A mechanical coupling arrangement for interconnecting a compression spring assembly and certain working tools such as the disks of an agricultural tillage implement includes a hinge having a pivot axis and first and second arms extending from the pivot axis. Linkage arrangements couple the first hinge arm to the spring assembly and the second hinge arm to the working tools. A shear pin extends between the hinge arms remote from the pivot axis for fixing the angular relationship between the arms so long as the spring compression remains less than a predetermined maximum. Shear pin failure allows one hinge arm to pivot relative to the other when the predetermined maximum tension is exceeded uncoupling the spring assembly from the tools.
