FIELD OF THE INVENTION

[0001] This invention is generally directed to a system for collecting and removing wood waste generated by a portable wood waste reduction apparatus, such as, for example, a grinding, mulching, or comminuting apparatus.

BACKGROUND

[0002] The challenge of clearing land that is allocated for various types of commercial or residential use is increasingly prevalent, because of the rising pace of new construction and the associated demand for residential landscaping and tree removal operations, hi the modern practice of removing trees, it is possible to cut a tree trunk at or near ground level. However, the tree stump that remains in the ground is difficult to remove or destroy. Stump grinders have been employed to remove and destroy such tree stumps. Commonly, these devices employ some means of grinding the tree stump in order to prevent re-growth, allow soil tillage, allow building construction, and allow for completion of desired landscaping over the stump site. Most types of prior art stump grinders employ rotating circular wheels having grinding teeth located thereon.

[0003] Generally, stump grinders for residential use are not capable of collecting the wood waste that is generated as a result of grinding the stump. This wood waste typically falls over the ground surrounding the site of the tree stump. Leaving this wood waste on the ground is particularly unacceptable when the stump grinding occurs as part of a residential tree removal or

landscaping operation. For this reason, the wood waste is typically collected and removed manually by one or more workers when stump grinding occurs on residential property. Generally, the wood waste that is generated by stump grinding on residential properties is raked and shoveled by workers into a wheelbarrow and/or truck, which is time consuming and costly. This inefficiency adds substantially to the overall cost of land clearing or residential tree removal operations.

[0004] U.S. Patent No. 4,355,670 to Ohrberg et al. provides a collection means for collecting some of the fragmented wood waste produced by a fragmenting means. The collecting means relies on the fragmenting means to fling the fragmented wood in a forward and upward direction into a deflector means, to be deflected backward into a collecting passageway and into the collecting plenum. Some fragmented wood is flung away from the deflector means and/or falls to the ground. As a result, such an arrangement is not efficient and cannot ensure that the fragmented wood created by the fragmenting means will be properly collected. Moreover, the apparatus exemplified in Ohrberg et al is not suitable for reduction of wood waste on home sites in suburbia, owing to the size and complexity of mobile, self -feeding machinery. Residential properties in suburbia and elsewhere, require the use of wood waste reduction machinery that is more compatible with the safety requirements of these locations, owing to their smaller size and the proximal location of home and other structures.

[0005] U.S. Patent No. 4,683,924 to Cornelius discloses a cutting and a chipping apparatus contained within a housing having blower units to facilitate the advancement of the wood chips through the housing. This apparatus provides a means for conveying and removing fragmented wood from a wood chipper contained within a housing, but it does not provide a means for collecting fragmented wood produced outside the housing, such as that produced by a stump grinder. The apparatus is well suited for wood chipper operations in the upper reaches of a tree, but it is not readily applicable or adaptable to stump grinding operations on residential property.

" ^"'" [do ^' bθ] ^{'1 '''} tne wόod ^' wast'e 'uWis generated by stump grinders is a shredded wood product that contains some soil and is suitable for use as mulch because it has sufficient surface area exposed to the action of bacteria and fungi that live in the soil. The bacteria and fungi degrade dead wood to replenish the top soil. The wood product produced by the action of stump grinders could, therefore, be deployed more readily as mulch for landscaping purposes if the means for its collection were more efficient. Therefore, there is a need for machinery that can act effectively in conjunction with a portable wood waste reduction apparatus, such as, for example, a grinding, mulching, or comminuting apparatus, to collect and remove wood waste.

SUMMARY

[0007] The present invention is an apparatus for the collection and removal of wood waste that is generated by a portable wood waste reduction apparatus, such as, for example, a grinding, mulching, or comminuting apparatus. In one embodiment, the wood waste collection and removal apparatus works in conjunction with conventional tree stump grinders to collect and remove wood waste that is generated by tree stump grinders. In another embodiment, the wood waste collection and removal apparatus is incorporated with a tree stump grinder to collect, convey and remove wood waste discharged by the tree stump grinder.

[0008] In accordance with one embodiment of the present invention, the wood waste collection apparatus includes a retractable scoop chute, a conveyance chute and a discharge chute. The retractable scoop chute is positioned behind the grinding mechanism of a tree stump grinder and directs the wood waste toward the conveyance chute. The conveyance chute conveys wood waste from the retractable scoop chute to the discharge chute. The discharge chute directs wood waste from the conveyance chute to a collection area or a collection vehicle that can remove the wood waste from the site.

