ISO 13052:2013

INTERNATIONAL ISO
STANDARD 13052
First edition
2013-11-01
Road vehicles — Trailers up to 3,5 t —
Requirements for jockey wheels and
drawbar supports
Véhicules routiers — Remorques jusqu’à 3,5 t — Exigences pour roues
jockey et supports de barres d’attelage
Reference number
©
ISO 2013
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The committee responsible for this document is ISO/TC 22, Road vehicles, Subcommittee SC 4, Exterior
fittings of car/trailer-caravan combinations.
INTERNATIONAL STANDARD ISO 13052:2013(E)
Road vehicles — Trailers up to 3,5 t — Requirements for
jockey wheels and drawbar supports
1 Scope
This International Standard is intended to define safety requirements which apply to jockey wheels and
drawbar supports provided to support the single axle (centre axle) rigid drawbar trailers nose weight
with a technically permissible maximum laden mass not more than 3,5 tons.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
jockey wheel
device usually mounted on the front of the trailer to support the nose weight of the trailer and to adjust
the height of the drawbar if not connected
Note 1 to entry: This device permits the movement of the trailer in any direction at steady-state without the use
of a towing road vehicle.
2.2
drawbar support device
device fastened to the drawbar with height-adjustable mechanism, retaining the trailer in horizontal
position when being disconnected to the towing vehicle
Note 1 to entry: Built up with a vertical tubular strut and adjustable height provided with a blocking system
and/or clamping system activated by handle operation.
Note 2 to entry: When this device is equipped with a lift system, uncoupling the axle of the coupling ball to the
coupling ball shall be permitted.
2.3
nose mass
mass on the coupling point which is needed to hold the trailer in horizontal position
Note 1 to entry: The S value is the vertical mass, in kilograms, imposed on the coupling, under static conditions,
by the centre axle trailer, as defined in ECE R55–01 paragraph 2.13, of technically permissible maximum mass.
2.4
vertical static load
vertical load applied to the coupling device of the towing vehicle expressed in Newton
2.5
nose weight
load holding up the drawbar support device when the trailer is uncoupled, with value depending on ratio
of the trailer coupling point distance on its axle expressed in Newton
2.6
lifting force
reacting force on the ground from the nose weight expressed in Newton
2.7
strut
adjustable tubular equipment holding up the nose weight, telescopic or not, fitted with a wheel or not
2.8
clamping system
device used to block the strut by a clamping ring and an operation handle or by a clamping set screw
Note 1 to entry: In these two cases, device shall insure blocking of the strut which supports the nose weight in
order to stabilize the uncoupled trailer in horizontal position.
2.9
coupling head
mechanical part fitted to the drawbar of trailers for connecting to the 50 mm diameter coupling ball on
the towing vehicle defined in ECE R55 article 2.6.2
2.10
drawbar eyes
mechanical part having a parallel hole suitable for a 50 mm diameter pin and fitted to the drawbar of
trailers for connecting to automatic drawbar couplings defined in ECE R55 article 2.6.4
2.11
load lifting capacity
maximum vertical mass, in kg, given by the manufacturer of the jockey wheel or the drawbar support
device which can be lifted
3 Jockey wheels – requirements
3.1 Markings
Each jockey wheel and drawbar support shall be permanently and clearly legibly marked with the
following information on a component that cannot be lost unintentionally and that cannot be removed
without tool:
— manufacturer’s identification;
— load lifting capacity.
3.2 Testing
The drawbar support device strength shall be tested by applying a load equal to two times the permissible
static vertical load value at the coupling head of the trailer as described in Formula (1):
Test load = 2 × permitted load lifting capacity
(1)
3.2.1 Calculation of the lifting force
The drawbar support device strength shall be tested by applying a load equal to two time
...