GB2286688A

GB2286688A - Hydraulic axle loading indicator

Info

Publication number: GB2286688A
Application number: GB9402912A
Authority: GB
Inventors: Peter Hanson
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-02-16
Filing date: 1994-02-16
Publication date: 1995-08-23
Also published as: GB9402912D0

Abstract

This design is to prevent commercial vehicles from overloading and measures the weight on each individual axle. Two hydraulic jacks 2 are mounted on the chassis above each axle and are charged from a pump driven by a PTO to push down on the axles, raising the vehicle body back to its position prior to loading. The pressure required to operate each pair of jacks is measured to determine the axle loading or alternatively the jacks can act through hydraulic load cells 8, the loading being displayed on one or more gauges 22 in the vehicle cab. When the load has been checked the jacks are retracted back and the vehicle is free to travel. A gauge or warning light shows when the jacks are operative.

Description

PATENT SPECIFICATION COMMMERCIAL VEHICLE HYDRAULIC CHECKWEIGH This invention relates to road vehicles and to means for assisting in obtaining balanced weight distribution and axle loadings.

It is well known that road vehicles are often overloaded overall, or individual axles are overloaded but this is often inadvertent. It is quite a problem loading a vehicle with even weight distribution and loading on the axles according to the load for which each axle is designed. Correct loading is of more major importance now certain rules and regulations are law.

The main object of the present invention is to try and solve the above problem.

Accordingly there is provided a method of indicating weight distribution and axle loadings on a road vehicle, including hydraulically charging or operating a pair of jacking devices in relation to each or selected axles of a vehicle, and causing hydraulic pressure created by the jacking devices to show an indication on gauge means.

The improved method of indicating weight distribution and axle loadings on a road vehicle includes applying a lifting force to at least one region of the load bearing part of the vehicle and causing said force to create a fluid pressure to operate an indication system or means capable of registering the weight of the load on an axle.

The method may include supplying hydraulic pressure to the jacking devices from pump means operated by a power-take-off from a vehicle part, such as a gear box, through manually operated valve control means or by electric P.T.O.

The invention includes providing a pair of hydraulic jacking devices mounted to apply a force to each required axle for checking purposes, a hydraulic pressure system of co-related or independent connections between the devices and a hydraulic pump means for pressurising the fluid, and a second hydraulic system of co-related or independent connections associated with each pair of devices and connected to indication gauge means for indicating load deflection when the jacking devices are operative. A separate gauge may be provided for each pair of jacking devices.

Moreover, the invention includes providing a pair of hydraulic jacking devices mounted to apply a force to each required axle, fluid containing pads to be acted upon by said jacks, said pads being incorporated in a load indicating system so that when the fluid is pressurised in the pads by the operation of the jacks a load indication will be given on at least one indicator. Said indication system may be wholly hydraulic or the fluid adapted to operate an electrical system.

This improved system with fluid containing pads fitted to a vehicle axle beam or road spring records separate axle loadings, but if the pads are fitted between the body and chassis, i.e. the body rests on the pads, then the system simply weighs the load in the body.

The invention will now be more particularly described with reference to the accompanying drawings, in which Fig. 1 is a diagrammatic layout of the hydraulic systems and apparatus on a vehicle; Fig. 2 is a perspective view of one jack; Fig. 2A Jack incorporating valve to checkweigh with jack pressure; Fig. 3 is a perspective view of one hydraulic pad on an axle; and Fig. 4 is a perspective view of one hydraulic pad alternatively on a road spring; Fig. 4A Tipper and freight application.

In a particular embodiment of this invention a commercial road vehicle 1 is provided with a pair of jacking devices 2 for each axle 3 and 4 adjacent the road springs 5, tsLe cylinders of the devices being securely mounted on the vehicle chassis 6 with their rams 7 extending downwardly to bear on to hollow piston containing pads 8 attached to the case of axle 3 or 4, or the bracket 9 of the road springs 5. The two devices 2 of each pair are connected by linking pipes 10 and 11 of a hydraulic system having pressure pipes 12 and return feed pipes 13 connected to such linking pipes and also to a pressurising pump unit.

The latter can form part of or be operated by a power-take-off unit 14 connected to the vehicle gear box and arranged to draw oil from a reservoir 15. The usual manual valve control means 16 are provided for controlling the unit 14. Further valve means 17 are provided for admitting and releasing pressure to and from the system 12 for the jacking devices 2 and such valve means can be operated by manual control means 18 which can be located conveniently in the cab of the vehicle.

When desired the valve control means 17 can be employed for the jacks 2 to operate to in effect lift the vehicle in relation to its axles 3 and 4 with consequent spring deflection. h gauge 19 andj or a warning light Sü is provided to show when the jacks 2 are operative, e.g. fully extended. h second pre-sealed hydraulic static oil system 21 is connected to the hollow pads and this second system is connected to a pressure gauge 22 (or a set of pressure gauges) which can be marked off in, say, tons and hundredweights. When the jacks are operated they act on the pistons of the pads 8 to pressurise the static oil in the system 21. The gauge (or gauges) can be arranged in the vehicle cab for easy observation, or reading taken from jack pressure as in 2A.

Although only one gauge 22 is shown there can be a gauge for each pair of pads or a gauge for each pad.

