COLLAPSIBLE PEDAL BOX

Abstract: A collapsible pedal box for an automobile is designed to collapse in the case of a frontal impact of the automobile, to reduce the risk of trapping the driver's feet. One or more pedals (13) are supported on a pivot shaft which is supported at its ends by pivot shaft supports (15, 17) locked with respect to the side walls (1, 3) of the pedal box that they are prevented from moving outwardly along an axis of the pivot shaft. Relative movement between the pedal box and another structural member within the driver's compartment in the case of a front-end impact causes first the unlocking and then the movement apart of the pivot shaft supports (15, 17) and release of the pivot shaft and pedal assembly.

Description: TITLE Collapsible Pedal Box DESCRIPTION Field of the Invention This invention relates to pedal boxes for automobiles, and to structures which are designed to collapse in the event of a front-end vehicle collision. Background Art The improved design of safety shell structures around the driving compartment of a motor vehicle, and the improvements in the shock absorbing characteristics of engine compartment, have meant that it is now much less likely that the driver of a vehicle in a front-end collision will be killed outright. With that increase in vehicle safety comes another concern, which is that the driver whose lifeitøs been spared by good vehicle design should not become injured or trapped in t e vehicle by the pedal box structure around the driver's feet. Brake and clutch pedal boxes have been proposed which collapse on application of an excessive load such as that applied by the forward momentum of a driver when the vehicle is in a front-end collision. A collapse of the pedal box in such a situation permits the pedals of the vehicle to move forward and away from the driver's feet, providing important extra legroom to reduce the risk of the driver's feet becoming trapped in the accident. Even a few centimetres of extra legroom in such circumstances can be a significant safety advantage. Various prior proposals for collapsible pedal box design have contemplated making the pedal box collapse dependent on the impact itself. It is however important to reduce as much as possible the extent to which the reaction pressure of the driver's foot on the pedal or pedals is necessary to initiate pedal box collapse. Similarly it is important to reduce as much as possible the reliance on any other member which might come into contact with the driver, such as a steering column member, as a source of the reaction pressure. A collapsible pedal box has previously been described in EP 0827874. The pivot shaft is journalled between pivot shaft supports which are permanently mounted on the inner surface of the opposing side walls. In the event of a frontal impact, a member in the passenger compartment collides with the front of the two side walls forcing them apart while on the engine side the side plates are brought together. Accordingly, the two pivot shaft supports are forced apart to release the pivot shaft. However, since the two side walls twist in opposite directions during the impact, the two pivot shafts are unable to move mutually apart along the axis of the pivot shaft and so there is a greater likelihood that the pivot shaft will still be retained by one of the supports after impact. Summary of the Invention The invention provides a pedal box for pivotally supporting one^r more control pedals of an automobile, wherein a pivot shaft for the pedal or pedals is journalled at its ends in discrete pivot shaft end supports which are physically locked with respect to side walls of the pedal box such that they are prevented from moving outwardly along an axis of the pivot shaft, characterized in that relative movement between the pedal box and another member of the automobile in the event of a frontal impact unlocks the pivot shaft end supports with respect to the side walls so that they can move mutually apart along the axis of the pivot shaft thereby causing release of the pivot shaft from the pivot shaft end supports so as to initiate collapse of the one or more pedals. By relying on the relative movement between the pedal box and the other member of the automobile to effect the release of the ends of the pivot shaft mounting the control pedal or pedals, true synchronization of the collapsing driver's compartment and pedal collapse can be reliably