GB2220758A

GB2220758A - Vehicle on-board weighing means

Info

Publication number: GB2220758A
Application number: GB8914655A
Authority: GB
Inventors: John Wood
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-06-24
Filing date: 1989-06-26
Publication date: 1990-01-17
Also published as: GB8815108D0; GB8914655D0

Abstract

In an onboard vehicle weighing system comprising one or a number of strategically located load sensitive means e.g. transducer 1 mounted on chassis 6, in association with a load bearing area or container, each load sensitive means has mounted thereon a bearing block 8 provided with a cylindrically bored rotatable ball 10 through which load may be applied from the load bearing area or container to the load sensitive means in the optimum direction (normal to transducer 1) irrespective of the disposition of the load bearing area or container. Each transducer 1 is secured to a mounting plate 3 with an interposed resilient layer 4 and the plate is welded to a locating plate 5 secured to chassis 6. An axle of a platform or container on the chassis can extend through bores 11 in rotatable balls 10 of load sensitive means mounted at either side of the chassis. At the front end of a tipper vehicle a load sensitive device may be mounted on the chassis and an axle on which the operating ram is located extends through the bearing block 8. Weighing in the tipper vehicle only commences when the container is raised from its normal position hard down on the chassis. A processor receives signals from the transducers during tipping enabling weighed partial loads to be delivered. <IMAGE>

Description

VEHICLE LOAD WEIGHING MEANS This invention relates to weighing means for vehicle loads.

There is the extensive use of road transport for the bulk delivery of a variety of types of particulate and fluid materials and where delivery is made on the basis of the weight of material required. There is therefore the known use of weigh bridges where the vehicle is weighed with and without its load to confirm the weight of the load delivered.

Given the fact that the provision of weigh bridges is far from commonplace, it is frequently impossible to use this technique as a means of checking the weight of a delivered load, and when the recipient has no option but to assume that the vehicle had been correctly loaded.

This problem is heightened when a particular load on one vehicle is intended for delivery to two or more recipients, each taking a proportion of the total load.

Here even when it can safely be assumed that the vehicle had properly been loaded with the total load, the frequent absence of a conveniently located weigh bridge makes it impcssible to guarantee that each recipient receives its required proportion of the total load.

This has led to the development of on-board weighing systems where load-sensitive transducers are strategically positioned below the load bearing area of a vehicle or associated with a container mounted on the vehicle.

However, the accuracy of reading taken from a load-sensitive transducer is seriously impaired if the direction of application of a load to it is incorrect. Given the inherent flexibility of a load bearing area of a vehicle, and its permitted movement by virtue of its resilient mounting on the vehicle axles, present on-board weighing systems can only provide an approximate indication of a vehicle load that does not have the accuracy required by such organisations as the Department of Trade and Industry, and the Office of Fair Trading. The problem of providing a sufficient accuracy by an on-board weighing system is heightened in vehicles generally referred to as tipper vehicles, where the load bearing area or a container is raised at one end to dispense the load from the other end.With the load bearing area or container in its inclined condition to permit the dispensing of the load, present on-board weighing systems are unable to provide any reliable reading that can be used by the operator to gauge when a required proportion of a total load has been discharged.

It is the object of the present invention to provide an on-board weighing system for vehicles that overcomes the disadvantages mentioned above.

According to the present invention an onboard weighing system for a vehicle comprises one or a number of strategically located load sensitive means in association with a load bearing area or a container on the vehicle, there being a means interposed between the or each load sensitive means and the load bearing area or container and connected directly or indirectly to the load bearing area or container with freedom for relative rotation, and whereby irrespective of the disposition of the load bearing area or container the vehicle load is applied through the interposed means to the load sensitive means in the direction required to permit a reading of maximum accuracy to be provided by the load sensitive means.

