TITLE

Protecting cover for temporarily protective shielding parts of a brake system at a vehicle wheel

TECHNICAL FIELD

The present invention relates to an arrangement for the temporary protective shielding of parts of a braking system on vehicle wheels according to the preamble of patent claim 1 below and to a method of removing the protective cover according to the preamble of patent claim 11 below.

BACKGROUND ART

Certain parts of the braking system in motor vehicles, such as brake disks, brake drums and the like, corrode easily, since they cannot be provided with any surface coating as is the case with other parts of the vehicle. When the vehicle is in use, any corrosion occurring is worn away as soon as the brake lining is applied against the effective brake surfaces. Before the vehicle is delivered and brought into service, therefore, slight corrosion occurs on the brake surfaces, unless specific anticorrosion measures are taken.

SE 502 527 discloses the provision of covers, which are applied to vehicle wheels so that they cover the brake disk and brake caliper, following which the wheels are fitted outside. In order to remove the cover, it must be divided and the provision of some form of dividing element, which extends radially from one circumferential edge of the cover to its other circumferential edge, is already known. The dividing elements hitherto used have consisted of separately produced elements, such as wires, for example, which are attached to the wall of the cover by adhesive bonding or taping, for example.

This known dividing element has a detrimental impact on the production

costs and since the wire is usually of metal this entails an additional recycling cost.

DISCLOSURE OF INVENTION

The object of the present invention is to provide a protective cover, which optimally fulfils the function and can be produced at low cost.

A further object is to provide a method of reliably removing the protective cover.

Said object is achieved by means of the arrangement according to the invention, the characteristics of which are set forth in patent claim 1 below.

Said further object is achieved by means of the method according to the invention, the characteristics of which are set forth in patent claim 7 below.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be described in more detail below with some exemplary embodiments, referring to the drawings attached, in which:

Fig. 1 in a section through a vehicle wheel with brake parts shows shielding by means of a protective cover of the type in question, represented schematically as an example,

Fig. 2a shows a view of the protective cover shown from the inside as a concrete exemplary embodiment,

Fig. 2b is a cut-away, enlarged partial view of Fig. 2a,

Fig. 3 is a side view of the cover according to Fig. 2,

Fig. 4 is a partially cut-away view along the line A-A in Fig. 2, showing a first embodiment of a break indicator according the invention,

Figs. 5-8 are corresponding views showing various examples of break indicators according to the invention, and

Figs. 9-11 in partially cut-away sectional views along the line B-B in Fig. 4 show examples of how the break indicator is designed.

MODE(S) FOR CARRYING OUT THE INVENTION

The protective cover 1 according to the invention and its placing in the fitted state will first be described in purely schematic terms with reference to Fig. 1. The cover 1 is formed to a specific shape, more specifically to a substantially dished shape, which is substantially rotationally symmetrical about an axis of symmetry 2, which corresponds to the axis of rotation 2 of the vehicle wheel 3, to which the protective cover is intended to be fitted. The vehicle wheel 3 or the wheel unit conventionally comprises a wheel rim 4, on which a tire 5 is fitted. The wheel 3 and more specifically its rim 4 is fixed by means of bolts (not shown), the one longitudinal axis of which is indicated by the dot-and- dash line 6, to a substantially cylindrical mounting part 7, which is firmly connected to the wheel axle (not shown) of the vehicle, which extends along the axis of symmetry 2 and which encloses the wheel bearing.

The mounting part 7 is therefore a unit rotatably supported in relation to the vehicle chassis and rotates either together with the wheel axle or relative thereto, depending on the location of the wheel on the vehicle and the method of propulsion of the vehicle. The mounting unit 7 supports the part of the braking system rotating with the wheel 3, in the example shown a brake

disk 8 having two effective brake surfaces 9, 10, with which the brake lining interacts in a manner known in the art. The brake linings or the brake blocks are fitted in a brake caliper (not shown in Fig. 1), which in a conventional manner known in the art does not rotate with the brake disk. Arranged inside the brake disk 8 in this example is a protective plate 11 , which is firmly attached to the wheel suspension. This protective plate together with the wheel rim 4 protects the brake disks at least partially from dirt and splash water. In certain braking systems the protective plate does not extend to the edge of the brake disk or past the latter and therefore does not cover the rear side of the brake disk. In principle, the protective plate may be entirely absent.

The protective cover 1 more specifically has a part which forms an orbital circumferential surface 12, which in the example shown is substantially conical, and which in an outward axial direction merges into an end wall 13 or bottom wall, which if anything extends radially to the axis of symmetry 2. In the example shown this end wall is substantially plane and extends from the circumferential wall 12 up to the inner circumferential edge 14 of the protective cover, which runs in a circular arc around a central hole 15 in the cover. In its diameter, this hole is designed so that the protective cover can be fitted relatively tightly against the periphery of the cylindrical mounting part 7, and in the example shown has a peripherally extending reinforcing collar 16, which consists, for example, of at least one outer cylindrical surface which merges into one or two annular surfaces in the radial plane with an intermediate step. In this example the peripherally outer circumferential edge part 17 of the protective cover adjoins the peripheral edge 18 of the protective plate 11 fairly tightly.

