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United States Patent |
5,010,931
|
Hooser
|
April 30, 1991
|
Portable stump remover
Abstract
A portable, self-contained stump remover, that may be hand held by the
operator, has an engine driven cutting device whose cutting teeth rotate
through a circular path at least a part of which lies below a lower base
surface that engages and rests on a tree stump when the stump remover is
placed on the stump by the operator. By manually moving the stump remover
across the stump so that the rotating cutting teeth follow the base
surface, which surface serves to support, guide and stabilize the stump
remover, the stump will be cut away and ground down to the cutting depth
determined by the extent to which the cutting teeth project below the base
surface.
Inventors:
|
Hooser; Steven M. (1 S. 726 Ott Ave., Glen Ellyn, IL 60137)
|
Appl. No.:
|
573107 |
Filed:
|
August 28, 1990 |
Intern'l Class: |
B02C 001/04 |
Field of Search: |
37/2 R
241/101.7,168,169.1,278 R,294,296
144/2 N,208 R,208 C,218,231,241
|
References Cited
U.S. Patent Documents
3911979 | Oct., 1975 | Rousseau | 144/2.
|
4530385 | Jul., 1985 | York | 144/2.
|
4621668 | Nov., 1986 | York | 144/3.
|
4681145 | Jul., 1987 | York | 144/2.
|
Foreign Patent Documents |
803907 | Feb., 1981 | SU.
| |
Other References
Advertising Brochure, undated, for Rayco RG 1620(Jr), Stump Cutter,
Manufactured by Rayo of Wooster, Ohio.
Advertising Brochure, undated, for "Little David", Stump Remover made by
Promark Products of Covina, Calif.
|
Primary Examiner: Bray; W. Donald
Parent Case Text
This application is a continuation, of application Ser. No. 07/466,462,
filed 01/16/90.
BACKGROUND OF THE INVENTION
This invention relates generally to apparatus for removing tree stumps and
roots and, more particularly, to a portable, self-contained stump remover
that cuts and grinds a tree stump and may be hand held by the operator.
Prior portable tree stumpremovers, of the type that cut, grind and mill
away a stump, are of complicated construction and are usually relatively
large, cumbersome, heavy and expensive. Wheels are customarily employed to
transport the stump remover to a tree stump and to support the stump
remover during the cutting process. Many of these removers must be towed
to and from the job site and many have no independent built-in driving
power source and must be driven or powered by auxiliary equipment, such as
by the power take off shaft of a tractor.
In contrast, the stump remover of the present invention exhibits none of
these disadvantages and instead provides a unique stump remover of
relatively simple and inexpensive construction, and which is small, light
weight and entirely self-contained, thereby requiring no external power
source whatsoever. Moreover, the stump remover can be handled by a single
person (the operator) and, in fact, may be hand held by that person during
cutting of a tree stump. Because of its physical size and weight, the
stump remover of the invention may be transported to and from the job site
in the trunk of an ordinary passenger automobile with the trunk lid
closed, and this is possible even if the automobile is a sub-compact.
SUMMARY OF THE INVENTION
The invention proves a portable, self-contained stump remover which is
manually movable by an operator across a tree stump to effect grinding
thereof. The stump remover comprises a base element having a lower base
surface for engaging and resting on the top of the tree stump when the
stump remover is placed on the stump. The base element may take any of a
variety of different forms, such as a plate, strip, bar, rod or merely an
edge portion, in order to provide a suitable lower base surface for
contacting and resting on the stump. There is at least one rotatable
cutting device having a plurality of cutting teeth. Driving means (such as
a small gasoline engine whose output shaft is mechanically coupled, either
directly or indirectly, to the cutting device) rotates the cutting teeth
through a circular path at least a portion of which path extends below the
lower base surface provided by the element. A cutting depth is defined by
the extent to which the rotating cutting teeth project below the base
surface. When the operator places the stump remover on the tree stump so
that the lower base surface engages the stump, the base surface
effectively supports, guides and stabilizes the stump remover as it is
manually moved by the operator across the stump, the stump thereby being
cut away and ground down to the cutting depth as the stump remover
traverses the stump. If the base element is located on one side of the
rotating cutting teeth, the stump remover could be manually moved across
the stump by the operator in the direction which permits the lower base
surface to precede the rotating cutting teeth and ride on the top of the
stump.
The amount by which the cutting teeth project below the lower base surface
may be made adjustable to vary the cutting depth, depending upon the type
of tree stump (hard or soft wood and the stump size) being removed.
Appropriate handles may also be provided for hand holding and guiding the
stump remover across the tree stump. Moreover, for safety reasons the
cutting device may be shrouded to protect the operator not only from
contact with the rotating cutting teeth but also from the flying wood
debris, such as wood chips and sawdust, produced during the stump cutting
process.
