Note: Descriptions are shown in the official language in which they were submitted.
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Specification
A field of invention
The invention relates to screening machines for screening gravel, soil, wood
chips,
rubber, mining materials and the like. This invention has a screen deck
vibrating
mechanism that has a simple and effective design.
Background/Specification
Existing road- portable, stationary or machine attached commercial material
screening equipment is expensive and one stationary model, in particular, does
not provide for "overs" or their action is more sifting than aggressive
separation.
This invention provides for aggressive separation with impressive production
at a
lower cost. Maintenance and repair with most existing units is expensive or
requires specialized parts. This unit is easy and inexpensive to repair and is
designed to be efficient, versatile, cost-effective and meet a need in the
market
place for less expensive, efficient, smaller scale screening applications.
This invention could also be used for larger scale operations, heavy industry,
using
appropriately sized moving parts.
It is common for most screening machines to be quite large and expensive to
manufacture and maintain. This makes it costly for the small contractor to buy
or
rent.
In one screener sifter in US Pat. Application publication # US 2005/0274654 A1
there is no provision for the oversized material to move away from the screen
deck
once the material is screened.
In a rotating drum style screener as the Trommex brand at
www.screeningandcrushing.com that is attached to a skid steer or excavator,
the
drum loading is very awkward because it has a round loading mouth. The main
bearing used in these machines is very expensive and costly to replace if worn
out.
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Most larger screening units use expensive eccentric shafts, counterweights,
gear drives, bearings, springs, hydraulic components and diesel engines to
drive
the unit because they must vibrate a heavy frame box with screens mounted
inside.
Some smaller units shake one end of the screen deck up and down but not
efficiently as in Hudson brand at www.hudson.com and some Proscreen models
at www.omhproscreen.com.
The Reed screeners US Pat. # 4,197,194 have two screen decks but these
machines discharge their overs and midsized product from each screen deck onto
one pile.
This is inefficient because if the customer wants three products he has to
change
and remove a screen and run the overs material through the screener again to
get
three product.
Truck screeners US Pat. # 5273164 have to dump their load somewhere every few
loader bucket loads.
I have found that these disadvantages can be overcome by my invention.
The invention is an assembly consisting of a cam shaft driven screen deck
supported on angled legs, driven at high R.P.M. at a travelling distance of
approximately 3/8 of an inch. The diagonal reciprocating and vibrating motion
produced by this assembly results in a highly efficient screening machine
rivaling
anything in the market particularly in the small to medium business niche and
for
those who cannot afford expensive rental machines or large machine purchases.
The added benefit of this invention is the environmentally friendly lack of
need for
hydraulic components, its efficient use of energy, low maintenance and the
reasonably priced and easily replaceable, unspecialized, parts.
The unique feature of this invention is that it applies simple forces of
physics and
mechanical actions, direct drive, that result in a reciprocating, vibrating
and forceful
diagonal motion unlike the inefficient sifting motion of oscillating machines
and
solves the problem of removal of overs and multi-product production. It is in
a
separate category from less effective sifters and from the larger more
expensive
machines and is in a niche of its own. It is also has multiple uses and is
easily
adjustable and would meet the needs of a number of businesses.
An objective of this invention is to provide a portable screener, with a
stationary
option, that is easy to maintain.
Another objective is to provide an apparatus that uses as few moving parts as
possible, ie. direct drive, and an effective mechanical action to result in
low
manufacturing cost.
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A further objective is to provide an invention that has inexpensive, readily
available
maintenance parts that are not specialized.
Another objective is to not use hydraulic components in the stationary machine
thus lowering costs and making it better for the environment.
Another objective is to provide ease of adjustment through the link arm
adjuster
and leg adjustments.
My invention would be useful for many small contractors, farmers, miners,
ranchers, manufacturing or material sorting plants because it is affordable,
effective and easy to maintain. This invention can be used in several
different
styles of screening machine configurations using the same screen deck
mechanism, for example, as an attachment to a loader or excavator as shown in
drawings Fig.10, Fig.11 and Fig.12.
The focus of this invention is a reciprocating screen deck assembly that is
set on
angled support legs moveably mounted within a framework and driven by a single
force adjustable link arm that is connected to a cam drive shaft. The RPM,
angle
of the legs and cam throw are adjustable. The support legs are at an angle
relative
to the screen deck when at rest and while working. The angle of the legs on
the
non-drive end are independently adjustable. When driven back and forth
diagonally with a cam drive shaft at the correct speed and distance this
results in a
very effective and aggressive screening action.
The screen deck itself vibrates, not a heavy box frame as in most other
screening
machines, thus requiring less energy to operate.
In this stationary unit a simple electric generator or a household source
would
provide enough electricity to power the electric motor drives. This would
reduce
operating costs.
In addition to the effectiveness of the screen deck it is also inexpensive to
manufacture and simple to maintain, making it a desirable option to what is
presently in the market place.
