Foldable boom for an agricultural sprayer

A folding boom for an agricultural sprayer, the boom comprising:

• a first boom piece pivotally connected to a second boom piece at a pivot region which allows the first and second pieces to be pivoted between a folded orientation and an extended orientation,
• a hydraulic cylinder for hydraulically pivoting the first boom piece relative to the second boom piece between the folded orientation and the extended orientation, the hydraulic cylinder including a cylinder portion in which a piston structure is mounted, the cylinder portion and the piston structure being configured to slide axially relative to one another when the first boom piece is pivoted relative to the second boom piece;
• and
• an accumulator in fluid communication with the cylinder portion for:
• a accumulating hydraulic fluid under pressure when the first boom piece collides with an obstruction and is pivoted in a rearward direction from the extended orientation toward the folded orientation;
• and b) forcing the pressurized hydraulic fluid from the accumulator toward the hydraulic cylinder after the obstruction has been bypassed, wherein the accumulator automatically causes the first boom piece to return to the extended orientation after the obstacle has been bypassed by providing stored hydraulic pressure to the hydraulic cylinder which forces the hydraulic cylinder to pivot the first boom piece in a forward direction to the extended orientation.

A method for providing a break-away function in a foldable agricultural spraying boom, the boom including an outer boom piece pivotally connected to an inner boom piece, the boom also including a hydraulic cylinder for hydraulically pivoting the outer boom piece relative to the inner boom piece between folded and extended positions, the hydraulic cylinder including a piston structure mounted within a cylinder portion, the piston structure and the cylinder portion being configured to slide axially relative to one another when the outer boom piece is pivoted between the folded and extended positions, the spraying boom including a hydraulic control system for controlling the operation of the hydraulic cylinder, the hydraulic control system being operable in an unfold mode in which hydraulic pressure from a pressure source causes the hydraulic cylinder to move the outer boom piece from the folded position toward the extended position, the hydraulic control system also being operable in a fold mode in which hydraulic pressure from the pressure source causes the hydraulic cylinder to move the outer boom piece from the extended position toward the folded position, and the hydraulic control system also being operable in a neutral mode in which the pressure source is prevented from extending or retracting the hydraulic cylinder, the method comprising:

• moving the boom in a forward direction with the outer boom piece in the extended position;
• contacting the outer boom piece with an obstruction while the boom is moved in the forward direction such that a force is applied to the outer boom piece that pushes the outer boom piece rearwardly from the extended position toward the folded position;
• transferring the force from the outer boom piece to the hydraulic cylinder;
• sliding the piston structure and the cylinder portion axially relative to one another in response to the force transferred to the hydraulic cylinder through the outer boom piece, wherein the relative axial movement of the piston structure and the cylinder portion allows the outer boom piece to pivot rearwardly toward the folded position until the obstruction is bypassed;
• moving the outer boom piece forwardly to the extended position after the obstruction has been bypassed by sliding the piston structure and the cylinder portion relative to one another;
• and
• operating the hydraulic control system exclusively in the neutral mode as the piston structure and the cylinder portion slide relative to one another to cause the outer boom piece to move forwardly to the extended position after the obstruction has been bypassed.

A method for providing a break-away function in an agricultural spraying boom, the boom including a boom piece pivotally moveable between folded and extended positions, the boom also including a hydraulic cylinder for hydraulically pivoting the boom piece between the folded and extended positions, the hydraulic cylinder including a piston structure mounted within a cylinder portion, the piston structure and the cylinder portion being configured to slide axially relative to one another when the boom piece is pivoted between the folded and extended positions, the spraying boom including a hydraulic control system for controlling the operation of the hydraulic cylinder, the hydraulic control system being operable in a first mode in which hydraulic pressure from a main pressure source causes the hydraulic cylinder to move the boom piece forwardly from the folded position toward the extended position, the hydraulic control system also being operable in a second mode in which hydraulic pressure from the main pressure source causes the hydraulic cylinder to move the boom piece rearwardly from the extended position toward the folded position, the method comprising:

• moving the boom piece forwardly with the boom piece in the extended position;
• contacting the boom piece with an obstruction as the boom piece is moved forwardly such that a force is applied to the boom piece that pushes the boom piece rearwardly from the extended position toward the folded position;
• transferring the force from the boom piece to the hydraulic cylinder;
• sliding the piston structure and the cylinder portion axially relative to one another in response to the force transferred to the hydraulic cylinder through the boom piece, wherein the relative axial movement of the piston structure and the cylinder portion allows the boom piece to pivot rearwardly toward the folded position until the obstruction is bypassed;
• and
• returning the boom piece forwardly to the extended position after the obstruction has been bypassed by sliding the piston structure and the cylinder portion relative to one another without using pressure from the main pressure source.