Note: Descriptions are shown in the official language in which they were submitted.
~27~7500
SLOPE MOWER WITH SIDE FRAMES
Backyround of the Invention
This invention relates to mowing vehicles in general
and particularly to such vehicles that are responsive to
changes in terrain such that the vehicle body is maintained
in a generally vertical orientation.
Mowing vehicles, such as riding lawn mowers and
tractors with mowing attachments, have long been used in
mowing hillsides, particularly by highway maintenance
personnel. Most of these vehicles do not provide means for
adapting to changing terrain, such that when a vehicle is on
a slope the frame tilts accordingly, which can result in the
vehicle tipping over. At the least, there is a dangerous
situation, with operators sometimes leaning their bodies
toward the upside of the hill in an effort to lower the
center of gravity. Prior vehicles have often been
adaptations of existing machines involving mechanical
actuation of a mower blade assembly to conform to the slope,
without significant modification of the vehicle frame such
that the frame tilts with the slope. Such embodiments are
limited in the deyree of slope upon which they can be
effectively and safely operated. Other devices have
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involved three- or four-wheeled vehicle frames with complex
actuation of fixed deck blade housings.
Additionally, these complex machines have been
expensive, which prohibits many small operators and
municipalities from using them. The saftey advantages of
providing an arrangement whereby the operator always sits
vertically even though he is mowing along a sloped
embankment are obvious. Heretofore, there has not been a
slope mower having a relatively simple leveling system for
maintaining the vehicle frame in a vertical orientation, nor
has there been such a vehicle having a blade housing
arrangement for adapting to variances in the slope of the
ground covered by the path of the mower.
Objects of the Invention
The principal objects of the present invention are: to
provide a mower vehicle for mowing sloping hillsides; to
provide such a vehicle which has means to maintain the
vehicle frame and accordingly, the operator, in a generally
vertical or upright orientation; to provide such a vehicle
which includes a single front and a single rear wheel; to
provide such a vehicle having means for driving each of the
front and rear wheels; to provide such a vehicle which has
dual blade housings centered on an axis extending
longitudinally of the frame and pivota~ly connected thereto;
to provide such a vehicle which has hydraulic assemblies for
pivoting the blade housings independently of one another; to
provide such a mower vehicle which has a leveling
arrangement for actuating the hydraulic cylinder arrangement
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to maintain each blade housing in operative contact with the
ground while maintaining the vehicle frame in a generally
vertical orientation to provide such a vehicle having a
hydraulic cylinder arrangement connected to an accumulator
device for permitting the blade housings to operate
independently of one another; to provide such a vehicle
including wheeled side frames pivotally attached to opposite
sides of the vehicle and hydraulically biased to maintain
such vehicle in an upright orientation and having mower
housings floating relative to each side frame; to provide
such a vehicle which is relatively simple to use, economical
to manufacture, and particularly well adapted to the
proposed usage thereof.
According to the invention there is provided a mower
vehicle for mowing slopes comprising: a mower vehicle main
frame having a generally vertical orientation, when in
operation; single front wheel means and single rear wheel
means, each of said wheel means being connected to said main
frame and generally aligned such that said frame is pivotal
relative to the ground about a longitudinal line passing
through the bottom of both said front and rear wheel means;
a prime mover mounted on said main frame and connected to at
least one of said front wheel means and rear wheel means for
movement of said mower vehicle across the ground; a side
frame pivotally connected to said main frame and swingable
about an axis extending longitudinally of said main frame
said side frame extending laterally from said longitudinal
axis and having a ground engageable outrigger wheel
laterally spaced from said main frame; a mower housing
extending outwardly from said main frame and including
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cutting means mounted therein; said mower housing being
partially movable independent of said side frame; and
pivoting means for pivoting said side frame about said
longitudinal axis in automatic response to a change in
terrain thereby allowing said side frame to foll.ow the
terrain while said main frame pivots about the terrain on
said front and rear wheel means and remains in the vertical
orientation thereof.
Also according to the invention there is provided a
mower vehicle for mowing slopes comprising: a mower vehicle
main frame having a generally vertical upright orientation
when in operation and an operator seat adapted to receive an
operator; single front ground engaging wheel means and
single rear ground engaging wheel means, each of said wheel
means being connected to said main frame and generally
aligned such that said main frame and wheel means are
pivotal relative to the ground on a longitudinal axis
passing through a lower portion of both of said front and
rear ground engaging wheel means when said wheel means are
engaging the ground; a prime mover mounted on said main
frame and connected to at least one of said front wheel
means and rear wheel means for movement of said mower
vehicle across the ground; a side frame pivotally connected
to said main frame and swingable about an axis extending
longitudinally of said main frame; said side frame extending
laterally from said longitudinal axis and having a ground
engageable outrigger wheel laterally spaced from said main
frame a mower housing including cutting means mounted
generally beneath said side frame and pivotal on one side
thereof relative to said main frame; said mower housing
12~
including mobile support means spaced laterally from said
main frame said mower housing pivotally floating
independent of said side frame to allow independent movement
of said mower housing to follow ground terrain; pivoting
means operationally pivoting said side frame about said
longitudinal axis in response to a change in the angle of
the terrain relative to horizontal such that said side frame
follows the terrain and said main frame remains upright; and
level control means cooperating with said pivoting means to
maintain said main frame in the vertical orientation thereof
whereby when an operator is positioned in said operator
seat, the operator is maintained in an upright attitude even
when said vehicle passes over non-horizontal terrain.
