Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
PN ~fl~ No. ~sLo24/JTN 2 1 66 4~ ~
Titles ONB ~A~ PLO~ BLADE
Thi~ ihvent~on relates generally to the fleld of
heavy mechanlcal road ~orking equlpment and, ln
S particular, relate8 to bl~des of the typ~ that ~ay be used
by such road wor~ing equipment to work ~urfaces such as
gravel or hard top road~, shoulders and runways. Such
blades may be used for example for the purpose of snow
removal fro~ hard top or gravel road~, or for the purpo~e
of qrading gravel or earth road~ and ~houlders.
BAC~GROYND O~ THB I m NTIO~
~ ea~y machinery and equipment i~ u~ed for th~
pu~pose of ~orking road and other transportation surface~.
Such heavy equipment ~nclude~ graders, truck~, and other
machine~ ~hich are sufficlently robust and po~erful to
pu~h dirt and sno~ for the purpo~e of forming good clear
travel ~ay~ for ~ehicular traffic. Such machine~ suitable
for road Yorking typically include a mould board, ~hich is
simply a mechanical linkage onto which variou~ types of
blade~ may be attached. ~he mould board i8 typ$cally
ad~ustable ln helght, and in angle, to allo~ for different
type~ of plo~ing or blading actlon. The t~o main u~e~ of
~uch blades are for the purpose of grading d~rt road and
shoulder~, and for the purpose of clearlng ~no~ from hard
25` top ro~dvay~, run~ay~, parking lots and the like.
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Such blades are typically made fairly thin, in
order to reduce the materials C08t in producinq ths b}ads.
Additionally, a thin blade ~8 much easier to work, ln the
manufacturing stage, such as by bending, machining
S attachment holes, and milling grooves for attachment of
wear resistant inserts. Of course the blades mu~t still
be substantial enough to be reasonably durable in their
intended use.
Problems can occur however by reason of such
thin blades. For example, a thin blade may tend to dig
into a surface which i~ not hard. An example of this i~
a blade which digs into a soft earth surface deeper than
is intended and rather than smoothing the surface ends up
digging or gouging the surface. This is a particular
problem in vehicles having large rubber tires and
su~pension systems which mean that the operator, although
trying to control the depth of penetration of the blade
cannot with the range of movement of the flex of the tires
and the suspension. This effect is exacerbated at even
moderate speeds where there is a tendency for the vehicle
to bounce around as it encounters unevenness in the
roadway. While an up bounce i~ not too seriou~, because
of the tendency of the blade to return to its proper
position, a down bounce is more problematic. As the blade
is bounced down, it ~ill tend to dig into the ground,
which will increase the weight on the blads and tend to
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force the blade even deeper. The~deeper the blad~ goes,
the greater the force digging it into the ground. Flnally
the re~iliency of the ~uspension of the vehicle and the
tire~ will overcome the down forces and bounce the blade
S up. Because of the size of the forces reguired the up
movement can be so much as to cause the blade to come free
of the ground, result~ng in an undulating rather than A
smooth surface after the vehicle has passed. This is
especially a problem in colder climates where the ground
may be formed in a frozen but relatively thin crust.
Further, a relatively thin blade, while
desirable in being relatively light weight for
manufacturing and shipping purposes, i8 al~o not as
strong. Thus, if while in use the blade encounter~ a
boulder or other substantial ob~ect there is a risk that
the blade will be damaged by being non-elastically
deformed and that such damage will even be transmitted
through the blade to the mould board. If the mould board
is damaged, by also being non-elastically deformed, it may
no longer fit blade replacements. Since the mould board
is an integral part of the road working vehicle, fixing
damage to the mould board requires taking the vehicle out
of service completely rather than being able to replace
the worn or damaged road working blade.
