CALIPER BODY

The present invention refers to a caliper body for a disc brake, for example for a motor vehicle, as well as to a caliper for a disc brake that comprises such a body.

In particular, in a disc brake, the brake caliper is arranged straddling the outer peripheral edge of a disc brake. The brake caliper usually comprises a body having two elongated elements that are arranged so as to face opposite braking surfaces of the disc. Friction pads are foreseen arranged between each elongated element of the caliper and the braking surfaces of the brake disc. At least one of the elongated elements of the body of the caliper has cylinders suitable for receiving hydraulic pistons capable of exerting a thrusting action on the pads abutting them against the braking surfaces of the disc to exert a braking action on the vehicle.

The brake calipers are usually fixedly connected to a support structure that stays still with respect to the disc, like for example the forks of a motorcycle or a support fixedly connected to the forks of the motorcycle.

In a typical arrangement, one of the two elongated elements has two or more attachment portions of the body of the caliper re the support structure, for example foreseeing slots or eyelets, for example arranged axially, or through holes, for example arranged radially, suitable for receiving screws for fixing the caliper that, with their ends are received in threaded holes foreseen on the support of the caliper.

In a typical caliper body construction, the elongated elements arranged facing the braking surfaces of the disco are connected together by bridge elements arranged straddling the disc.

The caliper comprises different components mounted on the body such as the pistons, gaskets, drainage devices and brake fluid supply ducts.

Typically, the body of the caliper is made from metal like for example aluminium, aluminium alloy or steel. The body of the caliper can be obtained by fusion, but also by mechanical processing with chip removal, as well as by forging.

The body of the caliper can be produced either in a single piece or in a monoblock, but also in two half-calipers typically connected together along a plane that usually coincides with the middle plane of the disc on which the caliper is arranged to straddle. In the case in which the driver of the vehicle wishes to brake or slow down the movement of the vehicle, he applies a pressure on the brake pedal, in the case of an automobile, or on the brake lever, in the case of a motorcycle. Such pressure en the brake lever, by means of a brake pump, exerts a pressure in the brake fluid that through a duct is applied to the brake fluid present in the hydraulic circuit placed inside the body of the caliper until it reaches the cylinders where the pressure is exerted on the surface of the bottom of the pistons forcing them to lock against the pads, which in turn abut against the braking surfaces of the disc. The pressure action of the brake fluid is also exerted on the bottom wail of the cylinder determining a reaction in the body of the caliper that deforms it away from the surfaces of the disc. This deformation of the body of the caliper leads to an increase in the^ stroke of the pistons and thus, to an increase of the stroke of the brake lever.

The body of the caliper must therefore have sufficient structural rigidity, so as to ensure that this deformation of the body of the caliper caused by the braking action is kept within tolerable values, which, as well as avoiding damage to the braking system, do not create the sensation for the driver of an unresponsive braking system, determining an extra stroke of the brake lever (creating a "spongy" sensation) . This need pushes towards having extremely rigid structures for the bodies of the calipers and therefore increasing their bulk and weight.

On the other hand, the body of the caliper, being fixedly connected to the suspension of the vehicle and being arranged straddling the disc, is one of the unsuspended masses that it is wished to reduce as much as possible to increase the performance of the vehicle.

Of course, these considerations are taken to the extreme when the vehicle is a racing vehicle and the user wishes to have a braking system that is extremely responsive to his commands and at the same time extremely light so as not to penalise the performance of the racing vehicle.

Therefore, there is a need for a caliper body for a disc brake, which has improved structural characteristics for the same weight of the body of the caliper, or else with the same structural characteristics for a lower weight compared to solutions of the prior art.

Solutions for caliper bodies are known that have been specially studied to increase the characteristics of structural rigiαity. For example, parent application EP-A-2022999, patent application EP-A- 1534974, patent US-6708802, patent application EP-A- 1911989, patent application PCT/EP2005/050615, patent application JP-A-09257C63 and patent US 3 183 999 present solutions of bodies for brake calipers equipped with reinforcing elements arranged around caliper bodies. In some of these known solutions, the caliper body is symmetrical according to planes passing through the axis of the disc or through the middle of the disc. In other solutions the caliper body has large and distributed windows even passing straight through that form elongated reinforcement elements arranged longitudinally to the body of the caliper.

