Note: Descriptions are shown in the official language in which they were submitted.
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PORTABLE CRUSHING AND SCREENING PLANT
Technical FieLd
This invention relates to a vehicle-mounted
closed circuit portable crushing and screening plant in
which a plurality of units for processing material to be
crushed and screened, such as a grizzly, a primary
crusher, a secondary crusher, and a screening device are
mounted on the vehicle, with the grizzly and the primary
and secondary crushers discharging their outputs onto a
1û conveyor system mounted on the vehicle and which delivers
the material to the screening device for recirculation
and/or for discharge as end product or products. The
portable crushing and screening plant of the invention has
particular utility for processing gravel or stone for
commercial use, including sizing and sorting the gravel or
stone, but may also be used for crushing and screening
other material such as mineral ore including iron ore or
the like.
BACKGROUND OF THE PRIOR ART
It has been known in the prior art to provide a
portable crushing and screening plant in which a plurality
of devices for processing material to be crushed are posi-
tioned in overlying and discharging relation to a firstconveyor, which first conveyor then discharges the
material ~hich has been deposited upon it onto a second
conveyor which elevates the material being processed and
deposits such material through the intermediary of still
another conveyor into the upper feed end of an inclined
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vibrating screen;ng device wh;ch class;f;es the mater;al
thus deposited on the vibrating screening device for
rec;rculation and/or for discharge from the screen;ng
device as one or more end products of predetermined size.
Such an arrangement ;s shown, for example, by U.S. patent
2,593,353 issued to Harry J. Shelton, Jr. on April 15,
1952.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to
provide a portable closed circuit crushing and screening
plant for mounting on a vehicle and including an apparatus
for processing a material ~hich is being crushed, and
further including a dual belt conveyor-elevator including
a normally horizontal feeder portion ~hich receives the
output product of the apparatus and an elevator portion
which receives material from the horizontal feeder portion
and which elevates the material to the inlet end of a
screening device ~hich classifies the material either for
purposes of recirculation to the aforesaid apparatus or
for discharge to at least one end product discharge outlet
of the screening device.
It is another object of the invention to provide
a portable crushing and screen;ng plant adapted to be
mounted on a vehicle both for transport and also ~hile the
crushing plant is in operation, and particularly useful
for processing gravel or stone or the like but ~hich may
also be used for processing other material such as mineral
ore, the portable crushing and screening plant including a
processing apparatus for processing material ~hich is
being crushed, the portable crushing and screening plant
additionally including a vibrating screening device and a
dual belt conveyor-elevator ~hich delivers the output
product of the aforesaid processing apparatus to the input
end of the screening device, uith the screening device and
the conveyor-elevator both being structurally arranged to
be moved from an extended "in use" position to a retracted
transport position.
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It is another object of the present invention to
provide a portable closed circuit crushing and screening
plant for mounting on a veh;cle and ;nclud;ng a plural;ty
of dev;ces for processing the material wh;ch is be;ng
crushed, such as a gr;zzly, a primary crusher and a
secondary crusher, and further including a dual belt
conveyor-elevator includ;ng a normally hor;zontal feeder
port;on wh;ch receives the output product of the gr;zzly
and of the pr;mary and secondary crushers, and an elevator
1û port;on wh;ch rece;ves mater;al from the hor;zontal feeder
portion and which elevates the material to the inlet end
of an ;ncl;ned screen;ng dev;ce wh;ch class;f;es the
mater;al e;ther for purposes of rec;rculat;on or for
discharge to at least one end product discharge outlet of
the screen;ng dev;ce.
It is a further object of the invention to pro-
vide a portable crushing and screen;ng plant adapted to be
mounted on a vehicle both for transport and also while the
crush;ng plant ;s in operation, and particularly useful
for processing gravel or stone or the like but ~h;ch may
also be used for processing other material such as m;neral
ores, the portable crush;ng and screening plant includ;ng
a group of mater;al process;ng devices such as a gr;zzly,
a pr;mary crusher and a secondary crusher, all of wh;ch
have a relat;vely fixed structural pos;t;on on the
portable crush;ng and screen;ng plant, w;th the portable
crush;ng and screen;ng plant add;t;onally ;nclud;ng an
incl;ned v;brat;ng screen;ng device and a dual belt
conveyor-elevator wh;ch delivers the output product of the
30 gr;zzly and of the pr;mary and secondary crushers to the
;nput end of the screen;ng dev;ce, w;th the screening
dev;ce and the conveyor-elevator both be;ng structurally
arranged to be moved from an extended ";n use" position to
a retracted transport position.
