KR20190008144A - Decoupled electronic brake system - Google Patents

Abstract

Disclosed is a system in which a transmission device (1) includes a return and shock absorbing device (100) between a control rod (140) and a pusher (150). The system includes: a spherical bowl (141) provided at the end of a control rod (140) and having a planar rear surface (141b) perpendicular to an axis (X1X1) of the control rod (140); a sleeve (160) surrounding the rod (140) sliding inside a bore (152) and supported by the rear surface (141b); a centering spring (110) supported on a floating ring (120) in a pusher (150) and on a centering sleeve (160); and a return spring (120) received within the bore (152) and supported on the floating ring (120) and on an annular stop portion (122) securely connected to the pusher (150).

Description

[0001] DECOUPLED ELECTRONIC BRAKE SYSTEM [0002]

The present invention relates to a decoupled electronic braking system having a mobile transmission device linking a brake pedal to an electrohydraulic brake actuator, the control rod being linked to a brake pedal and a piston- wherein the pusher is linked to the end of the control rod by a ball joint and is returned to the thrust of the control rod by a return spring, Shaped support surface for freely rotatably / pivotally receiving the cup-shaped support surface.

Separate electromagnetic brake systems, primarily used in hybrid and electric vehicles, allow dynamic braking (regenerative braking) and exhibit a certain degree of resilience in adjusting the sensation of the pedal according to the user's needs.

In such a system, unlike a conventional system in which the control rod is linked to a pneumatic or electric brake booster that subsequently transfers the amplified input force applied by the driver to the hydraulic components of the control unit, the control of the brake pedal of the vehicle The operating end of the rod is characteristically linked to a hydraulic piston or pusher that slides inside the bore of the brake control module. This allows the pusher and guiding features that slide inside the bore to be directly influenced by all the forces coming from the pedal when the driver steps on the pedal or releases the pedal in various braking situations, Become more susceptible to accidents and to be identified as premature seal defects in the hydraulic system.

Moreover, the manufacturer requires that the control rod (which must provide a certain degree of angular freedom to adapt to the dynamics of the brake pedal) when installed in the vehicle is axially aligned with respect to the control module. This is to facilitate mounting and to prevent damage, especially when the rod is guided through an orifice in the panel separating the engine compartment from the passenger compartment. In the case of a pneumatic or electric brake booster, this alignment function is naturally provided by one of the springs of the servo control valve mechanism. In the case of hydraulically operated units, the available space does not allow such springs to be considered.

Moreover, the absence of a brake booster between the brake pedal and the hydraulic component of the actuator unit may cause an adverse effect due to the dynamic behavior of the brake pedal, especially when the pedal suddenly releases from its deeply depressed position. Natural damping of the braking system or conventional brake booster control strategy then limits the rate at which the pedal returns to its rest position to an acceptable level, while in a separate system, the pedal is released by the spring of the system Return to rest at high speed under the influence of force and hydraulic pressure. When the internal components of the control module return to their rest position at high speed, the kinetic energy of all the moving elements, including the pedal, is dissipated upon impact. This results in the transfer of high energy levels and significant forces within the system. The resulting adverse effects are summarized as follows:

- confusing sound effects / vibrations for the driver;

One or more bounce cycles, i.e. a reversal movement of the pedal between its rest position and its depressed position, causing a brake command not intended by the driver and to be detected by the sensor;

- deterioration, destruction or detachment of the mechanical components of the pedal box and link components in the control unit.

Finally, the conventional brake booster system has a valve spring that allows the control rod to be aligned with respect to the geometric axis of the module for mounting the module in a vehicle that is not present in a separate cable operated brake system, It is linked to the component.

1 shows a prior art discrete braking system including a transmission device 1 'linking a brake pedal (not shown) to a brake control module 2'. The brake pedal is located on the passenger compartment H side of the partition 3 'separating the passenger compartment H and the engine compartment EM is connected to the control module 2' and other components of the braking system ).

