Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Bac';cround of th~ Inv2n.ion
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The presen, invention relates to a concrete
mi~ing sys~em, and more partieularly relates to im-
provements in large por'able conerete mixing sys,ems
having a mixing eapaeity greater than twenty clbie
feet 2nd embodying an u~right mixing ehamber ha-~ing an
inlet in the top thereof for permiiting th~ in.ro-
duetion or mi~ture m2terizls and an outlet at the
bottom thereof ror seleetively permitting the aiseharge
o~ a we eoncrete mix,ure. This general ~ype o~
mixer is partieularly exemplified by that sho-in in
Hall U.S. Patent 3,759,492, granted 18 Se~tel~ber, 1373.
The fea~ures of such upright por~aD'e eon-
erete mixing systems mus, resolve several f2c,0rs,
which inherenily flow out OL- the competing eon,iderations
of portability and eap2cit~, such as erfieiency,
installation time, eleanup time, space re~uire-~nts,
ease of operator aecess, and ease of delivery OL the
- wet conerete mixture to transport deviees.
Previous portable eonerete mixers having
their eonere,e mi~ materials inlet at a sufficiently
low elevation to per~it easy operator access ~ereto
either saerifiee system eapaeity or have their eoncrete
dischar~e outlet at a very low elevation with ~espect
to the wor~ing surface. In the latter instance, sueh
a system irevitably e3mplieates tlle process o dis-
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charging the wet concrete mixture into transport
devices such as trucks, carts and the like, since the
low elevation of the outlet precludes the movement of
transport devices upon the working surface to a position
beneath the outlet. Accordingly, such systems require
complex means such as conveyor belts for delivering
the concrete mixture to concrete transport devices.
Such delivery devices inherently require an inordinate
amount of installation time, cleanup time and working
space and thereby limit the mobility and efficiency of
the mixing system.
Conversely, previous concrete mixing systems
having their discharge outlet sufficiently spaced
above a horizontal working surface as to permit the
movement of transport devices upon the working surface
to a position beneath the discharge outlet, either
sacrifice system capacity or have their inlet spaced
so far above the working surface as to preclude an
operator standing upon the working surface from intro-
ducing concrete mix materials tnereto. The latter
systems require the time-consuming erection of a
working platform to permit operator access to the
mixer inlet, and/or some form of bulky elevator to
raise the mixing materials to the level of the inlet.
~hat is needed, therefore, and what the
present invention provides, is a portable upright
concrete mixer having a relatively large capacity that
is compact, has an inlet for introducing mixing materials
located sufficiently proximate a working surface to
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permit easy operator access thereto, has a discharge
outlet sufficiently above ~he working surface as to
permit movement of transport devices on the wor~ing
surface to a position below the outlet, and whlch
provides enhanced portability by requiring a minimum
of installation, cleanup and transport efforts.
Summary of the Invention
The present invention relates to improvements
in portable concrete mixing systems and is particularly
directea to upright concrete mixing systems having a
loading inlet at the top and a discharge outlet at the
bottom thereof. More specifically, the concrete mixing
apparatus of the present invention comprises an upright
mixing chamber having a top and bottom; inlet means, having
a top,attached to said mixing chamber for permitting the
introduction of concrete mix materials in said mixing cham-
ber; mixing means ~ithin said mixing chamber for blendingly
combining said mix materials with one another so as to form a
concrete mixture in said mixing chamber; outlet means proxi-
mate the~bottom of said mixing chamber for selectively
discharging said concrete mixture from said mixing chamber;
support means connected to said mixing chamber for engaging a
horizontal working surface and supporting said mixing cham-
ber in a lowered upright position with the bottom thereof at
a first predetermined distance above said working surface to
facilitate access to said inlet meansi and lifting means
connected to said mixing chzmber for selectively raising said
mixing chamber to a raised upright position, wi~h the bottom
thereof at a second predetermined distance above said work-
ing surface greater than said first predetermined distance,
so as to provide sufficient clearance between the bottom of
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said mixing chamber and said wor~ing surface to permit
movement of a concrete mixture transport device to a position
on said working surface beneath said outlet means, said lift-
ing means comprising a plurality of members movable with
respect to one another in such a manner that such plurality
of members push upwardly against said mixing chamber during
such movement, means for energizing said members, and means
for continuously maintaining said upright mixing chamber
in uprishi orientation during said lifting and said discharg-
~0 ing.
An object of the present invention is to provide
a portable concrete mixing system that is compact without
thereby lowering the mixing capacity. The preferred embodiment
of the present invention provides a mixing capaci~y of up to ~
twenty seven cubic feet while requiring less than ~ifty per
cent of the working surface required by comparable mixers.
