| 主权项 |
1. A boom arm with a bi-directional break-away apparatus, the boom arm comprising a main boom portion and a boom tip, the break-away apparatus being positioned at a joint between the main boom portion and the boom tip, the break-away apparatus allowing the boom tip to assume a neutral position and to pivot to a forward position and to a rearward position with respect to the main boom portion, the break-away apparatus comprising:
a first plate disposed at the joint, the first plate is attached to the main boom portion; a second plate disposed at the joint, the second plate is attached to the boom tip; a hinge assembly positioned between the first plate and the second plate, the hinge assembly comprising a hinge pin having a longitudinal axis, wherein the hinge pin is rotationally fixed to the first plate so that the hinge pin is prevented from rotating relative the first plate; wherein the first and second plates are in a first position with respect to each other when the boom tip assumes the neutral position, and wherein the first and second plates are movable with respect to each other about the longitudinal axis to pivot the boom tip to a forward position and to a rearward position; a pair of torsion springs configured to return the first and second plates to the first position after the first and second plates move from the first position, wherein the first torsion spring is configured to return the first and second plates to the first position after the boom tip pivots to a forward position, and wherein the second torsion spring is configured to return the first and second plates to the first position after the boom tip pivots to a rearward position; and a rotary damper that controls return of the first and second plates to the first position from the forward and rearward positions, wherein a housing of the rotary damper is attached to the second plate, and wherein a stud of the rotary damper is fixed to the hinge pin so that the hinge pin is prevented from rotating relative the stud. |
