IE20170165A1

IE20170165A1 - A trailer breakaway brake system

Info

Publication number: IE20170165A1
Application number: IE20170165A
Authority: IE
Inventors: Lynch Donal
Original assignee: Innealtoireacht Ui Loinsigh Teo
Priority date: 2016-08-19
Filing date: 2017-08-16
Publication date: 2018-05-30
Also published as: GB2555906A; IE87274B1; GB2555906B; GB201713109D0

Abstract

An interface (10) on a trailer (1) couples oil, pneumatics and electrical supplied from a towing vehicle to the trailer. It includes a pressure gauge (30) to indicate pressure available to emergency brakes (11) from an accumulator (15). The gauge can also indicate available hydraulic pressure from a towing vehicle, and in the braking system generally. An in-line check valve (16) allows charging of oil to the accumulator (15) when a vehicle brakes, but prevents flow from the accumulator except when the breakaway valve (22) is opened. <Figure 2>

Description

‘A Trailer Breakaway Brake System’' Introduction The invention relates to breakaway brake systems for trailers with hydraulic brakes.

It is known to provide brake systems in the form of a mechanical brake with a ratchet akin to a conventional hand brake of a vehicle. The breakaway brake is activated when a cable linking the trailer to the vehicle is pulled as they separate.

It is also known to provide as a breakaway brake an hydraulic system with an accumulator and valves which open if a breakaway occurs, thereby delivering oil under pressure to brakes. For example the switches may be controlled by presence or absence of a 12V electrical supply from the vehicle. In the event of a breakaway this electrical link is broken, and absence of it causes the switches to open.

The invention is directed towards providing an improved breakaway brake system which is more likely to be effective in the event of a breakaway occurring.

Summary of the Invention According to the invention, there is provided a trailer interface to a towing vehicle, the interface comprising: a breakaway valve with a link for connection to a towing vehicle, and being arranged to open during a breakaway caused by pulling of the link to allow flow of oil from an accumulator to trailer brake actuators, and a pressure gauge adapted to indicate oil pressure available from an accumulator to trailer brakes in the event of a breakaway.

In one embodiment, the breakaway valve is a lever valve and said valve link is a cable or chain for connection to a vehicle so that the lever is turned upon a breakaway occurring.

In one embodiment, the interface includes a breakaway coupler for connection to a towing vehicle hydraulic line, and said valve link is arranged to be connected to a towing vehicle hydraulic line or coupler component, whereby upon a breakaway occurring the vehicle hydraulic line disconnects at the breakaway coupler and the link is pulled to open the breakaway valve. -2In one embodiment, the pressure gauge is adapted to be connected to an hydraulic line between the breakaway valve and an accumulator.

In one embodiment, the pressure gauge is arranged to show accumulator pressure available if the breakaway valve is manually opened for testing.

In one embodiment, the interface includes pneumatic and/or electrical couplers.

In one embodiment, the interface comprises a support arranged to mount on the front of a trailer.

In one embodiment, the interface is arranged to allow a user to open the breakaway valve to test pressure in a braking system between the accumulator and the brake actuators.

In one embodiment, the coupler is of a push-fit type to allow re-connection by a user after a breakaway, thereby allowing brakes to be released.

In one embodiment, the interface comprises an auxiliary hydraulic coupler which is different ftom said breakaway coupler and is adapted to receive oil from an auxiliary supply and to direct said supply to an accumulator.

In one embodiment, said auxiliary coupler is adapted to receive a supply from a tractor implement hydraulic circuit.

In another aspect, the invention provides a braking system for a trailer, the braking system comprising an interface of any embodiment, brakes and associated hydraulic actuators, and an accumulator, in which the pressure gauge is connected to an hydraulic line between the accumulator and the breakaway valve, and the breakaway valve is connected to allow supply of oil from the accumulator to the brake actuators.

In one embodiment, the braking system further comprises a one-way valve linking the coupler with the accumulator, to allow flow of oil from a vehicle hydraulic line to the accumulator but to prevent, together with the breakaway valve, escape of oil from the accumulator except when the breakaway valve is open. -3In another aspect, the invention provides a trailer comprising a frame, wheels, and a draw bar, and a braking system of any embodiment.