Another objective of the present invention is to
provide operator access to a top-loading inlet without thereby
necessitating the erection and cleanup of a loading platform
or load elevator. The preferred embodiment of the present in-
vention includes means for supporting the mixing chamber suf-
ficientlv proximate a horizontal working surface as to permit
an operator standing upon that working surface to have ready
- access to the top-loading inlet thereof.
Another objective of the present invention
is to eliminate the need for a conveyor to hoist the
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concrete mixture discharged from the bottom of the
mixing chamber to the height of a mixture transport
device while simultaneously eliminating the cleanup
- time and installation labor required for such con-
veyors. The preferred embodiment of the present
invention provides a discharge outlet located sufficient-
ly above a horizontal working surface so as to permit
the movement of transport devices upon the working
surface to a position beneath the discharge outlet.
-A primary feature of the present invention is to
provide a lifting apparatus for selectively raising the
upright concrete mixing chamber from a lowered loading
position to a raised discharge position. In the preferred
embodiment of the present invention an integral lifting
apparatus is provided which allows the mixing assembly
to be raised above the working surface without neces-
sitating an elevator pit therefor.
Another feature of the present invention is
to provide a drive means for providing continuous
rotary motion for a blender within the mixing chamber,
which is selectively engageable to the lifting ap-
paratus thereby also providing lifting power. In the
preferred embodiment of the present invention an
electric motor is capable of simultaneously providing
rotary force to the blending paddles and to a hydraulic
pump. A manually-controllable valve is provided for
selectively pumping,hydraulic fluid under pressure
to a lifting cylinder or relieving the pressure, thereby
raising or lowering the lifting apparatus.
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Yet another feature of the present invention
is to provide a lifting apparatus which maintains the
mixing chamber in an upright orientation throughout
the lifting process in order to prevent mixture spillage
therefrom. In the preferred embodiment of the present
invention an integral hinged parallelogram lifting
assembly raises the mixing chamber to a discharge
position without thereby tilting the chamber.
A further feature of the present invention is
to releasably lock the mixing chamber in its raised
position to insure against accidental lowering of the
mixing chamber. In the preferred embodiment of the
present invention a mechanical latch is provided which
releasably locks the parallelogram lifting assembly
lS when the mixing chamber is in its raised discharge
position and thereby prevents any downward movement of
the mixing chamber~
A further feature of the present invention
is to provide an adjustable outlet chute for discharging
the wet concrete mixture from the mixing chamber at a
- pluraliiy of elevations above the working surface and
at a plurality of distances spaced from the mixing
chamber. In the preferred embodiment of the present
invention a foldable discharge chute is provided which
can be used to discharge the wet concrete mixture from
the mixing chamber in either a folded or extended
form thereof. I
Further features and advantages of the
present invention will become apparent and the full
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nature of the invention will be more readily under-
stood from the accompanying drawings and the following
description and claims.
Brief Description of the Drawings
FIG. 1 is a perspective view of the pre-
ferred embodiment of the present concrete mixing
system with the mixing cham~er elevated to its raised
discharge position.
FIG. 2 is a perspective view of the pre-
ferred embodiment of the present concrete mixing
system with the mixing chamber elevated partially
toward its raised discharge position and showing the
maintenance of an upright orientation of the mixing
chamber throughout the lifting process.
FIG. 3 is a perspective view of the pre-
ferred embodiment of the present concrete mixing
system with the mixing chamber being supported in a
lowered position proximate the working surface to-
provide operator access to a detachable input hoppe`r.
FIG. 4 is a schematic diagram of an exem-
plary hydraulic power circuit for operating the lifting
apparatus and shows an electric motor providing con-
tinuous rotary motion to the blending drive shaft and
to a hydraulic pump.
Detailed Description of the Invention
With particular re~erence to FIG. 1, a
preferred embodiment of the invention is set forth
wherein 20 is a horizontal base member in engagement
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with a horizontal working surface indicated generally
as 21. A rectangular frame member 22 is horizontally
mounted on the base member 20.
An upright member 24 is rigidly mounted on
the front end of the frame member 22 and extend~
perpendicularly therefrom. The upright me~ber 24
receives bracing support from a pair of diagonal arms
26 and 27 which are connected at one end to the top
~ thereof and at the other end to the rear of the frame
member 22.
Referring now also to FIG. 3, a mixing
chamber 28 has a support member 30 extending down from
both sides thereof for supporting the mixing chamber
in a lowered position at a first predetermined dis-
tance above the horizontal wor~ing surface 21. Adetachable input hopper 32 is mounted on the top of
the mixing chamber 28 and has a conventional pivotable
inlet 34 mounted on the bottom thereof for selectively
introducing concrete mix materials into the mixing
chamber 28. The pivotable inlet 34 can be pivoted to
a plurality of open positions by moving lever 38 in
the direction indicated by arrow 40. As is generally
indicated by a dimensional arrow 36 (FIG. 3), the top
of the input hopper 32 is sufficiently proximate
the working surface 21 when the mixing chamber is in
the lowered position as to permit an operator standing
upon the working surface to introduce concrete mix
materials into the mixing chamber 28 via the input
hopper 32.
