GB2301876A

GB2301876A - Vehicle pedal removable moulded interface arrangement

Info

Publication number: GB2301876A
Application number: GB9511466A
Authority: GB
Inventors: Ronald Ian Cotterill; Joseph Pell; Kenneth Dunning
Original assignee: Ferodo Ltd
Current assignee: Federal Mogul Friction Products Ltd
Priority date: 1995-06-07
Filing date: 1995-06-07
Publication date: 1996-12-18
Anticipated expiration: 2015-06-07
Also published as: GB2301876B; GB9511466D0

Abstract

A method of releasably securing an actuable device, such as a force transducer, to a vehicle control pedal 10 comprises releasably securing to the pedal an interface arrangement 20, moulded to conform to a force application surface 14 of the pedal, and securing the device to the interface arrangement. A method of forming such an interface consists of placing uncured polyester resin 25 in an open-topped rectangular container 21, inverting the container over the pedal and depressing it onto the force application surface 14 until it abuts and the resin surrounds forwardly facing surfaces of the pedal, curing the resin to define an interface body 27 comprising container and resin with a flat support surface 26, and retaining the body with respect to the pedal by securing to it a container lid 31 disposed adjacent the rearward surface of the pedal and carrying a bias spring 35 extending to the other surface 15 of the pedal to bias the body towards the pedal surface. The container base provides a support surface 26 for a low profile force transducer 17 whilst permitting near-normal pedal operation.

Description

Vehicle pedal removable moulded interface arranaement This invention relates to releasably securing an actuable device to a vehicle control pedal and in particular relates to the provision of a releasable interface arrangement by which force applied to the actuable device can be transmitted into a normal force application region of the pedal or vice versa.

The invention is particularly, but not exclusively, concerned with automobile brake control pedals and monitoring forces applied to the pedal and/or pedal displacements resulting therefrom in phases of its operation.

There exists in automobile engineering a requirement to determine what forces are required throughout the operation of control pedals, for example, to operate the brakes of a vehicle.

Typically operation of a brake control pedal involves depressing the pedal through a significant distance against little resistance to motion, followed by a significant increase in resistance as the brakes are fully applied. The initial low resistance phase may be prolonged by the use of servo assistance.

In developing braking arrangements for vehicles manufactures wish to monitor not only what forces have to be applied to the control pedal when the brakes are fully applied but also the forces required in initial travel of the pedal in order to define an objective 'comfort' or 'ease of use' factor for the design of the braking system as a whole.It will be appreciated that such 'comfort' factor associated with pedal operation is, as far as the operative is concerned, not only partly subjective but also subconscious; that is, in order to provide an objective measurement of such factor to correlate with subjective information from the operative, it is necessary to monitor such initial pedal depression forces during normal operation of the vehicle, such monitoring is required not to alter the normal relationship between operative and pedal to any greater significance than experienced through variations between pedal layouts in samples of the same vehicle model, and full and unimpeded operation of the brakes has to be retained without compromising safety.

It has been proposed to measure various pedal forces involved in braking by securing a pressure transducer to the pressure application region of a brake control pedal such that the pedal is operated by way of the transducer and the forces involved can be measured by change in electrical signals related to changes in transducer parameters with applied force. However, such transducers as hitherto available have all had significant thickness, such that their interposition between pedal and operative's foot significantly affects the pedal operation and/or functions only over a restricted range of applied forces before being susceptible to damage, so that a sensitive transducer having an operating range responsive to low force initial pedal travel may be damaged if and when significant force is applied at the conclusion of the braking operation.

It is an object of the present invention to provide a method of releasably securing an actuable device to a vehicle control pedal. It is also an object of the present invention to provide a removable vehicle pedal interface arrangement of simple construction to provide a mechanical interface between a force transmitting surface region of a vehicle pedal and an actuable device. It is also an object of the present invention to provide a method of making a removable interface arrangement.

