WO2001094151A1

WO2001094151A1 - Safety device for stabilising tipping vehicles

Info

Publication number: WO2001094151A1
Application number: PCT/AU2001/000662
Authority: WO
Inventors: Hayden Wesley Pullen
Original assignee: Hayden Wesley Pullen
Priority date: 2000-06-05
Filing date: 2001-06-04
Publication date: 2001-12-13
Also published as: AUPQ797600A0

Abstract

A safety device for vehicles (10) which tip loads which includes at least one tilt sensor (15) on the vehicle (10) and an arrangement whereby if the tilt sensor (15) indicates that the vehicle (10) is approaching a state of instability then any further tipping operation ceases and the body (11) of the vehicle (10) moves towards a position of greater stability to the vehicle (10) or is moved to its initial position restoring stability.

Description

Safety Device for Vehicles

This invention relates to a safety device for vehicles and in particular to a safety device for vehicles which make use of lifts for the purpose of emptying the contents of the vehicle, and specifically to vehicles which have a "tipping" body.

For ease of description we shall refer to a tip truck which normally has a chassis on the rear of which there is mounted a container or body (which we shall call for convenience the body) which is adapted to receive material which is later to be disgorged therefrom by rotating the body about an axis transverse to the vehicle near the rear thereof the rotation often being effected by a hydraulic or pneumatic ram or rams.

The invention can also be used for side delivery vehicles where the body is rotated about a longitudinal axis adjacent one side of the vehicle. In such vehicles there are normally means where the body can be rotated on either side of the vehicle and such arrangements are used with railway trucks or the like.

In all cases where a load is being tipped from the body, the centre of gravity of the vehicle changes, firstly as the body is rotated about its pivot and, secondly where part of the load has been delivered and the centre of gravity tends to move to the rear or side of the vehicle.

It is an object of the invention that when it is likely that a load in a vehicle has moved sufficiently to cause instability of the vehicle, stability is automatically recovered.

The invention includes a vehicle having a body which is adapted to contain material and which can be rotated to permit the delivery of the material therefrom, at least one sensor which can indicate that the vehicle is reaching a position of instability and means, the operation of which is initiated by such indication from the sensor, to cause the body to move towards a position of greater stability. In a specific form of the invention, the vehicle is a tip truck in which the body of the truck is caused to rotate about a generally horizontal; transverse axis by the use of an hydraulic or pneumatic ram and wherein there is at least one tilt sensor associated with the back axle of the truck, means calibrated to be actuated at a predetermined reading from the tilt sensor whereby the operation of the ram is stopped and it permitted to or caused to reverse to permit the body to assume a position of greater stability.

In order that the invention can be more readily understood, we shall describe embodiments of this in relation to the accompanying drawings, in which:

Figure 1 shows a schematic view of a vehicle with which the invention could be used;

Figure 2 shows a schematic view of the arrangement of the invention; and

Figure 3 shows a schematic view of the valve in the air diverter box which effects the change over.

Figure 1 shows a tip truck 10 of the type in which the body 11 and some, at least, of the rear wheels 12 are caused to rotate by a ram 20 which acts in association with a pivoted sub-frame 21 acting part- way along the length of the body.

The body 11 is normally provided with a door 13 or the like which closes the rear of the body and, as illustrated, this is pivoted at the top of the body about a transverse axis 14 and has lock means, not illustrated, adjacent its lower end the arrangement being such that when the contents of the vehicle are to be delivered the lock means are released and the body is caused to rotate about its pivot by means of the ram 20 which is normally a hydraulic ram, and will be referred to as such, but could be a pneumatic ram.

In the simplest case there can be a single ram but there could be more than one ram if required. As the ram 20 is operated, the lock means on the door are released and the door at the rear is free to move outwardly from the body, which it will do because of gravity and the change of angle of the body 11 and also because the material in the body will tend to strike the rear of the door and cause it to move outwardly as the material is being delivered.

In the system of the invention, there is at least one tilt sensor which is mounted on the rear axle 15 of the vehicle 10 and which ascertains the turning force between the wheels 16 as indicated by the axle casing or the body.

As the material being delivered from the body is delivered, there is a rearward movement of the centre of gravity of the whole vehicle and there can be a sideways movement of the centre of gravity of the material is delivered unequally and particularly if the vehicle is on a slope. There can be occasions, such as if the delivery of the material ceases but the body is continued to be raised that the centre of gravity will move sufficiently to cause the vehicle as a whole to become unstable and there is a turning moment about the rear wheels which, if uncontrolled, can cause the vehicle to tip sideways.

In the system of the invention when the sensors record the fact that there is likely to be such movement they cause operation of an override which commences to reverse the operation of the ram either positively or passively so that the body tends to be "lowered", in the case of a tip truck, and the vehicle moves to a position of stability.