Although satisfactory from many points of view, these known solutions nevertheless do not allow structures to be obtained that maximise the structural rigidity of the body of the caliper reducing the weight and at the same time reduce the bulk as much as possible so as to facilitate the assembly of the body of the caliper even inside wheel rims on which brake discs having a large diameter are mounted.

These and further purposes are accomplished through a caliper body as described in claim 1 attached hereto.

Further purposes, solutions and advantages are present in the embodiments described hereafter and claimed in the dependent claims attached hereto.

Different embodiments of the invention are now described hereafter through examples given only as examples and not for limiting purposes, with reference in particular to the attached figures, in which:

- figure 1 shows an axonometric view from above

- support side disc outlet flank of a caliper body of a disc brake;

- figure 2 illustrates an axonometric view from above - support side disc inlet flank of the caliper body of figure 1;

- figure 3 shows an axonometric view from above

- opposite side to the disc inlet flank support of the caliper body of figure 1 ;

- figure 4 shows an axonometric view from above

- opposite side to the disc outlet flank support of the caliper body of figure 1;

- figure 5 shows an axonometric view from below

- support side disc inlet flank of the caliper body of figure 1;

- figure 6 illustrates an axonometric view from below - support side disc outlet flank of the caliper body of figure 1;

- figure 7 shows an axonometric view from below

- opposite side to the disc inlet flank support ofthe caliper body of figure 1;

- figure 8 shows an axonometric view from below

- opposite side to the disc outlet flank support of the caliper body of figure 1; figure 9 illustrates a front view of the caliper body of the disc brake of figure 1; figure 10 shows a view from above of the caliper body of the disc brake of figure 1;

- figure 11 illustrates a view from below of the caliper body of the disc brake of figure 1;

- figure 12 shows a disc inlet side view of the caliper body of the disc brake of figure 1;

- figure 13 illustrates a view from the back of the caliper body of the disc brake of figure 1;

- figure 14 shows a disc outlet side view of the caliper body of the disc brake of figure 1; figure 15 illustrates a front view of the caliper body of the disc brake of figure 1 indicating the section line XVl - XVl;

- figure 16 illustrates the section according to the line XVI - XVI of the caliper body of figure ^' 15;

- figure 17 shows a disc inlet side view of the caliper body of the disc brake of figure 1 indicating the section line XVITI - XVIIT;

- figure 18 illustrates the section according to the line XVIII - XVIII of the caliper body of figure 17;

- figure 19 shows a disc inlet side view of the caliper body of the disc brake of figure 1 indicating the section line XX - XX;

- figure 20 illustrates the section according to the line XX - XX of the caliper body ot figure 19;

- figure 21 shows a disc inlet side view of the caliper body of the disc brake of figure 1 indicating the section line XXIΪ - XXII;

- figure 22 illustrates the section according to the line XXII - XXTI of the caliper body of figure 21; figure 23 shows a view from above of the caliper body of the disc brake of figure 1 indicating the section line XXVI - XXVI;

- figure 24 illustrates the section according to the line XXVl - XXVI of the caliper body of figure 23

- figure 25 illustrates a perspective view from the disc inlet side in a caliper body according to a further embodiment, in which the elongated portions are connected by a central bridge having an non- attachment side outer portion undercut or lowered;

- figure 26 illustrates a perspective view from the disc outlet, side of the caliper body of figure

7 ^ •

- figure 27 illustrates a side view from the disc outlet side of the caliper body of figure 25.

Hereafter we shall describe an embodiment of a caliper body of a disc brake.

3y the term "axial direction" we mean a direction parallel to the axis of the brake disc that cooperates with the brake caliper comprising the caliper body arranged straddling such a brake disc.

By the term "tangential direction" we mean a direction parallel to one of the braking surfaces of the brake . disc on which the caliper is arranged straddling it and perpendicular to the axial direction and tangent to any circumference, with centre on the rotation axis of the disc.

By the term "radial direction" we mean a direction perpendicular to the axial direction and to the tangential direction.