In ach;evement of these object;ves, there ;s
provided in accordance w;th the invention a closed circuit
portable crushing and screening plant adapted to be
mounted on a veh;cle, sa;d portable plant comprising an
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apparatus for processing raw material to be crushed, said
apparatus including an outlet through which a product of
said processing is discharged, a screening device, a dual
belt conveyor-elevator including a substantially hori-
zontal feeder portion and an elevator portion, saidhorizontal feeder portion being positioned to receive said
product of said processing which is discharged by said
apparatus, said horizontal feeder portion being adapted to
deliver material deposited thereon to said elevator por-
tion, said elevator portion being adapted to elevatematerial received from said horizontal feeder portion and
to discharge the material thus elevated onto said screen-
ing device, said screening device being adapted to
classify the material deposited thereon into a first
component which is recirculated to said apparatus for
further processing and into at least one additional
component which is discharged from said screening device
as an end product.
Further objects and advantages of the invention
will become apparent from the following description taken
in conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWIN~S
Fig. 1 is a top plan view of the portable
crushing and screening plant of the invention with the
plant being shown in operating position;
Fig. 2 is a side elevation view of the portable
crush;ng and screen;ng plant of Fig. 1;
Fig. 3 is a section view of the portable crush-
ing and screening plant taken along line III-III of Fig.
2;
Fig. 4 is a side elevation view of the portable
crushing and screening plant of the invention in transport
position;
Fig. 5 is a rear end view of the portable
crushing and screening plant in transport position; and
Fig. 6 is a diagrammatic view of the portable
crushing and screening plant, showing the interrelation of
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the various components of the crushing and screening
plant.
DETAILED DESCRIPTION OF T E INVENTION
Referring now to the drawings and more parti-
cularly to Figs. 1-3, inclusive, which show the portable
crushing and screening plant in "in use" or operating
position, the portable crushing and screening plant is
generally indicated at 10, and includes a trailer 12
adapted to be towed by a tractor 14. In the "in-use" or
operative position of Figs. 1-3, inclusive, tractor 14 is
detached from trailer 12. Trailer 12 includes an
elongated frame or chassis 16 supported at the rearward
portion thereof by wheels 18 and at the forward portion
- thereof when in the operating position by a jack 20 which
is extended into ground-engaging position before tractor
14 is disconnected from trailer 12.
A vibrating grizzly generally indicated at 22,
and which may be of the well-known bar type grizzly, is
mounted on the rear portions of a pair of I-beams 17, 19
of chassis 16 and is provided with a vibrating mechanism
24 driven by a suitable power means. 5rizzly 22 serves as
a feeder for portable crushing and screening plant 10.
Grizzly 22 includes a grate 23 upon which the raw material
such as gravel, stone, or mineral ore, is placed. Pieces
of the raw material which are too large to be crushed by
primary crusher 34 tto be described) are retained on grate
23. The remaining portion of the raw material passes
through grate 23 into the hopper of grizzly 22 and the
grizzly separates such material into two components as
follows: (1) fines which are too small to be fed to the
primary crusher 34; and t2) "oversize" material which is
to be fed to primary crusher 34.
The rate of feed of material passing through
grizzly 22 may be controlled by controlling the frequency
of vibration of vibrating mechanism 24. Also~ the size of
the material passing through the grizzly to primary
crusher 34 may be controlled to some extent by adjustment
of the spacing of the grizzly bars.
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Grizzlys are per se weLl known in the prior art
and are shown, for exampLe, by United States patent number
2,321,166 issued to Loren G. Symons on June 8, 1943; by
United States patent number 2,831,270 issued to Walter J.