Claims
I claim:
1. A portable, self-contained stump remover which is manually movable by an
operator across a tree stump to effect grinding thereof, comprising;
a base element having a lower base surface for engaging and resting on the
top of the tree stump when the stump remover is placed on the stump;
at least one rotatable cutting device having a plurality of cutting teeth;
and driving means for rotating said cutting device to rotate said cutting
teeth through a circular path at least a portion of which path extends
below said lower base surface, a cutting depth being defined by the extent
to which the rotating cutting teeth project below the base surface,
the lower base surface engaging the tree stump and supporting, guiding and
stabilizing the stump remover as the stump remover is manually moved by
the operator across the stump, the stump thereby being cut away and ground
down to the cutting depth as the stump remover traverses the stump.
2. A stump remover according to claim 1 wherein the stump remover may be
hand held by the operator as it is moved across the stump.
3. A stump remover according to claim 1 and including a pair of handles to
facilitate manual holding and guiding of the stump remover as it is moved
across the stump.
4. A stump remover according to claim 1 wherein said cutting device is
adjustably attached to said base element in order to facilitate adjustment
of the cutting depth.
5. A stump remover according to claim 1 and including a dead man's switch
for manually controlling the operation of said driving means.
6. A stump remover according to claim 1 wherein said driving means includes
a motor having a rotating output shaft couples to said cutting device to
effect rotation thereof.
7. A stump remover according to claim 6 wherein said cutting device is
mounted on and secured to said output shaft so as to be driven directly by
said motor.
8. A stump remover according to claim 1 wherein said driving means includes
a gasoline internal-combustion engine.
9. A stump remover according to claim 1 wherein said cutting device
includes a cutting wheel having a series of cutting teeth around its
circular periphery.
10. A stump remover according to claim 1 wherein said lower base surface is
on one side of said cutting teeth, cutting of the stump down to the
cutting depth being achieved when the stump remover is manually moved
across the stump by the operator in the direction which permits the base
surface to precede the rotating cutting teeth and ride on the top of the
stump.
11. A stump remover according to claim 1 wherein said lower base surface
provides a planar surface for interfacing with the surface of the stump in
order to enhance the stability of the stump remover as it grinds the
stump.
12. A stump remover according to claim 1 wherein said lower base surface is
a flat surface that conforms to a flat surface of the stump.
13. A stump remover according to claim 1 wherein said base element is a
flat base plate that extends across a substantial portion of the stump
remover.
14. A stump remover according to claim 1 wherein said cutting teeth are
removably secured to said cutting device to facilitate replacement of the
teeth.
15. A stump remover according to claim 1 wherein the rotating cutting teeth
follow the moving base element, when the stump remover traverses the
stump, to mill away the stump down to the cutting depth.
16. A stump remover according to claim 1 and including means for varying
the amount by which said cutting teeth project below said lower base
surface, thereby permitting adjustment of the cutting depth.
17. A stump remover according to claim 1 wherein the circular path through
which said cutting teeth rotate is effectively fixed relative to said
driving means, and wherein said driving means is mounted on said base
element by means of a bracket arrangement that may be adjusted to vary the
distance bwtween the driving means, and thus the cutting teeth, and the
lower base surface, thereby to adjust the cutting depth.
18. A stump remover according to claim 1 and including a shroud around said
cutting device to provide a guard over the cutting device and a protective
shield against flying wood debris, created during the stump cutting
process, that may otherwise injure the operator of the stump remover.
19. A stump remover according to claim 18 wherein said shroud has one
portion which covers and encloses substantially all of said cutting device
but has a downwardly extending open end through which said cutting teeth
may project downward to engage and grind the stump, and wherein said
shroud has another portion which is pivotally connected to and normally
encloses and guards the open end of said one portion to completely envelop
said cutting device, said other portion thereby normally extending below
both said cutting teeth and said lower base surface, and wherein said
other portion engages the tree stump and is pivoted and camed by the stump
out from under the cutting teeth as the operator moves the stump remover
across the stump, thereby permitting the cutting teeth to cut the stump.
20. A stump remover according to claim 18 wherein said shroud has an
opening through which the flying wood debris may exit from the shroud, and
including a debris flap connected to the outside of the shroud and
normally covering the opening, said flap being pushed out by the force of
the flying wood debris to uncover the opening during the cutting process
to allow the debris to escape from the shroud.
21. A stump remover according to claim 20 and including a debris guide
within said shroud to guide the flying wood debris to said opening.
22. A stump remover according to claim 21 wherein said debris guide has a
pair of guide tracks to provide a channel-shaped guide leading to said
opening.
23. A stump remover according to claim 21 wherein said debris guide
includes two non-parallel, converging guide tracks that effectively funnel
the flying wood debris to said opening.
24. A stump remover according to claim 1 and including a shroud surrounding
said cutting device, and in a fixed position relative to said base
element, to provide a guard over the cutting device and a protective
shield against flying wood debris created during the stump cutting
process, and biasing means for normally retracting said cutting device
upwards and further into said shroud to the extent that the lowermost
projections of the cutting teeth are positioned above said lower base
surface, said biasing means being operable by the operator of the stump
remover to effect lowering of the cutting device so that the cutting teeth
will extend below the lower base surface in order to effect grinding of
the tree stump.
25. A stump remover according to claim 24 wherein said biasing means
includes at least one spring for spring mounting said driveing means on
said base element and normally biasing said driving means and said cutting
device upwards in a direction away from the base element, and wherein the
biasing force of said spring may be overcome by the operator by pushing
down on the driving means, thereby causing the cutting teeth to extend
below the lower base surface.
