CA2242625A1 - Lightweight felling head - Google Patents
Lightweight felling head Download PDFInfo
- Publication number
- CA2242625A1 CA2242625A1 CA 2242625 CA2242625A CA2242625A1 CA 2242625 A1 CA2242625 A1 CA 2242625A1 CA 2242625 CA2242625 CA 2242625 CA 2242625 A CA2242625 A CA 2242625A CA 2242625 A1 CA2242625 A1 CA 2242625A1
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- Prior art keywords
- felling head
- frame
- motor
- recited
- gearbox
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- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G23/00—Forestry
- A01G23/02—Transplanting, uprooting, felling or delimbing trees
- A01G23/08—Felling trees
- A01G23/081—Feller-bunchers, i.e. with bunching by felling head
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- Life Sciences & Earth Sciences (AREA)
- Biodiversity & Conservation Biology (AREA)
- Ecology (AREA)
- Forests & Forestry (AREA)
- Environmental Sciences (AREA)
- Retarders (AREA)
Abstract
Described herein is a lightweight felling head for restraining, cutting and manipulating trees. The felling head comprises a holder that is connected to the manipulator arm, or crane, of the logging vehicle. At least partially housed in the holder is a motor capable of imparting rotational motion to a frame, the frame being preferably disposed with restraining arms for gripping trees as well as a saw blade for cutting trees. The felling head also comprises a bearing-like member to rotatably connect the frame to the holder. Preferably, the felling head further comprises a gearbox for augmenting the torque produced by the motor.
The gearbox, which is preferably of planetary type, is at least partially housed in the frame of the felling head.
Since the motor is mounted on the holder, the weight, size and complexity of the frame are reduced.
The gearbox, which is preferably of planetary type, is at least partially housed in the frame of the felling head.
Since the motor is mounted on the holder, the weight, size and complexity of the frame are reduced.
Description
Lightweight Felling Head Field of the Invention The present invention relates to logging machinery and, more particularly, to an improved felling head for gripping, cutting and manipulating trees.
Background of the Invention For many years now, felling heads have replaced the traditional chainsaw in most logging operations where trees are of medium diameter. The felling head is usually used to restrain, cut, accumulate and pile trees in a single, quick operation. The felling head is normally mounted on the end of a hydraulic crane or manipulator, which is, in turn, mounted to a tractor or tracked vehicle. The felling head is a much more efficient device than the traditional hand-carried chainsaw and, surprisingly, it causes less damage to the environment because felled trees are not dragged on the forest floor, crushing and uprooting young stems, saplings and undergrowth.
Some felling heads are especially well-suited for manipulating trees mainly because they can be tilted back and forth as well as sideways. In this specification, the expression "tilted back and forth" refers to the pitch of the frame as illustrated in Figure 1.
Similarly, the expressions "tilted sideways" or "side tilt" should be construed to refer to the roll of the frame about the axis of rotation of the drive shaft of the motor as illustrated in Figure fi.
The back and forth tilting motion is achieved by a hydraulic actuator normally installed on the manipulator arm (or crane). The double attachment of the felling head to the manipulator arm allows the felling head to pivot about one of the attachment points while the hydraulic actuator pushes or pulls on the other attachment point. This back and forth tilt (or pitch) makes it possible for the felling head to position itself parallel to the tree and, after the cut, to lay the tree on the ground.
In addition to the back and forth pitch, the sideways tilting motion (i.e. the roll) gives the felling head greater maneuverability in gripping, cutting and manipulating trees and thus increases the potential for producing larger piles of trees in a given period of time without having to constantly readjust the position of the tractor. Thus, a highly maneuverable felling head increases the efficiency of the logging operation. Furthermore, since the felled trees can be easily manipulated and piled in a convenient location for the transporter to pick them up, the harvesting minimizes the damage to neighboring trees and saplings.
Although the present description deals primarily with the gripping, cutting and manipulating of trees, it should be appreciated by a man skilled in the art that the felling head of the present invention could also be used to grip, cut and manipulate wooden poles (e.g.
telephone poles or power-line poles) or, with a different type of saw blade practically any tree-like or pole-like object.
In the prior art, many different types of mechanisms have been used to create the side tilting motion of the felling head. Some prior art systems use a pair of hydraulic actuators mounted on the felling head that are linked to a large gear, itself linked to a central gear around which the tilting motion is achieved. The hydraulic actuators push and pull simultaneously on the large gear, thereby rotating the felling head around the central gear. In this case, the rotation is limited by the travel of the hydraulic actuators to a side tilt rotation of about 180 degrees.
