U.S. patent application number 10/796558 was filed with the patent office on 2005-02-24 for lawn mower.
This patent application is currently assigned to KUBOTA CORPORATION. Invention is credited to Asahara, Masato, Esaki, Yoshiyuki, Fujiwara, Osami, Minoura, Akira, Samejima, Kazuo, Togoshi, Yoshikazu.
Application Number | 20050039430 10/796558 |
Document ID | / |
Family ID | 34114152 |
Filed Date | 2005-02-24 |
United States Patent
Application |
20050039430 |
Kind Code |
A1 |
Samejima, Kazuo ; et
al. |
February 24, 2005 |
LAWN MOWER
Abstract
A lawn mower comprises a blade drive shaft with a blade
rotatably mounted inside a mower deck supported by a vehicle body,
a blower unit including a cylindrical blower housing connected to a
grass clippings discharging section provided in a side end region
of the mower deck, a vertical drive shaft having a shaft portion
with vanes attached thereto inside the blower housing and a shaft
portion extending upward through the blower housing, and a
discharging sleeve projecting rearwardly along an outer tangent
line of the blower housing, a grass collecting apparatus mounted
rearwardly of the vehicle body, a duct for allowing the discharging
sleeve to communicate with the grass collecting apparatus, and a
belt-type blower driving mechanism for driving the vertical drive
shaft of the blower unit. The belt-type blower driving mechanism
includes an intermediate vertical shaft disposed rearwardly of the
blower housing, and a belt transmission unit for transmitting power
from the blade drive shaft to the vertical drive shaft through the
intermediate vertical shaft.
Inventors: |
Samejima, Kazuo; (Osaka,
JP) ; Togoshi, Yoshikazu; (Osaka, JP) ;
Asahara, Masato; (Osaka, JP) ; Esaki, Yoshiyuki;
(Osaka, JP) ; Minoura, Akira; (Osaka, JP) ;
Fujiwara, Osami; (Osaka, JP) |
Correspondence
Address: |
Russell D. Orkin
WEBB ZIESENHEIM LOGSDON ORKIN & HANSON, P.C.
700 Koppers Building
436 Seventh Avenue
Pittsburgh
PA
15219-1818
US
|
Assignee: |
KUBOTA CORPORATION
Osaka
JP
|
Family ID: |
34114152 |
Appl. No.: |
10/796558 |
Filed: |
March 9, 2004 |
Current U.S.
Class: |
56/320.2 |
Current CPC
Class: |
A01D 43/077 20130101;
A01D 69/00 20130101 |
Class at
Publication: |
056/320.2 |
International
Class: |
A01D 061/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 18, 2003 |
JP |
PAT. 2003-294350 |
Claims
What is claimed is:
1. A lawn mower comprising: a mower deck supported by a vehicle
body; a blade drive shaft with a blade rotatably mounted inside the
mower deck; a grass clippings discharging section provided in a
side end region of the mower deck; a blower unit including a
cylindrical blower housing connected to the grass clippings
discharging section, a vertical drive shaft having a shaft portion
with vanes attached thereto inside the blower housing and a shaft
portion extending upward through the blower housing, and a
discharging sleeve projecting rearwardly along an outer tangent
line of the blower housing; a grass collecting apparatus mounted
rearwardly of the vehicle body; a duct for allowing the discharging
sleeve to communicate with the grass collecting apparatus; a
belt-type blade driving mechanism mounted above a top wall of the
mower deck for driving the blade drive shaft; and a belt-type
blower driving mechanism for driving the vertical drive shaft of
the blower unit by utilizing power transmitted from the belt-type
blade driving mechanism, the blower driving mechanism including an
intermediate vertical shaft disposed rearwardly of the blower
housing, and a belt transmission unit for transmitting power from
the blade drive shaft to the vertical drive shaft through the
intermediate vertical shaft.
2. A lawn mower as claimed in claim 1, wherein the intermediate
vertical shaft is mounted in a corner area defined by an outer
peripheral wall of the blower housing and the discharging
sleeve.
3. A lawn mower as claimed in claim 2, wherein the belt
transmission unit includes belt pulleys mounted on the blade drive
shaft and the intermediate vertical shaft, a first belt wound
around the pulleys, and a first tension clutch switchable between a
disengaging position for breaking the power transmission ability of
the first belt and an engaging position for maintaining the power
transmission ability of the first belt.