26. A stump remover according to claim 25 wherein the spring mounting
arrangement between said driving means and said base element guides the
movement of said cutting device, as it is retracted further into said
shroud when the operator releases downward pressure on the driving means,
so that the cutting device moves in an angular direction both upwards and
sideways in order to maximize the separation from the base element.
27. A stump remover according to claim 25 and including a lever, attached
to said driving means, which may be depressed by the operator to
facilitate pushing down of the driving means.
28. A stump remover according to claim 1 wherein said driving means is
adjustably attached to said base element in order to facilitate adjustment
of the cutting depth.
29. A stump remover according to claim 1 wherein said driving means is
pivotally interconnected to said base element to permit varying of the
position of said cutting device relative to the lower base surface to
adjust the cutting depth to a selected setting in a predetermined range,
and including locking means for locking the interconnection between the
driving means and the base element to hold the cutting depth at the
selected setting.
30. A stump remover according to claim 1 and including a shroud covering
and surrounding said cutting device to provide a guard over the cutting
device and a protective shield against flying wood debris, said shroud
having a downwardly extending open end through which said cutting teeth
may project downward in order to engage and grind the stump, and wherein
the position of said shroud, relative to the position of the cutting
device, is adjustable by the operator to vary the extent to which the
cutting teeth project down through the shroud's open end.
31. A stump remover according to claim 30 and including biasing means for
normally biasing said shroud in its position providing maximum coverage
and enclosure of said cutting device.
32. A stump remover according to claim 31 wherein the positions of said
driving means and said cutting device are fixed relative to each other,
and wherein said shroud is attached to said driving means by a flexible
spring bracket which may be flexed by the operator to raise the shroud and
increase the amount by which said cutting teeth extend down through the
shroud's open end.
33. A stump remover according to claim 32 and including a lever, attached
to said shroud, which may be depressed by the operator to bend said
flexible spring bracket to raise the shroud, release of the pressure by
the operator causing the shroud to lower to increase the enclosure around
said cutting teeth.
34. A stump remover according to claim 1 and including a shroud covering
and substantially enclosing said cutting device to provide a guard over
the cutting device and a protective shield against flying wood debris,
said shroud having a downwardly extending open end through which said
cutting teeth may project downward in order to engage and grind the tree
stump, and wherein an edge portion of the open end of said shroud also
functions as and constitutes said base element, the lower surface of said
edge portion thereby engaging the tree stump, and supporting, guiding and
stabilizing the stump remover, as the operator manually moves the stump
remover across the stump, the cutting depth being determined by the
distance that the cutting teeth extend below the lower surface of said
edge portion.
35. A stump remover according to claim 34 wherein the positions of said
driving means and said cutting device are fixed relative to each other,
while the position of said shroud is adjustable relative to said driving
means in order to vary the extent to which the cutting teeth project below
the lower surface of said edge portion, thereby to facilitate adjustment
of the cutting depth.
36. A stump remover according to claim 35 wherein said shroud is fastened
to said driving means by an adjustable bracket arrangement which permits
the shroud to be vertically adjusted to, and locked in, a selected
vertical position relative to the driving means.
37. A stump remover according to claim 1 wherein the plane, defined by said
circular path through which said cutting teeth rotate, is generally
perpendicular to the direction in which the operator moves the stump
remover across the tree stump.
38. A stump remover according to claim 37 wherein the stump remover is
usually moved across the tree stump by the operator in a generally
horizontal direction, the plane defined by said circular path thereby
being generally vertical with the stump being cut by the rotating cutting
teeth as they rotate through the lowermost portion of the circular path,
which portion lies below said lower base surface.
39. A stump remover according to claim 1 wherein the plane, defined by said
circular path through which said cutting teeth rotate, is generally
parallel to the direction in which the operator moves the stump remover
across the tree stump, the entire circular path thereby lying below said
lower base surface to effect cutting of the stump.
40. A stump remover according to claim 1 and including a plurality of
rotatable cutting devices simultaneously rotated by said driving means and
each device having a plurality of cutting teeth that rotate through a
different circular path.
41. A stump remover according to claim 40 wherein the rotational axes of
said cutting devices are parallel to each other, and wherein the different
circular paths lie in the same plane and are below said lower base
surface.
42. A stump remover according to claim 41 wherein there is an even number
of said cutting devices, and wherein half of the cutting devices are
rotated in one direction while the other half are rotated in the opposite
direction in order to balance the opposing torques produced by the cutting
devices.
43. A stump remover according to claim 41 wherein each of said cutting
devices includes a generally vertical, cylindrical shaped body which
rotates around the body's longitudiual axis, the cutting device's teeth
being attached to the body's lowermost end.