Thus, the load sensitive means may be load sensitive transducers, and preferably the load sensitive transducers are provided on mounting plates to facilitate them being secured to a fixed member of the vehicle, such as a chassis member. It is further preferred to interpose a layer of a resilient mounting material between the mounting plates and the, e.g., chassis member to provide a limited degree of flexibility at the mounting points of the trandsucers.

Preferably, the interposed means is a bearing block suitably located in fixed space relationship to the respective transducer and such as to be able to apply load to the transducer, the bearing block having a generally cylindrical cavity containing a rotatable, apertured, ball member. In its application to a so-called fixed platform lorry, the interposed means may also include brackets to be secured directly to the load bearing area with stub axles on the brackets to engage an aperture of a respective ball member. Thus, articulation of the load bearing platform is accommodated by the ball means, and when the load applied through the bearing block to the transducers is in a substantially normal direction to the plane occupied by the transducer.

In the application of the invention to so called tipper lorries, the load bearing transducers are associated with the axle at the (rear) end of the vehicle about which the load bearing area or container is pivoted and with the or each axle of the or each pivotally mounted hydraulic ram provided at the other (forward) end of the vehicle. Here again, the transducers are preferably on mounting plates secured to a chassis member with an interposed layer of resilient mounting material, but in this instance, a separate bracket and stub axle is not required, it being the ram axle or axles and the load bearing area or container axle that engage in the apertures of the balls in the bearing blocks secured in fixed space relationship with respect to mounting plate.Thus, a transducer mounting plate and bearing block is provided to each side of the rear end of the vehicle to be engaged by opposite ends of the load bearing area or container axle. At the front end of the vehicle, and when a single centrally positioned operating ram is employed two transducer mounting plates and bearing blocks are provided, one te each side of the ram and for engagement by the ram axle at both sides. Alternatively when two rams are provided a single transducer mounting plate and bearing block is provided each for engagement by one end of the respective ram axle.

In all instances, it is advantageous to provide a relatively simple processor means to accept readings from all the transducers, which can then be summated to provide an output signal that is an accurate representation of the vehicle load, and visual read-out means can be provided where convenient.

In its application to tipper lorries, the invention has the advantage that during transport, the load bearing area or container can be hard down on the vehicle chassis, and at the point where the load is to be dispensed, the area or container first lifted by a small amount and when the weighing system becomes active to give a first read out of total load. As the area or container is lifted by the ram, the articulation of it is accommodated by the connection of the axles to the bearing blocks, ensuring that the load is correctly applied to the transducers, and when continuous accurate monitoring of the load is possible, and whereby dispensing of the load can be halted when a required proportion of the load has been discharged.

One embodiment will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a side elevation of one embodiment of load sensitive means according to the invention; Figure 2 is an end elevation of Figure 1; Figure 3 is a section on the line 3 - 3 of Figure 4; Figure 4 is a side elevation of a second embodiment of load sensitive means according to the invention; and Figure 5 is a side elevation of Figure 3.

The embodiments illustrated in the drawings are for use with tipper lorries, where a load bearing platform or a container is mounted on the chassis by an axle at the rearward end and about which the platform or container can be pivoted by ram means towards the forward end pivotally secured to the platform or container, and by an axle chassis.

Thus, as is illustrated in Figures 1 and 2 a load sensitive means according to the invention is formed by a load sensitive transducer 1 secured by bolts 2 to a monitoring plate 3 with an interposed layer 4 of resilient material provided. The mounting plate 3 is secured by welding to a locating plate 5 and whereby the assembly can be secured to a chassis member 6 by bolts 7. Located on the load sensitive transducer 1 is a bearing block 8, and which as is shown particularly by Figure 3, has a cylindrical walled passageway 9 located in which is a rotatable ball 18 having a cylindrical bore 11. A bearing cover 12 is provided to be between the bearing block 8 and the locating plate 5.

