FR2462316A1 - HYDRAULIC BRAKE TRAILER EQUIPMENT - Google Patents

Abstract

HYDRAULIC TRAILER BRAKING EQUIPMENT WITH A COUPLING FOR CONNECTION TO A HYDRAULIC CIRCUIT OF A TRACTOR VEHICLE, AT LEAST ONE HYDRAULIC ACCUMULATOR FOR EMERGENCY BRAKING, A SWITCHABLE DISTRIBUTOR TO THE EMERGENCY BRAKING POSITION AND POSGING MEANS OF THIS . THE DISTRIBUTOR 5 INCLUDES A CONTROL UNIT 13 ACTING IN CONNECTION WITH A HYDRAULIC COUPLING 4. IT IS SWITCHED BY THE CONTROL UNIT 13 WHEN A LINE 2 CONNECTING THE TRAILER BRAKING EQUIPMENT 1 IS OPENED OR WHEN DISCONNECTING.

Description

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  The present invention relates to pressurized fluid trailer braking equipment, comprising a coupling for

  connection to a pressurized fluid circuit of the tractor vehicle.

  at least one pressure fluid accumulator for emergency braking, a switchable distributor in the emergency braking position and means for disengaging the

emergency braking.

  Hydraulic trailer braking equipment of this type

  guarantee, in addition to the usual main braking, controlled

  by the towing vehicle, emergency braking of the trailer by battery-operated switching in case of

  inadvertent separation of the trailer and the towing vehicle.

  For switching on the emergency braking of the unwanted trailer, the French Patent No. 1,376,689 describes the mounting of a distributor that a tear cord, actuated from the towing vehicle, switches to the emergency braking position . A disadvantage of this solution lies in the fact that

  switching to the emergency brake position is carried out

  if the tear cord has actually been attached to the

  trailer when the latter is coupled to the tractor vehicle.

  tor. The detached trailer is not braked if this operation has been neglected. The subject of the invention is a hydraulic braking equipment

  of the type previously described, guaranteeing a

  on the emergency braking of the inadvertently detached trailer

  independently of maneuvering means to be connected further

  when coupling the trailer.

  According to an essential characteristic of the invention, the dis-

  equipment tributor comprises a control member acting in connection with a pressurized fluid coupling; and said

  distributor is switchable by the control member, when

  opening of a connecting pipe of the braking equipment

  trailer or uncoupling.

  The invention presents in particular the following advantages

  the control member, acting in conjunction with a hand

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  hydraulic safety equipment and on the other hand with a

  braking equipment of the trailer, switchable to an emergency braking position, ensures switching on the

  emergency braking of the accidentally separated trailer of the vehicle

  tractor, said imposed and reliable control being produced solely according to the release of the safety coupling by the action of a traction, without any additional means of

  control to be connected when coupling the trailer.

  The control member makes it possible to constitute a simple and highly safe trailer braking equipment,

  in conjunction with a switchable distributor on a braking position

  rescue swimming against or under the action of a spring.

  In the case of the use of a switchable distributor in the emergency braking position against the action of a spring, the detent device according to the invention guarantees, in connection with a control member comprising a distributor pushbutton, an emergency braking position maintained with certainty and capable of being disengaged

  hydraulically, when coupling the trailer, or mechanically

  when the trailer is uncoupled.

  As a result of its operation in connection with the latching device and a non-return valve assigned to a release accumulator, the proposed operating lever for the mechanical release of the emergency brake position first guarantees the

  release of the interlocked emergency brake position of the disc

  tributor, then the connection of the brake line, the charge of which

  hydraulic emulator is locked, to a release accumulator to reduce the pressure and release the braking position of

  help; and when the lever is at rest, the lock of the battery

  release emulator for the brake line and the possibility

  repeated passage on the emergency braking position by trac-

  on the safety coupling, the trailer being uncoupled.

