Spring trip standard having reduced spring buckling forces

摘要

A spring trip standard for a tillage implement includes a coil spring compressed between an upper spring-abutting surface on the mounting bracket and a lower spring abutment surface on a casting which is connected by a transverse pivot to the mounting bracket. The casting includes an integral stop extending forwardly from the pivot and contacting the bottom of the bracket when the shank is in the ground working position so that a tension link between the bracket and casting is eliminated. The casting includes a spring abutment surface having a first portion which extends generally perpendicular to the spring axis to support the lowermost end of the spring when the shank is stopped in the normal working position. The opposite side of the spring abutment surface is angled relative to the first portion, and the lowermost coil of the compressed spring, when the standard is in the tripped position, abuts the opposite side to maintain the spring in a non-buckling state. The lowermost coil is maintained generally perpendicular to the centerline of the coil spring in the field-working and tripped positions so that spring buckling and spring fatigue caused by buckling are reduced or eliminated.