GB2624534A

GB2624534A - Pad-holding spring and pad return spring assembly, pad assembly, brake caliper

Info

Publication number: GB2624534A
Application number: GB2315577.3A
Authority: GB
Inventors: D'alessio Davide; Bosis Alberto; Crippa Cristian; Carminati Mattia
Original assignee: Brembo SpA
Current assignee: Brembo SpA
Priority date: 2022-10-14
Filing date: 2023-10-11
Publication date: 2024-05-22
Also published as: GB2624774A

Abstract

A pad-holding spring and pad return spring assembly 1 for a brake caliper 100 (fig 1) comprising at least one pad-holding spring 2 with a c-shaped section 4 arranged to receive a guiding ear 111 (fig 1) of a brake pad 103 (fig 1) and housed in a caliper body 109 (fig 1), and a pad return spring 3 configured to bias the brake pad away from a brake disc 102 (fig 2). The pad-holding spring and pad return spring are made as separate pieces and are operatively connected. The pad return spring is made from at least one wire and comprising at least one spiral winding portion 17 being constantly biased towards a retracted position.

Description

Pad-holding spring and pad return spring assembly, pad assembly, brake caliper"

DESCRIPTION

[0001]. Field of the invention

[0002], The present invention relates to a brake caliper spring assembly capable of biasing a brake pad in axial, circumferential, and radial directions to reduce vibration and move the pad away from the brake disc when braking is couple Led to eliminate or reduce the residual torque between the friction material and the brake disc.

[0003]. Background art

[0004]. Disc brake spring. assemblies configured to elastically retain and bias at least one brake pad in a brake caliper are known. [0005]. In particular, documents U520180223928, US 9677629, U88869950 and CN207989608U show spring assemblies having a pad-holding spring operatively connected to a. pad return. spring.

[0006]. Usually, the pad-holding springs retain the pads inside their seats obtained in the brake caliper without limiting the movement thereof in the axial cirection so as to reduce the vibratic,n thereof.

[0007]. me pad return spring instead biases the brake pads away from the disc atter each braking action so as to reduce or eliminate a residual bra king torgae (residual torque) due to undesired contacts between the Toads and the brake disc with the brake deactivated.

[0008], Some known solutions include spring assemblies in which.

the pad-holding spring is made in (-me piece with the pad return spring. Such springs are made from a single piece of shaped and bent sheet metal and thus it is necessary to make different types of springs for each different field of application of the disc brake. Such solutions are particularly disadvantageous in terms of production costs, since a specific spring assembly is required for each different disc brake appijcation_ [0009]. Other well-known solutions comprise spring assemblies in Chm, the pad-holding sprnd and the pad return spring are made separate shaped and bent n'recE::s of sheet metal and are then. assembled, The pad return springs can thus be customized according to the application requirements of the braking system. However, the employment of axial leaf springs, particularly in the case of highperforTanise brake applications, raises issuers of envelppe and weidht gain negatively affecting performance of the vehicle on which the brake is mounted_ [0010]. Still other solutions provide spring assemblies in which the pad-holding spring and the pad return spring are made from a shaped and bent piece of sheet metal and a wire spring., which are then assembled. Solutions of this type are known. for example from document G82257483 and U52013025981.

[0011] In this type of solutions, the pad return spring is a wire spring having at least one elastic return portion,. The elastic return portion extends in a longitudinal spring direction with one or more bends in a bending. plane comprising an axial direction, parallel to the direction the rotation axis of the brake disc, and the radial direction DerperHcriar to the axial direction. The elastic turn portion thus bends elastically in the bending plane, elastically hasthri a coupling portHr,n of the spring in the.1 direction, between an a'zially advanced position and an axis:11y retracted resting posjtHon. The spring coupling pfll-ftiOn is connected to the brake pad so that the elastic return portion biases the brake pad away from the disc once the braking action is completed.

[C012]. It was found that the geometries with which the elasnic return r7ion of the sprinri of the known solutions j;,:; bent make the idity of the elastic return portion quite signi a generati ng highly large loads applied by the spring to the pad. as the wear of the friction material. of the brake pad increases, (0013], It was found that during the assembly of the sprinc assembly to the caliper body and bake pads, given the geometry with J.arqe envelope in the asia 1 d.ir:e.ct i on. and in the radial direction, the elastic return portion can undergo impacts and/or can be accidentally biased, causing a plastic deformation in the elastic return portion which modifies the bending geometry thereof, compromising the operation, even hindering the return of the pad, resulting-in;,,n accelerated wear of the friction material and an increase in the maintenance operation s on the brake caliper or a disc brake.

[C014]. Therefore, the need to provide pad-holding spring and pad return spring assemblies is strongly felt, in which Pad return wire spring is shaped so as to prevent or reduce possible plastic deformations for the oad return wire spring during the assembly or maintenance.

(0015]. Additionally, the pad return wire springs connected to the pad-hcliHng sprinns have an envelope along the longitudinal extension thereof, in particular in the axial and/or radial direction, and a tend geometry of the elastic return portion in the bending plane which prevent them from being used for different types of calipers.

[0016]. Therefore, in the industry the need to provide pad-holding spring and pad return spring which the oad return wire sprin.g is shaped sc to simply allow higher application versatility, allowing the employment of a. bending geometry usable for a plurality of brake calipers, is strongly felt, (0017], Therefore, a need arises to manufacture spring assemblies, pad assmimiHes and brakt., calipers whHrTh are capable of simultaneously-offerlrig, during the braking, particularly efficient performance tn. reducing, or even suppressing, any residual torque at the end of braking, and vibration and noise minimization properties, while allowing high adaptability and ease of modification so as to be used in various fields o: application, and desired performance of disc brakes without affecting time and costs during the design and manufacturing, [0018], Therefore, it is the problem underlying the present invention to devise a spring assembly, a. pad assembly and a brake caliper, which hare structural and functional features such as to meet the aforesaid needs while ob-s,-,il,t-H_g the drawbacks mentioned with reference to the prior art an& meeting the aforesaid felt needs, [0019]. Solution [0020]. it is an object of the present nvention to provide a pad.-holding sprtng and pad return spiHng assembly, as well as a. brake pad assembly, as well as a brake caliper which allow reducing, if not eliminating, residual torque once a braking action is completed, and which allow increasing the braking reliability.

