Mower mounted on vehicle

A mower comprising a mower frame attached to the bottom of a vehicle body, cutting blades rotatably supported by vertical shafts on the mower frame, a drive assembly on the frame for rotating the blades, arms supported on the frame and pivotally movable upward or downward, gauge members supported by the free ends of the pivotal arms, an operating member operatively connected to the pivotal arms for pivotally moving the arms, and locking means for disengageably holding the operating member. The mower frame is upwardly or downwardly movable by the movement of the pivotal arms with the gauge members in engagement with the ground to position the cutting blades at the desired level. The blades are retainable at this level by the locking means.

BACKGROUND OF THE INVENTION 
This invention relates to a mower mounted on a tractor or like vehicle. 
As is well known, a rotary mower attached to the bottom of the frame of a 
vehicle, such as a tractor, performs the contemplated work while the 
vehicle travels on the ground. The mower is equipped with grass cutting 
rotary blades supported by the frame of the mower and each rotatable about 
a vertical shaft and with gauge members for maintaining the cutting blades 
at a constant level above the ground during travel. 
On the other hand, the position of the mower frame is vertically adjustable 
relative to the gauge members to enable the blades to cut grass at an 
altered constant level. 
With such mowers heretofore known, the cutting blades are adjusted to the 
desired level along with the mower frame by shifting the gauge members 
upward or downward with replacement of pins or bolts. Thus it is not easy 
to alter the grass cutting height, while it is impossible to immediately 
vary the cutting height during operation. Further when the mower is 
provided with a gauge member at each end of the mower frame, it is 
impossible to adjust both the gauge members at the same time, so that the 
gauge members must be adjusted individually by a cumbersome procedure. 
For the adjustment of the level of the mower frame, the mower frame is 
usually provided with pivotal arms each of which is upwardly or downwardly 
movable about a lateral pin and has a vertical rod supporting a gauge 
member freely turnably about the rod. Thus the cutting blades are made 
adjustable to the desired level by the pivotal movement of the pivotal 
arms. Although this arrangement is simple, the movement of the pivotal 
arms about the lateral pins for altering the cutting height also moves the 
vertical rods to an inclined position. With the vertical rods thus 
inclined, the gauge members have difficulties in retaining their stable 
forwardly oriented position, failing to accurately follow the vehicle, 
such as tractor, and entailing operational troubles. Further when the 
gauge member idly turns about the vertical rod in an inclined position, 
the cutting blades on the mower frame, as well as the frame per se, will 
be brought to an altered level, consequently producing irregularities in 
the cutting height and undesirable work results. 
In the case where the mower comprises an upwardly or downwardly movable 
frame attached to the bottom of the body of a vehicle, a drive assembly 
for receiving power from the drive source of the vehicle to drive the 
cutting blades, and a transmission box mounted on the mower frame as 
projected therefrom and provided for the drive assembly, the lift of the 
mower is limited because the transmission box will come into contact with 
the vehicle body, consequently limiting the cutting height. It is then 
impossible to hold the mower raised at a sufficient distance from the 
ground during the travel of the vehicle. The mower is therefore likely to 
strike some obstacle, or the cutting blade will contact the ground and 
become damaged when it is moved upward or downward for adjustment or when 
it is in operation. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a mower comprising cutting 
blades and a mower frame supporting the blades which are adjustable by a 
common operating member to the desired cutting level with ease even when 
the mower frame is provided at its opposite ends with gauge members, the 
operating member being lockable to hold the cutting blades at the desired 
adjusted level a constant distance above the ground and to maintain a 
uniform cutting height. 
Another object of the invention is to provide a mower equipped with locking 
means which is simple and reliable to operate to hold the cutting blades 
in a position a constant distance above the ground and to maintain a 
uniform cutting height. 
Another object of the invention is to provide a mower comprising pivotal 
arms supported on the frame of the mower and pivotally movable upward or 
downward, gauge members supported by vertical rods on the free ends of the 
pivotal arms and idly turnable about the vertical rods, the cutting blades 
upwardly or downwardly movable by the movement of the pivotal arms with 
the gauge members in engagement with the ground, the vertical rods being 
retainable in the same vertical position when the cutting blades are moved 
upward or downward to hold the cutting blades at an adjusted level without 
shifting even when the gauge member idly turns about the vertical rod, the 
mower thus assuring a uniform cutting height while permitting the gauge 
member to smoothly and accurately follow the travel of the vehicle on 
which the mower is mounted. 