If, say, the delivery of the material was prevented by a blockage this can be manually freed and the operation re commenced.

It will be seen then that whenever the vehicle reaches a situation where it is likely to become unstable this is corrected stability is reestablished and then the cause for the instability can be ascertained.

Referring to Figure 2, which is a schematic view of the operating components there can be in the vehicle's cabin, or elsewhere, a Power Take Off Controller 30 which can have two positions selectable by the operator, 'UP' and 'Down'. Operation of the UP control causes air to pass from the controller 30, by way of line 31 to a diverter box 40, to be described later, and a further line 32 to a valve 35, which is preferably a spool valve, to control an hydraulic valve 36 which, in turn, operates the ram 20. This operation is effected by high pressure fluid passing from a supply through line 39, the valve 36 to line 37 to the ram 20.

When the Down control is actuated, air passes through line 33, through the diverter box 40, through line 34 to the other side of the valve 35 which moves the valve 36 so oil flows down line 37 to an oil return line 38 from which it passes to a reservoir ready to be again pressurised when required.

The operation of the air diverter box is illustrated in Figure 3.

Under normal circumstances, the air passes as required through lines 31 and 32 and 33 and 34 as described above. Under these circumstances valves 42 and 43 are open and there is no restriction to flow.

When the tilt sensor 15 provides a signal which indicates near instability, and there may be a comparator circuit or other electronic ways of ascertaining this, there is a signal along line 50 which closes valves 42 and 43 so initially there is no further air passing along line 32. At the same time valve 45 opens so that any air in line 32 is vented to exhaust.

Also, valve 44 opens which permits a by-pass from line 32 to line 34. That is, the lowering operation of the ram 20 is initiated and the body starts to drop. That is, it moves to a position of greater stability.

The situation can be checked and, if necessary, the vehicle can be moved to a more satisfactory position or any obstruction can be removed. There can be a positive resent on line 50 or when the tilt sensor shows no problems, the valves 42, 43, 44 and 45 can be returned to their initial condition. Whilst we have stated that the sensor(s) are associated with the rear wheels of the vehicle it will be understood that they could equally well be associated with the front wheels or the body, depending on the most desirable position for any particular vehicle.

Also, the degree of sensitivity of the tilt sensor can be selected to provide the best protection for any particular application.

Whilst be described the lowering of the body as being passive, that is the weight of the body being sufficient to cause the body to fall, in some applications there can be positive movement of the ram of the hydraulic or pneumatic cylinder to lower the tray when it is emptied and if this system is used then a positive force would be applied to the correct side of the piston after the source of fluid or air raising the body is removed.

If the invention is applied to a side delivery vehicle, and in particular to one which can deliver from either side, then there will be sensors on each side of the vehicle and the initiation of the return movement can either be effected from the sensors on one side showing that there is about to be rotation or those on the other side showing that the weight on the wheels is reducing to a level which is unsafe.

In each embodiment of the invention once the operation had been effected there can be a reset arrangement which prevents further attempts to deliver the material without a positive operation, that is to prevent users simply recommencing the operation without ascertaining that this is safe.

Claims

I claim:

1. A vehicle having a body which is adapted to contain material and which can be rotated to permit the delivery of the material therefrom, at least one sensor which can indicate that the vehicle is reaching a position of instability and means, the operation of which is initiated by such indication from the sensor, to cause the body to move towards a position of greater stability.

2. A vehicle as claimed in claim 1 wherein the vehicle is a tip truck in which the body of the truck is caused to rotate about a generally horizontal; transverse axis by the use of an hydraulic or pneumatic ram and wherein there is at least one tilt sensor associated with the back axle, means calibrated to be actuated at a predetermined reading from the tilt sensor whereby the operation of the ram is stopped and it permitted to or caused to reverse to permit the body to assume a position of greater stability.

3. A vehicle as claimed in claim 2 wherein the movement of the body is by way of an hydraulic ram and the operation of the ram is controlled by a pneumatically actuated valve there being a diverter box through which air lines to control the air flow to the pneumatic valve which causes upward and downward movement of the ram, the diverter box having a valve means which can reverse the connection of the air when the tilt sensor has an output which is sufficient to indicate a situation of impending instability.

4. A vehicle as claimed in claim 3 wherein when the body is to be raised, a power take off control is manually operated to cause air to move the pneumatically actuated valve to connect the hydraulic ram associated with the body to be placed into connection with high pressure fluid and thus cause the body to rotate about is pivotal axis until the body reaches its position of maximum rotation for delivery of the contents thereof after which the power take off control can be moved to a position where the pneumatic valve causes the hydraulic valve to assume a condition at which the fluid can return to a reservoir and the body is permitted to move under its own weight to it initial condition, the signal from the tilt sensor causing the change in position of the pneumatic valve without action by the operator.