A disc for a disc brake, in figure 1 indicated with reference numeral 40, has a rotation axis that defines an axial direction A-A, as well as a tangential direction T- T or circumferential direction C-C that is parallel to one of its braking surfaces 41, 42. In particular, the tangential direction T-T or circumferential direction C-C with respect to the body of the caliper 1 has two senses that can be defined "disc inlet" and "disc outlet" as a function of the rotation (indicated with the reference arrow 45 in figure 1) of the disc 40 with respect to the caliper body 1 that is arranged straddling said disc 40. The disc inlet sense is the sense of the tangential direction T-T that watches the disc approach during its rotation (rotation that in figures 1 and 10 is indicated with the arrow 45} . The disc outlet sense is the sense of the tangential direction T-T that watches the disc move away during its rotation. With "disc inlet" portions or surfaces or parts we refer to all those portions of the caliper that face towards the tangential or circumferential direction that sees the disc approach during its rotation around the axis A-A. Said tangential or circumferential direction T-T also hasa further opposite sense that defines for the portions of the caliper the disc outlet portions or parts or components or surfaces, with such a term defining all the portions of the caliper that see the disc come out from the body of the caliper arranged straddling the disc when it rotates around its rotation axis A-A. Such a tangential direction T-T has an arrangement that is perpendicular with respect to the axial direction A-A and is tangent to any of the circuπferences with centre on the rotation axis of the disc. The disc 40 also defines a further direction perpendicular to the axial direction A-A and tangential direction T-T, which is the radial direction R-R. Also for the radial direction R-R it is possible to define "outer" portions, parts, components and surfaces that define all the portions of the body of the caliper that are oriented towards the opposite side of the rotation axis of the disc A- A, as well as "inner" portions, parts, component and surfaces that define ail the portions of the caliper that face towards or are oriented towards the rotation axis of the disc A-A (see for example figure D •

Relative to the arrangement of the body of the caliper 1 with respect to the disc 40 and to the suspension of the vehicle, it is also possible to define an attachment side, portions and surfaces that define all the portions of the caliper that face the support foreseen on the spindle of the vehicle or on the support connected to the forks of the motorcycle that, as well as facing support means of the caliper that are fixed with respect to the disc, also faces a first braking surface 41 of the disc facing towards the vehicle. It is also possible to define an opposite side of the body of the caliper 1 that defines portions or surfaces that are opposite to the support means of the caliper and thus to the vehicle that can be defined as non-attachment portions to the vehicle and with this defining all of the portions of the caliper that, with their surfaces face the opposite braking surface 42 of the disc for the disc brake and connect to the vehicle through bridge portions arranged straddling the disc.

As can also be seen from figure 10 depicting a view from above of a body of the caliper 1 arranged straddling a disc 40, it is possible to define a middle axis M-M arranged on the middle plane of the disc 40 to divide substantially the body of the caliper into two sections 200 and 202 in the axial direction of equal extension (the distance 203 - 201 and 201 - 204 is _, substantially equal) . The intersection between the projection of the rotation axis A-A of the .disc and the middle plane M-M of the disc 40 defines a centre of the caliper 23. In this view it is also possible to define two further axes parallel to the rotation axis A-A of the disc and arranged according to the axial direction: a first of these axes Ai-Al is arranged parallel to the rotation axis A-A of the disc and is tangent to the outer profile of the body of the caliper and defines the tangential end of the disc inlet flank 43. In this figure it is also possible to define a further axis A2-A2 that is arranged at the tangential end of the disc outlet flank 44. In other words, in a view from above, as depicted in figure 10, it is possible to see the entire body of the caliper located between two axes parallel to the rotation axis of the disc, i.e. the axes Al-Al and A2-A2.

Therefore, said disc 40 defines an axial direction A-A that is parallel to a rotation axis thereof, as well as a tangential direction T-T or circumferential direction C-C parallel to one of the braking surfaces of the disc 41, 42 as well as a disc input, direction, indicated with the reference "IN", and a disc, output direction, indicated with the reference "OUT" (with reference to the rotation of the disco given by the arrow 45 in figure 1 and in figure 10) , and also a radial direction R-R perpendicular to the axial direction A-A and to the tangential direction T-T, the latter defining an outer radial sense (Indicated with the reference arrow RE for example in figure 12) facing away from the rotation axis of the disc.

