"A spring of a caliper of a disc brake"

[0001] . Field of the invention

[0002] . The present invention refers to a spring of a caliper of a disc brake.

[0003]. In particular, the present invention refers to a spring capable of avoiding the knocking of the pad against the rests of the caliper body suitable to be arranged astride a disc of a brake disc. Said spring comprises a sheared and bent laminar body which extends along a line of development in a substantially tangential direction, i.e. the circumferential direction, when the spring is mounted on a caliper and in operating conditions. This spring is suitable to be interposed between an edge of a support plate of a pad and at least one wall of a caliper body to influence the pad at least in a tangential direction when the spring is mounted on a caliper and in operating conditions. This spring is shaped so as to be arranged astride the edge of the support plate in proximity of a radially outer edge thereof and arrange the laminar body astride a radially outer edge of the support plate.

[0004] . State of the art

[0005] . As known, in brake disc calipers opposite pads are pressed, due to the action of at least one piston, against opposite braking surfaces of a braking band of the assocxable brake disc.

[0006] . This piston is usually accommodated in a cylinder .obtained in the body of the caliper and it is energized by a brake fluid pressurized by a brake pump, usually of the pedal activated type.

[0007] . Braking calipers where the piston, or pistons, are energized electronically, for example by rotating a worm screw accommodated in the body of the piston and rotated by an electric motor, or more commonly by a reduction gear, are also known.

[0008] . The prior art pads are generally subjected to unpleasant vibrations, swaying and noise that particularly occur during the step of approaching of the pad to the disc and light braking.

[0009] . Examples of known braking pads are for example described in US-A-4940119.

[0010] . Document EP01709341, of the same applicant, shows spring for a caliper of a brake disc comprising a cut laminar which extends along a curvilinear line of development. This known spring is suitable to be interposed between a side of a support plate of a pad and walls of a body to maintain the · pad compressed between two springs and against walls of the body of the caliper, in which the spring has a base portion of which comprises a loop having a position and shape such to wind a corresponding lateral wing of the pad.

[0011] . Though allowing overcoming the problem related to the knocking which occurs when the plate impacts against the body of the caliper, the known solution requires a specific and particular geometry both in the shape of the plate and the body of the caliper, and thus it can be utilized only after completely re-designing the brake . [0012]. Thus, there arises the need of providing a spring of a caliper of a disc brake capable of allowing application in disc brake disc calipers already available in the market, as well as in new-concept calipers but designed in a way not to allow modifications on the overall dimension of the pads.

[0013] . Thus, there strongly arises the need to provide a spring of a caliper of a disc brake especially capable of allowing avoiding the knocking of the pad against the rests provided on the caliper body in particular when changing the motion of the vehicle, for example shifting from a forward to reverse gear of the vehicle.

[0014] . Solution

[0015] . Thus, an object of the present invention is to provide a spring, as well as an assembly spring pad and a caliper, capable of allowing attaining the aforementioned needs, as well as overcoming the drawbacks of the aforementioned state of the art.

[0016] . These and other objects are attained by a spring according to claim 1 and pad and spring assembly of claim 9, as well as a brake caliper according to claim 10.

[0017] . Some advantageous embodiments are subject of the dependent claims.

[0018] . Figures

[0019] . Further characteristics and advantages of the assembly according to the invention shall be more apparent from the description of its preferred embodiments outlined below, provided by way of non-limiting example, with reference to the attached figures, wherein :

[0020] . - figure 1 represents - in a partly sectioned axonometric view - a brake disc caliper arranged astride a brake disc wherein the pad is subjected to impacts or knocks against the surfaces of the body of the caliper when braking in case of change of direction of travel;

[0021] . -figure 2 represents - in axonometric view - a detail of the caliper of figure 1 in which springs according to the invention are applied to the ends of both pads;

[0022] . - figure 3 represents - in axonometric view - a detail of the solution of figure 2 according to a different point of view and focusing only one spring;

[0023] . - figure 4 represents - in axonometric view - a spring according to one embodiment of the invention;.

