Note: Descriptions are shown in the official language in which they were submitted.
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B~CI~GROUNI:) OF TIIE INVENTION
Field of the Inven-tion
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This invention relates in general -to conveyors and in parti-
cular to endless chain-type conveyors for the movement of bulk goods.
Descri tion of the Prior Art
P._ ~
It is highly desirable in the conveying of bulk goods and
bulk crops, in particular, that the conveyor have positive traction;
that the load bearing surface of the conveyor be flexible to minimize
damage to the crops; and that the conveyor drive system remain free
from obstruction. U.S. Patent No. 2,717,703 issued to W. Kull dis-
closes a feeder conveyor which may be of the rope, belt, or chain
type and which utilizes drums, sprockets, or wheels for guiding and
driving the endless belt. Rull further suggests use of flexible
material such as textile fabric for use in the construction of arti-
culating flap members. I~ull does not suggest the manner in which the
flaps might be combined with the chains when -the positive traction
of the chains is preferred.
U.S. Patent No. 2,496,463 issued to R.C. Gaddis discloses a
conveyor using chains and sprockets for positive traction and further
discloses a series of transverse bars welded or otherwise secured to
laterally spaced chains for moving material along a lower spaced
longitudinal floor.
U.S. Patent No. 4,055,265 issued to L.J. Eisenman discloses a
series of transverse bars secured between laterally spaced chains
and a series of overlapping flexible flaps attached to the bars for
supporting material placed thereon. In the Eisenman invention the
overlying load causes the flaps to pull directly against the trans-
verse bars to which they are attached resulting in the flap tearing
away from the attaching rivets.
Current problems in the art, to which the present inven-tion is
addressed and which are not solved by the prior art include the
"down-time" caused by damage to the rigid cross bars, and to the
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chains to which the rigid cross bars are fixed by obs-tructive
materials such as rocks and stones which aLe inadvertently included
with the bulk materials; the "down-time" caused by the teariny of
flaps; the prevention of "build~up" material on the conveyor floor;
the low dispensing rate of fine grains because of the rolling action
of overlying grains relative to the conveyor belt; and the down-time
due to lost flaps.
SUMMARY OF THE INVENTION
The present invention comprises, generally, a conveyor having
a longitudinally extending floor and divergently upstanding walls
supported on suitable framework; two or more sprocket driven chains
defining an upper flight and a lower return flight relative to the
floor and a plurality of flexible flap members separately fixed to
each chain, each of said flap members including a flexible scraper
adapted to ride upon and engage the top surface of the floor, under
load, for scraping the floor of debris. A more precise definition
of the invention may be found in the appended claims.
It is therefore an object of the present invention to provide
an endless chain-type conveyor having flexible flaps provided with
flexible scrapers for cleaning the floor surface of the conveyor.
More specifically it is an object of the present invention to
provide scrapers which are fastened to flexible flaps forward of
the flaps attachment to conveyor chains to that the flaps are pushed
forwardly.
It is also an object of the present invention to provide a
conveyor in which endless chains are independently connected to
flexible load-bearing flaps to prevent conveyor damage due to obstruc-
tive material.
It is a further object of the present invention to provide a
conveyor having flexible load-bearing flaps providing pockets for
movement of fine particles.
s~
Additional objects and advantacJes will become apparent and a
more -thorough and comprehensive unders~anding may be had Erom
the following descrip~ion talcen in conjunction with the accompanying
drawings forming a part of tllis specifica-tion.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a conveyor made according to
the present invention.
Fig. 2 is a close-up perspective view showing details of
construction.
~ig. 3 is a sectional view taken along lines 3~-3 of Fig. 2.
Fig. 4 is a fragmentary side view showing chain engagement
with a sprocket wheel.
Fig. 5 is a fragmentary view of the under surfa~e of the
flexible flaps and chains of the invention.
Fig. 6 is a fragmentary plan view of the flaps showing under-
lying attachment bars and flexible scrapers in outline.
DETAILED DESCRIPTION OF THF. INVENTIO~J
Referring now to the drawings a~d to Fig. 1 and 2, in
particular, one embodiment of the conveyor of the present invention
is shown to advanta~e. Conveyor 10 includes framework 5 supporting
a floor 7 and side walls 8; a pair of endless chains 20 driven by
sprocket wheels 30; a second set of sprocket wheels 40 serving as
idlers; flexible load-bearing flaps 50; and drive means 60.
Framework 5 may be any suitable framework for supporting the
conveyor and may be either fixed or portable. A vehicle chassis
may readily serve as the framework.
A longitudinal, horizontally extending, floor 7 having a sub-
stantially planar upper surface is mounted on the framework. A
pair of side walls 8 jo7n the floor adjacent its lateral edges.
Walls 8 preferably extend upward and divergently outward for funneling
overlying material to the conveyor. Additional structural provisions
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such as a storage bln, end walls, end gates, and the like may of
course be added but are not a par-t of the present invention.
Endless chains are provided to give positlve traction to
the conveyor, as opposed to endless belts which are prone to slip.