4. A lawn mower as claimed in claim 3, wherein the belt
transmission unit includes belt pulleys mounted on the vertical
drive shaft and the intermediate vertical shaft, a second belt
wound around the pulleys, and a second tension clutch switchable
between a disengaging position for breaking the power transmission
ability of the second belt and an engaging position for maintaining
the power transmission ability of the second belt.
5. A lawn mower as claimed in claim 4, wherein the tension pulley
of the first tension clutch and the tension pulley of the second
tension clutch are displaceable about a common pivotal axis.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a lawn mower adapted to
collect grass clippings cut by a mower unit in a grass collecting
apparatus mounted rearwardly of a vehicle body.
[0003] 2. Description of the Related Art
[0004] A conventional lawn mower of the above-noted type is known
from U.S. Pat. No. 5,224,327 and Japanese Patent Application
"Kokai" No. 8-322355, for example, which comprises a mower unit
including a mower deck having bar blades driven to rotate about
vertical axes and a grass clippings discharge outlet formed in a
side end of the mower deck, the mower unit being attached to a
vehicle body to be vertically movable, a grass collecting apparatus
mounted rearwardly of the vehicle body, and a blower unit mounted
above the grass clippings discharge outlet of the mower deck to be
driven by a vertical shaft and operatively connected to a blade
driving line, wherein grass clippings discharged from the grass
clippings discharge outlet are forcibly transported to the grass
collecting apparatus through the blower unit and a duct.
[0005] The conventional lawn mower noted above employs a belt
transmission mechanism in which a blade drive shaft of the bar
blade positioned closest to the grass clippings discharge outlet is
interlocked with a lower end portion of an intermediate vertical
shaft by winding a belt thereon while an upper end portion of the
intermediate vertical shaft is interlocked with an impeller drive
shaft projecting upwardly of a blower housing by winding a belt
thereon, thereby to transmit power taken from the blade driving
line provided above the mower deck to a blower input portion
provided in a higher position. With this arrangement, however, the
relay intermediate vertical shaft is mounted forwardly of the
blower housing, as a result of which pulleys provided in the upper
and lower end portions of the intermediate vertical shaft
disadvantageously project to a large extent forwardly of the blower
housing.
[0006] A blower drive mechanism including the intermediate vertical
shaft is incorporated in the blower unit as one unit and attachable
to and detachable from the mower deck. As described above, the
intermediate vertical shaft is mounted forwardly of the blower
unit, which increases a dimension from a front end of the blower
drive mechanism to a rear end of a discharging sleeve projecting
rearwardly of the blower housing. Consequently, such a blower unit
is cumbersome to handle when attached to or removed from the mower
deck and requires a large storage space when removed.
SUMMARY OF THE INVENTION
[0007] The object of the present invention is to provide a compact
arrangement of the blower unit and blower driving mechanism to
facilitate handling and storage thereof in order to solve the
above-noted problems of the prior art.
[0008] In order to fulfill the above object, a lawn mower according
to the present invention comprises a mower deck supported by a
vehicle body, a blade drive shaft with a blade rotatably mounted
inside the mower deck, a grass clippings discharging section
provided in a side end region of the mower deck, a blower unit
including a cylindrical blower housing connected to the grass
clippings discharging section, a vertical drive shaft having a
shaft portion with vanes attached thereto inside the blower housing
and a shaft portion extending upward through the blower housing,
and a discharging sleeve projecting rearwardly along an outer
tangent line of the blower housing, a grass collecting apparatus
mounted rearwardly of the vehicle body, a duct for allowing the
discharging sleeve to communicate with the grass collecting
apparatus, a belt-type blade driving mechanism mounted above a top
wall of the mower deck for driving the blade drive shaft, and a
belt-type blower driving mechanism for driving the vertical drive
shaft of the blower unit by utilizing power transmitted from the
belt-type blade driving mechanism. The blower driving mechanism
includes an intermediate vertical shaft disposed rearwardly of the
blower housing, and a belt transmission unit for transmitting power
from the blade drive shaft to the vertical drive shaft through the
intermediate vertical shaft.
[0009] In this arrangement, the intermediate vertical shaft
constituting a core element of the blower driving mechanism is
disposed in a dead zone defined rearwardly of the blower housing,
which prevents the blower driving mechanism from putting any
spatial pressure on other elements and reduces the fore-and-aft
dimensions of the blower unit per se having the blower driving
mechanism integrated therewith, compared with the conventional
arrangement. Thus, the blower unit is easily attached to or
detached from the mower deck with the benefits of compactness in
the fore-and-aft dimensions of the blower unit having the blower
driving mechanism integrated therewith, which also reduces the
storage space for the removed blower unit.