In accordance with a general embodiment, a caliper body 1 for a disc- brake comprises an elongated attachment side portion 2 that is suitable for facing towards a first braking surface 41 of a disc 40.

Again in accordance with a general embodiment of the invention, said elongated attachment side portion 2 comprises at least two attachment portions 7, 8 suitable for coupling the body of the caliper 1 with a support thereof, not depicted.

In accordance with an embodiment, said attachment portions 7, 8 comprise an attachment portion 7 facing the disc inlet side of the body of the caliper 1, marked in figure 1 with the reference ^Vλ IN", and an attachment portion 8 arranged at the end of the disc outlet side of the body of the caliper 1, indicated in figure 1 with the reference "OUT". ^•

In accordance with an embodiment, said attachment portions 7, 8 can consist of portions that project cantilevered from the body of the caliper 1 towards the axis of the disc to define eyelets for an axial coupling with the support of the body of the ca l iper .

In accordance with a further embodiment, preferably the attachment portions 7, 8 comprise through holes 46, 47 defined for example by cylindrical portions 48, 49 foreseen in the elongated attachment side portion 2 of the body of the caliper 1. Such cylindrical portions 48, 49, advantageously have undercut portions 50, 51 and ribs 52 suitable for strengthening said attachment portions 7, 8 and at the same time for lightening them reducing their rr.ass .

In accordance with a general embodiment, said caliper body 1 also comprises an elongated non- attachment side portion 3 suitable for facing the second braking surface 42 opposite the first braking surface 41 of the disc 40.

In accordance with an embodiment, each elongated portion 2, 3 houses at least one cylinder 9; 10; 11; 12 suitable for receiving a piston for exerting a pressure on pads that can be housed between said elongated portions 2, 3 of the caliper 1 and said braking surfaces 41, 42 of the disc 40.

In accordance with an embodiment, said caliper body 1 also comprises at least one connection bridge 4; 5; 6 arranged straddling the disc 40 connecting the elongated attachment side portion 2 with the elongated non-attachment side portion 3.

Advantageously, as car. be seer, particularly well in figures 12 or 14 or 16 or 17 or 19 or 21, said elongated portions 2, 3 have an outer surface 13, 14 arranged, with respect to the disc 40, outside of the body ot the caliper 1 or on the side opposite the disc, said outer surface 13, 14 being substantially inclined (in figure 12 for example two directions Till and 12-12 are highlighted that show the inclination of the outer surfaces 13, 14) and also, passing in the radial direction R-R from the radially inward way to the radially outward way, rounded towards the disc 40 (where the radially outward way is indicated in figure 12 with the reference arrow "RE"), so that the body of the caliper 1, observed in the circumferential direction C-C or tangential direction T-T, or in other words observed from a flank thereof (for example that of figure 12 is the disc inlet flank), has a bulk with a rounded outer surface like a tortoise shell.

In accordance with an embodiment, the body of the caliper comprises two end bridges 4, 5 connecting the elongated attachment side portion 2 with the elongated non-attachment side portion 3 arranged near to the tangential or circumferential ends or disc inlet and disc outlet ends of the elongated portions.

In accordance with an embodiment, the body of the caliper comprises a third central bridge 6 connecting the elongated attachment side portion 2 with the elongated non-attachment side portion 3, wherein said central bridge 6 is arranged substantially connecting the middles of these elongated portions 2, 3.-

In accordance with a further embodiment, said caliper body 1, when seen from above or according to the radial direction looking towards the axis of the disc, for example as depicted in figure 10, has . the end bridges 4, 5 having an outer profile, i.e. a surface facing the disc inlet or the disc outlet, which tapers or curves in passing from the _elongated attachment side portion 2 to the elongated non- attachment side portion 3.

In accordance with a further embodiment, said end bridges 4, 5 have an outer profile, i.e. facing the disc inlet or disc outlet, which extends when they move away from the attachment portions 7, 8 rounding towards the centre of the caliper 23 or in other words they round or curve around the centre of the caliper 23 for their curved extension 15, 16 that in at least one bridge 7 is more than half its overall extension in the axial direction.

