FIELD OF THE INVENTION
The present invention relates to land clearing vehicles. More specifically, this invention relates to a tool to be mounted on a land clearing vehicle for extracting tree stumps from the ground, and a track assembly therefor.
BACKGROUND OF THE INVENTION
A wide variety of land clearing vehicles, and clearance tools to be used therewith, have been developed to execute a variety of tasks relating to agricultural, municipal and forestry work. Ultimately, the vehicles in question are designed to work and navigate through rough terrains in order to fulfill their tasks. Consequently, a wide variety of these vehicles are fitted with track systems to improve their maneuverability in such conditions. Though tracked vehicles are not uncommon in the art, certain weaknesses become apparent when these vehicles are put to work in rough conditions, such as, for example, in forestry work where the terrain generally comprises of steep and slippery slopes, rough unlevelled surfaces, and a variety of obstructions and interfering objects scattered throughout the work area. Necessarily, a rugged and highly optimised track system is required to manoeuvre in such conditions if one wishes to protect and extend the lifespan of the track assembly components, while providing for full operability.
Namely, conventional tracked vehicles, generally comprising tracks guided by sets of rollers and driven by drivable sprocket wheels of some type, can often fall victim to malfunctions in rough terrain conditions. For example, branches or debris can become jammed in the track assembly, either between the rollers, or around the sprocket wheel, which can in turn seriously damage the track and its components. Furthermore, insufficient protection of the track driving means, whether hydraulic or mechanical, often leads to damages induced by terrain obstacles and debris striking and obstructing the elements in question.
Another deficiency observed in conventional vehicles is the short lifespan of the track-driving sprocket wheels. For instance, the sprocket wheels of existing vehicles of this type are generally installed such that a significant fraction of the vehicle's weight is supported by the sprocket wheels, drastically reducing their lifespan as they must not only bear the weight and tension of the track, but also bear a significant portion of the vehicle's weight as well.
Finally, and more specifically related to forestry and agricultural tools to be mounted on the above vehicles, it is generally cumbersome to approach the task of removing an obstructing tree stump when clearing a particular work area. For instance, various clearing tools have been developed to take down trees and clear gathered debris, either removing it or mulching it with heavy-duty mulchers, but it is generally awkward to approach the task of removing leftover stumps with conventional equipment. A simple and efficient tree stump removal tool that can be mounted on a vehicle, or combined with other mounted tools, could efficiently tackle all elements of land clearing and significantly increase productivity and efficiency.
SUMMARY OF THE INVENTION
In order to address the above and other drawbacks, and in accordance with the present invention, there is disclosed a track assembly for a tracked vehicle, the track assembly comprising an elongated trackframe comprising an inner panel and an outer panel, a set of bottom rollers rotatably mounted between a bottom inner edge of the inner panel and a bottom outer edge of the outer panel, and at least one roller guard mounted on the trackframe, the roller guard extending substantially downwardly from the trackframe to at least partially protect the rollers.
There is also disclosed a track assembly for a tracked vehicle, the track assembly comprising an elongated trackframe and a hollow protective casing at a first end thereof, a track, a track driving means comprising a motor, a drive train and a drivable sprocket wheel drivingly coupled thereto for driving the track, wherein the motor and the drive train are mounted in, and protected by, the protective casing.
Additionally, there is also disclosed a track assembly for a tracked vehicle, the track assembly comprising a trackframe and a set of rollers rotatably attached thereto, an automatic tensioner assembly comprising a restoring arm retractably coupled to the trackframe and extending outwardly therefrom to a tensioner wheel rotatably fastened thereto at a distal end thereof, and a track comprising an inner track surface moveably mounted on the tensioner wheel and the rollers.