Another object of the invention is to provide a mower mounted on a vehicle 
and comprising cutting blades and a cutting blade drive assembly mounted 
on the frame of the mower and including a transmission box, the 
transmission box being arranged not to interfere with the body of the 
vehicle when the cutting blades are moved upward or downward for 
adjustment, the mower thus being made liftable to a higher level to assure 
a sufficiently high cutting height and thereby rendered operable with high 
stability free of damage when the vehicle travels along with the mower 
attached thereto. 
Still another object of the invention is to provide a mower including 
cutting blades which are protected from the ground free of contact 
therewith when the blades are moved upward or downward for adjustment or 
when the blades are in operation for cutting down grass or the like.

DETAILED DESCRIPTION OF THE INVENTION 
FIGS. 1 to 7 show a first embodiment of the invention as attached to a 
vehicle which is a tractor. The body 1 of the tractor is provided with 
front wheels 2, rear wheels 3, a bonnet 4, a steering wheel 5 and a 
driver's seat, and further has steps 7 and mower mounting brackets 8 which 
are provided on both sides of the body 1 approximately in the midportion 
thereof. Detachably mounted on the body 1 at a front lower portion thereof 
is a front power take-off unit 9 coupled to a front PTO shaft projecting 
forward from the engine. 
Attached to the bottom of the body 1 is the present embodiment, namely, 
mower 10 consisting essentially of a mower frame 11, cutting blades 12 
supported by the mower frame 11 and each rotatable about a vertical shaft, 
and gauge members 13 for adjusting the level of the mower frame 11. As 
seen in FIG. 2, the mower frame 11 has a front portion resembling an arrow 
head when seen in plan and opposite ends extending outward sidewise of the 
tractor to provide a slightly elevated discharge guide channel 14. The 
front portion extends into a stepped lower horizontal rear portion. A 
transmission box 16 is fixedly disposed on the mower frame in the center 
to the front of the horizontal portion as seen in FIG. 4. The box 16 
attached to the frame by a stay 15 comprises a vertical hollow cylinder 17 
and a forward hollow cylinder 18 in a T-shaped arrangement. 
The vertical cylinder 17 has a lower end at some distance above the mower 
frame 11. A main shaft 19 for the cutting blades 12 is housed in the 
cylinder 17 as supported at upper and lower two portions, extends through 
a bearing case 20 fixed to the mower frame 11 and projects downward into 
the frame 11. One of the cutting blades 12 having a protective cover 21 is 
splined to the lower end of the main shaft 19 for rotation therewith. 
The remaining pair of cutting blades 12 are coupled to the main shaft 19 by 
a belt 23 passed along a tension pulley 22. For this purpose a 
transmission pulley 24 made of metal plate is fixedly mounted on the main 
shaft 19 and positioned in the space between the box 16 and the frame 11. 
Similarly transmission pulleys 24 of metal plate are secured to the shafts 
25 of the other blades 12. The pulley 24 is made up of a dish-shaped base 
plate 24a and a V-grooved belt receiving member 24b integral therewith at 
an overlapping portion. 
The main shaft 19 fixedly carries a driven pinion 26 for receiving torque. 
A drive pinion 27 meshing with the pinion 26 is secured to the rear end of 
a pinion shaft 28 rotatably housed in the forward cyllnder 18, whereby the 
power from the front power take-off unit 9 is delivered vertically 
downward. The power from the unit 9 is delivered through a flexible 
universal joint 29 to the pinion shaft 28. The drive assembly for the 
cutting blades 12 consists essentially of the transmission box 16, main 
shaft 19 and pinion shaft 28 described above. 
The mower 10 is upwardly or downwardly movably supported by the tractor 
body 1 by means of a pair of lifting link mechanisms 30 disposed 
symmetrically on opposite sides of the body 1. Each of the link mechanisms 
30 comprises a fixed bracket 31, upper links 32, lower links 33 and a 
connecting rod 34. The fixed bracket 31 is detachably attached to the 
mounting bracket 8 and to the step 7 by a pair of front and rear brackets 
35. The upper links 32, as well as the lower links 33, are provided in 
pair, one positioned to the rear of the other. Each of the upper links 32 
has an upper end pivoted by a pin 36 to an inner portion of the fixed 
bracket 31 and a lower end fixed to the connecting rod 34 close to each of 
its front and rear ends. The lower links 33 have upper ends turnably 
fitting around the front and rear ends of the connecting rod 34 and lower 
ends pivoted to the mold frame 11 by pins 37. A lifting hydraulic cylinder 
38 is connected between the pair of connecting rods 34. 
