GB2244324A - A foot pedal arrangement, eg. for vehicles - Google Patents

Abstract

A foot pedal (14) e.g. for operating hydraulic mechanisms in vehicles is connected to its operating rod (24) by means of a rubber or rubber-like grommet (42) which is fitted in an elongate aperture (38) in the pedal and which retains the operating rod. The flexibility of the grommet allows for the differences in relative orientation which take place throughout the range of movement of the pedal. <IMAGE>

Description

A FOOT PEDAL ARRANGEMENT This invention relates to a foot pedal arrangement for use in a motor vehicle. The invention is particularly concerned with an arrangement where the foot pedal operates a hydraulic mechanism, but is not restricted to such an application.

Where a hydraulic mechanism is to be operated by a pivotally mounted foot pedal, a variation in relative orientation has to be catered for because the operating member of the hydraulic mechanism will move along a linear path, whereas the pedal itself will move along an arcuate path. US Patent 4 708 028 describes an arrangement where the variations in orientation are taken care of by two part-spherical members which can move relative to one another without straining either member and whilst transmitting force. However in this arrangement there is some play between the two parts, and this has two disadvantages. Firstly there is the possibility of some backlash in the mechanism, ie under certain conditions the driver may push the pedal with his foot and there will be a short distance of pedal travel before contact is made with the operating member for the hydraulic mechanism.This is a disadvantage in terms of driver "feel". Secondly, because one part is a loose fit relative to the other there is the possibility of some rattling between the two components.

According to the present invention, there is provided an foot pedal arrangement comprising a foot pedal mounted for arcuate movement about a pivot axis and an operating member mounted for linear movement in the same plane as the arcuate movement, the pedal being provided with an elongated aperture, the major dimension of the aperture extending in the plane of the arcuate movement, and a flexible grommet fitted in the aperture, the grommet having a hole therethrough such that the hole in the grommet is adapted to receive an end of the operating member, the operating member being adapted to enter the hole in one direction and then to be prevented from coming out of the hole in the opposite direction.

The grommet is preferably of a rubber or rubber-like material, and the operating member may have a fir-tree formation on it which will allow the operating member to be pushed through the hole in one direction but will prevent the operating member from being pulled out of the hole in the opposite direction.

The grommet may take the form of a tubular sleeve with a radially extending skirt extending around one end of the sleeve. The sleeve preferably receives and grips the operating member, and the sleeve may also have external projections which retain the grommet in the pedal aperture.

The operating member may be provided with a radiallyextended abutment which will make contact with the radial skirt of the grommet. The underside of the skirt may have projections which locate the tubular part of the grommet centrally in the pedal aperture.

The pedal itself preferably has a contoured area surrounding the elongated aperture, the contoured surface being designed so that it is perpendicular to the plane of the arcuate movement of the pedal. The size of the contoured area is preferably substantially equal to that of the skirt of the grommet.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of a foot pedal installation in a motor vehicle; Figure 2 shows a vertical section through the pedal of Figure 1; Figure 3 shows a horizontal section through the pedal of Figure 1; and Figure 4 is an exploded, partly cut away view showing the top end of the pedal and the grommet separated from one another.

Figure 1 shows the front bulkhead 10 of a motor vehicle and part of the floor pan at 12. A foot pedal 14 has a pad 16 at the bottom end on which the driver's foot acts, and is pivoted on a pivot pin 18 at its upper end. The pin 18 is supported in a bracket 20 secured rigidly to the bulkhead 10. There will normally be a return spring (not shown) associated with the pivot 18 which will act on the pedal in opposition to pressure from the driver's foot.

In Figure 1, the pedal 14 is a brake pedal which operates a hydraulic brake servo 22 through an operating rod 24. In operating the servo, the rod 24 moves along a linear path indicated by the double headed arrow 26. The brake servo has a hydraulic fluid reservoir at 28. A flexible gaiter 30 surrounds the rod 24 and seals an opening 32 in the bulkhead 10.

The manner in which the rod 24 is connected to the pedal 14 will be described with reference to Figures 2, 3 and 4.

Looking first of all at Figure 4, the pedal can be seen to be of channel-section with holes 34 in the side walls by means of which the pedal is supported on the pivot pin 18.