  When using a switchable dispenser on the posi-

  emergency braking under the action of a spring, the proposed control member, made in the form of a dispenser push-button

  and acting in connection with one of the two shutters of a coupler-

  safety device, guarantees switching to the braking position

  emergency swimming according to the closing movement of said obtura-

  when uncoupling, the emergency braking position may be disengaged, when the trailer is coupled, by the forced return of the distributor to a basic position, that the

  open shutters of the safety coupling engaged maintain-

  through the dispenser pusher, or when the

  trailer is uncoupled, by the impulse maneuver of a

  fart of no return assigned to a connectable release accumulator

to the brake line.

  The control member, in the form of a push button

  tributor, is advantageously reunited with the distributor and the

  security coupling to form a constructive unit. Lemon-

  proposed floor of the dispenser and its pusher in a blind hole

  staggered cylindrical body offers, in addition to the advantages of

  the possibility of elastically mounting this unit in the

  of a manifold, in a way that is extremely suitable for

  mating and uncoupling.

  The manifold furthermore advantageously comprises a coupling with appropriate bores for the brake line, a connection with appropriate holes for the hydraulic accumulator and the nonreturn valve assigned to the latter, and a connection with bores.

  suitable for the release accumulator and the non-return valve.

  back, assigned to the latter and operated by a pusher. This gives a compact construction unit, containing the main control devices of the trailer braking equipment, easily mounting on the trailer and suitable for clearance

  simplified position of the emergency braking position of the disabled trailer.

  coupled, in particular on agricultural machinery.

  Other features and advantages of the invention will be

  better understood using the detailed description below of a

  embodiment and the accompanying drawings in which Figure 1 shows the diagram of a hydraulic trailer braking equipment; FIG. 2 represents the diagram of a modified embodiment.

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  and simplified hydraulic trailer braking equipment; and FIG. 3 is the longitudinal section of a distributor joined to a hydraulic coupling for trailer braking equipment.

according to figure 2.

  The hydraulic trailer braking equipment 1 shown in Figure 1 is connected by a hydraulic hose 2 to a head 3 of a hydraulic safety coupling 4, mounted on a tractor vehicle not shown, and by the safety coupling 4 has a

  hydraulic braking system of the towing vehicle.

  The trailer braking equipment 1 comprises a distributor with a basic position, held by a spring 26 and in which the hose 2 is connected on the one hand to a brake line 6 and on the other hand to a hydraulic accumulator 8 , by a non-return valve 7, mounted in the dispenser and opening in the direction

  flow rate of the brake pressure applied by the hose 2.

  The brake pipe 6 is connected to a cylinder 9, which actuates

  trailer brakes not shown.

  A non-return valve 11, unlockable against the action of a spring 10 and the pressure in the brake pipe 6, connects this

  last to a clearance accumulator 12.

  A control member 13, acting in connection with the safety coupling 4, switches the distributor 5 to an emergency braking position, on which the hose 2 is isolated from the brake line 6 and the hydraulic accumulator 8, and the brake line

  6 is connected directly to the hydraulic accumulator 8, with

the check valve 7.

  The control member 13 is constituted in this example of reali-

  by a pusher 14 distributor, mechanically connected by the hose 2 to the head 3 of the safety coupling on the trailer, actuated against the action of a spring by a tractive force acting on the safety coupling 4 and lockable in the emergency brake position of the distributor 5 by a

latching device 15.

  The latching device 15 comprises a pin 17, applied by a spring 16 to the pusher 14 and acting in connection with a

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  stop 18, formed on the pusher 14 and that a displacement of this

deny allows to cross.

  The latching pin 17 is connected to the piston 19 of a hydraulic cylinder 20, which translates it, the spring 16 bearing on the one hand on the piston 19 and on the other hand in the cylinder 20. The applied braking pressure to the trailer braking equipment 1 charges the piston 19 via a chamber 21

  hydraulic cylinder 20, delimited by the piston 19, and a

  duit 22 connected to the chamber 21; a determined braking pressure translates the piston 19, against the action of the spring 16, and moves the

  pin 17 out of its latching zone.