To illustrate the effectiveness of this screening apparatus the test specs.
were
done with the deck in a horizontal position. Most screen decks rely on a mid
to
steep angle to help move the material down the length of the screen deck but
this
deck does not. The production measured on my prototype was on a 17" wide by
40"long by 3/4" square mesh screen cloth was .44 cubic yards per minute. The
material used was standard gravel material and separated into 2 products.
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This invention as shown in Figure 1 represents a rock, or similar product,
material
separation machine. The core of this invention lies in five key aspects:
= First is the angle of the hinged support legs, while at rest and working,
in
relation to the screen deck. The resulting action when driven at the
correct speed allows for material to be separated with relative ease while
throwing overs off the end of the deck. The non-drive end legs are
independently adjustable.
= Second is the aspect of the single force eccentric cam as shown in figure
2 (17) connected to a single force adjustable link arm. This results in a
precise throw that allows for optimal material separation.
= Third is a properly weighted flywheel to dampen vibrations in the
screening system, if necessary.
= Fourth is the angle of the screen deck as shown in figure 3, which allows
for larger volumes of material to be separated.
= Finally the industrial environment that the invention will be subjected
to
would be reflected in the materials used to build the device, for example, a
large-scale industry or a machine attachment.
The combination of these five factors, as well as the others previously
mentioned,
are what makes this invention unique and a new design for effective material
separation.
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Brief description of drawings
Figure 1 is a perspective view of 4 screen frames driven by the cam drive
shaft assembly
Fig. 2 is a close up perspective view of a single adjustable link arm with
a
keyed eccentric cam placed in the large end
Fig. 3 is a perspective side view of a single screen frame and angled
support legs
Fig. 4 is a side view of 2 screen frames and angled support legs being
driven by an electric motor drive assembly
Fig. 5 is a close up perspective view of the drive assembly shown in Fig.
1
showing the bearing mounted keyed cam drive shaft, eccentric cam
and link arm
Fig. 6 is a perspective view of various sizes of screen cloth installed in
the
screen frames
Fig. 7 is a front perspective view of a portable screening apparatus
embodying this invention. The screen cloth is not shown for clarity.
Fig. 8 is a perspective view from the hitch end showing the screening
apparatus of Fig. 1 after it has screened the rough material into 3
piles. Fines, underneath the machine, oversized material, left pile,
and middle product, under far end of conveyor
Fig. 9 is a back perspective view, loading side, showing drive arrangement
and various material piles noted in Fig. 8. Material retaining walls and
screen cloths are not shown for clarity
Fig. 10 is a drawing of a machine portable attachment using the same
screening mechanism described in the abstract. The left view shows
the drive end with the position of the screen deck with the drive
mechanism not shown. Connecting plate is shown where the
apparatus would connect to a loader. Right view is a cutaway front
view showing the material being screened.
Fig. 11 shows the machine portable attachment digging into an unscreened
pile to fill the hopper
Fig. 12 shows an upright view of apparatus attached to a loader
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Drawings which illustrate the embodiments of the invention.
The screener machine drawing Fig. 8 shows the material that has been separated
into the various sizes predetermined by the screen mesh sizes chosen.
A The larger, oversized, material vibrates over the top surface of the
deck and
falls off the end onto a pile (24).
B The material that drops through the top screen deck falls onto the next
screen
deck and vibrates to the end onto a sideways mounted conveyor
moves up the conveyor and drops onto another pile (25). This material we will
call the mid sized product.
C The fines material that is small enough to drop through both the screen
decks
will fall onto the ground below onto a third pile (26).
The operator of the bucket loader would remove the material from these three
piles when necessary.
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Summary/ Detailed Description
In one aspect of the invention, a portable material screening machine
comprises of a
basically rectangular frame. The screen decks slope gently downward at the
discharge end. The top end has angled metal funneling surfaces to direct the
material onto the vibrating screen deck surfaces. Rubber dampering blankets
may
be attached part way down the top deck to slow the flow of material as it
travels
along the deck toward the discharge end. This prevents rocks bouncing over the
deck surface.
In one embodiment of this invention, shown in Fig. 9 in the drawings it shows
four
separate screen decks (two sets) that are cam driven by the same cam drive
shaft.
A sideways conveyor collects and moves middle sized product up the conveyor to
a
pile. This embodiment would be capable of making three different products.
One aspect of this embodiment shows a moveable set of wheels Fig. 7 , for
transport, (7) at the back end of the screening machine.
Another aspect of this embodiment shows a towing hitch for use when moving the
screening machine form site to site. Fig. 7 (6)
A different but more basic embodiment would have a similar rectangular
framework,
moveable wheels and tow hitch with two screen decks side by side with no
sideways
conveyer. The material funneling surfaces would be approximately the same as
stated in the first embodiment. This screening machine would be capable of
screening two different products.
Shown in Fig. 7 the screening machine has a rectangular box type frame.
The machine has a higher back and sides where the material is dumped onto the
screen deck and a slightly lower front side, discharge of material side. The
funnel
shaped sides Fig. 7 (2,3) direct the material onto the top screen deck
surface.
