Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Background of the_Invention
This invention relates in gen~ral-to conveyiny systems
for moving quantities of granular~ pulverized or fluid material
from one point to another and, more particularly, to systems
in which the feeding member is helical in form.
Conveying systems comprising rotating helical means
encased in a long flexible tube are well-known in the prior
art, as disclosed, for example, in United States Patent
No. 3,381,801, issued May 7, 1968 to B~ Ras~oin, in which a
flexible core is disposed within the rotating helix in fixed
axial relationship to the enclosing flexible tube. Such
systems are~used, for example, for filling freight cars or
trucks with pulverized coal or grain from stockpiles of the
same, or for conveying such materials from one point to
another during processing.
A system of the type disclosed by Rastoin has the
disadvantage that a portion of the material to be conveyed tends
to fall down between the rungs of the rotating helix, causing
a loss in efficiency of the system. Moreover, it may be
fairly expensive to manufacture a flexible tube including a
fixed axial coxe of the type required by Rastoin. In addition,
operation of the system requires constant monitoring to
prevent the output container from overfilling.
Su~mar~ of the Invention
I-t is, therefore, the principal object of this
invention to provide an improved conveyor system employing
a rotary helix for granular, pulverized or fluid material.
A more specific object is to provide a conveyor system which
is more efficient than prior art systems of a similar type.
Another object of the invention is to provide a system which
is cheaper to build and install khan similar prior art systems.
Still another object of the invention is to provide a system
o~ the type described which is operable on a semiautomatic
basis, without the need for constant control by an operator
to turn the motor on and off.
These and other objects are realized in accordance
with the present invention in a conveyor system for yranular,
pulverized or fluid material, which includes a long, flexible
helical coil spring driven to rotate inside of a flexible
tube in which rungs of the helical spring are equipped at
spaced-apart positions with flat semicircular inserts known
as "portable flights 1l of any solid material, such as metal
or plastic, disposed in parallel relation to enhance the
pick-up and delivery of material by the coils. In preferred
example, the inserts take the form of shallow semicylindrical
cups, each formed of a pair of semicircular plates coupled
together by a semicylindrical side wall. The insert cups are
bolted to one rung in every few, the orientation of the
inserts being in staggered angular relation along the length
of the helical spring. For example~ assuming the first
portable flight insert to be disposed in a given reference
position, the next in order will be rotated in a horizontal
plane through an angle of 120, the third through an angle
of 240 and the fourth will be aligned with the first. It
will be understood that the number of rungs between each pair
of portable flight inserts and their specific angular
orientations are matters of choice which can be varied
according to the requirements of each system.
In operati~n, one end of the tubular conveyor is
thrust into a pile or container o~ source material, which is
conveyed to an output chute by the rotating helical spring
modified by the portable flights o~ the present invention.
Assuming that the output chute leads into a collecting container,
the material accumulates in a pile, above which is disposed
a metal paddle or deflection ring mounted on the depending
extension of a toggle switch. When the material collected
in the pile rises to a preselected reference level, the
paddle or deflection ring is pushed up, operating the toggle
switch to turn off the motor, so that the conveyor ceases to
operate. When the pile decreases below the reference level,
the paddle or deflection ring returns to its origina~ position,
operating the toggle switch to turn on the motor.
A particular advantage of the present invention is
that it greatly increases the efficiency of the conveyer
system by reducing the amount of material which falls back
through the coils of the rotating helical spring during
operation of the system.
Another advantage of the disclosed conveyor system
is that it is relatively inexpensive to manufacture and
assemble, in that the axial core required in certain prior
art systems, such as that of Rastoin Patent No. 3,381,801, is
eliminated~
A further feature of the invention is that it is
adapted for semiautomatic operation, requiring minimum control
by an operator.
Accordingly, there is provided:
A conveyor system f~r moving granular, pulverized or
fluid material from a first position to a second position,
which comprises in combination: an elongated flexible tube
including means for receiving said material at one of said
positions and means for expelling said material at or near the
other said position, a flexible helical spring enclosed in
said tube and extending coaxially along the length of said
tube, means for driving said helical spring to rotate about
its longitudinal axis relative to the inner surface o~
said tube, said flexible helical spring including a plurality
of portable flights including substantially plane members
inserted between adjacent coils of said helical spring at
spaced-apart positions along the length thereof, for
continuousl~v picking up said material at said receiving means
and delivering said material to said expelling means when said
sprin~ is driven to rotate about its axis.