Description
DESCRIPTION OF THE DRAWINGS
The features of the invention which are believed to be novel are set forth
with particularity in the appended claims. The invention may best be
understood, however, by reference to the following description in
conjunction with the accompanying drawings in which like reference numbers
identify like elements, and in which:
FIG. 1 is a side view of a tree stump remover constructed in accordance
with one embodiment of the invention;
FIGS. 2 and 3 are top and end views respectively of the stump remover of
FIG. 1;
FIG. 4 is a sectional view of the stump remover taken along line 4--4 in
FIG. 1;
FIG. 5 is a fragmentary, exploded, perspective view of a portion of the
stump remover of FIG. 1 and shows the manner in which a cutting tooth may
be removably affixed to a cutting device to facilitate replacement of the
tooth;
FIG. 6 is a fragmentary, side view, partly in section, of a portion of the
stump remover of FIG. 1 and illustrates the manner in which the rotating
cutting teeth cut into and remove a tree stump;
FIGS. 7 and 7a illustrate the manner in which the stump remover of FIGS.
1-6 may be modified in accordance with another embodiment of the invention
to provide means for permitting adjustment of the cutting depth, and also
to provide a shroud around the cutting device, the cutting device normally
being retracted upwards by a spring bias into the shroud (shown in FIG. 7)
so that the cutting teeth do not project below the lower base surface, but
are capable of being lowered by the operator, against the force of the
spring bias, in order to extend the teeth below the base surface (shown in
FIG. 7a) to effect grinding of a tree stump;
FIGS. 8 and 8a show another modification of the stump remover of FIGS. 1-6
in which the cutting depth is variable and wherein the position of a
shroud is adjustable to vary the extent to which the rotating cutting
teeth are enclosed by the shroud, FIG. 8 illustrating the shroud
completely covering and surrounding the cutting teeth and the teeth being
above the lower base surface to provide a zero cutting depth, while FIG.
8a shows a maximum cutting depth with the shroud being positioned to
maximize the exposure of the cutting teeth out of the shroud;
FIG. 9 is a side view of a tree stump remover constructed in accordance
with another embodiment of the invention and illustates that the shroud
around the cutting teeth may have a pivotally connected guard that
normally covers the cutting teeth which extend below the lower base
surface and is pivoted and camed by the tree stump out from under the
cutting teeth as the operator moves the stump remover across the stump;
FIG. 10 is a fragmentary side view and FIG. 11 is an end view showing a
modification of the stump remover of FIG. 9, wherein the shroud is
provided with an internal channel-shaped debris guide to lead the flying
wood debris to a flap-covered opening through which the debris may exit
the shroud;
FIG. 12 illustrates a stump remover similar to that shown in FIGS. 9, 10
and 11 and shows that the debris guide, within the shroud, may take the
form of two non-parallel, converging guide tracks that effectively funnel
the flying wood debris to the opening in the shroud;
FIG. 13 is a fragmentary side view showing a modification of the stump
remover of FIG. 1 and includes a vertically adjustable shroud a lower edge
portion of which shroud serves as the base element, and provides the lower
base surface, so that adjusting the shroud varies not only the extent to
which the cutting teeth are enclosed by the shroud but also the cutting
depth;
FIGS. 14 and 15 are bottom and side views respectively of another
embodiment wherein a pair of oppositely rotating cutting devices each has
a plurality of cutting teeth that rotate through a circular path whose
plane is 90 degrees displaced from the plane defined by the circular path
followed by the cutting teeth in the previous embodiments, the entire
circular paths of the teeth in the FIGS. 14 and 15 embodiment therefore
liying below the lower base surface to effect cutting of a stump;
FIG. 16 is a fragmentary, exploded, perspective view of a portion of the
stump remover of FIGS. 14 and 15 and illustrates the manner in which the
cutting teeth of each cutting device may be removably secured to the
device;
and FIG. 17 shows a variation of the embodiment of FIGS. 14, 15 and 16
wherein four cutting devices are employed, two of which rotate in one
direction while the other two rotate in the opposite direction to balance
the opposing torques.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the embodiment of FIGS. 1-6, a rectangular-shaped plastic
support frame is provided by the two long parallel plastic tubes 11 and 12
and the three shorter plastic tubes 13, 14 and 15 that attach to and
interconnect the tubes 11 and 12. Secured to the bottom of the plastic
frame is a rectangular-shaped plastic base plate or element 17 which is
preferably affixed to the three tubes 13, 14 and 15 by means of a series
of six carriage bolts 18 and appropriate nuts, the nuts being inside of
the tubes, as best seen in FIG. 4. Only four of the six carriage bolts 18
are visible in FIGS. 1-6. The bottom surface 17a of base plate 17 provides
a lower base surface.
A small gasoline internal-combustion engine or motor 21 is secured by bolts
22 (see FIG. 4) and appropriate nuts (not shown) to an L-shaped metal
bracket 23 which in turn is affixed by bolts 24 and appropriate nuts (see
FIG. 4) to tubes 11 and 12. An L-shaped plastic tube 26 has one end bolted
(by bolt 27) to the housing 28 of gasoline engine 21 and the other end
rigidly secured to tube 15. A gasoline tank 29, strapped to and held by
tube 26, is coupled by fuel line 31 through an on/off fuel line valve 32
to the carburetor 33 of engine 21.