In a further aspect, the invention provides a method of testing a braking system of a trailer of any embodiment, the method comprising manually disconnecting a vehicle hydraulic line from the interface, manually opening the breakaway valve, and the gauge indicating oil pressure between the accumulator and the brake actuators.

Additional Statements According to the invention, there is provided a trailer interface to a towing vehicle, the interface comprising: a breakaway valve with a link for connection to a towing vehicle, and being arranged to open with pulling of the link to allow flow of oil to trailer brake actuators, and a pressure gauge linked to the breakaway valve to indicate oil pressure available for trailer brakes.

In one embodiment, the breakaway valve is a lever valve and said link is a cable or chain.

In one embodiment, the interface includes a breakaway coupling for connection to a towing vehicle hydraulic line, and said link is arranged to be connected to a towing vehicle hydraulic line.

In one embodiment, the pressure gauge is in an hydraulic line between the breakaway valve and an accumulator.

In one embodiment, the interface includes pneumatic and/or electrical couplers.

In one embodiment, the interface comprises a plate arranged to mount on the front of a trailer. -4In another aspect, the invention provides a trailer interface of any embodiment, wherein the interface is arranged to allow a user to open the breakaway valve to test pressure in a braking system between the accumulator and brake actuators.

In another aspect, the invention provides a trailer comprising a frame, wheels, and a draw bar, and: wheel brakes with hydraulic actuators linked to an accumulator, and an interface of any embodiment connected between the accumulator and the brake hydraulic actuators.

Detailed Description of the Invention The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which :Fig. 1 is a diagrammatic plan view showing a trailer and breakaway braking system; Fig. 2 is a front view showing a coupler interface of the braking system; Figs. 3 and 4 are diagrams showing oil flows during normal use and in the event of a breakaway, respectively; and Figs. 5 and 6 are perspective views of an alternative interface of the invention, in this case with an additional coupler.

Description of the Embodiments Referring to Figs. 1 and 2 a trailer 1 has a frame 2, wheels 3, and a draw bar 4.

A trailer breakaway brake system comprises an hydraulic brake actuator 11 and a brake lever 12 of conventional construction for each wheel 3. Oil is supplied to the actuators 11 by a main hydraulic line 13 linked with a trailer interface 10.

The interface 10 is physically mounted at the front of the trailer 1 and is logically between the towing vehicle hydraulic and electrical circuits on one side and those of the trailer 1 on the other. -5The trailer brake system also has an hydraulic accumulator 15 and an inline check valve 16 linked with the main trailer hydraulic line 13. The accumulator 15 stores oil under pressure, in which the volume of oil stored increases with increasing pressure to which it is charged.

The interface 10 comprises a breakaway coupling 20 for connection to an hydraulic line L of the towing vehicle, for the vehicle to provide oil to the trailer whenever the vehicle brakes are applied. A lever valve 22 has a valve body 35 and a lever 36 linked by a wire cable 21 to the breakaway coupling 20 on the vehicle side. This arrangement is also shown in its physical arrangement in Fig. 2. The lever valve 22 links the accumulator 15 to the line 13 for the hydraulic actuators 11.

As shown in Fig. 2 there are also couplers in the interface 10 for the full range of services to the trailer. These include an electrical coupler 40, and couplers 45 for pneumatics and other conventional services. Moreover, the interface 10 comprises a pressure gauge 30 linked to the accumulator 15, between the accumulator 15 and the breakaway valve 22.

Operation Under normal operation, oil is supplied from the towing vehicle, typically a tractor, through the hydraulic line 13 to the trailer brake actuators 11 whenever the driver applies the brakes in the vehicle. As shown in Fig. 3 the flow of oil is to both the accumulator 15 so that it is charged and also to the brake actuators 11 so that the trailer 1 brakes at the same time as the towing vehicle. In this condition oil pressure is maintained in the accumulator 15 because it is retained by the inline check (one-way) valve and by the closed breakaway valve 22.