Other objects and advantages of this invention will
become apparent from the following description taken in
conjunction with the accompanying drawings wherein are set
forth, by way of illustration and example, certain
embodiments of this invention.
Summary of the Invention
A slope mower includes a vehicle frame and, preferably,
single front and rear driven wheels. The vehicle is adapted
to maintain the frame in a generally upright orientation.
First and second blade housings are pivotally connected to a
central section of the frame and are swingable about
respective axes extending longitudinally of the frame, and
preferably, the blade housings rotate about a single,
central longitudinal axis. The first and second blade
housings extend laterally to opposite sides of the frame.
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Each blade housing carries a driven cutting blade, which
blades overlap slightly and rotate in synchronized reverse
_otations relative to one another. It is envisioned that
the blade housings can be modified to carry a reel type
cutting assembly. The blade housings are open to one
another and have a shared discharge passage at a center rear
section thereof. The reverse rotation of just two blades
with a central discharge has been found to be an efficient
cutting arrangement. A V-shaped divider is provided to
direct cut grass away from the path of the rear wheel. This
configuration also prevents substantial wind rows.
Hydraulic cylinder and piston rod arrangements are
provided to power rotate the first and second blade housings
about the central longitudinal axis in response to changes
in slope of the surrounding terrain. A leveling system is
provided for sensing changes in attitude of the vehicle
frame, and for actuating the hydraulic cylinder arrangments
to maintain the vehicle frame in a generally upright
position, which simultaneously results in the first and
second blade housings maintain contact with the ground.
In an alternative embodiment, a pair of side frames are
hinged to the vehicle frame with each of the side frames
being positioned by an hydraulic ram so as to maintain the
vehicle in an upright orientation. Each side member
includes an outrigger wheel for travel along the ground
surface. A pair of mower housings are floatably mounted
beneath respective side frames and hinged to the vehicle.
Each mower housing includes a height adjusting trailer wheel
on one end thereof and an antiscalping roller on the
opposite end. Each mower housing includes a pair of blades
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positioned such that all four blades of the device cut a
width appro~imately as wide as the device and, in
particular, between the two mower housings.
The drawings constitute a part of this specification
and include exemplary embodiments of the present invention
and illustrate various objects and features thereof.
Brief Description of the Drawings
Fig. 1 is a perspective view of a slope mower embodying
the present invention.
Fig. 2 is a top plan view of the slope mower.
Fig. 3 is a cross-sectional view taken along line 3-3,
Fig. 2.
Fig. 4 is a rear elevational view of the slope mower
showing one adaptation of the mower to the terrain.
Fig. 5 is a rear elevational view of the slope mower
showing a second adaptation of the mower to the terrain.
Fig. 6 is an enlarged, fragmentary, cross-sectional
view of the slope mower taken along line 6-6, Fig. 2.
Fig. 7 is an enlarged, fragmentary view of the slope
mower taken along line 7-7, Fig. 2.
Fig. 8 is a reduced bottom plan view of the slope
mower.
Fig. 9 is an enlarged, fragmentary view of an internal
combustion engine and power takeoff assembly of the slope
mower.
Fig. 10 is an enlarged, fragmentary top plan view of a
front end of the slope mower showing a steering cylinder
arrangement.
Fig. 11 is an enlarged view of a leveling mechanism of
the slope mower.
Fig. 12 is a rear elevational view of the slope mower
showing another adaptation of the mower to the terrain.
Fig. 13 is a rear elevational view of the slope mower
showing another adaptation of the mower to the terrain.
Fig. 14 is an enlarged, fragmentary, stylized
perspective view of the slope mower illustrating the
hydraulic system.
Fig. 15 is an enlarged, fragementary, stylized
perspective view of the slope mower showing a remainder of
the hydraulic system.
Fig. 16 i5 a schematic diagram of the hydraulic
system.
Fig. 17 is a perspective view of a modified slope mower
embodying the present invention.
Fig. 18 is an enlarged rear elevational view of the
modified slope mower.
Fig. 19 is an enlarged and fragmentary bottom plan view
of the modified slope mower, showing one mower housing.
Fig. 20 is an enlarged and fragmentary top plan view of
the modified slope mower, showing one mower housing.
Fig. 21 is an enlarged and fragmentary side elevational
view of the modifed slope mower, showing one mower housing.
Fig. 22 is an enlarged and fragmentry cross-sectional
view of the modified slope mower, taken along line 22-22 of
Fig. 19.
Fig. 23 is a fragmentary bottom plan view of the
modified slope mower, ~howing mower housings thereof.
Fig. 24 is a fragmentary and enlarged front elevational
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view of the modifie~ slope mower, showing one mower housing
and side frame thereof adapting to terrain.
Fig. 25 is a rear elevational view of the modified
slope mower on a reduced scale, showing the mower housings
and vehicle frame thereof adapting to terrain.
Fig. 26 is an enlarged and fragmentary perspective view
of the modified slope mower, showing drive and pivot
mechanisms associated with a mower housing thereof.
Fig. 27 is an enlarged and fragmentary perspective view
of the modified slope mower showing height adjustment
associated with one of the mower housings.
