초록 ▼

A center pivot irrigation machine having a swing arm for irrigating corner areas of a field. The swing arm has a steerable support tower which follows a buried cable to guide the swing arm into and out of the field corners. A double hinge connection between the main irrigation boom and the swing arm

A center pivot irrigation machine having a swing arm for irrigating corner areas of a field. The swing arm has a steerable support tower which follows a buried cable to guide the swing arm into and out of the field corners. A double hinge connection between the main irrigation boom and the swing arm includes one hinge joint which accommodates pivoting of the swing arm and another hinge joint which controls the operation of the tower drive motors. A cam switch monitors the steering angle of the swing arm tower and turns the sprinklers of the swing tower on and off in accordance with the steering angle to achieve uniform water application. A secondary set of sprinklers on the main boom is deactivated and the entire machine is slowed when the steering angle indicates that the swing arm is covering a rapidly increasing area.

대표청구항 ▼

In a center pivot irrigation machine having a main boom supported to pivot about one end to cover a generally circular area of a field, an extension boom pivotally coupled with the opposite end of said main boom to irrigate corner areas of the field beyond said circular area, means for pivotally ext

In a center pivot irrigation machine having a main boom supported to pivot about one end to cover a generally circular area of a field, an extension boom pivotally coupled with the opposite end of said main boom to irrigate corner areas of the field beyond said circular area, means for pivotally extending the extension boom into corner areas of the field approached by the main boom and pivotally retracting the extension boom out of the corner areas as the main boom departs therefrom, and drive means for propelling the main and extension boom through the field, the improvement comprising: first and second sets of sprinklers each including a plurality of normally activated sprinklers spaced along substantially the entire length of the main boom, each sprinkler in said first and second sets being operable when activated to discharge water from the main boom for application to said circular area of the field; a plurality of sprinklers spaced along the extension boom, each sprinkler on the extension boom being operable when activated to discharge water from the extension boom for application to the corner areas of the field; means for activating the sprinklers on the extension boom in a preselected sequence as the extension boom is being extended into the corner areas of the field; means for deactivating the sprinklers on the extension boom in a preselected sequence as the extension boom is being retracted out of the corner areas of the field; and means for deactivating all of the sprinklers in said first set of sprinklers on the main boom when a preselected sprinkler on the extension boom is activated.