[0021]. These and other objects and advantages are achieved by a pad-holOHng spring,;nd pad return spring assembly according to I, as well as a. brake pad ai...sembly aceorchnq to claim. 9, as well as a brake caliper according to claim 12, [0022]. Some advantageous embodiments are the subject of the dependent claims.

[0023]. The analysis of this soluton showed that the suggested solution a 1 ILows obtaining a. pa holding spring and pad. return spring assembly in which the pad return spring is azially compact, reducing the envelope of the pad return spring and allowing a simplified assembly without the risk of an accidental plastic deformation of the pad return spring during the assembly and maintenance operations.

[0024]. The analysis of this solution showed that the suggested SO lution allows obtaining a pad-holding. spring and pad return spring assembly in which the pad return spring has a highly small axial en-re:lupe as compared to the known solution, the elastic return force being equal.

[0025]. The analysis of this solution showed that the suggested solution allows obtaHning a. pad-holding spring. and pad return spring assembly in which the pad return spring has a lower axial rigidity as compared to the known solution, the elastic return force being equal, allowing a simplified assembly ard an increase in the axial load due to the wear of the friction material which is lower than in the known solution.

[0026]. The analysis of this solution showed that the suggested solution allows obtaining a. pad-holThng spring and pad return spring assembly in which the pad return spring works in orre axThi direction. substantially by traction, avoiding the creation of elastic return. portions having bends in a bending plane cormrising the axial direction and the radial direction, which are adapted to bend for generating the elastic return force.

[0027]. The analysis of this soluton showed that the suggested solution allows obtaining -higher residual torque reduction between the pad and brake disc than the solutions of the prior art, thus a reduction in the events of uneven brake pad wear and in particular a reduction in the maintenance events.

[0028]. Moreover, the suggested solution maintains a very high, CE even improved, braking efficiency, for example the efficiency-is strongly improved by virtue of the absence of frictional contact between the pad return spring and the pad-holding spring during normal operation.

[0029]. Additionally, the suggested solutions allow increasing the service life of the pad-holding spring-and pad return spring assembly. =pared to known solutions, and drastically reducing the maintenance inietyni_Hons.

[0030]. Even additionally, by virtue of the suggested solutions, it is possible to ensure sjmple spring assembly solutions according to the desired braking performance w'Hle maintaing.., uniform pad.-hold-ing spring for varHouc, applicatinns and modjfyjng the pad return spring according to the applUcations in a highly simple manner while maintadning a small axial envelnoe of the pad rr-turn. spring. In particular, in a highly Rimple mariner, it ig possible to provide different diameters of paid return spring and/or a different number 0.f pad return sprHng windings anH/or a different winding diameter of the pan return spring windings depending on the applications required.

[0031]. Still additionally, by virtue of the suggested solutions, due to the small axial and radHal enveaope, it <:.* possible to obtain a Iree space in the brake caliper on which the pad return spring and pad-holding spring assembly is mounted, which allows a designer to add further elements.

[0032]. Drawings [0033]. Further Lea.Luiez, and advantages of tile pad-holding spring and pad return spring assembly, the pad assembly, and the brake caliper wHil become apparent from the following description of preferred embodiments thereof, given by way of non-liffiting indication, with reference to the accompanying drawings, in which: [0034]. -Figure i shows an axonomeLiic view of a brake caliper according to the present invention, comprising E caliper body, at least one tyrake pad, and least Jae pad-holding spring and pad return spring. assembly according to the present invention, which. is

B

connected to the caliper body and the at least one brake pad; [0035]. -Figure 2 snows an axonoretric view of a pad assur bay compring a pad-hold-ih_g spring and padreturn spring assembly according cc the connected io a brake pad, in which a brake disc facing the brake pad is diagrarr:jnacically shown; [0036]. -Figure 3 shows a front view of the pad assembly an Figure 2, where there is shown a pad support plate on the side opposite to the bra disc, where there is ',town the at least one spring being coaxial to the axial direci-ion which allows retu-ning re d in the axial, direct-ion; [0037]. Figure 4 shows a front view, diametric-T1 opposite to the front view in of the pad assembly in Figure 2, where there is shown the 'DJ:d friction material and the orake disc side surface of the I:Hate, where there is shown the coupling portion in contact with the brake disc side clurface of the:pl.at.e, at the ear of the pad, in which the coupling portion is bent so as to prevent an involuntary disconnection of the pad return spring from the brake pad; [0038], -Figure E; shows ometric view of the pad-holding spring and pad return spring assembly according to the Dresent avention in which the pad return spring comprises at least one wire portion comprising a winding being coaxial to the axial direction L-,o 63 to work in traction in the axial direction, and in which the end portion of the wire por*Lion forms at least one bend in a plane. perpendicular to the axial direction; [0039].Figure 6 shows a front view, oeroen _cular to the axl,ai direction, of the pad-holding spring and pad return spring assembly in Figure 5 on the brake cisc side, where in the foreground. there is shown the end portion of the pad. return spring wire portion having a bent portion in a plane perpencH]cuar to the axial direction, and where in the background there is shown the at least one winding of the pad return spring wire portion.; [0040]. -Figure 7 shows a side view, perpendicular to the tandential direction, of the pad-holding spring and pad return. spring assembly in Figure 5, where there is shown the at least one winding having a much smaller axial envelope than the envelope of the central portion of the wire:portion that connects, by axially extending, the at least one winding and the coupling portion bent in the plane pexpenicclar to the axial direct-Hon; [0041]. -Figure 8 shows an axonometric view of a. further embodiment of a pan-holding spring and pan return spring assembly according to the present invention, where there are shown two pad-holding spring and pad return spring assemblies from Figure 5, which are mutually spe.,,..ulai with respect to a central plane perpendicular to the axial direction and connected by a bridge-like portion; [0042]. Figures 9 and 10 show an axonometric view of connecting portion of the pad return spring wire portion connected to the pad-holding spring by riveting; [0043]. -Figures 11 and 12 show an axonometric view of a connecting portion of the pad return spring wire portion connected to the pad-holding spring with an opposite disc side end portion of the S--bent pad return spring so 35 to be inserted into a hole of the pad-holding spring, and the S-bent oortion in contact with oppos te surfaces of a. wall the pad-holHinri spring,,,nd retainer': by a couolincielement; [0044]. -Figure 13 shows an a2ionomeriu -c;.L.ew of the pad id_Lng spring and pad return spring assembly according to the present invention, in hinh the pad return spr_ comprises at least one wire portion comp,-Hsing a winding being coazial to the circumferential directj:on, and.in Which the end portion of the wire portion forms at least one bend in a pLarre perpendicular to the direction,

[0045], Description of some preferred. enhodiwents

[0046], According to a general embodiment, a pad--holding and pad return spring assembly I for a. brake caliper 100 is provided.

