The subject of the invention is a forestry machine in the form of a cantilever multi blade circular saw, designated for trimming tree branches near communication routes, in forests, near power lines etc.

Machines of this type are commonly used as equipment for front loaders of agricultural tractors, front loaders, excavators, and telescopic loaders. Such saws, typically equipped with three or four cutting discs are used for pruning tree branches, for cutting trees of small diameter, for example small roadside trees and for trimming tops and sides of roadside bushes to create hedges.

A multi-disc saw for longitudinal cutting of short sections of logs is known from the patent description PL159952. It has a set of circular saws mounted on a common horizontal shaft and roller guides for the rubbed material. The circular saw set is mounted on a common horizontal shaft supported at the ends and in the center on three self-aligning bearings mounted on a frame.

A circular saw for cutting branches is known from the publication of the Polish description of the utility model W.119037 consisting of such elements as a cover, housing, main frame, mounting bracket, cutting set, angular gear, shaft, claw coupling and hydraulic motor. The cutting unit in the form of two, three or four discs is driven from a hydraulic motor through a shaft and angular gear.

A problem with commonly known solutions is the need to use external power sources from the machines to which the saw is attached such as agricultural tractors, front loaders, excavators, or telescopic loaders. Power from the external sources is provided by a hydraulic drive. Unfortunately, such a solution requires that the powering machine is factory-adapted to work with this type of device, because it has to be equipped with an efficient hydraulic pump, high-flow hydraulic system and an additional oil cooler so that the work could be carried out continuously. Additionally, the known solutions of multi-blade saws mounted on the booms do not have their own control, allowing the steering of the actuators by the operator, directly from the machine control panel.

The subject of the invention is a forestry machine in the form of a cantilever multi blade circular saw, equipped with a frame and a cutting head with cutting discs, mounted on an extendable boom. The essence of the invention is in that the frame is connected with the motor base by the articulated joint of the motor base and the positioning actuator of the motor, and to the motor base the motor and the fuel tank are mounted, and a locking pin is mounted in the motor base of the motor, which enables locking the position of the motor base. The motor has the motor shaft which by means of the first claw clutch is connected with the centrifugal clutch while sequentially a belt transmission articulated telescopic shaft, angulargear, second claw clutch and input shaft are installed in the machine drive system, all of which constitute an independent drive unit of the cutting head. The belt transmission is built from the first pulley mounted on the output shaft and the second pulley, connected to each other through an endless connector in the form of V-belt. The second pulley is connected to the articulated-telescopic shaft, through a connecting shaft rotatably mounted on bearings, while the other end of the articulated-telescopic shaft is connected to the angular gear connected through the second claw clutch with the input shaft passing axially through the articulated head joint to the interior of the cutting head.

Preferably, the belt transmission is covered with an electrically insulating cover of the drive system, which is screwed to the side of the frame, whereby the entire drive system with the cover is shielded with a side electrically insulating cover fastened to the side edges of the frame.

Preferably, on the front and sides of the frame LED work lights are installed, to illuminate the deforestation site. Preferably, the control of the functions of the hydraulic actuators is carried out through the hydraulic distributor flow divider, which it is equipped with levers, the appropriate setting of which changes the position the cutting head, the extension boom, and the motor base.

The advantage of the circular saw according to the invention is the possibility of working the of saw without the need to use an additional external power source. Moreover, thanks to the control panel which the machine is equipped with, the operator can move the saw sideways. In addition, the movable arm of the cutting head allows to work at different angles, speeding up and improving the works connected with trimming of trees or shrubs.

The subject matter of the invention is shown in the embodiments on drawing , in which fig. 1 shows a forestry machine in a front view in an axonometric view with the cutting head in a horizontal position for trimming of hedges, fig. 2 - the machine in a rear view in an axonometric view from with the cutting head in the vertical position for trimming tree branches, Fig. 3 - a cross-section of the centrifugal clutch used, and Fig. 4 - an axonometric view of the machine drive unit.

The forestry machine has an openwork frame 1 to which the main boom 2 is attached, which has the form of a section, in which the extension boom 3 is slidably mounted on the slide bearing 13. The extension boom 3 is movably connected by a joint 12 with the cutting head 11. From the bottom to the frame 1, by means of the articulated joint of the motor base 21 and the positioning actuator of the motor 18, the motor base 20 is attached, to which the motor 4 with the fuel tank 19 are attached. The locking pin 22 is mounted in the motor base 20, which enables the locking of the motor base 20 permanently in different positions, which protects against accidental tilting of the motor 4 and the fuel tank 19. This solution allows the proper leveling of the motor 4 and the fuel tank 19, regardless of the angle of inclination of the frame 1 and the cutting head 11. The motor 4 is covered by the motor cover 24, attached to frame 1. This allows the saw to work at different angles while the motor 4 remains level as shown in Fig. 2.

