US Patent 9315971 Retainer systems for ground engaging tools

Disclosed are various exemplary embodiments of a retainer bushing for use with a lock of a ground engaging tool. The retainer bushing may include a skirt extending around a retainer axis, where the skirt may include an outer surface configured to mate with a lock cavity of the ground engaging tool and an inner surface configured to rotatably receive an outer surface of the lock. The retainer bushing may also include a detent projection extending radially inward from the inner surface and configured to engage a detent recess of the lock to resist rotation of the lock. The skirt and the detent projection may be integrally constructed of a thermoplastic material comprising polyoxymethylene.