A control module 2 ', which is an electromechanical or electrohydraulic device (not shown in detail), receives a brake control signal from the brake pedal. The movement of the brake pedal is transmitted by a control rod 4 'linking the brake pedal to the pusher 5'. The piston-shaped pusher 5 'is guided inside the cylinder 24' of the axis XX of the control module 2 '. The movement of the pusher 5 'is detected by a sensor 6', which transmits a signal which generates a control signal applied to the braking circuit.

The pusher 5 ', which is urged by the control rod 4', is returned to the neutral position, in particular by the return spring 7 '. The end portion 4a'of the control rod 4'is designed to pivotally move the ball joint 8 'since the pivotal movement of the brake pedal imparts a pivotal movement on the control rod 4' relative to the axis XX of the pusher 5 ' 'To the pusher 5'.

The ball joint 8 'is formed by a ball 81' supported by the end 4b 'of the control rod 4' and fitted in the spherical cup 82 'of the pusher 5'. The ball 81 'is retained in the cup 82' by an elastic washer 83 'that is embedded in the inner groove of the pusher 5' and freely retains the control rod 4 '. At the position of the transmission device 1 'before being mounted on the vehicle, the control rod 4' is inclined with respect to the axis XX by an angle? Due to its own weight.

The chamber formed by the cylinder 24 'of the module 2' on the upstream side of the pusher 5'is not only one or more hydraulic connections 13 'to other components of the braking system but also a brake fluid reservoir And may have a connection portion for communication. These various means are merely referred to and not described in detail, since they are not directly required for an understanding of the present invention.

Fig. 1 shows a mounted power transmission device 1 'attached to the partition 3'. The U-shaped clevis at the end 4b 'of the control rod 4' is linked to the brake pedal (not shown). In this position, the control rod 4 'of the axis X1 X1 is inclined by an angle? (Here, on the axis XX), which corresponds to the brake pedal operating position as well as the rest position, Changes during operation movement.

In these various positions, the control rod 4 'does not act on the axis XX of the pusher 5', producing a pivot torque applied to the pusher 5 ', broadly speaking, ) At the end of the pusher 5 'at the inlet 11' of the bore of the cylinder 24 'and / or at the spring 7' side with respect to the guide zones 11 ', 12' And is supported against the guide section 12 '. The active guide sections 11 ', 12' above and / or below the pushers 5 'according to the orientation of FIG. 1 are applied by the control rod 4' in accordance with the inclination? Of the control rod 4 ' Lt; RTI ID = 0.0 > thrust. ≪ / RTI >

It is an object of the present invention to include a mobile transmission device for linking a brake pedal to a brake module to facilitate its positioning and mounting within the vehicle and to reduce the duration of its operation and then to reduce the wear in the event of an accidental release of the brake pedal And to compensate for the radial influence applied by the control rod to absorb the impact.

To this end, the subject of the invention is a discrete braking system of the type described above, wherein the transmission device comprises a return and buffering device between the control rod and the pusher, the device being supported by a pusher,

A. spherical bowl at the end of the control rod and having a spherical front support surface and a planar rear surface perpendicular to the axis of the rod;

B. a sleeve which freely surrounds the control rod which slides inside the bore of the pusher and is supported against the rear face of the spherical bowl perpendicular to the axis of the pusher;

C. a centering spring supported within the pusher against the floating ring and against the centering sleeve to bias the centering sleeve and tilt the spherical bowl and control rod toward the axis of the pusher relative to the weight of the control rod;

D. a return spring received within the bore of the pusher and supported against an annular stop which is rigidly connected to the pusher as well as to the floating ring;

E. In the mounting position of the electric device, the floating ring is separated from the sleeve by the gap.

The braking system according to the present invention, among other things, facilitates the installation of the separable braking system in the vehicle by aligning the axle of the transmission device with the control rod, and then, by means of the control rod to the shaft of the transmission device, To compensate for the radial influence exerted on the control rod by the brake pedal. The centering spring, in combination with the return spring of the return and shock absorber, suitably generates a component of the force which is transmitted to the control rod by the brake pedal when the brake is actuated and which opposes the component of the force applied on the pusher . This reduction of these radial components reduces the wear between the pusher and the cylinder of the control module and thus prevents the consequences such as excessively high wear and premature leakage.

