Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
W093/21093 ~ O PCT/U592/03080
Dg~IC~ A~D N~T~OD ~OR O~TLO~DI~ B~L~ MaTBRIA~8
BAC~GRO~ND OF ~EI~E~ Y~
~ ld of I~vo~t~o~.
S This invention relates to a material
delivery/removal system for transporting grain, cement,
and other dry stored material~ from a storage bin, dome
or other lateral enclosure. ~ore specifically, the
present invention relates to a bulk material delivery f
system for u~e with a free standing dome or shell~ e
storage bin which utilizes a rotating drag arm for
pulling the bulk material toward a central outlet.
2. P~ior Art
Bulk storage of materials such as grain, cement,
dry fue.ls and other commodities posas many problems
which ulti~ately affect the availability of food, fuels
and construction materials upon which earh nation's
economy dependæ. These problems range from storage
requirements to special handling needs in material
transport. The most difficult challenges typically
arise when the bulk materials require both a controlled
storage environment and unique handling profile during
loading and unloading in storage areas.
Such materials include cement and similar bul~
2S commodities which must be stored in a dry atmosphere.
Because such materials require total enclosure for
protection from the elements, convenient access for
retrieval is typically limited. Although movable
roo~ing permits direct use of scoop shovels and buckets
to raise the buik màterial to nearby trucks or rail
cars, such facilities and methods are labor intensive
and require a significant capital investment for
equipment and ~pecial construction of buildings. As a
consequence, industrial trends have focused on reducing
3S the cost of storage and handling by simplifying
construction of gtorage areas.
W O 93/21~93 ,~ 240 P~r/US92/03080,
For exam ple, frèe-standing dome structures have
con~bined economical construction with the benefits of
total enclosure. U.S. Patent 3,456,818 illustrates a
dome structure used for storing grains. Bulk materials
are loaded within the dome through a top opening and are
distributed outward by a rotating auger that drags the
grain outward toward the laterally enclosing dome wall.
Thi~ auger is designed to rotate along its longitudinal
axis on top of the grain, as well as rotate radially
around a center support post to provide redistribution
of grain across the 360 degree top surface area of the
grain. This dual rotation of the auger funcl;ions to
maintain the auger in a "floating" configuration on top
of the grain storage surface. The weight of the auger
is carefully selected to enhance this floating
performance as a necessary part of ~he system.
Outloading is accomplished by rotation of the
center support post without the need for rotation of the
auger about its longitudinal axis. An outlet port is
formed in a floor surface below the support post and
includes a subfloor auger which acts as a conveyer to
transport material as it drops by gravity flow from the
interior of the dome. Once the grain has reached its
natural inclination of flow toward the central outlet
port, the auger is activated to drag the remaining grain
toward the center. Eventually, the total contents of
the dome can be swept to the outlet port as the rotating
auger cycles to a horizon~al orientation near the floor
surface.
Although the dome storage structure with transport
system was invented approximately 25 years ago, it has
experienced only limited commercial success. Its
apparent limitation for use with bulk materials having
physical properties similar to grains also inhibits its
utility in other demanding storage needs such as with
cement and other dry goods which are subject to greater
compaction. These latter materials will naturally
WO93/21093 ~ 2~O PCTIUS9~/03080
congeal to a rigid mass under the wPight of the stored
upper layers~ This rigid mass is very difficult to
break up and effPctively blocks gravity flow of stored
materials into the outlet. Because the auger assembly
is designed to float on top of the grain, it has no
significant influence on desired subsurface material
move~ent.
In view of the numerous problems with the
referenced dome storage system, access for movement of
stored materials has generally besn provided by lateral
doors or openings at the base of the dome. These doors
are ~pened and per~it front-end loaders to use
conventional loading techniques with scoop buckets or
similar equipment to transport the materials.
Unfortunately, highly compacted commodities such as
cement do not readily collapse with removal of under
support material. Indeed, a front-end loader may form
a ~avern opening of considerable size within the rigid
base layer of material which could collapse without
warning, causing potentially fatal results.