[0047]. En the following description, ness oterwse specified, the assembly 1 is described when it is in resting non,HftHon not coupled to a brake pad and/or a. caliper body.

[0048]. Said assethbly I defines an a.xial direction k--A, a radial irecLic-*npe:--pendicular to said axial direction A-A, and a 10 circumferential or tangen ial dlrectio C-r' perpendicular both to said axial direction A-A and said radial direction a-a.

[0049]. According to an embodixcent said axial direction is parallel to a rotation axis of a brake disc 102, on which a caliper body 109 of the brake caliper 100 can be placed in a straddling is manner.

[0050]. Said assetrbiy 1 comprises at least one pao--holdin spring 2 and at least one pad return spring 3, made of different semifinished products and then operatively connected.

[0051]. Said pad-holding spring 2 is configureH to be arranged between at least one guiding ear 111 of a brake pad 103 of the brake caliper 100 and the caliper body 109 of the brake caliper 100 so as to bias said brake pad 101 in the radial direction R-R and circumferential direction C-C.

[0052]. Said pad return spring 3 is configured to bias said brake pad 101 in the axial direction.2A--A away from a brake disc 102, [0053]. Said pad-hoidinq spring 2 has a main extension in the r..a.dia.I R-R and circumferential. C.-C directions, [0054]. Said pad-holding spring 2 comprises at least. one C--shaped.

c!ect7ion 4. Said Cl-shaped section 6 conipri_ses a centra: pert-ton 5, an upper portion 6, and a lower portion 7. The central portion 5 extends at least in a radial direction R--R, mainly along said radial direction B--P.. The upper cartoon 6 and the lower portion 7 extend in a cani-llevered manner:,i-least partially in the circumferential direction C-C from said central portion 5, extending from two radially opposite ends of the central portion 5. According to an embodiment, the central portion 5 extends at least in the radial Hirection R-R and the axial direction TA.-k. According to an embodiment, the upper portion 6 and the lower. portion 7 also extend in the axial direction A--1, TiccordThq to an embodiment, the upper portion 6 and the lower portion 7 extend in a cantilevered manner frpm two radially opposite ends of the central portion 5 along a longitudinal direction comprising the circumferential direction C-C and the radial direction h--P..

[0055]. Said C-shaped section 4 is adapteci to be inserted into a recess 106 of said caliper body 109 and is adapted to accommodate 'maid guiding ear 111, [0056] Said pad return spring comprises 8 anchoring portion operatively connected to said C-shaped section 4, a coupling portion 10 configured to couple said brake pad 103, and a linking arm 9 operatively connected to said anchoring portion 8 and said coupling pcmon 10. Said cowling portion 10 is elastically movable with respect no said anchoring portion S in the axial dire ---"on A-A between a retracted resting Position at least one advanced positionwi,ards said disc 102, and vice [0057]. According to an anchoring portion ambodlifent, ,aid extends from said C-shaped section 4 in the axial direction-A in a first directl, opposite to said disc 1.02.

[0058], According to an embodiment, said linking arm 9 extends from said anchoring portion 8 along a longitudinal arm direction oriented in an axial direction A.-A mainly in a second direction 20 concordant with said disc 102, opposite to said first direction.

[0059]. According an embodiment, said coupling portion 10 is elastically movable in an axial direction A-A. between at least one advanced position towards said disc 102, protracted along said second direction, and a retracted_ resting position in the opposite direction.

[0060]. Said pad return spring 3 is made from at least one wire.

[0061]. Advantageously, said pad return spring 3 comprises at least one winding portion 17 connecting said linking am n 9 to said anchoring. portion 8. Said at least one winding portion 17 comprises 5 said at least one wire spirally wound about a winding axis A, Said. winding alis A is oriented so as 1-constantly elastically bias said coupling portion 10 towards said retracted resting position along said axial directibn. A-A. In an eploodiment, said at least one winding portion 17 constantly elastically biases said coupling 10 portion 10 in said retracted resting position by avoiding the contact of said brake pad 103 and/or said pad-holding qprino: 2 with said winding portion 17.

[0062]. In an embortTent, th(, wndincl axis A is oriented. substantially parallel to said axial direction A-A, thereby it is possible to limit the axial extension of the pad return spring 3 by virtue of the windHiy portion 17 which allows storing' elastic energy hr bending the pad return spring into planes substantially perpendicular to the axial. direction A--A. Thereby it is possible to avoid bends from being created Cr the at least one wire in planes comprising the axial direction, avoiding acting with portions of the pad return spring under bending for elastically moving the coupling portion 10.

[0063]. In an embodiment, the winding axis A is oriented so as to be incident and/or perpendicular to the axial_ direction or to a direction parallel thereto.

[0064]. According to an embodiment, said winding bortion. 17 comprises a plurality of coils 31, 32: wound about said winding axis A. Tx:cording to an embodiment, the plurality of co'is 31, 32 elastically deforms by torsion, elastically biasing said coupling portion. 10 towards said retracted resting pbFliton. According to an effbodimen:L., the pad return spring 3 is bent sc, as to prevent elastic deformation by bending in the axial direction A-7,, in the linking arm 9 and/or in the coupling portion 10 and/or in the winding portion 17, during normal operation.

[0065], According to an ernbodiraent. said pluraThltv of coils 31, 32 comprises at least a first col] 31 and a second coil 32. According to an embodiment, each coil 31, 32 substantially has the same outer diameter. According to an errhodiment, the coils of the plurality of coils 31, 32 have a plurality of different outer diameters.

