Down pressure control mechanism for grain drills
First Claim
1. A furrow opener assembly for a grain drill or the like having a main frame, a subframe movably mounted to said main frame and including a furrow opener member, said mounting of said subframe permitting movement of said furrow opener to a working position with the furrow opener member in the ground and upwardly therefrom, and means to resiliently resist upward movement of said furrow opener member and said subframe comprising a linkage means operably connected between said main frame and said subframe, spring means connected to said linkage means, means guiding said linkage means in a desired path of movement as said subframe moves upwardly, said means guiding include a first working position guide section and a second guide section, said spring means resisting upward movement of the subframe through said linkage means at a first rate when the linkage means is guided in the working position guide section, and at a second substantially lower rate for each increment of upward movement of the subframe when the linkage means is guided in the second guide section after upward movement of said subframe from its working position.
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Accused Products
Abstract
A down pressure control for use with furrow openers in grain drills which provides a spring load for maintaining down pressure on the furrow opener during normal operating conditions and which can be at relatively high rate to permit minimum tillage, or work in hard ground, but yet will release upon excessive movement of the furrow opener to prevent overstressing the hold down springs. The down pressure control is used in combination with an individual depth control for each of the furrow openers to insure that each furrow opener is individually controlled as to down pressure and depth.
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Citations
15 Claims
- 1. A furrow opener assembly for a grain drill or the like having a main frame, a subframe movably mounted to said main frame and including a furrow opener member, said mounting of said subframe permitting movement of said furrow opener to a working position with the furrow opener member in the ground and upwardly therefrom, and means to resiliently resist upward movement of said furrow opener member and said subframe comprising a linkage means operably connected between said main frame and said subframe, spring means connected to said linkage means, means guiding said linkage means in a desired path of movement as said subframe moves upwardly, said means guiding include a first working position guide section and a second guide section, said spring means resisting upward movement of the subframe through said linkage means at a first rate when the linkage means is guided in the working position guide section, and at a second substantially lower rate for each increment of upward movement of the subframe when the linkage means is guided in the second guide section after upward movement of said subframe from its working position.
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6. In a furrow opener assembly for a grain drill or the like, a main frame, a subframe pivotally mounted to said main frame and including a furrow opener member, said pivotal mounting of said subframe permitting movement of said furrow opener member relative to the ground, and means to resiliently resist upward movement of said furrow opener member and said subframe about said pivotal mounting of said subframe comprising a linkage means operably connected between said main frame and said subframe, spring means connected to said linkage means, means guiding said linkage means in a path of movement as said subframe pivots, said means guiding including a first working position guide section and a second guide section, said linkage means loading said spring means at a first rate for each degree of upward pivoting of the subframe with the linkage means guided in the working guide section, and at a second rate which loads the spring means at a substantially lower rate for each degree of pivoting of the subframe with the linkage means guided in the second guide section after substantial upward pivoting of said subframe.
Specification