Tool control system for agricultural seeders

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 the tool bar of the frame so that the 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 seeding element including a ground opener for cutting a furrow into the surface of the ground;
• each seeding element including a packer wheel behind the ground opener for rolling along the ground at least partly in the furrow mounted in a set relationship to the ground opener;
• each seeding element being mounted on the tool bar for up and down floating movement relative to the frame independently of the other seeding elements;
• a gauge wheel mounted on the tool bar for running on a surface of the ground;
• a first sensor for providing a first signal indicative of a height from the tool bar of the packer wheel as it runs in the furrow;
• and a second sensor for providing a second signal indicative a height from the tool bar of the gauge wheel as it runs on the ground.

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 the tool bar of the frame so that the 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 seeding element including a ground opener for cutting a furrow into the surface of the ground;
• each seeding element including a packer wheel behind the ground opener for rolling along the ground at least partly in the furrow mounted in a set relationship to the ground opener;
• each seeding element being mounted on the tool bar for up and down floating movement relative to the frame independently of the other seeding elements;
• a visual display for an operator of the seeder which provides a plurality of selectable depths of penetration of the packer wheel from the ground surface for selection by the operator;
• an input device operable by the operator of the seeder for changing the selected substantially constant depth of penetration of the packer wheel from the ground surface;
• a control system arranged to keep the depth of penetration of the packer wheel from the ground surface at said selected substantially constant value.