obtained in the event of a frontal impact of the vehicle. Preferably the pivot shaft end supports are spring-biased to move them mutually apart after they have been unlocked with respect to side walls of the pedal box, thus releasing the ends of the pivot shaft from the shaft end supports. Alternatively continued relative movement between the pedal box and the other member in the driver's compartment may be effective to bias apart the unlocked pivot shaft end supports by cam action. A further alternative is for the unlocked pivot shaft end supports to be moved mutually apart, after unlocking, by a combination of spring- bias and cam action forces. In one embodiment of the invention, the unlocking of the pivot shaft end supports is achieved by rotary movement of the pivot shaft end supports imparted by contact between the relatively movable member in the driver's compartment and lever portions of the pivot shaft end supports. Where a cam action is used to bias the pivot shaft end supports apart, that cam action is preferably a cam action between cooperating surfaces of the pivot shaft end supports and the relatively movable element in the drivers compartment, or between the pivot shaft end supports and cooperating surfaces of the pedal box. The latter cam action may be achieved, for example, by rotary movement of the pivot shaft end supports whicl gpn rotation bear against the pedal box. Such rotary movement is imparted by contact between the relatively movable member in the driver's compartment and lever portions of the pivot shaft end supports, and is preferably a continuation of the rotary movement which unlocks the pivot shaft end supports from the side walls of the pedal box. A second embodiment of a pedal box according to the invention further comprises a latch member and a release spring, wherein, in use, the latch member is locked to the side walls of the pedal box in a first position and prevents the pivot shaft end supports from moving mutually apart whereas the release spring is in a compressed state biasing the pivot shaft end supports mutually apart such that in the event of a frontal impact the latch member is unlocked from the side walls and moves to a second position thereby releasing the pivot shaft end supports and the release spring relaxes to force the pivot shaft end supports mutually apart along the axis of the pivot shaft through holes in the side walls of the pedal box. Preferably, in addition to biasing the pivot shaft end supports apart, the release spring also biases the latch member from the first position to the second position. Preferably, the latch member is locked in its first position to the side walls of the pedal box by one or more outwardly extending detents which engage with corresponding recesses provided in the side walls of the pedal box and in the event of a frontal impact, the detents shear permitting the latch member to move to the second position. The Drawings Figure 1 is a perspective view of a pedal box according to a first embodiment of the invention; Figure 2 is a perspective view of the far side wall of the pedal box as viewed in Figure 1 ; Figure 3 is a perspective view of the pair of pivot shaft supports of Figure 1 , viewed from the same angle 7 as in Figure 1 ; Figure 4 is a side elevation of one of the pivot shaft supports of Fjgjire 3, viewed in the direction of arrow A; Figure 5 is a side elevation of the pedal box of Figures 1 to 4 in position in an automobile, illustrating its cooperation with an element of a relatively movable member in the driver's compartment; Figure 6 is a section through an alternative pivot shaft supports for use in a pedal box according to the invention; Figure 7 is a plan view of a pedal box according a second embodiment of the invention; Figure 8 is a perspective view of the pedal box of Figure 7; Figure 9 is a perspective view of the latch member of Figure 7 and 8; Figure 10 is a plan view of the pedal box of Figures 7 and 8 in position in an automobile; Figure 11 is a perspective view of Figure 10; Figure 12 is a plan view of the pedal box of Figures 10 and 11 , illustrating what happens after the automobile has been involved in a front-end impact; Figure 13 is a perspective view of the pedal box of Figure 12; Figure 14 is a perspective view of a pedal box according to a third embodiment of the invention, illustrating in particular how the pivot shaft and pivot shaft supports are initially