According to an embodiment, said -plurality of coils 31, 32 is concentric. Accordi=, to can embodiment, said olu-ality c-f coils 31, 32 is misaligned. According to an embodiment, said plurailtv of coils 31, 32 forms a cylindrical or conical helical spring portion, [0066]. According to an eMoodiment, said at least one wire has a wire diamet_et. Acc.ordin,L1 t.c. an embodiment, said winding portion 17 has a winding pitch between said wire diameter and 4/3 of the wire diameter. According to an embodiment, said winding pitch is defined as the distance along the axial direction A-A between the center of at least two adjacent coils.

[0067]. According to. an embodiment, said winding port-Ion 17 defdnes a first axial pan return spring envelope Al. Said linking arm 9 and said coup] portion 8 define a. second axial Ari return spring envelope R2. Said first axial pad return spring envelope A.1 is less than the second axial pad return spring envelope Al.

[0068], According to an embodiment, said winding ornion 17 defines a first radial pad return spring,-r-lope RI. Said coupling portion B defines a second radial pad return spring envelope R2. The radial pad return spring envelope R] is smaller than the second radial pan return spring envelope [0069]. According to an embodiment., said winding portion 17 is bent under winding. with respect to said winning axis A accord:tng to a winding direction, in which coupling portion 10 is bent at least. partially in a direction cppos to to it" winding direction.

[0070]. By virtue of the provision of the winding portion 17, it is possible to significantly reduce the axial envelope of assembly 1, by reducing, even eliminating, the probability of plastically deforming the pad return spring. 'Are during the assembly operations of assembly I to the brake pad 103 and the caliper body 109. By virtue of the bending geometry of. the pad return spring as a. spiral winding of the wire,-,bout the winding axis A, it is possible to provide an elastic energy storage. port Ion which lasts over time and is highly resistant to impacts in the circumferential or radial directions during the assembly.

[0071]. By virtue of the provision of the winding. portion 17 which allows obtaining a smali envelope in the axial direction. AA of the pad return spring 3, while maintaining hich resistance, high elastic. retur:n for ce applicable to the pad" and high reliabilit.y over time, ills possibleto mount the assembly I on several geometries of existing calipers. Additionally, by virtue of the small envelope in the axial direction A-Ts of the pad return spri it is possible to provide new calipers having small dimensions or introduce other elements by virtue of the small axial envelope.

[0072]. By virtue of the provision of the winding portion 17, it is possible t.o reduce the axial 1-Hgi pad return spring 3 with respect to pad return springs inclLdioq elastic return arms with bends and extension in planes comprising the axial direction. Thereby, on the one hand, it is possible to support and elastically return the pad in a highly r iable inner even under conditions of extreme wear of the friction rjal, and on the other hand it is possible to obtain reliable results in a. broader range of geometric tolerances as compared to the known solution.

[0073], Ey virtue of the provision of the,,,indIng portd on 17, it is possible to increase the longitudinal length of the wire of the pad return spring 3 without increasing the axial, envelope or keeping 20 the axial envelope very low as compared t.c. the known solution. By of the provision of the winding portion 17, is possible to-bend the wire spring about a winding axis which is oriented in the same direction as the elastic return force to) he applied to the oad. By virtue of the provision of the winding portion 17, the return forces applied to the pad are due to the torsional deformations of the coils of the winding ',portion, avoiding the generation of elastic. forces by bending in. the axial direction.

[0074] . According to an emboOdment, said isuxnu arm 9 comprises an arm end portion 15 directly connected to said coupling portion 3.

Said arm end perti on 16 is arranged at a first distance D1 along said c: rcumferential,lirectioll C.-C with respect to said central portion 5 or a radial extension and/or axial extension thereof. Said coupling portion. 1.0 comprises a first stretch 22, which is arranged at a second distance DO along-said citcumferenti al direction CO--C from said central por; on 5.

[0075] . Advantageowsly, said second distance DO is less than said first. distance Di. In the case of circumferential sliding of the coupling portion 10 with respect to the brake pad 103 toward.s said central portion 5, during the assembly and/or during very aggressive wear conditions of the friction material, said first stretch 22 thus interferes with said central. port1Dn 5 first preventing said arm end portion 16 from contacting said central portion 5, thus preventing the coupling portion 10 from uncoupling from the brake pad 1103 on the one hand, and 1 imi ting any frict ion forces generated between the pad return spring. 3 and the Le:ILLal portion " of the pad-holding spring.

[0076] . According to an embadimnt, said f irst stretch 22 has a has free spring end 23. According to an embodiment, said free spring. end 23 faces said central portion 5. According to an 25 enbodiment, said free spring end 23 is defined by a surface of a section of the wire of the pad return spring 3. According to an embodiment, the free spring end 23 has a smaller surface than the surface of a circle having the eiameter of the pad return spring wire as a diameter. According to an enLbdiment, said free spring end 23 is configured to interfere with said central portion 5. Thereby it is possible to limit the contact surface between the pad return spring 3 and the central portion 5 in the case of accidental circumferential sliding of the coupling portion 10.

[0077]. According to an embodiment, said coupling portion 10 camp_rises second stretch 24. According to embodiment, said second stretch 24 and said first stretch 22 are connected, forming a coupling portion angle. According to an embodiment, said coupaing portion angle is an acute anglc, facing the central portion 5. According to an embodiment, said second stretch 24 and said first stretch 22 are connected, forming a concave portion where said concave portion faces the central portion 5.

[0078], According to an embodiment., the second stretch 24 and the first stretch 22 are arranged or lie on the same coupling portion plane, in which said coupling portion plane is pecendicuiar to said axial direction A-A. According to an embodiment, the second stretch 24 and the fLtsb stretch 22 form a V-bent portion_ The provision of the first stretch. 22 and the second stretch 24 allows obtaining. a coupling portion 10 capable of resisting the stresses of the brake pad in a highly reliable manner even under conditions advanced wear of Lhe friction material_ [0079]. According to an embodiment, said first stretch 22 is a straight wixe stretch, said second stretch 24 is a straight wire stretch, where said second stretch 24 and said fir-st stretch 22 are connected by a third stretch 25, where said third stretch 25 is curved. Rccording to an embodiment, said second stretch 24 is inclined in the coupling portion plane by a second stretch angle between 0 and 45 degrees with respect to said radial direction R-R, preferably between 15 and 30 degrees.

