(19)
(11)EP 3 321 536 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
10.08.2022 Bulletin 2022/32

(21)Application number: 16823923.4

(22)Date of filing:  07.07.2016
(51)International Patent Classification (IPC): 
F16D 55/226(2006.01)
B60T 17/22(2006.01)
F16D 65/18(2006.01)
B60T 8/52(2006.01)
(52)Cooperative Patent Classification (CPC):
B60T 8/52; B60T 17/221; F16D 65/183; F16D 2055/0008; F16D 55/226; F16D 2121/04
(86)International application number:
PCT/ES2016/070510
(87)International publication number:
WO 2017/009503 (19.01.2017 Gazette  2017/03)

(54)

MECHANISM FOR PROGRESSIVE BRAKING

MECHANISMUS FÜR PROGRESSIVES BREMSEN

MÉCANISME DE DOSAGE PROGRESSIF DU FREINAGE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 10.07.2015 ES 201531000

(43)Date of publication of application:
16.05.2018 Bulletin 2018/20

(73)Proprietor: Ortega Moreno, Lucio Antonio
28150 Valdetorres de Jarama (ES)

(72)Inventor:
  • Ortega Moreno, Lucio Antonio
    28150 Valdetorres de Jarama (ES)

(74)Representative: Álvarez López, Sonia 
Alvamark C/ Núñez de Balboa nº 31 3º 5
28001 Madrid
28001 Madrid (ES)


(56)References cited: : 
EP-A1- 1 855 023
WO-A1-02/063177
DE-A1-102007 016 250
GB-A- 732 950
US-A- 3 277 982
US-A- 3 923 345
WO-A1-90/06868
WO-A1-2010/109504
GB-A- 732 950
US-A- 2 419 113
US-A- 3 277 982
US-A- 5 036 960
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    OBJECT OF THE INVENTION



    [0001] The present invention relates to a mechanism for progressive braking, which is applicable to vehicle brakes.

    BACKGROUND OF THE INVENTION



    [0002] Currently, there exist anti-lock braking devices for vehicles, popularly known as ABS, which act on brakes of the type that comprise friction elements secured to the vehicle, usually brake pads mounted on the corresponding vehicle sleeve or bushing by means of calipers; these friction elements actuate frictional tracks secured to the wheels - usually brake discs -, and are actuated by means of a primary hydraulic circuit that is controlled by the brake pedal whilst driving, very often with the aid of an intensifier or assistant that amplifies the pressure implemented on the pedal such that the braking pressure exerted by the friction elements is capable of performing effective braking without requiring excessive force on the pedal.

    [0003] The action of this type of assisted braking is sometimes so potent that it may cause one or more wheels to lock up, especially on low-grip surfaces or in limit brakings. This situation reduces safety, since, except in the case of dry, optimal-grip surfaces and other situations, such as newly-fallen snow that may accumulate in front of the wheels when braking, the sliding increases the car stopping distance, thereby increasing the risk of collision, and, no less significantly, decreases vehicle stability, due to the loss of directional capabilities caused by the front wheels (which are those primarily responsible for braking) losing grip or to the displacement of the rear part of the vehicle caused by the rear wheels losing grip, or to both effects simultaneously.

    [0004] Precisely in order to solve this problem, anti-lock braking systems were designed that currently operate exclusively with electronic regulation, wherein sensors placed on the wheels (currently one on each wheel, although the early versions of these systems implemented sensors only for the rear axle) take continuous measurements (several times per second) of the wheel rotation speed, and send them to a control unit, which, if it detects a deceleration greater than certain pre-determined limits for effective braking, actuates solenoid valves inserted in the corresponding primary hydraulic circuit of each wheel, such that they open and release the braking pressure, thereby causing the wheel to recover its grip. As in the case of the sensor readings, the action of these valves is performed several times per second, which is noticed in the brake pedal as a clicking sound.

    [0005] These electronically-regulated systems have various disadvantages, which include:
    The sensors used are capacitive sensors, which are designed to prevent wearing elements, but nonetheless undergo changes in operation and failures due to temperature changes and hysteresis that may affect the correct operation of the system.

    [0006] The electronic elements used are susceptible to electrical failures, even more so in environments with high static electricity, such as a moving vehicle supported on the ground by means of electrically-insulated tyres.

