Bushing for mounting a laterally adjustable pivot arm
A bushing is provided for mounting a pivot arm that has both a threaded portion as well as one or two smooth cylindrical portions. The threaded portion enables the pivot arm to be a laterally adjusted by rotating the bushing while the smooth portion or portions provide a bearing surface or surfaces for the pivot arm loads. This removes the load from the threads, reducing wear of both the bushing and the pivot arm, thereby reducing maintenance cost.
1. A row unit for an implement comprising:
a frame with a threaded hole therein;
a depth control member;
a pivot arm having one end coupled to the depth control member and a bushing block at the other end for pivotally mounting the pivot arm to the frame, the bushing block having a bore therethrough, a portion of the bore being threaded and at least one portion of the bore being smooth;
a bushing having a cylindrical body with a head at one end and a through bore, the cylindrical body further having a cylindrical surface with threads on a portion thereof for engagement with the threads in the bore of the bushing block and at least one portion of the cylindrical surface being smooth for engagement with the smooth portion of the bore in the mounting block; and
a mounting bolt having a head at one end, the bolt extending through the bore in the bushing with the bolt head adjacent to the head of the bushing and extending beyond a distal end of the bushing opposite the bushing head for insertion into the threaded hole in the frame to mount the bushing to the frame and prevent rotation of the bushing about the mounting bolt, with the bushing block and pivot arm being rotatably supported on the bushing.
2. The row unit as defined by claim 1 wherein the bore in the bushing block has first and second smooth portions on opposite sides of the threaded portion and the bushing has first and second smooth portions on opposite sides of the threaded portion for engagement with the first and second smooth portions of the bore in the mounting block.