Other systems use a hydraulic motor and chain arrangement. A hydraulic motor with a drive shaft and sprocket is mounted on the felling head and linked with a chain to a large central sprocket located at the rotational axis of the felling head. When the motor sprocket turns, it induces a side tilting motion to the felling head. This arrangement has a much larger rotational range than the hydraulic actuator arrangement described in the previous paragraph. Its range can reach 360 degrees.
Other combinations of actuators, gears and chains are commonly found in the prior art but they all share the same feature in that the components necessary for the side-tilt rotation are housed directly on the felling head itself. This contributes extra weight and inertia to the felling head which, in turn, reduces the maneuverability of the felling head. Not only are such cumbersome felling heads slower to rotate but the energy expenditure during operation is higher.
Moreover, since the motor is located on the frame, the hydraulic lines have to be routed from the holder to the frame. When operating amid thick branches, these hydraulic lines may become snagged.
Thus, there is a need in the logging industry for an improved felling head.
Objects and Statement of the Invention It is therefore an object of the present invention to provide a felling head that is light and thus is more easily maneuvered.
It is another object of the present invention to provide a felling head that is compact.
It is another object of the present invention to provide a felling head that is mechanically reliable and requires very little mainl:enance.
It is another object of the present invention to provide a felling head that has few moving or exposed parts.
It is another object of the present invention to provide a felling head that is less susceptible to damage.
It is another object of the present invention to provide a felling head that has few components and is thus easy and inexpensive to manufacture.
As embodied and broadly described herein, the present invention provides a felling head for restraining, cutting and manipulating trees, the felling head comprising a holder for connection to a manipulator arm, a motor mounted on the holder, the motor being adapted to impart rotational motion to a frame, and a bearing-like member to rotatably connect the frame to the holder. Without the additional weight of the motor, the frame is lighter. Since the frame is lighter, the frame is more maneuverable and can achieve higher angular accelerations for a given motor torque rating. Moreover, since the frame is lighter, not only is the frame more maneuverable but the amount of energy dissipated during operation is less than the energy dissipated had the motor been located on the frame. Furthermore, the presence of the motor on the holder simplifies the hydraulic routing to the motor which thus leaves the frame unencumbered by hydraulic lines. When operating amid thick branches, a felling head without hydraulic lines running from the manipulator arm to the frame is less likely to become ensnared or tangled.
Advantageously, the motor has a drive shaft defining a rotational axis about which the frame is rotatably mounted. Such a felling head would be more compact and thus more easily operated in tight spaces. Furthermore, having the motor coaxial with the axis of rotation of the frame simplifies the transmission of torque from the motor to the frame. In other words, all that is required to transmit torque from the drive shaft of the motor to the frame is a gearbox. The simplicity of this axial configuration of the motor not only simplifies design and assembly, but it also reduces the number of parts required to implement the design and thus reduces the cost of each felling head.
Advantageously, the holder defines a cavity in which the motor is at least partially housed, the drive shaft protruding from the cavity. Thus, the holder protects the motor from collisions with trees and branches and likewise protects the motor from dirt, dust and other deleterious elements of the environment.
Advantageously, the felling head further comprises a gearbox, the gearbox being preferably of planetary type. The use of a planetary gearbox ensures that a very large gear ratio is obtained between the drive shaft of the motor and the frame. In other words, a planetary gearbox can greatly augment the torque produced by the drive shaft of the motor. While the torque necessary to rotate the frame is large, the torque required to rotate the frame when gripping a multitude of tall trees can become enormous. Thus, a planetary gearbox is needed to increase the torque output by the drive shaft of the motor to a level sufficient to rotate and manipulate both the frame and the frame's load of trees.
Advantageously, the frame defines a cavity in which the gearbox is at least partially housed, the gearbox being adapted to cooperate with the drive shaft. Thus, the frame protects the gearbox from collisions with trees, branches, and likewise protects the gearbox from dirt, dust and other deleterious elements of the environment.
Advantageously, the motor is radially spaced apart from the axis of rotation defined by the bearing-like member. In this configuration, the motor is mounted to the holder but the drive shaft of the motor is not coaxial with the axis of rotation of the frame. The motor is linked to the frame via a transmission involving either a pulling belt, a chain and sprocket, or a rack and pinion or a gearbox. In this configuration, with the gearbox not mounted to the frame, the frame would be even lighter and more maneuverable.
Other objects and features of the invention will become apparent by reference to the following description and drawings.
