US Patent 7549481 Parallel link mounting arm for a furrow opener

A trailing arm furrow opener apparatus includes a furrow opener bracket attached to the rear link of a parallel link assembly such that the furrow opener bracket and furrow opener attached thereto is maintained in a constant fore and aft angular orientation as the assembly moves up and down. A pucker wheel arm is fixed to one of the upper and lower parallel arm members of the parallel link assembly, and extends rearward from the rear link, and a packer wheel is mounted to the packer wheel arm. A bias device exerts a downward force on the assembly. The presentation angle of the furrow opener with respect to the ground is maintained constant while the assembly moves up and down.