Furthermore, there is disclosed a track assembly for a tracked vehicle, the track assembly comprising a substantially horizontal elongated trackframe and a set of rollers rotatably fastened thereto, a track comprising an inner track surface, a track driving means comprising a drivable sprocket wheel for driving the track, the sprocket wheel being rotatably mounted at a first distal end of the trackframe. The track inner surface is moveably mounted on the rollers and drivingly coupled to the sprocket wheel. The sprocket wheel is mounted to the trackframe such that when the vehicle is on a horizontal flat surface, a segment of the track vertically below a bottommost point of the sprocket wheel is free from contact with the surface.
There is also disclosed a tree stump extraction tool to be mounted on a vehicle having activation means for activating the tool, the tool comprising an upper end and a lower end, pivoting means defining a pivot axis at the upper end for pivotally mounting the tool to the vehicle, and a set of substantially parallel teeth solidly coupled to the lower end, each tooth comprising a pointed end extending generally forwardly from the bottom end. When the tool is activated by the activation means to pivot the tool in an upward or downward motion, the teeth are respectively rotated upwardly or downwardly about the axis.
Additionally, there is also disclosed a method for extracting a tree stump from the ground comprising the steps of:
- a) providing a tool pivotally mounted on, and activated by, a vehicle having activation means for activating the tool, the tool comprising an upper end and a lower end, pivoting means defining a pivot axis at the upper end for pivotally mounting the tool to the vehicle, and a set of substantially parallel teeth solidly coupled to the lower end, each tooth comprising a pointed end extending generally forwardly from the bottom end;
- b) targeting the tree stump to be extracted;
- c) moving the vehicle toward the stump such that the teeth engage a bottom section of the stump; and
- d) activating the activation means for pivoting the tool, upwardly rotating the teeth about the axis, and consequently at least partially extracting the stump from the ground.
Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of illustrative embodiments thereof, given by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration an illustrative embodiment thereof, and in which:
FIG. 1 is a front perspective view of a land clearing vehicle in accordance with an illustrative embodiment of the present invention;
FIG. 2 is another front perspective view of the land clearing vehicle of FIG. 1;
FIGS. 3
a and 3b schematically illustrate the sequential operation of a tree stump extraction tool, of the land clearing vehicle of FIG. 1, also in accordance with an illustrative embodiment of the present invention;
FIGS. 4
a and 4b are respectively exploded and assembled perspective views of a track assembly (without the track), of the land clearing vehicle of FIG. 1, also in accordance with an illustrative embodiment of the present invention;
FIG. 5 is a rear perspective view, partly exploded, of the track assembly of FIG. 4b being fitted to the land clearing vehicle in accordance with an illustrative embodiment of the present invention;
FIG. 6 is a bottom perspective view of a land clearing vehicle without one of its track assemblies to better illustrate the bottom of the land clearing vehicle, in accordance with an illustrative embodiment of the present invention;
FIGS. 7
a and 7b are side views of the track assembly, with a rear sprocket wheel thereof shown respectively in lowered and raised positions thereof, in accordance with an illustrative embodiment of the present invention; and
FIG. 7
c is an enlarged view of the circled area in FIG. 7b, showing the rear sprocket wheel of the track assembly, in its raised position.
DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS
Referring now to FIG. 1, a land clearing vehicle, generally referred to using the numeral 10, and in accordance with an illustrative embodiment of the present invention, will now be described. The land clearing vehicle 10 is generally a heavy-duty vehicle configured for traveling and maneuvering in rough terrain conditions. The vehicle generally comprises a set of tracks 12, mounted around trackframes 14, securely linking the tracks to a main body 16 of the vehicle. The main body 16 generally comprises a cabin 18, from which an operator may bring the vehicle to complete various tasks through various controls (not shown), and a ventilated casing 20 for housing, amongst other things, the vehicle's engine, cooling system, electronics, hydraulic system, and other components of the sort. At the front of the vehicle, a lifting arm 22, generally hydraulically activated by respective hydraulic lift 23 and tilt 24 cylinders, allows for the installation and manipulation of various tools to be used in conjunction with the land clearing vehicle. In this particular illustrative embodiment, the vehicle is fitted with a heavy-duty mulching machine 26 at the end of lifting arm 22, activated by a protected drive shaft (hidden by protective drive shaft guard 27), and a tree stump removal tool 28, which is hydraulically activated by a set of hydraulic cylinders 30 fastened atop the mulching machine 26.