According to a first aspect of the present invention a method of releasably securing an operating device to a vehicle control pedal, having an operating arm and a force application region including a force application surface facing forwardly towards an operative, to effect, by actuation of the device, operation of the control pedal by way of said force application surface, comprises, in any order, securing about the force application region a removable interface arrangement moulded to conform to said force application surface and securing the actuable device to the interface arrangement.

According to a second aspect of the present invention a removable interface arrangement, for a vehicle control pedal having an operating arm and a force application region including a force application surface facing forwardly towards an operative, comprises a force transmitting body moulded to conform with, and surrounding, the forwardly facing surface of said force application region and including a support surface formed therewith overlying said force application surface, said body being removable from the force application region in said forwardly facing direction, and a retaining part releasably securable to the body and adapted to bear against a rearwardly facing surface of the pedal to hold said body in abutment with the force application surface for transmission of forces thereto from the support surface.

According to a third aspect of the present invention a method of making a removable interface arrangement for a vehicle control pedal having an operating arm and a force application region including a force application surface facing forwardly towards an operative, comprises disposing within an open-topped container large enough to surround the force application region a plastic material solidifiable into a rigid pressure transmissible form, disposing the container inverted over the force application region from said forward direction and depressing it towards the region such that the floor of the container is proximate to the force application surface and the plastic material is distributed about the force application region, aligning the floor of the container with a desired direction relative to the force application surface such that the floor of the container defines a support surface, effecting solidification of the material in conformity with the force application region but not a rearwardly facing surface thereof to define a force transmitting interface body, and mechanically and releasably securing to said body a retaining part, adapted to bear on a rearwardly facing surface of the pedal, to hold said solidified material in abutment with the force application surface for transmission of forces thereto from the support surface.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure l(a) and l(b) are front and side views respectively of a pressed steel automobile brake control pedal having a pivotally mounted operating arm portion and a force application region, Figures l(c) and 1(d) are sectional and cross-sectional elevations through the force application region of Figure l(a) in the direction c-c and d-d respectively showing details of the structural features thereof, Figure 2 is a perspective view of the pedal and interface arrangement secured thereto illustrating the support of a low profile force transducer overlying the force application surface of the pedal, coupling of other devices actuable with a pedal displacement, Figure 3 is a sectional elevation through a portion of a brake control pedal, similar to Figure l(c) but showing disposed with respect to the force application region an interface arrangement in accordance with the present invention, and Figure 4 is a sectional elevation similar to Figure 3 but through a different form of pedal construction.

Referring to Figures l(a) to 1(d) a vehicle brake pedal 10 is formed from sheet steel pressed into a channel form of generally U-shaped cross-section, as best seen in Figure l(d), and comprises an operating arm 11 pivotable at one end about spindle 12 and at the other end formed into an integral pressure application region 13 which presents a generally convex pressure application surface 14 in a forward direction towards an operative.

It will be appreciated from Figure 1(d) that in forming the pedal and its pressure application region by pressing from sheet, the channel section has slightly divergent walls such that the pressure application region may be considered as generally forwardly facing, not only in respect of the force application surface 14 but also in respect of the surfaces 14' and 14'' of the channel walls adjacent thereto. Similarly, the face 15 opposite to the force application region, and surrounding faces 15', 15'' and 15'" within the channel section may be considered as rearwardly facing.

Referring also to Figure 2, in order to measure force applied by way of the pressure application region 13 in displacing the pedal prior to significant resistance due to brake action without unduly interfering with pedal operation or effecting permanent changes to the pedal, an actuable device involved in the measurement, a force transducer 17, is releasably secured to the control pedal 10 to effect, by actuation of the device, operating of the control pedal by way of the pressure application region.

The transducer 17 is secured by securing about the pressure application region 13 a removable interface 20 moulded to conform to the pressure application region, and securing the transducer 18 to the interface arrangement. Such a force transducer is described in detail in co-pending application number ........

JH/17/95).

The removable interface arrangement 20 is moulded to conform to the force application region by moulding in-situ on the pedal, and its structure is therefore most conveniently described by describing a method of forming the interface arrangement.