  The free end of the latching pin 17 acts in conjunction

  sound with a lever 23, pivoting about a fixed center of rotation, moving the pin 17 against the action of the spring 16, the way

  trailing coupling and regardless of the brake pressure

  applied to the chamber 21, and thus clearing the pin 17 of

its latching position.

  When the pin 17 is moved from its latching zone, the

  lever 23 also acts in conjunction with a pusher 24, which

  rust the check valve 11 assigned to the accumulator of degeneration

  12, when the distributor 5 is switched to the basic position, and connects the release accumulator 12 to the brake line 6. The hydraulic accumulator 8 is connected to a pressure switch 25 which, under a pressure determined in the accumulator, closes an electrical signaling circuit connected to a corresponding circuit

of the towing vehicle.

  The operation of the hydraulic brake equipment of

  Trailer 1 according to Figure 1 is the following.

  The hydraulic trailer braking equipment 1 is

  in the normal operating position, with the trailer

  to the towing vehicle. It is connected to the hydraulic braking circuit of the towing vehicle by the safety coupling 4 engaged and the electrical signaling circuit of the trailer is

  connected to the corresponding signaling circuit of the towing vehicle.

I

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  The pin 17 not snapped is applied by the spring 16 to the pusher 14 of the distributor 5 held by the action of a spring in its basic position; the hose 2 is connected on the one hand to the brake line 6 by the distributor 5 and on the other hand to the hydraulic accumulator 8 by the non-return valve 7, so that a braking pressure controlled by the The hydraulic brake equipment of the towing vehicle is applied by the distributor to the brake line 6 and the brake cylinder 9, for braking, and by the non-return valve 7 to the hydraulic accumulator.

8, for charging.

  The hydraulic accumulator 8 is loaded, as a result of braking thoroughly carried out before the start of the journey, and protected by the valve

  of non-return 7 against a return flow in the absence of pressure

  in the hose 2 and the brake line 6. The pressure switch 25

  connected to the hydraulic accumulator 8 interrupted the signal

  electrically under the action of a predetermined minimum charge pressure. The non-return valve It connects the release accumulator 12, under a corresponding load, to the brake line 6 for its discharge, during the brake release phase for example, and the

  protects against the load by the brake line 6.

  As soon as the trailer comes off the vehicle accidentally

  the hose 2 is stretched by the trailer until a pulling force, acting on the safety coupling, switches

  firstly, via the control member 13, the distribution

  5 on the emergency braking position maintained by the

  positive snap 15, then releases the safety coupling 4.

  In the emergency braking position of the distributor 5,

  held by the pin 17 of the latching device 15, the

  xible 2 is isolated from the brake line 6 and the hydraulic accumulator 8, and the brake line 6 is connected to the hydraulic accumulator 8 with bypass of the non-return valve 7, so that the pressure of the hydraulic accumulator 8 is applied to the brake line 6 and that the cylinder 9 provides braking of

rescue of the trailer.

  The operation of the lever 23 makes it possible to clear the position of

  emergency braking as soon as the uncoupled trailer is to be

born in another position.

  The operation of the lever 23 against the action of the spring 16 first releases the pin 17 from its latching position, so that

  under the action of a spring, the distributor 5 passes into its position.

  base, on which the brake line 6 is connected to the

  flexible 2, isolated on the head 3 unobstructed coupling, and the

  non-return fart 7 isolates the brake line 6 from the accumulator

  hydraulic 8 when the pressure decreases in said pipe.

  The continued operation of the lever 23 allows, through the

  the pusher 24, to bring the non-return valve 11 into

  the open position, against the action of the spring 10 and the pressure

  in the brake line 6, so that the latter is connected to the release accumulator 12, its pressure decreases and the emergency braking position is released. Spring 16 brings back

  the lever 23 released in its basic position and the trailer disengaged

  plé can be moved with the brakes just loosened.

  A traction on the control member 13 makes it possible to restore the

  emergency braking position as soon as the trailer occupies the posi-

desired.