    [0007] It is a very intrusive system, which is clearly perceptible to the drivers without them being capable of acting on it.

    [0008] Since it is an electronic aid, its use in competitions, such as car races (Formula 1®), is not permitted. <insert page 2a>

    DESCRIPTION OF THE INVENTION



    [0009] The configuration of the mechanism of the invention makes it possible to implement progressive braking, overall dispensing with electronic controls that are susceptible to failure and sensors that are sensitive to temperature changes and hysteresis, and which may be used in competitions, since it is not an electronic aid. Moreover, as unexpected advantages, smoother braking and better ventilation and cooling of the brakes have been detected.

    [0010] The mechanism for progressive braking of the invention is applied to brakes of the type that comprise friction elements secured to the vehicle, which actuate frictional tracks secured to the wheels, said friction elements being actuated by means of a primary hydraulic circuit. In the present document, Document US3277982 discloses vehicle braking mechanisms and more particularly a disc braking system that has a self-energizing feature. The braking system has a caliper type design where the components and apparatus for bringing about the self-energization are integral to a single support member.
    "frictional tracks secured to the wheels" is understood to mean that they rotate jointly with them, such as, for example, with brake discs mounted on a bushing, whereon, in turn, the corresponding wheels are mounted.

    [0011] Using this basic configuration, according to the invention, it is envisaged that the friction elements will comprise primary sectors actuated by means of the primary hydraulic circuit and secondary sectors actuated by, at least, one secondary hydraulic circuit.

    [0012] Said friction elements are mounted on the vehicle through attachment means that may be partially moved in the direction of rotation of the frictional tracks, the attachment means being associated with, at least, one hydraulic actuator that regulates the pressure in the secondary hydraulic circuit according to the movement of these friction elements, such that, when the brake pedal is pushed down, the friction elements come closer to the frictional tracks, and the push causes dragging of the friction elements in the direction of rotation or movement of the frictional tracks and, therefore, of their attachment means as well.

    [0013] The attachment means may be partially moved, i.e. their partial movement is limited, since, otherwise, effective braking would not take place, and they follow the direction and the rotation of the frictional tracks such that they do not stop actuating them during this movement. The variable movement of the attachment means - according to the braking friction applied - influences the hydraulic actuator, which is calibrated such that, in the event of excessive movement, compatible with conditions of lock-up or close thereto, it may regulate the pressure in the secondary hydraulic circuit, thereby reducing the braking pressure applied on the braking tracks by the secondary sectors of the friction elements; such regulation is automatic, since the movement of the attachment means and the regulation of the secondary hydraulic circuit by the hydraulic actuator are proportional to the braking intensity, which provides effective regulation of the braking. Moreover, the partial separation of the secondary sectors and the decrease in friction contribute to better ventilation of the brakes.

    [0014] In the present document, when reference is made to the fact that the friction elements are mounted on the vehicle through attachment means that may be partially moved in the direction of the frictional tracks, it is understood that this may refer to all the friction elements or only to some of them, whilst the rest may be mounted without the involvement of the partially moveable means. I.e., for example, in disc brakes wherein the friction elements are brake pads mounted on a caliper, and the braking track is formed by the sides of a brake disc, at least two calipers with the corresponding pads may be implemented, wherein only one of the calipers, associated with the hydraulic actuator, is mounted through partially moveable attachment means.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0015] 

    Figure 1 shows a view of a vehicle that incorporates the mechanism of the invention.

    Figure 2 shows a detail of the general elements of a wheel brake according to the mechanism of the invention.

    Figure 3 shows a detailed view of the friction elements, with the primary and secondary sectors thereof, for an embodiment wherein the secondary sectors are mounted on secondary supports and the primary sectors are mounted on primary supports, the secondary supports being mounted on the primary supports by means of pistons actuated by the hydraulic actuator and of regenerative springs.

    Figure 4 shows a view similar to that shown in Figure 3, for another embodiment, wherein the secondary supports are mounted on the primary supports by means of double-effect pistons.

    Figure 5 shows a detail of the partially moveable attachment elements, in a front view of a brake disc mounted on a bushing.

    Figure 6 shows a partial detail of a friction element of the mechanism of the invention in the form of a brake pad, wherein the primary and secondary sectors may be observed.