installed into the pedal box; and Figure 15 is an exploded perspective view of the pedal box of Figure 14 in which, for ease of reference, the pivot shaft support is removed from the side wall of the pedal box even though in the locked position illustrated, the locking wings of the pivot shaft supports are actually locked against the inside surface of the side walls of the pedal box preventing such removal. Figure 1 shows a pedal box according to the invention comprising two side walls 1 ,3 joined together in a rigid box formation by a front end top wall 5 and a rear wall 7. In use the pedal box is^bolted to a rigid bulwark 9 separating the engine compartment of an automobile from the passenger compartment. The bulwark 9 is shown schematically in section only in Figure 5, and bolt-mounting holesij 1 are shown in Figures 1 and 2. Mounted between the side walls 1 and 3 of the pedal box is a control pedal 13 of the automobile. The pedal 13 may be a brake pedal, a clutch pedal or an accelerator pedal, or a group of two or more such pedals mounted on a single pivot shaft. The pivot shaft (not shown) is journalled at its opposite ends in a pair of pivot shaft supports 15,17, and is pivotally suspended beneath the pedal box. A return spring (not shown) is in use anchored at one end to a stub shaft 19 on the pedal 13, and the pedal in use is capable of movement in an arc as indicated by the double- headed arrow B. The pivot shaft supports 15,17 pass through the side walls 1 ,3 of the pedal box from the outside, and present two journals one for each end of the pivot shaft of the pedal 13. The pivot shaft is shorter than the spacing between the side walls 1 ,3 so that if the pivot shaft supports 15,17 were withdrawn back through the side walls 1 ,3 the pivot shaft would fall away from the pedal box. In normal use, however, the shaft supports 15,17 are locked to the side walls 1 ,3 because the holes 21 through which they pass are butterfly-shaped as shown in Figure 2, with a circular inner locating portion 21a and two diametrically opposed release portions 21b of larger diameter. The shaft supports 15,17 have cylindrical journal housing portions 23a of the same diameter as the locating portions 21a, and diametrically opposed locking wings 23b which pass through the release portions 21b and then lock against the inside faces of the side walls 1 ,3 when the shaft supports 15,17 are rotated to the positions shown in Figures 1 and 5. It should be understood that the angular width "d" (Figure 2) of the release portions 21b is greater than the angular length "e" (Figure 3) of the locking wings 23b, so that some free angular rotation of the shaft supports 15,17 is permitted while the locking wings 23b lie within the boundaries of the release portions 21b. Figure 4 illustrates io-w one such shaft support 17 passes through the side wall 3 of the pedal box (shown in chain-dotted line) and is locked thereto by the locking wings 23b. The depth "f of the shaft support 17 on the inside of the pedaJsbox provides the journal support for the end of the pivot shaft. Each of the shaft supports 15,17 has a lever portion 25,27 which in use extends upwardly past the pedal box beyond the top wall 5 of the pedal box, and beyond a pair of straight outwardly-turned flanges 1a, 3a of the side walls 1 ,3 of the pedal box. The combination of the flanges 1a, 3a and the top wall 5 of the pedal box create a guide surface which sweeps along a relatively rigid member in the driver's compartment when, in the case of a severe frontal impact of the automobile, the pedal box is pushed into the driver's compartment. The relatively rigid member in the driver's compartment may, for example, be a bracket 30 (Figure 5) supporting a steering column, such that the flanges 1a, 3a are swept by that bracket when a front- end impact pushes the pedal box rearwardly of the automobile. Initial relative movement between the pedal box and the bracket 30 causes the bracket 30 to move in the direction of the arrow C of Figure 5, bearing against the lever portions 25,27 and rotating the shaft supports 15,17 in the direction of the arrow D. Initial rotation, corresponding to the above initial and partial relative movement, causes the shaft supports 15,17 to become unlocked from the pedal box side walls so that they are capable of moving mutually apart to release the pivot shaft ends of the pedal 13. Continued rotation, caused by continued and progressive