| 摘要 |
An improved earthworking implement which includes a frame, a standard pivotally attached to the frame, an earthworking tool and a shank pivotally attached to the lower portion of the standard, stops to limit pivotal movement of the standard and the earthworking tool, and a spring trip device to position the standard in a lower working position, to absorb energy and to release and allow the earthworking tool to move up and to the rear when the earthworking tool strikes an obstruction. The spring trip device includes a first bar assembly with a leaf spring pivotally attached to the frame for pivotal movement about a first axis, a second bar assembly with a leaf spring pivotally attached to the shank for pivotal movement about a second axis which is in the same plane as the first axis, and a pin means to pivotally attach the first bar assembly to the second bar assembly for pivotal movement relative to the second bar assembly about an axis which is parallel to and spaced to one side of the plane containing the first axis and the second axis when the standard is in the working position. Stops are provided to limit movement of the pin means, for attaching the first bar assembly to the second bar assembly, away from the plane containing the first and second axis when the standard is in the working position. An abutment surface on the first bar assembly contacts an abutment surface on the second bar assembly, after the trip assembly has been loaded and the leaf springs have been deformed a certain amount, to limit pivotal movement of one bar assembly relative to the other bar assembly. A relative small increase of the force on the earthworking tool after the abutment surfaces make contact causes bar assemblies to move rapidly away from stops. A resilient cantilevered beam is rigidly attached to one of the bar assemblies, and engages a surface on the other bar assembly. By adjusting the force which the cantilevered beam exerts on the bar assemblies, the force required to trip the spring trip assembly can be adjusted.
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