Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02240436 1998-07-07
RETRACTABLE PIVOTING SCRAPER BLADE FOR SNOW BLOWER
FIELD OF THE INVENTION
The present invention relates to a device for use with a snow blower having an
10 auger, to allow the snow blower to operate while moving backwards. The devicecomprises a blade that scrapes the snow and directs it towards the auger when the
snow blower moves backwards with the frame and auger lifted up to let the snow pass
underneath. Although the device has been designed to fit on a removable snow blower
of a tractor, it could be adapted to any type of snow blower having an auger.
BACKGROUND OF THE INVENTION
Two main types of snow blowers exist on the market, those being single-stage
and two-stage snow blowers. The single-stage snow blower is characterized by an auger
20 mounted transversely that conveys the snow to its center where a rotor that is integrated
onto said auger, projects the snow through a vertical duct. The mechanism of a single-
stage snow blower is illustrated in Figures 1 and 1a, identified as " EXISTING ART".
Arrows "A" indicate the movement of the snow that is conveyed by the auger and its
centrally integrated rotor; arrow "T" indicates the direction of motion of the snow blower;
25 and arrow "N" indicates the direction of the snow that enters into the snow blower. The
shortcoming of this type of snow blower is the high speed of rotation of the auger/rotor
combination that is required to eject the snow.
The two-stage snow blower incorporates a second stage that is added to a first
stage, which is identical to the one described for a single-stage snow blower.
30 The second stage adds a second direction of movement to the snow following the
movement initiated by the first stage. This second stage consists of an impellermechanism that propels the snow with force out of the snow blower. Figure 2, also
identified as " EXISTING ART", illuslldles the mechanism of a two-stage snow blower.
Arrow "A" indicates the initial displacement of the snow by the first stage, and arrow "B",
CA 02240436 1998-07-07
the displacement of the snow by the second stage. The second stage facilitates the
ejection of the snow and allows the use of an auger turning at a moderate speed.Advantageously, the optimum speed ratio of auger and impeller are easier to control.
However, both types of snow blowers described thus far have a common
shortcoming, and that is that they can only work while travelling in one direction i.e.
forwardly. In many circumstances, such as residential driveways and commercial
parking lots, operators must travel backwards repetitively in order to re-position the
equipment to blow snow in a forward movement. Each time the operator must back up,
the snow blower is unproductive. A snow blower rendered functional moving backwards
would increase its profitability by greatly reducing its idle time. Furthermore, as the snow
blower travels forward, it tends to push a certain amount of snow in front of it,
(represented by the letter "M" in Figure 2) which is left in front of any obstacle where the
snow blower must stop and back up. Hence, another type of equipment such as a plow
blade or a shovel must be used to remove the snow that has been left behind.
SUMMARY OF THE INVENTION
In order to maximize the productivity of a snow blower, a three-stage snow blower
has been developed within the scope of the present invention that will allow a snow
blower to blow the snow while moving backwards as well as remove accumulations of
snow close to obstacles. With a device according to the present invention, a two-stage
snow blower is transformed into a three-stage snow blower. More precisely, the three-
stage snow blower is a two-stage snow blower on which a retractable pivoting scraper
blade has been mounted. Therefore, the first and second stages of a two-stage snow
blower become respectively the second and third stages of a three-stage snow blower,
whereas the retractable pivoting scraper blade becomes the first stage which initiates
the movement of the snow through the machine. Originally, the retractable pivoting
scraper blade has been developed for use in combination with removable snow blowers
installed on trucks, tractors or the like. It is to be understood that with the appropriate
modifications, the retractable pivoting scraper blade can be adjusted onto other types
CA 02240436 1998-07-07
of snow blowers having an auger, such as walk- behind snow blowers, and large self-
propelled snow blowers that are integrated in a vehicle.
As the snow blower moves backwards, the retractable pivoting scraper blade
extends to the ground, the snow blower is lifted up to let snow pass beneath the snow
blower. Thus, the snow is scraped by the blade, and directs it toward the auger. In other
words, the blade feeds snow to the auger as the snow blower travels backwards.
An object of the present invention consists in a device for use with a snow blower
to allow the snow blower to operate while moving backwards. In accordance with the
invention, this object is achieved with a device for use with a snow blower,
said snow blower being of the type comprising:
- means for moving said snow blower forwards or backwards in a given
direction;
- a frame having a front opening, two side portions and an auger located
within the frame behind said front opening, said auger having an axis of rotation
transverse to the given direction in which said snow blower moves, and two opposite
ends, each of said opposite ends of the auger being rotatably fastened to a respective
one of said side portions of the snow blower frame,
- means for driving in rotation said auger;
- means for lifting up at least said frame and auger, and
- means for ejecting snow out of said frame and away from said snow
blower when said snow blower is in operation;
said device comprising:
- a blade having a concave surface, an upper part and two opposite ends,
said blade being pivotally mounted on said snow blower so as to pivot about an axis
parallel to the axis of rotation of the auger; and
- means for pivoting said blade between an operative position where the
blade extends close to ground and the concave surface of said blade extends in front
of said front opening in such a way that said blade scrapes the snow and directs it
towards said auger when said snow blower moves backwards with the frame and auger
CA 02240436 1998-07-07
lifted up to a predetermined height to let the snow pass, and an inoperative position
where the blade is raised to a height sufficient to let the snow reach the auger when the
snow blower moves forwards.
An inherent advantage of the invention is that it can be installed on existing snow
blowers with the aim of maximizing productivity by rendering them functional as they
travel backwards. Furthermore, the device is avantageously equipped with proximity
indicator rods to allow for the clearing away of snow close to any object such as a
garage door, wall or obstacle without risk of damaging it.
According to a preferred embodiment of the present invention, the device furthercomprises a flexible shield having an upper border and a lower border, where the upper
border is attached to support means located on top of the snow blower frame, and the
lower border is attached to the upper part of the blade along it. The flexible shield,
together with the blade in the operative position, cover the front opening of the snow
blower frame in such a way as to prevent the snow from being ejected over the blade
by the auger in rotation when the snow blower moves backwards.
When the snow blower is in operation and moves forward, the blade and flexible
shield are lifted out of the way of the auger and do not in any way hinder the work of the
snow blower.
A further object of the present invention is a a method for blowing snow with a
snow blower equipped with a device as defined above when said snow blower moves
backwards, the method comprising the steps of:
- lifting said snow blower to a predetermined height to let the snow pass
under it;
- pivoting the blade in the operative position;
- driving the auger in rotation; and
- moving said snow blower backwards.
CA 02240436 1998-07-07
The invention and its advantages will be better understood after reading the nonrestrictive description of a preferred embodiment of the present invention. Thisdescription is given with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figures 1 and 1a is a schematic representation of a single-stage snow blower
as is known in existing art.
Figure 2 is a schematic representation of a two-stage snow blower as is known
in existing art.
Figure 3 is a schematic representation of a three-stage snow blower when it
moves backwards, the snow blower being equipped with a device according to a
preferred embodiment, the blade of the device being in an operative position.
Figure 4 is a side view of a removable snow blower with a device according to a
preferred embodiment of the present invention, where the blade of the device is in
operative position.
Figure 5 is a similar view to Figure 4 where the blade is partially lifted up.
Figure 6 is a similar view to Figures 4 and 5, where the blade is in an inoperative
position.
Figure 7 is a front view of the frame of the snow blower illustrated in Figures 4 to
6, showing the auger and impeller mechanisms.
Figure 8 is a side view of the frame of the snow blower illustrated in Figures 4to6.
CA 02240436 1998-07-07
Figure 9 shows a removable snow blower including a device according to a
preferred embodiment of the present invention mounted on a tractor.
DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to Figures 4, 5, 6 and 9, a device (10) according to the present
invention is used with a snow blower (2) to allow said snow blower (2) to operate while
moving backwards. The device (10) has been designed especially for types of snow10 blowers (2) that work with an auger (4), as a removable snow blower (shown in Figures
4, 5 and 6) that can be mounted behind a tractor (shown in Figure 9) or on the front of
a truck as well as a walk-behind snow blower and a large self-propelled snow blower
integrated in a vehicle.
Throughout the following description, the forwards movement of the snow blower
(2) means that the snow blower (2) is moving in such a way that the snow (1) to be
blown is facing the auger (4) as the operation of a snow blower (2) is known andexecuted in existing art. Thus, the backwards movement of the snow blower (2)is the
movement during which the snow blower (2) cannot blow the snow (1 ) without the device
(10) of the present invention. It is to be understood that the forward and backward
movements of the snow blower (2) are defined independently of the direction of the
vehicle, tractor or truck combined with the snow blower (2); because the snow blower
(2) could be mounted on the back or on the front thereof, with an opposite orientation.