Hartwig on April 22, 1958; and by United States patent
number 3,106,523 issued to Rene' Courture on October 8,
1963.
The fines are discharged from grizzly 22 through
a discharge chute 26 onto the upper surface of the hori-
zontal run or feeder portion 100A of the outer belt
conveyor 100 of a dual belt conveyor-elevator 30 which
will be described more fully hereinafter. Grizzly 22
discharges the "oversize" component of the raw material
through a suitable chute 25 to the inlet of primary
gyratory crusher generally indicated at 34. Gyratory
crusher 34 is driven by a motor 36 through a belt drive
3~. Primary gyratory crusher 34 crushes the oversize
material delivered to it from grizzly 22 to a predeter-
mined size and discharges its output onto the upper
surface of horizontal feeder portion 100A of outer belt
conveyor 100 of dual belt conveyor-elevator 30.
Portable crushing and screening plant 10 also
includes a secondary gyratory crusher 40 mounted on
trailer chassis 16 contiguous but forwardly of primary
crusher 34 relat;ve to the tractor end of the portable
plant. Secondary crusher 40 is adapted to receive and
crush materiaL of a smaller size than that crushed by
primary crusher 34. Secondary crusher 40 is suitably
driven by motor 43 through a belt drive 44.
Crushing and screening plant 10 also includes a
three-deck vibrating screen apparatus generally indicated
at 50 including a top screen deck 50A which is adapted to
discharge material retained thereon into the inlet or feed
end of secondary crusher 40 for recycling. Multiple deck
vibrating screen 5û is vibrated by vibrating mechanism 54
which is rotatably driven by motor 55. Vibrating screen
50 is pivotally connected to the vehicle chassis s~ructure
at pivot point 56 at the lower end of the discharge end
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of screen 50. To permit vibrat;ng screen 50 to be
pivotaLly moved about its pivotal connection 56 from the
substantially horizontal transport pos;tion shown in Figs.
4 and 5 to the inclined "in-use" position shown in Figs.
1-3, inclusive, a hydraulic ram generally indicated at 58
is provided hav;ng a hydraulic cyLinder 60 which is
pivotally connected at point 62 to chassis structure 16.
Ram 58 includes a piston rod 64 which is moved to the
extended position shown in Fig. 2 to raise screening
device 50 to the inclined operative position shown in Fig.
2. Detachable vertical support members 65 may be used to
aid in supporting screen 50 in up~ardly inclined operating
position of screen 50 shown in Fig. 2. Support members 65
may be detached and removed when screen 50 is in the
transport position shown in Fig. 4.
Secondary crusher 40 is provided ~ith an inlet
chute 45 ~hich is adapted to line up with the discharge
end of top screen deck 50A of vibrating screen 50 when
vibrating screen 50 is in the inclined operative position
shown in Fig. 2.
In addition to top screen deck 50A, vibrating
screen 50 also includes a second screen deck 50B having a
discharge end which communicates with and discharges into
the stationary side discharge chute 70 mounted on chassis
16. Vibrating screen 50 also has a third screen deck 50C
having a discharge end which communicates ~ith and
discharges into stationary side delivery chute 72.
A transfer conveyor generally ind;cated at 74 is
positioned in underlying relation to third screen deck
50C. Transfer conveyor 74 is suitably secured to the
understructure of the multiple deck vibrating screen
apparatus 50 and in effect is a component part of the
screen apparatus 50. Thus, transfer conveyor 74 moves
upwardly with screen 50 about pivot point 56 to the
inclined operating position shown in F;gs. 2 and 6, and
moves do~nwardly with screen 50 about pivot point 56 to
the substantially horizontal transport position of Fig. 4.
Transfer conveyor 74 has an upper run 74A
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adapted to receive the f;nes ~hich pass through the
openings of third screen deck 50C. Transfer conveyor 74
is trained around longitudinally spaced roller members 76
and 78 and is driven by a suitable independent motor means
in such a direction that when the portable plant is in
operative position as seen in Fig. 2 upper run 74A of
transfer conveyor 74 moves upwardly at an inclination in a
Left-to-r;ght direction ~ith respect to the view sho~n in
Fig. 2 to discharge the fines collected on upper run 74A
of the transfer conveyor into side discharge chute 80.