[0080]. By virtue of the arrangement and geometry of the coupling port-ion 10, should a frictional contact occur between the pad return spring and the pad-holding spring, the surface of the pad return spring contacting the pad-holding spring is sianificantiv reduced as compared to the known solution.

[0081]. By virtue of the provision. of the first stretch 22 of the coupling portion 10, with an end portion. 23 thereof arranged faring said central wail 5 at a circumferential distance from the central wall 5 of the pad-holding spring. 2 less than the circumferential esistarloe from the central wail 5, or from an amdic,,--radial tz.i.ension thereof, of every other stretch of the coupling portion 10 and/or linking arm is possible to limit the contact area between the return spring and the pad-holding spring due to a possible tangential sliding of the pad return spring on a disc side surface of the br:ikc, pad, to a fraction of a cross section of the pad return spring wire, on the one hand thus reducing any generatahle friction force, and or the other hand avoiding a wire spring portion from becoming stuck between the brake pad and the pad-holding spring., or even being removed from the brake pad, thus losing the connection.

[0082]. According-to an embodiment, said anchoring portion 8 has least a fist straight stretch 19, which extends away from the brake 02, where said first straight stretch 19 is parallel to rue axial direction I----Tu According to an embodiment, said anchoring portion 8 has at least a first curved stretch 13 connectinoi said wi dlnq oortion 17 to said first straight stretch 19 to as to arrange the winding axis A of the T. ding portion i.i parallel or perpendicular and/or incident to the axial direction A-A. According. to an ei-ieodimen, said winding portion 17 extends in a helical manner in the direction of said brake disc 102. According to an embodiment, the first cur-ved. stret:h 18 is bent at a right angle. [0083]. According to an embodiment, said linking arm 9 is substantially straight and parallel to said axial direction A-A_ According to an embodiment, during normal operation of the assembly, said linking arm 9 avoids elastically biasing the coupling portion 10 in the axial direction, for example by bending.

[0084]. AcccrdincT to an embodiment, said linking arm.

connected to said winding portion by means of a first curved connection 33 that forms a right angle with said winding portion in a. plLaine comprising at least said axial direction,,., so as to arrange said linking arm 9 parallel to said axial direction -A.

[0085]. According an nrthodiTnterlt said second stretch.24 is connected to said arm end portion 16 and/or said linking arm 9 by means of a second curved connection 34, substantially taming a right angle between said linking arm 9 and said coupling portion 10.

[0086]. According to an embodiment, said anchoring portdon 8 has a second straiaht stretch 21 connected to said first curved stretch 18. According to an embodiment, said anchoring. portion 3 has a second curved stretch 20 -From which the winding portion 17 extends, where the second curved stretch 20 and the second straight. st.reb_h 21 lie at least partially on a plane perpendicular to the axial direction [0087]. According to an embodiment, said pad-holding spring 2 10 comor:ses a coupling wall 13, where said anchoring portion 8 of said pad retur.n spring 3 is anchored to said coupling wall 13 of said pad-holding spring 2, [0088]. According to an emodtment, said anchoring portion 8 is coupled at. least to one surface of said coupling wall 13 facing. the 15 concavity delimited by the C--shaped section 4 in the radial direction [0089] According to an embodiment, said pad-holding spring 2 comprises coupling element 14, connected to said coupling wall. 13.

According to an embodiment, said coul.Dling element 14 comprises at least a pair of coupling tabs 15 configured to tighten at leas.... one portion of said anchoring pnrtion 8. According to an embodiment, the pair of coupling tabs 15 is tightf-ned no the first straight stretch 19 of the anchoring-portion S. According to an embodiment, said anchoring. portion 3 of said pad return spring 3 is riveted to said coupling wall 13. In an embodiment, said anchoring portion 8 of said pad return. =ring 3 is welded to said coupling wall 13. in an embodiment, said anchoring port.ion 8 of said pad return spring 3 is coupled bv interference to sa-id cr,upind wall 13. in ar embodrent, said anchoring portion 8 of said pad return spring 3 is connected to said coupling wall -fl ezclusjvely by welding.

[0090]. According to an embodiment, said anchoring portion 8 comprises a third straight stretch 34 connected to said first straight stretch 19 by means of a third curved stretch 35 so as to form an S--bent anchoring portion end portion_ 'According to an embodiment, the first straight,,tretc_h 19 is in conact with a lower surface of the coup] wall. 13 facing the opposite side with respect to the enclosed. portion. of the C--shaped. section. 4. According to an amboWment, the coupinq wall 13 has a through hole in wh-ich aL least one portion of the anchoring portion 8 is inserted.

According to an embodiment, the third curved stretch 35 is inserted into the hole of the coupling wall, and the th,Hrd straight stretch 34 is in contact with an upper surface of the coupling. wall 13, facing the enclosed portion of the C--shaped section 4, radially apposite to said upper surface of the coupling wall 13 so as to connect the pad return spring 2 to the pad-holding spling According to an embodHment, said anchoring port Hon 8 comprises a third straight stretch 34 connected to said first straight stretch 19 by means of a third curved stretch 35 as to form an 1-,-bent anchoring portion end portion.

[0091]. According to an embodiment, said pad-holding spring 2 comprises a first cantilevered portion Ii operatively connected to said lower portion 7 extending in a cantilevered. manner in an. axial direction 2.--T, in. the direction opposite to said brake disc 1.02, where said pad-holding spring. 2 comprises a second cantilevered portion. 12 operatively connected to...!:9i.d 1--Hrst cantilevered portion.

II extericHr,9 in a nantdevered manner in a circumferential direct iron C-C, where said anchoring portion 8 of said pad-holding spring 2 is fired to said second cantilevered portion 12, where said second cantilevered. portir.n. 19 comprises TaHd coupling wall 15.

[0092], P...cordlip.j Loan emboHment, said assembly 1 couprises two pad-holding springs 2, two pad return springs 3, and a bridge-like portion. 36 connecting said two pad-holding: springs 2.

[0093]. According to an embodiment, situ pad return serng 3 is made with two par,lle 1 wires placed side-by-side.