Referring to Figure 3, the method of manufacturing the interface arrangement 20 comprises disposing within an open-topped container 21, large enough to surround the force application region 13 (as illustrated by broken lines 22 in Figure 1(a)) and of such depth as to contain at least a substantial portion thereof including side walls of the channel section, a plastic material solidifiable into a rigid pressure transmissible form.

A suitable material is uncured fibre reinforced polyester resin to which a curing agent has been added.

The force application region of the pedal is coated with a mould release agent and the container is disposed inverted over the force application surface 14 from said forward direction and depressed towards it such that the floor 23 of the container is in abutment with at least a part 24 of the force application surface 14. In depressing the container floor towards the pedal, the solidifiable material, indicated at 25, is forced between the container and the pressure application region and against the generally forwardly facing sidewalls 14' and 14''.The amount of material initially disposed in the container is specifically chosen such that it is not extruded beyond the outer surface of the channel section, that is, to contact any rearward facing surface such as 15'". If such extrusion is observed, any such surplus may be removed prior to complete solidification of the material.

Conveniently, the container is a rectangular section box having a flat base and sides, and in depressing the inverted container towards the force actuation surface, the floor of the container is aligned with a desired direction relative to the force application surface such that the base of the container defines a substantially flat support surface 26.

Solidification of the material 25 is thereafter effected, in the use of a polyester resin by permitting it to cure under the action of the curing agent. The material, in solidifying may bond to the container or the latter may be separable from the solidified material, but notwithstanding the presence or absence of such a bond most conveniently they are retained together as a pair and form a force transmitting interface body 27 which is readily removable from the force application region in a forward direction.

Having formed such interface body moulded into conformity with the forwardly facing parts of the pedal force application region, to prevent inadvertent displacement during normal reciprocation of the pedal region, a retaining part 30 is mechanically secured to the body and adapted to bear on a rearwardly facing surface of the pedal.

Conveniently, the retaining part 30 comprises a lid 31 for the container 21 which is mechanically securable to the container about a substantially common periphery, possibly by way of screws of studs 32. The lid 31 is disposed adjacent a rearwardly facing surface of the force application region and carries spring means 35 arranged to extend into the container and be in compression against the rearwardly facing surface 15 of the force application region opposite the part 24 of the force application surface.

Thus the interface body 27 as provided by the container 21 and solidified material 25 therein is able to support various forces of actuable devices in relation to the control pedal whilst permitting nearly normal operation of the pedal.

The interface arrangement 20, whilst removable from the pedal, may, of course, be used directly after moulding into conformity with the pedal force application region by simply attaching the retaining part 30, and not being removed until it is no longer required. Alternatively, the interface arrangement may be moulded into conformity in advance of its required use and removed until it is required to be used.

The method described above, and the interface arrangement which results therefrom, retains the container 21 as part of the interface body 29 with the container floor in abutment with the force application surface such that the interface body effects minimal displacement of the force application surface. It will be appreciated that if it is desired to effect forward displacement of the force application surface the (possibly deeper) container may be depressed only to a proximity with the surface that leaves the body of solidifiable material overlying the whole force application surface and defines a support surface spaced therefrom.Also, the container (if suitable precautions are taken) may be removed from the solidified material such that the interface body comprises the latter only; provision for mechanically securing the restraining part thereto may be made by embedding mechanical coupling components in the material prior to solidification or by suitable drilling and/or tapping after solidification.

The retaining of the interface body against the force application surface may be achieved by other than the bias spring 35 described above. For instance, if the container is shallower in depth than the channel section of the pedal, the retaining part may simply extend across, and clamp against, the edges of the channel section (faces 15''').

The container and retaining part are conveniently formed of metal, in the form of a die-cast alloy box, but may be formed of other, non-metallic material as required. The retaining part may, of course, be other than a suitably dimensioned lid for the container.