De _iled Description of the Invention
As required, detailed embodiments of the present
invention are disclosed herein; however, it is to be
understood that the disclosed embodiments are merely
exemplary of the invention which may be embodied in various
forms. Therefore, specific structural and functional
details disclosecl herein are not to be interpreted as
limiting, but merely as a basis for the claims and as a
representative basis for teaching one skilled in the art to
variously employ the present invention in virtually any
appropriately detailed structure.
Referring in more detail to the drawings:
In Figs. 1 through 16, the reference numeral 1 refers
to a slop0 mower embodying the present invention. The mower
includes a lower vehicle frame 3, a front wheel 4, a rear
wheel 5, and operator seat 6. The mower 1 is powered by a
prime mover, such as an internal combustion engine 9, which
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is mounted on the frame 3 and connected to at least one, and
preferably both, of the front and rear wheels 4 and 5 for
movement across the ground.
A first blade housing 11 is pivotally connected to a
central section of the frame 3 and extends to the side of
the frame, as seen in Fig. 2. A second blade housing 12 is
also pivotally connected to the central section of frame and
extends from the other side of the frame 3. Rotatably
mounted in respective first and second blade housings 11 and
12 are first and second cutting blades 14 and 15.
Means for pivoting the first and second blade housings
11 and 12 are provided, such as respective first and second
hydraulic assemblies 17 and 18, explained in detail below.
The frame 3 is made from sheet metal or the like and
includes a cover 20 for shielding various components of the
mower 1. The mower 3 exhibits axes extending longitudinally
of the frame 3, and generally passing through the front and
rear wheels 4 and 5. A central axis A-A extends
longitudinally of the frame, but specifically generally
divides the frame into two equal sections. Thus, the mower
1 is generally divided into first and second, or left and
right, sections having generally corresponding parts on
either side of the mower 1. The terms "left" and "right"
are used in their normal context when looking toward the
front of the mower 1.
A leveling mechanism 19 is operatively connected to the
first and second hydraulic assemblies 17 and 18. The
leveling mechanism 19 senses changes in the attitude or
vertical orientation of the frame 3, and selectively
actuates one or both of the first and second hydraulic
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assemblies 17 and 18 to maintain the frame 3 in a generally
upright position. This enables the blade housings 11 and 12
to maintain ground contact, while the frame (and operator)
remain vertically oriented. As illustrated, the leveling
mechanism 19 is connected to the overall hydraulic system,
which is discussed in detail below.
As illustrated, a single front wheel 4 is connected to
a front section of the frame 3 by a steering mechanism 22
and is driven by a first hydraulic motor 23. The steering
mechanism 22 is connected to a hydraulic steering cylinder
assembly 24, as illustrated in Figs. 3 and 10.
The first and second blade housings 11 and 12 are
illustrated as being pivotally connected at a hinge 28,
which lies along the central axis A-A. Although the blade
housings are illustrated as being connected along the
central axis, it is envisioned that the first blade housing
11 could be pivotally connected to the frame 3 along a
longitudinal axis at or near the central axis, with a
similar situation being true for the second blade housing
12. This would likely result in two hinge connections
running generally parallel to one another near the central
axis A-A, but along respective horizontally spaced
longitudinal axes~
Each blade housing 11 and 12 has a respective top plate
29 and 30. Each top plate 29 and 30 is substantially
circular in shape, with the respective first and second
cutting blades 14 and 15 rotatably mounted to the respective
top plate 29 and 30 at centers thereof. As is seen in Fig.
8, each of the blade housings 11 and 12 (and top plates 29
and 30) are truncated in their circular shapes such that the
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hinge 28 generally defines a chord across the top plates 29
and 30.
Each of the top plates 29 and 30 has a depending side
wall 32 and 33 at a respective periphery thereof. The
depending side walls 32 and 33 do not extend along the hinge
28; thus, the blade housings 11 and 12 are open to each
other, forming a single blade housing cavity 35. The first
and second side walls 32 and 33 do not extend totally along
the circumferential periphery of the respective first and
second top plates 29 and 30, but are truncated at a point
near the central axis A-A and toward the rear of the blade
housings 11 and 12, as seen in Figs. 6, 7, and 8. The
truncation creates a discharge opening 37 near the rear
wheel 5 for permitting blade cuttings, such as weeds, grass,
and the like, to be expelled from the blade housing cavity
35 during operation of the vehicle.
A divider member 39 is attached to the hinge 28 at a
rear end thereof, as seen in Fig. 8. The divider member 39
is generally V-shaped with the point of the V-shape being
attached to the hinge 28. Thus, the divider member extends
rearwardly of the hinge 28 toward the rear wheel 5 and
serves to prevent significant amounts of blade cuttings to
be discharged under the rear wheel 5 as the mower 1 is
operated.
First and second outrigger wheels 41 and 42 are
adjustably connected to the first and second blade housings
11 and 12, respectively. The outrigger wheels 41 and 42
provide outer support for the blade housings 11 and 12 for
maintaining them in an elevated position above the ground.
The outrigger wheels 41 and 42 generally extend to the rear
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of the blade housings 11 and 12, but are preferably
positioned slightly forward of the forwardmost point of the
rear wheel 5. In practice, a two inch differential in
longitudinal spacing has been found to be an aid in steering
the slope mower 1 by reducing the tendency of the mower 1 to
wander from a given path during mowing. The outrigger
wheels 41 and 42 are pivotally connected to the first and
second blade housings 11 and 12, respectively, by first and
second linkage members 44 and 45, respectively. Each
linkage member 44 and 45 is pivotable about a respective
first and second pivot pin, 46 and 47, as seen in Fig. 2.