A dead man's switch 34 is mounted on tube 26 for manually controlling the
operation of engine 21. Tube 26 also serves as a handle to be held by the
operator's right hand. The portion of tube 26 to be grasped by the
operator's right hand is covered by a cushion sleeve 35 for ease of
handling. A handle for the operator's left hand is provided by a metal bar
37, one end of which is affixed by the two bolts 38 to bracket 23 while
its other end is secured to the inside of a plastic tube over which is
provided a cushion sleeve 39. The engine or motor 21 includes a pull start
41, a single spark plug 42 and an exhaust pipe 43 and operates in
conventional fashion in order to rotate its output shaft 44 anytime switch
34 is held closed by the operator.
A rotatable cutting device 46 is mounted on and secured to output shaft 44
so as to be driven directly by engine 21. More specifically, device 46
includes a circular disc or wheel 47 which is affixed to hub 48 by means
of bolts 49 (see FIG. 6) and nuts 52, the hub being secured to shaft 44 by
bolt 53. Cutting device 46 has a series of eight cutting teeth 55 evenly
spaced around its circular periphery and projecting beyond or outside of
the circumference of disc 47. Preferably, these teeth are removably
secured to the cutting device to facilitate easy replacement when the
teeth are worn out. This is best illustrated in FIG. 5 where it is seen
that each tooth 55 is attached to the periphery of wheel 47 by means of
two bolts 56, four washers 57, two lock washers 58 and two nuts 59. When
driven by engine 21, cutting device 46 rotates in a counter-clockwise
direction as viewed in FIG. 3 and as indicated by the arrow 61 in the
figure. The leading surfaces of the radially outermost ends or tips of the
rotating teeth 55 are provided with a carbide coating 55a since, as will
be seen, those are the surfaces that will engage and cut a tree stump.
As is apparent, the circular path, through which the cutting teeth 55
rotate, defines a plane which is perpendicular to the planar, lower base
surface 17a provided by the base plate 17. A portion of this path extends
below the lower base surface 17a, the cutting depth of the stump remover
being determined by the extent to which the rotating cutting teeth 55
project below the base surface 17a. In operation, after pull start 41 and
switch 34 are actuated to start engine 21 and effect rotation of cutting
device 46. The operator grasps cushion sleeve 35 with his right hand and
cushion sleeve 39 with his left hand and lifts the stump remover and
places the lower base surface 17a on top of a tree stump to be removed so
that the cutting device is positioned next to, but does not contact, the
tree stump. The operator then manually moves, specifically pulls or drags,
the stump remover across the stump, preferably in a generally linear
direction along the longitudinal axis of base plate 17 (namely to the
right as viewed in FIGS. 1, 2 and 6), so that the base surface 17a
precedes the rotating cutting teeth 55 and rides on top of the stump, the
cutting teeth thereby cutting the stump away and grinding or milling it
down to the cutting depth. This is clearly evident in FIG. 6 which
illustrates a tree stump 63 being cut by the cutting teeth. Of course, the
operator must traverse the stump repeatedly to completely remove the stump
down to or below the ground level. Depending on the size of the tree stump
and the type of tree, several passes across the stump will probably be
necessary since each pass removes only a portion of the stump down to the
cutting depth as shown in FIG. 6. The stump remover is capable of cutting
and grinding a stump to a level substantially below the ground or grade
level and well into the stump's roots.
It is to be appreciated that when base plate 17 is placed on and engages a
tree stump, the base surface 17a functions to support, guide and stabilize
the stump remover as it is manually moved by the operator across the
stump. With the base plate providing a planar or flat lower base surface
of substantial size to interface with the top surface of the stump, the
stability of the stump remover is significantly enhanced. It is to be
noted, however, that by sacrificing some stability the function performed
by base plate 17 and base surface 17a may be performed by any of a wide
variety of different structures having different sizes and shapes. For
example, base plate 17 may comprise merely a narrow bar or strip or even a
rod. All that is necessary is to provide some reference or base surface
that will ride on top of the stump, and below which base surface the
rotating cutting teeth project, as the stump remover is moved across the
stump. The position of the base surface relative to the lowermost portion
of the circular cutting path of the rotating cutting teeth, namely the
distance or separation between that base surface and the lowermost portion
of the cutting path, defines the cutting depth of the stump remover. Since
many different devices or elements may be employed to provide such a base
surface, some of the appended claims merely recite "a base element having
a lower base surface".
While the output shaft 44 of the driving means, namely gasoline engine 21,
is directly connected to the cutting device 46, it will be understood that
the coupling between the driving means and the cutting device may be
indirect and may comprise any appropriate drive, such as belt, gear,
fluid, etc. If desired, the coupling may be adjustable or the driving
means may be adjustable to vary the speed of the cutting device. In
addition, it may be desirable to include a slipping means of some type or
an automatically releaseable clutch in the coupling so that the driving
connection from the driving means will be effectively interrupted if the
cutting device becomes hung up or stuck, thereby minimizing the
possibility of burning out the driving means.