Brief Description of the Drawings A detailed description of the preferred embodiments of the present invention is provided hereinbelow, by way of example only, with reference to the accompanying drawings, in which:
Figure 1 is a side elevational view of the felling head mounted on the crane (or manipulator) in the logging environment.
Figure 2 is a side elevational view of the felling head restraining a tree.
Figure 3 is a rear elevational view of the felling head showing the details of the holder.
Figure 4 is a side elevational view of the motor and gearbox arrangement.
Background of the Invention For many years now, felling heads have replaced the traditional chainsaw in most logging operations where trees are of medium diameter. The felling head is usually used to restrain, cut, accumulate and pile trees in a single, quick operation. The felling head is normally mounted on the end of a hydraulic crane or manipulator, which is, in turn, mounted to a tractor or tracked vehicle. The felling head is a much more efficient device than the traditional hand-carried chainsaw and, surprisingly, it causes less damage to the environment because felled trees are not dragged on the forest floor, crushing and uprooting young stems, saplings and undergrowth.
Some felling heads are especially well-suited for manipulating trees mainly because they can be tilted back and forth as well as sideways. In this specification, the expression "tilted back and forth" refers to the pitch of the frame as illustrated in Figure 1.
Similarly, the expressions "tilted sideways" or "side tilt" should be construed to refer to the roll of the frame about the axis of rotation of the drive shaft of the motor as illustrated in Figure fi.
The back and forth tilting motion is achieved by a hydraulic actuator normally installed on the manipulator arm (or crane). The double attachment of the felling head to the manipulator arm allows the felling head to pivot about one of the attachment points while the hydraulic actuator pushes or pulls on the other attachment point. This back and forth tilt (or pitch) makes it possible for the felling head to position itself parallel to the tree and, after the cut, to lay the tree on the ground.
In addition to the back and forth pitch, the sideways tilting motion (i.e. the roll) gives the felling head greater maneuverability in gripping, cutting and manipulating trees and thus increases the potential for producing larger piles of trees in a given period of time without having to constantly readjust the position of the tractor. Thus, a highly maneuverable felling head increases the efficiency of the logging operation. Furthermore, since the felled trees can be easily manipulated and piled in a convenient location for the transporter to pick them up, the harvesting minimizes the damage to neighboring trees and saplings.
Although the present description deals primarily with the gripping, cutting and manipulating of trees, it should be appreciated by a man skilled in the art that the felling head of the present invention could also be used to grip, cut and manipulate wooden poles (e.g.
telephone poles or power-line poles) or, with a different type of saw blade practically any tree-like or pole-like object.
In the prior art, many different types of mechanisms have been used to create the side tilting motion of the felling head. Some prior art systems use a pair of hydraulic actuators mounted on the felling head that are linked to a large gear, itself linked to a central gear around which the tilting motion is achieved. The hydraulic actuators push and pull simultaneously on the large gear, thereby rotating the felling head around the central gear. In this case, the rotation is limited by the travel of the hydraulic actuators to a side tilt rotation of about 180 degrees.
Other systems use a hydraulic motor and chain arrangement. A hydraulic motor with a drive shaft and sprocket is mounted on the felling head and linked with a chain to a large central sprocket located at the rotational axis of the felling head. When the motor sprocket turns, it induces a side tilting motion to the felling head. This arrangement has a much larger rotational range than the hydraulic actuator arrangement described in the previous paragraph. Its range can reach 360 degrees.
Other combinations of actuators, gears and chains are commonly found in the prior art but they all share the same feature in that the components necessary for the side-tilt rotation are housed directly on the felling head itself. This contributes extra weight and inertia to the felling head which, in turn, reduces the maneuverability of the felling head. Not only are such cumbersome felling heads slower to rotate but the energy expenditure during operation is higher.
Moreover, since the motor is located on the frame, the hydraulic lines have to be routed from the holder to the frame. When operating amid thick branches, these hydraulic lines may become snagged.
Thus, there is a need in the logging industry for an improved felling head.
Objects and Statement of the Invention It is therefore an object of the present invention to provide a felling head that is light and thus is more easily maneuvered.
It is another object of the present invention to provide a felling head that is compact.
It is another object of the present invention to provide a felling head that is mechanically reliable and requires very little mainl:enance.
It is another object of the present invention to provide a felling head that has few moving or exposed parts.
It is another object of the present invention to provide a felling head that is less susceptible to damage.
It is another object of the present invention to provide a felling head that has few components and is thus easy and inexpensive to manufacture.