There is also provided:
In combination with a conveyor system comprising
; electrically driven means for picking up granular, pulverized
or fluid material from a first position and expelling said
material at a second position, driving means connected to a
source of power for driving said electrically driven means,
mea.ns for controlling said driving means which comprises in
combination: electromechanical switchin~ means having an "on"
position and an "off" position connected to said driving means,
an elongated flexible lever coupled at one end to said
switching means whereby deflection of said lever in one
direction moves said switching means from "on1' to "off"
position, and deflection of said lever in the opposite
direction moves said lever from "off" to "on" position, means
mechanically coupled to said lever and disposed adjacent
said second position for deflection at a preselected level of
material collected at said second position, whereby to turn
said switching means to "off" position when said material
is above a preselectecd level, ancl to turn saicl s~itching means
to "on" position when said material is below said preselec-ted
level.
-- 4 --
There is fu~-ther provided:
A conveyor system for moving granular, pulverized
or fluid material from a first position to a second position,
which compris~s in combination: an elongated flexible tube
including means for receiving said material at one of said
positions and means for expelling said material at or near the
other said position, a flexible helical spring enclosed in
said tube and extending coaxially along the length of said tube,
means for driving said helical spring to rotate about its
longitudinal axis relative to the inner surface of said tube,
said flexible helical spring including a plurality of portable
flights inserted between adjacent coils of said spring in
repetitive serial relation at spaced-apart positions along
the length of said spring, each of said portable flights
comprising a pair of semicircular disks of substantially
rigid material connected at the.ir external peripheries by a
semicircular wall, forming between them a shallow semi-
cylindrical cup inserted internally over one of the rungs of
said spring, and means for securing said cup to said rung in
a plane transverse to the principal axis of said spring for
continuously picking up said material at said receiving means
and delivering said material to said expelling means when
said spring is driven to rotate about its axis.
These and other objects, features and advantages
will be apparent to those skilled in the art by a study of
the attached drawings with reference to the detailed specification
hereinafter.
Brief Description of the Drawings
FIG. 1 is an overall showing of a helical coil spring
conveyor system in accordance with the present invention in
which the coils are modified to include inserts called portable
flights;
-- 5 --
FIG~ 2 shows the conveyor tube of FIG~ 1 including
details of the helical coil spring including the portable
flights of the present invention;
FIG. 3 is an enlarged portion of the helical coil
spring of the pxesent invenkion showing the portable flights
in place;
FIGS~ 4A and 4B show the upper and lower surfaces of
a portable flight member of ~e present invention screwed into
place on a coil rung;
FIG~ 4C is a perspective showing of a portable flight
insert in accordance with the present invention, in place
on the coil rung;
FIGS~ 5A and 5B are enlarged perspective showings,
from the bottom and top respectively, of the paddle and
microswitch combination of FIG~ l; and
FIGS~ 6A and 6B of the drawings show, in perspective
and top view respectively, a partial modification of the
combination disclosed in FIGSo 5A and 5B, in which a deflection
ring and lever system replaces the paddle. In FIG. 6B, the
chute 7 and switch assembly 14,15 have been removed for a
clearer view.
Detailed Description
Referring in detail to the drawings, there is shown
in FIG. 1 a conveyor system 1 in accordance with the pres~nt
invention, a principal element of which is a coil spring 2,
which in the present illustrative embodiment is, say, 36 feet
long, and is formed of stainless ste~l wire 16" thick, the coils
of which have an overa]l outer diameter of 13~" and a pitch of
138" between the centers of the windings.
Referring to FIG. 2, the upper end of the spring 2 is
fi~ed to the outer bushing 5a, which .is welded or otherwise
secured to a motor driven inner bushing 5b, the latter being
secured to the shaft 4a of a conventional motor 4 by, for example,
a setscrew 5c. In the present embodiment, the motor 4 has a
rating of several horsepower, although it will be understood
that the horsepower rating will depend on the weight of the
material to be lifted and the speed at which it is to be conveyed~
Upon assembly, the outer and inner bushings 5a,5b are
enclosed in a cylindrical metal housing 13, of stainless steel
or the like, having an inner diameter just exceeding 15g" and an
outer diameter, say f 1-". ~t the upper end of metal tubular
housing 13 is an annular flange 13a which is screwed or
otherwise secured to the annular flange 4b of the motor housing
4.