One end of each linkage member 44 and ~5 is connected to its
respective outrigger wheel 41 and 42. First and second
jackscrews 48 and 49 are connected to the other ends of the
first and second linkage members 44 and 45, respectively.
The first and second jackscrews 48 and 49 are used to adjust
the height at which the blade housings 11 and 12 are held
above the ground. Additional adjustment mechanisms are
included to accomplish this operation, as detailed below.
The first and second blade housings ll and 12 are also
equipped with first and second caster wheels 51 and 52,
respectively. Suitable first and second linkage arms 54 and
55 connect the first and second caster wheels 51 and 52,
respectively, to the associated blade housings ll and 12.
The linkage arms 54 and 55 are connected to the respective
first and second blade housings 11 and 12 at pivot pins 56,
as seen in Fig. 2. The caster wheels 51 and 52 are
connected to one end of the respective first and second
linkage arms 54 and 55. Respective first and second height
adjusters 58 and 59, mounted on respective first and second
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blade housings 11 and 12, are connected to another end of
the first and second linkage arms 54 and 55. The linXage
arms 54 and 55 can be pivoted about the pins 56 to vary the
height of the caster wheels 51 and 52. The height adjusters
58 and 59 are used to lock the caster wheels 51 and 52 in a
rough position relative to the blade housings 11 and 12.
The caster wheels are not used for transport of the mower 1,
but rather, are used to prevent scalping of the ground when
a slope or embankment is encountered. Thus, only rough
positioning of the caster wheels 51 and 52 is required.
Additional height adjustment means are included in
addition to the linkage member and jackscrew combinations
associated with thP first and second outrigger wheels 41 and
42. These means include an arrangement associated with the
hinge 28, including a locking nut assembly 61 releasably
connected to the hinge 28, as seen in Fig. 6. A pair of
locking nuts 61 are provided, at the front and rear ends of
the hinge 28, ancl each cooperates with a corresponding tab
62 depending from the frame 3, as seen in Figs. 6-8. Each
tab is provided with a slot 63, through which the locking
nut assembly 61 extends in a manner such that the blade
housings 11 and 12 and the hinge 28 can be raised and
lowered within the slots 63 and held in place by the locking
nut assemblies 61 in order to adjust the relative height of
the cutting blades 14 and 15 to the ground. When the
locking nut assemblies 61 are used in connection with the
jackscrews 48 and 49, both the center of the blade housings
11 and 12 and the outer sections thereof can be adjusted
together to maintain a level cutting path of the blades 14
and lS.
14
In order to power rotate the cutting blades 14 and 15,
first and second power take-off assemblies 68 and 69 are
provided. The power take-off assemblies 68 and 69 each
include a rotatable shaft 70 and 71 having one end connected
to a gear box 73, which is shared by the shafts 70 and 71,
as seen in Fig. 7. The gear box 73 is connected to the
internal combustion engine 9 by a belt drive system 74, as
well-known in the art and as illustrated in Fig. 9. Ou'er
ends of the rotatable shafts 70 and 71 are connected to
respective first and second rutting blade gear boxes 76 and
77. The rotational input of the shats 70 and 71 is
translated through the gear boxes 76 and 77 to respective
first and second cutting blade belt drive assemblies 78 and
79, which rotate first and second cutting blade spindles 80
and 81, which in turn receive the first and second cutting
blades 11 and 12 and rotate same.
As seen in Fig. 8, the first and second cutting blades
have overlapping paths, and they are placed approximately 90
degrees out of phase to avoid contact and to synchronize
their rotations. ~ecause they are connected to a mutual
gear box 73, the power take-off assemblies 68 and 69 rotate
the blades at the same speed, such that the blades 14 and 15
should never contact each other during operation. As is
also evident from Fig. 8, the blades 14 and 15 have reverse
rotations, such that each generally sweeps from front to
rear as it moves toward and then away from the hinge 28.
This configuration results in the cut grass being
efficiently expelled from the blade housings 11 and 12
through the discharge opening 37. Generally speaXing, the
first cutting blade 14 has a clockwise directional path when
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viewed from the top, and the second cutting blade 15 has a
generally counter clockwise directional path when viewed
from the top. When viewed from the bottom, as in Fig. 8,
the reverse charac-terizations ~re true. Although cutting
blades 14 and 15 are described herein, it ;s foreseen that
alternative cuttlng means, such as reel kype cutting
assemblies, can be provided.
The blade housings 11 and 12 are provided with
reinforcing members 83 and 84 for structural support.
The hydraulic system of the present invention includes
a fluid reservoir 90, a charge pump 91, a hydraulic fluid
cooler or radiator 92, and a transmission 93. In describing
the various components of the hydraulic system, a plurality
of ~luid lines will be referred to, all of which are
connected to their respective components by appropriate
fittings and the like.