Earlier patents of this same inventor as
represented by US patent 5,098,247 and European patent
application 91100120.4 disclose an improved system for
outloading bulk materials which utilizes a rotating
2S auger which moves from a vertical orientation,
sequentially to a horizontal position to complete
removal. A significant problem with the use of such a
mechanism arises because of the increased moment arm
required to rotate the extended auger as the center of
mass continues to displace from the vertical support
column. Normal design criteria would dictate that the
power rating of the drive motor for rotating this auger
would be selected to meet the peak power demand, which
occurs when the auger is in a near horizontal
orientation. Alternatively, a more extensive gear box
or transmission system may be adopted to provide the
increased power requirement. Unfortunately, the
'1182~0
WO93/21093 ~ PCT/US~/03080 ~
incr~ased power requirement and or gearing system adds
substantial expense to the overall system cost.
- The increased load required by the greater moment
arm is further compounded by resistance offered by the
compacted bulk material which is to be removed.
Interestingly, these two proble~s complement each other,
because while ~he ~oment arm incraases with greater
inclinatisn of the ~uger, the compaction of the material
also increa~es with such greater inclination because of
the weight of supported material~. Therefore, by the
time the auger reaches the near horizontal position in
ro~ation, the worst conditions exist. Specifically, the
auger is in its most extended orientation and the
material is at maximum compaction.
The problem of increased compaction also arises
with traditional storage structures. For example, U.S.
Patent 2,711,814 discloses an auger useful for cleaning
flat bot oms of a grain tank. Related auger transport
devices have been used in silo storage systems, such as
disclosed in U.S. Patent 2,500,043; 3,755,918; 3,1S5,247
and 3,438,S17. These patents are representative of a
broad range of applications for the transport properties
of an auger within a grain bin. Experience has shown
that such an auger system is not likely to be practical
2S with respect to bulk materials which experience greater
compaction, forming a rigid base layer. It is perhaps
for this reason that much of the prior art technology
utilizing an auger transport system is directed toward
grains and other bulk materials which have less tendency
to compact under pressure. The more flowable condition
of these grains enables the outloading in conventional
storage bins by mere gravity flow.
The auger transport system in these disclosures
functions primarily to redistribute bulk material toward
the center of the storage bin to keep gravity flow in
process throughout the outloading procedure. It is not
intended to be responsive to changing compaction
:;
~11824~ ~
; WO93/21093 PCT/US9Z/03080
conditions that occur as the rotatlng auger progresses
toward the bottom of the bin. In the latter case,
conventional design criteria would again dicta~e that
greater power would be provided by increa~ed motor power
and/or an improved transmission syætem.
-
O~C~8 AM~ Y OF TE~ ~V~N$ION
It is an object of the present invention to providean auger tran~port syst~m which i6 capable of processing
compaction materials such as cement in a rotary drag
~ystem, as well as looser ~aterials such as grains,
without adding extreme cost increase or enhance~d power
demands for the drive motor.
It is a further object of the present invention to
provide a ~aterial transport system useful withir1 a dome
structure having an inclining drag arm which permits the
dome structure to be completely filled, essentially
burying the material transport system used in
outloading.
It is a still further object of the present
invention to provide an auger transport system for bulk
materials stored within a lateral enclosing storage
structure, wherein the transport system can service all
forms of dry, particulate bulk materials, including
compactable materials.
Yet another object of the present invention is to
provide a system for outloading stored bulk materials in
which the outloading structure is generally buried in
a vertical orientation within the bulk ~aterials, yet is
capable of inclining in horizontal rotation for
processing the total guantity of stored materials within
the containing structure.
These and other objects are realized in an
apparatus for removing bulk from a lateral enclosure
wherein the apparatus is designed to be substantially
buried within the bulk material, as opposed to floating
on top of such material. This apparatus includes a
2 ~ 0
WO93/21~93 PCT/US9210308Q~r~,
support colu~n having a top end, a bottom end, and a
vertical axis. A base mount is configured for
attachment between the bottom end of the support column
and a support floor contained within the storage area.
