Coupling hook for a three-point connection on a tractor

Abstract

A coupling hook for lockingly engaging a coupling pin on an implement or the like has a pocket having a slot in which a pivot element is slidably received and an operating lever is pivotally mounted to the pivot element. A latch is pivotally connected to the operating lever and has one end extending through a passage toward the hook opening. The latch is pivotable and slidable upon a supporting or guiding pin such that when a coupling pin acts upon an unlocking surface on the nose-portion of the latch during a coupling operation, the latch will slide back into the pocket to permit the coupling pin to be received within the hook opening. When the coupling pin is locked within the hook opening, the pin will bear against a locking surface on the nose-portion of the latch to urge the supporting surface of the latch against an edge of the passage through which the latch extends so that a moment is produced acting upon the latch and operating lever to urge the latch into the hook opening. The slot has a recess at one end thereof to receive the pivot element when the operating lever is pivoted in the unlocking direction beyond a predetermined angle such that the pivot element and thus the latch will be retained in an unlocked position until an extension on the operating lever is manually actuated to release the latch.