U.S. patent application number 09/333175 was filed with the patent office on 2002-02-14 for steerable cutting unit with steerable and level lift grass catcher.
Invention is credited to BOHM, HOWARD H., LAMUSGA, GARY R., SALLSTROM, STEVEN A..
Application Number | 20020017086 09/333175 |
Document ID | / |
Family ID | 23301641 |
Filed Date | 2002-02-14 |
United States Patent
Application |
20020017086 |
Kind Code |
A1 |
SALLSTROM, STEVEN A. ; et
al. |
February 14, 2002 |
STEERABLE CUTTING UNIT WITH STEERABLE AND LEVEL LIFT GRASS
CATCHER
Abstract
A mower includes a traction frame that supports at least one
cutting unit and a grass catcher associated with each cutting unit.
The cutting unit and grass catcher are both operatively coupled to
the traction frame such that they both jointly are able to steer or
yaw together during turns of the traction frame. This permits the
gap between the cutting unit and a grass basket which is part of
the grass catcher to remain constant whether the traction frame is
travelling straight or is turning. This ensures that the grass
clippings will be properly retained in the grass basket without
dribbling out of the grass basket. In addition, a system is
provided for keeping the grass catcher level as it is lifted up out
of engagement with the ground into a raised, transport position,
also to better retain the grass clippings within the grass
basket.
Inventors: |
SALLSTROM, STEVEN A.;
(PLYMOUTH, MN) ; LAMUSGA, GARY R.; (PRIOR LAKE,
MN) ; BOHM, HOWARD H.; (CRYSTAL, MN) |
Correspondence
Address: |
JAMES W MILLER
SUITE 1005 FOSHAY TOWER
821 MARQUETTE AVENUE
MINNEAPOLIS
MN
55402
|
Family ID: |
23301641 |
Appl. No.: |
09/333175 |
Filed: |
June 14, 1999 |
Current U.S.
Class: |
56/7 |
Current CPC
Class: |
A01D 34/62 20130101;
A01D 2101/00 20130101; A01D 43/063 20130101; A01D 34/42
20130101 |
Class at
Publication: |
56/7 |
International
Class: |
A01D 075/30 |
Claims
We claim:
1. A mower, which comprises: (a) a traction frame; (b) a reel-type
cutting unit having a cutting unit frame, a rotatable reel and
cooperating bedknife carried on the cutting unit frame, and front
and rear rollers carried on the cutting unit frame for allowing the
cutting unit to rest on and roll over the ground when the cutting
unit is disposed in a cutting position in engagement with the
ground as the traction frame moves over the ground, the cutting
unit having a weight distribution or loading of an instantaneous
nominal value when the cutting unit is resting on level, flat
ground; (c) wherein the cutting unit is operatively coupled to the
traction frame in a manner that permits the cutting unit to roll
about a horizontal longitudinal x axis and to pitch about a
horizontal transverse y axis to follow the ground contour and to
steer or yaw about a vertical z axis when the traction frame is
turning, and wherein the cutting unit is operatively coupled to the
traction frame such that the cutting unit steers or yaws about a
steering point that is located above and in front of the cutting
unit such that the cutting unit casters about this steering point
during turns of the traction frame; and (d) wherein the cutting
unit is operatively coupled to the traction frame in a manner such
that the weight distribution or loading on the cutting unit remains
substantially at the instantaneous nominal value thereof even as
the cutting unit steers or yaws during turns of the vehicle.
2. A mower, which comprises: (a) a traction frame; (b) a reel-type
cutting unit operatively coupled to the traction frame in a manner
that permits the cutting unit to steer or yaw during turns of the
traction frame; and (c) a grass catcher operatively coupled to the
traction frame, the grass catcher being located adjacent the
cutting unit for receiving grass clippings from the cutting unit,
the grass catcher being supported independently of the cutting unit
such that the weight of the grass catcher and accumulated grass
clippings therein is not substantially carried by the cutting unit,
and the grass catcher also being operatively coupled to the
traction frame in a manner that permits the grass catcher to also
steer or yaw during turns of the traction frame.
3. The mower of claim 2, wherein the reel-type cutting unit and the
grass catcher steer together in the same direction and in
approximately the same amount during turns of the traction
frame.
4. The mower of claim 2, wherein the grass catcher further includes
a substantially vertical pivot axis connection to the traction
frame to permit the grass catcher to steer or yaw relative to the
traction frame.
5. The mower of claim 4, wherein the grass catcher comprises a
support frame and a grass basket releasably connected to the
support frame for receiving and retaining the grass clippings, and
wherein the vertical pivot axis connection is located on the
support frame.
6. The mower of claim 4, wherein the vertical pivot axis connection
on the grass catcher is carried on a lift frame for raising and
lowering the grass catcher relative to the ground, the lift frame
being pivotally connected to the traction frame for rotation about
a substantially horizontal pivot axis on the traction frame such
that the grass catcher is raised and lowered relative to the ground
as the lift frame pivots upwardly and downwardly relative to the
traction frame about the substantially horizontal pivot axis on the
traction frame.
7. The mower of claim 6, wherein the grass catcher comprises: (a) a
forked support frame having spaced apart, downwardly extending legs
connected by a cross member; and (b) a grass basket releasably
connected to the support frame and extending between the legs of
the support frame for receiving and retaining the grass
clippings.
8. The mower of claim 7, wherein the vertical pivot axis connection
is located on the cross member of the support frame.