According to one advantageous feature, the centering spring and the return spring, which are mounted in series between the sleeve and the annular stop, are dimensioned such that, at equilibrium, in the mounting position, the floating ring is separated from the sleeve by the gap.

According to another advantageous feature, the pusher has a bore formed therein with a front part forming a shoulder therebetween and a rear part with a larger diameter, the floating ring being movable within this rear part and being supported on the shoulder by the thrust of the return spring And the length of the front portion that slidably receives the sleeve is greater than the length of the sleeve to leave a free clearance between the sleeve and the floating ring and thus to support against the shoulder. In this case there is not only a certain level of compensation for the component of the force applied by the brake pedal on the pusher provided but not aligned with its movement axis and thus also the returning shock caused by the accidental release of the brake pedal It is possible to select a return spring with better properties to more effectively compensate and this impact is caused by the return spring acting on the pusher and the sudden return of the pusher under the influence of the hydraulic pressure of the control module.

According to another advantageous feature, the sleeve includes an inner collar to which both the planar rear surface of the bowl and the centering spring are supported.

According to the invention, the centering spring and the return spring are helical springs surrounding the control rod. The centering spring and return spring may also be a stack of Belleville washers.

According to another feature, the annular stop is a split ring engaged in the groove of the bore of the pusher. This mounting system is particularly simple and quick in positioning the return and dampening device according to the invention.

According to another feature, a buffer element is interposed between the pusher and the bore to absorb a portion of the kinetic energy of the pusher sliding inside the bore.

According to another advantageous feature, the buffer element is a friction element incorporated in the pusher and / or in the bore.

Thus, in summary, the braking system according to the present invention is particularly advantageous at the start of the installation of the system in the vehicle and both during operation and use, by its simplicity and by the effects provided by this braking system , Providing very high reliability for this braking system.

The present invention will be described in more detail below with the aid of an exemplary embodiment of a discrete electronic braking system including a transmission device that links a brake pedal to a brake control module as shown in the accompanying drawings.
1 is a partial schematic cross-sectional view of a known transmission device installed between a brake pedal and a control module;
2 is a schematic sectional view of a transmission device of a brake system according to the first embodiment of the present invention.
3 is a cross-sectional view of a power transmission device according to the present invention in an installed position linked to a brake pedal;
Fig. 4 shows the device of Fig. 3 operated by a brake pedal; Fig.
5 is a cross-sectional view of the transmission device after sudden release of the brake pedal.
6 is a cross-sectional view of a variant of the transmission device in the installed position;
7 is a cross-sectional view of another modification of the electric device in the installation position;

2, a separate brake system according to the present invention, shown before being installed in a vehicle, includes a transmission device 1 for linking a brake pedal to a control module 2. As shown in Fig. The transmission device 1 and the control module 2 are provided with a cylinder 22 for accommodating a pusher 150 constituting a piston which is dependent on the return spring 23 and an orifice 25 26 form a hydraulic chamber 24 linked to the brake fluid reservoir and the braking circuit. The bottom portion 27 of the housing is, for example, an additional element. The movement of the brake pedal actuated by the driver is transmitted by the control rod 140 linked to the pusher 150 guided inside the cylinder 22 of the axis XX of the module 2; The movement is detected by a sensor 27 which generates a control signal for the braking circuit. The transmission device 1 includes a return and buffer device 100 for linking the end portion 140a of the control rod 140 to the pusher 150 in addition to the pusher 150 and the control rod 140. [ The pusher 150 has a bottom 151 that separates the side facing the chamber 24 and the side facing the control rod 140 while the side facing the control rod has a bore 152.