It should be understood that movement of the snow blower (2) and operation of the
snow blower (2) have different meanings since operation involves not only movement
but also rotation of the auger (4) and ejection of the snow (1).
Preferably, the snow blower (2)is of the type that comprises means for moving
the snow blower (2) forwards or backwards in a given direction. The means for moving
the snow blower (2) could be a motor included in a hand-propelled snow blower, atractor or a truck on which a removable snow blower is mounted, or a vehicle in which
CA 02240436 1998-07-07
a snow blower is incorporated. The snow blower (2) further comprises a frame (6)having a front opening (3), two side portions (7) and an auger (4) located within the
frame (6) behind said front opening (3).
As illustrated in Figures 7 and 8, the auger (4) has an axis of rotation "R"
transverse to the given direction (represented by the arrow "T" in the Figure 3) in which
the snow blower (2) moves, and two opposite ends (5). Each of the opposite ends (5)
of the auger (4) is rotatably fastened to a respective one of the side portions (7) of the
snow blower frame (6). The snow blower (2) also comprises means for driving in rotation
the auger (4); means for lifting up at least the frame (6) and auger (4); and means for
ejecting snow (1 ) out of the frame (6) and away from the snow blower (2) when the snow
blower (2) is in operation. The means for driving in rotation the auger (4) and the means
for ejecting snow (1 ) out of the frame (6) and away from the snow blower (2) are well
known in existing art.
Still referring to Figures 4, 5 and 6, the device (10) comprises a blade (12) having
a concave surface (14), an upper part (16) and two opposite ends (18). The blade (12)
is pivotally mounted on the snow blower (2) so as to pivot about an axis "P" parallel to
the axis of rotation "R" of the auger (4). The device (10) further comprises means for
pivoting the blade (12) between an operative position where the blade (12) extends
close to ground and the concave surface (14) of the blade (12) extends in front of the
front opening (3) in such a way that the blade (12) scrapes the snow (1) and directs it
towards the auger (4) when the snow blower (2) moves backwards with the frame (6)
and auger (4) lifted up to a predetermined height to let the snow (1) pass, and an
inoperative position where the blade (12) is raised to a height sufficient to let the snow
(1) reach the auger (4) when the snow blower (2) moves forwards. Avantageously, the
blade (12) is at least as wide as the auger in order to produce maximum efficiency. As
illustrated in Figures 3, the snow (1) which is represented by the arrow "N", passes
under the snow blower (2), is deflected by the blade (12) and redirected on the auger
(4).
CA 02240436 1998-07-07
According to the preferred embodiment, the blade (12) can be used as a support
and the means for pivoting the blade (12) as a lever in order to lift up the frame (6) and
auger (4). Thus, the means for pivoting the blade (12) are preferably sufficiently powerful
to raise the snow blower frame (6). It is to be understood that the means for lifting up at
5 least the frame (6) and auger (4) could also be any other mechanism devised for that
purpose. The height to which the snow blower frame (6) and auger (4) are lifted up is
preferably from 6 to 12 inches, depending on the model of the snow blower (2).
The means for pivoting the blade (12) preferably include a right assembly and a
10 left assembly which are similar and operate together. Each of the right and left
assemblies comprises a support (20) mounted on the snow blower frame (6). The
support (20) has one rear top corner pivotally connected to the snow blower frame (6)
about a first pivot (22) and a front bottom edge to which the corresponding end of the
blade (12) is attached. The means for pivoting the blade (12) preferably further include
15 power means for applying a rotational force '~' on the support (20) in order to pivot the
support (20) and the blade (12) connected to it around the first pivot (22). The operator
of the snow blower (2) has the possibility of raising the blade (12) to the desired height
above the snow (1) depending on its thickness, as can be observed by comparing
Figures 5 and 6.
