The present invention relates to a safety device of a harrow for a tractor. The purpose of the present invention is to provide the safety device of the harrow for the tractor preventing damage to a locking bar by absorbing an initial outer force applied to the locking bar when an outer harrow plate rotates in a direction opposite to a direction where the outer force is generated by obstacles such as stones or a clod. To achieve the purpose, the present invention, the safety device of the harrow for the tractor installed on the rear side of the tractor and the outer harrow plate, is connected to both sides of a central harrow plate includes a harrow fixating unit mounted between the central harrow plate and the outer harrow plate and enabling the outer harrow plate to rotate in the front and rear sides of the central harrow plate the locking bar installed to enable the body to rotate in the rear side of the outer harrow plate and of which rotation to the front side is limited and the lower part is projected toward the outer side of the underside of the outer harrow plate or central harrow plate and an elastic locking unit installed on the central harrow plate and locking the lower part of the rear side of the locking bar to elastically supporting the movement of the outer harrow plate to the rear side while limiting the movement. The elastic locking unit is characterized by being fixated to the central harrow plate and being compose of a housing with an insertion hole on the front side a bolt inserted inside the housing via the insertion hole of the housing and of which a head unit exposed to the outside is toward the locking bar and a spring installed inside the housing and elastically supporting the bolt.COPYRIGHT KIPO 2015본 발명은 트랙터용 써레의 안전장치에 관한 것으로, 돌이나 흙덩어리 등의 장애물에 의해 외측 써레판이 외력이 발생하는 반대방향으로 회전할 때 걸림바에 가해지는 초기의 외력을 흡수함으로써 걸림바의 손상을 방지하도록 한 트랙터용 써레의 안전장치를 제공하는데 그 목적이 있다.상기의 목적을 달성하기 위하여 본 발명은, 트랙터의 후방에 설치되면서 중앙 써레판의 양측에 외측 써레판이 연결되며, 된 트랙터용 써레에 있어서, 상기 중앙 써레판과 외측