As it will become apparent to a person skilled in the art, a land clearing vehicle, such as the one illustrated at 10 in FIG. 1, will be powered accordingly for the task to be completed. In this particular illustrative embodiment, the vehicle 10 comprises a hydrostatic drive system powered by a heavy-duty diesel engine, such as a Cummins™ 550 horsepower diesel engine. The engine drives two closed-circuit variable flow pumps hydraulically coupled to two hydraulic piston motors (reference 126 of FIG. 3), such as the Series 90 100 CC pumps and two-speed motors by Sundstrand™. The two pumps and motors, controlled by electronic joystick-type controls, independently drive a set of sun gear assemblies 32, each protected by a driven outer shell 33, which are ultimately coupled to the tracks 12 by a set of sprocket wheels 34 securely fastened thereon. Within each sun gear assembly 32, a parking/emergency brake is provided and applied to the motors when the diesel engine is not in operation.
Referring now to FIG. 2 in conjunction with FIG. 1, and in accordance with an illustrative embodiment of the present invention, the land clearing vehicle 10 is again fitted with both a mulching machine 26 and a tree stump removal tool 28 pivotally mounted at the front thereof. The stump removal tool 28 is comprised of a generally vertical comb-like structure 38, manufactured of a considerably strong and resilient material such as steel or other industrial strength materials of the like, integrally coupled at a rear end thereof to a base 40 substantially perpendicularly oriented thereto. The base 40 then links the comb-like structure 38 to two (2) hydraulically activated L-shaped arms 42 which provide mounting and pivoting means to the stump removal tool 28. At a bottom free end of the tool 28, the comb-like structure 38 terminates in a set of pointed teeth 44, usually between four (4) and six (6), generally extending roundly forwardly from the structure 38. Additional transversal supports, possibly in the form of horizontal stabilizer rods or bars, may be added along the length of the comb 38 to reinforce the structure 38.
Still referring to FIGS. 1 and 2, the stump removal tool 28 is pivotally and solidly mounted to the mulching machine 26 using a set of cylindrical bushings 46 fitted through the respective vertices 47 of the L-shaped arms 42, defining a pivot axis 50. The set of hydraulic cylinders 30, are coupled to upper ends 52 of the L-Shaped arms 42, and thus above axis 50, providing leverage for the stump removal tool 28 about the pivot axis 50, which essentially acts as a fulcrum for the rotation of the tool 28. Necessarily, when the hydraulic cylinders 30 apply a pulling force on the L-shaped arms 42, the tool 18 is rotated upwardly about axis 50 and the teeth 44 are brought up from the ground. Clearly, a person of skill in the art will understand that the tool 28 could also be set up to be activated by a set of hydraulics connected below the pivot axis, in which case a pushing force would need to be applied to the tool 28 in order to raise the teeth 44. Furthermore, although the pivoting means are illustrated in this embodiment as being hydraulic in nature, other pivoting means, such as mechanical or pneumatic means, could also be used to activate the tool 28.
Now referring mainly to FIG. 3, but in conjunction with FIGS. 1 and 2, and in accordance with an illustrative embodiment of the present invention, the operation of the tree stump removal tool 28 will now be presented. In FIG. 3a, the tree stump removal tool 28, presented here as pivotally mounted to the mulching machine 26, is shown to move forward along arrow A toward a tree stump 46. As the teeth 44 of the tool 28 are moved forward, they engage a bottom portion 48 of the tree stump 46. In FIG. 3b, the hydraulic cylinders 30 are activated such that the teeth 40 are rotated upwardly along arrow B, partially extracting the stump 46 from the ground. In order to fully extract the stump 46 from the ground, the tool 28 may be further moved toward the stump 46, maintaining engagement therewith, and further rotated upwardly until the stump 46 is fully extracted. Once fully extracted, the stump 46 is either removed from the site using appropriate machinery, or again mulched using, for example, a mulching machine such as the one illustrated in FIGS. 1, 2 and 3.