The return and buffer device 100 consists of a spherical bowl 141 at the front end 140a of the control rod 140 opposite the end 140b linked to the brake pedal.

The spherical bowl 141 is formed of a spherical front surface 141a and a planar rear surface 141b. The spherical front surface 141a is fitted into a spherical cup 153 having the same radius formed on the bottom 151 of the pusher 150. [ The plane surface of the rear surface 141b of the bowl 141 is perpendicular to the axis X1X1 of the control rod 140. [ The diameter of the bowl 141 is smaller than the diameter of the bore 152.

A cylindrical sleeve 160 that freely surrounds the control rod 140 slides within the bore 152. The sleeve has a collar 161 therein. The diameter of the bowl 141 is smaller than the inner diameter of the sleeve 160 so that it is at least partially received within the sleeve 160 at the front of the inner collar 161. In other words, the planar surface 141b of the bowl 140 is supported against the collar 161 according to a tilt of the axis X1X1 of the rod 140 relative to the axis XX, at at least one point. This collar 161 of the cylindrical sleeve 160 constituting the centering sleeve is therefore in a plane perpendicular to the axis XX of the pusher 150.

A centering spring 110, for example a helical compression spring, presses the floating ring 120 sliding inside the bore 152 of the pusher 150. The floating ring 120 is pressed against the pusher 150 by the return spring 121 and the annular stop 122 in the form of a split ring engaged in the groove 154, for example. The centering spring 110 freely surrounds the control rod 140 in the same manner as the return spring 121.

The centering spring 110 is partially engaged in the sleeve 160 on the side of the control rod 140 and is supported against the inner collar 161 so that the sleeve 160 is moved relative to the surface 141b of the bowl 141 It pushes.

3), the gap 130 is maintained between the sleeve 160 and the pusher 150 and the gap 131 is between the sleeve 160 and the floating ring 122 Which equilibrium position results from the characteristics selected for the two springs 110,

Thus, in summary, the control rod 140 movement return and shock absorbing device 100 includes a spherical bowl 141 and associated elements, a sleeve 160 and associated elements, a centering spring 110, A spring 120, and an element associated with these two springs.

In the absence of the return and damping device 100, consisting of the spherical bowl 141, the sleeve 160 and the centering spring 110, particularly with the planar rear face 141b, the control rod 140, before being mounted to the vehicle, It will pivot under the influence of its own weight and its axis X1X1 will no longer align with XX.

The centering spring 110 and the return spring 121 are arranged to pass through the control rod 140 through the opening 31 in the partition wall 3 and then into the housing 2 of the module 2, Compensates for this pivotal movement of the control rod 140 such that these springs are within the axis XX of the pusher 150 to attach the spring 21 to the bulkhead 3.

Actually, before mounting in a vehicle, the electric device 1 according to the present invention is in the aligned position of Fig. This position precedes the position where the brake pedal is assembled together with the end portion 140b, which is the assembling position shown in Fig. The control rod 140 is then inclined with respect to the axis XX of the transmission device 1, without any action on the brake pedal, at the installation position at rest. The lower point of the edge of the planar surface 141b of the bowl 141 is pressed against the collar 161 of the centering sleeve 160 to form a clearance 130 between the rear portion of the sleeve 160 and the floating ring 120 The centering spring 110 and the return spring 121 are slightly compressed.