relative movement, causes identical angled cam surfaces 29 of the two shaft supports 15,17 to ride up the out-turned flanges 1a, 3a of the pedal box side walls 1 ,3 to cam the shaft supports outwardly. The ends of the pivot shaft of the pedal 13 are therefore released from the shaft supports 15,17 and the pedal falls away to minimize the risk of trapping the driver's feet as a result of the front-end impact of the vehicle. Figure 6 shows a modification of the pivot shaft supports of Figures 1 to 5. Each is provided with an annular recess 60 centred around the pivotal axis of the pivot shaft support. In that annular recess 60 is biasing means such as a stack of Belleville washers 62 (as illustrated) or a compression coil spring (not illustrated) which biases the pivot shaft support away from the side wall of the pedal box.j-ξOther items are numbered as in Figure 4. Identical spring means on both of the pivot shaft supports 15,17 means that they are biased apart. They move apart, releasing the pivot shaft for the control pedal, as soon as rotation of the pivot shaft supports effects release of the locking wings 23b from the butterfly-shaped holes 21. Figures 7 to 13 show a collapsible pedal box according to a second embodiment of the present invention. Again the pedal box is formed from two side walls 1 ,3 which are bolted onto the rigid bulwark which separates the engine compartment of the automobile from the passenger compartment by the bolt-mounting holes 11. A control pedal 13 of the vehicle is pivotally mounted on a pivot shaft 50 which is journalled at its ends by pivot shaft supports 52. Each pivot shaft support 52 has a cylindrical journal portion 52a, a locking wing 54 and a land 56 (see Figure 8). The outer profile of each pivot shaft support 52 corresponds to that of a hole 4 provided in each of the side walls 1 ,3 for insertion and removal. Additionally, a latch member 60 (see Figure 9) is provided which comprises two side plates 66 with a striking plate 62 and a channelled cross member 64 therebetween. An arcuate recess 68 is formed from the base of each of the side plates 66 which, in use, receives the cylindrical journal portion 52a of the corresponding pivot shaft support 52. Two inwardly projecting spring retainers 70 are mounted on the inner surface of each side plate 66. Furthermore, an upwardly and outwardly extending detent 72 is formed from each side plate 66 which, in use, engages with a locking recess 73 in the corresponding side wall 1 ,3 to retain the pedal box in its normal operation condition. The pedal box further includes a release spring 74 having two forked ends 76. As illustrated in Figures 7 and 8, the control pedal 12 is mounted on its pivot shaft 50 and the pivot shaft supports 52 are inserted, locking wing side first, through the holes 4 on either side wall 1 ,3 to support and journal the pivot shaft 50. The release spring 74 is then located between the spring retainers 70 of the side plates 66 and the channel 65 of theϊ-cross member 64. Although the forked ends 76 of the release spring 74 initially protrude through the arcuate recesses 68 in the side plates 66 as shown in Figures 7 and 8, as the entire latch member 60 is moved^ownwards from the position shown to secure it in place, the forked ends 76 are forced inwards into the cavity defined between the side plates 66 and the channelled cross member 64. Further downward movement of the latch member 60 eventually causes the detents 72 of the side plates 66 to snap-fit into engagement with the corresponding locking recesses 73 of the side walls 1 ,3 thereby locking the pedal box in its normal operating position as shown in Figures 10 and 11. Due to the deformation undergone by the release spring 74, its forked ends 76 which are in abutment with the locking wings 54 of the pivot shaft supports 52 tend to bias the supports 52 outwardly along the axis of the pivot shaft 50. However, in the normal operating position, this outwardly bias is resisted by the side plates 66 of the latch member 50. The cylindrical journal portion 52a of each pivot shaft support 52 is accommodated within the arcuate recess 68 at the base of the side plates 66 and so the locking wings 54 are retained in position between the forked ends 76 of the release spring 74 and the side plates 66 of the latch member 60. The deformation of the release spring 74 also biases the latch member 60 upwards through its reaction on the