9. The mower of claim 6, wherein the grass catcher is further
pivotally carried on the lift frame for rotation about a
substantially horizontal pivot axis on the lift frame to adjust the
orientation of the grass catcher relative to the lift frame as the
lift frame pivots upwardly and downwardly.
10. The mower of claim 9, further including a tilt rod extending
between the traction frame and the grass catcher to positively tilt
the grass catcher forwardly as the lift frame rises.
11. The mower of claim 10, wherein the tilt rod is configured such
that the amount of the forward tilting of the grass catcher is
sufficient to at least keep the grass catcher level as it
lifts.
12. The mower of claim 9, further including a grass catcher
transport bracket carried on the lift frame for engaging the grass
catcher as the grass catcher lifts and for straightening the grass
catcher about the vertical pivot axis connection to place the grass
catcher in a substantially perpendicular orientation relative to
the traction frame's direction of movement.
13. The mower of claim 2, wherein the traction frame is part of a
self-propelled riding vehicle.
14. The mower of claim 2, further including a plurality of cutting
units and a plurality of grass catchers operatively coupled to the
traction frame, wherein each cutting unit has one grass catcher
associated therewith for receiving the grass clippings from such
cutting unit.
15. A mower, which comprises: (a) a traction frame; (b) a reel-type
cutting unit operatively coupled to the traction frame; (c) a grass
catcher operatively coupled to the traction frame, the grass
catcher being located adjacent the cutting unit but with the weight
of the grass catcher being supported independently of the cutting
unit, the grass catcher including a grass basket for receiving
grass clippings from the cutting unit with the grass basket having
a mouth through which the grass clippings are thrown with the mouth
of the grass basket being spaced from the cutting unit by a gap;
and (d) wherein the reel-type cutting unit and the grass catcher
are both operatively coupled to the traction frame in a manner that
allows both the reel-type cutting unit and the grass catcher to
steer or yaw during turns of the traction frame with the gap
between the mouth of the grass basket and the cutting unit
remaining substantially constant whether the traction frame is
travelling straight or is turning.
16. The mower of claim 15, further including a lift and lower
system for raising and lowering both the cutting unit and the grass
catcher relative to the ground between a raised transport position
and a lowered cutting position, respectively, and wherein the lift
and lower system is configured to at least maintain the grass
catcher level relative to the ground in its raised transport
position.
17. The mower of claim 15, further including a plurality of cutting
units and a plurality of grass catchers operatively coupled to the
traction frame, wherein each cutting unit has one grass catcher
associated therewith for receiving the grass clippings from such
cutting unit.
18. A mower, which comprises: (a) a traction frame; (b) a grass
catcher operatively coupled to the traction frame to be propelled
by the traction frame, wherein the grass catcher comprises: (i) a
forked support frame having spaced apart, downwardly extending legs
connected by a cross member; and (ii) a grass basket releasably
connected to the support frame and extending between the legs of
the support frame for receiving and retaining the grass clippings,
the grass basket having a rearwardly facing mouth when connected to
the support frame; (c) a substantially vertical pivot axis
connection between the cross member of the forked support frame and
the traction frame such that the grass catcher can pivot about the
vertical pivot axis connection; (d) a reel-type cutting unit
trailing the grass catcher and arranged adjacent thereto such that
the reel-type cutting unit throws grass clippings into the grass
basket through the mouth of the grass basket; and (e) two pull link
arms extending between the legs of the support frame and opposite
sides of the reel-type cutting unit for pulling the cutting unit
forwardly as the traction frame propels the support frame
forwardly, the two pull link arms being configured relative to the
cutting unit and the support frame to permit the cutting unit to
roll and pitch about longitudinal and transverse horizontal axes to
follow the ground contour, and the two pull link arms allowing the
cutting unit and the grass catcher to steer or yaw together about
the substantially vertical pivot axis connection during turns of
the traction frame.
19. The mower of claim 18, wherein the cutting unit is supported by
front and rear rollers for rolling over the ground, and wherein the
two pull link arms connect to the cutting unit at generally the
same height as a rotational axis of the front roller such that the
cutting unit can steer or yaw without inducing a roll in the
cutting unit.
20. The mower of claim 18, wherein the support frame of the grass
catcher is operatively coupled to the traction frame by a lift
frame that is pivotally connected at one end to the traction frame
and at the other end is connected by the substantially vertical
pivot axis connection to the cross member of the support frame of
the grass catcher.
21. The mower of claim 20, further including a lift arm pivotally
connected at one end to the traction frame for lifting the cutting
unit.
22. A mower, which comprises: (a) a traction frame; (b) a reel-type
cutting unit operatively coupled to the traction frame; (c) a grass
catcher operatively coupled to the traction frame, the grass
catcher being located adjacent the cutting unit for receiving grass
clippings from the cutting unit, the grass catcher being supported
independently of the cutting unit such that the weight of the grass
catcher and accumulated grass clippings therein is not
substantially carried by the cutting unit; (d) a lift frame
attached to the grass catcher for raising and lowering the grass
catcher relative to the ground, the lift frame being pivotally
connected to the traction frame for rotation about a substantially
horizontal pivot axis on the traction frame such that the grass
catcher is raised and lowered relative to the ground as the lift
frame pivots upwardly and downwardly relative to the traction frame
about the substantially horizontal pivot axis on the traction
frame, and the lift frame further being pivotally connected to the
grass catcher such that the grass catcher pivots about a
substantially horizontal pivot axis on the lift frame to adjust the
orientation of the grass catcher relative to the lift frame as the
lift frame pivots upwardly and downwardly relative to the traction
frame; and (e) a tilt rod extending between the traction frame and
the grass catcher to positively tilt the grass catcher forwardly as
the lift frame rises.