[0024] . - figure 5 represents - in axonometric view - a spring according to a first embodiment arranged astride an upper edge of a pad, in which the actions exerted by the caliper on the spring are outlined;

[0025] . - figure 6 represents - in axonometric view - a detail of the solution of figure 5;

[0026] . - figure 7 represents - in axonometric view - a detail of a caliper in which two springs according to a further embodiment are provided, applied to the edges of two opposite pads;

[0027] . - figure 8 represents - in axonometric view - a detail of a pad to which a spring is applied according to the invention; [0028] . - figure 9 represents - in axonometric view - the spring of figure 8 in which the actions exerted on the spring and by the spring to the pad are outlined;

[0029] . - figure 10 represents - in axonometric view - a spring according to a further embodiment;

[0030] . - figure 11 represents - in a different but still axonometric view - the spring of figure 10;

[0031] . - figure 12 represents a detail - in axonometric view - of a caliper on which two springs are applied to the ends of two opposite pads obtained according to a further embodiment;

[0032] . - figure 13 represents a detail according to a different point of view of the caliper of figure 12;

[0033] . - figure 14 represents a further detail according to a further point of view of the caliper of figure 12;

[0034] . - figure 15 represents - in axonometric view - a spring according to a further embodiment;

[0035] . - figure 16 represents the spring of figure 15 - in axonometric view - according to a further point of view;

[0036] . - figure 17 represents - in axonometric view - the spring of figure 15 according to a further point of view;

[0037] . - figure 18 represents a detail of a spring according to a further embodiment applied to a plate of a pad housed in a caliper;

[0038] . - figure 19 represents - in axonometric view - a spring according to an even further embodiment;

[0039] . - figure 20 represents - in axonometric view - with a different point of view of the spring of figure 19.

[0040] . Description of some preferred embodiments

[0041] . With reference to the aforementioned figures and according to a general embodiment, a spring 1 of a caliper 2 of a brake disc, caliper which is suitable . to be arranged astride a disc of a brake disc 15, comprises a sheared and bent laminar body 3 which extends along a line of development arranged substantially in tangential direction T-T, when the spring is mounted on a caliper and in operating conditions.

[0042] . The ^' figures show the axial direction A-A as a direction coincident or parallel to the rotation axis of a brake disc on which the caliper is arranged astride. R-R is instead used to indicate a radial direction i.e. a direction transverse to the axial direction and directed radially to the disc. T-T is used to indicate a tangential direction i.e. transverse to the axial and radial direction, or circumferential direction. In particular, indicated in figure 1 - with a two ends arrow - is the direction towards which a pad moves in the caliper resting thereon or knocking against it in case of braking and change of travel direction of the vehicle.

[0043] . Said spring 1 is suitable to be interposed between an edge 4 of a support plate 5 of a pad 6 and at least one wall 7 of a caliper body 8, with the aim of influencing the pad 6 at least along a tangential direction T-T, when the spring 1 is mounted on a caliper and in operating conditions.

[0044]. The spring 1 is shaped so as to be arranged astride the edge 4 of the support plate 5 in proximity of a radially outer edge thereof when the spring is mounted on a caliper in operating conditions. Said spring 1 arranges its laminar body 3 astride a radially outer edge 9 of the support plate 5. .

[0045] . According to one embodiment, this laminar body 3 of the spring comprises a flap portion or a tongue portion or a tab portion 10 bent as a bending spring.

[0046] . ^■ According to one embodiment, said laminar body 3 comprises a first hooking portion 11 for resting on a radially outer portion of said plate edge 4 in a portion thereof substantially facing said wall of the caliper body 7. Said first hooking portion 11 has at least one C-shaped portion 12 to be arranged astride the aforementioned plate edge 4 with a first arm of the first hooking portion 13 adapted to rest on a first inner surface of the plate 14 which is facing the centreline plane of the brake disc 15. Said first hooking portion 11 further comprises a second arm of the first hooking portion 16 which is adapted to rest on a second outer surface of the plate 17 opposite the centreline plane of the brake disc 15.

[0047] . According to one embodiment, said laminar body 3 further comprises a second hooking portion 18 for resting on a radially outer portion of said plate edge 4, in which said second hooking portion 18' comprises a first arm of the second coupling portion 19 adapted to rest, with at least one portion thereof, on a first inner surface of the plate 14 facing the centreline plane of the brake disc 15, and a second arm of the second coupling portion 20 adapted to rest, with at least one portion thereof, on a second outer surface of the plate 17 opposite the centreline plane of the brake disc 15.