channelled cross member 64. However, in the normal operating position, this upwards biasing of the latch member 60 is restrained by the snap-fit engagement between the detents 72 and the corresponding locking recesses 73. In the event of a front-end collision of the automobile, the pedal box is pushed rearwardly into the passenger compartment in the same manner as illustrated in Figure 5. However, in this instance, the bracket 30 strikes the striking plate 62 of the latch member 60 rather than bearing against the lever portions 25,27 of the previous embodiment. As illustrated in Figures 12 and 13, the impact of the bracket 30 against the striking plate 62 causes the detents 72 to shear which in turn permits the release spring 74 to force the latch member 60 upwards as indicated by arrow E. As the latch member 60 moves upwards, the side plates 66 are noypnger disposed between the locking wings 54 and the respective side walls 1 ,3. Accordingly, the release spring 74 is permitted to expand outwards and in doing so hurls the pivot shaft supports 52 outwards along the axis of the pivot shaft 50 as shown by arrows F and through the holes 4 in the side walls 1 ,3 of the pedal box and hence the pivot shaft 50 and control pedal 13 fall to the floor of the automobile. The presently preferred embodiment of the present invention, which combines some of the features discussed in relation to the previously described embodiments, is illustrated in Figures 14 and 15. The pedal box comprises two side walls 1 ,3 a pivot shaft 50 on which a control pedal 13 is mounted, two spring-biased pivot shaft supports 80 and a latch 90. Figure 14 shows in particular how the pivot shaft 50 and pivot shaft supports 80 are initially installed into the pedal box. Either end of the pivot shaft 50 is inserted into butterfly-shaped latch holes 92 of the latch 90 which in turn is introduced between the two side walls 2,3 of the pedal box. The latch holes 92 and the pivot shaft 50 are then held in the position shown so that they are concentric with opposing butterfly- shaped holes 86 provided in the side walls 2,3. A non-rotatable plate spring 84 (only one of which is shown) is then placed over each butterfly-shaped hole 86 in the side walls 1,3 on the outer surfaces thereof. The spring 84 has a through-hole which corresponds to the butterfly-shaped hole 86. Then, the locking wings 82 of the pivot shaft supports 80 (only one of which is shown) are inserted through the through-hole of the springs 84, the butterfly-shaped holes 86 in the side walls 1 ,3 and into engagement with the correspondingly shaped butterfly-shaped latch holes 92 of the latch 90. Accordingly, rotation of the latch 90 causes simultaneous rotation of the pivot shaft supports 80 due to the engagement between the locking wings 82 and the butterfly-shaped latch holes 92. Once the pivot shaft 50 is held between the pivot shaft supports 80, the latch 90 can be rotated anticlockwise to lock the locking wings 82 of the pivot shaft supports 80 against the inner surfaces of the side walls ,3, thereby preventing the pivot shaft supports 80 from moving mutually apart along the pivot shaft axis. - Although Figure 15 represents the pedal box in the locked position, for ease of reference, the pivot shaft support 80 has been removed from the side wall 1 of the pedal box to show specifically the rotary position of the locking wings 82 in the locked condition even though in the locked condition, the locking wings 82 are actually locked against the inside surface of the side walls 1,3 of the pedal box preventing such removal. Once the latch has been rotated to the position shown, it is secured to each of the side walls 1 ,3 by rivets 94 to prevent accidental rotation. In the event of a front-end vehicle collision, the pedal box is pushed rearwardly into the passenger compartment in the same manner as illustrated in Figure 5. The bracket 30 on this occasion strikes the latch 90 with sufficient force to shear the rivets 94 and rotate the latch 90 clockwise which causes simultaneous clockwise rotation of the pivot shaft supports 80 to the position illustrated in Figure 14. Here, the locking wings 82 are unlocked from the side walls 1,3 and due to the outward bias imposed by the springs 84, the pivot shaft supports 80 are forced mutually apart along the axis of the pivot shaft allowing the pivot shaft 50 and latch 90 to drop to the floor of the passenger compartment.

