08544398 is referenced by 25 patents and cites 305 patents.

In one embodiment, an agricultural row unit for use with a towing frame hitched to a tractor includes an attachment frame adapted to be rigidly connected to the towing frame. A support member is pivotably coupled to the attachment frame to permit vertical pivoting movement of the support member relative to the attachment frame, and at least one furrow-closing device is mounted on the support member. A hydraulic cylinder is coupled to the support member for urging the row unit frame downwardly toward the soil. The hydraulic cylinder includes a movable ram extending into the cylinder, and a hydraulic-fluid cavity within the cylinder for receiving pressurized hydraulic fluid for urging the ram in a first direction that pivots the support member in a first vertical direction. An accumulator has a fluid chamber containing a pressurized gas for urging the ram in a second direction that pivots the support member in a second vertical direction.

Hydraulic down pressure control system for closing wheels of an agricultural implement
Application Number
Publication Number
8544398 (B2)
Application Date
March 30, 2011
Publication Date
October 1, 2013
Joseph D Bassett
Nixon Peabody
Dawn Equipment Company
A01B 23/06
A01B 15/18
A01B 15/16
A01B 15/14
A01B 7/00
A01B 5/10
A01B 63/32
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