[0048] . According to one embodiment, said bent tab portion 10 comprises iat least one first tab arm 21 which faces a second tab arm 22 and is connected thereto by means of a tab elbow 23.

[0049] . According to one embodiment, said first tab arm 21 is adapted to face said wall of the caliper body 7.

[0050] . According to one embodiment said first tab arm 21 is attached cantilevered to the remaining part of the laminar body 3 so as to avoid resting on the support plate 5 but only rest against the wall of the caliper body 7 or, in deformed conditions, rest against said second tab arm 22.

[0051] . According to one embodiment, said bent tab portion 10 is suitable to stress the pad 6 at least tangentially T-T so as to maintain the pad 6 compressed between two springs arranged on the opposite ends of the support plate 5 and against opposite walls of the body of the caliper 7.

[0052]. According to one embodiment, said bent tab portion 10. is C or capsized U-shaped and it is attached cantilevered to the first hooking portion 11.

[0053] . According to one embodiment, when the spring 1 is mounted on a support plate 5, at least the bent tab portion 10 projects cantilevered from the support plate 5 above the pad or the friction material 24 thereof, resting on the wall 7 of the caliper body 8.

[0054] . According to one embodiment, said spring 1 with the bending of its bent tab portion 10 resting on the wall 7 of the caliper body 8 is suitable to influence said pad in tangential direction T-T) when the spring is mounted on a caliper and in operating conditions, preventing the support plate 5 from striking with impact on the wall 7 of the caliper body 8 also in case of braking with change of the direction of travel of the vehicle.

[0055] . According to one embodiment, said bent tab portion 10 has said first tab arm 21 and said second tab arm 22 arranged on a plane different from the plane which accommodates every part of the first hooking portion 11.

[0056] . According to one embodiment, said second tab arm 22 is connected to said first hooking portion 11 through a connecting elbow 25.

[0057] . According to one embodiment, said tab elbow 23 develops on lines parallel to a radial direction R-R, when the spring is mounted on a caliper and in operating conditions.

[0058] . According to one embodiment, said tab elbow 23 faces with its convex elbow part 26 towards the internal of the caliper or the centreline of the brake disc, when the spring is mounted on a caliper and in operating conditions.

[0059] . According to one embodiment, said tab elbow 23 develops on lines parallel to an axial direction A-A, when the spring is mounted on a caliper and in operating conditions. [0060] . According to one embodiment, said tab elbow 23 faces with its convex elbow part 26 towards the external radial direction or towards the external of the caliper, when the spring is mounted on a caliper and in operating conditions.

[0061] . According to one embodiment, said second tab arm 22 is substantially arranged coplanar to at least one portion of said first hooking portion 11.

[0062] . ^' According to one embodiment, said second tab arm 22 is substantially adapted to face the edge of the pad support plate 4, when the spring is mounted on a caliper and in operating conditions .

[0063] . According to one embodiment, a portion of the first hooking portion 11 arranged between said first arm of the first hooking portion 13 and said second arm of the first hooking portion 16 comprises a fold suitable to be arranged parallel to the edge of the pad support plate 4, when the spring is mounted on a caliper and in operating conditions.

[0064] . According to one embodiment, a portion of the first hooking portion 11 arranged between said first arm of the first hooking portion 13 and said second arm of the first hooking portion 16 comprises a fold arranged transverse to the longitudinal extension of the second tab arm 2 so as to facilitate the bending deformation of said arm 22 when the pad 6 is stressed in abutment against the wall of the caliper body 7.

[0065]. According to one embodiment, said second hooking portion 18 comprises opposing snap-wise engagement sheets 27, 28 which project cantilevered and have free bent ends 29 approaching each other .

[0066] . According to one embodiment, said free bent ends 29 are adapted to be inserted snap-coupled into a seat or slot of the support plate 30 provided in proximity of the edge 4 of the support plate 5.

[0067] . According to one embodiment, said free bent ends 29 are adapted to be inserted snap-coupled into a seat 30 for the attachment to the plate of balancing or anti-vibration masses of the pad 6.

[0068] . According to one embodiment, said second hooking portion 18 comprises an arm of the second hooking portion 31 which extends radially cantilevered to be connected to the radially outer edge of the support plate 9.

[0069]. According to one embodiment, said first hooking portion 11 is attached to said second hooking portion 18 interposing a portion forming a slot 32.

