Note: Descriptions are shown in the official language in which they were submitted.
CA 02476663 2004-08-04
PORTABLE MIXING APPARATUS
BACKGROUND OF THE INVENTION
a. Field of the Invention
The present invention relates generally to an apparatus for mixing mortar,
cement,
and similar materials, and, more particularly, to a portable mixer for
preparing such
materials in ordinary disposable plastic buckets.
b. Related Art
Certain materials and compositions require mixing prior to use, particular
examples
of such materials being grout, mortar, plaster and cement. For example,
masonry work or
tile work typically requires that the mortar or grout be mixed at the jobsite
immediately
before use.
Unlike concrete, which is typically obtained in large volumes from a ready-mix
plant or a mixer truck, mortar and grout work employ fairly small batches of
material. For
example, a brick mason or tile setter will typically prepare a small batch or
mortar or grout
for work at a first job site and then move to another job site and prepare
another batch of
material, as, for example, when moving from one house to another in a
subdivision that is
under construction.
Consequently, both portability and the ability to prepare small batches of
material
quickly and efficiently are important factors. Cost is also a significant
important factor,
particularly since many or most brick masons and tile setters are independent
professionals
who must buy all of their own equipment.
Currently available mixers do not adequately satisfy the foregoing criteria.
Mortar
or grout can, of course, be mixed the "old fashioned" way simply using a
bucket and
trowel, however this is neither convenient nor efficient, except for very
small amounts of
material. On the other hand, existing motor-driven mixers are expensive and
lack adequate
portability. For example, conventional mixers typically employ comparatively
large steel
CA 02476663 2004-08-04
2
or plastic drums that are rotated by an attached drive. Not only are the
mixers themselves
bulky and difficult to transport they are also cumbersome to use, since the
drum must be
dumped out into a smaller, second container (such as a bucket or tray) from
which the
mortar/grout is then applied. Moreover, the entire drum must be rinsed out and
cleaned
between jobs, lest it become encrusted with hardened material.
l0 Another category of mortar/grout mixing devices employ rotating blades that
are
mounted on the end of a long shaft and driven by an electric motor, somewhat
resembling
an outsized paint mixer driven by an electric drill. These are inserted into
tubs so as to
generate a stirnng action that mixes the components. In practice, however,
this class of
devices is highly unsatisfactory for several reasons, including inadequate
mixing of the
materials and the messy, cumbersome and physically tiring action that is
inherent in their
operation; moreover, the fact that they are manually operated means that other
work must
be stopped while the mortar/grout is being mixed. Another existing device
resembles a
small "roto-tiller" that mixes the material in a plastic trough, which
combines the
drawbacks of the "electric drill" type mixers with the cost, portability and
cleaning
problems associated with drum mixers.
Accordingly, there exists a need for an apparatus for mixing mortar, grout,
and
similar materials that is portable and readily transportable for going from
one job site to the
next. Furthermore, there is a need for such an apparatus that is convenient
and easy to
operate, yet which provides thorough mixing of the material. Still further,
there is a need
for such an apparatus that does not require the mortar, grout or other mixed
material to be
pumped into a separate container for use. Still further, there exists a need
for such an
apparatus that is inexpensive, requires minimal maintenance, and is long
lasting in use.
CA 02476663 2004-08-04
3
SUMMARY OF THE INVENTION
The present invention has solved the problems cited above, and is a compact,
easily
transportable mixing apparatus that employs disposable 5-gallon plastic
buckets as the
containers for mixing mortar, grout, plaster and other materials.
Broadly, the apparatus comprises: (a) a drive assembly having (i) first and
second
generally parallel drive rollers that are spaced apart so as to form a cradle
area for receiving
the side of a plastic bucket therein, and (ii) means for rotating at least one
of the drive
rollers so as to rotate the plastic bucket when the bucket is in engagement
therewith, and
(b) a mixing basket for being placed within the interior of the plastic
bucket, the mixing
basket being free from attachment to the bucket and having at least one mixing
blade for
agitating the material in the bucket as the bucket is rotated by the drive
rollers.
The drive assembly may comprise means for rotating both the first and second
drive
rollers. The means for rotating the drive rollers may comprise a motor and
power
transmission means operatively interconnecting the motor and drive rollers.