As embodied and broadly described herein, the present invention provides a felling head for restraining, cutting and manipulating trees, the felling head comprising a holder for connection to a manipulator arm, a motor mounted on the holder, the motor being adapted to impart rotational motion to a frame, and a bearing-like member to rotatably connect the frame to the holder. Without the additional weight of the motor, the frame is lighter. Since the frame is lighter, the frame is more maneuverable and can achieve higher angular accelerations for a given motor torque rating. Moreover, since the frame is lighter, not only is the frame more maneuverable but the amount of energy dissipated during operation is less than the energy dissipated had the motor been located on the frame. Furthermore, the presence of the motor on the holder simplifies the hydraulic routing to the motor which thus leaves the frame unencumbered by hydraulic lines. When operating amid thick branches, a felling head without hydraulic lines running from the manipulator arm to the frame is less likely to become ensnared or tangled.
Advantageously, the motor has a drive shaft defining a rotational axis about which the frame is rotatably mounted. Such a felling head would be more compact and thus more easily operated in tight spaces. Furthermore, having the motor coaxial with the axis of rotation of the frame simplifies the transmission of torque from the motor to the frame. In other words, all that is required to transmit torque from the drive shaft of the motor to the frame is a gearbox. The simplicity of this axial configuration of the motor not only simplifies design and assembly, but it also reduces the number of parts required to implement the design and thus reduces the cost of each felling head.
Advantageously, the holder defines a cavity in which the motor is at least partially housed, the drive shaft protruding from the cavity. Thus, the holder protects the motor from collisions with trees and branches and likewise protects the motor from dirt, dust and other deleterious elements of the environment.
Advantageously, the felling head further comprises a gearbox, the gearbox being preferably of planetary type. The use of a planetary gearbox ensures that a very large gear ratio is obtained between the drive shaft of the motor and the frame. In other words, a planetary gearbox can greatly augment the torque produced by the drive shaft of the motor. While the torque necessary to rotate the frame is large, the torque required to rotate the frame when gripping a multitude of tall trees can become enormous. Thus, a planetary gearbox is needed to increase the torque output by the drive shaft of the motor to a level sufficient to rotate and manipulate both the frame and the frame's load of trees.
Advantageously, the frame defines a cavity in which the gearbox is at least partially housed, the gearbox being adapted to cooperate with the drive shaft. Thus, the frame protects the gearbox from collisions with trees, branches, and likewise protects the gearbox from dirt, dust and other deleterious elements of the environment.
Advantageously, the motor is radially spaced apart from the axis of rotation defined by the bearing-like member. In this configuration, the motor is mounted to the holder but the drive shaft of the motor is not coaxial with the axis of rotation of the frame. The motor is linked to the frame via a transmission involving either a pulling belt, a chain and sprocket, or a rack and pinion or a gearbox. In this configuration, with the gearbox not mounted to the frame, the frame would be even lighter and more maneuverable.
Other objects and features of the invention will become apparent by reference to the following description and drawings.
Brief Description of the Drawings A detailed description of the preferred embodiments of the present invention is provided hereinbelow, by way of example only, with reference to the accompanying drawings, in which:
Figure 1 is a side elevational view of the felling head mounted on the crane (or manipulator) in the logging environment.
Figure 2 is a side elevational view of the felling head restraining a tree.
Figure 3 is a rear elevational view of the felling head showing the details of the holder.
Figure 4 is a side elevational view of the motor and gearbox arrangement.
Figure 5 is a rear elevational view of the gearbox showing the planetary gear arrangement.
Figure 6 is a rear elevational view of the felling head rotating sideways.
Figure 7 is a side elevational view of the motor and bearing-like member arrangement.
Figure 8 is a side elevational view of a motor and gearbox arrangement wherein the motor is not located coaxially with the axis of rotation of the felling head.
Figure 9 is a front elevational view of the motor and gearbox arrangement of Figure 8.
Figure 10 is a top view of the path of the tractor in a logging area and an example of an environmentally-conscious tree piling pattern.
In the drawings, preferred embodiments of the invention are illustrated by way of examples. It is to be expressly understood that the description and drawings are only for the purpose of illustration and are an aid for understanding. They are not intended to be a definition of the limits of the invention.