In the embodiment shown in FIGS. 1-6, the positions of the driving means
(engine 21), the circular cutting path through which the cutting teeth 55
rotate, and the base element 17 and its lower base surface 17a are all
effectively fixed relative to each other, the cutting depth of the stump
remover thereby also being fixed. In the embodiment of FIGS. 7 and 7a,
which is a modification of the FIGS. 1-6 embodiment, the position of the
driving means and the circular cutting path are fixed relative to each
other, but their positions are variable relative to that of the lower base
surface to facilitate adjustment of the cutting depth. An adjustable
cutting depth is desirable for cutting different types of tree stumps. In
effect, the driving means is adjustably attached to the base element to
permit adjustment of the cutting depth. This is achieved in the embodiment
of FIGS. 7 and 7a by means of a bracket arrangement 66 that may be
adjusted to vary the distance between the driving means 21, and thus the
cutting teeth 55, and the lower base surface 17a of base element or plate
17.
To elucidate, a bracket plate 67, affixed to plastic tubes 11-15 and base
plate 17, has a vertical slot 67a for accomodating a bolt 68 which is
screwed into the housing 28 of engine 21. Plate 67 also has a pair of
angular slots 67b through which a pair of studs 69 extend, the studs being
rigidly secured to housing 28. A pair of coil springs 71 are mounted
between engine 21 and the base structure formed by tubes 11-15 and base
element 17. A shroud 73, affixed to tubes 11 and 12, surrounds cutting
device 46 to provide a guard over the cutting device and a protective
shield against flying wood debris, created during the stump cutting
process, that may otherwise injure the operator of the stump remover.
Shroud 73 has a downwardly extending open end through which the cutting
teeth 55 may project in order to engage and grind a tree stump. When bolt
68 is loose and not tightly screwed into engine housing 28, engine 21 is
positioned as shown in FIG. 7 and is spring mounted on tubes 11-15 and
base element 17, the coil springs 71, which serve as a biasing means,
normally biasing or urging engine 21 and cutting device 46 upwards in a
direction away from base element 17. In that FIG. 7 position of engine 21,
cutting device 46 is retracted upwards into shroud 73 to the extent that
the lowermost projections of the cutting teeth 55 are positioned above the
lower base surface 17a, thereby providing a zero cutting depth.
If it is desired to adjust the cutting depth to a particular selected level
and to maintain the depth fixed at that level, engine 21 may be pushed
down by the operator against the biasing force of springs 71 until the
cutting teeth extend below base surface 17a the desired amount. When that
selected cutting depth is reached, bolt 68 is tightened securely so that
bracket plate 67 will be fixed to housing 28 and the selected cutting
depth will be locked in. FIG. 7a shows the stump remover when it is locked
in at the maximum cutting depth. A bar 74, which is secured to engine
housing 28 by bolt 75, provides a lever which may be depressed by the
operator to facilitate pushing down of engine 21. As the engine is pushed
down from its uppermost position shown in FIG. 7 to its lowermost position
shown in FIG. 7a, bracket plate 67 and everything affixed thereto (namely,
tubes 11-15, base element 17, base surface 17a and shroud 73) will remain
stationary while engine 21 and cutting device 46 move both vertically and
slightly sideways to the right due to the guiding effect of angular slots
67b and studs 69, the studs being camed and shifted to the right as they
are pushed down to the bottom of slots 67b. The desirability of the
lateral shifting of engine 21 and cutting device 46 will be appreciated
later. Of course, since bolt 68 is also moving sideways to the right, as
well as vertically down the slot 67a, as engine 21 is lowered, the
diameter of the shaft of bolt 68 should be sufficiently smaller than the
width of vertical slot 67a so that the slot will not interfere with the
lateral movement of engine 21 and cutting device 46.
If it is not necessary to lock the stump remover at a particular desired
cutting depth, bolt 68 may be loosened so that the spring action provided
by coil springs 71 will automatically raise engine 21 and retract the
cutting device 46 further into shroud 73, as shown in FIG. 7. In this way,
until actual cutting of a stump is desired, no pressure is exerted by the
operator on lever 74, thereby causing springs 71 to hold the stump remover
in its FIG. 7 position so that the cutting teeth 55 will not project below
base surface 17a. In this position, the protection afforded by shroud 73
is maximized. When stump cutting is desired, the operator merely depresses
lever 74 to overcome the biasing force of springs 71 and lower the cutting
teeth 55 to the extent desired. Of course, if the pressure on lever 74 is
sufficient to push engine 21 down to its position shown in FIG. 7a, the
maximum cutting depth is achieved. When it is desired to cease cutting,
the operator releases the downward pressure on lever 74, and consequently
on engine 21, whereupon springs 71 cause the cutting device 46 to retract
further into shroud 73 as shown in FIG. 7. The advantage of angular slots
67b and studs 69 will now be appreciated. As engine 21 and cutting device
46 are raised, relative to base surface 17a, in going from their positions
illustrated in FIG. 7a to their positions illustrated in FIG. 7, the
cutting device moves laterally to the left. In other words, under the
guidance of angular slots 67b and studs 69, cutting device 46 moves in an
angular direction both upwards and sideways to the left. This maximizes
the separation of the cutting device from base surface 17 a, which will be
helpful in freeing the cutting device if it ever gets hung up or stuck in
a stump being cut.