The motor 4 has a motor shaft 4.1, and the motor shaft 4.1 is connected to the centrifugal clutch 6 by means of a first claw clutch 5. Sequentially, one after another, in the drive system of the machine after the centrifugal clutch 6, there are belt transmission 7, articulated telescopic shaft 8, angular gear 9, second claw clutch 10 and input shaft 11.2, which elements constitute an independent drive unit of the cutting head 11. Belt transmission 7 consists of the first pulley 7.1 mounted on the output shaft 6.2 and a second pulley 7.3 connected with each other through an endless connector in the form of a V-belt 7.2. The second pulley 7.3 is connected to the articulated telescopic shaft 8 through a connecting shaft rotatably mounted on bearings, while the other end of the articulated telescopic shaft 8 is connected to the angular gear 9, connected through the second claw clutch 10 to the input shaft 11.2, whereby the input shaft 11.2 passes axially through the articulated head joint 12 into the interior of the cutting head 11. The belt transmission 7 is covered with an electrically insulating cover 26 of the drive system screwed to the side of the frame 1. The entire drive system with the cover 26 is shielded with a side electrically insulating cover 25 attached to the side edges of the frame 1, as shown in Fig. 1. The covers 25, 26 are made of electrically insulating material in order to increase the safety of cutting work in the vicinity of power lines, as they are the most protruding parts of the machine.

The cutting head 11 has a body 11.1 that functions as a frame and housing for gear trains and protects the internal parts of the head 11 from damage. The input shaft 11.2 axially passes through the articulated head joint 12, which cooperates through the bevel gears 11.5 with the distribution shaft 11.3. The distribution shaft 11.3, through the bevel gears 11.5 cooperates with the output shaft 11.4, which drives the cutting discs 11.8, which are mounted in hub 11.7 with bearings. Teeth 11.9 are attached to the body 11.1 between the cutting discs 11.8 facilitating the branches cutting. Additionally, the cutting discs 11.8 are partially covered by the saw shield 23, which is attached to the body of the head 11.1.

Inside the main boom 2, a sliding movable extension boom 3 is mounted. The extension cycle is carried out by the boom actuator 16 attached with one end to the main boom 2, and with the other end to the extension boom 3. The boom actuator 16 of the boom 3 is located inside the main boom 2 and inside the extending boom 3, while the external mounting of the boom actuator 16 is covered with the side insulating cover 25.

By means of the actuator of the head 17, which is fixed with one end centrally to the body 11.1 of the cutting head 11 and with the other end to the lug of the extension arm 3, the angle of inclination of the cutting head 11 is changed.

The functions of hydraulic cylinders are controlled by flow divider 15, which is equipped levers and appropriate levers setting changes the position of the cutting head 11, extension boom 3 and the motor base 20.

On the sides and from the front to the frame 1, in the motor cover 24, LED work lights 14 which illuminate a deforestation site are installed.

The centrifugal clutch 6 (fig. 3) cooperates with the motor 4. The shaft 4.1 of the motor 4 is mounted in a first claw clutch 5, in which, on the other side, the input shaft 6.5 of the clutch 6 is mounted axially to the shaft 4.1 of the motor 4. The input shaft 6.5 is mounted in the first bearing 6.6, the second bearing 6.7, and then in the third bearing 6.8. The first bearing 6.6 is screwed from the outside of one of the side walls of the frame 1, the second bearing 6.7 is seated in the drum cover 6.3, while the third bearing 6.8 is seated in the clutch drum 6.1. Between the second bearing 6.7 and the third bearing 6.8, the clutch jaws 6.4 are installed on the shaft 6.5, which expand due to the rotation of the input shaft 6.5. The gradual expansion of the clutch jaws 6.4 causes friction on the inner surface of the clutch drum 6.1 causing it to rotate. The clutch drum 6.1 ends with the output shaft 6.2, embedded in the fourth bearing, which is installed form the outer side of the second side wall of the frame 1. At the end of the output shaft 6.2 the centrifugal clutch 6 is fastened to the first pulley 7.1.