The charge pump 91 and transmission 93 are mechanically
connected to and driven by the internal combustion engine 9
in a manner well-Xnown in the art. The transmission 93 is
operatively connected to the charge pump 91 for providing
forward, reverse, and neutral power modes for the front and
rear wheels 4 and 5. A gear selector 95 is provided for
this purpose, Fig. 9. The fluid cooler 92 is connected to
the transmission 93 by a fluid line 96 and serves to cool
the hydraulic fluid during operation. A fluid line 97
recycles the hydraulic fluid from the cooler 92 to the fluid
reservoir 90. The charge pump 91 draws hydraulic fluid from
the fLuid reservoir 90 through fluid line 990
The charge pump pressurizes the hydraulic fluid in the
system up to approximatsly 90 pounds per square inch gauge
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(psig) for use in powering the front and rear wheels 4 and
5. The charged fluid is transmitted from the charge pump 91
through the transmission 93 to fluid line 98. The hydraulic
fluid is pumped from the transmission 93 through a fluid
line 101, which tees for connection both to the first
hydraulic motor 23 and a second hydraulic motor 104. The
fIuid line 101 is connected to respective inlet ports to the
hydraulic motors 23 and 104. The charged fluid powers the
hydraulic motors 23 and 104 and is discharged therefrom
through discharge ports into a fluid return line 1~5. The
return line 105 is teed similarly to the fluid line 101 such
that fluid returning from each of the hydraulic motors 23
and 104 returns finally to the transmission 93 through a
single source. Appropriate control means are provided for
regulating the flow of fluid through line 101 and return
line 105 for powering the front and rear wheels 4 and 5.
The wheels are connected in parallel, such that an automatic
differential system is provided, whereby the hydraulic motor
23 or 104 that has the lowest torque thereon will pull or
push the mower 1 as the case may be. It is envisioned that
alternative means for driving the wheels 4 and 5 could be
provided to power both wheels.
Fluid for the leveling mechanism 19 and steering
mechanism 22 is discharged from the charge pump 91 through a
relief valve 108, which is connected to a fluid line 109. A
downstream end of the fluid line 109 is connected to a
steering valve 111, which is part of the steering mechanism
22. It is noted that the fluid in the line 109 is
"precharged" fluid, in that it is discharged from the charge
pump 91 prior to full charging (to 90 psig) of the fluid
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that is required for operation of the hydraulic motors 23
and 104. It can be seen in Fig. 14 that a return line 113
from the steering valve 111 discharges at a downstream end
into the fluid line 99 from the reservoir to the charge
pump. Thus, the leveling mechanism 19 and steering
mechanism 22 are operated by utilizing the same fluid as
does the hydraulic motors 23 and 104, but a lower pressure
in the lines is adequate.
The steering valve 111 is operated through rotation of
a steering wheel assembly 115 in a known manner. The
steering valve 111 is connected by a primary fluid line 116
and secondary fluid line 117 to the hydraulic cylinder
steering assembly 24. The hydraulic cylinder steering
assembly 24 includes a cylinder 119 having a first end 120
and a second end 121. Disposed within the cylinder 119 is a
piston~ as is well-known in the art, but not shown in the
figures. The piston is attached to a piston rod 122, which
extends through packing in the cylinder second end 121. The
piston separates fluid in communication with the primary
fluid line 116 at the cylinder first end from fluid end
communication with the secondary fluid line at the cylinder
second end. The piston and piston rod actuate according to
movement of the hydraulic fluid through the primary and
secondary fluid lines 116 and 117.
The piston rod 122 extends through a packing in the
cylinder second end, and an outer end of the piston rod 122
is attached to the steering mechanism 22, which includes a
crank arm 124 attached to a spindle assembly 125. Actuation
of the piston rod 122 in response to increased pressure in
either the primary or secondary fluid lines 116, 117,
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results in movement of the spindle assembly 125, and
ultimately in movement of the front wheel 4.
The steering valve 111 is responsive to rotation of the
steering wheel assembly 115 to use pressurized fluid from
the fluid line 109 to pressurize either the primary fluid
line 116 or secondary fluid line 117, depending on the
direction in which the wheel assembly 115 is turned. For
example, if the operator desires to turn left, as referenced
by a normal sitting position on the seat 6, the wheel is
turned counter clockwise. The steering valve 111 opens the
primary fluid line 116 to pressure, whereby fluid is forced
into the cylinder first end 120, moving the piston and
piston rod 122 outwardly and forcing fluid out of the
cylinder second end 121 into the secondary line 117. As the
piston rod is extended away from the cylinder 119, the crank
arm 124 and spindle assembly 125 are rotated generally
counter clockwise, w~ich actuates the steering mechanism 22
to turn the wheel to the left. To make a right turn, the
reverse is true, such that pressurized fluid is forced
through the secondary fluid line 117 into the cylinder
second end 121, forcing the piston and piston rod 122 toward
the cylinder first end. This forces fluid out of the
cylinder first end 120 and turns the crank arm 124, spindle
assembly 125, and overall steering mechanism 22 to the
right.
The leveling mechanism 19 comprises a main leveling
valve 128, relay switches 129 and 130, level sensor 131, and
accumulator cylinder 132. As illustrated in Fig. 16, these
components are located in a front section 137 of the frame
3. A fluid line 139 connects the steering valve 111 to the
19
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main leveling valve 1~8, entering through an inlet port 140.
The main leveling valve 128 is an electric valve of the type
well-known in the art for responding to electrical impulses
to open and close various ports. The valve 128 has an
outlet port 142, to which is connected a fluid line 144.