23. The mower of claim 22, wherein the tilt rod is configured such
that the amount of the forward tilting of the grass catcher is
sufficient to at least keep the grass catcher level as it
lifts.
24. The mower of claim 22, wherein the grass catcher also includes
a substantially vertical pivot axis connection to the lift frame to
permit the grass catcher to steer or yaw during turns of the
traction frame when the grass catcher is in a lowered cutting
position.
25. The mower of claim 22, wherein the traction frame is part of a
self-propelled riding vehicle.
Description
TECHNICAL FIELD
[0001] This invention relates to a mower having a steerable
reel-type cutting unit. This invention also relates to a mower
having a steerable grass catcher associated with a steerable
reel-type cutting unit in which the grass catcher is supported on a
frame separate from the cutting unit so that the weight of the
grass catcher is not carried on the cutting unit. More
particularly, this invention relates to such a mower in which the
grass catcher as well as the cutting unit can be raised and lowered
between a cutting position and a transport position.
BACKGROUND OF THE INVENTION
[0002] Mowers equipped with reel-type cutting units are well known
for precision mowing on golf courses and the like. For example, a
riding greensmower comprises a traction vehicle on which multiple
reel-type cutting units are mounted for mowing golf greens or
similar surfaces. Each cutting unit typically comprises a rotatable
reel that sweeps the grass against a fixed bedknife and front and
rear rollers for allowing the cutting unit to roll over the ground.
A grass catcher is mounted generally in front of the cutting unit.
The grass catcher includes a grass basket having a rearwardly
facing mouth into which the cutting unit throws grass clippings
during operation of the greensmower.
[0003] In some known mowers of this type, the cutting units can
steer themselves about high steering points, i.e. steering points
located above the cutting unit, during turns of the mower. For
example, if the mower turns to the right, the cutting units
similarly steer or yaw to the right in response to the turn.
However, in so steering or yawing, these known mowers tend to roll
the cutting unit about a longitudinal, horizontal axis such that
the end of the cutting unit on the inside of the turn becomes more
heavily loaded than the end of the cutting unit on the outside of
the turn. This can gouge or scuff the turf which is obviously
undesirable. This uneven loading or uneven weight distribution on
the cutting unit can also occur when the cutting unit rolls to
follow the ground contour even when the cutting unit is travelling
straight.
[0004] In addition, most of the known reel mowers having steerable
cutting units also support the grass basket on the cutting unit
itself. Thus, as the grass basket fills with clippings, the weight
of the grass basket and the clippings is substantially carried or
borne by the cutting unit. A grass basket can hold thirty pounds or
so of grass clippings. This additional weight is effectively
transferred to the cutting unit frame and lowers the height of cut
of the reel from the nominal height the reel cuts when the grass
basket is not attached or is empty. This change in the height of
cut is also undesirable.
[0005] At least some mowers manufactured by The Toro Company, the
assignee of this invention, do not place the weight of the grass
catcher on the cutting unit to thereby avoid the undesirable change
in the height of cut described above. In these mowers, the grass
catcher is carried on a support frame that attaches to the mower
rather than to the cutting unit such that the weight of the grass
catcher and its clippings is not substantially carried by the
cutting unit. Further, the cutting unit is often towed or propelled
by the grass catcher support frame through two pull link arms that
extend from the grass catcher support frame to each side of the
cutting unit. While the ends of the pull link arms at-2 to the
cutting unit through ball joints to let the cutting unit roll and
pitch relative to the ground to follow the ground contour, the pull
link arms and their attachment to a non-steerable grass catcher
support frame do not allow the cutting unit to steer or yaw during
turns of the mower. Thus, these cutting units slightly skid or
wobble during turns.
[0006] U.S. Pat. No. 5,533,326, which is assigned to The Toro
Company, the assignee of this invention, replaces the two pull link
arms on known prior Toro mowers with a single pull link arm
attached by a ball joint to the front and middle of the cutting
unit. This cutting unit now has movement in all three axes and
specifically can steer or yaw during turns of the mower. However,
the grass catcher in this mower does not similarly turn or yaw in
the same way as the associated cutting unit. Thus, the spacing
between the mouth of the grass basket and the cutting reel varies
across the width of the cutting unit during a turn. The spacing
changes during a turn with the side of the cutting reel on the
inside of the turn moving further away from the grass basket and
the side of the cutting reel on the outside of the turn moving
closer to the grass basket.
[0007] This spacing change between the cutting unit and the grass
basket can lead to certain operational difficulties. These
difficulties include the cutting reel engaging and damaging the
grass basket as well as the grass clippings not being properly
thrown into the grass basket or falling out of the grass basket in
the gap between the cutting unit and the grass basket. To avoid
these difficulties, the mower shown in the 326 patent has a partial
front shield between the cutting reel and the grass catcher and a
flexible seal or barrier extending between this front shield and
the mouth of the grass basket.
[0008] The use of a front shield/flexible seal as shown in the 326
patent is effective for compensating for the potential problems
caused by the change in spacing between the grass basket and the
cutting unit during turns. However, when cutting wet and/or sticky
grass, the front shield and flexible seal present surfaces and
edges to which the grass can adhere and build-up. This build-up can
be so extreme that the cutting unit becomes plugged with the area
between the grass catcher and the cutting unit, i.e. the area on
the top of the flexible seal, becoming more or less substantially
filled with grass clippings. Also, the clumps of accumulated
clippings occassionally fall to the ground, leaving an unsightly
mess. This requires that the mower be stopped and cleaned, which is
obviously something that is best avoided. Accordingly, there is a
need in the art for another way of solving any problems that are
caused by the fact that in some mowers the cutting units can steer
during turns of the mower while their separately supported grass
catchers cannot.
