1. Field of the Invention
The present invention relates to a shearing tool and, more particularly, to a pruning hook for a gardening purpose to shear branches or leaves at a higher location.
2. Description of the Related Art
A conventional pruning hook in accordance with the prior art shown in FIG. 7 comprises an extension shank 60, a blade unit 70 mounted on a front end of the extension shank 30, a driving unit 80 mounted on a rear end of the extension shank 30, an elastic member 83 mounted on the driving unit 80, and a linkage 61 connected between the blade unit 70 and the driving unit 80. The blade unit 70 includes a fixed blade 71 mounted on the front end of the extension shank 60 and a movable blade 72 pivotally connected with and movable relative to the fixed blade 71. The driving unit 80 includes a fixed handle 81 mounted on the rear end of the extension shank 60 and a movable handle 82 pivotally connected with and movable relative to the fixed handle 81. The elastic member 83 is biased between the fixed handle 81 and the movable handle 82.
In operation, when the driving unit 80 is pressed by a user's hand, the driving unit 80 is operated to drive the linkage 61 which drives the blade unit 70 so as to perform a cutting action. On the contrary, when the pressing force applied on the driving unit 80 disappears, the driving unit 80 is driven by the restoring force of the elastic member 83 to open the blade unit 70 so that the blade unit 70 is opened at a normal state by the elastic force of the elastic member 83.
However, the driving unit 80 is driven by a pressing force applied by the user's hand to drive the blade unit 70 so that the blade unit 70 has a smaller shearing force to perform the cutting action and cannot cut a larger object easily. In addition, the user's hand needs to press the driving unit 80 successively so as to drive the blade unit 70, thereby easily causing pain or an uncomfortable sensation to the user. Further, the linkage 61 is connected between the blade unit 70 and the driving unit 80 to directly transmit the force from the driving unit 80 to the blade unit 70, so that the blade unit 70 is not operated in an energy-saving manner.