The fluid line 144 connects the outlet port 142 to an oil
filter assembly 145. In turn, the oil filter assembly 145
is connected to the transmission 93 by a fluid return line
147.
It can be seen from the schematic diagram in Fig. 16
and the stylized perspectives in Figs. 14 and 15, that fluid
can flow in a circuit from the charge pump 91 through the
steering valve assembly 111, the main leveling valve 128,
the filter 145, and the transmission 93, back to the charge
pump 91. To accomplish this, the steering valve 111 simply
allows the hydraulic fluid to flow through it, when the
steering mechanism 22 is not in use, and to the main
leveling valve 128. When the steering mechanism 22 is used,
the steering valve 11 diverts at least a portion of the
fluid through the primary and secondary fluid lines 116 and
117 for operation of the steering mechanism.
When the mower 1 is in an equilibrium position such
that no adjustment of the first and second hydraulic
assemblies 17 and 18 is necessary, the leveling valve 128
operates to direct the fluid from the inlet port 140 and out
the outlet port 142 onto the filter assembly 145 for return
to the transmission 93 and charge pump 91. In this
situation, the fluid is merely recirculated through the
system until such time as a leveling operation is required.
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The main leveling valve 128 has a first auxiliary port
151 and a second auxiliary port 152. The first auxiliary
port 151 is connected to a four-way cross member 154 for
permitting flow from the first auxiliary port 151 to three
other components discussed below. The second auxiliary port
152 is equipped with a tee member for allowing flow to two
other components.
The four-way cross member 154 permits flow
communication from the first auxiliary port 151 to the ~-
first, or left, hydraulic assembly 17. Flow communication
is provided to the accumulator cylinder 132 from the cross
member 154 through a fluid line 158. Lastly, flow
communication is provided from the cross member 154 to a
manual side lift valve assembly 160 through a fluid line
159.
Flow communication is provided between the tee member
155 and the second, or right, hydraulic assembly 18 through
a fluid line 163. A fluid line 164 connects the tee member
155 to the manual side lift valve assembly 160.
The first and second hydraulic assemblies 17 and 18
(also referred to as left and right hydraulic assemblies,
respectively) each comprise a first, or left, leveling
cylinder 167 and a second, or right, leveling cylinder 168,
each having appropriate connecting lugs and piston and
piston rod assemblies as are well-known in the art. As best
seen in Figs. 2 and 6, the leveling cylinder lugs are
pivotally connected to the mower frame 3, and piston rod
free ends are pivotally connected to the blade housings 11
and 12, respectively. The leveling cylinders 167 and 168
are connected to their respective blade housings 11 and 12
i2~
in a manner known in the art such that actuation of the
piston rods pivots the respective blade housings about the
central hinge 28.
The fluid line 157 is connected to an outer end of the
first leveling cylinder 167 for regulating hydraulic fluid
flow to the cylinder on one side of the cylinder piston. A
fluid line 171 connects an inner end of the first, or left,
leveling cylinder to a manual side lift valve 160. When the
manual side lift valve 160 is in a neutral position, fluid
can flow from the tee member 155, thxough line 164, the side
lift valve 160, and into the fluid line 171 for
communication with the first leveling cylinder 167 on the
other side of the cylinder piston.
The fluid line 163 connects an outer end of the second,
or right, leveling cylinder 168 to the tee member 155.
Thus, fluid can flow from the tee member 155 into the outer
end of the second leveling cylinder 168 on one side of the
cylinder piston. Fluid flow from an inner end of the second
leveling cylinder 168, and thus from the other side of the
cylinder piston, is established through a line 172 to the
side lift valve assembly 160. When the side lift valve
assembly 160 is in a neutral position, flow communication is
established between the inner end of the leveling cylinder
168 and the cross member 154 through fluid line 172, the
manual side lift valve 160, and finally the fluid line 159.
As is evident from the drawings, the tee member 155,
when the side lift valve 160 is in its neutral position,
allows for fluid flow between the second auxiliary port 152
and, simultaneously, the outer end of the second leveling
cylinder 168 and the inner end of the first leveling
~o
cylinder 167. Thus, fluid flow from the second auxiliary
port 152 through the tee member 155 simultaneously acts on
an inner side of the cylinder piston in the first leveling
cylinder 167 and an outer side of the cylinder piston in the
second leveling cylinder 168.
It can also be seen from the drawings, particularly
Fig. 16, that simultaneous flow is possible from the first
auxiliary port to the outer end of the first leveling
cylinder 167, the inner end of the second leveling cylinder
168, and the accumulator 132. The level sensor 131 is
provided to actuate the electric main leveling valve 128.
The leveling valve 128 responds to electric input from the
level sensor 131 to open and close the first and second
auxiliary ports 151 and 152 as necessary to level the frame
3, which is to say to keep the frame 3 in a generally
vertical orientation.
The level sensor 128 is detailed in Fig. 11, and is
electrically connected to the ~witches 129 and 130, which in
turn are electrically connected to opposite ends of the main
leveling valve 128. The level sensor comprises a curved
tube 175 connected to a support structure 176, which in turn
is attached to the frame 3. The tube 175 is illustrated as
being filled with a fluid, such as kerosene, and has a steel
ball 179 therein. The present tube 175 and ball 179
arrangement also works well if the fluid in the tube 175 is
a gas such as air, which makes the sensor respond more
quickly. The bottom part of the curve in the tube 175 is at
a lower position than either a first end 181 or a second end
182 of the tube 175. Situated in both the first and second
ends 181 and 182 are suitable sensors, which are activated
,, ~ , : - ' '~-" . ' ' . ' ' .