25In the past there have al80 been problems ~ith
- ~ing blades. ~ing blades are blade e~tensions that are
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connected to the main blade at ono side edgQ. They e~tend
out from the vehicle like the ~ings of a bird, hence ~ing
blades. They typically would be at a quite different
angle of attack from the main blades, one that ls more
S likely to be e~posed to glancing impact~ with obstacles in
the ~urface to be worked. HoYever since they are not
connected at the back to the ~old board, like the main
blade i8, there are no attachment holes along the wing
blade body. Thus there are no restrictions on the ability
to adapt the ~ing blade by for example making attachment~
to the rear face of the wing blade to overcome the
problems noted above for thin blades. Therefore, there
have been in the past, ~ear blocks attached to the rear
face of such wing blades. Such ~ear blocks have been for
the purpose of estending the wear surface of the wing
blade and typically have been formed with an angle of
about 70 degrees to the wing blade.
BRIE~F SIJ~ARY OF THI~ INVEN~ION
What is desired therefore is a road working
blade, for use on road working equipment and vehicles,
which is able to resist transmitting damage to a mould
board, and yet which provides a good ability to work
surfaces in a controlled manner. Preferably such a
re~laceable blade would be easy to use, by not tending to
over cut in difficult condition~, namely, where there are
a combination of soft and hard substances being worked, or
where the ground being worked i~ partially frozen.
216S~2~
Further, such ~ blade would overcome the problems
associated with ~ much different ~n~le of attack th~n a
wing blade, the presence of attachment openlngs along the
main blade and greater stresses the main blade is
~ub~ected to as compared to ths wing blades.
Therefore, there i8 provided according to the
present invention, a replaceable blade for working a
surface, said blade being of the type that i8 mountable
onto a mouldboard of a roadworking vehicle, said blade
comprising:
a blade body having a length, a height, and a
thic~ness, and upper and lower edges, wherein said length
i5 greater than said height and said height is greater
~han said thickness, said blade body including means for
attaching the blade to a mould board of a vehicle and
at least one shaped stabilizing means, connected
to a rear face of said blade body, said shaped stabilizing
means having a mass sufficient to increase said blade
body's flexural strength, said shaped stabilizing means
including a bottom face cooperating with said lower edge
of said blade, wherein when said blade is installed on a
mould board at a predetermined angle of attack relative to
a surface to be worked, said bottom face is generally
parallel to the surface to be worked to inhibit the blade
from being driven lower relative~~to said surface than is
desired.
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DETAILED DESCRIPTION OF THE FIGURES
Reference will now be made to the following
figures which illustrate by way of reference only
preferred embodiments of the invention and in whichs
S Fig. 1 shows a rear view of a preferred embodiment of the
replaceable blade according to the preferred embodiment;
Fig. 2 shows a section through line~ 2-2 of the
replaceable blade of figure l;
Fig. 3 shows a ~ide view of a component of the
replaceable blades of Figs. 1 and 2;
Fig. 4 is a isometric view of the component of
Fig. 3;
Fig. 5 is a further side view vf the component
of Fig. 3;
Fig. 6 is a front view of the component of Fig.
3;
Fig. 7 is a top view of the component of Fig. 3;
and
Fig. 8 is an isometric view of a nose piece for
a replaceable blade as shown in Fig. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figure 1, a replaceable blade
according to the present invention i~ shown generally at
10. The b~ade 10 i~ comprised of a blade body 12, which
6~
has 2 length 14, a height 16, and a thicknes~, shown a~ 18
in Fig. 2. Returning to Flg. 1, the blade body 12 ~180
has an upper edge 20 and a lower edge 22.
In the preferred embodiment the length l~ i~
S greater than the height 16, which in turn is greater than
the thickness 18. Good results have been achieved where
the length is about 132 inches, the height i-~ about 8
inches and the thickness is about 5/8 ths of an inch.
However it will be appreciated by those skilled in the art
that while these dimenslons are preferred, other
dimensions may also be used with satisfactory resulta.
What is re~uired is to provide a blade body with overall
dimension~ which make it compatible with the mould board
of a road working vehicle so that the blade body will be
mountable thereon. Different vehicles may have slightly
different standards which need to be accommodated by
varying the preferred dimensions noted above.
The blade body 12 is also provided with means
for attaching the blade body to the mould board of a
vehicle, which in the preferred embodiment take the form
of a row of mounting apertures 24. The most preferred
embodiment is to provide 11/16 ths inch rectangular holes,
which are countersunk with a 1 1/8 ths inch diameter drill
bit, to form a rounded opening on one side of the blade.