It will be appreciated that the support surface of the interface body, whether defined by a retained container base or otherwise, may be other than a flat surface and conform to a greater or lesser extent to the existent force application region, notwithstanding that a flat support surface may provide greater security and efficient force transmission for various actuable devices supported thereon.

It is convenient, in having a flat support surface defined by a rectangular container, to have the adjacent surface substantially perpendicular thereto and providing for readily attachment of an actuable device to the support surface, for example by mounting the device on a saddle arranged which overlies, and it securable to, said adjacent surfaces.

It will be appreciated that this form of interface arrangement may be employed with a vehicle control pedal other than of a channel section form, as illustrated at 40 Figure 4. In such arrangement, often used in commercial vehicles, the force application region 41 comprises a generally convex platform 42 of steel plate supported on a web or spindle 43 of steel integral with, or connected to, an operating lever 44 formed from steel plate. The force application region has a forwardly facing force application surface 45 and opposite thereto a rearwardly facing surface 46 separated by relatively short side walls 47.An interface arrangement 50, shown in sectional elevation, is generally similar to the arrangement 20 except that the container 51 is somewhat shallower in depth and care is taken in ensuring that the solidifiable material 52 extends about sidewalls 47 but does not extend into contact with the rearwardly facing surface 46 of the platform. A retaining part 55 may comprise a lid for the container 51 or some other releasable mechanical means of attachment thereto for biasing it towards the force application surface 46.

As indicated above, the provision of such a moulded interface permits the vehicle control pedal to be actuated in conventional manner by way of the conventional force applications surface, notwithstanding the interposition of an actuable device on the support surface of the interface arrangement. It will also be appreciated that the interface arrangement may also provide a way of displacing the actual force application region of the pedal to permit actuation of the pedal by an operative with restricted reach and or strength, for example as shown ghosted at 37 in Figure 2, when the force application region effectively lengthens the lever of the pedal whilst acting through the normal force application region, and permitting force to be applied conventionally through that region, without making permanent changes to the control pedal.

Also, as illustrated by ghosted lines 38, the interface arrangement also permits correction of a linkage to a remote device. Such remote device may be a measurement device or vehicle control which responds to motion of the pedal effected by way of the support surface and/or a remote, possibly manual, control which is able to effect motion of the pedal directed thereinto by way of the support surface and the normal force application region. Such linkage may readily be provided whilst permitting substantially normal pedal operation by way of the support surface of the interface arrangement.

Claims

1. A method of releasably securing an operating device to a vehicle control pedal, having an operating arm and a force application region including a force application surface facing forwardly towards an operative, to effect, by actuation of the device, operation of the control pedal by way of said force application surface comprising, in any order, securing about the pressure application region a removable interface arrangement moulded to conform to said force application surface and securing the actuable device to the interface arrangement.

2. A method as claimed in claim 1 comprising moulding said conforming interface in situ about the force application region and attaching the actuable device to the interface for operation before said interface is removed from the pedal.

3. A method of forming a removable interface arrangement, for a vehicle control pedal having an operating arm and a force application region including a force application surface facing forwardly towards an operative, said method comprising disposing within an open-topped container large enough to surround the force application region a plastic material solidifiable into a rigid pressure transmissible form, disposing the container inverted over the force application region from said forward direction and depressing it towards the region such that the floor of the container is proximate to the force application surface and the plastic material is distributed about the force application region, aligning the floor of the container with a desired direction relative to the force application surface such that the floor of the container defines a support surface, effecting solidification of the material in conformity with the force application region but not a rearwardly facing surface thereof to define a force transmitting interface body, and mechanically and releasably securing to said body a retaining part, adapted to bear on a rearwardly facing surface of the pedal, to hold said solidified material in abutment with the force application surface for transmission of forces thereto from the support surface.

4. A method as claimed in claim 3 comprising, as a preliminary step, applying a mould release agent to the force application region of the pedal.

5. A method as claimed in claim 3 or claim 4 comprising defining said interface body including the solidified material and the container.

