| 摘要 |
A sowing disk consists of two metal circles, fixed between each other and having the joint rotational axis, in particular the base with undervacuum openings and cover plates with sucking openings. In the cover plate the double amount of the sucking openings, of two different sizes, is made, and each of the cover plates themselves is made in such a manner as to allow rotating as regards to the base around the joint rotational axis.
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