Description of the Preferred Embodiments Figures 1 and 2 illustrate a first embodiment of a felling head according to the present invention designated comprehensively by the reference numeral 10. The felling head 10 is mounted to a tilting holder 30 which in turn is normally attached to a manipulator arm 5 of a tractor 4 or other such vehicle. The felling head 10 is made of a frame 20 on which is typically mounted a plurality of restraining arms 15 used to restrain the trees as the saw blade located normally at the base 21 of the frame 20 cuts the bottom part of the tree trunk. The frame 20 is provided with a transmission arrangement, for example a gearbox 50. In the illustrated example, the gearbox SO is of planetary type. The planetary gearbox 50 is solidly affixed to the tilting holder 30. The tilting holder 30 has a cavity in which a hydraulic motor 40 is at least partially G
housed. The motor 40 is coupled to the gearbox 50 via a drive shaft 45 which transfers the rotary motion of the motor 40 to the gearbox 50. Since the frame 20 is fixed to the outer shell of the gearbox 50, the frame 20 therefore follows the rotation of the gearbox. The frame 20 rotates about the axis of the drive shaft 45. For the purposes of this specification, this arrangement is termed "coaxial" since the axis of rotation of the drive shaft 45 is in alignment with the axis of rotation of the frame 20. Furthermore, this arrangement permits the frame 20 to rotate at least 360 degrees with respect to the holder 30. Thus, the felling head 10 can be maneuvered into practically any posture for gripping, cutting and manipulating trees.
In normal use, the tractor 4 is positioned near a tree 2. The manipulator arm 5 is extended and the frame 20 of the felling head 10 is positioned preferably parallel to the tree trunk.
Depending on the position of the tractor 4 relative to the tree 2, the felling head 10 may need to be tilted backward or forward and/or sideways.
To control the backward and forward motion of the felling head 10, the operator actuates the hydraulic actuator 8. The holder 30 is linked to the manipulator arm 5 by a pivoting point 32 and to the hydraulic actuator 8 at a pivot point 34 of the holder 30. As the hydraulic actuator 8 pulls or pushes at the pivot point 34, the holder 30 and therefore the felling head 10 rotate about the pivoting point 32. If the operator needs to tilt the felling head 10 sideways, he actuates the hydraulic motor 40. The drive shaft 45 of the motor 40 imparts rotary motion to the gearbox 50 and therefore to the felling head 10.
When the felling head 10 is properly aligned with t:he tree 2, the restraining arms 15 open and grasp the tree 2. In that same motion, the saw located at the base 21 of the frame 20 cuts the tree 2. With the tree cut and firmly held by the restraining arms 15 of the felling head 10, the manipulator arm 5 lifts the tree 4, the motor 40 rotates the frame 20 so that the length of the tree is generally parallel to the ground and then, finally, the manipulator arm 5 lays the tree 4 on the ground in a position that will be easily accessible for the collection vehicle to pick up and carry away. To facilitate the pick-up procedure, it is preferable to make neat piles of trees, having every tree parallel to each other. This is why the sideways rotation, or roll, of the felling head 10 is advantageous. Because the felling head 10 is able to tilt sideways, the operator is able to place every tree parallel to each other even if he has moved the tractor 4 to a new location.
Figure 10 shows a path that the operator could follow in the logging area. By positioning the felled trees in piles that are within range of the middle path, the heavier machines used to pick up the trees only have to use the middle path. This has the advantage of being less damaging to the small trees and undergrowth as well as being faster and more efficient.
In Figure 4, the illustrated hydraulic motor 40 is illustrated enclosed in a cavity 38 of the holder 30 where it is protected from tree branches and tree trunks that can damage the hydraulic motor 40 or its hydraulic hoses. The gearbox 50 is at least partially housed in the frame 10 and also protected from damage. This arrangement creates a lighter frame than what is commonly found in the prior art. The weight of the felling head 10 is an important feature considering that, when the manipulator arm 5 is fully extended, the weight of the felling head 10 applies an enormous force to the entire structure of the tractor 4. This arrangement is also very compact and 1 S allows the operator to manipulate the felling head 10 in dense wooded areas without it getting tangled in branches.
Figure 6 shows the felling head 10 rotated sideways about the axis defined by the drive shaft 45 of the motor 40 and the central gear 54 (shown in Figure 5) of the gearbox 50. Since the inner workings of a planetary gearbox are understood by those skilled in the art, suffice it to say that the torque of the central gear 54 is transferred to the intermediate gears 56 which in turn transfers it to the final gear 52 on which frame 20 is rigidly attached. Frame 20 rotates about the axis of rotation of the drive shaft by following the final gear 52. With this arrangement, the felling head 10 is capable of at least 360 degrees of rotation.