The power
transmission means may comprise a drive chain in engagement with a drive
sprocket on an
output shaft of the motor and driven sprockets on the first and second drive
rollers.
The drive assembly may comprise means for supporting the first and second
drive
rollers at a downwardly and rearwardly sloping angle, so that the bucket is
supported at an
angle which slopes towards its lower end when resting on the rollers. The
assembly may
further comprise means for engaging and supporting a peripheral lip around the
bottom of
the bucket so as to maintain the sloping bucket in a predetermined
longitudinal position on
the rollers. The means for supporting the rollers in a downwardly and
rearwardly sloping
angle may comprise a frame having at least forward and rearward legs mounted
thereto, the
forward leg being relatively longer than the rearward leg so that the frame is
supported at
the downwardly and rearwardly sloping angle.
The leading drive roller may be positioned relatively lower than the trailing
drive
roller, so as to bear against the sidewall of the bucket in areas that are
subject to increased
outward pressure during rotation of the bucket with the material that is being
mixed
therein. The first and second generally parallel drive rollers may be angled
together
CA 02476663 2004-08-04
4
towards the rearward ends thereof, so as to extend at an angle that matches a
predetermined
taper of the sidewall of the bucket.
The drive rollers may comprise non-slip external surfaces fox frictionally
engaging
the sidewall of the plastic bucket in drive relationship therewith. The non-
slip surfaces
may comprise resiliently compressible sleeves mounted externally on the first
and second
drive rollers. The resiliently compressible sleeves may comprise a plurality
of raised ridges
for engaging the sidewall of the bucket, with channels being formed between
the ridges for
receiving water and debris as the bucket is rotated in contact therewith.
The basket assembly may comprise an open framework having a plurality of blade
members mounted thereto. The blade members may comprise upper and lower blade
I S members that are mounted to the framework in diametrically opposed pairs.
The blade
members may extend generally longitudinally on the framework, and the ends of
the blade
members may be bent forwardly in the direction of rotation of the plastic
bucket.
The framework may comprise a plurality of rings having the blade members
mounted internally thereto. The rings may be progressively smaller from top to
bottom so
as to define a taper that corresponds to the taper of the sidewall of the
bucket. The rings of
the basket assembly may be sized to form an annular gap of about 1/2-inch with
the
sidewall of the bucket when centered therein.
The framework of the basket assembly may further comprise a plurality of
longitudinally extending rods. The rods may comprise upper ends that are bent
to form
handle portions for manually lifting the basket assembly. The longitudinal
members may
also comprise downwardly extending strut portions for supporting the bottom
end of the
framework a spaced distance above the floor of the bucket. The basket assembly
may be
constructed of welded metal rod.
These and other features and advantages of the present invention will be
apparent
from a reading of the following detailed description with reference to the
accompanying
drawings.
CA 02476663 2004-08-04
BRIEF DESCRIPTION OF THE DRAWINGS
5 FIG. 1 is a perspective view of a portable mixing apparatus in accordance
with the
present invention, showing the manner in which a standard 5-gallon plastic
bucket is
placed on the drive assembly and the separate mixer basket of the present
invention is then
placed in the bucket so as to mix the mortar, grout or other contents thereof;
FIG. 2 is a front, perspective view of the drive assembly of the mixer
apparatus of
the present invention, showing the arrangement of the drive rollers and their
supports in
greater detail;
FIG. 3 is a rear, perspective view of the drive assembly of the mixer
apparatus of
FIGS. 1-2, showing the roller drive mechanism in greater detail;
FIG. 4 is a perspective view of the mufti-bladed mixer basket of the mixer
assembly
of FIG. l, showing the structure of the mixer basket in greater detail;
FIGS. SA-SB are first and second side, elevational views of the mixer basket
of
FIG. 4, showing the relationship of the upper and lower blades of the basket
and the
associated support structure;
FIG. 6 is a top, plan view of the mixer basket of FIG. 4, showing the
angularly
spaced relationship of the blades thereof in greater detail;
FIG. 7 is a rear elevational view, similar to FIG. 3, showing the manner in
which
the drive rollers engage and rotate the bucket when the latter is set thereon;
and
FIG. 8 is a front, perspective view of the mixer assembly and bucket of FIG.
