Patent ID: 11925139
Assignee: nan
Field: Other special machines (Mechanical engineering)
Classification: CPC A | IPC A

Claim 10:
11. A permanent lawn mower for installation in soil, the permanent lawn mower comprising:
one or more cutting heads;
the one or more cutting heads each including a blade that extends up and out of a housing, the blade cutting surrounding grass, the blade then retracting into the housing;
each cutting head of the one or more cutting heads surrounded by the housing when in a retracted position;
the housing includes internal threads;

each cutting head of the one or more cutting heads moving along a cutting head shaft;
rotation of the cutting head shaft causing rotation that creates upward movement along the internal threads of the housing;

a drive unit;
the drive unit rotating the cutting head shaft;
the drive unit causing the one or more cutting heads to extend up and out of the housing;
the drive unit causing the blade to oscillate, creating a cutting action;
the drive unit causing the blade to retract into the housing;

an ascender;
the ascender internally splined to interact with external splines of the cutting head shaft;
the ascender externally threaded to interface with the internal threads of the housing;
rotation of the cutting head shaft causing rotation of the ascender, in turn causing extension or retraction of the one or more cutting heads;

whereby the one or more cutting heads are installed in areas that are difficult to access, thus avoiding use of a mobile lawn mower.