The embodiment of FIGS. 8 and 8a illustrates another arrangement for
providing an adjustable engine mount to obtain a variable cutting depth
that may be locked in at a desired setting. Engine 21 is pivotally
connected, by means of hinge 78, to the base structure comprising tubes
11-15, base element 17 and base surface 17a. The position of engine 21,
and consequently that of cutting device 46, relative to the position of
base surface 17a may therefore be adjusted to establish the cutting depth
at any desired setting over a predetermined range, and that setting may be
locked in by means of bracket plate 79 which is affixed to tube 11 and has
a slot 79a through which bolt 81 extends and screws into engine housing
28. In FIG. 8, hinge 78 is locked in its position providing a minimum,
actually zero, cutting depth, while in FIG. 8a the hinge is adjusted to
and locked in its maximum cutting depth position.
This embodiment also includes a shroud 82 covering and surrounding the
cutting device 46 and whose position, relative to that of the cutting
device, is adjustable by the operator to vary the extent to which the
cutting teeth 55 project down through the shroud's open end. Portion 82a
of the shroud is affixed to tubes 11 and 12, whereas the remaining and
major portion of shroud 82 is attached to the engine housing 28 by means
of a flexible spring bracket 83 that may be flexed by the operator to
raise the shroud and increase the amount by which the cutting teeth 55
extend down through the shroud's open end. In effect, spring bracket 83
serves as a biasing means for normally biasing or urging shroud 82 in its
position providing maximum coverage and enclosure of cutting device 46.
Lever or bar 84, attached to shroud 82 by bolt 85, may be depressed by the
operator to bend the flexible spring bracket 83 to raise the shroud,
release of the pressure by the operator causing the shroud to lower,
thereby increasing the enclosure around the cutting teeth 55.
The embodiment of FIG. 9 is similar to that of FIGS. 7 and 7a and includes
a shroud 88, a major portion 88a of which is affixed to tubes 11 and 12
and encloses substantially all of the cutting device 46, portion 88a
having a downwardly extending open end through which the cutting teeth 55
may project downward to engage and grind a tree stump. Shroud 88 has
another, smaller portion 88b which is pivotally connected, by a pair of
pivot pins 87 (only one of which is shown in FIG. 9), to and normally
encloses and guards the open end of shroud portion 88a to completely
envelop cutting device 46. Portion 88b is shown in its normal position in
FIG. 9 and in that position extends below both the cutting teeth 55 and
lower base surface 17a. When the operator pulls the stump remover across a
stump, portion 88b of the shroud engages the stump and is pivoted and
camed by the stump out from under the cutting teeth 55, thereby permitting
the cutting teeth to cut the stump.
The FIG. 9 embodiment may be modified to provide the embodiment of FIGS. 10
and 11 wherein a similar shroud 89 has a major fixed portion 89a and a
minor movable portion 89b which is pivotally connected to portion 89a, by
a pair of pivot pins 91, so that it may be camed or kicked out of the way
by a tree stump to allow the cutting teeth to cut the stump. Shroud 89
differs from shroud 88 in having an opening 89c (seen in FIG. 11) in
portion 89a, through which opening the flying wood debris may exit from
the shroud. A flexible debris flap 92 is connected along one of its edges
to the outside of the shroud by screws 93 and normally covers the opening
89c, the flap 92 being pushed or flexed out during the cutting process by
the force of the flying wood debris to uncover the opening and allow the
debris to escape from the shroud. The inside of shroud portion 89a also
has a channel-shaped debris guide 94 having a pair of depending, parallel
guide tracks for leading or guiding the flying wood debris to opening 89c.
In the embodiment of FIG. 12, the debris guide has two non-parallel guide
tracks 95, on the inside of shroud 96, that converge toward and lead to an
opening 96a in the shroud in order to effectively funnel the flying wood
debris to the opening.
As mentioned previously, the base element that provides a lower base
surface for riding or resting on top of a tree stump may take a variety of
different forms. In the FIG. 13 embodiment, a portion of a vertically
adjustable shroud may serve as the base element. In that figure, a metal
bracket 99 is secured to both engine 21 and plastic tube 11 to provide a
stationary engine mount. Shroud 101 is fastened to engine 21 by an
adjustable bracket arrangement which permits the shroud to be vertically
adjusted to, and locked in, a selected vertical position relative to
engine 21 and consequently to cutting device 46. Specifically, a pair of
brackets 102 are affixed to shroud 101, while a pair of bolts 103, each of
which extends through a slot of one of brackets 102, screw into either the
housing 28 of engine 21 or into bracket 104 which is bolted to bracket 99.