This base mount provides a fixed vertical orientation to
the ~upport column within a central section of the
storage area. First elongate transfer means is coupled
at its ba~e end to the support column for dragging
particular bulk materials along its length to a
dispensing outlet near the base of the support column.
A distal end of the first transfer means is adapted for
attachment to a first support frame, which is also
characterized by a base end, distal end and intermediate
support section. The support frame functions to support
~5 the first transfer means, enabling it to rotate about
the support column. A first drive motor is mounted at
the first transfer means and support frame and operates
to apply a drive force to the first transfer means. A
rotational displacement drive is coupled to the first
support frame for rotating the ~irst support frame about
the vertical axis of the support column. A torque
assist device is coupled at the first elongate transfer
means and includes a moving track configured to engage
a top surface of the bulk material. This assist device
is oriented with respect to the ~irst elongate transfer
means to apply a tangential, forward force along the
rotational path of the first elongate transfer means in
response to resistance of the bulk material engaged
against the moving track element. It is activated as
the ~irst transfer means is inclined substantially
toward a horizontal position, whe~e the moment arm and
compaction cooperate to increase the load imposed on the
rotation drive which rotates the first transfer means
and torque assist device around the support column.
A method for removal of stored bulk materials using
an elongate transfer means such as a rotating drag arm
in a lateral enclosure is similarly dicclosed and
i ~ W093/21093 ~ 82~ PCT/US92/0~80
includes the step of activating movement of a ~orque
assist device coupled at ~he distal end of the first
elongate transf r means to provide additional forward
force to the drag .rm. This torque assist device is
positioned to engage a top ~urface of the compacted bulk
~ater~al and is orien.ed with respect to the first
elongate transfer means to apply a tangential, forward
~orce along ~he rotational path of the first elongate
tra~sfer means in response to resistance of the bulk
~aterial against movement 3f the torque assist device.
Other obje ts and features of the present invention
will become apparent to those skilled in the art, in
view of the following detailed description of prleferred
embodiments, taken in combination with the accompanying
drawings.
~ RI~QN Q~ B~WI~G3
Figure 1 shows a medial cross section of a dome
storage structure utilizing a~ auger transport system
constructed in accordance with the present invention.
Figure 2 illustrates a segmented partial cut-away
section of the support column with attached auger in
vertical orientation at one side thereof.
Figure 3 shows a partial view at the base of the
subject support column, with the auger transport system
in horizontal, ground level position such as would
require use of the torque assist device of the present
invention.
Figure 4 is an end view of an auger transport
syste~ with a torque assist device and second auger
system for clearing a motor path.
Figure 5 is a top view of the system shown in Fig.
.~ 4.
Figure 6 is a front view of the torque assist
device of Fig. 4.
Figure 7 is a perspective view of a torque assist
device for use in the invent~on.
!: .
,~ . .
~, "_
2 1~8~ ~
WO93/21093 PCT/US92/03080~-
Figure 8 is a i~e view of the korque a~sist device
of Fig. 4.
ET~S~D D~8C~IP~Q~ OF ~ INY~N$ION
S Figure 1 demonstrate~ an embodiment o~ the present
inv~ntion in combination with a dome 6truc~ure lO which
operates as a total enclosure for ætored bulk materials
ll. It will be apparent to those skilled in the art
that thæ~e materials have been loaded by a conventional
loading conveyor 12 through and inlet 13 at the top of
the dome structure. This bulk material falls through
spening 14 and spreads across the interior chamber of
the dome, reaching a top level as indicated at item 15.
It is plain to see that the tota~ bulk material ll has
substantially covered a central support column 16 and
attached auger transport devices 17 and 18. The
transport devices 17 and 18 may alternatively comprise
other tranFfer means known to those skilled in the art,
such as bucket or paddle transfer systems.
The dome construction l0 has been illustrated with
the present invention because of its particular
advantage within the hemispherical dome shape wherein
the auger device 17 is comparable to a radial distance
throughout the contained volume of the storage area. In
addition, however, the domed construction is
representative of the more difficult storage problems,
particularly in terms of outloading compacted materials.