The pressure gauge 30 is coupled to the hydraulic line between the accumulator 15 and the valve 22. Therefore it displays the pressure of the oil that is stored in the accumulator, and therefore available to the brakes in the event of a breakaway.

The user may in the beginning and at regular intervals pump the vehicle brakes for several seconds to ensure that the accumulator 15 is sufficiently charged, as indicated by the gauge 30. The gauge 30 indicates what hydraulic pressure is available in the event of a breakaway.

The oil is prevented from leaving the accumulator by means of the check valve 16 and the (closed) lever valve 22. Driving braking pressure is applied by the pressurised oil being fed -6down the line 13 to the brake actuators 11 during driving. This supply of pressurised oil also feeds the accumulator 15.

The pressure of oil in the accumulator side of the circuit is displayed by means of the hydraulic pressure gauge 30 and this allows the operator to ensure that the tractor is providing oil at the correct pressure to the trailer brakes. The interface 10 provides a simple test function to simulate a breakaway situation, by the user disconnecting the coupler 20 and pulling down the lever 36, and then viewing the reading on the gauge 30. This indicates the hydraulic pressure in the line from the accumulator 15 to the brake actuators 11.

Referring to Fig. 4, in the event of the trailer becoming detached, the tractor hydraulic line L separates at the breakaway coupling 20 and pulls the cable 21, thereby turning the lever valve 22 handle 36. The oil can now flow from the hydraulic accumulator 15 though the lever valve 22 to the hydraulic brake actuators 11, thus applying the trailer brakes.

The pressure gauge 30 allows the operator to check the successful operation of the breakaway system as the pressure gauge 30 will also display the oil pressure which would be applied when the emergency brakes are applied.

Unlike many other breakaway systems, reconnection is simple as the breakaway coupling 20 is designed to allow reconnection under pressure in a push-fit operation.

In summary regarding the testing, there is essentially a supply test, which is the value displayed by the gauge 30 as the location of the gauge 30 between the accumulator 15 and the closed valve 22 indicates the extent to which the accumulator 15 is charged and hence the available pressure for emergency braking. This may for example be 130 bar.

A second level of testing is achieved by uncoupling the line L at the coupler 20 and manually turning the handle 36. This causes the valve 22 to open, allowing flow of pressurised oil from the accumulator 15 to the actuators 11. The pressure gauge 30 level should be at or above a threshold which allows for the fact that the oil is now extending the pistons of the brake actuators 11. If the level is above the threshold, the user knows that there is sufficient oil available for emergency braking without adjustment of the brakes 11 or repairs. -7It will be appreciated that the breakaway braking interface 10 between the trailer and the towing vehicle also provides a system for connection of services between the tractor and the trailer i.e. hydraulics, pneumatics and electrics. Of course in some cases these interfaces may not all be used, and in some embodiments one or both of the electrical and pneumatic interfaces are not present. The interface arrangement is modular, with readily accessible components such as a lever valve, a breakaway connection, a pressure gauge, a check valve, and an hydraulic accumulator.

It will be appreciated that the interface is very versatile and comprehensive as it allows the trailer user to check that the tractor supply oil pressure is correct. It also allows the operator to verify that the accumulator is charged to the correct pressure before using the trailer. Finally, it also allows the operator to check the oil pressure achieved when the emergency brake is activated. This is very significant for equipment manufacturers also as it helps them to ensure that the accumulator sizing is compatible with the size of brake rams used.

Because the operator can verify breakaway oil pressure periodically, a low pressure reading will highlight poorly adjusted brakes or other problems.