Figure 7 illustrates a variant of the first embodiment of the present invention in which the drive shaft 45 of the motor 40 is connected coaxially to the frame 20 via a bearing-like member 60. The bearing-like member 60 could be a roller bearing, a ball bearing, a journal bearing or simply a low-friction shaft-sleeve arrangement. In this particular variant, the drive shaft 45 is connected to the bearing-like member 60 at the central Tamer gear 66. The inner part 64 of the bearing-like member 60 is affixed to the holder 30 while the outer part 62 is affixed to the frame 20. The drive shaft 45 extends through an aperture in the inner part 64 and is linked to the outer part 62 at a drive shaft housing 66. The torque of the motor 40 is transferred to the frame 20 by the drive shaft 45 and the outer part fit.
S
Figures 8 and 9 illustrate a second embodiment of the present invention in which the axis of rotation of the drive shaft 45 of the motor 40 is not coaxial with the axis of rotation of the frame 20. In this second embodiment, a transmission is thus provided to connect the offset drive shaft 45 to the frame 20. In the variant illustrated in Figures 8 and 9, the transmission comprises a plurality of gears. In this particular variant, the motor 40 is housed in the cavity of the holder 30 but the drive shaft 45 of the motor 40 is not coaxial with the axis of rotation of the frame 20.
A small gear 72 is attached to the drive shaft 45 of the motor 40. This small gear 72 is coupled to the intermediate gear 75 through the lower case gear 74. The upper case gear 76 of the intermediate gear 75 is coupled to the large gear 70 which is affixed to the frame 20 and imparts the rotational motion to the frame 20. In this arrangement, the torque of the motor 40 is transferred to the drive shaft 45 which transfers it to the lower case gear 74 of the intermediate gear 75 via the small gear 72. The torque is then transmitted to the large gear 70 via the upper case gear 76 of the intermediate gear 75.
In a second variant of the second embodiment, the transmission comprises a chain and sprocket. In a third variant, the transmission comprises a belt-drive mechanism.
The above description of preferred embodiments should not be interpreted in a limiting manner since other variations, modifications and refinements are possible within the spirit and scope of the present invention. The scope of the invention is defined in the appended claims and their equivalents.
Figure 6 is a rear elevational view of the felling head rotating sideways.
Figure 7 is a side elevational view of the motor and bearing-like member arrangement.
Figure 8 is a side elevational view of a motor and gearbox arrangement wherein the motor is not located coaxially with the axis of rotation of the felling head.
Figure 9 is a front elevational view of the motor and gearbox arrangement of Figure 8.
Figure 10 is a top view of the path of the tractor in a logging area and an example of an environmentally-conscious tree piling pattern.
In the drawings, preferred embodiments of the invention are illustrated by way of examples. It is to be expressly understood that the description and drawings are only for the purpose of illustration and are an aid for understanding. They are not intended to be a definition of the limits of the invention.
Description of the Preferred Embodiments Figures 1 and 2 illustrate a first embodiment of a felling head according to the present invention designated comprehensively by the reference numeral 10. The felling head 10 is mounted to a tilting holder 30 which in turn is normally attached to a manipulator arm 5 of a tractor 4 or other such vehicle. The felling head 10 is made of a frame 20 on which is typically mounted a plurality of restraining arms 15 used to restrain the trees as the saw blade located normally at the base 21 of the frame 20 cuts the bottom part of the tree trunk. The frame 20 is provided with a transmission arrangement, for example a gearbox 50. In the illustrated example, the gearbox SO is of planetary type. The planetary gearbox 50 is solidly affixed to the tilting holder 30. The tilting holder 30 has a cavity in which a hydraulic motor 40 is at least partially G
housed. The motor 40 is coupled to the gearbox 50 via a drive shaft 45 which transfers the rotary motion of the motor 40 to the gearbox 50. Since the frame 20 is fixed to the outer shell of the gearbox 50, the frame 20 therefore follows the rotation of the gearbox. The frame 20 rotates about the axis of the drive shaft 45. For the purposes of this specification, this arrangement is termed "coaxial" since the axis of rotation of the drive shaft 45 is in alignment with the axis of rotation of the frame 20. Furthermore, this arrangement permits the frame 20 to rotate at least 360 degrees with respect to the holder 30. Thus, the felling head 10 can be maneuvered into practically any posture for gripping, cutting and manipulating trees.
In normal use, the tractor 4 is positioned near a tree 2. The manipulator arm 5 is extended and the frame 20 of the felling head 10 is positioned preferably parallel to the tree trunk.
Depending on the position of the tractor 4 relative to the tree 2, the felling head 10 may need to be tilted backward or forward and/or sideways.