Accordingly, this embodiment incorporates the more
stringent of the material transport conditions wherein
access to the contained volumes are limited to an upper
opening 13 and a lower outlet l9. It will be apparent
to those skilled in the art that the same p~incipals
applied with respect to this dome structure could be
applied with respect to any enclosed storage area having
lateral confinement.
The apparatus of the present invention includes a
support column 16 which has a top end 20, and a bottom
WO93/21093 ~11 8 2 ~ O PCT/US9~/0~80
end 21 and a vertical axis 22. The supp~rt column
comprises a steel post which is hollow down its length
except for a pair of deflection plates 23 which divert
~ulk ~aterials tran~ported from the loading conveyor 12
through lateral openings 14 in the support column.
Thi~ support column i~ vertically positioned in a
base mount 24 which is attached between the bottom end
of the 6upport column 21 and a support floor 25
contained within the storage area. This base mount
provides fixed vertical orientation with respect to the
support column within a central section of the storage
area. In the illu~trated ambodiment, this base molmt is
configured for rotational movement about the vertical
axis 22.
Specifically, the base mount includes an annular
converging channel or hopper 26 whose bottom end 29
defines an outlet port which disposes the bulk materials
onto a conveyor belt or other transport means for
carriage to a pickup location euch as transport truc~s
or rail cars. This channeling hopper 26 is supported on
a plurality of rollers or bearing 27 which ride on a
support ring 28 structurally configured to bear the load
of the support column 16 and its attached augers 17 and
18. The support column 16 is integrally coupled to the
channelling hopper 26 with brace members 30 which are
welded at ~he base of the support column on one side and
lower portion of the hopper structure on the other side.
This permits a protective flap 32 to slide along the top
hopper edge 31 and protect against grain falling free of
the hopper. In essence, this flap 32 operates as an
angular sleeve to channel material from the storage area
into the outlet 29 while the hopper is rotating in
concert with the support column.
Similarly, the top end 20 is supported in a
rotational configuration within the top opening 33 of
the dome. As ~et of rollers or bearing 34 stabilize the
support column 16 in vertical orientation. A drive
WO~3/21~93 ~z~ O PCT/~S92/0308
motor 35 and chain drive 36 are coupled at the top of
tha support column 16 and operate as a rotational
displacement means to rotate the support column about
its vertical axis 22.
~The respective base ~ount 24 and upper roller
- ystem 34 cooperate to fix the ~upport column 1~ in a
6turdy, rotational configuration at a central section of
the storage area. Rotation rat~ about the vertical axis
22 is adjusted to the outflow rate of stored material
and is governed by the chain drive 36 and electric motor
3S, which is housed exterior to the dome structure 10.
This enable~ maintenance to be performed with respect to
this drive ~ystem without nsed for access within the
dome interior.
15Attached to the support col~mn is at least one
auger cupport frame 40 and 41. Figure 4 shows a support
column having two such support frames and attached auger
assemblies 17 and 18, further description shall be
directed toward the auger configuration 17 alone. It is
to be understood that a comparable description could be
provided with respect to the second auger 18 which is
illustrated in Figure 1. Figures 2 and 3 do not include
the second auger in view of its symmetrical duplicity
with the disclosure relating to auger 17.
S 25The auger support frame 40 includes a base end 42,
intermediate section 43 and distal end 44. The
assembled configuration of these components forms an
~i elongate truss support span which extends from the top
; end 44 to the bottom end 42 and includes mounting end
plates 45 and 46 with bearing mounts coupled thereto for
Z receiving the respective base and end 47 and distal end
, 48 of the auger 17. This auger 17 is configured for
i rotational movement about its rotational axis 50 and
;~ functions to drag particulate bulk materials along the
j 35 length of the auger toward the hopper 26 and dispensing
outlet 27. The auger support frame 40 oparates to
support th~ auger 17 during this rotational movement and
' W093/21093 ~ 240 PCT/US92/030~ l
11 i
provide means for inclining the auger at varying angles
as it revolves about the support column 16.