[0009] According to another aspect of the invention, the retractable scoop chute includes a floor plate, two flexible side walls and a flexible top. Preferably, the floor plate is

made from metal, or other suitable hard material, and is tapered toward the end of the scoop chute connected to the conveyance chute. In one embodiment, the side walls are made of flexible accordion skirts so that when the scoop chute is retracted (i.e., in the non-operating position) the side walls are folded up and when the scoop chute is extended (i.e., in the operating position) the side walls are un-folded. Preferably, the top is made from a flexible material. The floor plate, side walls and top combine to form a scoop chute enclosure that preferably tapers toward, and is connected to, the conveyance chute.

[0010] The retractable scoop chute is positioned behind a tree stump grinding mechanism, collects wood waste that is discharged by the tree stump grinding mechanism, and directs the wood waste toward the conveyance chute.

[0011] According to one embodiment of the invention, the retractable scoop chute can be lowered, by manual operation of a lever or by mechanical means, to a position proximal to the tree stump grinding mechanism. This may include a lower, leading edge of the scoop chute being in contact with the ground or being just above the ground (i.e., about an inch from the ground). The enclosure of the retractable scoop chute is connected to the conveyance chute.

[0012] According to another aspect of the invention, the conveyance chute is a tubular enclosure that has a conveyance mechanism that delivers the wood waste from the scoop chute to the discharge chute. One embodiment of the conveyance mechanism is a mechanically driven conveyor belt along the floor of the conveyance chute! The conveyor belt conveys wood waste from the scoop chute, through the conveyance chute, and into the discharge chute. Another embodiment of the conveyance mechanism is an industrial strength vacuum that creates sufficient negative pressure within the conveyance chute to aspirate the wood waste from the scoop chute to the conveyance chute, and out through the discharge chute. Alternatively, the conveyance mechanism may be a blower, such as an industrial strength blower, that can create enough force to convey the wood waste from the scoop chute to the conveyance chute, and out through the discharge chute. Also, the conveyance mechanism may employ both a conveyor belt

and a vacuum/blowef ^' fo move ffie ^' wδbd waste from the scoop chute to the conveyance chute, and out through the discharge chute. Furthermore, the conveyance mechanism may be any conventional mechanism or combination of mechanisms that may properly convey wood waste away from the scoop chute, through the conveyance chute, and out through discharge chute.

[0013] According to another aspect of the invention, the discharge chute is an enclosure that is connected to the conveyance chute. The discharge chute guides wood waste that moves out of the conveyance chute to a collection area or a collection vehicle that can remove the wood waste from the site.

[0014] According to another aspect of the invention, the wood waste collection apparatus/system may comprise a kit that can be mounted on an existing tree stump grinder. This embodiment allows the wood waste collection apparatus/system to be incorporated into an existing stump grinder without making any or only minor structural modifications to the stump grinder. Furthermore, the wood waste collection and removal kit may be sold separately to tree stump grinder owners, whose tree stump grinders do not have the capacity for wood waste collection and removal.

[0015] One advantage of the present invention is that it allows for concurrent tree stump grinding, and wood waste collection and removal. Also, the stump grinder with wood waste collection and removal system in accordance with the present invention provides a means for grinding a tree stump while simultaneously clearing and leveling a tree stump site. Therefore, the present invention makes tree stump grinding operations more efficient and less costly. Furthermore, wood waste that is suitably shredded by the tree stump grinding operation and is collected by the wood waste collection and removal system may be sold as mulch for landscaping the customer's property or any other property in the future, as described in detail above.

[0016] Additional features of the present invention are set forth below.

[0017] Fig.l is a perspective view of a tree stump grinder with an exemplary embodiment of the wood waste collection and removal apparatus that employs a conventional industrial vacuum;

[0018] Fig. 2 is a top view of the embodiment of Fig. 1 ;

[0019] Fig. 3 is a cross-sectional side view of the embodiment of Fig. 1;

[0020] Fig. 4 is a side view of a tree stump grinder with another exemplary embodiment of the wood waste collection and removal apparatus that employs a conveyor belt;

[0021] Fig. 5 is a top cutaway view of the embodiment of the wood waste collection and removal apparatus of Fig. 4;

[0022] Fig 6. is another exemplary embodiment of the wood waste collection and removal apparatus; and

[0023] Fig. 7 is yet another exemplary embodiment of the wood waste collection and removal apparatus.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0024] The present invention is directed to a wood waste collection apparatus 1. In the preferred embodiment, the wood waste collection apparatus 1 is mounted on a portable wood waste reduction apparatus, such as, for example, a grinding, mulching, or comminuting apparatus 2. In one exemplary embodiment described below, the wood waste collection apparatus 1 is mounted on a conventional tree stump grinder 2 to collect, convey and remove wood waste that is generated by the tree stump grinder 2. The present invention allows simultaneous tree stump grinding, and wood waste collection and removal operations.