To control the backward and forward motion of the felling head 10, the operator actuates the hydraulic actuator 8. The holder 30 is linked to the manipulator arm 5 by a pivoting point 32 and to the hydraulic actuator 8 at a pivot point 34 of the holder 30. As the hydraulic actuator 8 pulls or pushes at the pivot point 34, the holder 30 and therefore the felling head 10 rotate about the pivoting point 32. If the operator needs to tilt the felling head 10 sideways, he actuates the hydraulic motor 40. The drive shaft 45 of the motor 40 imparts rotary motion to the gearbox 50 and therefore to the felling head 10.
When the felling head 10 is properly aligned with t:he tree 2, the restraining arms 15 open and grasp the tree 2. In that same motion, the saw located at the base 21 of the frame 20 cuts the tree 2. With the tree cut and firmly held by the restraining arms 15 of the felling head 10, the manipulator arm 5 lifts the tree 4, the motor 40 rotates the frame 20 so that the length of the tree is generally parallel to the ground and then, finally, the manipulator arm 5 lays the tree 4 on the ground in a position that will be easily accessible for the collection vehicle to pick up and carry away. To facilitate the pick-up procedure, it is preferable to make neat piles of trees, having every tree parallel to each other. This is why the sideways rotation, or roll, of the felling head 10 is advantageous. Because the felling head 10 is able to tilt sideways, the operator is able to place every tree parallel to each other even if he has moved the tractor 4 to a new location.
Figure 10 shows a path that the operator could follow in the logging area. By positioning the felled trees in piles that are within range of the middle path, the heavier machines used to pick up the trees only have to use the middle path. This has the advantage of being less damaging to the small trees and undergrowth as well as being faster and more efficient.
In Figure 4, the illustrated hydraulic motor 40 is illustrated enclosed in a cavity 38 of the holder 30 where it is protected from tree branches and tree trunks that can damage the hydraulic motor 40 or its hydraulic hoses. The gearbox 50 is at least partially housed in the frame 10 and also protected from damage. This arrangement creates a lighter frame than what is commonly found in the prior art. The weight of the felling head 10 is an important feature considering that, when the manipulator arm 5 is fully extended, the weight of the felling head 10 applies an enormous force to the entire structure of the tractor 4. This arrangement is also very compact and 1 S allows the operator to manipulate the felling head 10 in dense wooded areas without it getting tangled in branches.
Figure 6 shows the felling head 10 rotated sideways about the axis defined by the drive shaft 45 of the motor 40 and the central gear 54 (shown in Figure 5) of the gearbox 50. Since the inner workings of a planetary gearbox are understood by those skilled in the art, suffice it to say that the torque of the central gear 54 is transferred to the intermediate gears 56 which in turn transfers it to the final gear 52 on which frame 20 is rigidly attached. Frame 20 rotates about the axis of rotation of the drive shaft by following the final gear 52. With this arrangement, the felling head 10 is capable of at least 360 degrees of rotation.
Figure 7 illustrates a variant of the first embodiment of the present invention in which the drive shaft 45 of the motor 40 is connected coaxially to the frame 20 via a bearing-like member 60. The bearing-like member 60 could be a roller bearing, a ball bearing, a journal bearing or simply a low-friction shaft-sleeve arrangement. In this particular variant, the drive shaft 45 is connected to the bearing-like member 60 at the central Tamer gear 66. The inner part 64 of the bearing-like member 60 is affixed to the holder 30 while the outer part 62 is affixed to the frame 20. The drive shaft 45 extends through an aperture in the inner part 64 and is linked to the outer part 62 at a drive shaft housing 66. The torque of the motor 40 is transferred to the frame 20 by the drive shaft 45 and the outer part fit.
S
Figures 8 and 9 illustrate a second embodiment of the present invention in which the axis of rotation of the drive shaft 45 of the motor 40 is not coaxial with the axis of rotation of the frame 20. In this second embodiment, a transmission is thus provided to connect the offset drive shaft 45 to the frame 20. In the variant illustrated in Figures 8 and 9, the transmission comprises a plurality of gears. In this particular variant, the motor 40 is housed in the cavity of the holder 30 but the drive shaft 45 of the motor 40 is not coaxial with the axis of rotation of the frame 20.
