Patent ID: 7631817

Claim:
A boom lock assembly for an agricultural sprayer, the sprayer having a four bar linkage lift linkage for raising a carrying frame in support of a boom from a lowered, operative position to a raised, inoperative position for the boom to pivot from an extended position to a folded position for transport, comprising: said four bar parallel lift linkage includes an upper and lower link member; wherein one end of said upper and lower link member is pivotally attached to a main frame; wherein opposing end of said upper and lower link member is attached to said carrying frame; a lift actuator is connected to a lower end of said lower link member and connected to said carrying frame; a lock pin mounted at the carrying frame; a compression spring is mounted on said lock pin; a support member attached at the lock pin and positioned to engage one end of the spring; a lock plate mounted at an upper end of said lower link member, the lock plate having an elongated slot; wherein upon the four bar parallel lift linkage raising the carrying frame and the boom to the raised position, the slot of the lock plate at the four bar parallel lift linkage aligns to receive the lock pin at the carrying frame, and wherein as the boom pivots about a vertical axis and swings the boom horizontally toward the folded position, the boom urges the lock pin in a linear motion through the slot to a locked position so as to secure the four bar parallel lift linkage and the boom in the raised position; wherein said compression spring biases the lock pin to an unlocked position; wherein upon said boom pivoting from the folded position toward the extended position, the compression spring biases the lock pin to retract from the slot of the lock plate such that the lift linkage is allowed to operate freely.