In the wall 36 of the pedal there is an elongated aperture 38 surrounded by a contoured surface 40. A separate rubber grommet 42 fits into this aperture. The grommet has a tubular sleeve 44 with a radially extending skirt 46 at one end of the sleeve. The periphery of the skirt 46 corresponds to the peripheral shape of the contoured area 40. The sleeve 44 will pass through the aperture 38, and has two opposed radial projections 48 and 50 which are positioned so as to retain the grommet in the aperture. On the underside of the skirt 46 there are two further locating projections 52 and 54 which locate the sleeve 44 centrally in the aperture 38.

Figures 2 and 3 show the grommet 42 fitted in the aperture.

Figure 3 shows how the projections 48 and 50 retain the grommet in the aperture, and Figure 2 shows how the locating projections 52 and 54 provide a locating function.

Once the grommet has been inserted in the aperture in the pedal, the operating rod 24, with a large diameter washer or abutment plate 56 fitted as shown can be pushed through the sleeve 44. The end of the rod 24 has a fir-tree formation 58 on that part of its circumference which will lie within the sleeve 44, and this will allow the rod to be pushed in through the sleeve, but prevent it being pulled out. Once the abutment plate 56 is in contact with the skirt 46, movement of the pedal will produce a corresponding movement of the rod 24, without any backlash.

The contoured area 40 is shown most clearly in Figures 2 and 4 and it will be seen that this comprises roughly two semicircular surfaces both of which lie in a plane parallel to the axis of the pivot 18 and perpendicular to the plane in which the pedal will move. This will accommodate the difference in relative angular position between the rod 24 and the pedal 14 when the pedal is actuated. The use of an elongate aperture and the inherent compliance of the grommet will also allow the rod 24 to be moved to the necessary extent along the elongated aperture during actuation of the pedal.

The use of a rubber or rubber-like grommet between the operating rod and the pedal ensures that the two parts are held firmly together in a manner which will prevent any lost motion between the parts and which will therefore also prevent any rattling. Assembly of the arrangement is particularly easy.

Once the rod 24 has been inserted through the grommet, the locking projections 48 and 50 are prevented from moving inwardly, and therefore the grommet is locked in place in the pedal aperture.

Claims (9)

1. A foot pedal arrangement comprising a foot pedal mounted for arcuate movement about a pivot axis and an operating member mounted for linear movement in the same plane as the arcuate movement, the pedal being provided with an elongated aperture, the major dimension of the aperture extending in the plane of the arcuate movement, and a flexible grommet fitted in the aperture, the grommet having a hole therethrough such that the hole in the grommet is adapted to receive an end of the operating member, the operating member being adapted to enter the hole in one direction and then to be prevented from coming out of the hole in the opposite direction.

2. A foot pedal arrangement as claimed in Claim 1, wherein the grommet is of a rubber or rubber-like material with a hole through it, and the operating member has a fir-tree formation on it which will allow the operating member to be pushed through the hole in one direction but will prevent the operating member from being pulled out of the hole in the opposite direction.

3. A foot pedal arrangement as claimed in Claim 1 or Claim 2, wherein the grommet takes the form of a tubular sleeve with a radially extending skirt extending around one end of the sleeve.

4. A foot pedal arrangement as claimed in Claim 3, wherein the sleeve receives and grips the operating member, and also has external projections which retain the grommet in the pedal aperture.

5. A foot pedal arrangement as claimed in any preceding claim, wherein the operating member is provided with a radially-extended abutment which will make contact with the grommet.

6. A foot pedal arrangement as claimed in Claim 3 or Claim 4, wherein the underside of the skirt has projections which locate the tubular part of the grommet centrally in the pedal aperture.

7. A foot pedal arrangement as claimed in any preceding claim, wherein the pedal itself has a contoured area surrounding the elongated aperture, the contoured surface being designed so that it is perpendicular to the plane of the arcuate movement of the pedal.

8. A foot pedal arrangement as claimed in Claim 7, wherein the size of the contoured area is substantially equal to that of the skirt of the grommet.

9. A foot pedal arrangement substantially as herein described with reference to and as shown in the accompanying drawings.