For example, in the embodiment depicted in figure 10 the disc inlet end bridge 4 has an outer surface that, in its section from the disc inlet flank tangential end 43 to the attachment 53 to the elongated non-attachment side portion 3, has a curved profile with greater extension with respect to the overall length of the end bridge 4 (the section from reference numeral 43 to reference numeral 53 is highlighted in the figure 10 with a broken line) .

In accordance with an embodiment, the caliper body 1 viewed from above according to an inward radial direction looking towards the axis of the disc, has the end bridges 4, 5 having an outer profile that starts to taper and curve towards the centre 23 of the caliper or around the centre of the caliper 23 going from the elongated attachment portion 2 and curving in at least one of the two bridges 4 already before reaching the middle M-M of the caliper 1 in the axial direction to then reach the elongated non-attachment side portion 3.

In accordance with an embodiment viewed from above, or in the inward radial direction looking towards the axis of the disc, the body of the caliper 1 has an outer profile 17 that, with respect to its attachment portions 7, 8 in extending to form, through the bridges 4, 5, the elongated non- attachment side portion 3, forms a rounded shape, or outer profile, 18 like a tortoise shell.

Therefore, in accordance with an embodiment, the body of the caliper, both in a side view and in a view from above or below, has a curved outer profile like a tortoise shell.

For example, in accordance with an embodiment., this outer profile 17 can be seen from below where it is seen that the outer profile 17 going from the disc inlet attachment portion 7 closes rounding in a continuous manner and bevelled to the point of defining the outer surface of the elongated non- attachment side portion 3 and continuing to round off to close on the disc outlet side attachment portion 8.

In accordance with a further embodiment, this outer profile 17 can be seen from figure 11 from below where it can be seen that the outer profile 17 going from the disc inlet attachment portion 7 slightly widens to then close rounding off in a continuous manner and bevelled to the point of defining the outer surface of the elongated non- attachment side portion 3 and continuing the round off to close on tne disc outlet side attachment portion 8.

Of course, in this figure 11, the outer profile 17 is depicted on the reverse ar.ά highlighted in figure through a broken line that substantially envelops the body of the caliper 1.

In accordance with a further embodiment, the body of the caliper 1 has at least one end bridge 5, preferably the end bridge of the disc outlet side "OUT" that extends from the elongated attachment side portion 2 near to the disc outlet attachment portion 8, projecting towards the elongated non-attachment side portion 3 and remaining inside the bulk of the attachment portion 8, considering this bulk in the tangential direction T-T or circumferential direction C-C. Thanks to this characteristic, at least the attachment portion 8 is arranged at the disc outlet side tangential end 44 of the elongated attachment side portion 2 (for example, see figure 10 or figure 11) .

Tn accordance with a further embodiment, outside of the elongated shapes 2, 3 there are reinforcement ribs 19, 20. Such reinforcement ribs 19, 20 extend in the tangential or circumferential direction along said elongated portions 2, 3.

In accordance with an embodiment;, the reinforcement ribs 19, 20 taper in the axial direction and have a rounded free edge. In accordance with an embodiment, the reinforcement ribs 19, 20 are joined to the elongated portions 2, 3, for example forming concavities.

In accordance with an embodiment, the reinforcement ribs 19, 20 taper in the tangential or circumferential direction passing from the disc outlet side attachment portion 8 to the disc inlet- side attachment portion 7.

In other words, advantageously, the material of the reinforcement ribs 19, 20 is preferably placed up against the disc outlet side (OUT) with the reinforcement ribs being tapered going towards the disc inlet (IN) .

In accordance with an embodiment, the caliper body 1, in the tangential direction T-T or circumferential direction C-C, has a disc inlet end 21, 43 and an opposite disc outlet end 22, 44.

In accordance with an embodiment, the caliper body 1 viewed from above or below has an outer profile 17 that closes ^' after ■ having gradually opened in the axial direction to connect the elongated non- attachment side portion 3 forming a substantially arched profile towards the opposite attachment portion 8 arranged at the disc outlet side end 44 and avoiding extending in the tangential direction T-T or circumferential direction C-C beyond said disc outlet attachment portion 8.