[0009] Mowers of this type also have a lift and lower system for
lifting and lowering the cutting units and their grass catchers
between cutting and transport positions. In fact, this is done
frequently when mowing a green since the operator will lift the
cutting units and grass catchers at the end of one pass while the
mower is swung around off the green to prepare for another pass and
will then lower the cutting units and grass catchers back down as
the mower approaches the green for the next cutting pass. One
difficulty with some known grass catcher designs is that the
baskets tip rearwardly as they are lifted with the result that some
clippings could fall out of the baskets when they are lifted. If
the flexible seal of the 326 patent is removed, the clippings that
fall out of the grass basket would then dribble down onto the
ground or fall into the cutting unit, both of which are
undesirable.
[0010] U.S. Pat. No. 3,408,801 to Kroll, which is assigned to the
Toro Manufacturing Corporation, the predecessor of the assignee of
this invention, The Toro Company, discloses a walk behind
greensmower having a single cutting unit and grass catcher. The
grass catcher in the 801 patent has brackets on the sides of the
grass catcher which receive pins on the frame of the mower. This
pin/bracket configuration allows the grass catcher to shift on the
frame of the mower when the user lifts the front of the mower by
pushing down on the handle of the mower. The shift in the grass
catcher is designed to maintain the grass catcher in a level
orientation or even to allow the grass catcher to tip forwardly
relative to the mower, thereby to better retain the clippings in
the grass catcher.
[0011] The pin/bracket configuration shown in the 801 patent does
not directly and positively keep the grass catcher level or tipped
forwardly during lifting of the front of the mower. It relies on
the force of gravity acting on the various components and would be
affected by the weight distribution of the clippings inside the
grass catcher. Thus, there may be some conditions in which the
grass catcher would not reliably shift or tip forwardly during
lifting of the front of the mower. Also, the pin/bracket
connections shown in the 801 patent potentially would provide
excessive movement of the grass basket relative to the mower
expecially when used on a riding mower capable of relatively higher
speed operation. Accordingly, there is still a need in the art for
a leveling system for a grass catcher which acts positively on the
catcher to ensure that the catcher will always be maintained in a
desired position as the lift and lower system operates.
SUMMARY OF THE INVENTION
[0012] One aspect of this invention relates to a mower which
comprises a traction frame. A reel-type cutting unit is provided
having a cutting unit frame, a rotatable reel and cooperating
bedknife carried on the cutting unit frame, and front and rear
rollers carried on the cutting unit frame for allowing the cutting
unit to rest on and roll over the ground when the cutting unit is
disposed in a cutting position in engagement with the ground as the
traction frame moves over the ground. The cutting unit has a weight
distribution or loading of an instantaneous nominal value when the
cutting unit is on level, flat ground. The cutting unit is
operatively coupled to the traction frame in a manner that permits
the cutting unit to roll about a horizontal longitudinal x axis and
to pitch about a horizontal transverse y axis to follow the ground
contour and to steer or yaw about a vertical z axis when the
traction frame is turning. The cutting unit is operatively coupled
to the traction frame such that the cutting unit steers or yaws
about a steering point that is located above and in front of the
cutting unit such that the cutting unit casters about this steering
point during turns of the traction frame. Finally, the cutting unit
is operatively coupled to the traction frame in a manner such that
the weight distribution or loading on the cutting unit remains
substantially at the instantaneous nominal value thereof even as
the cutting unit steers or yaws during turns of the vehicle.
[0013] Another aspect of this invention relates to a mower in which
the grass catcher and cutting unit both steer or yaw during turns
of the mower. This aspect is provided in a mower which comprises a
traction frame. A reel-type cutting unit is operatively coupled to
the traction frame in a manner that permits the cutting unit to
steer or yaw during turns of the traction frame. In addition, a
grass catcher is operatively coupled to the traction frame. The
grass catcher is located adjacent the cutting unit for receiving
grass clippings from the cutting unit. The grass catcher is
supported independently of the cutting unit such that the weight of
the grass catcher and accumulated grass clippings therein is not
substantially carried by the cutting unit. The grass catcher is
also operatively coupled to the traction frame in a manner that
permits the grass catcher to also steer or yaw during turns of the
traction frame.
[0014] Yet another aspect of this invention relates to a mower
having a level lift grass catcher. This aspect is provided in a
mower which comprises a traction frame. A reel-type cutting unit is
operatively coupled to the traction frame. A grass catcher is
operatively coupled to the traction frame, the grass catcher being
located adjacent the cutting unit for receiving grass clippings
from the cutting unit. The grass catcher is supported independently
of the cutting unit such that the weight of the grass catcher and
accumulated grass clippings therein is not substantially carried by
the cutting unit. A lift frame is attached to the grass catcher for
raising and lowering the grass catcher into and out of engagement
with the ground. The lift frame is pivotally connected to the
traction frame for rotation about a substantially horizontal pivot
axis on the traction frame such that the grass catcher is raised
and lowered relative to the ground as the lift frame pivots
upwardly and downwardly relative to the traction frame about the
substantially horizontal pivot axis on the traction frame. The lift
frame is further pivotally connected to the grass catcher such that
the grass catcher pivots about a substantially horizontal pivot
axis on the lift frame to adjust the orientation of the grass
catcher relative to the lift frame as the lift frame pivots
upwardly and downwardly relative to the traction frame. A tilt rod
extends between the traction frame and the grass catcher to
positively tilt the grass catcher forwardly as the lift frame
rises.
