Parallel linkage opener with adjustable spring loaded packer wheel

摘要

An seeder includes a frame on ground wheels defining tool bars for seeding elements spaced across the frame. Each element includes a pair of parallel arms connected to the tool bar bracket forming a parallel linkage for up and down movement of a support arm connected at a rear end and carrying the packer wheel. A spring applies a downward spring force on the parallel linkage to apply a downward force on the packer wheel so that the spring force increases as the parallel arms pivot upwardly and decreases as the parallel arms pivot downwardly. A control device is arranged to raise and lower the tool bar in response to a detected value of a sensor so as to change the angle of the parallel linkage and change the spring force. A cam controlled double rack adjustment of the height of the opener allows the user to change seeding depth.

主权项

1. An agricultural seeder comprising:
a frame having at least one tool bar; ground wheels for supporting the frame for transportation in a direction of working movement across ground to be seeded; a plurality of seeding elements each including a bracket mounted on said at least one tool bar of the frame so that said plurality of seeding elements are arranged at spaced positions across the width of the frame for applying seeds to the ground as the frame is moved across the ground; each of said plurality of seeding elements including a ground opener for cutting a furrow into the surface of the ground; each of said plurality of seeding elements including a packer wheel behind the ground opener for rolling along the ground at or adjacent to the furrow; each of said plurality of seeding elements being mounted on said at least one tool bar for up and down floating movement relative to the frame independently of the other seeding elements; each of said plurality of seeding elements including a pair of parallel arms connected to the bracket and extending rearwardly therefrom to form a parallel linkage for said up and down floating pivotal movement relative to said at least one tool bar to different angles of the parallel linkage relative to the ground; each of said plurality of seeding elements including a rearwardly extending support arm connected at a rear end of the parallel arms and carrying the packer wheel such that the packer wheel can move upwardly and downwardly relative to said at least one tool bar; a spring arrangement extending between a component connected to said at least one tool bar and said parallel linkage and applying a downward spring force on said parallel linkage relative to said at least one tool bar on the parallel linkage and arranged to flex to provide said floating movement of said parallel linkage relative to said at least one tool bar to apply a downward force on the packer wheel, the spring arrangement being arranged such that the spring force increases as the parallel arms pivot upwardly and decreases as the parallel arms pivot downwardly; and a control device arranged to raise and lower said at least one tool bar relative to the ground so as to change the angle of the parallel linkage relative to the ground so as to change the downward spring force generated by said spring arrangement.