[0010] Further, for providing an optimal arrangement of the
intermediate vertical shaft constituting the core element of the
blower driving mechanism, it is proposed that the intermediate
vertical shaft is mounted in a corner area defined by an outer
peripheral wall of the blower housing and the discharging sleeve.
With this arrangement, the blower driving mechanism is free from
interference with the other elements, while quite a rational
arrangement is provided for the blower unit and the blower driving
mechanism.
[0011] According to one preferred embodiment of the present
invention, the belt transmission unit includes belt pulleys mounted
on the blade drive shaft and the intermediate vertical shaft, a
belt wound around the pulleys, and a tension clutch switchable
between a disengaging position for breaking the power transmission
ability of the belt and an engaging position for maintaining the
power transmission ability of the belt. With this arrangement, in
attaching and detaching the blower unit having the blower driving
mechanism integrated therewith to/from the mower deck, the belt
wound between the blade drive shaft and the intermediate vertical
shaft can be maintained in a loose state by maintaining the tension
clutch in the disengaging position. Also, when the mower unit is
driven idle for cleaning the interior of the mower deck, the
tension clutch is switched to the disengaging position, which
prevents the blower unit from being driven unnecessarily and allows
only the mower unit to be driven.
[0012] Other features and advantages of the present invention will
be apparent from the following detailed description of the
preferred embodiments to be taken with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a side elevation of a lawn mower;
[0014] FIG. 2 is a plan view of the lawn mower;
[0015] FIG. 3 is a plan view of a mower unit;
[0016] FIG. 4 is a plan view of a blower unit in cross section;
[0017] FIG. 5 is a side view of the blower unit in vertical
section;
[0018] FIG. 6 is a rear view of the blower unit in vertical
section;
[0019] FIG. 7 is a side view of a principal portion of the blower
unit in vertical section;
[0020] FIG. 8A and FIG. 8B are plan views of a tension clutch;
[0021] FIG. 9 is a side view of a grass collecting apparatus in
vertical section;
[0022] FIG. 10 is a rear view of the grass collecting apparatus in
vertical section;
[0023] FIG. 11 is a side view showing part of the grass collecting
apparatus in vertical section with a guide cover being opened;
[0024] FIG. 12 is an exploded perspective view of the grass
collecting apparatus; and
[0025] FIG. 13 is a side elevation of the lawn mower with the grass
collecting apparatus being opened.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] FIG. 1 and FIG. 2 show a lawn mower relating to the present
invention in side elevation and in plan view, respectively. The
lawn mower comprises a running vehicle body 3 having a right and
left pair of caster-type front wheels 1 and a right and left pair
of rear drive wheels 2. A mower unit M is suspended from the
underside of the running vehicle body 3 between the front and rear
wheels through a right and left pair of four-point linkage
mechanisms 4 each having a front link 4a, a rear link 4b and a
lower connecting link 4c. The linkage mechanisms are vertically
movable by a hydraulic cylinder 5 thereby to move the mower unit M
vertically in a generally parallel movement. A motor section 7
housing an engine 6 projects rearwardly of the rear wheels 2. A
grass collecting apparatus 8 for collecting grass clippings is
mounted across the motor section 7. A driver's seat 9 is disposed
forwardly of the motor section 7, and a gate-shaped rollover
protective structure (ROPS) 10 is mounted between the driver's seat
9 and the motor section 7.
[0027] A detailed description of the vehicle construction is
omitted here. Output from the engine 6 is inputted to a counter
casing 11 and divided into a propelling line and a working line.
Power in the propelling line is inputted to an unillustrated right
and left pair of hydraulically operable stepless hydrostatic
transmissions (HSTs) provided at opposite sides of the counter
casing 11. Power output in varied speeds is transmitted from the
respective HSTs to the right and left rear wheels 2 individually
through reduction cases 12. The stepless hydrostatic transmissions
for driving the right and left rear wheels 2 are shiftable by a
pair of right and left propelling levers 13 individually which are
provided at opposite sides of the driver's seat 9 to be rockable
back and forth, thereby to steplessly change forward and backward
speeds of the right and left rear wheels 2 independently. The right
and left propelling levers 13 are operable to selectively establish
a forward or rearward straight running state, a turning state with
the right and rear wheels 2 driven at different speeds, a pivot
turn with one of the rear wheels 2 standing still, and a spin turn
with the right and left rear wheels 2 driven in opposite
directions. The branched drive power for the working line is
outputted forwardly from a PTO shaft 14 projecting from a lower
front portion of the counter casing 11 to be transmitted to the
mower unit M.