[0025] Figs.1-3 show an exemplary embodiment of the wood waste collection and removal apparatus 1. As shown in the embodiment of Fig.l, the wood waste collection and

removal apparatus 1 can be fitted ^' ό ^' h a ^" stump grinder 2, such as a conventional tree stump grinder. As shown in Fig.l, the wood waste collection and removal apparatus 1 includes a retractable scoop chute 4, a conveyance chute 5, and a discharge chute 6. In the embodiment of Fig. 1, the wood waste collection system 1 includes a conveyance mechanism 7, such as, for example, a blower/vacuum or an industrial blower/vacuum 15. Fig. 1 also shows a conventional tree stump grinder 2 having a grinding mechanism 3.

[0026] As shown in Figs. 1-3, the retractable scoop chute 4 is positioned behind the grinding mechanism 3 of the tree stump grinder 2. The retractable scoop chute 4 includes a floor plate 11, two flexible side walls 10 and a top (not shown) that combine to form an enclosure 8. The enclosure 8 has a front opening 9 for receiving wood waste. Preferably, the floor plate 11 is made from metal or other suitable hard material and is tapered toward the end connected to the conveyance chute 5. The floor plate 11 includes a front, leading edge 12. As shown in Fig. 3, the front, leading edge 12 may be in contact with the ground or may be located just above the ground (i.e., about an inch or less from the ground) when the retractable scoop chute 4 is lowered into the operating position.

[0027] For example, the floor plate 11 can be spring-loaded to ensure that the front, leading edge 12 maintains contact with the ground. Alternatively, spacer wheels (not shown) can be provided at the leading edge 12 of the scoop chute 4 to maintain the leading edge 12 of the floor plate 11 adjacent to the ground. The diameter of the wheels determine the gap or clearance between the leading edge 12 and the ground and the wheels also facilitate movement of the scoop chute 4 over the ground. Preferably the front, leading edge 12 is constructed to prevent the leading edge 12 from digging into the ground. For example, the front, leading edge 12 can include a rounded edge, curved upward edge, wheels, rollers, or other suitable means to prevent the front, leading edge 12 from digging into the ground and to facilitate movement of the scoop chute 4 over the ground.

[0028] As ^"' sfϊbwri in Fig ^' s. ^" l and 3, the side walls 10 of the scoop chute 4 are made of flexible accordion skirts that fold up when the scoop chute 4 is retracted and unfold when the scoop chute 4 is extended. Preferably, in embodiments having a scoop chute top, the top of the scoop chute (not shown) is made from a flexible material. Preferably, the retractable scoop chute 4 is broadest at its leading edge 12, closest to the stump grinding mechanism 3, and then tapers toward the back to form a funnel that leads into the conveyance chute 5. The retractable scoop chute 4 collects wood waste that is discharged by the tree stump grinding mechanism 3, and directs the wood waste toward the conveyance chute 5.

[0029] The retractable scoop chute 4 can be lowered, for example, by manual operation of a lever 13 or by screw and knob type mechanical means 14, to a position proximal to the discharge of the tree stump grinding mechanism 3, and preferably in contact with or adjacent with (i.e., about an inch from) the ground. The enclosure 8 of the retractable scoop chute 4 is connected to the conveyance chute 5.

[0030] As shown in Figs. 1-3, the conveyance chute 5 is connected to the retractable scoop chute 4. As shown, the conveyance chute 5 is a substantially tubular enclosure that delivers or directs wood waste from the retractable scoop chute 4 to the discharge chute 6.