  As soon as the trailer is again connected mechanically, hydraulically

  liquefied and electrically to a towing vehicle, a full braking, carried out before the start of the journey, first produces a load of the hydraulic cylinder 20 and consequently a hydraulic release of the emergency brake lock position of the distributor 5, so that the latter is switched by a spring to its basic position and the braking pressure in the pipe 6 is applied by the non-return valve 7 to the hydraulic accumulator 8 to

his load.

  When the charge of the hydraulic accumulator 8 is sufficient

  the pressure switch 25 interrupts the electrical signaling circuit.

  and indicates that the vehicle is ready for the trip.

  During the next phase of brake release, the accumula-

  12 is automatically connected by the nonreturn valve to the brake line 6 without pressure, for its discharge,

  and the normal operating position, previously described, of the equi-

  braking position of the trailer is restored.

  The hydraulic trailer braking equipment according to Figure 2 is connected by a hydraulic safety coupling 4a mounted on the trailer, and a hose 2a connected to a head 3a of

  the safety coupling 4a directly or by a second

  safety release by a higher traction at a lower

  hydraulic braking system of a tractor vehicle not

sented.

  The safety coupling 4a, via an organ

  13a acts in conjunction with a distributor 5a which, when

  that the safety coupling 4a is engaged, is maintained in its basic position by the control member 13a, against the action of a

  spring 26a and under the action of a shutter 35 of one of the two keys

  pets of non-return of the safety coupling 4a kept in the open position and, when the coupling head 3a is disengaged and the non-return valves of the safety coupling 4a are kept in the closed position, goes into the position

  emergency braking under the action of the spring 26a.

  In the basic position represented by the distributor 5a, the hose 2a is connected by the latter to the brake line 6 and

  connected to the cylinder 9, and by the non-return valve 7 to the accu-

  8 hydraulic emulator, as previously described using

of Figure 1.

  In the emergency braking position, the safety coupling 4a being isolated at the output, the distributor 5a connects the brake line 6 to the hydraulic accumulator 8 with a bypass

check valve 7.

  A check valve lla, unlockable against the action of the spring 10 and the pressure in the brake pipe, connects the

  brake line 6 as in the case of Figure 1 to the accumula-

  12, or under the preponderant action of a

  in said accumulator, either mechanically via a pusher 24a, whose free end carries a mushroom head

2 4 6 2 3 1 6

  27 and that is operated as a punch switch.

  The hydraulic accumulator 8 is, for the signaling of its state of charge, connected in the manner previously described to the pressure switch

  which controls an electrical signaling circuit.

  FIG. 3 represents an exemplary embodiment of the organ

control 13a.

  The operation of the hydraulic brake equipment of

  Trailer according to Figure 2 is the following.

  Hydraulic trailer braking equipment is represented

  in the normal operating position, the trailer being coupled

  mechanically, hydraulically and electrically to a vehicle

not shown.

  The open non-return valves of the safety coupling 4a keep the distributor 5a in its basic position, via the control member 13a and against the action of the spring 26a. In this position, a pressure controlled by the hydraulic braking circuit of the towing vehicle is applied by the distributor Sa to the brake line 6 and to the cylinder of

  brake 9, for braking, and by the non-return valve 7 to the accu-

  hydraulic 8 emulator, for charging and recharging.

  The hydraulic accumulator 8 is loaded and a pressure in the latter, sufficient for the emergency braking, maintains the

  switch 25, connected to the accumulator 8, in an interrupted position

  electrical signaling circuit.

  The release accumulator 12 is connected, under the action of its pressure and by the non-return valve 11, to the brake line 6

  without pressure, for its discharge, and protected by the check valve

  He backs up against a load through the 6-fed brake line.

  As soon as the trailer comes off the vehicle unexpectedly

  tractor and the head 3, connected to the hose 2a, is detached from the

  4a, by pulling the hose 2a extended by the trailer which moves away, the check valves of the safety coupling 4a pass into their closed position, the spring 26 switching to the emergency braking position the distributor 5a, acting through the control member 13a with a

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  of the two check valves of the safety coupling 4a. This

  last being isolated at the exit, the brake line 6 and the cylinder

  9 are, as previously described with the aid of Figure 1, connected to the hydraulic accumulator 8, with bypass of the non-return valve 7, and loaded by the pressure of the accumulator

8 for emergency braking.