Alternatively, fluid, pressurised in each or a pair of pads or all the pads, may be arranged to operate switch means in an electrical circuit incorporating indication means.

The invention can be applied to a vehicle having two or more axles or means to which the pads can be attached. An advantage is the recording system which is sealed so that pressures never vary due to the fluid being static until the pads are pressurised, Fig. 2A method being more suited to tipping vehicles.

In use, with the vehicle stationary, and under loading, the various jacking devices are charged with oil for the spring deflection to be measured by the jacks operating the pad containing system which causes the loading to be shown on a gauge or the various gauges in the cab.

Any required adjustment in the load of the vehicle can then take place and when the vehicle is satisfactorily loaded the release valve 23 can be operated to allow the rams of the jacks to be retracted by hydraulic or spring pressure and leave the suspension of the vehicle free to operate in the normal manner. For such release, each jack includes a take-off pipe 24 with which an annular by-pass port in the periphery of the ram 7 can register. Pipe 24 may be connected into the hydraulic jack system or directly through the release valve 23 to the tank 15.

Alternatively, the aforesaid pads may be located between a chassis and body to be engaged by jacks or other means for load weighing purposes.

If desired the body may normally be supported clear of the pads and lowered thereonto for weighing purposes. Screw jacks instead of hydraulic jacks may be used.

Instead of using pad 8 this same overall system is used but the weight reading is taken from the jack pressure in upper cylinder by using an automatic two way valve in the jack piston. This method is more suited to tipper vehicles in rough terrain.

WHAT I CLAIM IS: 1. A method of indicating weight distribution and axle loadings on a road vehicle, including hydraulically charging or operating a pair of jacking devices in relation to each or selected axles of a vehicle, and causing hydraulic pressure created by jacking devices to show an indication on gauge means.

2. A method of indicating weight distribution and axle loadings on a road vehicle comprising applying a lifting force to at least one region of the load bearing part of the vehicle and causing said force to create a fluid pressure to operate an indication system or means capable of registering the weight of the load on an axle.

3. Method according to claim 1 or 2, including providing a pair of hydraulic jacking devices mounted to apply a force to each required axle for testing purposes1 a hydraulic pressure system of co-related or independent connections between the devices and a hydraulic pump means for pressurising the fluid, and a second hydraulic system of co-related or independent connections associated with each pair of devices and connected to indication gauge means for indicating load deflection when the jacking devices are operative.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. If desired the body may normally be supported clear of the pads and lowered thereonto for weighing purposes. Screw jacks instead of hydraulic jacks may be used. Instead of using pad 8 this same overall system is used but the weight reading is taken from the jack pressure in upper cylinder by using an automatic two way valve in the jack piston. This method is more suited to tipper vehicles in rough terrain. WHAT I CLAIM IS:

1. A method of indicating weight distribution and axle loadings on a road vehicle, including hydraulically charging or operating a pair of jacking devices in relation to each or selected axles of a vehicle, and causing hydraulic pressure created by jacking devices to show an indication on gauge means.

4. Method according to claim 3, including supplying hydraulic

pressure to the jacking devices from pump means operated by a powertake-off from a vehicle part, such as a gear box, through manually operated valve control means.

5. Method according to claim 1 or 2, including providing a pair of hydraulic jacking devices mounted to apply a force to each required axle, fluid containing pads to be acted upon by said jacks, said pads being incorporated in a load indicating system so that when the fluid is pressurised in the pads by the operation of the jacks a load indication will be given on at least one indicator, or as in Fig.

2A the pressure reading is taken from the hydraulic jack.

6. Method according to claim 2, wherein the indication system is wholly hydraulic.

7. Method according to claim 2, wherein the indication system is partly hydraulic for fluid under pressure to operate an electrical system.

8. Method according to claim 1 or 2, including mounting fluid containing pads between a vehicle body and chassis causing the body to rest on the pads and create fluid pressure.

9. Apparatus for indicating weight distribution and axle loadings on a road vehicle, comprising a controllable hydraulic system incorporating hydraulic jacks adapted to be mounted relative to the vehicle axles, and a further system capable of recording the vehicle loading when the jacks are operative.

10. Apparatus according to claim 9, wherein the second system is a pre-sealed hydraulic system incorporating means to be acted upon by the jacks to create fluid pressure, and load indication gauge means in this second system.

11. Apparatus according to claims 9 and 10, wherein each required vehicle axle has a pair of hydraulically connected jacks in a manually controlled system incorporating indication means.

12. Apparatus according to claim 10, wherein the second hydraulic system incorporates piston containing hollow pads for pressurising the oil in the system, said pads being associated with an axle or spring assembly in alignment with the jacks which are fixed to the vehicle structure.

13. Apparatus according to any of the preceding claims 9 to 12, wherein the hydraulic system incorporating the jacks is pressurised by a pump and power-take-off unit driven by the vehicle, and an oil reservoir for the system.

14. Method of indicating weight distribution and axle loadings on a vehicle substantially as described.

15. Apparatus for indicating weight distribution and axle loadings on a vehicle substantially as described with reference to the accompanying drawings.

16. For tipper application on rough terrain the pressure reading is taken from the hydraulic jack when automatic valve closes at full extension against a solid steel pad fitted to axle beam.