[0015] The above described aspects of this invention are just some
of the various aspects of this invention which exist. This
invention includes other aspects which have not been specifically
enumerated in this Summary of the Invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] This invention will be described hereafter in the Detailed
Description, taken in conjunction with the following drawings, in
which like reference numerals refer to like elements or parts
throughout.
[0017] FIG. 1 is a perspective view of a mower illustrating two
front cutting units with accompanying grass catchers according to
this invention, a rear cutting unit being present but being hidden
in FIG. 1 beneath the mower;
[0018] FIG. 2 is an enlarged perspective view of one of the cutting
units shown in FIG. 1 with the grass basket removed to illustrate
various portions of the support frame of the grass catcher;
[0019] FIG. 3 is a side elevational view of one of the cutting
units shown in FIG. 1 and its accompanying grass catcher;
[0020] FIG. 4 is a top plan view of one of the cutting units shown
in FIG. 1 and its accompanying grass catcher;
[0021] FIG. 5 is a side elevational view similar to FIG. 3 of one
of the cutting units shown in FIG. 1 and its accompanying grass
catcher, the phantom line illustration showing the cutting unit and
its accompanying grass catcher lowered into a cutting position and
the solid line illustration showing the cutting unit and its
accompanying grass catcher raised into a transport position;
[0022] FIG. 6 is a partial side elevational view of one of the
cutting units and its accompanying grass catcher taken along lines
6-6 in FIG. 4, illustrating the orientation of the grass catcher
transport bracket relative to a portion of the support frame of the
grass catcher when the cutting unit and its accompanying grass
catcher are lowered into a cutting position; and
[0023] FIG. 7 is a partial side elevational view similar to FIG. 6
of one of the cutting units and its accompanying grass catcher,
illustrating the orientation of the grass catcher transport bracket
relative to a portion of the support frame for the grass catcher
when the cutting unit and its accompanying grass catcher are raised
into a transport position.
DETAILED DESCRIPTION
[0024] A mower 2 is illustrated in the drawings which includes a
traction frame 4 that is movably supported on the ground by various
wheels 6. As depicted herein, mower 2 comprises a self-propelled
riding greensmower that is operated by an operator who sits on a
seat 8 carried on traction frame 4. Two front cutting units 10
extend forwardly from traction frame 4 and are located in advance
of the two front wheels 6 of mower 2. A similar center cutting unit
(not shown) is carried beneath traction frame 4 to overlap with
front cutting units 10 to cut the swath of grass that would
otherwise be left between front cutting units 10. At least one rear
wheel (not shown) is at the rear end of traction frame 4. At least
some or all of the front and rear wheels 6 are driven by the engine
or motor of mower 2 to propel traction frame 4, and hence cutting
units 10, over the ground. At least some of the wheels 6, typically
the rear wheel, are steerable to allow the operator to turn or
steer mower 2 using an input from steering wheel 9.
[0025] Referring to FIGS. 2 and 3, each cutting unit 10 preferably
is of the cutting reel type and includes a cutting unit frame 12
defined by spaced side plates 14 that are united or joined by
various cross members 16. A rotatable reel 18 and fixed bedknife
(not shown) are carried between side plates 14 with reel 18 serving
to sweep standing grass against a sharpened cutting edge on the
bedknife to cut the grass. As shown in FIG. 4, reel 18 is rotated
by a hydraulic motor 17 or the like mounted on one of the side
plates 14 and operated by any conventional hydraulic system carried
on traction frame 4, though reel 18 could also be powered by an
electric motor or a mechanical drive system or the like. Cutting
unit 10 includes front and rear support rollers 19 and 20 which
permit cutting unit 10 to be self-supporting on the ground and to
roll over the ground as mower 2 travels over the ground.
[0026] As will be described more completely below, cutting unit 10
is free to move relative to the ground about three axes of
movement. More specifically, cutting unit 10 can can roll about a
horizontal longitudinal axis x, can pitch about a horizontal
transverse axis y, and can yaw about a vertical axis z. The xyz
axes are depicted in FIG. 2. Movement of cutting unit 10 about the
x and y axes allows cutting unit 10 to float relative to the ground
to follow the contours of the surface it is cutting. Movement about
the z axis allows cutting unit 10 to steer or turn itself during
turns of mower 2.
[0027] The front of reel 18 above front support roller 19 is
preferably open all the way to the top of reel 18. Neither a
partial front shield in front of reel 18 nor a flexible seal
between the front shield and the grass catcher are used in this
preferred embodiment, though they could be used if so desired. Reel
18 rotates in a direction so that grass clippings will be
discharged forwardly from reel 18. A grass catcher 22 is located in
advance of cutting unit 10 to catch and retain these grass
clippings.
[0028] Grass catcher 22 includes a U-shaped or forked support frame
24 on which a grass basket 26 is releasably mounted. Support frame
24 includes two spaced, forwardly and downwardly extending legs 28
connected together at their upper ends by a transverse cross member
30. Each leg 28 includes an upwardly extending horn 32 which
interfits with a groove 34 located on each side of grass basket 26
to releasably hold grass basket 26 in place on support frame 24 in
a known manner. Grass basket 26 itself comprises a generally
enclosed container or receptacle including an open mouth 35 having
a lower lip 36, mouth 35 facing rearwardly when grass basket 26 is
mounted on support frame 24. Grass clippings are thrown from reel
18, by virtue of the rotation of reel 18, through mouth 35 of grass
basket 26 to be retained therein. Grass basket 26 can be
periodically removed from support frame 24 and dumped to empty
grass basket 26 of its accumulated grass clippings.