  As soon as the uncoupled trailer has to be moved to another position, an impulse operation of the pusher 24a makes it possible to

  release the emergency braking position, thus enabling the

  connection of the release accumulator 8 to the brake line 6 by the non-return valve 11a, held in the open position by the pusher 24a, the reduction of the brake pressure and the

translation of the trailer.

  Repeated switching on the emergency braking, the trailer being uncoupled, is not provided in the simplified trailer braking equipment according to Figure 2, and intended in particular for agricultural vehicles. After the release of the emergency braking position, it is therefore necessary to immobilize the uncoupled trailer

  using a parking brake, not shown.

  As soon as the trailer is again coupled to the vehicle

  5a, the distributor 5a returns to its basic position against the action of the spring 26a, when engaging the safety coupling 4a. The normal operating position described above is established when a full braking, performed before the start of the journey, charges the hydraulic accumulator 8 and the pressure switch 25, actuated according to a determined minimum pressure in the accumulator,

  interrupts the electrical signaling circuit.

  During the following braking phase, the non-return valve 11a, unlockable by the pressure in the disengagement reservoir 12, makes it possible to connect the latter to the brake line 6 without pressure.

and unload it.

  FIG. 3 represents a distributor Sb suitable for realizing

  trailer braking equipment according to Figure 2.

  The distributor 5b has a cylindrical body 28 with a

  blind hole 29 stepped outward.

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  The blind hole 29 opens into a safety coupling 4b,

  which comprises a head 30, sealingly attached to the cylindrical body

  28, and a sleeve 31, guided in translation and with sealing on the head 30, for the housing of the second head 32, connected to the hose 2a. The two coupling heads 30, 32 each comprise, on the output side, a seat 33, 34 which, with a shutter 35, 36 loaded by spring in the direction of the outlet, forms a non-return valve

33, 35 or 34, 36.

  The shutters 35, 36 are guided in translation, by means of a

  long, in the form of a pusher, in the coupling heads 30, 32 with a radial clearance, held in the open position against the action of a spring and by mutual contact, when the safety coupling 4b is engaged, and held in the closed position by the action

  of a spring, when the safety coupling 4b is released.

  The groove 37 of the head 32 and the balls 40, arranged with a

  radial clearance in the sleeve 31, allow coupling with clutch-

  the head 32 connected to the hose 2a. The balls 40 are held in their latching position by a second sleeve 39, guided in translation on the sleeve 31 and abutting on the latter

  under the action of a spring 38 bearing on said sleeve 31.

  A relative translation of the sleeves 31 and 39, against the action of the spring 38, brings the balls 40 in their latching position

or away from them.

  A seat 41 of the valve is formed on the bottom of the blind hole 29 and acts in connection with a shutter 42, actuated by the shutter 35 of the safety coupling 4b, via a valve member.

  13b, so that the shutter 42 closes when the latch

  safety device 4b is engaged and opens when said coupling

is clear.

  The control member 13b is constituted by a pusher 43 of the distributor, which is guided in translation in a sleeve 44, fixed in an axially ribbed zone of the section of larger diameter

blind hole 29 stepped.

  One end of the pusher 43 engages with play in the coupling

Security 4b. A spring 45, bearing on one side on the sheath 44 and on the other side on the pusher 43, applies this

  last on the extension of the shutter 35 shaped pusher.

  The second end of the pusher 43 acts elastically in connection with the shutter 42, which has a limited translation on the pusher 43 via a tubular extension, having two oblong holes axially facing and a stud 46, which passes radially. the pusher 43 and engages in the oblong holes. A spring 47, supported on one side on the shutter 42 and on the other on the pusher 43, brings the shutter 42 in the closed position on the seat 41, when the safety coupling 4b is engaged, and in the open position on the stud 46, when

  safety coupling 4b is released.

