ISO 12140-2:2020

Overview - ISO 12140-2:2020 (Drawbar jacks, application safety)

ISO 12140-2:2020 specifies safety requirements, test methods and minimum acceptance criteria for telescopic mechanical (screw- and nut-type) and hydraulic drawbar jacks fitted to the implement tongue of interchangeable towed agricultural machinery. The standard covers implement-mounted jacks or jacks with an attachment mount used to support hitch points during storage, lifting/lowering of implement tongues, attachment/detachment from tractors, and levelling for stationary use.

Key topics and technical requirements

• Scope and applicability: Applies to implement-mounted drawbar jacks intended to couple with towing vehicles’ mechanical connections.
• Ground pressure: Average ground pressure at rated dynamic compressive load shall not exceed 760 kPa (exceptions for wheels/special bases intended for improved surfaces).
• Prevention of accidental movement: Jacks must be designed or fitted with devices to prevent unexpected winding or dropping while the implement is in motion.
• Security in operating/storage positions: Foldable or movable jacks must be lockable and secure in both storage and operating positions.
• Hydraulic safety: Hydraulic jack systems must comply with ISO 4413 requirements for hydraulic fluid power systems and components.
• Application performance and load criteria:
  • Static vertical load: Jack stand system must withstand 200% of the largest application vertical static load without functional or catastrophic failure.
  • Static side load: Must withstand 120% vertical load while a horizontal side load equal to 50% of the largest vertical static load is applied.
• Test methods (jack stand system application tests):
  • Installation per manufacturer instructions; new jacks for each test with optional 10-cycle break-in.
  • Ground contact pressure calculation formula provided (ρ = F/A).
  • Capacity tests include maximum static vertical and side-load procedures, with assessments for functional failure (e.g., inability to complete 10 loaded cycles) and catastrophic failure (structural failure, visible cracking, permanent deformation).
• Hydraulic load-holding test: With static compressive load extended to maximum, vertical height must not decrease more than 1 mm every 10 minutes over a 30-minute period.
• Marking/instructions: Adjustable mounts require affixed instruction signs near the jack mount indicating proper jack adjustment.

Practical applications and users

This standard is essential for:

• Implement manufacturers designing and specifying drawbar jacks and jack stand systems.
• Test laboratories and compliance engineers performing safety and acceptance testing.
• OEMs and suppliers of mechanical screw-type and hydraulic jacks for agricultural trailers and trailed equipment.
• Safety officers and fleet managers seeking to verify jack performance and reduce ground/structural failures.
• Regulatory bodies referencing harmonized test methods for market surveillance.

Related standards

• ISO 12140-1 (Design safety, test methods and acceptance criteria)
• ISO 4413 (Hydraulic fluid power - safety)
• ISO 6489, ISO 12934, ISO 24347 (mechanical connections and vocabulary for agricultural vehicles)

Keywords: ISO 12140-2, drawbar jacks, agricultural trailers, application safety, test methods, acceptance criteria, hydraulic jacks, mechanical screw jacks, jack stand system, ground pressure, static load testing.