7,
showing the relationship between the drive rollers and the side of the bucket
in further
detail.
CA 02476663 2004-08-04
6
DETAILED DESCRIPTION
a. Overview
As noted above, the present invention provides an apparatus by which mortar,
grout, plaster and similar materials are be mixed on the jobsite in one or
more ordinary 5-
gallon plastic buckets. The apparatus is inexpensive, efficient and highly
portable.
As can be seen in FIG. l, the apparatus 10 of the present invention includes
two
primary subassemblies, i.e., a drive assembly 12 that rotates the plastic
bucket 14, and a
mufti-bladed mixer basket 16 that is placed within the interior of the bucket.
The bucket 14 is an ordinary 5-gallon plastic bucket, such as are used in
large
quantities as containers for many different types of products, in the food and
construction
industries and elsewhere; for example, 5-gallon buckets are commonly employed
as
containers for paint. The popularity of 5-gallon buckets is due in large part
to the fact that
this is a particularly convenient size for handling most fluid or semi-fluid
materials, which
makes them likewise advantageous for handling the grout, mortar and other
materials with
which the present invention is concerned.
Typically, the buckets are formed of a molded high-density polyethylene
material
that is generally rigid but has a moderate degree of flexibility, and the
majority include a
bale or other form of handle for carrying purposes. Although 5-gallon buckets
can be
purchased new - singly or in numbers - they are most frequently available as a
used item,
after the contents have been emptied for their original purpose. The buckets
are
consequently extremely inexpensive, to the point of being disposable; they
are, however,
tough and durable, and are also very easily cleaned due to the smooth, low-
adhesion
surface of the molded polyethylene material.
The conventional 5-gallon plastic bucket therefore represents an optimal
container
for transporting and handling cement grout, mortar, and similar materials at a
job site.
Moreover it can be obtained for little or no cost. Consequently, by virtue of
its ubiquitous
and disposable nature, the 5-gallon bucket l4 may not be supplied as part of
the mixing
CA 02476663 2004-08-04
7
apparatus per se, but may instead be obtained from other sources, e.g., as an
empty
container collected from other construction activities.
The principle function of the drive assembly 12 is to rotate the plastic
bucket while
supporting it at an optimal angle for mixing purposes. As can be seen, the
drive assembly
includes leading and trailing drive rollers 20, 22 that are rotated by a drive
motor 24 via a
drive chain 26. The drive rollers extend somewhat parallel to one another and
are spaced
apart so as to form something of a "cradle" for receiving and retaining the
bucket 14. The
rollers are supported at a sloped angle by a collapsible stand 30, so that the
bucket 14 will
be supported thereon lying on its side and sloping downwardly towards its
closed bottom.
An idler roller 32, mounted on a raised crossbar 34, engages the annular,
depending rim
around the bottom of the bucket so as to act as a stop that maintains the
bucket in the
proper longitudinal position relative to the drive rollers.
When the bucket is placed on the drive assembly 12, as indicated by arrow 36,
the
rollers 20, 22 contact the generally cylindrical, somewhat tapered sidewall 36
of the bucket,
with the weight of the material in the bucket forcing the rollers into
frictional engagement
therewith. Effective drive engagement is ensured by resilient, tubular sheaths
on the rollers
that increase the frictional engagement with the exterior of the plastic
bucket, as will be
described in greater detail below.
The basket assembly 16 is a separate structure that is configured to be
removably
placed within the interior of the bucket 14. The basket assembly includes a
plurality of
blade members that are mounted to an open framework; in the illustrated
embodiment, the
basket assembly includes generally longitudinally extending upper and lower
blades 40, 42
that are mounted in opposing pairs to a wire frame 44. As will be described in
greater
detail below, the wire frame is formed by a series of longitudinally-spaced
wire rings 46a,
46b, 46c that extend around a common axis but are progressively smaller
towards the
lower end of the assembly, so as to follow a taper that corresponds to the
taper of the
sidewall 38 of the bucket. The rings are joined by longitudinal wire rods SOa,
SOb having
upper ends that are bent to form handle portions 52a, 52b for lifting the
basket assembly
when removing it from the bucket; the lower ends, in turn, project below the
lowermost
CA 02476663 2004-08-04
g
ring 46c to form struts 54a, 54b that space the lowermost ring and blades
above the floor of
the bucket.
