Airborne tree trimming apparatus

Airborne tree trimming apparatus for installation on a helicopter or the like and cutting woody growth beneath the helicopter along the flight path of the helicopter, said apparatus comprising a boom extension having one end attached to said helicopter substantially at the center of lift of the helicopter, said boom extension being restrained from substantial rotation about the longitudinal axis thereof;

• a boom pivot provided on the opposite end of said boom extension;
• an operating boom extending from said boom pivot in substantially coplanar pivoting relationship with respect to said boom extension;
• a plurality of circular saw blades mounted in tandem on said operating boom for rotation substantially in a common plane, said circular saw blades oriented in close proximity to each other;
• an internal combustion engine fixedly carried by said operating boom between said boom pivot and said circular saw blades;
• and power transmission means connecting said internal combustion engine to said circular saw blades, for rotating said circular saw blades in concert and cutting the woody growth responsive to airborne operation of the helicopter and said internal combustion engine.

Airborne helicopter-mounted tree trimming apparatus for cutting trees and woody growth at selected altitudes, said apparatus comprising boom mounting structure attached to the underside of the helicopter near the center of lift thereof;

• a boom extension having one end pivotally mounted to said boom mounting structure about a pivot axis which is horizontal and transverse to the principal direction of flight of said helicopter, said boom extension being restrained from substantial rotation about its longitudinal axis;
• an operating boom having one end hingedly carried by the opposite end of said boom extension, said operating boom pivotable with respect to said boom extension in a plane which extends substantially through the longitudinal axis of the helicopter;
• a plurality of circular saw blades mounted on said operating boom for rotation about companion axes which are substantially parallel to said pivot axis, respectively, said circular saw blades arranged substantially in a common plane in spaced, tandem relationship;
• an internal combustion engine mounted on said operating boom between said opposite end of said boom extension and said circular saw blades;
• and flexible power transmission means connecting said circular saw blades and said internal combustion engine in driving relationship, whereby said circular saw blades engage and cut the woody growth beneath the helicopter along a flight path at the selected altitudes responsive to operation of said internal combustion engine.

Airborne helicopter-mounted tree trimming apparatus for use with a helicopter having a selected cargo lift capacity, said apparatus comprising boom mounting structure attached to the underside of said helicopter near the center of lift thereof:

• a first boom pivotally mounted to said boom mounting structure about a pivot axis which is horizontal and transverse to the principal direction of flight of said helicopter, said first boom being restrained from substantial rotation about its longitudinal axis:
• a second boom hingedly connected to the lower end of said first boom;
• a plurality of circular saw blades rotatably mounted in tandem relationship on said second boom for rotation about axes which are parallel to said pivot axis, said circular saw blades oriented substantially in a common plane;
• an internal combustion engine carried by said second boom;
• and power transmission means connecting said internal combustion engine to said circular saw blades for rotating said circular saw blades at a selected speed responsive to operation of said internal combustion engine.