While any number of such chains may be provided, depending upon
the width of the conveyor, a pair of laterally spaced chains 20,
as shown in the figures, will generally be preferred. The upper
flight of each chain rests upon and moves along the upper surface of
floor 7 and the lower flight is carried along below the floor and
may be supported by longitudinally spaced U-shaped support trusses
6 as shown in Fig. 4. Such trusses are particularly useful ~or
chains of long length to prevent excessive weight on the supporting
sprocket wheelsO Trusses 6 are also useful for dislodging conveyed
material which might otherwise stick to the f~aps carried by the
chains. Each chain is engaged at one end of the floor by a drive
sprocket wheel 30 which may be carried upon a common shaft and is
engaged at the other end of the floor by idler means 40 in the form
of a sprocket wheel. While the idler means is preferably in the
form of a sprocket wheel, it will be understood that rollers, friction
guides, and the like may also serve as idlers. Each structure is
old in the art and a lengthy description is believed unnecessary.
A motor 60, engine, or like power source, drive sprockets 30 for
moving conveyor chains 20.
Of prime importance in the present invention is the flexible
load bearing flaps and their attachment to the chains. Flaps 50
may be constructed of any suitable jfabric, plastic, or rubber, or
any combination thereof. Preferably the flaps are made of rubber-
fiber composition which permits the flap to generally conform to
the shape of the load and the flap supports underlying structures.
The flaps are substantially rectangular in form defining a leading
edge and a trailing edge. The leading edge may be clipped or beveled
backwardly at an angle of approximately 45, as shown to advantage
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t~
in Fig. 2, to reduce fric-tion between the edges oE the flap and
sides ~. The leading edge is provided wi-th a downwardLy dependiny
flexible scraper 55, having a thickness substantially equal to the
endless chains to which each flap is attached. Scraper 55 extends
the substantial width of the leading edge, having appropriate notches
52 for the chain, as is shown to advantage in Figs. 2 and 3. The
scraper may be constructed of any suitable flexible material. Rubber
has been found to work extremely well. The scraper may be attached
to the under surface of each flap by vulcanization or other suitable
fastening means. It is to be noted that the scraper is mounted for-
wardly of attachment bar 25 so that the bar pushes against the
scraper and therefore pushes the flap to which the scraper is attached.
Each chain is independently attached to each flap adjacent the
leading edge of the flap by means of at least one attachment bar 25.
In this manner, it is to be noted, only flexible flap 50 and flexible
scraper 55 extend between respective laterally spaced bars 25. The
resiliency of members 50 and 55 permit individual chains and attached
flaps to ride over minor obstructions such as rocks or stones which
may work their way under the flap, scraper, or chains.
2Q Attachment bars 25 preferably include two flat laterally pro-
jecting members which are welded to each side of a chain link. The
bars include vertical apertures adapted to receive either bolts or
rivets 22 for attachment of flaps 50. The flaps are attached to the
chains in such a manner that the trailing edge of each flap overlaps
a leading edge of a rearwardly located adjacent flap to present a
continuous belt-like surface.
The operation of the conveyor will now be described using the
unloading of fine grain, such as oats, from a truck, for example.
It is assumed that the conveyor is suitably attached to the under
surface of the truck bin 9, as illustrated in Fig. 1. Motor 60 is
activated to drive sprocket wheels 30 for pulling chains 20, in their
engagement with floor 7 and idler sprockets 40, to the rear of the
q~
conveyor. Flexible flaps 50, under the weight of the yraln, conform
to the shape of the unclerlying structure--the floor 7, the chains
20, attachment bars 25, and scrapers 55---to form "pockets" in each
flap. These moving pockets tend to prevent slippage between grain
particles for improved eficiency of emptying of the bin. The
weight of the grain also tends to seal the sides of flaps ~0 against
side walls ~ to prevent accumulation of grain below the flaps. Be-
cause of their greater density, rocks or stones which have been
mixed with the grain during harvesting, tend to work to the bottom
of the conveyor and will occasionally work under the flaps together
with small amounts of grain. Any such debris is swept rearwardly
by scraper 55 of each flap until ejected at the end of the conveyor.
It is to be particularly noted that rocks which may become lodged
in or under chain links may cause the chain to rise above the plane
of the floor upon which it rides. In that each chain is independent
relative to a laterally spaced chain, for the reason that the chains
are connected laterally only by flexible flaps and scrapers, the
conveyor continues to function.
As each flap reaches the end of the conveyor, the trailing
edge of the flap slips on the leading edge of the adjacent successive
rearward flap thereby accommodating for the increased pitch diameter
of the sprockets. The trailing edge of the flap is then flipped
outwardly, tending to free the flap of attached grain particles.
Any grain which may adhere to the flap is likely to be discharged
as the flap engages spaced trusses 6 on its return flight.
Having thus described in detail a preferred embodiment of the
present invention, it is to be appreciated and will be apparent to
those skilled in the art that many physical changes could be made in
the apparatus without altering the inventive concepts and principles
embodied therein. The present embodiments are therefore to be consi-
dered in all respects as illustrative and not restrictive, the scope of
the invention being indicated by the appended claims rather than by
the foregoing description, and all changes which come within the
meaning and range of equivalency of the claims are therefore to be
embraced therein.
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