Side discharge chute 80 is a detachable removable member
which is positioned as shown in Fig. 2 during operation of
crushing and screening plant 10, but is removed ~hen the
plant is in the transport position shown in Fig. 4.
It can be seen from the section view of Fig. 3
that the three side discharge chutes 70, 72 and 80 e~tend
laterally of trailer chassis 16 at an inclination so as to
be able to discharge onto corresponding conveyor belts
(not shown) mounted on the ground, and which convey the
material deposited thereon to corresponding stockpiles.
Of course, the material discharged by the respective side
discharge chutes 70, 72 and 80 can be delivered to other
appropriate receiving devices such as trucks or the like.
The dual belt conveyor-elevator or "Loop Belt"
conveyor generally indicated at 30 ~hich receives the
outputs of grizzly 22, of primary crusher 34, and of
secondary crusher 40 and ~hich conveys and elevates these
outputs to the input end of vibrating screen 50 is
generally similar to the dual belt conveyors disclosed in
U.S. patent 3,805,946 issued to Earl W. Yateman et al on
April 23, 1974, and in U.S. patent 4,007,826 issued to
Scott L. Bro~n, Jr. et al on February 15, 1977. Dual belt
conveyor 30 includes an outer belt conveyor generally
indicated at 100 in the form of an endless loop ~hich
operates around pulleys 102, 104, 106, 110, 112, 114, and
116 to define the outer belt loop. The inner belt
conveyor generally indicated at 120 passes over pulleys
116, 117, 119, 121, 126, 128, and 122 to define the inner
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belt loop. Outer belt conveyor 100 is driven by pulley
106, which in turn is dr;ven by a suitable drive means
108. Inner belt conveyor 120 is driven by outer belt
conveyor 100 through friction bet~een outer belt conveyor
100 and inner belt conveyor 120.
Outer belt conveyor 100 includes a ~orking run
1ûOA with a long substantially horizontal "feeder" portion
which extends from a position just slightly upstream or to
the left, as viewed in Fig. 2, with respect to the dis-
charge outlet of discharge chute 26 of grizzly 22, where
the return run 100B of outer belt conveyor 100 passes
around pulley 114 as illustrated, the rear end of the
longitudinally extending portion of the working run 100A
is adjacent the wheels 18 supporting the rear end of the
elongated frame 16. The longitud;nally extending portion
of the working run 100A extends forward below the hori-
zontal frame 16 in general horizontal alignment with the
wheels 18. Material from grizzly 22 and crushers 34 and
40 is deposited onto the the upper surface of the sub-
stantially horizontal feeder run 100A. Outer beltconveyor 100 is driven in a clockwise direction relative
to the view in Fig. 2 whereby horizontal feeder portion
100A of outer belt conveyor 100 moves in a left-to-right
direction with respect to the vie~ of Fig. 2. Hor;zontal
feeder portion 100A of outer belt conveyor 100 is
supported for substantially its entire length by troughing
rollers 130. Horizontal feeder portion 100A while being
substantially horizontal need not be absolutely horizontal
but can be inclined at an angle of up to about 18 degrees,
as pointed out in the aforementioned United States patent
3,805,946 of Earl W. Yateman et al.
In order to compensate for belt stretch and to
maintain outer belt conveyor 100 under tension at all
times, pulley 114 is connected to an automatic tensioning
device diagrammatically indicated at 135 (Fig. 6~ which
applies a constant horizontal force to pulley 114.
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Inner belt conveyor 120 includes an upwardly
extending forward run 120A (Fig. 2) which extends between
pulleys 122 and 116.
Forward run 120A of inner belt conveyor 120
includes a short downwardly facing portion 120B which
together with horizontal upper run 100A of outer belt
conveyor 100 defines a bight through which material
deposited on upper run 100A of outer belt conveyor 10û
passes between outer and the inner conveyor belts 100 and
120, respectively, to be clamped thereby.
