AU2004216644B1 - An Actuator for a Brake Isolator Lever - Google Patents

Description

o An Actuator for a Brake Isolator Lever ci 0Field of the Invention 0 This invention is directed to an actuator (for instance a solenoid actuator) which can be attached to a brake isolating lever which is typically found on large towed vehicles such as trailers, caravans, and the like, and IND which can function to automatically manipulate the lever.

oBackground Art ci Most countries have laws governing trailer braking requirements. In most countries, once the gross weight of the trailer is over a certain amount, the trailer must be provided with its own braking system.

Therefore, most caravans, large trailers etc. are provided with their own braking system.

Most countries also have laws that require the trailer braking system to have a safety feature which activates the brakes should the trailer move in a rearwardly direction. This safety feature prevents a car from being dragged backwards down an incline because of the weight of an attached caravan.

One common type of brake is a hydraulic brake and especially a hydraulic surge brake. This braking system provides automatic proportional braking of the towed vehicle caravan) with the leading vehicle (e.g.

car). The braking system works by creating a mechanical pressure caused by differential pressure developed between the trailer and the leading vehicle, and the mechanical pressure can be applied to the pushrod of the master cylinder. The mechanical pressure is proportional to the difference in pressure between the two vehicles and therefore the braking between the two vehicles is 2 o proportional and regulated. This is important to prevent Cl the towed vehicle caravan) from braking differently o from the leading vehicle.

A disadvantage with this system is that the system cannot distinguish between braking while towing and the mechanical pressure which is created when the trailer is backing up. Thus, the trailer cannot be reversed as the IN brakes of the trailer are applied.

l o To overcome this disadvantage, many caravans and other Cl types of towed vehicles are provided with a brake isolating lever which is positioned on the tow bar. The lever must be flicked to one side to deactivate the hydraulic brakes thereby enabling the towed vehicle to be reversed.

It is not very efficient to have this type of system as, to reverse the trailer, it is necessary to stop the leading vehicle, leave the vehicle, move over to the tow bar, flick the brake isolating lever to one side to deactivate the brakes, move back into the vehicle, and reverse the vehicle. Should the leading vehicle and the trailer be on an incline, there can be a "danger period" between the time that the brake isolating lever is flicked over to deactivate the brakes and before the driver can move back into the vehicle. Clearly, it is not advantageous to have any time where the trailer can have deactivated brakes and where the driver of the leading vehicle is not in the vehicle to possibly apply the vehicle brakes should there be a problem.

Another disadvantage with the system is that once the trailer has been reversed, it is necessary to again leave the vehicle, walk to the tow bar, flick the brake isolating lever back to the "activated" position and move back to the vehicle. If the driver forgets to do this, the trailer brakes remained disengaged, and this can be 3 o very dangerous during normal driving.

ci o Occasionally, it is necessary to reverse the trailer a few times in order to position the trailer in exactly the right place. This requires the trailer to move forwardly then be reversed, move forwardly again, be reversed again etc. Clearly, it is greatly inconvenient if it is necessary to leave the vehicle to activate and deactivate the brake isolating lever every time.

o Also, there may be times when the weather is cold, rainy, 0g windy, sleeting etc., and there is no desire for the driver to leave the vehicle to move the brake isolating lever.

To overcome at least some of the above-mentioned disadvantages, it is known to provide a rather complicated electrical system that deactivates the hydraulic brakes when the trailer is reversed. However, the system is expensive, and not all types of braking trailers are provided with this system, and it is very common for the trailer to have the simpler lever as described above.

Although it is common for the trailer to be provided with hydraulic brakes, other types of braking systems are also known including electrical brakes.

Therefore, there would be an advantage if it were possible to provide a relatively simple and robust system which could manipulate an existing brake isolating lever and which could overcome at least some of the abovementioned disadvantages.

It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in 4 o Australia or in any other country.

ci 0 Object of the Invention 0 It is an object of the invention to provide an actuator that can operate a brake isolator lever on a trailer and which may overcome at least some of the above-mentioned disadvantages or provide a useful or commercial choice.

IO

In one form, the invention resides in an actuator to o operate a brake isolator lever on a trailer, the actuator 0g comprising an operating member which is operatively connected to the brake isolator lever and to enable the brake isolator lever to be moved from the use position to the isolating position, and means to operate the operating member, the means being operable from a position remote from the brake isolator lever.

In another form, the invention resides in an actuator to operate a brake isolator lever on a trailer, the actuator comprising an operating member which is operatively connected to the brake isolator lever and to enable the brake isolator lever to be moved from the use position to the isolating position, and means to operate the operating member, the means being automatically operable upon reversing of the trailer and/or the leading vehicle and/or upon engagement of the reverse gear in the leading vehicle.

Suitably, the means to operate the operating member comprises a solenoid, and the operating member which is operatively connected to the brake isolator lever comprises part or all of the solenoid piston.

Thus, in a preferred, but non-limiting version of the invention, the actuator comprises a solenoid of the type having a solenoid housing and a solenoid piston, the piston being movable between an extended position and a o retracted position, the piston being connected to, or ci relative to the brake isolator lever such that operation U of the solenoid causes the brake isolator lever to move 0 between a use position and an isolating position.

