Overview
ISO 24347:2019 specifies the dimensions, location and vertical loading for an 80 mm nominal diameter ball coupling device used to mechanically connect a towed, non-balanced implement to an agricultural towing vehicle. The standard ensures interchangeability and safe attachment by defining the ball, trailer shank, keeper arrangement, clearance zones and two design versions: close position and horizontal adjustable.
Key topics and technical requirements
- Ball coupling size and marking
- Nominal ball diameter: 80 mm.
- The coupling shall be permanently marked “80 mm”; the mating trailer connection must show a visible size identification.
- Geometry and keeper
- Keeper-to-ball-centre distance: (65 ± 1) mm; keeper must be adjustable for wear.
- Detailed ball and trailer shank dimensions and flange/weld options are provided (see Annex A).
- Articulation and clearance
- Coupling must allow freedom of rotation with minimum articulation angles:
- Yaw (A): ≥ 60° (some positions ≥ 90°)
- Pitch (B): ≥ 20° (30° recommended)
- Roll (C): ≥ 20°
- Minimum clearance zones defined to avoid interference with PTO and driveline.
- Location relative to PTO
- Ball mounted in the vertical plane of the vehicle longitudinal axis.
- Upper location permitted only for the close position version.
- Dimensional locations (T and V) given for close position and short/regular/extended horizontal positions.
- Example values (close position): T = 50–250 mm; V min = 120 mm (PTO 1 & 2) or 145 mm (PTO 3 & 4).
- Horizontal adjustable positions: short/regular/extended positions and V minima (see standard for full table).
- Vertical loading limits
- Close position: maximum static vertical downward load = 40 kN.
- Horizontal adjustable: tabulated depending on PTO type and ball position (e.g., PTO 1&2: short 27 kN, regular 18 kN, extended 13 kN; PTO 3&4: short 33 kN, regular 22 kN, extended 16 kN).
- Upward loading (uploading) is not recommended.
Applications and users
ISO 24347:2019 is relevant for:
- Manufacturers of ball couplings, trailer shanks and tractor mounting assemblies.
- Tractor and implement designers ensuring mechanical compatibility and safe attachment.
- Test laboratories, certification bodies and conformity assessors verifying compliance.
- Fleet managers, service technicians and procurement specialists selecting interoperable coupling systems.
- Improves safety where PTOs and driveline clearance zones must be coordinated with towing connections.
Related standards
Keywords: ISO 24347:2019, ball coupling device 80 mm, agricultural vehicles, trailer shank dimensions, PTO clearance, vertical load limits, coupling keeper, close position, horizontal adjustable.
Open preview (PDF)Agricultural vehicles — Mechanical connections between towed and towing vehicles — Dimensions of ball coupling device (80 mm)