TREE GRAB Russian patent published in 1994 - IPC

FIELD: silvicultural engineering. SUBSTANCE: tree grab comprises bearing member 1 connected to hoisting mechanism. Jaw 2 articulated on one end of said bearing member has cutting edge 4 in its lower part. The other end of bearing member 1 carries articulated jaws 3 provided with projections 5. Tree grab also comprises two hydraulic power cylinders 6 and jaw synchronizer 7 which has additional jaws 8 articulated at the side of jaw 2. Upper arm of jaws 8 is articulated on axle 9 of jaw 2 with the aid of bearing member 1 while housing of hydraulic cylinders 6 is articulated on upper arm of jaw 2. One of additional jaws 8 and jaw 2 are interconnected by torsion spring 10 mounted on their common axle 11. Jaw 2 and synchronizer 7 provide for complete entry of cutter 4 between synchronizer sideplates with the jaws in closed position. Torsion spring 10 keeps jaw 2 against closing before jaws 8 when the latter are not loaded with grabbed material. First the material shall be grabbed by jaws 3 and 8, then cut by jaw 2. EFFECT: improved design. 5 dwg