    DESCRIPTION OF AN EMBODIMENT OF THE INVENTION



    [0016] The mechanism (1) for progressive braking of the invention is applied to brakes of the type that comprise friction elements (2) secured to the vehicle (3) which actuate frictional tracks (4) secured to the wheels, the friction elements (2) - for example, brake calipers with the corresponding pads, as shown in the figures, and wherein the frictional tracks (4) are the sides of brake discs - being actuated by means of a primary hydraulic circuit (5) with the corresponding cylinders (50) (see Figs. 3 and 4).

    [0017] According to the invention, the friction elements (2) comprise primary sectors (2a) actuated by the primary hydraulic circuit (5) and secondary sectors (2b) actuated by, at least, one secondary hydraulic circuit (6); and said friction elements (2) are mounted on the vehicle through attachment means (7) that may be partially moved in the direction of rotation of the frictional tracks (4) (see these means in Figure 5).

    [0018] The partially moveable attachment means (7) are associated with, at least, one hydraulic actuator (8) (see Fig. 2), which regulates the pressure in the secondary hydraulic circuit (6), in order to regulate the braking pressure of the secondary sectors (2b) according to the movement of the friction elements (2). Said partially moveable attachment means (7) comprise, for example, rails (7a) through which slide carriages (7b) equipped with derailment retainers (7c) travel, as may be seen in Figure 5.

    [0019] Moreover, it is envisaged that the partially moveable attachment means (7) will be associated with, at least, one motion damper (9) (go back to Fig. 2), which, in these examples of the invention, comprises, at least, one piston (10) connected to a third hydraulic circuit (11) equipped with pressure regulator elements (12), such that, by actuating these pressure regulator elements (12), the movement of the attachment means (7) may be regulated according to the braking force or friction, in order to, for example, adjust to dry or wet conditions. Moreover, it is envisaged that said pressure regulator elements (12) of the third hydraulic circuits (11), corresponding to each of the wheels (60), will be connected through a brakeforce distributor (14), as shown in Figures 1 and 2, such that the action of the mechanism (1) on the different wheels (60) may be co-ordinated. Moreover, the brakeforce distributor (14) may be associated with a hydraulically-operated self-locking differential, not represented, such that the mechanism may interact with the traction on the drive wheels.

    [0020] Moreover, in the invention it is envisaged that the partially moveable attachment means (7) will be associated with, at least, one recovery element (15), such that, when action on the brake pedal (61) ceases, the resting position is recovered. Said recovery element (15) and the motion damper (9) are preferably mounted coaxially, as shown in Figure 2.

    [0021] On the other hand, the primary sectors (2a) are mounted on primary supports (20a) (see Figs. 3 and 4), whereas the secondary sectors (2b) are mounted on secondary supports (20b), the secondary supports - for each wheel - (20b) being moveably mounted on the primary supports (20a). For example, Figure 3 shows an embodiment wherein the secondary supports (20b) are mounted on the primary supports (20a) by means of pistons (17) actuated by the corresponding hydraulic actuator - that of the same wheel - (8) by means of the corresponding secondary hydraulic circuit (6), and of regenerative springs (18). Moreover, in this case, the hydraulic actuator (8) in each wheel operates under compression, i.e. ahead with respect to the direction of rotation of the wheel, although it may also operate under extension (behind with respect to the direction of rotation of the wheel) by attaching it to the friction elements (2), a variant that is not represented in the figures. Moreover, in said Figure 3, the pistons (17) cause the opening of the secondary sectors (2b) - thereby reducing the braking pressure - and the regenerative springs (18) cause the closing thereof. In this manner, if the braking is too intense, the braking pressure decreases when the secondary sectors (2b) are opened, and the affected wheel (60) recovers its grip. The operation may also have the reverse configuration, which is not represented.

    [0022] In Figure 4, another configuration is envisaged, wherein the secondary supports (20b) are mounted on the primary supports (20a) by means of double-effect pistons (17a), and which comprises two hydraulic actuators (8) in each wheel, one of them operating on one of the directions of the double-effect pistons (17a), and the other operating on the opposite direction, such that excessive intensification of the braking causes the secondary sectors (2b) to open, and vice-versa. The second hydraulic actuator (8) is outlined with a dashed line in Figure 2.

