said drive shaft carrying eccentric means to be rotated by the shaft bearing means carried by and within said first tubular part said bearing means receiving said eccentric means to oscillate said first tubular part said head and said blade as said eccentric means is rotated by the shaft and counterbalance means located on said drive shaft to rotate therewith and reduce vibration created by said oscillation application_number US 47369583 A description referring now to the drawings and initially to fig1 and 2 inclusive for this purpose it will be seen that one type of machine in which the invention may be incorporated has been designated in its entirety by reference number 10 mounted on the machine 10 are a pair of rubber tires 12 which permit the machine 10 to be easily transported and maneuvered the wheels 12 are carried by an axle 14 which in turn passes through the rear portions of the base frame 16 mounted on the frame 16 is an electrical motor 18 the machine 10 may alternately be powered by an internal combustion engine the motor 18 is held in place by four mounting bolts 19 which pass through slots 20 in the frame 16 when the bolts 19 are loosened the motor can be moved forward or backward on the frame 16 by reason of the slots 20 to adjust the tension in the drive belt 21 covering the motor 18 and attached to the frame 16 is a cover shroud 22 the shroud 22 slides over the side walls 23 of the frame and is held in place by bolts 24 as can be seen in fig1 positioned.