The preferred embodiment of the present invention
provides mounting of a rotational drive motor 51 at the
5 distal end 48 with respect to the end plate 46 on the t
auger ~upport frame. This is in direct contrast with
prior art trends of positioning the drive motor on aug~r
transport systems near the support column, and at a base
end of the auger. Disposition of the drive motor 51 at
10 a distal end of ~he auger maintains the motor above ths
top level 15 of bulk material. For example, with full
capacity storage as shown in Figure 1, the drive motor
51 stands above the material level 15 by virtue of its
vertical orientation. During outloading, the auger is
15 gradually displaced in a conical revolution pattern,
cutting away respectively at conical layers of bulk
material. As the aug~r is further inclined away from
the central column 16 (see phantom line examples 54 and
55), the rotational drive motor 51 is always positioned
20 above material storage levels. This preserves life of
the motor and facilitates its continuous operation to
service all stages of outloading.
This is in direct contrast with prior art systems
which depend primarily on free fall of the bulk
25 materials through the outlet. In these prior art
em~odiments, the auger transport system is primarily
functioning to collect a remaining portion of the bulk
materials left around the periphery of the floor wherein
the inclination of stored materials no longer
30 facilitates free fall of the particulate matter to the
outlet. The pres~nt invention comprehends not only the
flowable grain material of prior art auger applications,
but also covers materials such as cement and other
highly compactable substances.
Inclination of the auger 17 is enabled by use of an
axial mount 57 which couples between the base of the
auger support frame 42 and a bottom end of the support
~1182~0
WO93/21093 PCT/~S92/030~.
12
column l~. This stru~-ture permits the auger ~upport
frame to rotate vertically about the axial mount 57 to
enable rotation inclina~ion of the auger and support
frame from (i) a vertical orientation (~olid line
representation of item 17) wherein the auger i5 nearly
parallel with ~h~ axie 22 of the support column, (ii)
through inter~ediate anglas of inclination ~represented
by phantom line drawing 54) to (iii) a substantially
horizont~l orientation (repr~sentation 55) wherein the
auger i5 adjace~t to th~ ~upport floor of the storage
ar~a.
Selection o~ the ~pecific inclination angle is
accomplished by use of a variable suspension means 60
which is coupled between the support column and the
auger support frame and enables various selection and
adjustment of auger inclination by permitting rotational
inclination with respect to the axial amount.
Specifically, this suspension means includes the
æuspension cable 61 which is attached at a first point
of attachment 62 near the top end of the support column.
This cable is next supported on a first pulley 63 which
is attached near the dist~l end of the auger support
frame 44. This cable is further supported on a second
pulley ~4 which is attached to the support column
between the first point of the attachment and the top
end ~O of the support column. A second end of the
suspension cable is coupled to a winch or other drive
syst~m 65 having a fixed location with respect to the
support column.
The winch operates in a conventionaI manner to reel
in and let out suspension cable to selectively incline
the auger at a desired position. The winch operates as
a control means for incrementally advancing the auger
through a series of predetermined inclinations which
increase in angle of inclination with respect to the
support column with each successive 360 degree
revolution of the auger about the vertical axis 22. It
,1
i
,
~,
! ` wo 93/21~93 ~ 8240 PCT/US92/03080
will be apparent that although only two inclined
position~ are reflected in Figure 1, the variety of
inclination angles is continuous from the vertical
orientation shown in olid line for auger 17 through all
intermediate angles to a horizontal configuration
illu&trated as item 55.
Electrical support for ~he respective components is
provided by conventional wiring configurations. For
ex~mple, all wiring 3upport for the rota~ional drive
~otor 35 and winch 65 ~re external to the dome and
enable direct access for maintenance. Electrical
support to the winch and its rotatable configuration as
part of the support column is provided by a sl:ipring
assembly 69. The same conductive slipring provides an
electrical connection identified by dashed line 70 which
extends the length of the support column and passes from
the base of the ~upport column up through a central tube
opening within the auger 17 to the drive motor 51. All
electrical lines are appropriately anchored and shielded
to prevent wear with the anticipated patterns of
movement for both the auger and the support column.