As shown in Fig. 2, there is a front of the blade body 26
having a rounded opening 28, and a rear of tha blade body
2~ g~fi
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~ 30, hav~n~ a squared opening 32. Pre~erably the mountinq
aperture~ are spaced on 8 inch centre~ (shown as distance
25), with the outermost one being 2 inches from the end of
- the blade 10 (shown as 27).
Also shown in Fig. 1 i8 a shaped stabilizing
means 34 which in the preferred form comprises a bloc~ or-~
metallurgical casting as described in more detail below.
Also shown are an angle member 36 and side gusset plates
38, 40. As can be seen in Fig. 2, the block 34 ha~ a
thickness 42, and a front height 44 and a rear height 46.
The preferred thickness is about 1 3/4 th~ inches, the
preferred front height is about 3 3/4 inches and the
preferred rear height is about 2 inches. Again it will be
appreciated by those skilled in the art that these
dimensions can be varied provided the block 34 still
functions as described below and al50 fits within the
constraints of a conventional mould board.
As can be seen in Figs. 1, 2, and 3, the block
34 includes a bottom face 48, which extends between the
front hei~ht 44 and the rear height 46, and forms an angle
A relative to the plane of the blade body 12, which i5
shown as 50. It will also be noted that in Flg. 1 the
bottom of the block is closely ad~acent to a bottom edge-
52 of the blade body 12. Thus the blade bottom 52 and the
bottom face 48 of the block 34 cooperate to form a plane
which i~ relatively long relative to the thickness of the
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blade body ~2. It w~ll be appreclated by those skllled
art that the angle A must be any su~table angle, provided
that it i8 generally within the range of ad~ustment of the
mould board of the veh~cle. The preferred angle 18
between 130 degrees and ~0 degrees with the ~ost
preferred being about 135 degrees. Looking at this angle
from the other side, the preferred angle , relative to the
height of the blade i8 between about 40 and 50 degr~es,
with the most preferred angle being a~out 45 degrees.
Fig. 4 shows the block 34 in perspective view,
with the front height 44, the th~ckness 42, and ths bottom
face 48. Also shown are the sides 60, 62 which are form~d
at an inward angle towards the bottom of the block. This
can be more clearly seen in Pig. 1, and is explained mo~e
fully below.
The preferred materiAl for the block 34 is a
metallurgical material which ha~ a hi~h strength, abrading
durability, and preferably i8 not too expensive.
Satisfactory results have been achieved with a composition
comprised of 2.90 to 3.6 units carbon, 0.4 to 0.6 units
silicon, 0.4 to 0.7 units manganese, 4.00 to 4.75 unit-Q
nickel, and 1.4 to 3.5 units chrome. The preferred
hardness is in the range of 500 to 600 on the Brinell
scale. This metallurgical composition ha been found to
provide the reguisite mass and strength to sub~tantially
protect the mould board from being damaged during blading.
2 ~
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In comb~natlon wlth the shape of the block 34 the material
al~o tends to stabilize the blade, to pre~ent the cycle of
unwanted over-cutting described in the bac~ground sect~on
above. A~ will be apprec~ated however th~ metallurgical
composition is not easily worked.
The preferred method of forming the block 34 i~
by casting. For ease of manufacture and for strength, it
is preferred to make the block 34 as a solid integral
unit. This presents a problem howe~er, in that the
material i8 too hard to be reliably or easily welded.
Therefore the blocks 3~ must be attached to the blade 10
by some other means.
Returning to ~igure l, it can be seen that the
each block 48 is in essence retained in an open bottom
pocket formed by the a co~bination of the angle 36 and the
gusset plates 38, 40 which interact with the side edges
60, 62. The angle 36 is preferable forméd as a right
angle and is a single continuous piece runninq from one
side of the blade 10 to the other side. It is preferably
welded along the intersection with the blade which is
shown as 64 in Figure 2. Six inch welds every si% inches
ha~e been found satisfactory for this purpose. Once the
angle 36 has been welded on, the blocks can be positioned
and then the gusset plate~ can be welded in place. It
w~ll be appreciated that since the gusset plates cannot be
welded to the block 34 , they are welded along their
~6~2~
perlmeter to flrst the blade 10, th~ outward leg 66 of the
anqle 36 and the to the overhanging leg 68 of the angle
36. In th~s manner a strong yet open bottom pocket is
formed to carry the block 34, without needing to ~eld the
block 34 to the blade directly.
Returning to Figure 2, it can now be appreciated
how the present invention i8 configured to allow it to be
positioned onto a conventional mould board of a vehicle.
The angle 36 is attached at a distance d below the upper
edge of the blade 10. The distance d must be enough to
accommodate a conventional mould boards and it has been
found that 3 1/2 inches is satisfactory. There is also
shown a distance e which is the length of the overhanging
leg 68 and which is preferably 2 inches. As can be seen
there is preferably a gap shown as f which exists between
the end of the outer leg 68 and the block 34 and which i8
preferably 1/4 inch. Thi~ shelters the edge of the angle
behind the corner of the block, when the blade is in use
and thus prevents the angle from ~etting cauqht on some
obstruction and being damaged. There is also shown a
distance g which is preferably 1 3/4 inches and a distance
h which i~ 1/2 inche~. The distance h is simply to let
the blade 10 wear to a compatible surface to the bottom
~ face of the block 48 to maximiz~ the seating or running
~urface which is formed by the bottom face 4B.
Figures 6 and 7 sho~ the block 34 in plan and
~ ~ 64~G
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bottom view~ and illu~trate more clearly the ~h~pe of the
block 34. The distance shown as 70 i8 preferably about 8
lS/16 inches and the distance 72 i8 preferably a~out 1 3/8
inches. The distance 74 in figure 7 i8 preferably about
S l 3/4 inches and the preferred vslue of angle 71 is 78
degrees, although this could be varied somewhat.
Essentially what is required i8 that the angle bo
sufficient to safely retain the bloc~ 34 in the open
bottom pocket formed between the angle piece 36 and the
gusset plates 38,40.
Turning to Fig. 8, it has also been found that
a shaped stabilizing ~loc~ 80 may be usefully added to a
nose piece , which is a device used in connection with the
blade 10. A nose piece 82 is shown in Fig. 8 which
includes a round footed leading flange 84 and an
attachment flange 86. The part~ 84,86 are preferably
welded together, in such a way as to form an angle
therebewteen of about 105 degrees. Other angles may also
be used but this one provides adequate result~.
The nose piece has an attachment opening 88
which is identical to the mounting apertures 24. This
makes the nose piece compatible with the blade 10 and the
mould board of conventional vehicle~. The block 80 is~
generally similar to the block 34 in terms of
metallurgic~l specification~, but l~ smaller to
accommodate the smaller ~pace on the rear of the
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attschment-flanqe of the nose piece. For example rather
than being 8 15/16 inches long the block 80 i8 3 7/8 ths
$nches long.
It can now be appreciated hov the inst~nt
S invention i8 an improvement over the conventional blades.
~nlike the 70 degree angle for the wing blades, the
instant invention is poæitioned to an angle of about 45
degrees. Thiæ has the effect of greatly increasing the
~ear ~urface of the wear re~istant block. In this manner,
the stability, life and durability of the blade are
increased. Additionally, the preferred form of the
invention i8 to uæe continuous welding of the angle to the
blade, to ensure a strong and ea~y to make ~oint between
the two. Additionally, the blocks are dimensioned to be
retained on the back of the blade ~ithout interfering with
the attachment holes, which are required to secure the
blade to the mould board of the vehicle. Additionally,
the blade i8 combined with nose pieces ~hich are adapted
to be ~ear resi~tant ~hich also increase the utility of
the invention.
rt will be appreciated by those skilled in the
art that the foregoing description is by way of example
only and that there are ~arious modifications and
alteration~ to the form of the invention that can be made
without departing from the brosd scope of the invention a~
defined in the following claims. Some of these variations
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have been discussed above and others wil-l be apparent to
those ~killed in the art. For example, although the
preferred dimenslons have been provide, varlations from
these dimension~ would not affect the invention as long as
the variations were such that the blade 10 was still
compatible with conventional mould boards.