[0094]. According to an embodiment, said pad--holding spring 2 comprises an L-shaped section 25 seamlessly operaLivelv connected to said C-shaped section 4. According to an embodlnent, said f-shaped section 26 comprises a. first support portion 27 operatively connected perpendHcciarly fr, a second support portion 28. According to an embodir=t, the first support. portion 27 extends perpendicularly from said upper portion 6 of said C-shaped section 4 so as to obtain, with said upper portion. 6 and said second support portion 28, a U-shaped section fla.VinOI concavity opposite no said C'--shaped section 4. According t.o an embodime.mt, the central portion 5 of said C-shaped section 4 comprises a first retaining element 29 which extends in a cantilevered manner in a circumferential direction c--c: outside the concavity of said C-shaped section 4. According to an eMbcent, said T-shaped section 26 comprises an opening between said first support portion 27 and said second support portion 28, and said first support. portion 27 ccmprHses a second retaining element 30 which extends in a cantilevered manner in a circumferential direction C-C into said opening. According to an embodiment, said first support portion 27 comprises a pair of retaining elements which project from opposite edges in a circumferential direction C-C into said L-shaped section 26, [0095]. In an embodiment, the brake pad 103 is an outer side brake pad or an inner side brake pad, where the outer side brake pad is further spacerl apart from the vehicle as compared to the Hnner s-ide brake pad. In an embodiment, the 'pier side brake pad is adapted to I1 5 be biased directly by thrust means or pistons of the brake caliber, and the outer side brake p.:=1d is adapted to he biased indHrectly by said thrust means or pistons of the brake caliper by means of a portion of the floating element 110 of the caliper body 109. In an embodiment, each pad return ctprHng 3 connected and/or adaDted to be connected to the outer side brake pad defines an!Jut,::i side return load. in an embodiment, each pad return spring 3 connected and/or adapted to be connected to the inner side brake pad defines an inner side return load In an embodiment, .1-he inner. side return L:-,ad is equal to the outer side return load. In a brake caliper of the floating type which supports the pair-or brake pads comprising. the inner side brake pad and the outer side brake pad, once the braking a,..tion is completed, the pad return sp. lags 3 act.-ing on the inner side brake pad thus work in a aymmai-rj,c manner and ith the same elastic behavior as the pad return springs 3 acting on the outer c!icle brake pad, In an embodiment, the inner side return load is lower than the outer side return load. In a brake caliper of ti-re. floating type which supports the pair of brake pads comprising the inner side brake pad and the outer side brake pad, once the braking action is completed, rho pad return springs 3 acting on the inner side brake -ad thus work in an asymmetric marn-r with respect to the pad return sprThgs 3 acting on che outer side brake pad. By virtue of the provision of the outer side return load increased as compared. to the side return load, in additi vi to allowinc the brake PaICIS to move aw ry from the brake disc, a return force is applied by the pad return springs 3 to the floating element 110 of the caliper body in the resting position thereof by moving away from the vehicle, helping it to be partially re-centered respect to the brake disc and ensuring a complete detachment of the brake pads with respect to the disc.

[0096]. The present ±nve.ntion also relates to a brake pad assembly for a brake caliper 100 The brake pad assembly comp-rises at least one brake pad 103 and at least one pad! -holding Urinc and pad return spring assembly 1 according to any one of the embodiments described above.

[0097]. Said pad-holding spring and pad Let= spring assembly 1 connectable to said brake pad 103. Said brake 1-1(-1 103 comprises a friction material 105 and a. support. plate 104 which suppori.ts said friction material 105. Said support plate 104 comprises at least one guiding ear 111 which protrudes laterally in the circumferential direction Said C--shaped sectir,n. 4 of said rad-holHHng sorina 2 is configured to accommodate said at least. one guiding_ ear. 111 so as to bias said pad 103 in a circumferential direction C-C and a radial direction R-R. Said coupling portion 10 of said pad return spring 3 is configured to (7:Duple said guiding ear 111 to bias said pad 103 in a direction away from a ake disc. 102 by means of said Wind According. to an apart from embodiment, said poi; 0.11 17.

azialay SriEl winding porti in 17 said coupling portion 10 of at. leas._ said arm 9. According to nc errbcdiirent, said winding portion.

is partially external with respect to the footprint or the support 15 plate 104. According to an embodiment, said winding portion 17 is partially external witLi respect to the fontorint of said (..Jiding ear 111 In this description, footprint means the profile of an e ientent with respect to a plane perpendicular to the axial direction ArA.

According to an embodHment winding portion 17 avoids directly contacting said support plate 101, [0098]. According to an embodim,,n 'orate pad 103 comprises an ear side edge 11.2 which lateral l. imits said at least one guiding ear ill in the circumferential direction arid radial direction R-R. According to an embodiment, said brake pad 103 25 comprises a rear ear Quirking surface 113 facing the opposite side with respect to said friction material. 105, and a front first-ear surface 114 facing the same side as said friction material 105.

[0099]. According to an embodHwent, said ear side edge 112 is insertable into said C-shaped section 4. According to an embodiment, said coupling portion 10 is coupdable to said front first-ear surface 114 so as to bias said pad 1:13 in the axial L',Hrection Ti-A constantly in a direction opposite to said friction material 105.

[00100]. According to an embodiment, said ear side edge 112 defines at least one recess 115 del:inliter-1 radially by a radial edge ccon 115 mainly extending along said radial direction R-R and by a circumferential edge portion 1Y7 mainly extending along said circumferential ddrection. C--C. .According to an embodiment, sadd radial edge porton 116 and sad. circumferential edge portion 117 are connected in a stepped manner, where said arm end.pc,-,--tion 16 faces said. recess 115 in the radial direction k---R facing said circumfRrentlal edge 117 and in the circumferential direction C-C facing said radial erHige 116 without contacting them. Ac-cording to an embodiment, said winding portion 17 partially faces said recess 115. According to an emHodHment, said flout:ling portion 10 is in contact with said front ear surface 114 and/or with an ear corner. 107 defined by the intersect-L-3n of-said frbnt ear surface 114 and said circumferf-ntial. edge 117 delimiting said recess 115.