    [0023] In any case, as an additional feature of the invention, it is envisaged that, in the resting position, the secondary sectors (2b) will be slightly ahead with respect to the primary sectors (2a), as shown in Figures 3 and 4, thereby leading to a more progressive braking in the beginning. In any case, the movement of the partially moveable attachment means (7) at the beginning of the braking contributes to its progressiveness.

    [0024] Finally, the invention envisages the additional use of temperature sensors (19), applied in Figure 2 to the calipers of the friction elements, although they may also be applied to the sectors (2a, 2b) and/or the primary or secondary hydraulic circuits, which are associated with valves (21) inserted in the third hydraulic circuit (11) of each wheel (60), in order to regulate the braking pressure on the corresponding wheel according to the temperature. Said association, which is not represented, may be performed, for example, by means of control electronics.

    [0025] Having sufficiently described the nature of the invention, as well as the way to implement it, we state that some details of the aforementioned arrangements not represented in the attached drawings may be modified, provided that they do not alter the fundamental principle.


    Claims

    1. Mechanism (1) for progressive braking applicable to brakes comprising friction elements (2) secured to the vehicle (3), which act on frictional tracks (4) secured to the wheels, the friction elements (2) being actuated by means of a primary hydraulic circuit (5); wherein the friction elements (2) comprise primary sectors (2a) actuated by the primary hydraulic circuit (5) and secondary sectors (2b) actuated by, at least, one secondary hydraulic circuit (6); said friction elements (2) are mounted on the vehicle through attachment means (7) partially moveable in the direction of rotation of the frictional tracks (4); and the partially moveable attachment means (7) are associated with, at least, one hydraulic actuator (8) which regulates the pressure in the secondary hydraulic circuit (6), in order to regulate the braking pressure of the secondary sectors (2b) according to the movement of the friction elements (2), characterized in that the partially moveable attachment means (7) comprise rails (7a) through which slide carriages (7b) equipped with derailment retainers (7c) travel.
     
    2. Mechanism (1) for progressive braking according to claim 1, wherein the partially moveable attachment means (7) are further associated with, at least, one motion damper (9).
     
    3. Mechanism (1) for progressive braking according to claim 2, wherein the motion damper (9) comprises, at least, one piston (10) connected to a third hydraulic circuit (11) equipped with pressure regulator elements (12).
     
    4. Mechanism (1) for progressive braking according to claim 3, wherein the pressure regulator elements (12) of the third hydraulic circuits (11) corresponding to each of the wheels are connected by means of a brakeforce distributor (14).
     
    5. Mechanism (1) for progressive braking according to claim 4, wherein the brakeforce distributor (14) is associated with a hydraulically-operated self-locking differential for the vehicle (3).
     
    6. Mechanism (1) for progressive braking according to claim 1, wherein the partially moveable attachment means (7) are further associated with, at least, one recovery element (15).
     
    7. Mechanism (1) for progressive braking according to claim 6, wherein the recovery element (15) and the motion damper (9) are mounted coaxially.
     
    8. Mechanism (1) for progressive braking according to claim 1, wherein the primary sectors (2a) are mounted on primary supports (20a), whereas the secondary sectors (2b) are mounted on secondary supports (20b); the secondary supports in each wheel (20b) being moveably mounted on the primary supports (20a).
     
    9. Mechanism (1) for progressive braking according to claim 8, wherein the secondary supports (20b) are mounted on the primary supports (20a) by means of pistons (17) actuated by the corresponding hydraulic actuator (8) and of regenerative springs (18).
     
    10. Mechanism (1) for progressive braking according to claim 8, wherein the secondary supports (20b) are mounted on the primary supports (20a) by means of double-effect pistons (17a); each wheel comprising two hydraulic actuators (8), one of them operating on one of the directions of the double-effect pistons (17a) and the other operating on the opposite direction.
     
    11. Mechanism (1) for progressive braking according to claim 1, wherein, in the resting position, the secondary sectors (2b) are slightly ahead with respect to the primary sectors (2a).
     
    12. Mechanism (1) for progressive braking according to any of claims 3 to 5 , further comprising temperature sensors (19) associated with valves (21) inserted in the third hydraulic circuit (11) of each wheel, in order to regulate the braking pressure in the corresponding wheel according to the temperature.
     


