Patent ID: 12253132

DESCRIPTION OF SOME PREFERRED EMBODIMENTS

According to a general embodiment, a caliper body1for a brake caliper2for disc brake3is provided.

In a disc brake3an axial direction X-X is defined either coinciding with or parallel to the rotation axis A-A—of the disc4of the disc brake3, a brake disc radial direction R-R orthogonal to the axial direction X-X, and a tangential direction T-T, orthogonal to both the axial direction X-X and to the brake disc radial direction R-R.

The axial direction X-X defines an inner axial direction XI, directed towards the disc4, and an outer axial direction XO, opposite with respect to said inner axial direction XI.

Said caliper body1is adapted to straddle the disc4.

Said caliper body1comprises a first elongated portion5adapted to face, either directly or indirectly through the interposition of at least one brake pad11, a first braking surface6of the disc4, and a second elongated portion7, opposite to said first elongated portion5and adapted to face, either directly or indirectly through the interposition of at least one brake pad11, a second braking surface8of the disc4opposed to said first braking surface6.

Said caliper body1further comprises at least one caliper bridge9to connect said first elongated portion5and said second elongated portion7to each other arranged straddling the disc4.

At least either said elongated portion5or said second elongated portion7comprises at least one thrust device housing10, or cylinder10, adapted to receive at least one portion of a thrust device13or piston13, adapted to apply a thrust action14directed in inner axial direction XI on at least one facing brake pad11to abut said at least one facing brake pad11against a braking surface6,8of the disc4.

Said at least one thrust device housing10extends about a thrust axis a-a, parallel to the axial direction X-X, and defines a radial thrust direction r-r orthogonal to said thrust axis a-a and incident thereto. Said radial direction r-r defines an outer radial direction rI directed towards said thrust axis a-a and an outer radial direction rO, opposite to said inner radial direction rI. A circumferential direction of thrust device c-c, orthogonal to said thrust axis a-a, and said radial direction r-r, is also defined.

According to a preferred embodiment, at least either said elongated portion5and said second elongated portion7comprises a first annular housing15which radially opens into said thrust device housing10.

According to a preferred embodiment, said first annular housing15is adapted to receive an elastic retraction element30or elastic roll-back element30, adapted to apply a retracting action in outer axial direction XO on said thrust device13.

According to an embodiment, said first annular housing15is delimited at least partially in outer radial direction rO by a first bottom wall16.

According to a preferred embodiment, said first annular housing15is delimited at least partially in inner axial direction XI by a second axial wall17.

According to a preferred embodiment, said first annular housing15is delimited at least partially in outer axial direction XO by a third axial wall18.

According to a preferred embodiment, at least either said first elongated portion5and said second elongated portion7further comprises a second annular housing20which radially opens into said first annular15.

According to a preferred embodiment, said second annular chamber20is delimited in radial outer direction rO by a chamber bottom arched wall19having a chamber bottom arched wall concavity R19facing in radial inner direction rI which joins in an axial inner portion thereof to said second axial wall17and in an axial outer portion thereof to said first bottom wall16of said first annular housing15.

In this manner, said second annular chamber20is adapted to receive at least a portion of said elastic retraction element30at least when said thrust device13applies the thrust action14.

According to a preferred embodiment, said chamber arched bottom wall19has a substantially constant radius of curvature.

According to a preferred embodiment, said first bottom wall16of the first annular housing15extends substantially along a straight line.

According to a preferred embodiment, said first bottom wall16of the first annular housing15is tapered in the outer axial direction XO, in other words away from the disc4. Preferably, said first bottom wall16of the first annular housing15tapers in outer axial direction XO, forming a first bottom wall angle γ comprised between 6° and 8°, and preferably equal to 7°15′.

According to an embodiment, the chamber bottom arched wall19sweeps an arched wall angle α between 170° and 220°. Preferably, said arched wall angle α is comprised between 175° and 200°. According to a preferred embodiment, said arched wall angle α is substantially equal to 180°. According to an embodiment, said arched wall angle α is evaluated on a plane parallel to the axial direction X-X and the radial thrust direction r-r.

According to an embodiment, said chamber bottom arched wall19joins the first bottom wall16by means of a first connection22having first connection concavity R22opposite with respect to said bottom wall chamber concavity R19. According to an embodiment, said concavity of first connection R22is directed in outer radial direction rO.