[0031] As shown in Figs. 1-3, the discharge chute 6 is an enclosure that is connected to the conveyance chute 5. The discharge chute 6 guides wood waste moving out of the conveyance chute 5 to a collection area or a collection vehicle that can remove the wood waste from the site. In an alternative embodiment (not shown), a leaf-vac type vacuum/blower may be disposed in-line within the discharge chute. This arrangement would allow wood waste that is being generated by the grinding mechanism to be drawn under vacuum toward the vacuum/blower, allow the wood waste to pass through the vacuum/blower, and then blow the wood waste out of the discharge chute.

[0032] Preferably, the conveyance chute 5 has a conveyance mechanism 7 to assist with the delivery of the wood waste from the retractable scoop chute 4 to the discharge chute 6. In the

exemplary embodiment ofFig ^' s ^' . ^' 'i-3, the conveyance mechanism 7 is an industrial strength vacuum 15 that creates sufficient negative pressure within the conveyance chute 5 to aspirate the wood waste from the retractable scoop chute 4 to the conveyance chute 5, and out through the discharge chute 6.

[0033] Fig. 4 shows a tree stump grinder 2 with another embodiment of the wood waste collection and removal apparatus 1. In the embodiment of Fig. 4, the conveyance mechanism 7 is a mechanically driven conveyor belt 16 along the floor of the conveyance chute 5. The conveyor belt 16 may be driven by a motor or engine (not shown). The conveyor belt 16 conveys wood waste from the retractable scoop chute 4, through the conveyance chute 5, and into the discharge chute 6. The conveyor belt 16 may include one or more sections (not shown).

[0034] Fig. 5 shows a cutaway top view of the scoop chute 4, conveyance chute 5 and discharge chute 6 of the embodiment of Fig. 4, revealing the conveyor belt 16. As shown in Fig. 5, the scoop chute 4 is positioned behind the grinding mechanism 3 of the tree stump grinder 2 and is in direct communication with the conveyance chute 5. The conveyance chute of the embodiment of Fig. 4 comprises a mechanically driven conveyor belt 16 along the floor of the conveyance chute 5. The conveyance chute 5 is in direct communication with the scoop chute 4 and discharge chute 6. The scoop chute 4, conveyance chute 5 and discharge chute 6 are connected together to form a system that collects, conveys and removes wood waste generated by the operation of a tree stump grinder 2.

[0035] Alternatively, the conveyance mechanism 7 may employ both a conveyor belt 16 and a vacuum/blower 15 to move the wood waste from the scoop chute 4 to the conveyance chute 5, and out through the discharge chute 6. Furthermore, the conveyance mechanism 7 may be any conventional mechanism or combination of mechanisms that may properly convey wood waste away from the retractable scoop chute 4, through the conveyance chute 5, and out through discharge chute 6.

[0036] In ariδthef ^' emibodϊinent, the wood waste collection and removal apparatus 1 includes a kit 17 that can be mounted on or conjoined to an existing tree stump grinder 2. Fig. 6 shows one embodiment of the wood waste collection and removal kit 17. According to the embodiment of Fig. 6, the kit 17 comprises a retractable scoop chute 4 and conveyors 18, 19. The retractable scoop chute 4 may be positioned behind the grinding mechanism 3 of the tree stump grinder 2. As shown in Fig. 6, a first conveyor 18 is positioned across the back of the retractable scoop chute 4 and receives wood waste discharged by the grinding mechanism 3 into the scoop chute 4. As shown in Fig. 6, the first conveyor 18 conveys wood waste to a second conveyor 19 that is positioned along the length of the tree stump grinder 2. The second conveyor 19 is preferably inclined upward from front to back so that the wood waste may be conveyed into, for example, a truck.

[0037] Fig. 7 shows another embodiment of the wood waste collection and removal kit 17. According to the embodiment of Fig. 7, the kit 17 includes a retractable scoop chute 4 and conveyors 20, 21. The retractable scoop chute 4 is positioned behind the grinding mechanism 3 of the tree stump grinder 2. As shown in Fig. 7, the first conveyor 20 is positioned behind the retractable scoop chute 4 and is held below the tree stump grinder 2 by conveyor supports 22. Also, as shown in Fig. 7, a second optional conveyor 21 is positioned following the first conveyor 20 and is inclined upward to convey wood waste into, for example, a truck.

[0038] In another embodiment of kit 17 (not shown), the conveyance mechanism could include a vacuum/blower and/or a combination conveyor and vacuum/blower for conveying the wood waste generated by the grinding mechanism to an area for removal.

[0039] Although the invention has been described with reference to exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed to include other variants and embodiments of the invention, which may be made by those skilled in the art.