A small gear 72 is attached to the drive shaft 45 of the motor 40. This small gear 72 is coupled to the intermediate gear 75 through the lower case gear 74. The upper case gear 76 of the intermediate gear 75 is coupled to the large gear 70 which is affixed to the frame 20 and imparts the rotational motion to the frame 20. In this arrangement, the torque of the motor 40 is transferred to the drive shaft 45 which transfers it to the lower case gear 74 of the intermediate gear 75 via the small gear 72. The torque is then transmitted to the large gear 70 via the upper case gear 76 of the intermediate gear 75.
In a second variant of the second embodiment, the transmission comprises a chain and sprocket. In a third variant, the transmission comprises a belt-drive mechanism.
The above description of preferred embodiments should not be interpreted in a limiting manner since other variations, modifications and refinements are possible within the spirit and scope of the present invention. The scope of the invention is defined in the appended claims and their equivalents.
Claims (14)
1. A felling head for restraining, cutting and manipulating trees, said felling head comprising:
(a) a holder for connection to a manipulator arm;
(b) a motor mounted on said holder, said motor being adapted to impart rotational motion to a frame;
(c) a bearing-like member to rotatably connect said frame to said holder.
(a) a holder for connection to a manipulator arm;
(b) a motor mounted on said holder, said motor being adapted to impart rotational motion to a frame;
(c) a bearing-like member to rotatably connect said frame to said holder.
2. A felling head as recited in claim 1, wherein said motor has a drive shaft, said drive shaft defining a rotational axis about which said frame is rotatably mounted.
3. A felling head as recited in claim 1, wherein said motor has a drive shaft defining a first rotational axis and said frame is rotatably mounted about a second rotational axis wherein said first rotational axis and said second rotational axis are coaxial.
4. A felling head as recited in either of claims 2 or 3, wherein said holder defines a cavity in which said motor is at least partially housed, said drive shaft protruding from said cavity.
5. A felling head as recited in either of claims 2 or 3, further comprising a gearbox.
6. A felling head as recited in claim 4 wherein said gearbox comprises a planetary gear.
7. A felling head as recited in either of claims 5 or 6 wherein said frame defines a cavity in which said gearbox is at least partially housed, said gearbox being adapted to cooperate with said drive shaft.
8. A felling head as recited in claim 1, wherein said motor is radially spaced apart from the axis of rotation defined by the bearing-like member.
9. A felling head as recited in claim 8, further comprising a transmission arrangement cooperating on a first side with said motor and on a second side with said frame.
10. A felling head as recited in claim 8, further comprising a transmission arrangement cooperating on a first side with said motor and on a second side with said bearing-like member.
11. A felling head as recited in either of claims 9 or 10, wherein said transmission arrangement comprises a belt.
12. A felling head as recited in either of claims 9 or 10, wherein said transmission arrangement comprises a gearbox.
13. A felling head as recited in either of claims 9 or 10, wherein said transmission arrangement comprises a chain and sprocket.
14. A felling head as recited in either of claims 9 or 10, wherein said transmission arrangement comprises a rack and pinion.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2242625 CA2242625A1 (en) | 1998-07-09 | 1998-07-09 | Lightweight felling head |
| US09/350,464 US6123124A (en) | 1998-07-09 | 1999-07-09 | Tree felling head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2242625 CA2242625A1 (en) | 1998-07-09 | 1998-07-09 | Lightweight felling head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2242625A1 true CA2242625A1 (en) | 2000-01-09 |
Family
ID=29409601
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2242625 Abandoned CA2242625A1 (en) | 1998-07-09 | 1998-07-09 | Lightweight felling head |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2242625A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8141602B2 (en) | 2008-09-19 | 2012-03-27 | Usinage Gn Roy Inc. | Rotation system for a felling head |
| CN108552009A (en) * | 2018-06-20 | 2018-09-21 | 中国林业科学研究院林业新技术研究所 | Cluster Bamboo cuts machine selectively |
| US10561075B2 (en) | 2014-06-17 | 2020-02-18 | Quadco Inc. | Forestry device with articulated accumulating arm |
-
1998
- 1998-07-09 CA CA 2242625 patent/CA2242625A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8141602B2 (en) | 2008-09-19 | 2012-03-27 | Usinage Gn Roy Inc. | Rotation system for a felling head |
| US10561075B2 (en) | 2014-06-17 | 2020-02-18 | Quadco Inc. | Forestry device with articulated accumulating arm |
| CN108552009A (en) * | 2018-06-20 | 2018-09-21 | 中国林业科学研究院林业新技术研究所 | Cluster Bamboo cuts machine selectively |
| CN108552009B (en) * | 2018-06-20 | 2023-10-03 | 中国林业科学研究院林业新技术研究所 | Concatenation bamboo harvester |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |