Note: Descriptions are shown in the official language in which they were submitted.
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ULLDOZER BLADE MOUNTING hPPA~ATUS
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. I - BAC~G~OUND OF:THE INVENTION
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. ¦ This invention relates to.a bulldozer blade mounting . :~-
apparatus for use in earth moving vehicles.
I It is generally ~nown to turn the blade mounted on
.. I an earth ~oving vehicle about the vertlcal axis of a pivot .. :,
. . ¦ shaft of the mounting fra~e thereof.thereby angling the lef~
jl and right ends of the blade in the longitudinal direction o
!I the venicle or turn the blade about the horizontal axis of the -~
,~ pivot shaft of the mounting frame thereby tilting the left and .
- right hand ends of the blade in the vertical direction. An
. apparatus for controllin~ the posture or displacement of such
. blade is disclosed in U.S. Patent No. 3,631,930.
The apparatus disclosed in the above-mentioned paten~
; comprises a-blade connected at three points with a ~nounting
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frame by ~eans of universal spherical ioints and first and
. second double-acting hydraulic jacks mounted on the left and
righ~ sides of the v-ehicle~ and a third double-actlng hydraulic
ii jack for holding the blade in.a stable condition, the arrange- ¦
20 il ~ent beincr made such that the angl;ng OL the blade can be
controlled ~y extending or retracting said left and rigllt hand ¦
double-acting hydraulic jac~s in the opposite direction, ~hilst
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!'. thc tilting of the blade can be controlled by extendin~ or
1 retracting said third double-acting hydraulic jack.
¦ In the case of such appara~us~ the posture of ~he
¦~ blade can be de~ermined only by the ad~ustment of the length
Il of the hydraulic cylinder so that if the llydraulic fluld
- ! leaks from the left and rigllt hand double-act;ng ihydrauiic
jacks and hydraulic pressure control valves thereor, the
¦ longitudinal posture of the blade cannot be held and *he blade
will turn its face downwards whilst the load imposed on the
~ blade in the earth moving operation tends to turn the face of
I the blade upward t]lus causing harmEul wear-down and abnorr,lal
Il stresses in the connecting portion of the blade and the mount-
!i ing frame, and also reducing the efIiciency of the exca~ating
. blade of thrusting into the earth and sand as ~ell as the earth ;
and sand rolling up and moving efficiency thereof.
Furthe~, in SUCII apparatus, i~ and wllen the control ! `
circuit for the left and right hand double-acting hydraulic ~ ~-
jac};s is out o order and tlle effect of tne hydraulic fluid
~, for l;eeplng the position of tne extensible and retractable
1 rod becomes unavailable, the desired posture of the blade
¦' cannot be maintained relative to the r.lountin frame thereof;
¦i in otner words, the posture or position of the blade will be
out of control thereby damaging the connecting portion.
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SUMMARY OF T~ INVENTION
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It is therefore an aspect of the present invention
to provide an improved mounting apparatus for supporting a
bulldozer blade on a vehicle.
Another aspect of the present invention is to
provide a bulldozer blade mounting apparatus wherein the
blade can be supported securely and the posture of the
blade cannot be changed even if one of the hydraulic jacks
for angling the blade becomes out of order.
In accordance with an aspect of the present invention,
there is provided a mounting apparatus for supporting a bulldoæer
blade on a vehicle comprising a mounting frame having side
members, each with one end pivotally connected to said
vehicle and extending therefrom, and an intermediate
member interconnecting the other ends of each of said side
members;
a universal joint for connecting a central
portion of said blade to said intermediate member;
a pair of hydraulic jacks for angling said blade,
each one of said jacks having one end pivotally connected
to said mounting frame and the other end connectible to
the side of said blade;
means for operating said pair of hydraulic jacks
in opposition to each other for adjusting the angle of ;~
said blade; ~:
first bracket means fix~dly secured to the
intermediate member of said mounting frame;
second bracket means fixedly secured to said
bulldozer blade; :
a tilting jack pivotally connected to and extend-
ing between said first bracket means and the back side ^
of said blade;
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a supporting rod pivotally interconnecting said
first and second bracket means wherein the connecting portion
of said second bracket means and said supporting rod being
positioned adjacent to a vertical line passing through the
center of said universal joint; and
first and second ball joint means at opposite
ends of said supporting rod for pivotally intexconnecting
said supporting rod with said first and second bracket means,
said hydraulic jacks being of double-acting type
and rod-side chambers being connected with each other thereby
maintaining the sum of the entire length of said pair of
hydraulic jacks, including piston rods, constant.