    Ansprüche

    1. Mechanismus (1) zum progressiven Bremsen, der auf Bremsen anwendbar ist, mit am Fahrzeug (3) befestigten Reibungselementen (2), die auf an den Rädern befestigte Reibungsbahnen (4) wirken, wobei die Reibungselemente (2) mittels eines primären Hydraulikkreises (5) betätigt werden; wobei die Reibungselemente (2) primäre Sektoren (2a), die durch den primären Hydraulikkreis (5) betätigt werden und sekundäre Sektoren (2b), die durch mindestens einen sekundären Hydraulikkreis (6) betätigt werden, umfassen; wobei die Reibungselemente (2) an dem Fahrzeug durch Befestigungsmittel (7) angebracht sind, die teilweise in der Drehrichtung der Reibungsbahnen (4) bewegbar sind; und wobei die teilweise bewegbaren Befestigungsmittel (7) mindestens einem hydraulischen Stellglied (8) zugeordnet sind, das den Druck in dem sekundären Hydraulikkreis (6) reguliert, um den Bremsdruck der sekundären Sektoren (2b) gemäß der Bewegung der Reibungselemente (2) zu regulieren, dadurch gekennzeichnet, dass die teilweise bewegbaren Befestigungsmittel (7) Schienen (7a) umfassen, durch die sich Schlitten (7b) bewegen, die mit Entgleisungshalterungen (7c) ausgestattet sind.
     
    2. Mechanismus (1) zum progressiven Bremsen nach Anspruch 1, wobei die teilweise beweglichen Befestigungsmittel (7) ferner mindestens einem Bewegungsdämpfer (9) zugeordnet sind.
     
    3. Mechanismus (1) zum progressiven Bremsen nach Anspruch 2, wobei der Bewegungsdämpfer (9) mindestens einen Kolben (10) umfasst, der mit einem dritten Hydraulikkreis (11) verbunden ist, der mit Druckreglerelementen (12) ausgestattet ist.
     
    4. Mechanismus (1) zum progressiven Bremsen nach Anspruch 3, wobei die Druckreglerelemente (12) der dritten Hydraulikkreise (11), die zu jedem der Räder gehören, mittels eines Bremskraftverteilers (14) verbunden sind.
     
    5. Mechanismus (1) zum progressiven Bremsen nach Anspruch 4, wobei dem Bremskraftverteiler (14) ein hydraulisch betätigtes selbsthemmendes Differential für das Fahrzeug (3) zugeordnet ist.
     
    6. Mechanismus (1) zum progressiven Bremsen nach Anspruch 1, wobei die teilweise beweglichen Befestigungsmittel (7) ferner mindestens einem Rückgewinnungselement (15) zugeordnet sind.
     
    7. Mechanismus (1) zum progressiven Bremsen nach Anspruch 6, wobei das Rückstellelement (15) und der Bewegungsdämpfer (9) koaxial montiert sind.
     
    8. Mechanismus (1) zum progressiven Bremsen nach Anspruch 1, wobei die Primärsektoren (2a) auf Primärstützen (20a) montiert sind, während die Sekundärsektoren (2b) auf Sekundärstützen (20b) montiert sind; wobei die Sekundärstützen in jedem Rad (20b) beweglich auf den Primärstützen (20a) montiert sind.
     
    9. Mechanismus (1) zum progressiven Bremsen nach Anspruch 8, wobei die sekundären Träger (20b) auf den primären Trägern (20a) mittels Kolben (17), die durch das entsprechende hydraulische Betätigungselement (8) und von Rückstellfedern (18) betätigt werden, montiert sind.
     
    10. Mechanismus (1) zum progressiven Bremsen nach Anspruch 8, wobei die sekundären Träger (20b) auf den primären Trägern (20a) mittels doppelt wirkender Kolben (17a) montiert sind; wobei jedes Rad zwei hydraulische Stellglieder (8) umfasst, von denen eines auf eine der Richtungen der doppelt wirkenden Kolben (17a) und das andere auf die entgegengesetzte Richtung wirkt.
     
    11. Mechanismus (1) zum progressiven Bremsen nach Anspruch 1, wobei in der Ruheposition die sekundären Sektoren (2b) in Bezug auf die primären Sektoren (2a) geringfügig voraus sind.
     
    12. Mechanismus (1) zum progressiven Bremsen nach einem der Ansprüche 3 bis 5, der des Weiteren Temperatursensoren (19) umfasst, die mit Ventilen (21) verbunden sind, die in den dritten Hydraulikkreis (11) jedes Rades eingesetzt sind, um den Bremsdruck in dem entsprechenden Rad in Abhängigkeit von der Temperatur zu regulieren.
     