In accordance with a further embodiment, ihe caliper body 1 viewed from above or below (for example figure 10 and figure 11) has an outer profile 17 that extends beyond the disc inlet side attachment portion 7 in the tangential or circumferential direction moving away for a short section from the centre of the caliper 23 (according to the arrow 60 of figure 11) towards the disc inlet "IN", to then close after having gradually opened in the axial direction to connect the elongated non-attachment side portion 3 (arrow 61) forming a substantially arched profile towards the opposite attachment portion 8 arranged at the disc outlet side end AA and avoiding extending in the tangential direction T-T or circumferential direction C-C beyond said disc outlet attachment portion 8 (arrow 62 of figure 11) .

In accordance with a further embodiment, each elongated portion 2, 3 comprises two cylinders 9, 10 or 11, 12 suitable for receiving pistons. According to an embodiment, in the body of the caliper 1 there are, on the cater surface of the elongated portions 2, 3, reinforcement ribs 10, 20 that extend from the body cf the caliper in the axial direction and also extend along the elongated portions 2, 3 in the tangential direction T-T or circumferential direction C-C to reinforce bottons 24, 2b and 26, 27 of the cylinders 9, 10; 11, 12 having substantial side recesses 28, 29 towards the centre 23 of the caliper 1 passing between one cylinder and the other.

In accordance with an embodiment, the radially inner side or surface 70, 71 (for example visible in fig. 5, 6, 7, 8, 9 and 13) of the elongated portions 2, 3 are shaped so as to follow the profile of the cylinders 9, 10 and 11, 12 forming a substantial lower recess 30, 31 in the radial direction between the cylinders arranged housed in the same elongated portion 2, 3 (see for example fig. 5) .

In accordance with an embodiment, the elongated portions 2, 3 and the bridges that connect the 4, 5 and 6 are shaped so as to leave substantial portions of the cylinders 9, 10 and 11, 12 uncovered (see for example figs. 1, 2, 3, 4, 9 and 13).

In accordance with an embodiment, the body of the caliper 1, between the bridges 4, D and 6 connecting the elongated portions 2 and 3, has upper recesses 32, 33 and 34, 35 in the elongated portions 2, 3 so as to highlight the shape of the cylinders 9, 10 and 11, 12 in the upper or radially outer surface of the body of the caliper.

In accordance with a further embodiment, the body of the caliper 1 comprises ducts 36, 37, 106, 107, 108, 100, 101, 114, 115 and 116 for distributing the brake fluid inside the caliper body 1 suitable for reaching the inner chambers defined by the cylinders 9, 10 and 11, 12 and exerting a pressure on the bottoms of the pistons to press the pads against the braking surfaces 41, 42 of the disc 40.

In accordance with an embodiment, in particular as can be seen from figure 15 and from the section represented ^' in figure 16, the body of the caliper 1 comprises bridge ducts 36, 37 for the brake fluid that are arranged inside the central bridge 6 so as to stay in the arched profile of the bridge 6 to reach, from a portion near to the centre of the caliper 23, at least one chamber defined by a cylinder 10, 11 near to a bottom 25, 27 thereof.

Thanks to the arched shape of the outer surface of the bridge 6 it is possible to make these ducts 36, 37 without significantly weakening the body 1 of ihe caliper .

In accordance with an embodiment, the body of the caliper 1 is a raonoblock body or in other words in a single piece, for example obtained by fusion or by chip removal or by forging of aluminium or aluminium alloy.

In accordance with an embodiment, inside the body of the monobiock caliper 1 ducts are made to take pressurised fluid from a fluid inlet 100 up to the chambers defined by the cylinders 9, 10 and 11, 12. Preferably, the inlet 100 is arranged on the assembly side elongated portion 2, advantageously near to the disc outlet side attachment portion 8,

In accordance with a general embodiment, the ducts inside the monobiock caliper body I are made through perforation or boring, preferably through the fluid inlet 100, as well as an outlet 101 for connecting to a drainage device and, advantageously from the openings defined by the cylinders 9, 10 and 11, 12 suitable for housing and extracting the pistons, as well as preferably, to place in communication the ducts made inside the elongated attachment side portion 2 with the ducts made inside the elongated non-attachment side portion 3 through holes made in a bridσe, for example in the central bridge 6.