The peripherally outer circumferential edge part 17 of the protective cover has an orbital step 19, which is designed to form a support against one side of the protective plate, in order thereby to define the position of the protective cover in an axial direction, that is to say along the axis of symmetry 2. This

also provides radial guidance and secure positioning in relation to the axis of symmetry 2, whilst the stepped edge part 17 constitutes a labyrinth seal, which prevents the undue ingress of dirt particles and splash water.

As can be seen from the actual embodiment according to Figs. 2a and 3, the protective cover has engaging elements 20, which in the example shown consist of snap elements, which allow the protective cover to be snapped firmly behind the peripheral edge of the protective plate. The snap function is achieved in that the snap elements 20 consist of local elevations, which therefore do not extend continuously around the entire periphery of the protective cover, but are confined to a few isolated elevations of a very limited width in relation to the entire periphery. The protective cover is in fact made of flexible plastic material, such as polystyrene, which is to a certain extent dimensionally stable, so that in the absence of deformation forces it retains its predefined shape but, when applying the protective cover, allows the elevations 20 to spring over the periphery of the protective plate and then to snap behind its edge in order to hold the protective cover fast in the fitted protective position. An edge flange 22, which extends in the radial plane and forms a reinforcing flange, is formed radially outermost.

It can be seen from Figs. 2a and 3 that, in addition to the basic form represented schematically in Fig. 1 , it is in most cases necessary, for reasons of space, to provide a local part 21 , which is both axially and radially somewhat raised and is intended to allow room for the brake caliper in the braking system. In the raised part 21 also, snap elements or hook elements 51 are provided, which can engage in the brake caliper in order to fasten the cover to this, so that the cover does not rotate with the rotation of the wheel. The purpose of the protective cover is not to seal off the space 25 hermetically, but primarily to shield and substantially close off the corrosion- prone parts of the brake system on the vehicle wheel from the surroundings, and also to protect newly painted parts, such as rims, against hot brake lining particles, which can be burned onto paint surfaces.

The protective cover can therefore serve to create a well-shielded space 25 without affecting the functioning of the vehicle. This goes a long way towards counteracting any corrosive attack to the brake surfaces in as much as splash water and other atmospheric humidity are excluded. This corrosion- inhibiting effect can advantageously be enhanced by providing the protective cover, as shown in Figs. 3 and 4, with corrosion-inhibiting agents of a type which create a corrosion-inhibiting environment in the space 25 shielded by the protective cover. Such corrosion-inhibiting agents are already known in the art and are based on the application inside the protective cover of a corrosion inhibitor, which is in chemically bound form but which is designed for slow transition to a vaporous state, creating a rust-inhibiting effect inside the space 25, which with its limited volume of air maintains a sufficient concentration of the corrosion-inhibiting agent to effectively prevent corrosion of the brake surfaces. For example, the agent may be applied to paper layer, which in the example shown extends on the inside of the wall part 13. The layer may be firmly bonded or attached to the protective cover by means of a number of staples 29. The anticorrosion agent can alternatively be applied as a layer coated on the inside of the protective cover or in some other form.

In order to facilitate removal of the protective cover 1 , it is according to the invention provided with a dividing element 26 in the form of a specially formed break indicator, which is shown in a first example in Fig. 2a and is shown on a larger scale in Figs. 2b and 4. In contrast to the prior art, the dividing element is not a separate element fitted to the cover, but is formed in the plastic wall of the cover, both over the outer, more conical part 12 and over the planer part which is intended to cover the front face of the brake disk, that is to say extending between the radially inner circumferential edge part 14 of the cover and its radially outer circumferential part 17. The protective cover is furthermore made from a deformable material, such as polystyrene, such that the protective cover at the dividing point, which occurs at 26, can be opened to a width at least equal to the diameter of the

mounting part 7, so that the cover can be slipped over this and drawn out away from the inside through the gap between the periphery of the protective plate 11 and the rim 4.

According to the invention the break indicator 26 has a chosen main direction over a radially inner line section 27 from the inner circumferential edge part 14 and towards the outer circumferential edge part 17, this line section merging into at least one radially outer line section 28, which takes a different direction from the inner line section. In the example the break indicator 26 is applied over the raised part 21 covering the caliper and is applied somewhat asymmetrically, that is to say not symmetrically about the center. This is done in order that the line section 27 will not break up the symmetrically placed snap element 51 and adversely affect its fastening function.

In the examples shown in Figs. 2a, 2b, 4, 5 and 6 the break indicator has two radially outer line sections 28, 29, 30, 31, which form a V-shape, whilst in the examples according to Figs. 7 and 8 only one outer line section is chosen.