The end portion 140b of the control rod 140 and the brake pedal are assembled together in the second stage from the passenger compartment H. [

The dimensioning of the centering spring 110 is calculated based on the geometric indications of FIG. 2 and the physical characteristics of the control rod 140 and the pusher 150. The centering spring 110 aligns with the pusher 150 to position the module 2 and maintains it in order to keep it from affecting the movement of the control rod 140 once it is installed, Lt; RTI ID = 0.0 > calculated power. ≪ / RTI > The control rod 140 will not align with the axis XX as shown in FIG. 3, and therefore the centering spring 110 will not be aligned with the axis XX, And the return spring 120. However, the force applied at that moment by the spring 110 is negligible in this dynamic chain with respect to the thrust applied on the control rod 140 by the return springs 23, 121 and the brake pedal, Lt; RTI ID = 0.0 > device < / RTI >

The pusher 150 includes two guide sections 171 and 172 in the cylinder 22: one guide section 171 and a pusher 150 between the front end of the pusher 150 and the end of the cylinder 22, And another guide section 172 between the rear ends of the cylinders 22.

3 shows a system installed in a vehicle. At rest, the rod 140 linked to the brake pedal is raised relative to its aligned position to form an angle beta; The rod 140 may be potentially inclined below the axis XX.

The clearance 12 between the sleeve 160 and the floating ring 120 is such that in this angular range the load is applied to the sleeve 160 or to the ring (not shown) to prevent the spring 121 from potentially generating an excessive level of force. 120, but rather should be sufficient to allow angular pivoting of the control rod 140 located within an angular range of +/- 3 degrees with respect to the axis XX, Will have an adverse effect to reduce the distribution of radial forces / forces within the zone.

When the brake pedal is initially actuated, the input force F is split into a horizontal component Fh and a vertical component Fv at the interface between the bowl 141 of the rod 140 and the pusher 150. The vertical component Fv is thus distributed between the guide surfaces 171 and 172 according to the distances L1 and L2. This distribution of force is dependent on the position of the contact point between the end 140a of the rod 140 and the pusher 150 relative to the guide surface 172 and on the angular position of the control rod 140 relative to the axis XX , That is, above or below it. 3, this contact point is initially on the right side of the guide surface 172, which means that the reaction of the contact surface 171 of the bore is oriented in the downward direction Fr2- at the upper part of the bore 22. When the brake pedal is actuated, the contact point approaches the guide surface and potentially coincides with the guide surface to finally move to the left of this contact point. At this point, there will then be an upward force, Fr2 +, in the lower portion of the bore 22.

In all cases, at rest, the end 140a of the rod 140 is much closer to the guide surface 172 than to the other guide surface 171. This results in a distribution of forces between the guide surfaces that significantly rest on the side 172 during the initial portion of the travel range of the pusher 150. This initial portion is most often used in everyday braking situations, so that the concentration of wear over the service life of both pusher 150 and bore 22 is very high in this zone, making it vulnerable.

According to the present invention, however, the force F2 of the springs 110, 121 is applied on the outer edge of the rear shoulder of the spherical bowl 141 of the rod 140 via the sleeve 160, To generate a counterclockwise torque applied thereto. This torque causes the upward force to be applied on the guide surface 172 of the pusher 150 against the downward force induced in the same surface by the component Fv. Thus, the reaction force Fr1 + may be reduced, neutralized, or even minus Fr1-, depending on the relative values of the various variables of the system, including the travel of the pusher 150 when the brake pedal is actuated.

The characteristics of the springs 110 and 121 are such that the contact force between the pusher 150 and the guide surface 172 is significantly reduced in the initial portion of the travel range of the pusher 150 (most often used in daily braking situations) And is further arranged to be distributed between the upper and lower portions of the guide surface, which significantly reduces the wear energy per unit contact area between the components over the service life of the power transmission device 1.

The control rod 140, which is urged by the brake pedal, urges the pusher 150 against the spring 23 in the cylinder 22 to activate the braking system. Sleeve 160 and springs 110 and 121 essentially maintain their position so that the deviation of the angle between axis X1X1 and axis XX only slightly changes so that bowl 141 pivots very little.