[0029] A lift and lower system is provided for lifting grass
catcher 22 and cutting unit 10 out of a lowered cutting position
and placing them in an elevated transport position. This lift and
lower system includes a lift frame 38 that is pivotally connected
at its rear end to a first substantially horizontal pivot axis 40
on a portion of traction frame 4. The forward end of lift frame 38
is joined to support frame 24. In addition, a lift arm 42 is also
pivotally coupled for rotation about axis 40. The rear end 43 of
lift arm 42 is connected to the piston rod 45 of a hydraulic
actuator 44.
[0030] Referring to FIGS. 3 and 5, lift arm 42 pivots in a
counter-clockwise direction about pivot axis 40 when the piston rod
45 of actuator 44 is extended out of the cylinder of actuator 44.
Lift arm 42 engages beneath a lift roller 41 on cutting unit 10 to
lift cutting unit 10 off the ground. This is depicted in FIG. 5. At
some point in the extension of piston rod 45, the rear end 43 of
lift arm 42 abuts against a stop 39 on the rear end of lift frame
38 to also begin pivoting lift frame 38 in a counter-clockwise
direction about pivot axis 40. Stop 39 can be adjusted so that lift
frame 38 begins rising before lift arm 42 has engaged lift roller
41, at approximately the same time as lift arm 42 engages lift
roller 41, or even after lift arm 42 has engaged lift roller 41. In
any event, lift frame 38 will similarly be pivoted in a
counter-clockwise direction after stop 39 is engaged by the rear
end 43 of lift arm 42 to raise grass catcher 22 out of its cutting
position closely adjacent the ground and into its elevated
transport position.
[0031] When piston rod 45 of hydraulic actuator 44 is retracted,
lift frame 38 and lift arm 42 correspondingly lower both grass
catcher 22 and cutting unit 10 back down into the lowered cutting
position shown in FIG. 3.
[0032] Lift frame 38 and its connection at one end to traction
frame 4 and at the other end to support frame 24 additionally
serves as the link which propels both cutting unit 10 and grass
catcher 22 forwardly as traction frame 4 moves forwardly. As
traction frame 4 moves forwardly, lift frame 38 directly pushes
support frame 24 and grass catcher 22 forwardly as well. Two pull
link arms 46 extend from the lower ends of legs 28 on support frame
24 and connect to each side of cutting unit 10 at approximately the
same height as the i centerline of front roller 19 by attaching to
extended end portions of the axle or support shaft of front roller
19. Ball joint connections are used on the rear ends of pull link
arms 46 where such arms 46 connect to cutting unit 10 to ensure
that cutting unit 10 can move in the x and y axes relative to the
ground. The forward ends of pull link arms 46 are pivotally coupled
to legs 28 of support frame 24. As support frame 24 is propelled
forwardly by lift frame 38, cutting unit 10 is similarly propelled
forwardly, albeit indirectly, by pull link arms 46.
[0033] U.S. Pat. No. 5,533,326 shows a prior art mower having a
steerable cutting unit with an integral lift frame/support frame
for the grass catcher. As described in the Background of the
Invention section of this application, a consequence of this design
is that grass catcher 22 does not steer or yaw during turns of
traction frame 4 as does cutting unit 10. Thus, the gap or distance
between reel 18 and lower lip 36 of mouth 35 of grass basket 26
does not remain constant during turns, leading to the possibility
of incomplete grass retention in grass basket 26 and/or contact
between grass basket 26 and cutting unit 10.
[0034] Mower 2 of this invention has a cutting unit 10 that steers
or yaws during turns and a grass catcher 22 which can also itself
yaw or steer during turns of traction frame 4 in a manner that
corresponds to the yawing or steering of cutting unit 10. Thus, the
gap or distance between reel 18 and lower lip 36 of mouth 35 of
grass basket 26 does not change during turns but remains
substantially constant. As a result, there is no danger that grass
basket 26 might contact cutting unit 10. Moreover, the grass
distribution into grass basket 26 remains the same without there
being an increased tendency for the clippings to miss grass basket
26 or to fall out of grass basket 26.
[0035] In a preferred embodiment, lift frame 38 is no longer
integral with support frame 24 as in the 326 patent. Instead, lift
frame 38 and support frame 24 are pivotally connected by a
substantially vertical pivot axis connection 48. Pivot axis
connection 48 is located forwardly of and above cutting unit 10 as
shown in FIG. 3 to form a high steering point for cutting unit 10.
Pivot axis connection 48 is also located on the longitudinal
centerline of cutting unit 10. Thus, cutting unit 10 will properly
trail behind pivot axis connection 48 and, during turns of mower 2,
will steer or yaw about pivot axis connection 48 in a caster type
manner.
[0036] As shown in the drawings, pivot axis connection 48 comprises
a U-shaped cradle 50 on the front end of lift frame 38. Cradle 50
overlies a central portion of cross member 30 of support frame 24.
A vertical pivot pin or rod 52 is installed through cradle 50. A
bushing 54 can be mounted on cross member 30 to receive pivot rod
52 and pivotally journal support frame 24 on pivot rod 52. Thus, by
virtue of pivot connection 48, support frame 24 can now steer or
yaw about the vertical or z-axis.