  A rod-like extension connects the shutter 42 to a piston 48, guided in translation and with sealing in the smaller diameter section of the blind hole 29 stepped. The chamber delimited by the bottom and the piston 48 is connected by a channel in the piston 48 and the shutter 42 to the chamber constituted by the larger diameter section of the stepped blind hole 29 and defined by the shutter

42.

  The cylindrical body 28, connected to the safety coupling 4b, slides in a bore 49 of a manifold 50 and is applied by the

  spring 38 on a stop 52 secured to the manifold, through

  of a support 51, fixed on the manifold 50 and bearing on

  the outer sleeve 39 of the safety coupling 4b.

  The stop 52 is formed on a wear part, which closes with venting the bore 49 on the opposite side to the coupling of

security 4b.

  The manifold 50 has a connection 53 for the brake line 6, which is connected to the larger diameter section of the blind hole

  stepped 29, sealed to bore 49.

  A non-return valve 7b, a spring closes towards the connector 53, and a bore 54 connect the connector 53 to a connector 55

for the hydraulic accumulator 8.

  The bore 54 and a bore 56 further connect the connector 55,

2 4 6 23 1 6

  with sealing relative to the bore 49, at the smaller diameter section of the stepped blind hole 29, delimited on one side by

  the piston 48 and the other by the shutter 42.

  The manifold 50 finally comprises a connector 57 for the clearance accumulator 12. A non-return valve 11b, a spring 10b closes towards the connector 57, connects the latter to the larger diameter section of the stepped blind hole 29 , with sealing by

relative to the bore 49.

  The check valve llb is unlockable by a press

  in the release accumulator and mechanically by a

  evening 24b, sliding with sealing in a bore of manifold 50

  and operated as a key, in connection with the spring 1Ob.

  The operation of the distributor 5b according to FIG.

  efore. The distributor 5b is shown in its normal operating position, on which the safety coupling 4b engaged establishes a connection with the hydraulic braking circuit of a towing vehicle. The shutters 35 and 36 of the non-return valves 33, 35 and 34,

  36 of the safety coupling 4b are kept in the open position.

  verture with mutual support. The control member 13b, applied by the

  spring 45 on the shutter 35, occupies its limit position direc-

  41 of the valve seat 41 and the shutter 42, hydraulically balanced.

  only by the piston 48 which is assigned to it, passes in its position

  closing on spring action 47.

  Braking pressure controlled by the brake system

  hydraulic system of the towing vehicle can thus be applied to

  brake line 6 connected by the safety coupling 4b, the larger diameter section of the stepped blind hole 29 and the connection 53 which is connected thereto. The hydraulic accumulator 8 connected to the connection

  can be recharged by the non-return valve 7b and the bore 54.

  In case of untimely detachment of the trailer of the towing vehicle, the safety coupling 4b and the cylindrical body 28 which is connected thereto translate first under the action of traction

  exerted on the hose 2a, and against the action of the spring 38, up to.

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  the balls 40 come out of the latching groove 37 and the coupling head 32 is released from the sleeve 31, the shutters 35

  and 36 then closing in the coupling heads 30 and 32.

  The control member 13b, applied by the spring 45 to the shutter 35, then moves to a limit position with respect to the safety coupling 4b, on which the shutter 42, driven in the manner of a trailing link and applied to the pin 46 by the spring 47, is held in the open position and the brake pipe 6 connected to the connector 53 is loaded, via the

  step blind hole 29 and the bore 56, by the pressure of the accu-

  hydraulic emulator 8 connected to the connector 55, for emergency braking. As soon as the uncoupled trailer has to be brought into another position, an impulse maneuver of the pusher 24b enables

  to release the emergency braking position. The accumulation accumulator

  12 connected to the connector 57 is connected to the brake pipe 6 by the non-return valve, opened by the pusher 24b against the action

  the spring 1Ob, the stepped blind hole 29 and the connector 53; the pressure

  sion decreases in the brake line 6 and the trailer can be

  translated with the brakes released.

  The distributor 5b according to FIG. 3 is suitable for simplified trailer braking equipment according to FIG. 2. A repeated switching on emergency braking is not provided for the uncoupled trailer, which must therefore be immobilized by the parking brake.

  after the release of the emergency braking position.

