What is the principle of the kneeling mower?
The lawnmower or pruner rotates the rotary motion of the motor into a left and right swing of the blade by means of an eccentric
Reciprocating lawn mower, never heard of. Hob cutter, turntable lawn mower, nylon rope lawn mower, lawn mower, pruning shears. What you might say is a lawn mower or a pruner
Or swing back and forth, so as to cut the object of the tool.
