GB2352524A

GB2352524A - Trailer noseweight indicator

Info

Publication number: GB2352524A
Application number: GB9928003A
Authority: GB
Inventors: Michelle Louise Dagnall
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-07-23
Filing date: 1999-11-29
Publication date: 2001-01-31
Anticipated expiration: 2019-11-29
Also published as: ZA200003617B; GB9928003D0; GB9917209D0; GB2352524B

Abstract

The noseweight of a towed vehicle such as a trailer or caravan is measured when the nose of the vehicle is supported on a jockey wheel 12. The jockey wheel assembly includes a calibrated spring 4 and a scale 7 to indicate the movement of an inner telescopic tube 8 relative to an outer tube 6 against the bias of the spring. A peg 10 can be inserted in hloes 19 and 21, after partial compression of the spring 4, to hold the jockey wheel in an out of use, retracted, position.

Description

2352524 TRAILER NOSEWEIGHT INDICATOR This invention relates to a

noseweight measuring mechanis mi for towed vehicles such as caravans, camping trailers, boat trailers, car transporters and general purpose trailers.

In some countries notably France, it is illegal for a person not to know the noseweight of the caravan which they are towing. Caravan and trailer users all share the same problem of not being' able to measure their caravan or trailer's noseweight effectively and efficiently. The disadvantage of using the existing noseweight gauges that are on the market is that they take time to set up and need to be stored in the caravan if they are to be used whilst away from home.

The present invention provides a noseweight measuring device incorporated into the jockey wheel assembly of a towed vehicle so that noseweight measurements can be taken quickly, easily, accurately and without the need for unpacking, setting up, dismantling and storage of the device.

A preferred embodiment of the invention comprises the following parts.

A calibrated spring incorporated within the body of the jockey wheel assembly to measure the noseweight of the trailer. The spring is suited to a range of vehicles and noseweights and is incorporated inside the jockey wheel assembly without interfering with its normal:ftmction of supporting, moving and raising / lowering the trailer drawbar.

A clearly visible scale indicates the noseweight measurement derived from the spring.

A locking peg prevents unnecessary wear on the spring and enables the jockey wheel to be retained in a retracted position when the trailer is being towed.

A pair of telescopically interfitted tubes are used to house the spring and include a threaded nut for co-operation with a threaded stem of the kind conventionally used to raise and lower a jockey wheel.

2 A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:- Figure I shows a cross-section of the noseweight measuring device when taking a reading.

Figure 2 shows.the spring housed inside the body of the jockey wheel assembly.

Figure 3 shows a partial cross-section of the noseweight measuring device when in the locked position'.

Referring to Figure 1, the device consists of an outer tubular body 5 rigidly attached to a trailer drawbar 15. A threaded stem 2 is rotatable by means of a handle I and is supported in an axially fixed position in the body 5 by a thrust bearing 13. A first telescopic tube 8 carries a yoke I I at its lower end, for mounting a jockey wheel 12. The first telescopic tube 8 has a downwardly facing shoulder 17 towards its upper end, which co-operates with a collar 9 attached to the lower end of a second telescopic tube 6 so as to retain the tubes 6, 8 in telescopic sliding engagement. A nut 3 is attached to the upper end of the second telescopic tube 6 for co-operation with the threaded stem 2, to raise and lower the jockey wheel 12 as the handle I is turned. A compression spring 4 which is calibrated to measure noseweights of up to I 10 kilograms is interposed between the nut 3 and the upper end of the first telescopic tube 8. The lower end of the stem 2 extends freely through the core of the spring 4 and the hollow interiors of the first and second telescopic tubes 6, 8. A scale 7 is marked on the outside of the first telescopic tube 8 and co- operates with the lower surface of the collar 9 to indicate the noseweight supported by the jockey wheel 12. When the jockey wheel is to be taken out of use, the spring 4 may be at least partially compressed (e. g. by leaning on the handle 1 whilst the jockey wheel is still on the ground) so as to bring holes 19 in the collar 9 into alignment with a transverse hole 21 in the first telescopic tube 8. A locking peg 10 can then be inserted through the holes 19 and 21. The handle -1 can then be turned to raise tile jockey wheel into a retracted position.

3 Figure 2 shows the specification of the spring which is incorporated inside the body of the jockey wheel. As shown in the drawing the spring has an uncompressed length LI and a fully compressed length L2 achieved at a load of 110 kg (approx. I I OON). Its core 5 diameter is sufficient to allow the stem 2 to pass freely through it.

In order to operate the noseweight indicating device, the locking peg 10 is removed to enable the spring to move freely. In this position the spring produces a noseweight reading on the scale 7 against the collar 9. After a measurement has been taken the spring io is compressed'and the locking peg is replaced as illustrated in Figure 3.

The invention is not limited to the use of a spring for weight measurement. Other weight measuring means will be readily apparent, for example a force transducer comprising electrical resistance type strain gauges connected to a suitable electronic display, or a 15 pressure cell connected to a pressure gauge or other display.

4

Claims

1. A noseweight measuring device incorporated into th6 jockey wheel assembly of a 5 towed vehicle.

2. A device as defined in claim I comprising a calibrated spring incorporated within the jockey wheel assembly to measure the noseweight.

3. A device as defined in claim 2 wherein a scale indicates the noseweight measurement derived from the spring.

4. A device as defined in claim 2 or 3 comprising a pair of telescopically interfitted tubes used to house the spring and a threaded nut for co-operation with a threaded stem used to raise and lower a jockey wheel.

5. A device as defined in claim 4 wherein the threaded stem is held axially fixed 20 relative to a drawbar of the vehicle.

6. A device as defined in any preceding claim wherein a locking peg enables the jockey wheel to be retained in a retracted position when not in use.

7. A noseweight indicating jockey wheel assembly substantially as described with reference to or as shown in the drawings.