Directive 94/20/EC of the European Parliament and of the Council (repealed)Show full title

3. DRAWBAR COUPLINGS

The requirements of Sections 3.1 to 3.8 are applicable to all drawbar couplings of Class C 50. Section 3.9 lists the additional requirements which must be fulfilled by standard drawbar couplings of Classes C 50-1 to C 50-6.

3.1. Load requirements

All drawbar couplings shall be able to satisfy the tests stated in Annex VI, Section 4.3.

3.2. Suitable drawbar eyes

Class C 50 drawbar couplings shall be compatible with all Class D 50 drawbar eyes and coupling with the specified characteristics.

3.3. Automatic operation

Drawbar couplings must be automatic in operation (see Annex I, Section 2.1.17).

3.4. Jaw

Class C 50 drawbar couplings must have a jaw which is designed such that the appropriate drawbar eyes is guided into the coupling.

If the jaw, or a part supporting the jaw, can pivot about the vertical axis, it must establish itself automatically in the normal position and, with the coupling pin open, be effectively restrained in this position to give satisfactory guidance for the drawbar eye during the coupling procedure.

If the jaw, or a part supporting the jaw, can pivot about the transverse axis, the joint providing the rotation capability must be restrained in its normal position by a locking torque. This torque must be sufficient to prevent a force of 200 N acting vertically upwards on the top of the jaw producing any deflection of the joint from its normal position. It must be possible to bring the jaw to its normal position manually. A jaw that pivots about the transverse axis is only approved for vertical bearing loads S of up to 50 kg and a V-value of up to 5 kN.

If the jaw, or a part supporting the jaw, is pivoted about the longitudinal axis, the rotation must be restrained by a locking torque of at least 100 Nm.

The minimum required size of the jaw depends on the D value of the coupling:

	D-value	≤ 18 kN:	width 150 mm, height 100 mm
18 kN <	D-value	≤ 25 kN:	width 280 mm, height 170 mm
25 kN <	D-value:		width 360 mm, height 200 mm

The external corners of the jaw may be radiused.

Smaller jaws are permitted for Class C 50-X drawbar coupling if their use is restricted to centre-axle trailers up to 3,5 tonnes maximum permissible mass or if the use of a jaw from the above table is impossible due to technical reasons and if, furthermore, there are special circumstances such as visual aids for ensuring safe execution of the automatic coupling procedure and if the field of application is restricted in the approval according to Annex III.

3.5. Minimum freedom of movement of the coupled drawbar eye

The coupled drawbar eye must be able to rotate horizontally ± 90^o about the vertical axis from the longitudinal axis of the vehicle (see Figure 5). The coupled drawbar eye must be able to rotate vertically ± 20^o about the transverse axis from the horizontal plane of the vehicle (see Figure 6). If the motion is provided by a special joint (only on Class C 50-X drawbar couplings) the field of application given in the approval according to Annex III must be restricted to the cases stated in Annex VII, Section 2.3.7. It must be possible for the coupled drawbar eye to be rotated axially ± 25^o about the longitudinal axis from the horizontal plane of the vehicle (see Figure 7).

The stated angles of rotation are applicable to drawbar couplings not attached to the vehicle.

3.6. Minimum angle for coupling-up and uncoupling

Coupling and uncoupling of the drawbar eye must also be possible when the longitudinal axis of the drawbar eye in relation to the centreline of the jaw:

3.6.1.

is rotated 50^o horizontally to right or left;

3.6.2.

is rotated 6^o vertically up or down;

3.6.3.

is rotated 6^o axially to right or left.

3.7. Locking to prevent inadvertent uncoupling

In the closed position the coupling pin must be secured by two positive mechanical securing devices each of which must remain effective should the other fail.

The closed and secured position of the coupling must be clearly indicated externally by a mechanical device. It must be possible to verify the position of the indicator by feel, e. g. in the dark.

The mechanical device must indicate the engagement of both locking devices (an AND condition).

However, it is sufficient for the engagement of only one locking device to be indicated if, in this situation, engagement of the second locking device is an inherent feature of the design.

3.8. Hand levers

Hand levers must be of a design suitable for easy use with the end rounded off. The coupling must have no sharp edges or points of possible pinching near the hand lever which could result in injury during operation of the coupling. The force needed to release the coupling, measured without the drawbar eye, must not exceed 250 N perpendicular to the hand lever along the line of operation.

3.9. Special requirements for standard drawbar couplings of Class C 50-1 to C 50-6.

3.9.1. The swivel motion of the drawbar eye about the transverse axis must be achieved through the spherical shape of the coupling pin (and not by means of a joint, see Figure 6).

3.9.2. Tensile and compressive shock loads along the longitudinal axis due to the clearance between the coupling pin and the drawbar eye must be attenuated by spring and/or damping devices (except C 50-1).

3.9.3. The dimensions given in Figure 8 and Table 3 must be adhered to.

3.9.4. The couplings must be suitable and tested for the characteristic values given in Table 4.

3.9.5. The coupling must be opened by means of a hand lever at the coupling (no remote control).

TABLE 3
Dimensions of standard drawbar couplings (mm) (see Figure 8)
	C 50-1	C 50-2	C 50-3	C 50-4	C 50-5	C 50-6	Remarks
e1	83		120	140	160		± 0,5
e2	56		55	80	100		± 0,5
d1	—	54	74	84	94		maximum
d2	10,5		15	17	21		H13
f	110		155	180	200		+6,-0
g	85		90	120	140		±3
a	100	170	200	200	200		+20,-0
b	150	280	360	360	360		+20,-0
c	20		24	30	30		maximum
h	150	190	265	265	265		maximum
l1	—	150	250	300	300		maximum
12	150	300	330	330	330		maximum
l3	100	160	180	180	180		±20
T	—	15	20	35	35		maximum

TABLE 4
Characteristic values for standard drawbar couplings:
D = maximum D value (kN) Dc = maximum D value (kN) for centre-axle trailers S = maximum static vertical bearing load (kg) V = maximum V-value (kN)
	C 50-1	C 50-2	C 50-3	C 50-4	C 50-5	C 50-6
D	18	25	70	100	130	190
Dc	18	25	50	70	90	120
S	200	250	650	900	1 000	1 000
V	12	10	18	25	35	50