Tree trimming and pruning machine

A tree-trimming and pruning machine comprising:

• a first plurality of rotary cutter blades are staggered in line on a first cutter bar,
• a second plurality of rotary cutter blades are staggered in line on a second cutter bar,
• a base end of the first cutter bar that is attached pivotally to a first side of an operative end of a hydraulically operative lifting means positioned on a vehicle,
• a base end of the second cutter bar being attached pivotally to a second side of the operative end of the hydraulically operative lifting means positioned on the vehicle,
• the operative end of the hydraulically operative lifting means is pivotal on an operative-end axle that is perpendicular to a lifting plane of the hydraulically operative lifting means,
• a first lateral hydraulic actuator in pivot-causing relationship laterally between the first cutter bar and the first side of the operative end of the hydraulically operative lifting means,
• a second lateral hydraulic actuator in pivot-causing relationship laterally between the second cutter bar and the second side of the operative end of the hydraulically operative lifting means,
• an operative-end hydraulic actuator in pivot-causing relationship linearly between the operative end of the hydraulically operative lifting means and the hydraulically operative lifting means to which its operative end is attached pivotally,
• a first plurality of hydraulic motors having motor shafts to which the first plurality of rotary cutter blades are attached respectively one-to-one,
• a second plurality of hydraulic motors having motor shafts to which the second plurality of rotary cutter blades are attached respectively one-to-one,
• a first hydraulic-motor line in fluid communication from a source of pressurized hydraulic fluid for the first plurality of hydraulic motors which are positioned in line consecutively on the first cutter bar,
• the first hydraulic-motor line being connected in a series extending from a first hydraulic motor to a last hydraulic motor of the first plurality of hydraulic motors,
• a first plurality of relief lines having first ends of the first plurality of relief lines connected to the first hydraulic-motor line and terminal ends of the first plurality of relief lines connected to a hydraulic header,
• the first plurality of relief lines being in fluid communication between the first hydraulic-motor line and the hydraulic header at positions in the first hydraulic-motor line that are intermediate adjacent hydraulic motors of the first plurality of hydraulic motors,
• a first plurality of one-way check valves comprised of a one-way check valve proximate each of the first plurality of relief lines intermediate the first hydraulic-motor line and the hydraulic header,
• a second hydraulic-motor line in fluid communication from a source of hydraulic fluid to the second plurality of hydraulic motors which are positioned in line consecutively on the second cutter bar,
• the second hydraulic-motor line being connected in a series extending from a first hydraulic motor to a last hydraulic motor of the second plurality of hydraulic motors,
• a second plurality of relief lines having first ends of the second plurality of relief lines connected to the second hydraulic-motor line and terminal ends of the second plurality of relief lines connected to the hydraulic header that is fluidly intermediate hydraulic pumps and a hydraulic-fluid reservoir,
• the second plurality of relief lines being in fluid communication between the second hydraulic-motor line and the hydraulic header at positions in the second hydraulic-motor line that are intermediate adjacent hydraulic motors of the second plurality of hydraulic motors,
• a second plurality of one-way check valves comprised of a one-way check valve proximate each of the second plurality of relief lines intermediate the second hydraulic-motor line and the hydraulic header,
• a pressure-relief valve fluidly intermediate the hydraulic header and the hydraulic-fluid reservoir, and
• the first plurality of one-way check valves, the second plurality of one
• way check valves and the pressure-relief valve being structured to allow flow of hydraulic fluid from the first hydraulic motor line and from the second hydraulic-motor line to the hydraulic header and to the hydraulic-fluid reservoir designedly when any of the first plurality of hydraulic motors or of the second plurality of hydraulic motors are deterred in speed of rotation due to various cutting conditions, such that temporarily high levels of rotational resistance to any one or plurality of the rotary cutter blades do not cause buildup of damaging levels of pressure from rotational momentum of upstream hydraulic motors that causes pumping action that exceeds pressure capacity of downstream hydraulic components.