[0037] Because grass catcher 22 is now capable of yawing about the
substantially vertical axis defined by pivot rod 52, it is possible
for grass catcher 22 to be cocked or canted to one side at the time
the lift and lower system is activated by the operator. In other
words, there will be times when grass catcher 22 is pivoted to one
side or the other about pivot rod 52 with one leg 28 of support
frame 24 being further forward than the other leg 28 of support
frame 24 at the exact moment that the operator extends piston rod
45 of hydraulic actuator 44 to pivot lift frame 38 upwardly. If
this happens, the Applicants have discovered that cutting unit 10
will be tipped or tilted to one side when it is also raised. This
is not desirable.
[0038] Accordingly, this invention also preferably includes a grass
catcher transport bracket 56 that is bolted to one side of lift
frame 38 by a plurality of bolts 58. See FIG. 4. The forward
portion of grass catcher transport bracket 56 extends forwardly and
underlies a portion of cross member 30 of support frame 24. The
forward portion of transport bracket 56 has an upwardly facing
arcuate recess or groove 60 that is designed to mate with the
underside of cross member 30.
[0039] Normally, when grass catcher 22 is disposed in its lowered
cutting position, groove 60 in transport bracket 56 is spaced from
cross member 30 as shown in FIG. 6. However, as described below, if
the lift and lower system is activated and lift frame 38 is raised,
groove 60 in transport bracket 56 will eventually engage cross
member 30 as shown in FIG. 7. If grass catcher 22 is not straight
at this time such that cross member 30 is cocked or canted relative
to the position it would have if grass catcher 22 were straight,
one canted position being indicated in phantom in FIG. 6 compared
to the solid line position which indicates a straight orientation,
transport bracket 56 will cam support frame 24 in whatever
direction is required to cause cross member 30 to become seated
within groove 60. In effect, transport bracket 56 straightens
support frame 24 out so that the central portion of cross member 30
becomes perpendicular to a straight ahead direction of travel of
traction frame 4 and stabilizes grass catcher 22 in such
straightened condition. This allows cutting unit 10 to be suspended
evenly relative to grass catcher 22 without tilting to one side or
the other.
[0040] Obviously, for grass catcher transport bracket 56 to perform
the above noted function, there must be some relative motion
between transport bracket 56 and support frame 24 as the lift and
lower system is activated. This relative motion is provided by
another aspect of this invention, which will be described
hereafter, relating to keeping grass catcher 22 level as it lifts.
Namely, grass catcher 22 is tilted forwardly relative to lift frame
38 to maintain a level orientation as catcher 22 rises. As a
result, cross member 30 of support frame 24 is actually brought
into engagement with transport bracket 56 which can thus be affixed
to lift frame 38. However, transport bracket 56 could still be used
even if grass catcher 22 did not tip forwardly as part of a level
lift feature, but this would require that transport bracket 56 be
supported on some portion of traction frame 4 other than lift frame
38 and that transport bracket 56 be potentially reoriented to
ensure that groove 60 contacts cross member 30 at the end of its
rise to perform the grass catcher straightening function.
[0041] Consider now the operation of cutting unit 10 and grass
catcher 22 when cutting and when these components are placed in a
cutting position as shown in FIG. 3. When mower 2 is travelling
straight ahead, lift frame 38 propels support frame 24, and hence
grass catcher 22, forwardly and cutting unit 10 is also propelled
forwardly through pull link arms 46. Cutting unit 10 is free to
roll and pitch about the x and y axes to follow the ground contour
because of the ball joints at the rear of pull link arms 46 as well
as the pivotal connections at the front of pull link arms 46.
[0042] When mower 2 turns to one side or the other, the ground
acting on cutting unit 10 imposes side forces on the cutting unit
which forces want to steer or yaw the cutting unit about the z axis
to accomodate the turn. This steering or yawing is now permitted in
mower 2 of this invention, even with the use of dual pull link arms
46, because of the inclusion of the substantially vertical pivot
axis connection 48. Effectively, cutting unit 10 is able to caster
or turn itself about connection 48. There is no active steering of
cutting unit 10, but the steering that is involved is purely a
consequence of the natural castering that is now able to take place
about vertical pivot axis connection 48.
[0043] As cutting unit 10 turns, the dual pull link arms 46 also
act on support frame 24 to similarly and correspondingly steer or
yaw grass catcher 22. Thus, in every turn of mower 2, both cutting
unit 10 and its associated grass catcher 22 steer or yaw together
in the same direction and in approximately the same amount about
pivot connection 48.
[0044] The use of dual pull link arms 46 which are spaced to either
side of the longitudinal centerline of cutting unit 10, instead of
a single pull link arm that is centered on the centerline of
cutting unit 10 as shown in the 326 patent, ensures that grass
catcher 22 and cutting unit 10 steer together and maintain a
constant clearance between lip 36 and reel 18. Pull link arms 46
are adjustable in length to be able to adjust or vary this
clearance, but once adjusted the length of pull link arms 46
remains constant during operation of mower 2 until manually
readjusted. Since pull link arms 46 have a nominally fixed length
that does not vary during operation of mower 2, pull link arms 46
cause grass catcher 22 to turn similarly to cutting unit 10. If
there is some looseness or play in the length of pull link arms 46
due to manufacturing tolerances or wear as mower 2 ages, there may,
at times, be a slight mismatch in the turning of grass catcher 22
compared to cutting unit 10, but overall grass catcher 22 turns
approximately the same amount as does cutting unit 10.