A pir of front gauge wheels 39 are disposed to the front of opposite ends 
of the mower frame 11 respectively. Each of the front gauge wheels is of 
caster construction and is supported by the front end of each front 
pivotal arm 40. As also shown in FIG. 7, the front pivotal arm 40 is 
upwardly or downwardly turnably supported by a pin 42 on a bracket 41 
fixed to each of opposite end portions of the mower frame 11. The arm 40 
is provided at its base end with a coupling link 43 extending downward. 
To the rear of the center of the mower frame 11 is disposed a rear gauge 
wheel 44 which is supported by a pair of rear pivotal arms 46 secured to a 
coupling rod 45. These front and rear gauge wheels 39 and 44 are the gauge 
members 13. 
The coupling rod 45 extends transversely of the tractor body and is 
supported by brackets 47 at rear portions of the mower frame 11. Coupling 
links 48 extend upward from both ends of the rod 45 and are positioned to 
the rear of the coupling links 43 for the front pivotal arms 40. The links 
48 are operatively connected to the links 43 by connecting bars 49 
extending longitudinally of the tractor. 
Indicated at 50 is an operating lever, i.e. lifting or lowering operating 
member for adjusting the level of the cutting blades 12. The lever 50 is 
provided for one of the connecting bars 49 and forwardly or backwardly 
pivotably supported by a pivot 52 on a guide 51. As shown in FIGS. 5 to 7, 
the operating lever 50 has a bifurcated engaging member 53 in engagement 
with a pin 54 fixed to the connecting bar 49. The coupling links 43, 48, 
coupling rod 45, connecting bars 49, engaging member 53, pin 54, etc. 
provide a connecting assembly 55 for operatively connecting the front 
pivotal arms 40 and the rear pivotal arms 46 to the operating lever 50. 
Means 56 for locking the operating lever in its operated position comprises 
an engaging member integral with the guide 51 and having a plurality of 
indentations 58 communicating with a lever guide aperture 57 and arranged 
along the direction of turn of the operating lever 50, and an engaging 
pawl 59 secured to the lever 50 and engageable in one of the indentations 
58 by being forced therein with an unillustrated suitable elastic member. 
The lever 50 is operable by the operator sitting in the seat 6. 
The mower operates in the following manner. When lawn or the like is to be 
mowed, the operating lever 50 is moved forward or backward for the 
adjustment of the cutting height. When the lever 50 is moved backward 
about the pivot 52 rearward (in the direction of an arrow a) in FIG. 7, 
the connecting bar 49 is moved rearward as indicated by an arrow b by 
virtue of the engagement of the member 53 with the pin 54, pulling the 
coupling links 43 rearward and, at the same time, pushing the coupling 
links 48 rearward. This movement turns the front pivotal arms 40 downward 
as indicated by an arrow c about the pins 42 and also turns the rear 
pivotal arms 46 about the coupling rod 45 downward as indicated by an 
arrow d, with the result that the front gauge wheels 39 and the rear gauge 
wheel 44 move down relative to the mower frame 11 as indicated in phantom 
lines. Consequently the mower frame 11 is lifted, bringing the cutting 
blades 12 to a higher level to give an increased cutting height. After the 
front gauge wheels 39 and the rear gauge wheel 44 have been brought to the 
desired position by moving the operating lever 50 forward or backward, the 
pawl 59 on the lever 50 in the desired position is engaged in the opposed 
one of the indentations 59 in the guide plate 51, thus completely locking 
the lever 50 by the locking means 56, whereby the adjustment of the mower 
frame 11 as well as the cutting blades 12 is completed. In this way all 
the gauge wheels 39 and 44 can be easily adjusted as desired by the single 
operating lever 50, and the lever 50 is lockable also easily and reliably. 
Thus the cutting height is very advantageously variable, for example, 
during operation. 
For mowing, the hydraulic cylinder 38 is made free to stretch or collapse, 
and the mower 10 is lowered in its entirety with the front gauge wheels 39 
and the rear gauge wheel 44 brought into contact with the ground. The 
tractor is driven with the cutting blades 12 rotated in the direction of 
an arrow e by the power from the front power take-off unit 9. Since the 
lifting link mechanisms 30 are free to stretch or collapse, the mower 
moves up and down accurately along the ground level, enabling the cutting 
blades 12 to cut down grass, lawn or the like at a constant height. 