Referring now to FI~S. 4 to 6, the auger 17 and
support frame 40 are shown having a secondary auger 110
attached at the distal end 44 of the support frame 40,
to the side of the drive motor 51. The secondary auger
110 may alternatively comprise other transfer means
known to those s~illed in the art, such as bucket or
paddle transfer systems. The secondary auger 110 is
supported by a secondary support frame 112 in which the
auger 110 is rotatably mounted. The secondary support
frame 112 is secured to the side of the distal end 44 of
the support frame 40 by welding or other suitable means.
A sQcondary rotational drive motor 114 is mounted to the
secondary support frame 112 at t~e proximal or base end
of the auger 110 to the support column 16, to rotatably
drive the auger 110. Since the auger 110 is smaller
WO 93/21~93 ~ 118 2 4 0 PCI/US9~/0308
1~
than the auger 17; the drive motor 114 is
c:orrespondingly smaller than the motor 51.
Although the ~notor 51 will be ~aintained above the
top level $5 of the bulk material under ideal
5 conditions, in practice the motor 51 E;ometimes comes in
contact with the ~aterial and pushes the material in
front of it with no opportunity fox the auger 17 to
access the material and move it out of the storage dome.
The material in front of the motor Sl also strains the
support column drive motor 35 and causes it to operate
inefficiently.
The secondary auger 110 removes material that may
otherwise build up against the motor 51, and moves it
down to the auger 17 for removal. The secondary motor
114 does not experience any substantial material buildup
against it since the motor 114 is relatively small and
allows access to the auger 17. The motor 114 has an
electrical power connection through the auger assembly
and support column similar to the connectio~ powering
the motor S1`. To be effective, the auger 110 should be
mounted to the front side of the motor S1, i.e., the
side pushing against the material during rotation of the
support column. Although mounting of the motor 114 on
the proximal end of the secondary support frame 112 is
preferred, the motor 114 may alternatively be mounted on
the distal end of the support frame 112, if desired.
Figures 7 and 8 disclose a primary feature of the
present invention which consists of a device for
providing additional drive force to move the first
elongat~ transfer means as it encounters increased
resistance with progressive inclination toward the
horizontal orientation. Because the drive motor 35
which rotates the first transfer means is mounted to the
support column 16, each sequential adjustment away from
the vertical support column extends the center of mass
of the first transfer means outward, increasing the
force required to rotate this structure. As the first
WO93/21093 ~. 8 ~ ~ O PCT~US92/03~80
transfer ~eans mo~es substantially toward the
horizontal, such as at inclination great~r than forty
degrees from the vertical axis 22, this increased load
imposes a greater traction against the bulk material and
S greater drag on the drive motor 35. This load is
further increa~-ed by the additional drag encountered ~y
the first transfer m~anG as it moveR against the bulk
material which is now leE~ ~usceptible to gravity Llow.
To overcome the need for introducing expensive
gearing to provide this increased power output to the
first transfer meansl a torgue assist device is coupled
to the frame 40 at the distal end of the first elongate
transfer means. This device includes a moving track 61
which is driven by a motor 62. The track 6l is
configured to engage a top surface of the bulk material
and propel itself across this Rurface to apply a
tangential, forward force along the rotational path of
the first elonqate transfer means in response to
resistance of the bulX material against the moving
track. It is positioned behind the moving auger 17 so
that the track rides on a fresh-cut surface of compacted
material.