    Revendications

    1. Mécanisme (1) de freinage progressif applicable aux freins comprenant des éléments de friction (2) fixés au véhicule (3), qui agissent sur des bandes de friction (4) fixées aux roues, les éléments de friction (2) étant actionnés au moyen d'un circuit hydraulique primaire (5) ; dans lequel les éléments de friction (2) comprennent des secteurs primaires (2a) actionnés par le circuit hydraulique primaire (5) et des secteurs secondaires (2b) actionnés par, au moins, un circuit hydraulique secondaire (6) ; lesdits éléments de friction (2) sont montés sur le véhicule par l'intermédiaire de moyens de fixation (7) partiellement mobiles dans le sens de rotation des bandes de friction (4) ; et les moyens de fixation partiellement mobiles (7) sont associés à, au moins, un actionneur hydraulique (8) qui régule la pression dans le circuit hydraulique secondaire (6), afin de réguler la pression de freinage des secteurs secondaires (2b) en fonction du mouvement des éléments de friction (2), caractérisé en ce que les moyens de fixation partiellement mobiles (7) comprennent des rails (7a) à travers lesquels se déplacent des chariots coulissants (7b) équipés de dispositifs de retenue de déraillement (7c).
     
    2. Mécanisme (1) de freinage progressif selon la revendication 1, dans lequel les moyens de fixation partiellement mobiles (7) sont en outre associés à, au moins, un amortisseur de mouvement (9).
     
    3. Mécanisme (1) de freinage progressif selon la revendication 2, dans lequel l'amortisseur de mouvement (9) comprend au moins un piston (10) relié à un troisième circuit hydraulique (11) équipé d'éléments de régulation de pression (12).
     
    4. Mécanisme (1) de freinage progressif selon la revendication 3, dans lequel les éléments de régulation de pression (12) des troisièmes circuits hydrauliques (11) correspondant à chacune des roues sont reliés au moyen d'un répartiteur de force de freinage (14).
     
    5. Mécanisme (1) de freinage progressif selon la revendication 4, dans lequel le répartiteur de force de freinage (14) est associé à un différentiel autobloquant actionné hydrauliquement pour le véhicule (3).
     
    6. Mécanisme (1) de freinage progressif selon la revendication 1, dans lequel les moyens de fixation partiellement mobiles (7) sont en outre associés à, au moins, un élément de récupération (15).
     
    7. Mécanisme (1) de freinage progressif selon la revendication 6, dans lequel l'élément de récupération (15) et l'amortisseur de mouvement (9) sont montés coaxialement.
     
    8. Mécanisme (1) de freinage progressif selon la revendication 1, dans lequel les secteurs primaires (2a) sont montés sur des supports primaires (20a), tandis que les secteurs secondaires (2b) sont montés sur des supports secondaires (20b) ; les supports secondaires dans chaque roue (20b) étant montés de façon mobile sur les supports primaires (20a).
     
    9. Mécanisme (1) de freinage progressif selon la revendication 8, dans lequel les supports secondaires (20b) sont montés sur les supports primaires (20a) au moyen de pistons (17) actionnés par l'actionneur hydraulique correspondant (8) et de ressorts de régénération (18).
     
    10. Mécanisme (1) de freinage progressif selon la revendication 8, dans lequel les supports secondaires (20b) sont montés sur les supports primaires (20a) au moyen de pistons à double effet (17a) ; chaque roue comprenant deux actionneurs hydrauliques (8), l'un d'eux fonctionnant dans l'une des directions des pistons à double effet (17a) et l'autre fonctionnant dans la direction opposée.
     
    11. Mécanisme (1) de freinage progressif selon la revendication 1, dans lequel, dans la position de repos, les secteurs secondaires (2b) sont légèrement en avant par rapport aux secteurs primaires (2a).
     
    12. Mécanisme (1) de freinage progressif selon une des revendications 3 à 5 , comprenant en outre des capteurs de température (19) associés à des soupapes (21) insérées dans le troisième circuit hydraulique (11) de chaque roue, afin de réguler la pression de freinage dans la roue correspondante en fonction de la température.
     




    Drawing














    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description