The coil spring 2 is surrounded coaxially by a
flexible tubular housing 3, which, in the present embodiment,
is of a flexible plastic material, such as nylon, 158" in outer
diameter, having a wall thickness of ll6" and extending
coaxially along the length of coil spring 2. It will be under
stood that the flexible tubular housing 3 can be formed of any
other plastic material, such as high density polyvinylchloride,
or alternativel~ of a flexible metal conduit, such as corrugated
stainless steel, or any of the other types well-known in the
art. At its upper end, the flexible tubular housing 3 is
welded or otherwise secured to the inner perimeter of metal
tubular housing 13.
The lower end 6 of the flexible tubular housing 3
terminates in a probe comprising a series of slats with
intervening slots 6at extending to a depth oE about 6" in a
directi.on pa.rallel to the pxin~ipal axis of flexible tubular
housing 3.
.
About 8" below the motox houslng 4 on the metal
tubular housing 13, just below the lower end of bushing Sa,
is centred an output chute 7 which takes the form of a tube,
which may be of the same material as the external tubular
housing 13. In the present embodiment, the chute 7 is, say,
4" in outer diameter, 16" in wall thickness and several feet
long, being downwardly disposed at an angle of, say, 60
to the principal axis of metal tubular housing 13, although
it will be understood that in a practical embodiment the
angular direction and the length and width dimenslons of output
chute 7 may be adjusted in accordance with the physical
requirements of the site.
A particular feature of the present embodiment is the
presence of a series of attachments 10 called "portable flights",
which are disposed in spaced-apart positions along the length
of the coil 2, in the manner indicated in FIGS. 2 and 3
of the drawings. In the present embodiment, as shown in
FIGS. 4A, 4B and 4C, the portable flights 10 each comprise
a pair of substantially parallel semicircular plates lOa and lOb
of nylon or similar plastic material, about 121" in diameter and
1 " thick. These are welded or otherwise secured to the ends
16
of a semicylindrical sidewall lOc of the same wall thickness,
forming therewith a cup 158" in outer diameter, 76" in overall
depth and S " in inner depth. Each of the portable flights 10
16
is fitted snugly over one of the rungs of the coil spring 2,
as shown in FIGS. 3, 4A, 4B and 4C, and is securely screwed
into place by two nylon screws lOd and lOe. It will be
understood that the portable fliyhts 10 can be formed of
any suitable substantially rigid material, such as plastic,
metal, wood or other synthetics. As an alternative to the
shallow CllpS described, the portable flights 10 ma~ take the
~ h~
form of simple semicircular plates, rlvetted or otherwise
secured to a series of rungs of coil spring 2.
In the present embodiment, as shown in FIG. 3,
the portable flights 10 are located on alternate rungs along
the length of the coil spring 2. It will be understood, however,
that the distribution along the length of the coil can be in
any desired sequence, such as one in every one, two, three,
four, five or more rungs. Although preferred, the sequence
need not be regular or periodic.
Further, in accordance with a preferred arrangement,
the orientation of the portable flights 10 is varied in a
regular sequence from one to the next, along the length of
coil spring 2, in the manner shown in FIG. 3. For example,
if the first in the series is disposed with reference point P
in a given position, the next portable flight above it is
disposed with reference point P ~otated 120 in a clockwise
direction in a plane substantially normal to the principal
axis of the coil; the next in the series is disposed with
point P rotated 240 clockwise; and the next is disposed ~ith
point P returned to the initial position. Thereafter, the
series is repeated along the length of coil spring 2. It
will be apparent that the angular relationship between
successive members of the series can be varied in any desired
way, so that there may be ~s few as two portable flights, or as
many as five or more portable flights, to each repetitive
series along the length of the coil. On the other hand, the
angular orientation of the portable flights may be completely
random.
Referring again to ~IG. 1 of the drawingc;, there is
shown another novel feature of the present inven~ion. The
tubular exhaust chute 7 is disposed to deposit transported
granular or pul~erized material in a pile 12 which may be
collected, for example, in a container 9. In order to reduce
the personnel re~uired to monitor operation of the system to
prevent spillover of the material collected in container 9
a microswitch 15, disposed to be operated by a toggle
mechanism 14, is suspended by a bracket from the frame
of the conveyor, or otherwise supported above the site where
the pile of material 12 is deposited by the exhaust chute 7.