.:
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upon contact of the ball 179. When the frame 3 shifts
either to the right or the left, as when the machine is
operated on a slope, the ball 179 will roll to either the
first or second end 181, 182 of the tube 175, as the case
may be. Upon contacting the associated sensor, an
electronic impulse is relayed to the main leveling valve
128, for actuation of the valve 128 to open or close the
ap~ropriate auxiliary port.
Figs. 4, 5, 12, and 13 illustrate various slopes that
may be encountered during operation of the mower 1. The
described valving system is responsive to all such
situations to extend or retract the piston rods associated
with the first and second leveling cylinders 167 and 168 to
maintain the frame 3 in its upright position. The curved
tube 175 filled with kerosene has been found to work well
with the present invention, but applicants are not limited -
to a specific means of sensing the orientation of the frame
3. However, it has been found that the illustrated
assemblage of components works well in practical use, since
the kerosene and ball arrangement is not overly responsive
to changes in attitude of the frame 3. For example, it has
been found that mercury switches tend to be too responsive,
such that the frame 3 undergoes constant shifting, which can
be distracting to the operator. The illustrated embodiment
permits the frame 3 to shift slightly before it responds, so
that changes are more gradual and less distracting to the
operator.
The specific hydraulic valving systems disclosed
operate in a manner well-known in the art; thus, it is not
necessary to describe each different valving alternative.
24
~2~77500
Fig. 13 illustrates the most common situation, that is,
where the mower 1 is being operated on a slope. It has been
found that the present invention can be operated on slopes
of up to about 30 degrees from the horizontal.
In the situation shown in Fig. 13, as the mower 1 moves
into the slope, it will tend to tilt to the left, ana the
steel bal~ 179 contacts the sensor associated with the tube
first end 181. The electric main leveling valve 128 is
actuated to open the second auxiliary port 152, whereby
pressurized fluid is forced into line 163, and line 171 (via
line 164), which tends to retract the piston rod associated
with the right leveling cylinder 16~, and extend the piston
rod associated with the left leveling cylinder 167. Fluid
is simultaneously forced through line 171 into line 159 and
cross member 154. At the same time, fluid from the left
leveling cylinder 167 is being forced through line 157 to
the cross member 154. This fluid exits through line 144.
The accumulator 132 in this instance provides an amount
of spring, to cushion the transference of the fluid. The
accumulator 132 is charged with an inert gas, such as
nitrogen, and has a piston therein. In the piston's
expanded position, the accumulator has an amount of pressure
approximately equal to the pressure in the overall hydraulic
leveling system, which is abo~t 90 psig. However, the
accumulator can be compressed such that the pressure therein
is on the order of 600 psig. Excess oil generally is forced
into the accumulator when both blade housings 11 ~nd 12 are
pulled up, as in Fig. 12.
It can be seen that by appropriate movement of the
leveling valve 128, in respon~e to the level sensor 130, the
1277500
first and second hydraulic assemblies 117 and 118 are
retracted or extended as necessary to maintain the blade
housings 11 and 12 in contact with the ground, and the frame
3 in a generally upright position.
The manual side lift valve 160 is provided to override
the leveling system so as to force a selected one of the
blade housings 11 and 12 into an elevated position, such as
for changing an associated cutting blade 14 and 15. Th~
manual side li~t valve 160 is connected to the filter 145
through a fluid line 185 for recycling of excess oil during
a side lifting operation. By appropriate manipulation of
the side lift valve 160, the leveling system is overridden,
and fluid is forced into one side of a selected leveling
cylinder 167, 168, through either line 171, or 172. The
side lift valve 160 overrides the natural tendency of the
other leveling cylinder to react in unison with the selected
leveling cylinder, and said excess oil is displaced through
the line 185 to the filter 145 for recirculation.
Fig. 17 through 27 illustrate a first modified
embodiment of a slope mower according to the present
invention, generally designated by the numeral 300. The
slope mower 300 is similar in many respects to the mower 1
and equivalent features will not be discussed in great
detail herein.
l~e slope mower 300 includes a main vehicle frame or
body 303, a front wheel 304, a rear wheel 305, a first mower
30s3, a second mower 309, a first side support frame 310 and
a second side support frame 311.
The vehicle body 303 is quite similar to the frame 3 of
the previous embodimen and, therefore, will not be
26
~277500
discussed in detail. The vehicle body 303 incorporates
therein a prime mover or engine of the type described for
the previous e~bodiment.
The first mower 308 includes a housing 316 having a
first blade 317 and a second blade 318 rotatably mounted
therein. The first and second blades 317 and 318 are driven
by pulleys 31~ and 320 respectively which are in turn driven
by drive belts 321 and 322. In particular the drive belt
321 drives the pulley 320 and the drive belt 322 is driven
by the pulley 320 to drive the pulley 319.
The drive belt 321 is in turn driven by a pulley 325
which is driven by a gear reduction device 326 mounted upon
the housing 316. The gear reduction device is in turn
connected by a drive shaft 329 and by a pair of universal
joints 330 and 331 to the prime mover.