When the hydraulic cylinder 38 is contracted to lift the mower 10, both the 
link mechanisms 30 flexes by the same amount, raising the mower frame 11 
straightly upward. 
As the gauge members, sleigh-shaped members are usable in place of the 
gauge wheels. 
FIGS. 8 to 12 show another embodiment which is approximately similar to the 
foregoing embodiment in construction and operation. 
The tractor body 1 is provided at a rear portion with an upwardly or 
downwardly turnable lift arm 60 for raising or lowering a working 
implement, such as an unillustrated rotary tiller unit, attached to the 
tractor by three-point link means. The lifting link mechanisms 30 are 
vertically stretchable or collapsible with a wire 60 coupling the 
mechanisms 30 to the lift arm 60. 
The mower frame 11 is provided at opposite end front portions with 
upstanding front stays 62, with a first support rod 63 mounted on their 
upper ends transversely of the tractor. A second support rod 64 is 
attached to the stays 62 at intermediate portions thereof below the rod 
63. 
Each of the front gauge wheels 39 is of the caster type and has a vertical 
rod 65 turnably housed in a support tube 66, which has on its rear side a 
connecting plate 67 carrying upper and lower two movable pins 68, 68 for 
providing parallel links 69 positioned one above the other. The lower of 
the links 69 is an auxiliary link 40a, while the front end of the front 
pivotal arm 40 serves as the upper link 69. The rear end of the arm 40 is 
upwardly or downwardly movable by an operating lever 50 and a coupling 
link 70 for delivering the turn of the lever 50 to the arm 40 as an upward 
or downward movement. The arm end is lockable at a suitable level by a 
guide 51 having a series of wavy indentations 58. The opposed pair of 
front gauge wheels 39 are coupled by the elongated first support rod 63. 
The rear gauge wheel 44 is adjustingly movable upward or downward by the 
rear pivotal arm 46 and a coupling rod 71. Thus the level of the cutting 
blades 12 is adjustable. 
Since the front gauge wheels 39 are movable upward or downward by the 
parallel links 69, the vertical rod 65 of each front gauge wheel 39 can 
retain its axis in the same vertical position at all times. Thus even 
after the adjustment of the level of the mower frame 11, the front gauge 
wheels 39 are properly operable with stability, accurately following the 
travel of the tractor. Even when the front gauge wheel 39 idly turns about 
the vertical pin 65, the mower frame is retainable at the same level 
without shifting upward or downward because the vertical rod 65 remains in 
the same vertical position at all times. Thus the cutting blades 12 are 
held at the adjusted level to assure a uniform cutting height. 
As seen in FIG. 9, the tension pulley 22 is idly rotatable about a vertical 
pin and is biased by a spring 22a to tension the belt 23. Further as 
illustrated in FIGS. 9 and 11, wheels 11a, each rotatable on a horizontal 
shaft, are attached to the mower frame 11 at the midportion of its front 
edge and at opposite ends of its rear edge. These wheels 11a serve to hold 
the cutting blades out of contact with the ground and maintain a minimum 
spacing therebetween, independently of the adjustment of the gauge members 
13. FIG. 12 shows a modification of the locking means 56 of the first 
embodiment. The operating lever 50 is supported by a pin 50a on the 
coupling link 70 and is laterally turnable. The pawl 59 is held engaged in 
the indentation 58 by being biased by an elastic member, namely, a coiled 
spring 50b. This arrangement facilitates the engagement of the pawl 59 in 
the indentation 58. 
FIGS. 13 and 14 show another embodiment substantially resembling the first 
embodiment. As illustrated, this mower 10 is offset to the left side (or 
right side). The transmission box 16, mounted on and projecting upward 
from the mower frame 11, is disposed on one side of the tractor body 1 
outwardly thereof in corresponding relation to the clutch housing. This 
arrangement permits the mower 10 to be raised an increased distance to the 
full as illustrated in FIG. 12 since the box 16 is liftable without 
interfering with the body 1. Thus sufficiently large cutting height is 
available. With the mower 10 retained at a sufficiently high level, the 
tractor can be driven without any damage to the mower 10 that would 
otherwise strike some obstacle. With the transmission box 16 positioned 
outside the body 1, the transmission system can be checked for maintenance 
very easily and properly.