[0045] Pull link arms 46 transmit force between support frame 24
and cutting unit 10 only along the longitudinal x axis to pull or
propel cutting unit 10, but do not transmit force along the y or z
axes. As in the 326 patent, pull link arms 46 preferably connect to
cutting unit 10 along the longitudinal centerline of front roller
19. In addition, as noted earlier, pull link arms 46 also are
pivotally coupled by ball joints to cutting unit 10 and by
additional pivots to support frame 24. Thus, when mower 2
negotiates a turn and cutting unit 10 steers or yaws about the z
axis defined by pivot axis connection 48, the weight distribution
or loading on cutting unit 10, for example the down force measured
on the edge of front roller 19 on the inside of the turn, does not
substantially change from the instantaneous nominal value it would
have had when mower 2 was travelling straight on flat ground. In
other words, if 20 pounds of down force had been present on that
side of front roller 19 immediately before the turn, approximately
20 pounds of down force would still be present on that side of
front roller 19 during the turn, thereby preventing cutting unit 10
from tending to dig or roll that side of the cutting unit 10 into
the ground and gouging or scuffing the turf. This desirable result
is accomplished in mower 2 of this invention even with a high
steering point located above cutting unit 10 as represented by
pivot axis connection 48, which is obviously easier to accomplish
from a structural standpoint than using a low steering point as in
the 326 patent.
[0046] As just noted, grass catcher 22 is desirably kept level as
it rises into its transport position. This preferably should be
done in a foolproof, reliable manner to ensure a level lift for
grass catcher 22. This will keep the grass clippings in grass
basket 26 and prevent them from spilling or dribbling out.
[0047] In addition to being pivotally mounted by the substantially
vertical pivot axis connection 48 to permit steering or yawing
relative to traction frame 4, as already described, grass catcher
22 of this invention is additionally mounted for pivoting about a
substantially horizontal pivot axis 62 on the front end of lift
frame 38. U-shaped cradle 50 that forms part of pivot connection 48
is additionally provided with a rearwardly extending clevis formed
by spaced, parallel ears 64. These ears 64 are pivotally mounted on
a substantially horizontal pivot rod 66 carried on the front end of
lift frame 38. Thus, support frame 24 can pivot about horizontal
pivot axis 62 as cradle 50 pivots about pivot rod 66, and further
can pivot about a vertical axis as support frame 24 pivots about
vertical pivot rod 52 carried by cradle 50.
[0048] One of the ears 64 that forms the pivot receiving clevis on
U-shaped cradle 50 has an extended upper portion 68 that sticks up
above lift frame 38. A tilt rod 70 has a forward end pivotally
secured to this extended upper portion 68 of ear 64 as shown by a
pivot axis 72 and a rearward end pivotally secured to traction
frame 4 as shown by a pivot axis 74. Tilt rod 70 is arranged and
configured to pivot or tilt support frame 24 forwardly relative to
lift frame 38 about horizontal pivot rod 66 as support frame 24 is
lifted by the lift and lower system. This forward pivoting motion
of support frame 24, which is indicated by the arrows A in FIG. 7,
is chosen to be just the right amount to maintain grass catcher 22
level as it is lifted. If desired, tilt rod 70 could also be
configured to cause grass catcher 22 to even tip slightly forwardly
in its raised position. In either case, keeping grass catcher 22
level or tipping it forwardly as it lifts will ensure that the
grass clippings are retained in grass basket 26 and will not fall
out of grass basket 26. Thus, tilt rod 70 at least keeps or
maintains the grass catcher level as it lifts which means that
grass catcher 26 is either kept substantially level or is tipped
forwardly during lifting.
[0049] The level lift system just described for grass catcher 22
works in a positive and foolproof manner. It does not rely on
gravity or the weight distribution of the grass clippings within
grass basket 26. Tilt rod 70 will as a consequence of the geometry
of the parts and of the lifting action provided by the lift and
lower system always pivot grass catcher 22 to keep it level. Thus,
the operator need not fear that the grass clippings will fall or
dribble out of grass basket 26 even in the transport position of
grass catcher 22.
[0050] Moreover, the level lift system just described works by
tilting support frame 24 of grass catcher 22. Since support frame
24 is connected by pull link arms 46 to cutting unit 10, tilting
support frame 24 also tilts cutting unit 10 similarly to maintain
the distance between cutting unit 10 and grass catcher 22 as the
two lift.
[0051] Various modifications of this invention will be apparent to
those skilled in the art. While the various features of this
invention comprising a steerable grass catcher 22, i.e. a grass
catcher 22 that can yaw about a substantially vertical pivot axis,
and a level lift system for grass catcher 22 are preferably used
together on the same grass catcher, these features could also be
used separately. In other words, one could have a mower with a
steerable grass catcher 22 without also attempting to keep this
grass catcher level, and vise versa. In addition, while mower 2 has
been shown as comprising a riding greensmower, mower 2 could also
be one where the operator walks behind traction frame 4 and is not
seated thereon.
[0052] Moreover, the number of cutting units and associated grass
catchers could obviously vary as long as at least one cutting unit
and one grass catcher are used on traction frame 4. Reference in
any of the claims to "a" cutting unit or "a" grass catcher simply
means that at least one cutting unit or at least one grass catcher
is being claimed but is not meant to limit the claim to covering
only a single cutting unit or a single grass catcher. Each of the
cutting units 10 and grass catchers 22 attached to traction frame 4
as described herein, namely both of the front as well as the center
cutting unit and their associated grass catchers, are generally
identical so that the foregoing description applies equally to each
of the cutting units 10 and grass catchers 22.
[0053] Accordingly, the invention is to be limited only by the
appended claims.
* * * * *