Breakaway mechanism for a row marker

In an implement having a frame with a front and rear portion, a support arm, means for pivotably attaching the support arm to the frame along a first axis, and breakaway means operatively attached to said frame generally at a point of attachment forward of said pivot means for releasably holding said support arm from pivoting about said first axis with respect to said frame;

• the improvement comprising:
• said breakaway means including an elongated member, having a longitudinal axis, operatively connected to said frame, said longitudinal axis being substantially perpendicularly disposed with respect to said first axis and generally tangential to an arc formed by rotation of said point of attachment about said first axis whereby when said support arm hits an obstruction said support arm will tend to be pivoted about said first axis and tension forces will be applied to said elongated member, and wherein said elongated member has a tensile strength of a predetermined amount to allow the elongated member to fracture before the support arm is damaged due to contact with such obstruction;
• said breakaway means further comprising aperture means for effectively forming an opening in the frame and an elongated sleeve disposed in said opening, said sleeve having a hole therethrough, said elongated member being disposed through said hole whereby a substantial portion of said elongated member will be encircled by said sleeve and whereby shearing forces applied to the elongated member from the sleeve due to vibration or the like will be minimized;
• sleeve fastener means disposed on one side of side aperture means for releasably holding said sleeve into said opening, a portion on the other end of the sleeve being larger than said opening for preventing loss of the sleeve when the elongated member is fractured, said sleeve fastener means including threads on the outside of said sleeve and at least one matching threaded nut for engagement with said threads on the sleeve.

In an implement having a frame, a support arm, means for pivotably attaching the support arm to the frame along a first axis, and breakaway means operatively attached to said frame generally at a point of attachment forward of said pivot means for releasably holding said support arm from pivoting about said first axis with respct to said frame;

• the improved breakaway means comprising:
• an elongated member, having a longitudinal axis, operatively connected to said frame, said longitudinal axis being substantially perpendicularly disposed with respect to said first axis and generally tangential to an arc formed by rotation of said point of attachment about said first axis whereby when said support arm hits an obstruction said support arm will tend to be pivoted about said first axis and tension forces will be applied to said elongated member, and wherein said elongated member has a tensile strength of a predetermined amount to allow the elongated member to fracture before the support arm is damaged due to contact with such obstruction;
• aperture means for effectively forming an opening in the frame and an elongated sleeve disposed in said opening, said sleeve having a hole therethrough, said elongated member being disposed through said hole whereby a substantial portion of said elongated member will be encircled by said sleeve and whereby shearing forces applied to the elongated member from the sleeve due to vibration or the like will be minimized;
• and
• a bracket means operatively pivotally attached to said frame, said bracket means also being attached to said elongated member for preventing substantial bending of the elongated member when the support arm hits an obstruction, said bracket means including a block having a slot formed therein, said slot including a first seat area disposed to receive a portion of said elongated member and a second seat area disposed to receive a portion of said sleeve.