As will be described in greater detail below, the blade members of the basket
assembly are mounted internal to the wire rings 46a-c, and the rings are sized
somewhat
smaller than internal diameter of the bucket of each corresponding location so
that a gap
having a predetermined size is formed between the wall of the bucket and the
exterior of
the basket assembly. This allows the basket assembly to rotate relative to and
free of the
plastic bucket as the latter is rotated by the drive rollers, so that the
basket rolls with the
bucket but at a slightly different speed.
When the desired degree of mixing has been accomplished, the bucket is removed
from the drive assembly. The basket assembly is then withdrawn and inserted in
a second
bucket, together with the next batch of material to be mixed. The second
bucket is then
placed on the drive assembly to commence mixing, while the first bucket is
carried to the
application site. In this manner mixing can continue in an almost continuous
manner
without requiring the attention of the operator.
b. Drive Assembly
The structure of the drive assembly 12 is shown in greater detail in FIGS. 2-
3.
As noted above, the drive rollers 20, 22 extend generally parallel to the
cylindrical
axis of the plastic bucket when the latter is placed thereon. However, rather
than being
precisely parallel, the drive rollers are angled together slightly towards
their rearward ends,
at an angle that corresponds to the taper of the plastic bucket so that the
rollers make
contact with the outer wall of the bucket over substantially the entirety of
their lengths;
most plastic buckets have a substantially identical taper, and the slightly
yielding, flexible
nature of the polyethylene material enables the wall of the bucket to flex
slightly so as to
accommodate any minor differences between the taper and the angle of the
rollers 20, 22.
In the preferred embodiment that is illustrated, the drive roller shafts are
approximately 10
I/2-inches long and spaced approximately 9 1/2-inches center-to-center with an
CA 02476663 2004-08-04
9
approximate 1/16-inch taper, i.e., the rollers are 1/16-inch closer together
at the rear than at
the front.
As can also be seen in FIGS. 2-3, the drive rollers have a "stepped"
relationship,
with the leading drive roller 20 being positioned significantly lower than the
trailing drive
roller 22. This is accomplished by mounting the bearings 56 for the shaft 58
of the trailing
roller in pillow blocks atop raised pedestal brackets 60, while the bearings
62 for the shaft
64 of the leading drive roller are supported by pillow blocks atop relatively
shorter pedestal
brackets 66. The height difference is preferably about 2-inches or just
slightly more; in the
illustrated embodiment, the brackets 66 for the leading roller are only 1 3/8-
inches tall and
those for the trailing roller are 3 l/2-inches tall, giving a height
difference of 2 1/8-inch.
Again, this has been found to give optimal performance, with the flexibility
of the
polyethylene or other plastic material allowing the drive mechanism to
accommodate
buckets having slightly different configurations.
The difference in height between the leading and trailing drive rollers
ensures
maximum stability and frictional engagement between the rollers and bucket
during the
mixing operation. During rotation of the bucket (which is in the counter-
clockwise
direction when viewed from the front, in the embodiment that is illustrated in
the figures),
the somewhat cohesive, pasty consistency of the grout, mortar and similar
materials will
cause the material to tend to climb up the trailing side of the bucket and
then fall away
across the interior of the bucket, so that the material typically falls back
into contact with
the wall of the bucket at about the 8 o'clock - 7 o'clock position (assuming
counter-
clockwise rotation). The leading drive roller 20 is therefore located where it
will bear
against the outside of the wall of the bucket in the area where the inner
surface of the wall
will be receiving the impact/momentum of the falling material. The trailing
drive roller 22,
in turn, bears against the wall of the bucket opposite the area where the bulk
of the material
climbs up inner surface as the bucket rotates. The drive rollers thus contact
the wall of the
bucket in the two areas where the maximum force bears against its inner
surface, thereby
stabilizing the bucket and ensuring high contact pressures/frictional
engagement with the
rollers. Moreover, the outward pressures against the wall of the bucket causes
it to tend to
bow outwardly on both sides of each roller in these areas, thus increasing the
surface area
CA 02476663 2004-08-04
5 that is in frictional contact with the drive rollers; for this reason, it is
preferable to employ
rollers having comparatively smaller rather than larger diameters, with a
diameter of about
1 1/4-iniches having been found eminently suitable.