According to an embodiment, said first connection wall22sweeps a first connection wall angle δ comprised between 96° and 98°, and preferably substantially equal to 97°15′.

According to an embodiment, said second axial wall (17) extends substantially in thrust device radial direction r-r, preferably tapering in the outer radial direction rO by effect of the draft angles.

Preferably, said caliper body1is made of metal using foundry techniques, e.g. sand casting or shell casting. According to an embodiment, said caliper body1is made in one piece, e.g. with a single casting.

According to an embodiment, said second axial wall17joins said chamber bottom arched wall19in thrust device radial direction r-r.

According to an embodiment, said thrust device housing10is delimited at least partially in outer radial direction rO by at least one thrust device housing wall23.

According to an embodiment, said thrust device housing wall23joins to said second axial wall17by means of an inner axial stretch24parallel neither to the thrust device radial direction r-r nor to the axial direction X-X.

According to an embodiment, said inner axial stretch24forms an inner axial stretch angle β comprised between 54° and 56° with said second inner axial wall17. Preferably, said inner axial stretch angle β is substantially equal to 55°.

According to an embodiment, said inner axial stretch24forms an inner axial stretch angle β comprised between 54° and 56°, and preferably substantially equal to 55° with the thrust device radial direction r-r.

According to an embodiment, said thrust device housing wall23joins to said third axial wall18by means of an inner axial stretch25parallel neither to the thrust device radial direction r-r nor to the axial direction X-X.

According to an embodiment, said outer axial stretch25forms an angle comprised between 44° and 46°, and preferably substantially equal to 45° with the thrust device radial direction r-r.

According to an embodiment, said thrust device housing10is delimited in outer axial direction XO by a housing back wall29.

According to an embodiment, said thrust device housing10is substantially cup-shaped.

According to an embodiment, said third axial wall18joins to said first bottom wall16by means of a radial stretch26inclined and parallel neither to the radial direction r-r nor to the axial direction X-X. Preferably, said radial stretch26forms an angle comprised between 44° and 46°, and preferably substantially equal to 45° with the thrust device radial direction r-r.

According to a preferred embodiment, said second axial wall17of the first annular housing15joins to said thrust device housing wall23by means of an inner axial stretch24which forms an inner axial stretch angle β with the thrust device radial direction r-r, to form an axially inner deformation chamber37for said elastic retraction element30.

According to a preferred embodiment, said inner axial deformation chamber37has a wedge-shaped section of a tapering in inner axial direction XI.

According to a preferred embodiment, said inner axial stretch24comprises an arched stretch36having an inner arched axial stretch concavity R36facing radial outer direction rO.

The provision of said arched section36adapted to abut against an axially inner face of the elastic retraction element30makes it possible to reduce the amount of the strains arising on the body of the retraction device30during the thrust action14.

According to a preferred embodiment, said inner axial stretch angle β is comprised between 55° and 75°.

According to an embodiment, e.g. shown inFIG.12, said inner axial stretch angle β is substantially equal to 60°.

According to an embodiment, e.g. shown inFIG.16, said inner axial stretch angle β is substantially equal to 70°.

According to a preferred embodiment, said arched stretch36connects said inner axial stretch24with said second axial wall17.

According to an embodiment, the radius of curvature of said arched stretch36is comprised between 0.25 and 1.30.

According to an embodiment, e.g. shown inFIG.12, the radius of curvature of said arched stretch portion36is substantially equal to 0.30.

According to an embodiment, e.g. shown inFIG.14, the radius of curvature of said arched stretch portion36is substantially equal to 1.25.

According to an embodiment, said first bottom wall16connects to said second axial wall17by means of an outer radial connection38. According to an embodiment, said outer radial connection38has a radius of curvature comprised between 0.2 and 0.3, and preferably substantially equal to 0.25.

According to an embodiment, a brake caliper2comprises a caliper body1according to any of the embodiments described above.

According to a preferred embodiment, said brake caliper2further comprises at least one pair of brake pads11, each brake pad11comprising friction material34, adapted to press against a facing braking surface6or8of the disc4, and a support plate33which supports said friction material34.

According to a preferred embodiment, said brake caliper2further comprises at least one thrust device13received in said at least one thrust device housing10so that it can slide axially with respect to said thrust device housing10.

The thrust axis a-a, parallel to the axial direction X-X, the radial thrust direction r-r orthogonal to said thrust axis a-a and incident to it, and the inner radial direction rI directed towards said thrust axis a-a, outer radial direction rO, opposite to said inner radial rI direction, and the circumferential direction of thrust device c-c, are understood to be also defined on said thrust device13when at least partially accommodated in said thrust device housing10.