The greater part of the length of forward run
120A of inner belt conveyor 120 is supported by a series
of troughing rollers 125. Troughing rollers 125 are
troughed in such manner as to maintain the upwardly
extending portions of inner and outer belt conveyors 120
and 100 in sealing engagement at the edges of the respec-
tive belt conveyors to prevent escape of the sandwiched
material being conveyed between the upwardly moving
portions of the two belt conveyors.
In order to compensate for belt stretch and to
maintain inner belt conveyor 120 under tension at all
times, the return run 120B of inner belt conveyor 120 is
connected to an automatic tensioning device diagram-
matically indicated at 137 which applies a constant
tensioning force to inner belt conveyor 120.
The material being conveyed in the elevator
portion of dual belt conveyor-elevator 30 is sandwiched
between the facing surfaces of inner and outer belt
conveyors 1ûO and 120 between point A contiguous the bight
of the two belt conveyors as just explained to a discharge
point indicated at C contiguous the upper end of the two
belt conveyors where the conveyed mater;al is discharged
onto top screening deck 50A of vibrating screen device 50.
The facing surfaces of the upwardly-moving portions of the
outer conveyor belt 100 and of the inner conveyor belt 120
grip the material between the two conveyor belts and
convey the material upwardly from point A contiguous the
bight to discharge point C.
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In the operative and elevating position of the
duaL belt or "Loop Belt" conveyor 30 shown in Figs~ 1 and
2, dual belt conveyor 30 is supported in its upright
position by a two-part support structure generally
indicated at 140. Support structure 140 comprises a lower
~ertical support section 140A which is suitably attached
to trailer chassis 16 contiguous the forward end of
chassis 16, and an upper support section 140B which is
hinged at the lower end thereof to the upper end of lower
support section 140A about a transverse hinge or pivot
axis 142. At the upper end thereof, upper support portion
140~ has secured thereto a horizontal bracket-like portion
143 which supports the outermost pulley 102 about which
the outer end of outer belt conveyor 100 is trained. In
the operating position of dual belt conveyor-elevator 30
shown in the views of Figs. 1 and 2, the lower end of
upper support section 140~ rests on the upper end of lower
support section 140A, with the two support sections 140A
and 140B being in vertical alignment with each other to
define a column-like member which supports the elevator
portion of the dual belt conveyor-elevator 30 in its
extended and elevated operating position, as seen in the
views of Figs. 1 and 2.
Description of Operation
The operation of the portable crushing and
screening plant can perhaps best be seen in the schematic
diagram of Fis. 6. Raw material such as gravel, stone, or
mineral ore is dumped onto grate 23 of grizzly 22. Pieces
of the raw material which are too large to be crushed by
primary crusher 34 are retained on grate 23. The remain-
ing portion of the raw material passes through grate 23
into the hopper of grizzly 22 and the grizzly separates
the fines from the raw material and discharges the fines
through chute 26 onto the upper surface of horizontal
feeder portion 100A of outer belt conveyor 100. The
"oversize" component of the raw material is discharged by
grizzly 22 through discharge passage 25 into primary
gyratory crusher 34. Primary gyratory crusher 34 crushes
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the "oversize" which is fed to it from grizzly 22 to a
predetermined size and discharges the crushed material
onto the upper surface of horizontal feeder portion 100A
of outer belt conveyor 1nO at a location downstream of the
locat;on where fines from grizzly 22 are discharged onto
horizontal feeder portion 100A. Material thus deposited
by grizzly 22 and by primary gyratory crusher 34 onto
horizontal feeder portion 100A of outer belt crusher 1ûO
is carried by horizontal feeder portion 100A to the bight
1û portion defined between the forwardly extending runs of
outer and inner belt conveyors 100 and 120, respectively,
and the material received between these conveyors is
sandwiched between the upwardly extending runs of inner
and outer belt conveyors 100 and 120 which define the
elevat;ng portion of conveyor-elevator 30. The material
is elevated by the elevating portion of conveyor-elevator
30 to discharge point C where the material thus conveyed
is discharged onto top deck 50A of vibrating screen 50.