Referring now to FIGS. 4a and 4b, a track assembly for a land clearing vehicle such as vehicle 10, generally referred to using the numeral 60, and in accordance with an illustrative embodiment of the present invention, will now be described. The track assembly 60 generally comprises trackframe 14, a set of upper rollers 64 and bottom rollers 66 rotatably coupled thereto, a tensioner assembly 68 retractably coupled at the front end 70 of the trackframe 14 and a track driving system 72 located at the rear end 74 of same. The trackframe 14, which is essentially used to hold and house the majority of track assembly components, generally consists of a hollow elongated rectangular box having side and top panels 76 and 78 respectively, the latter of which comprising an open-ended rectangular cutout 79 at the front thereof for accepting part of the tensioner assembly 68 therein (discussed further hereinbelow). An additional set of guards 80 is also securely fitted to the bottom of the side panels 76 at the front end 70 of the trackframe 14.
The two upper rollers 64, each generally comprising a set of double rollers 81 having exterior track guiding edges 82 and rotating freely about a same axle 83, are rotatably coupled to the trackframe 14 by coupling the roller axles 83 to respective roller supports 84 integrally fitted to the top panel 78 of the trackframe 14. The bottom rollers 66, also generally comprising double rollers 86 having exterior track guiding edges 87 and rotating freely about a same axle 88, are rotatably coupled to the trackframe side panels 76 by a set of axle supports 90 securely fastened to the bottom of same using a set of bolts or other fastening means of the like. In this illustrated embodiment, the vehicle 10 is comprised of eight (8) bottom rollers 66, though an alternative illustrative embodiment could comprise more than eight (8) bottom rollers, such as eleven (11) bottom rollers 66. Due to the high number of bottom rollers 66, the weight of the vehicle 10 is better distributed on the bottom track. Furthermore, the high number of bottom rollers 66 improves the vehicle's ability to manoeuvre in rough terrain conditions, providing greater support, and thus increased durability for the track 12.
Additionally, still referring to FIGS. 4a and 4b and in accordance with an illustrative embodiment of the present invention, a set of roller guards 92 are fastened to the bottom of the trackframe side panels 76 adjacent guard 80 in order to protect the bottom rollers 66 in rough terrain conditions. In this specific embodiment, a roller guard 92 is generally comprised of a flat elongated structure 94 having a series of arcuate cutouts 96 at the top thereof for accepting the generally circular roller axle supports 90 therein. The cutouts 96 are interspersed between a set of fastening flanges 98 used to securely fasten the roller guard 92 to the bottom of the trackframe side panels 76 using a set of bolts or other fastening means of the like; the cutouts 96 coincide with the axle supports 90 allowing the flanges 98 to be fastened therebetween. Consequently, the top portion 100 of the bottom rollers 66 is efficiently protected by the trackframe side panels 76, whereas the bottom portion 102 of the bottom rollers 66 is efficiently protected by the roller guards 92, significantly reducing the possibility of interference or obstruction from debris, branches, vegetation or other items of the like scattered around the work area. By providing the bottom rollers 66 with such fitted roller guards 92, the efficiency and lifespan of the track assembly 60 is significantly increased.