The above and other aspects, features and advan-
tages of the present invention will be readily apparent
from the following description taken in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a blade mounting
apparatus according to the present invention;
Fig. 2 is a schematic perspective view showing
the operation of the blade mounting apparatus of the present
invention;
Fig. 3 is a schematic plan view of a blade mounting
apparatus when the apparatus is in tilting operation;
Fig. 4 is a schematic view o~ a blade when the mount-
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. ing appa~atus is in tilting operation;
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', Fig. 5 is a schematic plan view of a ~lade mounting
apparatus when the apparatus is in analing operation;
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tj ~ig. 6 is similar to Fig. 4 but sho~ing the mounting
apparatus being in angling operation; and
¦~ Fig. 7 is a hydraulic circuit for a blade mounting
!l apparatus of the present invention. . :
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ll DETAILED ~ESCRIPTION O~ THE INVE~TION
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ii . The present in~ention will now be described in detail
. below by way of example only with reference to the accompanying
~, drawings. ln the drawings, reference nu~eral 1 denotes a mount- I
;- ing frame comprising left and right hand side members 2 which I -
are mounted on a vehicle body not shown through their pivots 3a.
Fi~edly secured to the side members 2 of the mounting frame 1
are bracXets 3 to which double-acting hydraulic jacks 4 are
,I connected. The operation of the double-actinn hydraulic jacks 4
.; can rise.~and fall the mounting frame 1
Reference numeral 5 indicates a blade ~-Thich is con-
, nected tc the mounting frame 1 by means of a unlversal ball
'. joint 6. Brackets 7 and 8 are fixedly secured to the rear
'. face of the blade 5 on the left and right sides thereof. Further,
¦ double-acting hydraulic jacks 11 and 1~ are attached to the
base ends of the above-mentioned bra~ckets 3 Dy means of ~all .
joints 9 and 10. The hydraulic jacks 11 and 12 have respective
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ro~s 13 and 14 lY]liCh are connected to tne brac~ets 7 and 8 by
-i means of ball joints 15 and 16, respectively.
j, Fixedly secured to the central part of a cross
¦ member of the moun~ing frame 1 i5 a base bracke~ 17. Fixedly
¦ secured to the front part and the upper part of the base
bracket are brackets 18 and 19. A hydraulic jack.20 for tilting ~1
¦¦ the blade 5 is connected at its base end by a ball joint 21
to the brac~et 18~ the hydraulic jack 20 includes a rod 22
which is connected by a ball joint 24 to a brac~et 23 fixedly
¦ secured to the rear face of the blade 5. A bracket 25 is
, rigidly secured to the central; upper part of the blade 5.
¦I One end of a supporting rod 26 is connected to the bracket 25
by means of a ball joint 27. The other end of the supporting
j rod 26 is connected to the bracket 19 by means of a ball joint .
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j The zonnection o the supporting rod 26 is made in :~;
i such a manner as to select an technically optimum position there-
i~ of in the displacement of the blade in the direction of angllng I ,
., and tilting. This will no~ be described belol~ with reference , :.
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20 . to Figures 2 to 6. ¦
,~ By connecting the blade S to the mounting frame 1 by
1, means of the universal spherical ioint 6 and the hydraulic .
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: ~j jac~s 11 and 12, the blade can be moved in a ~e~-p~*~æ
¦! relative to the mounting frame 1.
I If an optional point Al is ta~en on the surace o~ the
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, bl~de S, the point A' can move along only one curve as the blade
5 is ~oved.
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i, ~ Next, if the lengths of the hydraulic jacks 11 and 12
j are set at Cl and C2, respectively~ and the lengths are changed
¦~ from Cl and C2 to Cl' and C2' so as to keep the sum of the
. ¦ lengths of the hydIaulic jacks 11 and 12 or Cl ~ C2 constant,
then the point A' ~ill move along only one curve in the similar
manner.