The power means for applying a rotational force "\/' on the support (20) comprise
a powered cylinder (26) and an L-shaped lever. The powered cylinder (26) has a first
end (24) pivotally attached to the snow blower frame (6) and a second end (28). The L-
shaped lever has a first end (30) pivotally attached to the second end (28) of the
25 powered cylinder (26), an angular portion pivotally connected to the snow blower frame
(6) about a second pivot (32) and a second end (34). The power means for applying a
rotational force '~' on the support (20) further comprise a link (36) having one extremity
pivotally attached to the second end (34) of the L-shaped lever and another extremity
connected to support (20) about a third pivot (38) located at a given distance from the
30 first pivot (22) for transmitting the rotational force "~' to the support (20) and pivoting
said support (20). Therefore, the blade (12) pivots around the first pivot (22) when the
CA 02240436 1998-07-07
powered cylinder (26) is actuated thereby causing the L-shaped lever to pivot about the
second pivot (32). When the powered cylinder (26) retracts, the second end (34) of the
L-shaped lever is raised which pulls on the link (36) and then, pivots the support (20)
and the blade (12) around the first pivot (22) in direction "L" illustrated in Figure 4.
5 Avantageously, the powered cylinder (26) is a hydraulic cylinder. According to the
preferred embodiment, the first end (30) and second end (34) of the L-shaped lever are
two separate pieces that are tightly and solidly fixed together.
Avantageously, the axis ~pn about which the blade (12) pivots, is located behind10 the axis of rotation '.'R" of the auger (4).
Alternatively, the means for pivoting the blade (12) may include a blade frame
(not shown) which would be mounted on the snow blower frame (6), and the poweredcylinder (26) may be attached to that blade frame, instead of being attached directly to
15 the snow blower frame (6) as described above. Thus, according to the invention, the
powered cylinder (26) may be directly attached to the snow blower frame (6) or
indirectly, through a blade frame. Also according to the invention, the device (10) may
be designed as a removable apparatus, or integrated into a snow blower (2).
According to the preferred embodiment of the invention, the device (10) further
comprises a flexible shield (40) having an upper border (41) and a lower border (39).
The upper border (41) is attached to support means located on top of the snow blower
frame (6). The lower border (39) is attached to the upper part (16) of the blade (12)
along it. The flexible shield (40) together with the blade (12) in the operative position,
cover the front opening of the snow blower frame (6) in such a way as to prevent the
snow (1) from being ejected over the blade (12) by the auger (4) in rotation when the
snow blower (2) moves backwards. Avantageously, the flexible shield (40) is made of
rubber, reinforced with synthetic fabric such as Nylon~. However, the flexible shield (40)
can be made of any material that satisfies the need for preventing the snow (1) from
being ejected over the blade (12) and fall to the ground that has been cleared of snow
(1). It is an important characteristic of the shield (40) to be flexible when the blade (12)
CA 02240436 1998-07-07
is raised in the inoperative position because the shield (40) needs to be folded up as
shown in Figures 5 and 6.
The support means (43) located on top of the snow blower frame (6) includes a
S pair of spaced apart arms (42) to which the flexible shield (40) is attached. These arms
(42) are positioned to maintain the flexible shield (40) out of view of an operator
operating the snow blower (2) when the blade (12) is in the operative position or in the
inoperative position. Each of the spaced apart arms (42) extend forwardly in front of the
front opening (3) of the snow blower frame (6). Avantageously, each of the spaced apart
arms (42) is pivotally attached with a hinge (46) to the snow blower frame (6) and urged
down with a spring (48) connected to the frame (6) in such a manner as to keep it at a
lowest possible position for keepping the flexible shield (40) out of the operator's field
of vlew.
Preferably, the blade (12) has proximity indicator rods (44) fastened to each ofthe opposite ends (18) of the blade (12). The proximity indicator rods (44) extend
upwardly in the operator's field of view. These rods (44) help the operator lower the
blade (12) close to obstacles such as garage doors, walls or the like, without damaging
it.
As can be appreciated, a snow blower (2) equipped with a device (10) according
to the invention, may operate while moving backwards and therefore, maximize theproductivity of the snow blower (2). The device (10) also has the benefit of allowing the
snow blower (2) to blow a certain amount of snow (1) that would be left in front of any
obstacles. A method for blowing snow (1) with a snow blower (2) equipped with the
device (10) according to the invention, when the snow blower (2) moves backwards,
comprises the steps of (i) lifting said snow blower (2) to a predetermined height to let the
snow (1) pass under it; (ii) pivoting the blade (12) in the operative position; (iii) driving
the auger (4) in rotation; and (iv) moving said snow blower (2) backwards.
Although a preferred embodiment of the invention has been described herein and
illustrated in the accompanying drawings, it is to be understood that the invention is not
CA 02240436 1998-07-07
limited to this precise embodiment and that various changes and modifications may be
effected therein without departing from the scope or spirit of the invention as defined in
the appended claims.
