Tree shaker comprises a construction, which have a front end engaging two arms for gripping a tree. It consists of two shafts. A first shaft having a first weight is rotatably engaged by the construction and is rotated by a first motor a first weight connected to or integrally formed with the first shaft and a second shaft having a second weight is rotatably engaged by the construction and is rotated by a second motor. The first and second shafts being coaxial such that one of them is internally located relative to the other and a stopping mechanism is connected to one of the weights for restricting the relative orientation of the weights to a maximum of 180.degree. one relative to the other & to a minimum of a close contact between one another.