Frictional engagement between the drive rollers and the bucket is further
enhanced
by resilient tubular sleeves 68. The sleeves are formed of a relatively soft,
resilient
10 material having a high coefficient of friction for engaging the slick outer
surfaces of the
plastic buckets, plus good wear and durability characteristics. Furthermore,
the sleeves are
preferably provided with a plurality of raised ribs or ridges, either annular
or spiral, as
opposed to having smooth, plain surfaces; the ribs/ridges form channels for
passage of
water/contaminant material on the exterior of the bucket while still
maintaining frictional
engagement between the ribs and the plastic surface. Moreover, because the
particulate
material (e.g., mortar or cement) is carried into the channels between the
ribs/ridges
together with the water, there is a reduced tendency for the particulate
material (which is
frequently abrasive in nature) to wear against or be pressed into the
resilient material of the
sleeves, thereby enhancing the longevity and effectiveness of the sleeves.
Fiberglass-reinforced irrigation suction hose has been found to provide a
suitable
ribbed, resilient sleeve material for use on the drive rollers of the present
invention. In this
material, the softer, high-friction plastic is supported in spiral ridges by a
harder fiberglass
material, giving an optimal combination of traction and durability. Moreover,
the spiral
configuration of the ridges acts in cooperation with the rotation of the
rollers to draw the
bucket outwardly towards its base, ensuring that the bucket remains firmly
seated on the
drive assembly during the mixing operation. 1 1 /4-inch HD fiberglass-
reinforced suction
hose is suitable for use with drive rollers having the dimensions stated
above.
When the bucket is seated on the drive assembly, the depending, generally
cylindrical lower lip 70 at its lower end bears against the idler roller 32 on
crossbar 34.
The idler roller 32 thus supports and maintains the bucket in the proper
longitudinal
orientation on the drive rollers while creating minimal resistance to
rotation. In the
illustrated embodiment, the roller 32 is suitably a hardened steel roller that
turns on a shaft
72 that is supported on brackets or otherwise mounted to the crossbar; it will
be
understood, however, that other forms of low friction structures and devices
may be used to
CA 02476663 2004-08-04
support the lip of the bucket, such as plastic (e.g., UHMWPE) rollers or
blocks, for
example.
As was noted above, the rollers 20, 22 are driven by chain from the motor 24.
As
can be seen in FIG. 3, the chain 26 engages driven sprockets 74, 76 on the
ends of stub
shafts that extend rearwardly from the leading and trailing rollers, and a
drive sprocket 78
on the output shaft of motor 24. The drive and driven sprockets have relative
diameters
selected to produce the desired drive ratio: As can be seen in FIG. 3, the
drive sprocket is
sized larger than the driven sprockets so as to provide a ratio that steps up
the speed of the
drive rollers relative to that of the motor. Although the sprockets and chain
are shown
exposed in the drawings for ease of illustration, it will be understood that
these components
may be covered with a housing (e.g., formed of sheet metal, fiberglass or
molded plastic)
both for enhanced safety and reduced likelihood of damage from impacts and/or
debris.
In the illustrated embodiment, a preferred drive motor for use in the assembly
is a
12-volt DC automotive windshield-wiper motor. As a class, these motors have
good
torque characteristics and exhibit relatively low voltage draw. Moreover, they
can be
operated from the 12-volt electrical system of a stationary motor vehicle or
from a
comparatively small, rechargeable 12-volt battery (e.g., a trolling motor
battery), thereby
greatly enhancing portability of the assembly. As noted above, the drive and
driven
sprockets provide a ratio that increases the speed of the rollers from that of
the motor, i.e.,
about 50 RPM. The drive chain 26 is suitably a conventional roller chain
having a
configuration matched to that of the drive and driven sprockets. It will be
understood,
however, that other forms of drive motors, such as 110 VAC electric motors,
hydraulic
motors, I/C engines and so on may also be used in some embodiments.
c. Mixer Basket
The structure of the mixer basket assembly 16 is shown in greater detail in
FIGS. 4-
6.