Still referring to FIGS. 4a and 4b, and in accordance with an illustrative embodiment of the present invention, the tensioner assembly 68 is generally comprised of a tensioner wheel 104 rotatably installed at the distal end 106 of a spring-loaded tensioner arm 108, itself retractably coupled to the front end 70 of the trackframe 14. The tensioner wheel 104 generally consists of an elevated central disc 110 and two (2) lateral discs 112, for coupling with the inner surface of the track 12 (discussed further hereinbelow). A bifurcated wheel coupler 114 rotatably links an axle 116 of the tensioner wheel 104 to the tensioner arm 108. A shaft 118 of the tensioner arm 108 is moveably fitted with a heavy-duty spring 120, which abuts against the proximal end 122 of the wheel coupler 114. The tensioner assembly 108 is then inserted into the front end 70 of the trackframe 14, guided by a set of lateral runners 124 designed to slidably accept the lateral edges of the bifurcated coupler 114 and a shaft guide (not seen) designed to both slidably accept the tensioner shaft 118 and provide a fixed surface upon which the spring 120 may be compressed during tensioner retraction. In its resting position, the tensioner assembly 68 is positioned such that the tensioner wheel 104 may rotate freely within the trackframe top panel opening 79, which allows the tensioner wheel 104 to be partially hidden and protected by the trackframe side panels 76 and guards 80.
Accordingly, and in accordance with an illustrative embodiment of the present invention, the tensioner assembly 68 will provide means for maintaining a substantially constant tension in the track. Consequently, the track 12, and the vehicle 10 it is mounted on, will be provided with better means for addressing and maneuvering in precarious terrain conditions. Furthermore, if an object, such as debris, branches, vegetation, or other items of the like, interferes with, or becomes lodged between, the track 12, the rollers 64, 66, the sprocket wheel 34, the trackframe 14 or any other component of the track assembly 60, the tensioner assembly 68 will automatically retract within the trackframe 14 and release the track 12, thereby reducing the risk of damage to the track 12 and other components of the track assembly 60. As it will now be apparent to a person of skill in the art, other such tensioner assemblies may be developed without departing from the general scope of the illustrated embodiment. For instance, a tensioner assembly generally comprising a tensioner arm and wheel fitted with a hydraulic, pneumatic, or even magnetic restoring system could just as well replace the illustrated spring-loaded mechanism and provide similar advantages.
Still referring to FIGS. 4a and 4b, and in accordance with an illustrative embodiment of the present invention, the track driving system 72 generally comprises a hydraulic motor 126 coupled to a sun gear assembly 32 protected by a driven shell 33, and a sprocket wheel 34 solidly fastened thereon. In order to properly protect the components of the track driving system 72, the motor 126 is securely mounted within a protective casing 128 solidly fastened to the rear end 74 of the trackframe 14. From this protective casing 128, the motor 126 engages the sun gear assembly 32 that drives the protective shell 33 rotatably mounted to the casing 128 through bearings 130, which itself drives the sprocket wheel 34 solidly mounted thereon. A protective casing plate 134 provides protection to motor 126 from the inside of the trackframe 14, while still providing an opening 136 for passing driving hydraulic lines (not seen) from the main body 16 to the motor 126. A protective skate 138 is fastened to the back end 74 of trackframe 14, providing added protection to the sprocket wheel 34 and sun gear assembly 32. Unlike conventional vehicles, the track assembly 60 of the present illustrative embodiment offers the protected track driving system 72 directly within the trackframe 14. Consequently, the track driving system 72 is very well protected by the trackframe 14 and track 12 from interference or obstructions from outside elements such as branches, debris, vegetation, and other items of the like, thereby increasing the lifespan of its components.
Now referring to FIGS. 5 and 6 in conjunction with FIGS. 4a and 4b, and in accordance with an illustrative embodiment of the present invention, the track assembly 60 is securely installed to the main body 16 of the land clearing vehicle 10. A rear suspension shaft 138 is fitted to a cylindrical suspension shaft housing 140 at the rear end 74 of the trackframe 14 and capped with a cap 142, whereas a front suspension arm 144 is secured to a suspension joint 146 at the front end 70 of the trackframe 14, with a pin 147. In order to provide full protection to the vehicle driving means, a pan 148, fastened to the bottom of the land clearing vehicle 10, is fitted such that hydraulic lines (not shown) provided from the hydraulic pumps (also not shown) within the main body 16 to drive the hydraulic motors 126 secured within the protective casing 128, will be guided thereto under full protection by the pan 148.