[00101]. The present invention also relates to a brake caliper 100 comprising at least one pad assembly according to any one of the 25 embodiments described. above.

[00102]. The brake caliper 100 comprises a caliper body 109 connectable to a vehicle and adapted to be arranged straddling-a brake disc 102, where said caliper body 109 comprises at least one brake pad housing pocket, where said housing pocket comprises at 5 least one recess 10. Said pad-holding spring 2 is interposed at least between said guiding. ear 111 and said recess 105. Said coupling portion 10 of said pad return spring 3 is coupled to said guiding ear iii to bias it in a direction away from said brake disc 102 [00103]. According to an embodiment, said caliper body 109 comp.rises a support 101 fixedly connectable to said vehicle, where said support 101. con-prises said at least one brake pad housing pocket.

[00104]. According to an embodiment, said caliper body 109 comprises a floating elembnt 11.0 connected in a floating manner to said support 101, said floating element being configured to be arrangeH str?,Iddlina said brake disc 102 and to directly or indirectly bias, by means of thrust means, said brake pad 103 along said axial direction A-A towards said brake disc 102 between. at least one pad. resting position and one pad braking position.

[00105]. According to an Embodiment, said brake disc 102 comprises a disc axis, where said axial direction A-A is parallel to said disc axis.

[00106]. According to an embodiment, said caliper body 109 25 comprises a support protuberance 1.08, where said L-shaped section. 26 is couloled to said support protuberance 108, and/or where said support 101 comprises said support. protuberance 1.08. 3c,

LIST OF REFERENCE SIGNS

1 Pad-holding spring and pad return spring assembly pad-holding spring pad return spring 4 C-shaped section 7 central portion upper portion 7 lower portion 8 anchoring portion 9 linking arm 10 coupling rs,prtion II first can portion 12: second cantilevered porton 13 coupling wall 14 coupling element 15 coupling tabs 16 arm end. portion.

17 winding. portion IS first curved stretch 19 first straight stretch.

20 second. cur-yea stretch 21 second straight. stretch.

22 first stretch 23 free spring exid.

24 second stretch 25 third stretch 26 L-shaped section first support portion second support portion 29 first retainidu element 30 second retaining element 11 r5' coil 32 second coil 33 fHT-E..1t curved connection 34 second corveci connection third straight stretch 36 bridge-like portion brake ca l.4 101 support 102 brake disc 103 brake pad 104 support plate 103 friction material 106 recess 107 ear corner 108 support prat iberance 109 caliper body Siostin.q element cyuTclLng ear 112 ear side edge ill? rear ear surface 114 front ear surface ear.recess 116 radial edge portion 117 (..ircurafeLential edge portion P.-A axial direction a-R. radial direction C-C cil-curfferenflaA or tangential direction "V;