  A variant of the dispenser 5b is conceivable for the applications

  cations in which repeated switching to the position of

  emergency braking is desired: a pusher 24b,

  connected with the control member 13b, close the closure

  42 when the check valve Ilb is open mechanically.

  As soon as the trailer is again coupled to a towing vehicle, the shutter 42 moves to its closed position when the safety coupling 4b engages and the clearance accumulator 12 is connected for discharge to the driving line. brake 6 without pressure, by the nonreturn valve 1lb, unlockable by

  the pressure in said accumulator, and the section of stronger di-

meter of the blind hole 29.

  The normal operating position described above is established when a full stop, made before the start of the journey, has loaded the hydraulic accumulator 8 by the non-return valve 7b and

the bore 54.

  Of course, various modifications may be made by those skilled in the art to the principle and to the devices which have just been described solely by way of nonlimiting examples, without

depart from the scope of the invention.

Claims (6)

claims   1. Pressurized fluid trailer braking equipment, comprising a coupling for connection to a pressurized fluid circuit of the towing vehicle, at least one pressurized fluid accumulator for emergency braking, a switchable distributor in the braking position emergency device and means for disengaging the emergency braking position, said equipment being characterized in that: a) the distributor (5, 5a or 5b) comprises a control member (13, 13a, 13b) acting in conjunction with a fluid coupling - under pressure (4, 4a or 4b); and b) the distributor (5, 5a or 5b) is switchable by the control member (13, 13a or 13b) when opening a pipe (2, 2a) for connecting the equipment (1 , a) braking   the trailer or when uncoupling.   Pressurized fluid trailer braking equipment according to claim 1, characterized in that the fluid under pressure is a hydraulic fluid.   3. Hydraulic trailer braking equipment according to   2, characterized in that: a) the control member 13 is a pusher (14) distributor,   connected directly or by a hydraulic line (2) to a   hydraulic safety coupling (4); b) under the action of a traction force exerted on the safety coupling and against the action of a spring (26), the pusher (14) moves the distributor (5) to a position of emergency braking in which a brake line (6) is isolated from the safety coupling (4) and connected to a hydraulic accumulator (8); c) the distributor (5) is held in the emergency braking position by a detent device (15); and d) the latching device (15) comprises a lever (23) which   allows to release the position of emergency braking.   Hydraulic trailer braking equipment according to claim 3, characterized in that: 24623 16   a) the latching device (15) comprises a spindle (17)   a spring (16) applies to the dispensing pusher (14)   tor; b) the pusher (14) has a stop (18), which acts in connection with the detent pin (17) and can be reached when the distributor (5) is brought into the emergency braking position; c) the spindle (17) meshes with a free end a lever (23)   pivoting around a fixed center and which, like a training   trailing and against the action of the spring (16), allows to move the pin (17) of its snap zone and to release the emergency braking position of the distributor (5); d) when the pin (17) is moved away from its latching zone,   the lever (23) acts in conjunction with a pusher (24) which releases   rust a non-return valve (11); e) the non-return valve (11) is assigned to a release accumulator (12) connected to the brake line (6) and, when the pusher (24) is not actuated, is unlockable according to the pressure in said accumulator (12) and against the action of a spring (10) and the pressure in the brake line (6); f) the detent pin (17) is connected to a piston (19) guided in translation and sealed in a hydraulic cylinder (20); g) the spring (16) is housed in the hydraulic cylinder (20) and bears on one side on the piston (19) and on the other on the cylinder; and h) the piston (19) is loaded by the brake pressure controlled by the towing vehicle, via the safety coupling (4) and a pipe (22), and movable under the action   determined braking pressure against the action of the res- spell (16).   