Fig. 4 shows a braking situation. The mass MP of the brake pedal (not shown) is applied at the link point between the pedal and the control rod 140. Between the reaction from the horizontal component Fh of the input force F and the pressure Ph of the hydraulic pressure source generated in the module 1 in combination with the counter reaction force Fs by the return spring 23, .

The pusher 150 and all the components therein, the control rod 140 and the pedal are positioned such that when the driver accidentally releases his or her foot from the pedal and accidentally releases the brake pedal, (To the right) toward their respective rest positions at high speed under the influence of the oil pressure Ph and the force Fs of the spring 23 until they come into contact with the bottoms 27 of the springs 21.

Fig. 5 shows the instantaneous position of the elements of the transmission device 1 immediately after contact. Equilibrium is lost; The oil pressure in the chamber 24 and the thrust of the spring 23 vigorously push back the pusher 150, which urgently moves the control rod 140 to the right while driving the brake pedal. The bowl 141 is spaced from the cup 153 due to the momentum communicated by the pusher 150 which is a stop for the bottom 27 by itself.

In this shifting step, the bowl 141 presses the sleeve 160 back by first compressing the spring 110; The sleeve is supported against the floating ring 120 and then compresses the return spring 121. The backward movement of the sleeve 160 and the compression of the springs 110,120 partially absorb the kinetic energy which slows down the end of travel of this movement by slowing and mitigating the movement of the rod 140 and the brake pedal.

Throughout the spring compression phase, the velocity of the moving element is reduced sufficiently below that of its normal velocity. The decelerating force induced in the system is thereby reduced and the stress experienced by the various components of the module is also reduced. Noises caused by the impact between the components are also reduced.

The return spring 121 is released from the end position of the travel position of the double backward movement step (the control rod 140 having the pusher 150 and the sleeve 160), and the return spring 121 is returned to the cup 153 The sleeve 160 is pressed back via the floating ring 120 and the rod 140 to fit the bowl 141 again. This return movement may involve one or more small "bounce" movements between the bowl 141 and the cup 153 / pusher bottom 151; These movements will be buffered very quickly by friction so that at the end of these movements, the elements are located in the position of FIG.

6 shows a variant of a transmission device 1 having a buffering element 180 in the form of a friction element between the sleeve 160 and the pusher 150. [ During the spring 110, 121 compression phase, in the event of a sudden release of the brake pedal, a portion of the kinetic energy of the moving component is dissipated into the buffer element 180, which increases the overall buffering effect of the system.

During decompression of the springs 110 and 121 a portion of the energy stored in the springs 110 and 121 also partially flows into the buffer element 180 when components return to their normal rest position in the pusher 150 Or completely dissipated. The return speed of the component is thus reduced, thereby avoiding any tendency for the component to return to a position where it may reactivate the brake system, resulting in unwanted, or even dangerous, braking action.

7 shows another modification of the transmission device 1, and the same elements as those of the previous embodiments will not be described in more detail with the same reference numerals.

This variant includes a shoulder 255 having a front portion 252a for receiving sleeve 160 and a rear portion 252 of large diameter defining a shoulder 255 between the front and rear portions thereof, The shape of the bore 252 of the bore 250 is different. The floating ring 120 is movable within the rear portion 252b by being urged against the shoulder 255 by the return spring 121. [

The length of the forward portion 252a is greater than the length of the sleeve 160 to leave gaps 130 and 131 relative to the bottom 251 and the floating ring 120. [ This embodiment of separating the action of the centering spring 110 from the action of the return spring 121 causes the return spring 121 to be dimensioned only according to the effect of absorbing the impact of the backward movement of the control rod 140 . This increases the buffering effect of the spring 121 and the energy that may be stored to make it more effective in the event of a sudden release of the brake pedal without interfering with other functions performed by the spring 110.

