Many serious or even fatal accidents occur when tools are not correctly interlocked with the quick coupler on construction machinery. In the majority of quick coupler systems, the tool is locked in place on the side facing away from the operator who is not therefore able to see whether the pins are correctly extended, i.e.
According to Dr. Michael Thierbach of KAN, “the EU Machinery Directive requires reasonably foreseeable misuse to be considered during the risk analysis. In this case, it has not been given adequate consideration”. EN 474-1, the current harmonized standard governing earth-moving machinery, sets out requirements for quick couplers. These requirements have been revised and will be replaced in the near future by a reference to the international ISO 13031 standard, Quick couplers. Although some requirements have been improved, the test by the operator still forms part of the safety concept.
Occupational safety and health institutions and market surveillance authorities in several European countries consider the state of the art now to be more advanced than that described in the standards. Quick couplers are available on the market that provide the operator with clear information on the locking state. Design solutions also exist that reduce the likelihood of the tool dropping should it not be locked correctly in position. These solutions enable the operator to detect the fault in time and take appropriate measures.
The European market surveillance authorities’ Administrative Co-operation Working Group (ADCO) with responsibility for earth-moving machinery has therefore formulated key points for amendments that need to be made to the standard in order to make quick couplers safer and consistent with the Machinery Directive. In the interests of speedy implementation, direct incorporation into the European standard is favoured.