[0028] As illustrated in FIG. 3, the mower unit M includes a mower
deck 15 opening downward and including three bar blades 16, 17 and
18 mounted therein to be rotatable about vertical axes. These
blades are arranged in juxtaposition and shaft-supported by the
mower deck. The mower deck 15 is constructed as a flat deck with an
upper wall having a uniform height over the entire deck. A
discharge section forming a discharge outlet "d" is provided at a
right end portion of the deck.
[0029] The working drive power taken from the PTO shaft 14 is
transmitted to a bevel gear casing 19 mounted on a central top
surface of the mower deck 15 through a flexible and extendible and
contractible shaft transmission mechanism 20. The rotary power
converted to rotation about a vertical axis in the bevel gear
casing 19 is transmitted to a rotary shaft 17a of the central bar
blade 17. The rotary shaft 17a and rotary shafts 16a and 18a of the
right and left bar blades 16 and 18 are interlocked with each other
through a belt 21 wound thereon. All of the bar blades 16, 17 and
18 are rotated in the same direction (clockwise as viewed from
above) so that front halves of loci of rotation of the bar blades
16, 17 and 18 are directed toward the discharge outlet "d".
Further, freely rotatable wheels (anti-scalp rollers) 22 are
provided around the mower deck 15 for riding obstacles.
[0030] A blower unit B is attached to the right end portion of the
mower deck 15 of the mower unit M, as described hereinafter, to be
driven for forcing grass clippings discharged from the discharge
outlet "d" toward the grass collecting apparatus 8 at the rear of
the vehicle body.
[0031] As shown in FIGS. 3 through 7, the blower unit B includes a
blower housing 31 connected to the discharge outlet "d" of the
mower deck 15, and an impeller 32 supported by an upper wall of the
blower housing 31 to be rotatable about a vertical axis. The blower
housing 31 is connected and fixed to a support frame 33 U-shaped in
plan view and mounted on the right end portion of the mower deck
15. The support frame 33 is connected at front and rear ends
thereof to connecting elements 34 fixed to the deck through
connecting pins 35 to be detachable by removing the connecting pins
35 to separate the blower unit B from the discharge outlet "d" for
the purpose of maintenance. The support frame 33 connecting and
supporting the blower housing 31 also serves as a guard frame
surrounding the blower housing 31.
[0032] An intermediate vertical shaft 36 is mounted at the rear of
the support frame 33. A belt 39 is wound in tension between a
pulley 37 mounted on a lower end portion of the intermediate
vertical shaft 36 and a pulley 38 mounted on an upper end portion
of the blade drive shaft 18a of the right-end bar blade 18, while a
belt 43 is wound in tension between a pulley 40 mounted on an upper
end portion of the intermediate vertical shaft 36 and a pulley 42
of an impeller drive shaft 41 protruding from a top surface of the
blower housing 31. Thus, the blower unit B is driven by the power
taken from the blade driving line.
[0033] The belt 39 for operatively interconnecting the blade drive
shaft 18a and the intermediate vertical shaft 36 is provided in a
position higher than the blade driving belt 21. As shown in FIG. 1,
the lower connecting link 4c of the linkage mechanism 4 is inclined
to extend upwardly and rearwardly to be connected to the mower deck
15 so that the pulley 38 and the belt 39 are accommodated, free
from interference, in a vertically enlarged space defined between a
rear portion of the lower connecting link 4c of the right-side
linkage mechanism 4 and the upper surface of the deck.
[0034] The belt 29 wound around and operatively interconnecting the
blade drive shaft 18a and the intermediate vertical shaft 36 and
the belt 43 wound around and operatively interconnecting the
intermediate vertical shaft 36 and the impeller drive shaft 41 are
pressed tight by tension rollers 44 and 45, respectively. The
tension roller 44 acting on the belt 39 acts also as a tension
clutch 46 for breaking and establishing power transmission from the
blade drive shaft 18a to the intermediate vertical shaft 36. More
particularly, as shown in FIGS. 8A and 8B, the tension roller 44 is
carried by a tension arm 47 swingable about a pivotal shaft Pa
disposed on the blower unit. The tension arm 47 is operatively
connected to a switching control lever 48 mounted on the blower
unit to be selectively swingable about a control shaft Pb disposed
on the blower unit through a curved link 49 and a spring 50. The
switching control lever 48 is pivotable beyond a dead point to be
selectively maintained between an engaging position for pressing
the tension roller 44 against the belt 39 by a tensile force of the
spring 50 and a disengaging position for moving the tension roller
44 sufficiently away from the belt 39 to relieve the tension. The
tension roller 45 is also carried by a tension arm 52 supported to
be swingable about the pivotal shaft Pa and pivotably urged in a
fixed direction by a spring 51, thereby to constantly maintain the
belt 43 under tension.