6. A method as claimed in claim 5 in which the solidifiable material is arranged to bond to the inner surface of the container.

7. A method as claimed in claim 3 or claim 6 in which the inverted container is depressed towards said force application region such that the floor of the container is in abutment with at least a part of the force application surface.

8. A method as claimed in any one of claims 5 to 7 in which the container is formed of metal.

9. A method as claimed in any one of claims 3 to 8 comprising forming said support surface substantially flat.

10. A method as claimed in claim 9 comprising forming the surfaces of the body adjacent the support surfaces flat and substantially perpendicular thereto.

11. A method as claimed in any one of claims 5 to 10 comprising forming said retaining part from a lid for the container and mechanically securable thereto about its periphery and disposing said lid adjacent said rearwardly facing surface of the force application region prior to securing it to said container.

12. A method as claimed in any one of claims 3 to 11 comprising providing spring means on said lid retaining part arranged to extend in a direction towards said container and causing the spring means to be in compression against a rearwardly facing surface of the force application region opposite to the force application surface when the lid is secured to the surface body.

13. A method as claimed in any one of claims 3 to 12 comprising forming attachment points on said interface body on surfaces thereof adjacent to said support surface arranged to secure a device received on said support surface.

14. A method as claimed in any one of claims 3 to 13 comprising removing excess material from a position contactable with a rearwardly facing surface of the force application region of the pedal prior to complete solidification of the material.

15. A method as claimed in any one of claims 3 to 14 comprising disposing within the container an uncured reinforced polyester resin compound.

16. A method of forming a releasable interface for a vehicle control pedal having an operating arm and a force application region substantially as herein described with reference to, and as shown in, the accompanying drawings.

17. A method as claimed in claim 1 or claim 2 comprising forming said conforming interface by a method as claimed in any one of claims 3 to 16.

18. A removable interface arrangement for a vehicle control pedal having an operating arm and a force application region including a force application surface facing forwardly towards an operative, the arrangement comprising a force transmitting interface body moulded to conform with, and surrounding, the forwardly facing surface of said force application region and including a support surface formed therewith overlying said force application surface, said interface body being removable from the force application region in said forwardly facing direction, and a retaining part releasably securable to the interface body and adapted to bear against a rearwardly facing surface of the pedal to hold said interface body in abutment with the force application surface for transmission of forces thereto from the support surface.

19. A removable interface arrangement as claimed in claim ....

in which the interface body comprises a cured reinforced polyester resin.

20. A removable interface arrangement as claimed in claim 18 or claim 19 in which the support surface of the interface body is substantially flat.

21. A removable interface arrangement as claimed in claim 20 in which the surfaces adjacent to the support surface extend substantially perpendicularly thereto.

22. A removable interface arrangement as claimed in any one of claims 18 to 21 in which the interface body comprises an open topped container containing a solidified plastic material moulded in situ into conformity with said forwardly facing force application region, the floor of the container defining the support surface.

23. A removable interface arrangement as claimed in claim 22 in which the solidified material is bonded to the interior surface of the container.

24. A removable interface arrangement as claimed in claim 22 or claim 23 in which the retaining part comprises a top for the container, adapted to be secured thereto at a plurality of points about its periphery when disposed adjacent a rearwardly facing surface of the pedal, carrying therein spring means arranged to extend to said rearwardly facing surface of the force application region and operable to bias the floor of the container towards said force transmitting surface.

25. A removable interface arrangement as claimed in any one of claims 18 to 24 in which the side walls of the interface body adjacent to said support surface are adapted to receive attachment means for a said actuable device.

26. A removable interface arrangement substantially as herein described with reference to and as shown in any one of Figure 2 to 4 of the accompanying drawings.

27. A removable interface arrangement as claimed in claim 18 manufactured by the method of any one of claims 3 to 16.

28. A method as claimed in claim 1 or claim 2 comprising securing about the pressure application region a removable interface arranged as claimed in any one of claims 18 to 27.