In this form of the invention, the solenoid may be connected to the wiring of the reverse lights such that when the reverse lights are activated, the solenoid is D activated to move the brake isolator lever to the i 10 isolating position.

0 Suitably, when the vehicle no longer reverses, or is put into a forward gear, the solenoid returns the brake isolator lever back to the normal braking position (the use position).

Alternatively, the solenoid may be activated from inside the vehicle, and preferably inside the vehicle driver's area. In this embodiment, the solenoid may comprise a manual switch that can be activated by the driver of the vehicle to engage or to disengage the brake isolator lever.

Of course, it should be appreciated that there may be other means by which the solenoid can be activated.

The term "trailer" is not meant to be construed in a limiting fashion and is meant to include any type of vehicle that is towed behind a leading vehicle. Thus, the term "trailer" can include a caravan, a boat trailer, a box trailer, a horse float, a car carrying trailer and the like.

The actuator may be fitted to or relative to the tow bar or at or adjacent the brake isolator lever.

The brake isolator lever will typically be of a known type which comprises an elongate metal bar that functions 6 o as a lever.

ci 0 The operating member may comprise an elongate arm, and preferably comprises part or all of the solenoid piston.

The operating member may be connected directly to the isolator lever. Suitably, the operating member is connected to an upper part of the isolator lever.

VO

The solenoid, if used, may be of conventional manufacture and will typically comprise a solenoid housing and a o solenoid piston.

ci Brief Description of the Drawings An embodiment of the invention will be described with reference to the following drawings in which: Figure 1. Illustrates a side view of an actuator attached to a brake isolator lever.

Figure 2. Illustrates a top view of the actuator of figure 1.

Best Mode Referring to the illustrations, there is shown an actuator for a brake isolator lever attached to the tow bar of a caravan. The actuator in the particular embodiment comprises a solenoid which contains a solenoid housing 11 and a solenoid piston 12. Piston 12 is attached to the brake isolator lever 13 in a pivoting manner and in the particular embodiment, piston 12 is bifurcated and therefore comprises a pair of spaced apart arm members extending to each side of the brake isolator lever 13, this being best illustrated in figure 2.

Piston 12 is attached to an upper portion of lever 13.

The solenoid is mounted to an L-shaped bracket 14 such 7 o that it is held in a horizontal position adjacent the ci upper part of lever 13.

0 The solenoid is electrically powered and is ultimately powered from the vehicle battery.

In this particular embodiment, the solenoid can be wired to the reverse light switch of the vehicle such that when ND the light switch is activated the vehicle is put i 10 into reverse), the solenoid is activated to cause the o piston to move lever 13 to the isolating position where 0 the brakes on the caravan disengage. Conversely, when the rear lights are deactivated the vehicle is put back into neutral or a forward gear), the solenoid moves the lever to the brake activating position. In this manner, there is little or no possibility of the lever being in the wrong position.

In another embodiment, the solenoid can be electrically wired via a dash mounted switch such that the driver can manually activate or deactivate the brakes of the caravan. The dash mounted switch can contain a light or an audio warning signal if desired.

In this manner, the existing brake isolator lever can be moved from one position to the other position in an effective manner and without the disadvantages that exist with a manual movement of the lever, these disadvantages including the "danger period" where the lever is disengaged, but the person is not yet in the vehicle, the disadvantage in forgetting to return the lever back to its activating position, and the other disadvantages mentioned above.

Throughout the specification and the claims (if present), unless the context requires otherwise, the term "Icomprise", or variations such as "comprises" or "comprising", will be understood to apply the inclusion 8 O of the stated integer or group of integers but not the ci exclusion of any other integer or group of integers.

O

0 Throughout the specification and claims (if present), unless the context requires otherwise, the term "substantially" or "about" will be understood to not be limited to the value for the range qualified by the terms.

Va It should be appreciated that various other changes and o modifications can be made to any embodiment described 0 without departing from the spirit and scope of the invention.

Claims (6)

1. An actuator to operate a brake isolator lever Zon a trailer, the actuator comprising a solenoid which is 0O operatively connected to the brake isolator lever and, which upon operation, moves the brake isolator lever between the use position and the isolating position, the solenoid being wired to the power supply of a vehicle IND which tows the trailer and able to be actuated from a IND position remote from the brake isolator lever, the ci solenoid moving the brake isolating lever to the isolating position when the vehicle is reversing or is in C reverse gear.

2. The actuator of claim 1, wherein the solenoid is wired to the reverse light wiring of the vehicle to be activated upon current flowing through the reverse light wire.

3. The actuator of claim 1, wherein the vehicle is provided with a manual switch in the vehicle cabin which operates the solenoid.

4. An actuator to operate a brake isolator lever on a trailer, the actuator comprising an operating member which is operatively connected to the brake isolator lever and to enable the brake isolator lever to be moved from the use position to the isolating position, and means to operate the operating member, the means being operable from a position remote from the brake isolator lever.

A trailer having a brake isolator lever and an actuator as claimed in any one of the preceding claims.

6. An actuator substantially as hereinbefore described with reference to the illustrations. Dated this 1 8 th day of July 2005 Alan John Crees and Desleigh Robyn Crees By their Patent Attorneys CULLEN CO.