[0070] . According to one embodiment, said slot is suitable to accommodate a pad suspension pin 33.

[0071] . According to one embodiment, said slot has such dimensions as not to interfere with said pad suspension pin 33, avoiding rubbing and the formation of residual actions interfering with the operation of the caliper 2.

[0072] . In the figures, an assembly is also represented comprising a pad 6 and a spring 1 as defined in any of the preceding _ embodiments .

[0073] . In the figures, a caliper is also represented comprising an assembly as defined above.

[0074] . Due to the reaction of the proposed spring the shoulder or abutment surface provided on the body of the caliper, as described in any of the preceding embodiments, it is possible to obtain the damping of the tangential motion of the pads.

[0075] . The simplicity of the proposed solutions shows how they neither require any design variation on the existing forms nor additional machining operations, thus greatly facilitating application on the previously installed and thus on solutions already available in catalogues and in the market.

[0076]. Given that the caliper body and pads do not require design modifications they marginally affect the weight of the brake though drastically improving their performance in terms of comfort and travel and when changing- the direction of travel of the vehicle.

[0077] . In addition, the proposed solutions, can be instantly applied to existent calipers for example during periodic maintenance for checking or replacing friction materials, such as the pads or the brake disc.

[0078] . Obviously, the proposed solutions can also be applied to caliper models different from the represented ones, for example brake calipers of the floating type as well as brake calipers that can be used both on motor vehicles and motorbikes.

[0079]. One of the main advantages of the proposed solutions lies in having- a bent tab portion which allows a considerable deformation, thus allowing controlling the elastic action of the spring, as well as a suitable load or preload design between the pad and the body of the caliper, also in conditions non-abutment of the pad against the body of the caliper.

[0080] . For example, the solutions of proposed springs may be used for interposing a spring between the body of the calipers and the pad in the side thereof facing the reverse direction of travel. The travel or movement of the bent tab portion allows exerting a load or an elastic action between the body of the calipers and the plate of the pad preloading the plate so as to avoid a discontinuity of the elastic action at all times, shifting from the forward movement to the reverse movement of the vehicle and thus making the change of position of the of the pad in the caliper extremely fluid, hence avoiding any kind of vibrations or impacts even were dust or dirt to accumulate in the caliper.

[0081] . The assembly according to the invention may be subjected, by a man skilled in the art with the aim of meeting specific needs, to numerous modifications and variants, all falling within the scope of the invention, as defined in the claims that follow.

[0082] . According to one embodiment, the second hooking portion 18 is arranged astride the radially upper edge of the plate of the pad and it is suitable to accommodate - resting thereon - a second spring 34 for moving the pads away from the brake disc arranged between the two opposite pads received in the, caliper and suitable to influence them moving them away from each other and thus from the brake disc. The action of this second spring 34 presses the spring 1 resting against the edge of the plate thus avoiding the rotations or movements thereof even further.

[0083] . According to one embodiment, said first hooking portion 11 has a transverse fold, for example which extends in radial direction R-R when the spring is mounted operating conditions, which allows a slight movement of the first hooking portion on the edge of the plate so as to allow the snap-movement in position of the opposing snap-wise engagement sheets 27, 28.

[0084] . According to one embodiment, said body of the laminar spring is obtained by shearing and bending from a sheet, for example sheared and bent or alternatively laser sheared and bent .

REFERENCES

1 spring

2 brake disc caliper

3 laminar body of the spring

4 edge of the pad support plate

5 support plate

6 pad

7 wall of the caliper body

8 caliper body

9 radially outer edge of the support plate

10 bent tab portion

1 first hooking portion

2 C-shaped portion of the first hooking portion 3 first arm of the first hooking portion

4 first inner surface of the plate

5 brake disc

6 second arm of the first hooking portion 7 second outer surface of the plate

8 second hooking portion

9 first arm of the second hooking portion 0 second arm of the second hooking portion 1 first tab arm

2 second tab arm

3 tab elbow

4 pad friction material connecting elbow

convex elbow part

opposing snap-wise engagement sheets

opposing snap-wise engagement sheets

free ends of the opposing snap-wise engagement sheets seat or slot of the support plate

arm of the second hooking portion

slot

pad suspension pin

second spring of for moving the pads away from the brake disc