A flexible lever arm 14a, which comprises a flexible rod
several inches to a foot or so in length~ is connected to
depend from conventional toggle switch 14. The latter supports
at its lower end an angularly bent paddle 18 which is adjusted
by setscrew means 14c so that the bottom surface of paddle 18
is substantially tangential to a desired maximum horizontal
reference level of the pile 12 in container 9. When the pile
12 accumulates above the reference level, the arm 14a is
deflected so as to move the conventional toggle switch 14,
which is mechanically coupled to open-circuit conventional
microswitch 15. The latter is connected in series with one
terminal of a conventional source of either alternating-current
or direct-current power 19, which is connected to drive the
motor 4 to rotate its shaft 4a. (See Fig. 2).
FIGS. 5A and 5B are detailed showings of the micro-
switch-toggle switch paddle assembly. In the present
illustrative embodiment, the paddle 13 is formed of any
rigid material, preferably a sheet o~ metal, such as stainless
steel, say, 0.035" thick. The rectangular connecting portion
18a is 2" along the edge by 3" wide; and the outwardly extending
tongue 18b is bent at an internal angle of~ say, 135 to the
principal plane of 13a, extending outwardly about ~", and
being tapered outwardly to a width of about 321" at the
external end. The supporting block 14b, which is 21" b~ 1" by
1", may also be of steel or the like, and is welded or
otherwise secured in centered relation to the rear face of 18a.
A central bore in supporting block 14b, which is substantially
vertical in unoperated position o~ paddle 18, accommodates
the flexible lever 14a in slidable relation, so that the
position of 14b can be adjusted along the length of 14a by a
setscrew 14c.
Referring again to Fig. 1~ when the pile 12
accumulates above the reference level R, the bottom o
paddle 18 is contacted and pushed up, deflecting the lever arm
14a of toggle switch 14 so that the microswitch 15 is tripped,
cutting off power from the source 19 to the motor 4. This
stops the conveyor. When the height of pile 12 is reduced
below the reference level, the toggle switch is released,
again closing the microswitch 15, causing the motor to again
operate the conveyor mechanism.
An alternative to the paddle 18, namely, deflectable
ring 20, is shown in FIGS. 6A and 6B of the drawings.
In the alternative embodiment about to be described,
the output or collection container 9 of FIG. 1 is replaced
by a round barrel-like container 9', as shown in FIG. 6A. A
metal ring 20 of stainless steel or the like, having an outer
diameter of, say, 12" and an inner diameter of, say, 112",
being 14" round in cross-section, is disposed in a horizontal
plane around the inner periphery of the barrel 9' so as to
be substantially contiguous with the inner walls thereof,
but having su~icient clearance ~rom the walls -to prevent
sticking. The deflector ring 20 is disposed at the reerence
level R to respond to the desired maximum height ~or the
material pile 12'.
-- 11 --
Disposed diametricall~ across from each other in
container 9' are a pair of L-shaped rods 22 and 23, which
may also be of stainless steel, ~" round in cross-section,
having their external ends welded or otherwise secured at
diametrically opposite positions to the inner periphery of
ring 20. Arms 22 and 23 extend inwardly for about 5t~ on each
side to form a pair of elbow bends, providing parallel,
vertical legs 22a and 23a, spaced apart about 121" and each
extending upwardly about, say, 2 feet. The upper ends of
legs 22a and 23a are respectively threaded through a pair of
parallel bores which are symetrically spaced on opposite
sides of the central bore in a rectangular block 27, in
which the fle~ible toggle switch lever 14a rides and is
secured by setscrew 14c, as in the embodiment of FIGS. 5A and 5B.
The block 27 may be, for example, of stainless steel 12" thick,
1" wide and 2" long. The legs 22a and 23a move slidably in
their respective parallel bores, and are respec~ively each
secured in a desired position by setscrews 28a and 29a.
It will be apparent that in this embodiment,
deflecting ring 20 has the advantage of responding to material
in the pile 12, rising above the reference level R, regardless of
where it accumulates in a horizontal plane.
It will be understood that the present invention
is not limited to the specific embodiments or elements
thereof which have been described herein by way of illustration,
but only by the scope of the appended claims.
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