1: transmission device 2: control module
21: housing 22: cylinder
23: spring 24: cylinder chamber
25, 26: hydraulic orifice / connection 27: housing bottom
3: partition 31: orifice
6: sensor 7: return spring
100: return and buffer device 110: centering spring
120: floating ring 121: return spring
122: annular stop portion
130: clearance between the front portion of the sleeve 160 and the bottom portion 151
131: clearance between the sleeve 160 and the ring 110
140: Control rod 140a: Front end
140b: rear end portion 141: spherical bowl
141a: spherical front surface 141b: planar rear surface
150, 250: pusher 151, 251: bottom
152, 252, 252a, 252b: bore 153: spherical cup
154: groove 160: cylindrical sleeve
161: inner collar 162: inner groove
171: guide zone 172: guide zone
180: buffer element 255: shoulder
EM: Engine compartment H: Passenger compartment

Claims (8)

And a mobile transmission device for linking the control module to the brake pedal,
A control rod of the axis X1X1 linked to the brake pedal; And
- a piston-shaped pusher, linked to said control module and guided in the cylinder of the shaft (XX);
A piston-shaped pusher linked to an end of the control rod by a ball joint and returned to the thrust of the control rod by a return spring;
Said pusher having a cup-shaped support surface for freely rotatably / pivotally receiving a ball of said control rod,
The system is characterized in that the transmission device (1)
And a return and buffer device (100) between the control rod (140) and the pusher (150,250), the device (100) being supported by the pushers (150,250)
A. a spherical bowl 141 at an end 140a of the control rod 140 and having a spherical front support surface 141a and a planar rear surface 141b perpendicular to the axis X1X1 of the rod 140;
B. Slides in the bores 152 and 252 of the pushers 150 and 250 and is supported against the rear surface 141b of the spherical bowl 141 perpendicularly to the axis XX of the pushers 150 and 250 A sleeve 160 that freely surrounds the control rod 140;
C. supported within the pusher 150 and 250 relative to the floating ring 120 and against the centering sleeve 160 to urge the centering sleeve and move the spherical bowl 141 and the control rod 140 A centering spring (110) that tilts the weight of the control rod (140) toward the axis (XX) of the pusher (150);
D. A return which is received in the bores 152, 252 of the pushers 150, 250 and is supported against the floating ring 120 as well as the annular stop 122 tightly connected to the pushers 150, Includes a spring (120);
E. In the mounting position of the electric device (1), the floating ring (120) is separated from the sleeve (160) by a clearance (131). The method according to claim 1,
The centering spring 110 and the return spring 120 mounted in series between the sleeve 160 and the annular stop 122 are positioned such that at the time of equilibration the floating ring 120, Is dimensioned to be separated from said sleeve (160) by means of a sleeve (171). The method according to claim 1,
- said pusher (250) has a bore (252) formed therein with a forward portion (252a) defining a shoulder (255) and a rear portion (252b) of greater diameter;
The floating ring 120 is movable within the rear portion 252b and is supported against the shoulder 255 by the thrust of the return spring 120;
The length of the front part 252a which slidably receives the sleeve 160 is such that the free clearance 131 is left between the sleeve 160 and the floating ring 120 and thus the shoulder 255 Is greater than the length of said sleeve (160) to support said sleeve (160). The method according to claim 1,
Characterized in that the sleeve (160) comprises an inner collar (161) on which both the planar rear surface (141b) of the bowl (141) and the centering spring (110) are supported. The method according to claim 1,
Wherein the centering spring (110) is a spiral spring or a stack of a beveled washer, and the return spring (120) is a helical spring surrounding the control rod (140). The method according to claim 1,
Characterized in that the annular stop (122) is a split ring engaged in the groove (154) of the bore of the pusher (150). The method according to claim 1,
And a buffer element (180) interposed between the pusher (150) and the bore (22) to absorb a portion of the kinetic energy of the pusher (150) sliding within the bore (22) Braking system. 8. The method of claim 7,
Characterized in that the buffer element (180) is a friction element incorporated within the pusher (150) and / or in the bore (22).

Images