With reference to FIGS. 4a, 4b and 7, and in accordance with an illustrative embodiment of the present invention, the track 12 is mounted on the track assembly 60, such that it may be guided by the bottom rollers 66, the tensioner wheel 104 and the top rollers 64, and driven by the sprocket wheel 34. Essentially, the track 12 consists of a set of substantially flat and likely ribbed panels 150, on which is mounted a drive chain 152. The teeth 154 of the sprocket wheel 34 drive the track 12 by coupling themselves around hinges 156 of the drive chain 152. The driven track is then guided around the trackframe 14 as outside faces 158 of the drive chain 152 are guided by the respective outside edges 82 and 87 of the top and bottom rollers 64 and 66, and the central disc 110 of the tensioner wheel 104.
In FIG. 7a, the sprocket wheel 34 is level with the rollers. In other words, at point X1 where the drive chain 152 is first grabbed between the two bottommost teeth 160 of the sprocket wheel 34 (or first released when the vehicle 10 is in reverse mode), the track 12 is still in contact with the ground 162. Consequently, the weight of the vehicle is distributed both on the bottom rollers 66 and the sprocket wheel 34, as pressure between the ground and the track 12 at point X1 is directly transmitted to the sprocket wheel 34.
Alternatively in FIG. 7b, the sprocket wheel 34 is raised upwardly, if only by a fraction of an inch, such that at point X2 where the drive chain 152 is first grabbed between the two (2) bottommost teeth 160, the track is not in contact with the ground. In this alternative embodiment, the sprocket wheel 34 does not directly bear any of the vehicle's weight as there is no direct pressure transfer from the ground 162 to the sprocket wheel 34. As a result of the sprocket wheel configuration of FIG. 7b, the sprocket wheel lifespan is drastically increased, reportedly up to four times the lifespan of a sprocket wheel configured as in FIG. 7a.
Accordingly, two particular features help distinguish the configuration of FIG. 7b from the configuration of FIG. 7a to determine whether any of the vehicle's weight is being applied to the sprocket wheel 34. Firstly, the track 12 of FIG. 7b, better seen in FIG. 7c, makes an angle A with the ground 162 between the last roller 164 and the sprocket wheel 34. Though this angle A may be small, it suffices to bring the track 12 away from the ground at the first point of contact X2 with the sprocket wheel 34. In the illustrated embodiment, the vertical distance Z between the track 12 and the ground 162 at the point X2 is generally between one quarter (¼) inch and three (3) inches. In an alternative illustrative embodiment of the present invention, the distance Z is between one quarter (¼) inch and one (1) inch. In a further alternative illustrative embodiment of the present invention, the distance Z is about three quarter (¾) inches.
Secondly, if one observes the bottommost hinge-receiving surface 166 of the sprocket wheel 34, that is the rounded track-bearing surface between the two (2) bottommost teeth 160, one observes in FIGS. 7b and 7c that the critical hinge 168 is not fully inserted between the teeth 160, observing a distance Y therebetween, indicating that no direct pressure from the ground is applied at that point. These two characteristics, observed independently or simultaneously, imply that no direct pressure is applied to the sprocket wheel 34 from the ground 162, and that the sprocket wheel will benefit from an increased lifespan.
As described hereinabove with reference to the cited Figures, the track assembly 60 of the illustrated embodiments presents various protective measures for insuring an optimal durability of the track assembly components. Namely, the track assembly 60 provides a fully protected track driving system, a set of roller guards 92 for protecting the bottom rollers 66, a tensioner assembly 68 that provides added protection to the track 12 and other track assembly components, and a driving sprocket wheel 34, elevated to significantly increase its lifespan. Furthermore, a novel tree stump removal tool 28 is provided to increase the productivity and efficiency of the land clearing vehicle 10.
While this invention has been described with reference to the illustrative embodiments, this description is not intended to be construed to a limiting sense. Various modifications or combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the described invention encompass any such modifications or embodiments.
Patent Application
20070029878