The housing 316 is pivotally mounted, on the side
thereof closest to the mower body 303, so as to generally
rotate about an axis which is parallel to an axis passing
through the wheels 304 and 305 and closely spaced relative
thereto. In particular the housing 316 is connected by a
strut 338 to an a~le 339 in turn connected to a height
adjustment plate 340. The plate 340 is L-shaped and extends
upwardly from the connection thereof with the strut 338. An
adjustment structure 343 (see Fig. 27) is fixedly attached
to and depends from the bottom of the vehicle body 303
intermediately therealong.
The adjustment structure 343 includes a pair of spaced
and vertically aligned plates 344 and 345 each having a
plurality of equally spaced and horizontally aligned
apertures 346 passing therethrough. A bar 348 of
27
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00
approximately the same diameter as the apertures 346 extends
through a pair of the horizontally aligned apertures 346 and
can be selectively adjusted and secured in position by an
ope.rator along the vertically positioned apertures 346
An upper section 350 of the adjustment plate 340
extends over the bar 348. In this manner the height of the
inner side of the mower housing 316 can be adjusted relative
to the height of the mower vehicle body 303. Extending
forwardly of the mower housing 316 is a strut 352 having
mounted therein a vertical axle 353 supporting a clevis 354
and a freely turning wheel 355. The height of the strut 352
and, consequently, the mower housing 316 at that location is
adjustable relative to the wheel 355 by placement of washers
and the like between the strut 352 and clevis 354, so as to
adjust the outer mowing height of the first mower 8. An
antiscalping wheel or roller 359 is pivotally attached to
the mower housing 316 near the outer end thereof opposite
the wheel 355. A chain 360 loosely supports the housing 316
beneath the first side support frame 310.
The second mower 9 includes a housing 362 covering a
pair of internally and pivotally mounted cutting blades 363
and 364. The housing 362 is generally a mirror image of the
housing 316, except that the blades 363 and 364 are aligned
to rotate at angles of ninety degrees to the blades 317 and
318, as seen in Fig. 23.
The first side support frame 310 comprises two radial
members 370 and 371 joined near outer ends thereof with a
axially aligned member 372. The axial aligned member has a
downwardly extending trailing section 375 upon which is
rotatably mounted a wheel 376. The wheel 376 has an axis of
.
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rotation which is generally parallel to the axis of rotation
of the rear wheel 305. The inner ends of the radial members
370 and 371 are pivotally attached to the vehicle body 303
by pivot structures 378 and 379 respectively. The support
frame 310 is also connected to the mower vehicle body 303 by
a hydraulic ram 384 having a first pivotal connection 385
connecting the ram to the frame member 372 at one end
thereof and a second pivotal connection 386 at an opposite
end thereof connecting the ram 384 to the vehicle body 303.
10 The ram 304 is operably connected to the hydraulic system of
the mower 301 to maintain a downward pressure on the frame
310 as the mower 301 traverses various terrain. The
structure for maintaining the pressure on the frame 310 by
the hydraulic ram 384 is quite similar to the structure
described for the previous embodiment for this purpose and
will not be redescribed herein.
The second side support rame 311 is quite similar to
but a mirror imag~o of the first side support frame 310. In
particular the second side support frame 311 includes an
20 outrigger wheel 390 pivotally mounted near the radially
outward side of the frame 311 at a spaced location from the
vehicle body 303 and spaced from the vehicle wheels 304 and
305. The frame 311 is also pivotally connected to the body
frame along an axis of rotation which is parallel aligned to
an axis passing through the wheels 304 and 305. A hydraulic
ram 391 pivotally connected to the vehicle body 303 and to
the outer side of the frame 311 operably biases the frame
311 downwardly under control of an attitude adjustment
system associated with the slope mower 1 which controls the
30 hydraulic pressure to the ram 391 in a manner similar to the
29
control of the ram 384.
In operation the slope mower 301 of the second
embodiment is similar to the slope mower 1 of the first
embodiment in that the attitude of the relatively thin
vehicle body 303 mounted on spaced front and rear wheels 304
and 305 is maintained in a general vertical orientation by
operation of the hydraulic system on the side frames 310 and
311. In particular, as the vehicle passes over various
terrain the wheels 390 and 376 are operably biased against
the ground by the rams 391 and 384 respectively so as to : :
maintain the vehicle body 303 in an upright orientation.
Operation of the 301 mower over different types of terrain
can be seen in Figs. 18 and 25.
The major difference between the slope mower 301 and
the mower 1 is that the first and second mowers 308 and 309
of the present embodiment are generally independently
mounted relative to the support frames 310 and 311. This
allows the mowers 308 and 309 to be constructed of lighter
material and to more easily follow the contour of the
ground. This can be seen in Fig. 24. In particular, the
second mower 309 is able to rotate upwardly so as to ride
over a slight rise in the contour of the land beneath the
mower 309, while the support frame wheel 376 follows a
different contour. However, the mower 308 is connected by
the chain 360 to the first frame 310 so that the operator
can raise the mower 308 by override of the hydraulic system
working through the ram 384, to raise the first support
frame 310 into a raised and non-ground following
orientation.
It is to be understood that while certain orms of the
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127 7~00
present invention have been illustrated and described
herein, it is not to be limited to the specific forms or
arrangement of parts described and shown.
:, : . .