In Fig. 4 the top screen decks, larger mesh, (8A) which separates coarse
material is
set above the lower screen decks, finer mesh, (86). In Fig. 8 the side ways
conveyor (1) is situated to collect and convey middle sized material that has
gone
over the end of lower deck to a stock pile.
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In Fig. 9 the screen decks are situated in frame (4) on angled support legs
(9) .
They are slightly narrower than frame (4) to allow back and forth movement
when
driven by drive assembly.
In Fig. 1 showing 4 screen decks, the cam drive shaft (13) are driven by an
electric
motor (16), pulley arrangement (15) at approximately 700 to 1100 RPM. This
drive
arrangement is bolted securely to the frame Fig. 5. The eccentric cam part
Fig. 5
(17) is keyed to the cam drive shaft (13) .
In one 360 degree turn the cam moves the 4 link arms Fig. 5 (12) back and
forth
approximately 3/16 inches to 1/2 inches depending on the eccentric cam the
operator has installed on the drive shaft. 3/8 inch throw is standard.
These cams (17) are changeable.
In Fig. 2 the link arm (12) at one end has a nylatron bushing pressed into it
(18),
width is slightly less than the eccentric cam. At the other end it is pinned
(19) to the
screen deck. Midway on this link arm is an adjustment nut (27). This adjuster
allows
the operator to vary the angle of the angled support legs in relation to the
screen
deck.
In Fig 4 this adjustment would vary the aggressiveness of the screen deck
vibration.
In Fig.4 the 2 screen decks on one side of the machine oppose each other 180
degrees in one 360 degree revolution of the drive shaft.
This results in less energy being used to rotate this mechanism because as one
screen deck is moving up and forward (diagonally) the other would be moving
back
and down,diagonally, providing dual use of the energy stroke. See directional
arrows
(C) in Fig. 4.
In Fig. 4 the screen decks (8A),(813) are mounted on 4 or more angled support
legs
each one with an end pinned to the screen deck and the other end pinned to the
frame. The angle of the support legs to the screen deck is critical. It should
be
approximately 58 degrees. This is achieved by the length of the link arm Fig.
2.
In Fig. 1 the screen deck frames are constructed of metal or suitable
material.
The screen cloth is removable and designed to be clamped securely into the
screen
frame.
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In Fig. 9 the side ways conveyor would also be powered by and electric motor
and
reducer (16A) to rotate the belt fast enough to carry the middle sized
material away.
This conveyor is mounted at a slight incline to allow for the loader person to
remove
the pile when needed and to provide space for a higher stockpile.
In one aspect of this embodiment the high side is open on the back of the
machine
see Fig. 9. This rectangular opening between 5A,5B,5C would be approximately 6
feet high and 8 feet wide to allow for ease of movement for the loader
operator to
retrieve the fines material that has dropped through both screens to the
ground
below. This rectangular box like area would have metal walls on the front side
and
side walls to keep all the 3 product sizes separate from each other, not shown
for
clarity.
In Fig. 7 this embodiment has a set of wheels (7) fixed to one end at the
screening
machine. These wheels could be moveable up and down. In the up position the
frame of the screening machine would rest squarely on the ground. In the
transport
position the wheels would be lowered and the machine would be raised slightly
off
the ground.
On the other end the machine would have a trailer hitch secured to it. This
would
have a jack for raising and lowering this end of the machine to allow for
setting the
machine on the ground for the screening position or raising it up and setting
it on the
truck towing hitch for the travel position.
The hitch area would also serve as a place to mount the generator needed for
powering the electric motors.
In this embodiment illustrated in Figures 7, 8 and 9 if the operator was
making only 2
products they could blank off the lower screen decks thus sending the fines
material
onto the conveyor and stock piling it instead of it falling to the ground
below.
In another embodiment using the same off set cam drive arrangement and the
same
basic rectangular box type frame there would be one level of screen deck
instead of 2 levels as in the previous embodiment. The overs would travel off
the end
of the screen deck and fall onto the ground. The fines would fall through the
screen
opening to the ground below. There would be only 2 products made with this
arrangement. There would be no side ways conveyor installed on this simple
model.
As stated in my Abstract the focus of this invention is a reciprocating screen
deck
that is supported on angled legs relative to the screen deck. This screen deck
system can be placed in a number of screening machine embodiments and in
another embodiment there could be a second conveyor under the screen deck
catching the fines. This second conveyor could be situated between the
transport
wheels.
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It is understood that the above-described embodiment is merely illustrative of
the
application. It will be appreciated by those skilled in the arts pertaining
thereto, that
the present invention can be practiced in various alternate forms, proportion,
and
configurations and while the invention has been shown and described with
reference
to a preferred embodiment or embodiments thereof, it will be understood by
those
skilled in the art that various changes in form and detail may be made therein
without
departing from the spirit and scope of the invention as defined by the
appended
claims.