5. Hydraulic trailer braking equipment according to 2, characterized in that:   a) the control member (13a, 13b) acts in conjunction with an obtura-   driver (35) of a non-return valve of the safety coupling (4a, 4b); b) the control member (13a, 13b) is applied by a spring (26,) on the shutter (35), whose movement switches it to the open or closed position of the distributor (5a, Sb) ; c) the closing movement of the shutter (35) produced by the   uncoupling, switch the distributor (5a, 5b)   the control member (13a, 13b) to an emergency braking position in which a brake line (6) is connected, when closing the shutter (35), to a   hydraulic accumulator (8) with deflection of a non-return valve   return (7a, 7b) closing according to the pressure in the   accumulator; d) the movement of the shutter (35) towards the open position, produced by the coupling, switches the distributor (5a, 5b), via the control member (13a, 13b), on the basic position in which the hydraulic accumulator (8) is connected to the brake line (6) by the non-return valve   (7a, 7b) closing as a function of the pressure in the accumula-   the brake pipe (6) is connected by the safety coupling (4a, 4b) to the braking circuit of the towing vehicle and the emergency braking position is disengaged;   (e) when the safety coupling (4a, 4b) is disengaged, the posi-   emergency braking circuit is disengaged from a release accumulator (12) connected to the brake line (6) by a mechanically unlockable check valve (11a, 11b); f) the non-return valve (11a, 11b) is actuated by means of a pusher (24a, 24b), against the action of a spring (10) and in the manner of a pusher; and g) when the pusher (24a, 24b) is not actuated, the non-return valve (11a, 11b) is unlockable as a function of the pressure in the release accumulator (12), against the action   spring (10) and pressure in the brake line (6).   6. Hydraulic trailer braking equipment according to   5, characterized in that: a) the distributor (5b) and the control member (13b) are fixed with sealing in a blind hole (29) of a cylindrical body (28), staggered outwards, and the safety coupling (4b) is sealingly attached to the open side of the body (28) via a coupling head (30); b) the control member (13b) is a pusher (43) of distributor, guided in translation in a sleeve (44) fixed in an axially ribbed zone of the larger diameter section of the stepped blind hole (29), a end of said pusher (43) being applied to the shutter (35) of the safety coupling (4b) by a spring (45) bearing on the sleeve (44) and the pusher; c) the distributor (5b) comprises a seat (41) formed on the bevel of the blind hole (29) and a shutter (42) acting elastically in connection with the pusher of the dispenser; d) the shutter (42) is guided with a limited translation on the   pusher (43) of the dispenser, through a prolongation   tubular arrangement with axial oblong holes and a gou-   jon (46) which passes radially through the pusher (43) and engages in said elongated holes, is applied by a spring (47) to the seat (41) when the safety coupling (4b) is engaged, and maintained in opening position on the stud (46) when the safety coupling (4b) is disengaged; e) the safety coupling (4b) has a sheath (31) in   which balls (40) are housed with a radial clearance and   snap a coupling head (32);   f) the balls (40) are held in their engaged position   by a second sleeve (39), guided in translation on the sleeve (31) and applied on an abutment thereof by a spring (38) bearing on the sleeve (31), and leave their latching position, against the action of the springs (38) during the operation of one of the two shafts (31, 39); g) the cylindrical body (28) slides in a bore (49) of a manifold (50) and is applied to an abutment (52) thereof,   under the action of the spring (38) and through a   port (51) fixed on the manifold (50) and supported on   water (39); h) the manifold (50) has a coupling (53) for the brake line (6) and connected to the larger diameter section of the stepped blind hole (29), sealing with respect to the bore (49) ; i) the manifold (50) comprises the nonreturn valve (7b) assigned to the accumulator (hydraulic (8) and connected on the one hand to the connector (53) and on the other hand, via a bore (54) at a connection (55) for the hydraulic accumulator (8) j) the connection (55) for the hydraulic accumulator (8) is connected   through the bore (54) and a bore (56), with sealing against   port to the bore (49) at the smaller diameter section of the   step blind hole (29) delimited by the piston (48) and the obturator   rator (42); and k) the manifold (50) comprises the nonreturn valve (11b) assigned to the relief accumulator (12) and connected, sealed with respect to the bore (49), on the one hand to the section diameter of the stepped blind hole (29) and on the other hand to a   connection (57) for the release accumulator (12).