Claims

CIAIMS1. A. cad-holding spring and pad return spring assembly (1) for a brake calliper (100), said brake caliper (100) comprising a caliper body. (10"9) adapted to be arranged -,:traddThug a disc brake (102), whereinse id ass idly (1) defillec, an axial dire (A-A), a radial direction (R---R) perpendicular to said axial direction (A-A) and a circumferential or tanoential direction (C-C) perpendicular to both said axial direction and said radial direction (R-R), said assembly comprising: -at least. pad-holding-spring (2) configured to be arranged between at. least one guiding ear (111) of a brake cad (103) housed in said caliper body (109) and said caliper body (109) so as to bias said brake cad (103) in radial. direction (R-R) and circumferential direction (C-C) and lb -a pad return spring-(3) configured to bias said bra] pad..J3) in the axial direction (A-A.) away from a brake disc ( 02), wherein. said pad-holding spring (2) and said pad return spring. (3) are made as separate pieces and are operatively connected, wherein said pad-holding spring (2) has a prevailing extension in 20- radial (R---P (and cHm-cumfereni-Hal (C --C) direct: ic-,ns and camp-rises at -a C-shaped section (4) cc-:uprising a central portion (5) which extends at least in a rad-lal direction (B-B) from which an upper portion (6) and a lower portion Cfl extend from its radially opposite ends, whereIn saidupper portion (6) and said lower portion (7) develop at lea-vr partially in a circumferential ilrenlion (C-C) "?-3 away from said central portion (5), wnerein said C-shape(1 secu±on is adapted to be inserted in (106) of sajd caliper body (109) and adapted to accomLaodate saij dt;dHnd ear (111), wherein said pad return spring (3) comprises: - an anchoring portion (8) operatively connected to said C -shaped section (4), - a coupling porLio (10) co figured Lo couple said brake pad (10 and - a I muan arm. (9) operatively connected to said anchoring-par tion (8) and to said Dp...pJing portion. (10) wherein said coupling portion (10) is elastically movable relative to said anchoring portion (8) in the direction. (.7\-1Q between a retracted resti q position and at least one advanced position, towards said disc (102), and vice versa, 1.5 wherein. said pad return spring (3) is trade from at least one wire, said pad return spring. (3) comprises at least one winding portion (17) ronnectinri said linking arm (9) to said anchoring portion (8), wherein said at least one winding portion (17) compri.ses said at least one wire, wound as a spiral about a winding axis (A) so to constantly bias said coupling portion (10) elastically at least along said axial direction (A-A) towards said retracted resting position.
9. A. cad--holding spring and pad. return spring assembly (1) according to claim 1, wherein said winding portion (17) comprises a plurality of coils (31, 32) wound around said winding axis (A), wherein the plurality of coils (31, 32) elastically deforms by torsion thus biasing said coupling portion (10) elastically towards said retracted resting position, preventing erastac deformation by bending in the axial direction (A-A) in the linking arm (9) and/or in the coupling portion (10), and/or wherein said at least one w:nding orpfl.ion (17) constantly elastically biases, along said axial direction UP said coupling portion (10) towards said retracted resting position by avoiding the contact of said brake pad (103) and/or said pad-holding spring (2) with said winding portion (17); and/or wherein said winding axic, (k) is oriented substanti parallel to the axial direction (A-or is incident and/or perpendicular to the asjil direction (A-A) or a direction parallel to it.
3. A pad-holil _ spring and. pan return sprcn sserrLbly YU acco.rding to claim 2, wherein said plurality of coils 32) comprising at least onc first. coil_ (31) and one second coil (32), and/or wherein said plurality of coils 32) are concentric forming a cylindrical or conical helical portion of the spring, and/or wherein s:flc., at leash one wire has a wire diameter, wlh..e:rein said windina nortion (17) has a. winding pitcn con-prised between. said wire diameter and 4/3 of the wire diameter.
4. A pad-holding spring and pad return spring assembly. ( ) according to claim 1, wherein. said winding po_tion (17) defines a first pad return spring axial envelope (Al), wherein said linking arm. (9) and said coupling portion (8) define a second pad return spring axial envelope wherein sam frIrc,.i-pad return spring axial envelope (Al) is less than the second axial pad return soring envelope (Al), and/or wherein said winding portion (17) defines a. first pad return 10 spring radial envelope (R1), wherein said coupling. portion (5) define.s a second pad return spring radial envelope (R2), wherein said pad return spring arial envelope UU. is smaller than the second pad return spring axial envelope (R2), 1.5 and/or where-1n said windino portion (17) is bent in winding relative to said wincPng axis (A) according to a winding direction, wherein said conplinri portion (JO) is bent at east partially in ection opposite to the winding)n.zu 5 A pad-holdingspring and pad return spring assembly (1) according to claim 1, wherein said linkj:nc comprises an arm end portion (16) tctly corm. to said counlmno nortmon (8) wherein. said arm end portion (:56) arranged at a first distance (D1.) along said circuriferential direction (C-C) relative to said central portion. . or a radial extension thereof, "?6,-Wherein said coupling portion (10) comprises a first stretch (22), which is arranged at a. second distance along said circumferential direction (C C) from said cerftni_ portion (5), wherein said second distance 02) is less than said first distance (DI) so that in the event of circumferential sliding of the coupling portion (10) relative to the brake pad (103) towards said central portion (';), said first stretch (22) interferes with said central ocrtion (5) preventing said end arm portion (16) from contacting said central portion (5).6. It pad-holding spring and pad return spring assembly (1) according to the preceding claim 5, comprising one cr more of the following features: wherein said first stretch. (22) has a. spring free end (23), wherein.1.5 said spring free end is adapted to face said central portion (5), wherein said spring free end (23) is defined by a surface equal to a. section of the spring wire, wherein said spring free end (23) is con.f:qurec to interfere with said central portion (5), preventinq the linking arm (-)and/or other portions of the coupling portion (10) from contacting the central portion (5); and/or wherein said coupling portion (10) comprises a second stretch (24), wherein said. sec)nd. stretch (24) and said first stretch (22) are connected forming a. coupling portion anale, wherein said coupling 25 portion angle is an acute annie lacing the centxal. portion. (5) 7. A pad-holding spring and pad return spring assembly. (1) according to the preceoing claim 6, comprising one more of the following features: wherein said second stretch (21) and said first stretch (22) are connected forming a concave portion in which said concave portion faces the central portion (5), wherein the second stretch (24) and the first strebch (22) are arranged or lie on the same coupling portipn plane, wherein said coupling portion plane is perpendicular to said axial direction and/or wherein c!aid first stretch (22) is a qtri.ciht win, stretch, wherein said second Htret,:h. (24) isa straHyht wire stretch, wherein said second stretch. (24) and sa-id ii. rs tstretch. (22) are connected by a third stretch. (25), wherein said third stretch (25) is curved; and/or wherein said second stretch (24) is connected tr-. said arni end portion. (16), substantially forming a right angle, wherein said second stretch. (24) is inclined in the coupling plane 20 portion by a second stretch angle comprised between. 0 and 45 degrees relative to said radial direction (h--RI, preferably between 15 and 30 degrees, 8. A. pad-hcading spring and pad return spring assembly (1) according 25 to claim. I, wherein said anchoring portion (8) has at That-a first straight stretch (19), which extends away from the brake disc (102), "?i,3 wherein said first straioht stretch (19) is parallel to the axial direction (A.-A), wherein said anchoring portion has at least a curved first stretch (18) which connects said winding portion to said straight first stxtL,....h (19) to as to arrange the winding a of the wining portion (17) either parallel or incident and/or perpendicular to the axial direction (A-A), wherein winding portion (17) extends in a helical manner in the direction of said brake disc (102), and ',therein said linking arm (9) is substantially straight and parallel to said axial. direct (A-A), wherein said linking arm (9) is connected to said w.irLd.inc cort.ic1 (17) by means of a. rirst curved connection (33) that forms a right:-.no le with said winding p.o ction (17) in a. plane comprising at least said axial direction (A-A) so as to arrange said inking arm (9) parallel to said axial direction (A-A).9. ilbirakepac). assembly for a. brake caliper (100), comprising at least one brake pad (103) and at least one pad--holding spring and pad return spring assembly (1) arflording to any one of the preceding claims, wherein said pad-holding spring and pad return spring assembly (1) is connectable to said brake pad (102.), wherein. sad brake pad. (103) comp 'iction material. (105) and a. support plate (101) supporting said friction material (105), 25 wherein. said support plate (104) comprises at least one guiding ear (ill) protruding laterally in a circumferential direction. (0-C), "?9 wherein said C-shaped section (4) of said pad-holding spring (2) is cacti ured to accommodate said guiding ear (111) so as to bias said pad Lel' in a circumferential direction (C-C) and a radial direction (a wherein said coupling portion (10) of said pad return spring (?) is configtLred to engage said guiding ear (111) so as to bias said pad (103) in a direction from a brake disc (1) by. means of said winding portion (17) distanced by at least said linking arm from said coupling. portion (le), and by preventing the uncoupling of said coupling portion (10) from said brake pad (103).10. A brake calir (100) comprising a caliper body 109) connectable to a vehicle and adapted to be arranged straddling a brake disc (102), wherein said caliper body 1.5 (109) comprises at least one brake pad housing pocket, wherein said housing pocket comprises at least one recess ( ii pad assembly according to claim 9, wherein said pad-l spririg (2) interposed at least.. between said guiding-ear (111) and said recess (106), -wherein said coupling port n of said pad return spring (3) is coupled-with said guiding ear (111) to bias it in a direction away from, said brake disc (102).