Material which is retained on upper deck 50A of
vibrating screen 50 is recirculated by discharging such
material from upper deck 50A into inlet chute 45 of
secondary crusher 40 which crushes such rec;rculated
material to a predetermined size and discharges it onto
the upper surface of horizontal feeder portion 100A of
outer belt conveyor 100 downstream of the discharge points
of grizzly 22 and of primary crusher 34. The material
discharged by secondary crusher 40 onto horizontal feeder
portion 100A joins the material discharged by grizzly 22
and by primary crusher 34 and is conveyed along with these
discharge products upwardly by the elevating portion of
conveyor-elevator 30 to again be discharged onto top deck
50A of vibrating screen 50 either for further recircula-
tion or alternatively for separation into end products by
vibrating screen 50~
The material which passes through top screen
deck 50A but is retained by second screen deck 50~ is
discharged at the lower end of screen deck 5ûB into
stationary discharge chute 70 as an end product and is
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discharged by side discharge chute 7û onto a ground-
mounted conveyor belt or the like (not shown). Typically,
material discharged through side discharge chute 7û might
be minus 7t8" plus 3/8". The material ~hich passes
through second screen deck 50B but is retained on third
screen deck 50C is discharged from the lower end of third
screen deck 50C and passes as an end product into side
discharge chute 72, and may be received by another ground-
mounted conveyor belt or the like (not shown). Typically
such end product might be minus 3/4" plus 1/4". Material
which passes through third screen deck 50C and is received
on the upper run of transfer conveyor 74 is carried
upwardly by transfer conveyor 74 and is discharged into
side discharge chute 80 where it may be received by still
another ground-mounted conveyor belt or the like.
Material passing through third screen deck 5ûC and onto
transfer conveyor 74 and into side discharge chute 80 is
classified as fines.
The closed circuit system just described insures
2û that all of the raw material fed to the system by grizzly
22 (excluding the material retained on grate 23 of the
grizzly) will ultimately be discharged as an end product
through one of the side discharge chutes 70, 72, and 80.
When it is desired to place the apparatus in
condition for transport, the support structure 14û for the
elevating portion of conveyor-elevator 30 is folded down-
wardly from its elevated pos;tion as seen in Figs. 1 and 2
by folding upper support section 140B in a clockwise
direction relative to the views of the drawings about the
transverse pivotal axis 142 (Fig. 2) to the downwardly
folded position as seen in the transport position view of
Fig. 4. Swinging movement of the upper sup?ort section
140B relative to the lower support section 140A about the
transverse pivot axis 142 is effected by a power actuator
in the form of a doubLe-acting hydraulic jack 151 which
has its rod end pivotally connected to links 152, 153 on a
single transverse axis (which links are pivotally
connected to the upper and lower support sections 1408 and
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140A, respectively) and its rylinder end pivotally
connected to the elongated frame or chassis 16. Also,
hydraulic pressure in hydraulic cylinder 60 of hydraulic
ram or jack 58 (Fig. 2) is relieved, permitting piston rod
64 to retract into hydraulic cylinder 60, to thereby
permit vibrating screen 50 to move downwardly about its
pivotal connection 56 to trailer chassis 16 from the
upwardly inclined operating position shown in Fig. 2 to
the substantially horizontal transport position seen in
the view of Fig. 4. Also, the downward pivotal movement
of screen 50 about its pivotal axis 56 as just described
imparts a s;milar downward movement to transfer conveyor
74 since transfer conveyor 74 is structurally connected to
the understructure of screen 50, whereby to move transfer
conveyor 74 to a horizontal transport position in parallel
underlying relation to screen 50. Also for the transport
position, tractor 14 is connected to the forward end of
trailer 12 on which the portable crushing and screening
plant is mounted, and jack 20 is retracted to a raised
transport position permitting movement of the tractor-
trailer combination.
From the foregoing detailed description of the
invention, it has been shown how the objects of the
invention have been obtained in a preferred manner.
However, modifications and equivalents of the disclosed
concepts such as readily occur to those skilled in the art
are intended to be included within the scope of this
invention~