Note that shroud 101 is not secured to plastic tube 11, but is adjustable
with respect thereto. Moreover, a plastic plate equivalent to plate 17 is
not needed between tubes 11 and 12. Note also that as shroud 101 is
vertically adjusted relative to cutting device 46, an edge or rim portion
101a of the downwardly extending open end of the shroud (through which
open end the cutting teeth 55 may engage and cut a tree stump) also moves
vertically and provides a lower base surface that rides on top of and
engages the stump when the stump remover is placed on the stump, as is
evident in FIG. 13. Edge portion 101a therefore functions as and
constitutes the base element, providing a lower base surface that engages
the tree stump and supports, guides and stabillizes the stump remover as
it is moved across the stump by the operator. Hence, when the vertical
position of shroud 101 is changed, relative to the position of cutting
device 46, the extent to which the cutting teeth 55 are covered and
enclosed by the shroud is changed, as well as the cutting depth, namely
the extent to which the cutting teeth project below the lower surface of
edge portion 101a. As shown in FIG. 13, shroud 101 is locked in its
uppermost position, thereby minimizing the enclosure of cutting teeth 55
by the shroud and maximizing the cutting depth. Tab 105 is affixed to
shroud 101 and may be grasped by the operator to facilitate vertical
adjustment of the shroud and setting of the cutting depth at a desired
level.
In the embodiments of FIGS. 1-13, the plane, defined by the circular path
through which the cutting teeth rotate, is generally vertical and is
perpendicular to the generally horizontal direction in which the operator
usually moves the stump remover across a tree stump during the cutting
process. With the plane of the circular path being vertical, the stump is
cut by the rotating cutting teeth only as they rotate through the
lowermost portion of the circular path, namely the portion of the path
that extends or lies below the lower base surface. In the embodiment of
FIGS. 14-16, there are also cutting teeth that rotate in a circular path,
but the plane of this path is generally horizontal and parallel to the
direction in which the operator pulls the stump remover across a tree
stump to effect cutting thereof. In this case, the entire circular path of
the cutting teeth lie below the lower base surface when the stump is cut.
More particularly, in the embodiment of FIGS. 14-16 a support frame is
provided by a pair of parallel plastic tubes 107 and 108 that are
interconnected by a plastic tube 109. The base element takes the form of a
plastic bar 112 which is bolted to tube 109, the bottom surface 112a of
the base element thereby providing the lower base surface. Although the
complete driving means is not shown, it is to be understood that it may
comprise an internal combustion gasoline engine which is oriented 90
degrees from its orientation in the previous embodiments so that the
engine's output shaft 113 will be vertical and will extend downwardly. A
drive gear 114 is secured to shaft 113 and will rotate with the shaft in
the direction indicated by the associated arrow in FIG. 14 when the engine
is operating. Instead of having only one cutting device rotated by engine
shaft 113, two (115 and 116) are simultaneously rotated with each cutting
device having a plurality of cutting teeth. Cutting device 115 comprises a
vertical, cylindrical shaped body 117 rotatably mounted within a bearing
118 which is bolted to tube 107, whereas cutting device 116 has a similar
vertical, cylindrical shaped body 119 rotatably mounted within a bearing
121 secured to tube 108. A driven gear 122, secured to the upper end of
body 117, engages and is driven by drive gear 114 to effect rotation of
body 117 around the body's longitudinal axis and in the direction
indicated by the associated arrow in FIG. 14. Body 119 also has a driven
gear 123 affixed to its upper end, but this gear meshes with and is driven
by gear 122 so that body 119 will rotate in the direction opposite to that
of body 117.
Each body 117, 119 has a pair of cutting teeth 125 removably attached to
the body's lowermost end to facilitate replacement of the teeth when they
are worn out. This is best seen in FIG. 16 which illustrates, by way of
example, the manner in which the cutting teeth 125 are affixed to body 117
of cutting device 115. Body 117 has a pair of pockets or openings 117a for
receiving the upper ends of the cutting teeth. Set screws 126 are provided
to retain the cutting teeth 125 in their respective pockets.
It is apparent that when the engine is operating, shaft 113 causes the
cutting teeth 125 of each cutting device 115, 116 to rotate through
different circular paths, both of which paths lie in the same horizontal
plane and entirely below the lower base surface 112a. Hence, if the
operator places the stump remover of FIGS. 14-16 on top of a tree stump,
base surface 112a will rest on and engage the stump. By moving the stump
remover across the stump in the direction in which base surface 112a will
lead or be ahead of the rotating cutting teeth 125, the stump will be cut
away and ground down to the cutting depth determined by the distance that
cutting teeth 125 project below base surface 112a. Of course, rotating the
cutting devices 115, 116 in opposite directions balances or neutralizes
the opposing torques produced by the cutting devices.
Obviously, the invention may also be implemented by employing more than two
simultaneously rotating cutting devices. In the FIG. 17 embodiment, the
vertical and downwardly extending output shaft 113 of the engine rotates a
gear 127 which drives the gear train comprising the four gears 128, 129,
131 and 132, each of gears 128-132 in turn rotating associated cutting
devices (not shown) similar to that shown in FIGS. 14-16. As indicated by
the arrows in FIG. 17, the two cutting devices rotated by gears 128 and
131 rotate in one direction, while the other two cutting devices rotated
by gears 129 and 132 rotate in the opposite direction to balance the
opposing torques of the cutting devices. Preferably, when more than two
cutting devices are employed, an even number should be selected in order
to facilitate neutralization of the torques developed.
While particular embodiments of the invention have been shown and
described, modifications may be made, and it is intended in the appended
claims to cover all such modifications as may fall within the true spirit
and scope of the invention.
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