CA 02476663 2004-08-04
12
S As noted above, the basket assembly 14 includes blades 40a, 40b and 42a, 42b
that
are mounted in upper and lower pairs. It will be understood, however, that in
other
embodiments there may be more or fewer blades, mounted in pairs or otherwise.
As can be seen particularly in FIGS. SA-SB, the lower ends of the upper blades
40a,
40b are curved in a direction towards the direction of rotation
(counterclockwise when
viewed from the top), while the upper ends of the lower blades are curved in
the reverse
direction. This both facilitates the mixing action and helps to ensure that
the mixing basket
is "pulled" downwardly into the mortar or other material that is being mixed.
Since the outside diameter of the basket assembly (i.e., the outside diameters
of the
wire rings 46a-c) is smaller by a predetermined amount than the inside
diameter of the
1 S bucket at corresponding longitudinal locations, the basket is free to
develop rotational
motion relative to the latter; specifically, as the bucket is rotated the
basket assembly
rotates with the bucket but at a slightly slower speed. In the embodiment that
is illustrated,
the rings 46a-c define a taper that establishes a substantially constant 1/2-
inch clearance
(when centered) with the correspondingly tapered wall of the bucket.
As was also noted above, the rings are joined and supported by longitudinally
extending wire rods SOa-d, so that the assembly is essentially in the form of
a wire
framework. The upper ends of the longitudinal rods are bent over (e.g., by
about 90°) to
form the handle portions S2a-d that facilitate insertion and removal of the
basket assembly
from the interior of the bucket, while the projecting lower ends form struts
S4a-d that
2S support the lowermost ring a spaced distance above the floor of the bucket
and prevent the
lower ends of the blades 42a-b from dragging thereon. Suitable spacings and
heights for
the rings and longitudinal rods are set forth in the following table,
referring to FIG. SB:
TABLE 1
Dimension (inches)
a. 2.454
b. 5.126
c. 4.124
d. 1.503
CA 02476663 2004-08-04
13
The foregoing dimensions are for an exemplary basket assembly of 1/4-inch wire
rod. It will be understood, however, that the dimensions and configuration of
the basket
assembly may vary in other embodiments.
It is preferable that at least the rings of the basket assembly have rounded
outer
faces where these bear against the inner surface of the bucket, e.g., the
rings and rods may
be formed of round wire rod. As part of the present invention, it has been
found that the
combination of the freely rotating basket assembly and the rounded outer
surfaces of the
rings and rods renders it far easier to remove the basket assembly from the
bucket upon
completion of mixing. By contrast, where flat-surfaced members are employed
for the
I S basket assembly (e.g., ring members having flat outer surfaces) it is
often notably difficult
to remove the basket assembly, in large part due to the tendency of rocks and
other
materials to jam between the basket assembly and the wall of the bucket during
the mixing
operation.
In the illustrated embodiment, the basket assembly is suitably constructed of
welded steel wire, which is strong, highly durable and resistant to abrasion.
In other
embodiments, however, the basket assembly will be formed of other materials,
such as
injection-molded plastic, for example.
d. Collapsible Stand
Refernng again to the drive assembly and the particular one shown in FIGS. 2-
3, it
will be seen that the primary support member of the drive assembly is a
rectangular frame
80 constructed of elongate members 82a, 82b of a suitable material (e.g., 3/4-
inch square
steel tubing), lying substantially in a common plane. The crossbar 34 is
supported from the
frame by a pair of upright members 84a, 84b and is stabilized against loads
from the bucket
by angled base members 86a, 86b. Left and right vertically extending channel
sections
88a, 88b are mounted at the two forward corners of the frame 80. The channel
sections are
sized to receive the upper ends of first and second leg members 90a, 90b, and
are pivotally
CA 02476663 2004-08-04
14
S connected thereto by pivot pins 92a, 92b. The legs are themselves joined to
one another in
parallel, spaced relationship by crossbar 94.
