Floating marker arm mechanism

A marker-arm mechanism mountable on a wheeled implement having a frame for forming a marker furrow in the ground, the marker-arm mechanism comprising:

• marker-disc means for forming the marker furrow;
• foldable marker-arm means having an upper arm rotatably mounted at one end thereof on a pivot carried by the frame and having a forearm carrying the marker-disc means pivotally connected to the other end of the upper arm, for extending the marker-disc means away from the wheeled implement;
• means for adjustably and removably mounting a base to the frame comprising means carrying a second pivot on the first pivot;
• and
• actuation means carried by the upper arm and the base for causing the marker-arm means to extend the marker-disc means away from the implement and to contact the ground for forming the marker furrow and for causing the marker-arm means to retract the marker-disc means from the ground and to draw the marker-disc means inwardly toward the implement;
• and
• means for mounting the upper arm to the base including stop means carried by the base and abuttingly engageable by the pivot mounting means to allow for rotative movement of the marker-arm means between first and second positions relative to the pivot and resiliently urging the marker-disc means substantially to follow ground-surface contours for forming the marker furrow.

A marker-arm mechanism mountable on a wheeled implement having a frame for forming a marker furrow in the ground, the marker-arm mechanism comprising:

• a base adjustably and removably mounted on the frame;
• a marker-disc means for forming the marker furrow;
• foldable marker-arm means having an upper arm rotatably mounted at one end thereof on a pivot carried by the frame and having a forearm carrying the marker-disc means pivotally connected to the other end of the upper arm for extending the marker-disc means away from the wheel implement;
• actuation means carried by the upper arm and the base for causing the marker-arm means to extend the marker-disc means away from the implement and to contact the ground for forming the marker furrow and for causing the marker-arm means to retract the marker-disc means from the ground and to draw the marker-disc means inwardly toward the implement;
• means carried by the base and mounted on the marker-arm means for causing the marker-arm means to fold when retracting the marker-disc means from the ground and for causing the marker-arm means to straighten when extending the marker-disc means away from the wheeled implement;
• means mounted on the upper arm for preventing shock contact by the forearm;
• means for mounting the upper arm to the base to allow for rotative movement of the marker-arm means between first and second positions relative to the pivot and resiliently urging the marker-disc means substantially to follow ground-surface contours for forming the marker furrow, and
• shearable means including a shear pin and a foldable hinge joint both mounted on the upper arm, to allow the upper arm to fold along the hinge joint when lateral movement of the marker-arm means relative to the ground is restrained by a predetermined force.