In all the cases shown, the main direction of the inner line section 27 has been given a linear radial direction, although it can alternatively be given some other direction, such as an obliquely slanting, angled or curved direction, for example.

The radially outer line sections, irrespective of whether there are two of these or one single line, may be straight, as in Figs. 4, 5 and 8, or they may extend differently in a curved shape, as in the examples in Figs. 6 and 7. In practice the line section is three-dimensional and follows the extent of the cover wall, but the directions indicated relate to an imaginary radial plane, that is to say the plane of the paper.

Taken over its combined extent, the break indicator is designed so that the

cover will be held together, that is to say closed, in its fitted state. In the examples shown in Fig. 4 it is meant to be released in that the cover wall is fully pierced over the extent of the division, that it to say it is divided in the form of slits or cuts over its main line sections with intervening bridges 32-37, where the wall material hangs together. In the edge parts 14, 17 also, bridges 38, 39 are created in that the division is interrupted before it reaches the edges, so that the cover wall is held together. These bridges may be formed in various ways, as shown, by a single interruption in the slit or interruptions surrounded by short dividing line sections 38, 39. In a section B- B, Fig. 9 shows the fully pierced cover wall. The placing and size of the bridges is an important factor in the parting action. As shown in Fig. 4, for example, the one outer line section 29 coheres continuously to the line section 27 in the actual branch 41, whilst the second outer line section 28 has a bridge 33 in the branch.

In order to reduce the tendency to accidental splitting, for example during fitting, the pierced line sections, at least in certain exposed locations, may be provided with some form of element which inhibits the tendency towards splitting. Examples of such split-inhibiting elements are indicated in Figs. 2a, 2b and 8 and may consist of pierced apertures 42, 43, 44, 52, for example circular holes, which are located at the end of at least some of the slit-like line sections, for example, that is to say before any bridge 37, 39. In the example according to Fig. 2 and 3 the slit-like line section 27 is terminated at its radially inner end 45 by an aperture 42 before a bridge 46, that is to say an interruption to the slit towards the inner circumferential edge part 14.

In the example according to Fig. 8 the split-inhibiting aperture 43 has been applied at one end 47 of the main radial line section 48 and a split-inhibiting aperture 44 at both the outer and the inner ends 49, 53 of the slanting slit line section 50.

Alternatively, the break indicator may be a continuous weakening in the

plastic material over the entire extent from edge to edge, for example the cover wall may be more thin-walled over the extent of the dividing line section, as shown in Fig. 10, or it may be weakened by a deformation, as shown in Fig. 11.

Electing for a deviating line section in the radially outer line section 28, 29, irrespective of whether there are one or two of these, creates an outer flap part 40, 41 , which can be grasped by a suitable tool such as pliers 54, as is indicated schematically in Fig. 4. The pliers can thereby grip the material at the outer edge, basically just in front of the main line section of the brake indicator and thereby apply a symmetrical tensile stress in the direction of the line section which presents the least risk of oblique splitting and hence of incomplete separation. Pulling the flap with the pliers and possibly also turning the pliers creates such stresses in the bridges or the weakened parts that the material is fractured and the cover can be pulled out by continuing to draw the pliers outwards.

The protective cover according to the invention may alternatively take a modified form in which the protective cover is divided into two parts, having an outer dished part with a central hole similar to that in the preceding example, and an inner part which is applied to the rear side of the fixed protective plate 11. This solution can advantageously be used in embodiments such as those described above, in which the periphery 18 of the protective plate is radially smaller, equal to or slightly larger than the periphery of the brake disk 8. The two parts are here provided with mutually adjoining flanges and snap elements of the same type as in the preceding example for engagement by snap-fastening between the two parts of the protective cover instead of snap fastening over the edge part of the protective plate. For securing the inner part to the protective plate 11 , snap elements for snap fastening are correspondingly arranged around the peripheral edge 18 of the protective plate in a manner corresponding, for example, to the solution shown in Fig. 1.

The invention is not limited to the exemplary embodiments described above and shown in the drawings, but may be modified without departing from the scope of the patent claims below. In the example a break indicator 26 has been shown applied over the raised part 21 for the caliper. The break indicator can be placed elsewhere, for example diametrically opposite the part 21 , or two or more indicators may be spaced over the cover, it being sufficient to take a grip on one of the gripping flaps, for example the one that is most easily accessible. The break indicators need not be designed with split-inhibiting elements. If incorporated, these can take the form of anything from one single element to several elements, in principle at the ends of all slits and also at other critical points, for example a corner of an uninterrupted linear slit, which is angled. Instead of circular holes, other split-inhibiting elements may be chosen, for example a short cross-slit, that is to say terminated by a T-shaped end. In the case of holes, it is sufficient for these to be slightly wider than the slit, thereby affording a stop edge transversely to the longitudinal direction of the slit.