.. ~ Then, i the.point A' is located at a point A near
the vertical line passing througll the oscillation centre.B of .
the blade 5, the amount of movement of the point A at the time .
of angling i5 small relative to the support frame 1. Even if
the lengths of the hydraulic jacks 11 and 12 are changed Erom
Cl and ~2 to Cl' and C2', respectively, the point A will move I .:
: along the same curve relative to the support frame 1 as shown
i~ Figures 5 and 6. ACCOTding1Y, even if a spontaneous point
on the support frame 1 is directly connected to the point A
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near the vertical line passing through the oscillation centre ! ~
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B of the blade 5 by the supporting rod 26, no excessive stress
is created on the supporting rod 26. Also, the supporting rod
, 26 is not forcibly twisted in the direction of tilting.
,. - In order to achieve smooth and satisfactory operation
- ~; without causing excessive stresses in every component par~ at ¦ I
¦~ the time of angling and tilting of the blade 5 by attaching the ¦
,.supporting rod.26 between the blade 5 and the support frame 1,
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i,.is essential to ~perate the hydraulic jacks ll and 12 sr,loothly
so as to balance their lengths. Such operation is made by a
hy~Iaulic control circuit shown in Figure 7.
" ; In ~igure 7, the fluid under pressure delivered by a
- ¦¦ hydraulic pump 40 can be selectively supplied by a blade angling
¦I control valve 41 into either a circuit 42 or a circuit 43. The
. ¦ circuit 42 is connected to the bottom side of-the cylinder of
... ~ the hydraulic jack ll, whilest the circuit 43 is connected to
I the bottom side of the hydraulic jack 12. The head sides of the
l¦ cylinders of the hydraulic jacks 11 and 12 are interconnected by
j a circuit 44 so as to communicate.with each other thereby
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eliminating return path to the hydraulic fluid reservoir and . ;.
.sealing the non-compressible fluid to enable the pressurized
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1 fluid to communicate with both cylinders of hydraulic jacks 11 :-~
and 12. Therefore, when the pressurized fluid selectively sup-
plied through either the circuit 42 or the CiTCUit 43 is fed
. into one of the hydraulic jac~s so as to extend the rod thereby,
the fluid sealed in the head side thereof is fed into the head
- side of the other hydraulic jack 50 as to retract the rod of the
latter and achieve angling of the blade 5. Therefore, the sum
.,of the lengths of the left and right hand hydraulic jacks ll and
~12 can be.kept ConStBnt.
As mentioned hereinabove, the present invention com-
~prises a suppoTt frame 1~ a blade 5 mounted on the support frame
.l so that it can be pivotted longitudinally and horizontally~
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brackets 3,3 fixedly secured to the side members 2,2 of the
support frame 1, said brackets 3,3 and the blade 5 being
' connected by hydraulic jacks 11 and 12, a bracket 25 mounted
!' near the vertical line passing through the oscillation centre
: I B of said blade 5, a bracket 19 mounted on the support frame 1
¦ opposite to said brac~et 25, said bracke~s l9 and 25 being
pivotally connected by a supporting rod 26, and a tilting
¦ hydraulic jacks 20 connected between the blade 5 and the suppor~
I frame 1 or controlling the tilting of the blade 5.
10 I Therefore, the blade 5 can be held securely by the
support frame 1 and no excessive stress is created in every
component part when the blade 5 is moved.
! Further, the longitudinal posture of the blade 5remains unchanged even if a trouble occurs in the left and
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right nand hydraulic jacks 11 and 12, and therefore the apparatus,
will not run into dangerous condition.
Further, the apparatus itself can absorb the displace- !:
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nlent three-dimensionally which is caused by *he operation and ;
also ~he structure can be subs~antially simplified as compared l ,;
! with ~he conventional supporting apparatus which can absorb
the displacement of the blade two-dimensionally. Iioreover,
,I the posture of the blade 5 in the longitudinal direction is ¦~
¦ maintained at four points, and so the rigidity of the appara-
i~ tus can be ~uch improYed.
hile the invention has bëen described and shown with
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I, particular reference to the preferred embodiment, it will be
¦, apparent that ~ariations might be possible that would fall
within the scope o~ the present invention, whlcll is not
. j, intended to be limited except as deflned in the o11o~ing
: claims.
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