In accordance with an embodiment., these ducts for supplying pressurised fluid have a divided configuration consisting of portions of rectilinear sections obtained as a consequence of the perforations .

In accordance with an embodiment, for example, as depicted in figure 15 and in the section 16, the defined chambers of the cylinders 10 and 12 are placed in communication with one another through holes made in the central bridge 6 obtained with perforations 36, 37 that join together the portions near to the bottom 25, 27 of the cylinder. The ends of the perforations foreseen in the outer surface of the bridge, on the side from which the perforating tip entered, are widened and threaded so as to be able to be closed with plugs. Preferably, the ducts are made with perforations by introducing a tool as indicated by the arrows 102 and 103 of figure 16.

As can be seen from figures 17 and 18, the pressurised fluid that through the ducts 36 and 37 goes from the chamber defined by the cylinder 12 to the chamber defined by the cylinder 10, passes to the cylinder 11 through a duct made with converging perforations 106, 10/ made through the mouths of the chambers defining the cylinders 11 and 12, as indicated by the arrows 104 and 105 of figure 18.

As can be seen from figure 19 and from the section 20, the chamber defined by the cylinder 12 is placed in communication with the opening for coupling with a drainage device 101 through a perforation 108 again made by the mouth of the chamber defined by the cylinder 12 converging with the perforation made to obtain the opening for coupling with the drainage device 101.

As can be seen from the section of figure 20, the ducts obtained with the perforations 108 and 110 are made by inserting the tool as indicated by the arrows 109 and 110 of figure 20,

As can be seen from figure 21 and from the section 22, the chambers defined by the cylinders 11 and 12 are also placed in communication through the ducts made with perforations 114 and 115 obtained by inserting the tools as indicated by the arrows 111 ^■ and 113 through the mouths of the chambers defined by the cylinders 11 and 12. The inlet for • the fluid 100 ^" is placed in communication with the chamber defined by the cylinder 11 through a perforation 116 obtained again by introducing the tool through the mouth of the chamber defined by the cylinder 11.

Thanks to the provision of a caliper body as defined above it is possible to obtain a structure that is particularly resistant to the high stresses generated by sudden braking, for example like in racing vehicles, in particular like in motorcycles from the Moto-GP category.

At the same time, thanks to the characteristics of the caliper body described above, the caliper stressed with maximum braking will have an extremely low deformation Lh Jt will avoid undesired travels of the brake lever giving the user a sensation of extreme responsiveness of the braking system.

.At the same time, thanks to the caliper body as described above, the overall weight will be lower.

For example, from a test carried out using a caliper made according to the state of the art compared with the solution described here, it emerged that by measuring the rigidity of the caliper body- evaluated based on the amount of fluid that the caliper absorbs at the maximum use pressure on the vehicle, the calit.or shows an increased rigidity of 1-5% compared to a reduction of the weight by about 10-15%.

Moreover, thanks to the caliper body, as described above it is possible to substantially reduce, for the same characteristics of rigidity or at the same weight, the overall bulk.

In accordance with a further embodiment, a caliper body 1 comprises elongated portions 2, 3 connected together by a third central bridge 6. Said central bridge, viewed in the tangential or circumferential direction, has a bulk with a rounded outer surface like a tortoise shell. In accordance with a further embodiment, said central bridge 6 with respect to a middle plane of the disc on which the body of the caliper is arranged to straddle it, or plane parallel to the braking surfaces of the disc passing through the middle of the body, is divided into two parts 100, 101. A first part 100 of the central bridge 6 is connected to the elongated attachment side portion, a second part 101 of the bridge is connected with the elongated non-attachment side portion. Said second part 101 of the central bridge 6 connects to the elongated non-attachment side portion and is in its radially outer surface undercut forming a recess 102 or a lowering that is suitable for making it easier to dismount the wheel of the vehicle, further reducing the radial bulk of the caliper body. A man skilled in the art can bring modifications, adaptations and replacements of elements with others that are functionally equivalent to the embodiments of the device described above, in ^■ order to satisfy contingent requirements, without departing from the scope of the following claims. Each of the characteristics described as belonging to a possible embodiment can be made independently from the other embodiments described.