According to a preferred embodiment, said support plate33comprises a back plate35or pad back35facing opposite with respect to the friction material34and adapted to face such a thrust device13.

According to a preferred embodiment, said thrust device13further comprises a thrust surface32, adapted to abut against said back plate35of said brake pad11, to apply the thrust action14.

According to a preferred embodiment, at least said one thrust device13is in form of a piston having substantially cylindrical geometry which extends about the thrust axis a-a.

According to a preferred embodiment, at least one thrust device13, comprises an outer wall or skirt28directed in axial direction X-X. Preferably, said skirt28is also directed in the thrust device circumferential direction c-c.

According to a preferred embodiment, said skirt28of the thrust device13cooperates with said thrust housing wall23of the thrust device housing10to guide the movement in axial direction X-X of the thrust device13with respect to the caliper body1. In this manner, said thrust action14is applied.

According to an embodiment, said brake caliper2further comprises at least one elastic retraction element30. According to a preferred embodiment, said at least one elastic retraction element30has an annular shape and is received in said first annular housing15.

In operating conditions during the thrust action14, said at least one elastic retraction element30deforms elastically as a result of the inner axial direction XI applied by thrust device13towards the disc4. When the thrust action14ceases, the elastic retraction element30applies a retracting action on said thrust device13, moving it away from the plate back35by an axial luft distance31.

According to a preferred embodiment, said brake caliper2further comprises at least one axial spring21adapted to bias at least one brake pad11away from the disc when the retracting action ceases, in other words when the braking action ceases. In this manner, the axial spring21carries said plate back35against said thrust surface32of the thrust device13.

Fixing means of the vehicle12, e.g. threaded, may be provided on said caliper body1, e.g. on said second extended portion7.

By virtue of the provision of said deformation chamber37, according to an embodiment, the body of the retraction device30, during the thrust action14, deforms elastically in the inner axial direction XI in contact with the skirt28of the thrust device13.

By virtue of the provision of said at least a second chamber20, according to a preferred embodiment, the body of the retraction device30, during the thrust action14, deforms elastically occupying said second chamber20, thus reducing its axial deformation in said chamber37, which can, therefore, be made smaller the retracting action being equal, compared to known solutions.

By virtue of the suggested solutions, it is possible to reduce the variability of the axial distance of luft31, even in prolonged use.

By virtue of suggested solutions, it is possible to reduce the wear of the elastic retraction element30by extending its service life.

According to a general embodiment, a disc brake3comprises at least one brake caliper1according to any one of the embodiments described above.

According to a preferred embodiment, said disc brake3comprises at least one disc brake disc4.

The person skilled in the art may make many changes and adaptations to the embodiments described above or may replace elements with others which are functionally equivalent to satisfy contingent needs without however departing from the scope of the appended claims.

LIST OF REFERENCES

1Caliper body2Brake caliper3Disc brake4Disc brake disc5First elongated portion of the caliper body6First braking surface of the disc7Second elongated portion of the caliper body8Second braking surface of the disc9Caliper bridge10Thrust device housing or cylinder11Brake pad12Fixing means to the vehicle13Thrust device or piston14Thrust action15First ring housing16First bottom wall of the first annular housing17Second axial wall of the first annular housing18Third axial wall of the first annular housing19Chamber bottom arched wall20Second annular chamber21Axial spring of the brake caliper22First connection, or connection23Thrust device housing wall24Inner axial stretch25Outer axial stretch26Inclined radial stretch27Dust cuff28Thrust device skirt29Housing bottom wall30Elastic retraction element31Axial luft distance, or luft32Piston thrust surface33Brake pad supporting plate34Brake pad friction material35Brake pad back, or plate back36Arched connection stretch37Deformation chamber38Outer radial connectionα Arched wall angleβ Inner axial stretch angleγ First back wall angleδ First connection wall angleR19Chamber bottom arched wall concavityR22First connection concavityR36Arched axial stretch concavityA-A Disc rotation axisX-X Disc brake axial directionXI Inner axial directionXO Outer axial directionR-R Disc brake radial directionT-T Disc brake tangential directiona-a Thrust axisr-r Radial direction, or thrust device radial directionrI Inner radial directionrO Outer radial directionc-c Thrust device circumferential direction