties (i.e. for the rub pad). The same conflicting requirements are true for the hysteresis lever and rub pad. Notably, it is contemplated that a modified pedal system may include only one separate rub pad (instead of both pads 100 and 101) if acceptable hysteresis friction can be achieved for a particular application.
The modified pedal lever 22A is a one-piece molded part of structural plastic, and includes a configured end 31A with pocket 61A for receiving a hysteresis spring (not illustrated in
The pedal beam rub pad 100 is configured to matably engage the outer end of the pedal lever 22A, and to form an outer friction surface optimally shaped to provide the frictional resistance in the hysteresis mechanism 24A as the hysteresis lever 40A slides across the friction surface. The pedal beam rub pad 100 includes a body 110 with an arcuate outer surface 111 and arcuate side surfaces 112 and 113 each extending around the pivot axis 23A of the pedal lever 22A. The side surfaces 112 and 113 are angled inwardly toward each other and form the friction surface for engaging mating surfaces on the hysteresis lever rub pad 101. (When engaged by the hysteresis lever rub pad 101, the outer arcuate surface 111 is spaced slightly from the center surface on the hysteresis lever rub pad 101, so that the angled side surfaces are the surfaces that contact each other for providing a frictional hysteresis force.) A pair of ribs 115 on the body 110 fit into the channels 103, with a pair of retainer hooks 116 engaging the top apertures 106. A pair of resilient hooks 117 extend from the body 110 and snappingly engage the bottom apertures 107 to retain the pedal beam rub pad 100 securely on the pedal lever 22A. The surfaces 111-113 extend a length at least as long as the distance of travel when the pedal lever 22A is depressed.
The hysteresis lever 40A is modified to include a pair of strips 120 forming aligned arcuate bearing surfaces 121 facing toward the configured end 31A, and further is modified to include an attachment rod 122 forming a bearing surface 123, with the bearing surfaces 121 and 123 defining a common pivot axis 124. The hysteresis lever rub pad 101 includes a body 125 with a pair of protrusions 126 forming cylindrical bearings (
By this arrangement, optimal materials can be selected for one or both of the pedal beam rub pad 100 and the hysteresis lever rub pad 101 . . . as well as for the pedal lever 22A and the hysteresis lever 40A. For example, it is contemplated that a lubricant impregnated or graphite-containing polymeric material can be chosen for one or both of the rub pads 100 and 101, while a lower-cost structural polymer (potentially glass filled) can be selected for the pedal lever 24A. Also, it is contemplated that the pedal lever and/or the hysteresis lever could be made of metal or other composite material.
It is noted that the hysteresis lever 40A includes a corner-forming section 72A (
It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.
This utility application claims benefit under 35 USC section 119(e) of provisional application Ser. No. 60/731,880, filed Oct. 31, 2005, entitled PEDAL WITH HYSTERESIS MECHANISM, the entire contents of which are incorporated herein.
Number | Name | Date | Kind |
---|---|---|---|
5408899 | Stewart | Apr 1995 | A |
5529296 | Kato et al. | Jun 1996 | A |
5829317 | Vreeken et al. | Nov 1998 | A |
5868040 | Papenhagen et al. | Feb 1999 | A |
5934152 | Aschoff et al. | Aug 1999 | A |
5937707 | Rixon et al. | Aug 1999 | A |
6003404 | Hannewald | Dec 1999 | A |
6070490 | Aschoff et al. | Jun 2000 | A |
6098971 | Stege et al. | Aug 2000 | A |
6109241 | Engelgau | Aug 2000 | A |
6158299 | Czajkowski | Dec 2000 | A |
6240801 | Kojima et al. | Jun 2001 | B1 |
6250176 | Reimann et al. | Jun 2001 | B1 |
6263758 | Kumamoto et al. | Jul 2001 | B1 |
6279883 | Weis | Aug 2001 | B1 |
6289762 | Silva | Sep 2001 | B1 |
6289763 | Rixon et al. | Sep 2001 | B1 |
6298748 | Rixon et al. | Oct 2001 | B1 |
6336377 | Reimann et al. | Jan 2002 | B1 |
6360631 | Wortmann et al. | Mar 2002 | B1 |
6446526 | Reimann et al. | Sep 2002 | B2 |
6450062 | Kojima et al. | Sep 2002 | B2 |
6453768 | Wehner et al. | Sep 2002 | B2 |
6460429 | Staker | Oct 2002 | B1 |
6467370 | Kojima et al. | Oct 2002 | B2 |
6474191 | Campbell | Nov 2002 | B1 |
6520046 | Djordjevic | Feb 2003 | B2 |
6523433 | Staker | Feb 2003 | B1 |
6526844 | Weis | Mar 2003 | B1 |
6553863 | Djordjevic | Apr 2003 | B1 |
6575053 | Menzies | Jun 2003 | B2 |
6591712 | Goto et al. | Jul 2003 | B2 |
6626061 | Sakamoto et al. | Sep 2003 | B2 |
6658963 | Yaddehige | Dec 2003 | B2 |
6718845 | Menzies | Apr 2004 | B2 |
6745642 | Kumamoto et al. | Jun 2004 | B2 |
6758114 | Sundaresan et al. | Jul 2004 | B2 |
6802113 | Staker | Oct 2004 | B2 |
6834564 | Huesges et al. | Dec 2004 | B2 |
6857336 | Staker | Feb 2005 | B2 |
6860170 | DeForest | Mar 2005 | B2 |
20010011487 | Kojima et al. | Aug 2001 | A1 |
20010015111 | Rixon et al. | Aug 2001 | A1 |
20010022113 | Kojima et al. | Sep 2001 | A1 |
20010029805 | Wehner et al. | Oct 2001 | A1 |
20020005080 | Reimann et al. | Jan 2002 | A1 |
20020157495 | Goto et al. | Oct 2002 | A1 |
20030226419 | Yokochi et al. | Dec 2003 | A1 |
20040041558 | Hasegawa et al. | Mar 2004 | A1 |
20040065167 | Kim | Apr 2004 | A1 |
20040149069 | Caba et al. | Aug 2004 | A1 |
20040149070 | Solta | Aug 2004 | A1 |
20040237700 | Wurn | Dec 2004 | A1 |
20050034292 | Staker | Feb 2005 | A1 |
20050034555 | Staker | Feb 2005 | A1 |
20050046273 | Jung et al. | Mar 2005 | A1 |
20050097983 | Mannle et al. | May 2005 | A1 |
20050145058 | Kohlen et al. | Jul 2005 | A1 |
20050155448 | Lochle et al. | Jul 2005 | A1 |
20050160867 | Mannle | Jul 2005 | A1 |
20050172753 | Fujiwara | Aug 2005 | A1 |
20070000347 | Keown et al. | Jan 2007 | A1 |
Number | Date | Country |
---|---|---|
19521821 | Dec 1996 | DE |
1126353 | Aug 2001 | EP |
1357452 | Oct 2003 | EP |
2349447 | Nov 2000 | GB |
2004007929 | Jan 2004 | WO |
Number | Date | Country | |
---|---|---|---|
20070137395 A1 | Jun 2007 | US |
Number | Date | Country | |
---|---|---|---|
60731880 | Oct 2005 | US |