[0035] As described above, the blower driving mechanism including
the intermediate vertical shaft 36, the tension arms 47 and 52, the
belt 43, the switching control lever 48 and the like is
incorporated in the blower unit B as an integral part thereof In
order to detach the blower unit from the mower deck 15, the belt 39
is removed from the pulley 38 of the blade drive shaft 18a to
remove the connecting pins 35 with the tension clutch 46 being
maintained in the disengaging position. On the other hand, a
reversed process is carried out to attach the blower unit to the
mower deck 15, and then the belt 39 is wound around the pulley 38
to switch and maintain the tension clutch 46 in the engaging
position.
[0036] The intermediate vertical shaft 36 is mounted upright and
positioned in a corner formed inwardly of the vehicle body and
enclosed by a discharge sleeve 31a projecting rearwardly from an
outer peripheral position of the blower housing 31 and a circular
outer periphery of the blower housing 31. Thus, the blower drive
mechanism is accommodated in the interior of the support frame 33
compactly in both the fore-and-aft and sideways directions.
[0037] A cylindrical duct 53 is detachably inserted in and
connected to the discharge sleeve 31a of the blower housing 31 in
the blower unit B installed and driven as set forth above for
guiding and supplying the grass clippings forcibly discharged by
the impeller 32 to the grass collecting apparatus 8 mounted on the
rear of the vehicle body.
[0038] The grass collecting apparatus 8 is adapted to collect the
grass clippings transported through the duct 53 in two grass
catching bags 60 mounted on opposite sides of the motor section 7.
The construction thereof will be described hereinafter.
[0039] Grass catcher frames 61 made of pipes are connected through
pins between lateral post portions of the rollover protective
structure 10 and engine mounting frames 23 below the motor section
7. A cross frame 61a extends between upper portions of the grass
catcher frames 61, and four bag supporting arms 62 extend rearward
from the cross frame 61a. A right and left pair of bag connecting
sections 63 are distributed to opposite sides of the motor section
7, each defined by the two bag supporting arms 62. The duct 53 is
detachably connected at a rear end thereof to the grass collecting
apparatus at a right-side position thereof, while a guide cover 65
with an entire area thereof opening downward is mounted on the
grass catcher frames 61 to be vertically pivotable about a pivotal
point "c" between an open position and a closed position.
[0040] Each of the grass catching bags 60 is a rectangular bag made
of sewn cloth of high air permeability. A core frame 66 made of a
metal bar is sewn to an upper opening edge of the bag to maintain
the opening edge of the bag in a rectangular shape. The opening
edge maintained in its shape by the core frame 66 is placed on top
surfaces of the two bag supporting arms 62 in each bag connecting
section 63 and supported by a lower edge portion of the closed
guide cover 65, thereby to prevent lifting of the grass catching
bag 60.
[0041] The two sets of bag supporting arms 62 constituting the
right and left bag connecting sections 63 are provided in a
position slightly higher than an engine hood 24 in the motor
section 7. A bottom plate 67 extends between the two inner bag
supporting arms 62 so as to overlap the engine hood 24. The bottom
plate 67 forms a tunnel passage 68 within the guide cover 65 when
the latter is lowered, to interconnect upper spaces in the right
and left bag connecting sections 63. The grass clippings fed into
the right side of the guide cover 65 through the duct 52 are guided
by the guide cover 65 to the right and left grass catching bags 60.
Air flows entraining the grass clippings and blown into the guide
cover 65 are directed to an air discharge passage 70 through a
mesh-like air discharge outlet 69 formed on an inner surface of a
rear portion of the guide cover 65, thereby to be discharged
rearwardly and downwardly.
[0042] For inspection and maintenance of the motor section 7, as
illustrated in FIG. 13, the pin-connection between the grass
catcher frames 61 and the rollover protective structure frame 10 is
released, and the entire grass catcher frames 61 is swung
rearwardly about a pin connecting point "e" connecting the frames
to the engine mounting frames 23, thereby to produce an open space
around the motor section 7.
* * * * *