With then two such load sensitive means provided each secured to a chassis member to opposite sides of the vehicle and towards the rearward end, an axle 13 on which the rearward end of a platform or container can project through the assembly and particularly the bore 11 of the rotatable bore. As is illustrated in Figures 4 and 5, a load sensitive means in accordance with the invention again has a load sensitive transducer 1 secured to a mounting plate 3 with an interposed layer of resilient material 4. Again a bearing block is located on the load sensitive transducer, the bearing block being constructed in like manner to that illustrated in Figure 3. With this embodiment, the assembly is located on a chassis member 14 disposed towards the front of the vehicle, and an axle 15 on which the operating ram is mounted extends through the bearing block.

In a circumstance where a single ram is employed, two such load sensitive means are provided, one to either side of the ram, and when it is two rams that are employed, one such means is provided in close relationship to a respective ram.

The load bearing transducers are preferably connected to an appropriate processor means and whereby the indication of load given by all of the transducers can be summated into a single reading of load with the effect that has on the enhancement of the accuracy on the indication of load provided. Thus, the processor means can be provided in for example the vehicle cab and have an attendant visual display for viewing by the operative.

In its application to tipper lorries, the invention has the advantage that during transport the load bearing area or container can be hard down on the vehicle chassis until the point is reached where the load or more particularly a part of the load is to be dispensed. As the load bearing area or container is first lifted by a small amount, the weight of the load on the platform or in the container is transferred to the pressure transducers.

As a consequence of having the or each axle of the or each ram and the axle about which the platform or container hinges located in respective rotatable balls in the bearing blocks, any articulation (within practical limits) of the axles is accommodated by the rotatable balls with the effect that the load applied to each load sensitive transducer through the bearing block is maintained substantially normal to the plane of the transducer with the beneficial effect that that has in ensuring high accuracy of the indication of weight provided by each transducer.

Claims

1. An onboard weighing system for a vehicle comprising one or a number of strategically located load sensitive means in association with a load bearing area or a container on the vehicle, there being a means interposed between the or each load sensitive means and the load bearing area or container and connected directly or indirectly to the load bearing area or container with freedom for relative rotation, and whereby irrespective of the disposition of the load bearing area or container the vehicle load is applied through the interposed means to the load sensitive means in the direction required to permit a reading of maximum accuracy to be provided by the load sensitive means.

2. An onboard weighing system as in Claim 1, wherein the or each load sensitive means is a load sensitive transducer.

3. An onboard weighing system as in Claim 1 or Claim 2, wherein a layer of resilient mounting material is interposed between the load sensitive means and the mounting plate.

4. An onboard weighing system as in any of Claims 1 to 3, wherein the interposed means is a bearing block suitably located in fixed spaced relationship to a respective transducer.

5. An onboard weighing system as in Claim 4, wherein the bearing block has a generally cylindrical cavity containing a rotatable apertured ball member.

6. An onboard weighing system as in any of Claims 1 to 5, wherein the interposed means also include brackets to be secured directly to the load bearing area with stub axles on the brackets to engage the interposed means.

7. An onboard weighing system as in any of Claims 1 to 5, wherein the load sensitive means are secured directly to the chassis members of the vehicle for engagement by axles associated with a tippable load bearing platform or container and ram means for tipping such load bearing platform or container.

8. An onboard weighing system as in Claim 7, wherein two load sensitive means are provided to either side and towards the rear of the vehicle for engagement by opposite ends of the axle about which the load bearing platform or container is pivotal.

9. An onboard weighing system as in Claim 7 or Claim 8, wherein two load sensitive means are provided towards the front of the vehicle to lie to either side of and be engaged by the axle of a single ram means.

ier. An onboard weighing system as in Claim 6 or Claim 7, wherein two load sensitive means are provided towards the front of the vehicle each to lie in close proximity to a respective one of two ram means, and with each load sensitive means to be engaged by the respective axle of one said ram.

11. An onboard weighing system substantially as hereinbefore described with reference to the accompanying drawings.