Claims: CLAIMS 1. A pedal box for pivotally supporting one or more control pedals (13) of an automobile, wherein a pivot shaft (50) for the pedal or pedals is journalled at its ends in discrete pivot shaft end supports (15,17;52;80) which are physically locked with respect to side walls (1 ,3) of the pedal box such that they are prevented from moving outwardly along an axis of the pivot shaft, characterized in that relative movement between the pedal box and another member of the automobile (30) in the event of a frontal impact unlocks the pivot shaft end supports (15,17;52;80) with respect to the side walls (1 ,3) so that they can move mutually apart along the axis of the pivot shaft thereby causing release of the pivot shaft (50) from the pivot shaft end supports (15,17^2;80) so as to initiate collapse of the one or more pedals (13). 2. A pedal box according to claim 1 , wherein the - pivot shaft end supports (15,17;52;80) are spring-biased to move them mutually apart or to aid their movement mutually apart after they have been unlocked with respect to the side walls (1 ,3) of the pedal box. 3. A pedal box according to claim 1 or claim 2, wherein the pivot shaft end supports (15,17;80) pass through non-circular apertures (21 ;86) in the side walls (1 ,3) and are then partially rotated to lock them with respect to the side walls (1 ,3) and the relative movement between the pedal box and said another member (30) causes rotary movement of the pivot shaft end supports (15,17;80) to a rotary condition in which they are unlocked from the side walls (1 ,3) of the pedal box. 4. A pedal box according to claim 3, wherein the unlocking of the pivot shaft end supports (15,17;80) from the side walls (1 ,3) of the pedal box is achieved by rotary movement of the pivot shaft end supports (15,17;80) imparted by contact between said other member (30) and lever portions (25,27;90) on the pivot shaft end supports (15, 17;80). 5. A pedal box according to any preceding claim, wherein the pivot shaft end supports (15,17) are biased apart by a cam action imparted by the relative movement between the pedal box and said other member (30). 6. A pedal box according to claim 5 when appended to claim 4, wherein after contact between said other member and the lever portions (25,27) of the pivot shaft end supports (15,17) has caused rotary movement of the pivot shaft end supports (15,17) to unlock them from the side walls (1 ,3) of the pedal box, continued relative movement is effective to bias apart the pivot shaft end supports (15,17) by cam action. 7. A pedal box according to claim 6, wherein the cam action is reaction between an inclined surface (29) of each of the lever portions (25,27) of the pivot shaft end supports (15,17) and reaction surfaces (1a,3a) of the pedal box side valls (1 ,3). 8. A pedal box according to claim 2 further comprising a latch member (60;90) and a release spring (74;84), wherein, in use, the latch member (60;90) is locked to the side walls (1 ,3) of the pedal box in a first position and prevents the pivot shaft end supports (52;80) from moving mutually apart whereas the release spring (74;84) is in a compressed state tending to bias the pivot shaft end supports (52;80) mutually apart such that in the event of a frontal impact the latch member (60;90) is unlocked from the side walls (1 ,3) and moves to a second position thereby releasing the pivot shaft end supports (52;80) and the release spring (74;84) relaxes to force the pivot shaft end supports (52;80) mutually apart along the axis of the pivot shaft (50) through holes (4;86) in the side walls (1 ,3) of the pedal box. 9. A pedal box according to claim 8, wherein the release spring (74) in addition to biasing the pivot shaft end supports (52) apart, also biases the latch member (60) from the first position to the second position. 10. A pedal box according to claim 8 or claim 9, wherein the latch member (60;90) includes one or more fixings (72;94) which engage with the side walls (1 ,3) of the pedal box to lock the latch member (60;90) in its first position and in the event of a frontal impact, the fixings (72;94) fail permitting the latch member (60,90) to move to the second position.

Inventors: BYRON DONALD JOHN, SAUVENEE PIERRE, WILLIAMS CHRISTOPHER GARTH, BYRON, DONALD, JOHN, SAUVENEE, PIERRE, WILLIAMS, CHRISTOPHER, GARTH
Applicants: BYRON DONALD JOHN, DURA AUTOMOTIVE LTD, SAUVENEE PIERRE, WILLIAMS CHRISTOPHER GARTH, BYRON, DONALD, JOHN, DURA AUTOMOTIVE LIMITED, SAUVENEE, PIERRE, WILLIAMS, CHRISTOPHER, GARTH
Application year: 2001
Main classification: B60R21
IPC codes: B60R21, B60T7, G05G1