A third leg 96 is stidingly received in a sleeve 98 that is mounted to the
frame bar
82d at the rear of the assembly. A cross member 100 is mounted to the rearward
leg 96 so
as to form a T-shaped handle at the top thereof. A bolt 104 having a T-handle
for manual
tightening/loosening extends through a threaded bore in the sleeve 98, with
the end of the
bolt bearing against and engaging the leg 96 so as to lock the latter in
position. The
forward-to-rearward angle of the mixer stand can be therefore be adjusted by
loosening the
locking bolt 104 and sliding leg 96 through sleeve 98 until the desired length
projects
below the frame 80.
Not only does this adjustment enable the assembly to accommodate
irregularities in
the ground, but more importantly, it allows the angle of the bucket to be
adjusted for
optimum mixing action, depending on both the properties and nature of the
material being
mixed. For example, if a larger quantity of more fluid material is being mixed
then an
increased, steeper angle may be desired, as opposed to a shallower angle when
mixing a
smaller amount of thicker, more cohesive material.
In order to collapse the drive assembly for transportation to another
location, the
locking bolt 104 is loosened and the rearward leg 96 is withdrawn upwardly
from sleeve
98. The frame is then set on its rearward edge, resting on a rearward frame
bar 82d, and
the front legs 90a, 90b are pivoted downwardly and rearwardly until the
crossbar 94 rests
flat against the bottom of frame 80. The rear leg 96 is then inserted through
first and
second sleeves 106a, 106b that are mounted to frame 80 on extensions 108a,
108b, so that
the leg 96 passes beneath cross bar 94 so as to hold the front legs in the
folded position and
prevent them from falling outwardly during transportation.
Thus collapsed, with its legs lying flat against the bottom of frame 80, the
drive
assembly is highly compact and easily transportable, as in the trunk of an
automobile, for
example. Moreover, the middle portion of the cross bar 34 provides a
convenient and well-
centered hand grip to aid in lifting and handling the assembly. As a result,
the mixing
apparatus of the present invention can be transported from one job site to the
next with far
greater ease than prior forms of mixers. Furthermore, in some embodiments one
or more
CA 02476663 2004-08-04
5 of the legs may be provided with wheels for aiding in moving the apparatus
about when it
has been set up.
e. Operation
10 In order to use the apparatus of the present invention, the operator simply
places the
desired amount of mortar, grout, plaster or other material in the bucket 14
and then places
the basket assembly 16 therein, using the handle portions 52a-d described
above. The
bucket and mixing basket are then placed on the drive rollers as shown in
FIGS. 7-8, and
the drive motor is energized. If the bucket has a bale, this can be secured
using a clip (not
15 shown) so that the bale does not flop about as the bucket is rotated. As
noted above, the
drive assembly of the illustrated embodiment rotates the bucket assembly at
about 50 RPM,
which is suitable and effective for mixing these and similar types of
materials.
When the desired amount of mixing has been achieved, the operator simply lifts
the
bucket off of the drive assembly and sets it upright. The mixing basket 16 is
withdrawn
and placed in a second bucket (not shown) that has been filled with the next
batch of
material. The operator carries the first bucket (using the bale, if so
equipped) to the site at
which the material is applied, while the apparatus continues to prepare the
next batch
without requiring any intervention from the operator. When application of the
first batch
of material has been completed, the operator simply carries the bucket back to
the mixing
apparatus, removes the second bucket from the drive rollers, and repeats the
process using
the same or subsequent plastic buckets. In this manner the mixing is
accomplished in an
extremely efficient manner, with little or no wasted time between batches.
When the job has been completed, the mixing basket 16 is simply hosed off, and
the buckets can also be rinsed out and cleaned very quickly due to the
relatively low
adhesion of the plastic material. If any of the buckets have become damaged or
worn to an
excessive amount they can be discarded and replaced with others at little or
no cost. The
drive assembly 12 is likewise easy to clean by simply hosing it off. The drive
assembly is
then rapidly collapsed into a compact package, as described above, ready to be
transported
to the next job site.
CA 02476663 2004-08-04
16
It is to be recognized that various alterations, modifications, and/or
additions may
be introduced into the constructions and arrangements of parts described above
without
departing from the spirit or ambit of the present invention.