The invention is not limited to the embodiments described but may be varied in constmction and detail. For example, the trailer may be any hauled device such as a slurry spreader or any agricultural or industrial hauled plant. Also, the system may include an auxiliary high pressure coupler for receiving hydraulic supply from the vehicle initially and possibly also on a periodic basis, for charging of the accumulator 15 with a higher-pressure supply than is available from the normal braking supply. Referring to Figs, 5 and 6 an interface 100 has a coupler 20, a pressure gauge 30 and interface components 40 and 45 as for the interface 1. A breakaway valve 101 has a lever 102 on the right hand side and this has a clip 103 with an eyelet linked to the cable 21. There is an auxiliary coupler 110 of a different configuration than the coupler 20, and suitable to take a feed from a tractor supply for implements such as a loader or top link. Such a supply has a higher pressure typically, such as say 180 bar, and so it can be used to ensure that the accumulator is adequately charged and the gauge 30 indicated sufficient accumulator pressure, with the needle in the “green” region. This is suitable especially for use with tractors which have a braking hydraulic supply which is adequate for braking but maybe not quite enough to adequately charge the accumulator with a safety margin. Fig. 6 shows the interface 110 with the vehicle-side coupler component pulled away and the lever 102 pulled.

Claims

1. A trailer interface to a towing vehicle, the interface comprising: a breakaway valve with a link for connection to a towing vehicle, and being arranged to open during a breakaway caused by pulling of the link to allow flow of oil from an accumulator to trailer brake actuators, and a pressure gauge adapted to indicate oil pressure available from an accumulator to trailer brakes in the event of a breakaway.

2. A trailer interface as claimed in claim 1, wherein the breakaway valve is a lever valve and said valve link is a cable or chain for connection to a vehicle so that the lever is turned upon a breakaway occurring.

3. A trailer interface as claimed in claim 2, wherein the interface includes a breakaway coupler for connection to a towing vehicle hydraulic line, and said valve link is arranged to be connected to a towing vehicle hydraulic line or coupler component, whereby upon a breakaway occurring the vehicle hydraulic line disconnects at the breakaway coupler and the link is pulled to open the breakaway valve.

4. A trailer interface as claimed in any preceding claim, wherein the pressure gauge is adapted to be connected to an hydraulic line between the breakaway valve and an accumulator.

5. A trailer interface as claimed in any preceding claim, wherein the pressure gauge is arranged to show accumulator pressure available if the breakaway valve is manually opened for testing.

6. A trailer interface as claimed in any preceding claim, wherein the interface includes pneumatic and/or electrical couplers.

7. A trailer interface as claimed in any preceding claim, wherein the interface comprises a support arranged to mount on the front of a trailer. -98. A trailer interface as claimed in any preceding claim, wherein the interface is arranged to allow a user to open the breakaway valve to test pressure in a braking system between the accumulator and the brake actuators. 5 9. A trailer interface as claimed in any of claims 3 to 8, wherein the coupler is of a push-fit type to allow re-connection by a user after a breakaway, thereby allowing brakes to be released.

8. 10. A trailer interface as claimed in any of claims 3 to 9, further comprising an auxiliary 10 hydraulic coupler which is different from said breakaway coupler and is adapted to receive oil from an auxiliary supply and to direct said supply to an accumulator.

9. 11. A trailer interface as claimed in claim 10, wherein said auxiliary coupler is adapted to receive a supply from a tractor implement hydraulic circuit.

10. 12. A braking system for a trailer, the braking system comprising an interface as claimed in any of claims 3 to 11, brakes and associated hydraulic actuators, and an accumulator, in which the pressure gauge is connected to an hydraulic line between the accumulator and the breakaway valve, and the breakaway valve is connected to allow supply of oil from 20 the accumulator to the brake actuators.

11. 13. A braking system as claimed in claim 12, further comprising a one-way valve linking the coupler with the accumulator, to allow flow of oil from a vehicle hydraulic line to the accumulator but to prevent, together with the breakaway valve, escape of oil from the 25 accumulator except when the breakaway valve is open.

12. 14. A trailer comprising a frame, wheels, and a draw bar, and a braking system as claimed in either of claims 12 or 13. 30 15. A method of testing a braking system of a trailer of claim 14, the method comprising manually disconnecting a vehicle hydraulic line from the interface, manually opening the breakaway valve, and the gauge indicating oil pressure between the accumulator and the brake actuators.