The track 61 specifically comprises a rotating
~rack assembly of individual track pads 63 which are
supported on a rotating track carrier 64. At least one
track element 65 (Fig 8) is coupled to one of the track
pads 63 and projects outward from the track assembly 1
to 4 inches to provide a gripping edge which extends
into the bulk material as the track assembly moves along
its surface. It is preferable to have track elements 65
cubstantially separated so that the compacted surface is
not significantly disturbed. In this manner, the fresh-
cut s11rface remains firm and provides traction to the
- 35 track pads and is not merely pushed rearward by the
rotating ~rack assembly. The track element 65 ensures
some grip at this surface to maintain uniform track
f
,
WO93/21093 ~ 8 2 ~ O PCT/US92/0308
16
movement. For most materials, track element spacing
will be at 1 to 2 feet, with a preferred separation at
one and a half feet. For most materials, track element
spacing will be at one to two feet, with a preferred
separation at one and a half faet.
The track assembly is driven by a ~ariable drive
motor 62 which is coupled to the trac~ carrier through
` a drive axil 67 to provide power to rotate the track
carrier and track a6sembly at variable speeds. ~ front
~xil 68 rotates fre~ly and ~upports a forward element of
the track carrier 64.
The track assembly is driven by a variable drive
motor 62 which is coupled to the track carrier through
a drive axil 67 to provide power to rotate the track
carrier and track assembly at variable speeds. A front
axil 68 rotates freely and supports a forward element of
the track carrier 64.
The variable speed is developed by a power
regulator which is responsive to rotational rate of the
first elongate trans f er means about the support column.
This power regulator includes means to adjust the speed
of the track carrier to match the rate of movement of
the first elongate transfer means. These speed should
be m~tched so that torque assist device complements
forces being applied to the first transfer means. If
the speed of the torque assist device were unmatched,
the torque assist device would impose additional drag
(at a slower sp~ed) or would attempt to push drive motor
35 above its intended rate (at higher speeds). In the
latter case, the track elements simply dig into the bulk
material and reduce the effectiveness of the track for
developing a forward fo~ce.
Typical speed for the combined first transfer means
and attached torque assist device is approximately 12
feet per minute. Actual speeds will vary, depending on
type of bulk material involved and the extent of
compaction. In all cases, the selected speed i5 matched
~118~40
- f ` WO93/21093 : PCT~US92/03080
- 17
for the respective drive sy tems of the transfer means
and torgue assist device.
Generally, the elongate transfer means is mounted
to the frame of the firct transfer means such that the
vertical level of the track which engages the surface of
the bulk ~aterial is substantially equal to the vertical
level of the lowest edge of the first elongate transfer
means which i~mediately precedes a path of movement for
the track. This relationship properly positions the
track for engagement with a freshly exposed surface of
bulX material resulting from displacement a surface
layer of material by the first elongate transfer means.
A retractable suspension system 70 is provided to
protect the torque assist device from being damaged by
obstacles or when the elongate transfer means drops to
a lower level than the torque assist device. Because it
is rigidly bolted to the frame 40 of the transfer means,
the small size of the torque assist device will tend to
follow at the fixed elevation of the transfer means and
could incur serious damage if the transfer means
suddenly drops to a lower level. Obstacles may also
arise if the rotating auger of the transfer means passes
chucks of material through its spiral blade, and the
fixed track pads are unable to yield. Therefore, the
suspension system includes means for upward displacement
of the track out of a path of forward movement when an
obstacle is encountered which would otherwise block
forward ~ovement of the track or if the first transfer
means suddenly drops to a lower level. In the
illustrated embodiment, spring e~ements 71 and 72
fulfill this need.
The illustrated embodiment has a further safety
; feature which allows the device to rotate out of the
path of a large obætacle. This arises by attachment of
the device by means of a hinge mechanism 80 which allows
the device to rotate up and out of the path of the
obstacle. Angular adjustment of height is provided by
.,
5^118~0
WO~3/21~93 PCT/US92/030~-
18
a threaded adjustment bolt 81, which is mounted to the
torqua assist device at flange elements 82. The head
portion 83 of the bolt 81 abuts against a stop plate 84
which extends ~rom the ~upport frame 40. Alternatively,
the vertical displacement ran be implemented by slidably
~upporting the torque afisist device on vertical rods.