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It should be noted that the input hopper
32 is detachably mounted by sleeves 33 to the mixing
chamber 28, which permits its removal prior to the
elevation of the mixing chamber 28 and thereby permits
the mixer to be operated at site locations which impose
vertical height restraints.
A foldable discharge chute 84 is mounted on
the bottom front surface of the mixing chamber 28 proximate
a discharge door 86. The chute 84 is shown in its fully
extended position in FIG. 1 and is used to conduct the
wet concrete mixture from the mixing chamber 28 to a
transport device such as a truck, trailer or the like
positioned thereunder upon the working surface 21. As
is best seen in FIG. 1, the fully extended discharge
chute 84 conducts the concrete mixture to a predeter-
mined height 83 abo~e the working surface 21 and a pre- -
determined distace spaced from the front surface of the
mixing chamber so as to discharge the mixture into a
transport device having a complementary height and width.
20' The chute 84 is shown in its folded position
in FIGS. 2-3 and it will be seen therefrom that the
folded chute has a suitable opening formed therein that
permits gravitational discharge of the wet concrete
mixture therethrough at a different height above the
working surface 21 and at a different distance spaced
from the front surface of the mixing chamber 28. This
feature permits the discharge chute to be varied to
accomodate transport devices having varying heights and
widths.
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Hence, when the mixing chamber 28 is in
its lowered position, as shown in FIG. 3, an operator
standing upon the working surface 21 can easily load
concrete mixing materials manually into the input
hopper 32 and thereafter use lever 38 to introduce a
predetermined amount of the materials into the mixing
chamber 28. It is important to note that the operator
has free access to the input hopper while standing
upon the horizontal working surface without any
requirement for a loading platform or elevator for
hoisting the mix materials to the inlet.
As is best seen in FIG. 1, a plurality of
blending paddles 42 are mounted in the mixing chamber
28 on a drive shaft 43 for rotary motion therewith. An
electric motor 44 (shown in phantom) is mounted on the
back of the mixing chamber 28. An external power source
can be connected to the motor 44 via a receptacle box 46
and a switch 48 to energize the motor and provide con-
tinuous rotary motion through reduction gearing 49
and drive belts 51 to the drive shaft 43 and thereby
cause the blending paddles 42 to rotate within the
mixing chamber 28. A liquid and dry concrete mix materials
can be introduced into the mixing chamber 28 where they
will be blended by the rota~y action of the blending
paddles 42 and thereby provide a wet concrete mixture.
The blending paddles 42 are shown for purposes
of clarity as being rotated around a horizontal axis.
It will be understood, however, that the blending paddles
42 may alternatively be rotated about an axis perpen-
dicular to the top and bottom of the mixing chamber
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28 and include a flexible portion in contact with thesides of the mixing chamber so as to sweep away any mix
- materials adhering to the mixing chamber surfaces and
insure that the mix materials will be thoroughly blended
with the liquid.
Still referring to FIG. 1, the electric motor
44, when energized, also provides continuous rotary
motion through the reduction gearing 49 and drive belts
51 to a hydraulic pump 50 (shown partially) for reasons
hereinafter described.
A plurality of elongate members 52 are pivotably
mounted at one end to the rectangular frame 22 and
at their other ends are pivotably mounted to the bottom
of the mixing chamber 28 so as to form a parallelogram
that is generally horizontal when the mixing chamber is
in its lowered position as shown in FIG. 3, and generally
vertical when the mixing chamber is in its raised
position as shown in FIG. 1. A pair of fore-and-aft
arms 54 and 55 (best seen in FIGS. 1 and 2) spaced
inwardly of diagonal arms 26 and 27 are pivotably con-
nected at their lower ends to the rear of the frame
- member 22 by a pivot link 53 (FIG. 1) and are pivotably
connected at their upper ends to the lowest and most
forward portion of a lever arm 56 by means of a second
pivot link 58. The upper end of the lever arm 56 is
pivotably connected to the bottom of the mixing chamber
28 by a third pivot link 60.
A cylinder 62 is pivotably connected to the
rear of the frame member 22 at the pivot link 53 and
houses therein a piston having a piston rod 64. The
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upper end of the piston rod 64 is pivotably connected
to the lever arm 56 by a fourth pivot link 66 offset
from the second pivot link 58.
When the piston rod 64 is forced for~ardly,
it will cause the lever arm 56 to hingedly move upwardly
from its folded association with the fore-and-aft arms
54 and 55 and thereby force the mixing chamber 28 to
move in the direction shown by arrow 68 in FIG. 2.
This lifting action will also cause the elongate members
52 to pivot from their first generally horizontal
position (as shown in FIG. 3~ to a second generally
vertical position (as shown in FIG. 1) to support the
' mixing chamber 28 in its raised upright discharge position.
It will be seen that this translational-type lifting by
pivoting the elongate members 52 concurrently with the
lifting of the mixing chamber 28 maintains the mixing
chamber in an upright orientation throughout the raising
cycle and thereby, in addition to providing a highly
efficient lifting mechanism which does not require an
elevator pit, precludes tilting of the mixing chamber 28
and prevents spillage of the wet concrete mixture through-
out the raising cycle.
The two forward elongate members 52 (best
shown in FIGS. 1 and 2) have a cross bar 70 integral
thereto. A latching arm 74 extends pivotably outward
from the upright member 24 and has a downwardly pro-
jecting dog 72 disposed thereon for engagement with the
cross bar 70 so as to releasably lock the elongate
members 52 as indicated in FIG. 1 whèn the elongate
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members have been pivoted to their vertical position.
This feature prevents accidental lowering of the mixing
chamber 28 from its raised upright discharge position
and thereby guards against injury to the operator should
there be a failure of the lifting mechanism.
Referring generally to FIG. 1, and more
particularly to the schematic view provided by FIG. 4,
a three-position valve 76 is mounted on the back surface
of the mixing chamber 28 and serves, in its neutral
position, to receive hydraulic fluid being pumped there-
to from the reservoir 78 by the continuous pumping
action of the hydraulic pump 50 and to recycle this
fluid back to the reservoir 78. The three-position
valve 76 therefore permits the continuously activated
motor 44 to simlltaneously provide rotary motion to both
the hydraulic pump 50 and the blending paddles 42.
However, when the lift actuator arm 80 of the three-
position valve 76 is moved in one direction from its
neutral position, the three-position valve will permit
the hydraulic pump 50 to pump the hydraulic fluid there-
through to the botto~ portion of the c~linder 62 forcing
the piston to travel upwardly and thereby raise the
mixing chamber 28 from its lowered position sh~wn in
FIG. 3 to its raised discharge position shown in FIG. 1.
The upward movement of the piston will also cause any
fluid trapped in the upper end of the cylinder 62 to be
returned to the reservoir 78 via a bleed hose 82, and
will pivot the elongate members 52 from their horizontal
positions to their vertical positions.
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In this regard, it should also be noted that
the three-position valve could be manipulated to raise
and hold the mixing chamber 28 at any of a plurality
of heights between its lowered mixing position and its
raised discharge position to further accomodate varying
forms of concrete mixture delivery devices. In such
case, additional folding chute elements, flexible units,
or telescoping units could be added to the discharge
chute 84 in order to further increase the flexibility of
the discharge mechanism.
When the discharge has been completed, the
locking mechanism for the elongate members 52 can be
released by moving the latching arm 74 in the direction
indicated by arrow 100 (FIG. 1). Thereafter, as best
seen in FIG. 4, the lift actuator arm 80 can move the
valve 76 in the opposite direction from the neutral
position to allow the weight of the mixer to force the
hydraulic fluid to return from the cylinder 62 to the
reservoir 78. Referring to FIG. 1, this bleeding action
enables the piston rod 64 to retract toward the rear
of the cylinder 62 causing the lever arm 56 to hingedly
move downward towards a folded position with respect
to the fore-and-aft arrns 54 and 55 and thereby pivot the
elongate members 52 and the mixing chamber 28 in the
direction indicated by arrow 102 (FIG. 1).
As the elongate members 52 begin to pivot
downwardly, the impingement of the foldable chute 84
with the upright member 24 causes the foldable discharge
chute 52 to return to its folded position. ~hen the
mixing chamber 28 has been sufficiently lowered from its
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discharge position to enable its support members 30
to engage the working surface 21, the lift actuator arm
80 is returned to its neutral position thereby completing
the lowering process. At this time, fluid pumped to the
three-position valve 76 will be recycled back to the
reservoir 78 in a recirculating fashion.
I.t should be noted that a pair of rectangular
slots referred to generally as 104 are formed in the
support members 30. The walls forming the slots 104
are of sufficient strength and configuration as to
permit the tines of a forklift to extend therethrough
and to raise the entire concrete mixing system for
transportation to alternate work sites and, hence, this
feature further enhances the mobility of the portable
concrete mixing system. It should-be further noted that
these slots eliminate the need for a support pallet and
thereby, in addition to enhancing mobility, permit the
mixing chamber to be supported more proximate the working
surface 21 than would be possible if a support pallet
was required.
The terms and expressions which have been
employed in the foregoing abstract and specification are
used therein as terms of description and not of limit-
ation, and there is no intention in the use of such
terms and expressions, of excluding equivalents of the
features shown and described or portions thereof, it
being recognized that the scope of the invention is
defined and limited only by the claims which follow.
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