It will be apparent ~hat numerous variations in
structure can be implemented to apply the inventive
a~pects of this di~closure. For example, Figure 8
depicts the track assembly as including a track section
which is substantially planar along an engaging surface
of ~he bulk material. Although this configuration may
be generally preferred, there may be some types of bulk
materials which would respond equally well to a circular
track or drum. As another example, it will be noted
tha~ the track element i~ lustrated comprises a section -~
of angle iron coupled at one side to the track assembly,
the r~maining side projecting outward from the track
assembly to provide the gripping edge to engage the bulk
material. Other forms of gripping elements may be
readily substituted.
As is illustrated in Figure 1, a second elongate
transfer means 18 may be positioned in opposing
orientation to the first transfer means 17. Its
construction is similar to the first, having a torque
assist device positioned in a trailing orientation with
respect to the second transfer means.
Generally, these variations all embody a common
methodology, represented by the steps of: -
positioning a support column having a top end, a
bottom end, and a vertical axis at a central location of
the storage area;
cecuring a base mount between the bottom end of the
support column and a support floor contained within the
storage area, said base mount providing a fixed vertical
orientation to the support column within a central .:
section of the storage area;
i WO93/21093 2 1 1 8 2 4 0 PCT/US92/030~
attaching to a first support frame a first elongate
transfer ~eans for dragging particulate bulk materials
along a length of the first transfer means toward a
dispensing outlet near the ba~e of the support column,
said first transfer means having a base end and a distal
end;
attaching the first ~upport fra~e at a base end
thereof to the support column with an axial mount for
~nabling rotational inclination of the first transfer
~eans and first support frame from (i) a v~rtical
orientation wherein the first transfer means is nearly
parallel with the vertical axi~ of the support c:olumn,
(ii) through intermediate angles of inclinations, to
(iii) a substantially horizontal orientation wher~in the
first transfer means is adjacent the support flocr o~
the storage area;
coup~ing a first drive motor to the first transfer
means and first support frame, said first drive motor
further including means to apply a drive force to the
first transfer means;
storing bulk material within the lateral storage
area wherein the first transfer means is at least
partially buried within the bulk material with the first
transfer means at an inclination greater than fifty
degrees with respect to the support floor;
commencing removal of the bulk material by
activating the first drive motor on the first transfer
means, thereby assisting free fall along an inclined
flow of stored bul~ materials to an outlet port in the
support ~loor of the storage area;
concurrently rotating the first transfer means with
the acti~ated drive motor about the vertical axis of the
support column to remove a conical volume of bulk
material forming an inclination of exposed surface of
bulk material wherein the torque assist device is
capable of generating traction against the bulk
material, which will generally be of greater than forty
W~93/21093 2 1 1 8 2 ~ O PCT/US9~/0308~
degrees with respect to the vertical axi , depending on
material properties;
positioning the fir t transfer means in an inclined
orientation capable of generating traction between the
torque assist device and bulk material such inclination
being generally at less than fifty degrees with respect
to the ~upport floor~ depending on material properties;
acti~ating movement of a tor~ue assist device
coupled at the distal end of the first elongate transfer
means and positioned to engage a top iurface of the
compacted bulk material, said assist device being
oriented with respect to the first elongate transfer
means to apply a tangential, forward force along the
rotational path of the first elongate transfer means in
response to resistance of the bulk material against
movement of the torque assist de~ice.
sequentially and incrementally lowering the first
transfer means with each successive revolution to remove
succe~sive layers of bulk material.
The significant advantage offered by the addition
1~ of the torque assist device to the disclosed system has
been confirmed by experimental results. For example, it
was discovered that to generate 2 horsepower of drive
from a top drive motor 35 rated at 2 hp, out to the end
of the first transfer means when horizontally disposed,
requires $20,000 of special gearing for a conventional
dome storage area. This cost is eliminated by
attachment of a torque assist device at a cost of $3000.
This translates to a savings of Sl9,000. ~.
It is to be understood that the foregoing
description of preferred embodiments is merely by way of
example and is not to be construed as limiting with
respect to th~ iollowing claims.
,.,
r
... . . .
: ~7~
