Note: Descriptions are shown in the official language in which they were submitted.
1 337~29
Background of the Invention
This invention relates to dual lane conversion
systems. It is particularly adapted for conversion systems
making easy-open can ends, although it will be understood that
it could apply to presses manufacturing other types of parts.
Presses for converting ends for cans and the like
are known. Presses of this general type are available from
the Minster Machine Company of Minster, Ohio. U.S. patent no.
4,568,230 shows a general layout of a press for processing
work pieces or shells into finished can ends with an opening
tab attached thereto.
The presses used for the manufacture of easy-open
can ends generally comprise a press bed mounted on legs which
rest on the floor. Four columns or uprights or pillars are
mounted on the press bed. The columns support a crown in
which a main drive for the various press components is
mounted. The columns also have slides or ways attached
thereto for supporting a reciprocating ram. The ram carries
upper tooling, which cooperates with lower tooling on the bed.
The tooling defines a plurality of stations in which the
shells are progressively converted into easy-open can ends. A
conveyor carries the shells into and through the stations of
the die tooling. The shells merely rest in openings in the
conveyor. They are held in place by a vacuum box placed
generally underneath the forward run of the conveyor at the
area of the tooling.
The tabs are formed by tab tooling, which is
supplied with strip stock by a stock feed mechanism. The tab
tooling forms a tab and separates it from the strip stock, and
attaches it to a can end.
While presses as generally described above are
known, there remain several difficulties associated with the
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setup, operation and maintenance of the presses, which reduce
productivity. First, it can be appreciated that the various
moving parts of the press must be precisely aligned to assure
production of high quality parts. Most obviously, the upper
tooling which reciprocates on the ram must be precisely in
alignment with the stationary lower tooling. This requires
that the ram and, therefore, the columns be precisely located.
Similarly, the conveyor or transfer system must cooperate with
the tooling to place the work pieces or shells in the proper
place for conversion by the tooling. Operation of the
conveyor system is complicated by the fact that the shells
must be indexed through the stations of the die tooling not
only longitudinally, but also in a vertical direction to
accommodate the reciprocating motion of the upper tooling.
Location of the tab stock feeder mechanism further complicates
the alignment problems encountered in setting up the machine.
The second difficulty with prior art presses was
just eluded to, namely, the need to maintain registration of
the shells as they move from one station to the next. While
it is known to use a vacuum box to keep the shells from flying
off the conveyor entirely, prior art vacuum boxes make no
provision for the vertical motion of the upper tooling. That
is, in order to move the shells longitudinally from station to
station, they must be spaced from the upper and lower tooling
during indexing. However, during a downstroke of the ram the
shells must come into contact with the tooling in order for it
to perform conversion operations. In prior vacuum boxes this
vertical motion results simply by allowing flexure of the
conveyor belt under the influence of the upper tools driving
the shells and conveyor belt downwardly. This can lead to
loss of registration of the shells on the conveyor.
A third difficulty of prior press designs is the
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down time caused by inconvenient access to the tooling. A
primary reason for poor service access is the necessary
location of the tab stock feeder mechanism adjacent or
opposite the tooling. Thus,`only one side of the tooling is
accessible for maintenance purposes. While the tab stock
feeder ~echanism can be disassembled for access to the
tooling, such a process is time consuming and inconvenient.
The machine and its timing must be totally set up again,
because once the tab stock feeder is disconnected from the
drive, the necessary timing is lost.
Summary of the Invention
The present invention addresses each of the three
difficulties enumerated above. The alignment and registration
problems during setup are resolved by the present invention.
This is done by providing a unitary, elongated bolster which
fits between the press bed and the columns. That is, the
columns rest on the bolster rather than on the press bed.
Also, the die shoe of the lower tooling is located and affixed
to the bolster. Similarly, the conveyor or transfer system is
mounted on the bolster. The bolster has locators or keys
formed therein, which cooperate with similar alignment keys on
the lower die shoe, the columns, and the conveyor system.
This arrangement assures precise locations of all of these
cooperating parts of the press. Keys are provided to locate
the columns both longitudinally and laterally of the bolster.
Thus, the bolster integrates support of the press elements.
Registration of the shells on the conveyor is main-
tained by a traveling vacuum box. The vacuum box has a case
mounted on the lower die shoe, and a frame which is vertically
slidable within the case. The frame has edge tracks which
engage the lateral edges of the conveyor as it moves through
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the vacuum box. It also includes a central guide. Flanges on
the tracks and guide overlie the upper surface of the conveyor
such that the edges of the shells are trapped against vertical
separation from the conveyor. Thus, the shells are positive-
ly retained in position on the conveyor, in addition to thevacuum retention.
The frame is mounted on spring supports, and there
are actuators depending from the upper die shoe on the ram.
These actuators are also spring loaded with springs that are
stronger than those of the frame supports. The actuators are
sized to contact the frame prior to the ram reaching the
bottom of its downstroke. This pushes the frame downwardly,
and carries the shells into contact with the lower tooling.
When the frame bottoms out, the springs of the actuators
compress, providing a lost motion which allows the ram to
reach bottom dead center without damaging the vacuum box. On
the upstroke of the ram, the actuators will hold the frame in
its down position until the upper tools have moved out of
contact with the shells. Once that occurs, the frame will
move back up to its raised position under the influence of the
frame supports. This raises the shells off of the lower
tooling where they are ready for indexing to the next station.
Access to the tooling is facilitated by a hinged tab
stock feeder mechanism. The feeders are located within a
carrier which is mounted on one of the columns. The carrier
is pivotable away from the tooling about a hinge line.
Mechanical power is supplied from the main drive to the
feeders through a drive shaft which is coaxial with the hinge
line. This permits pivoting motion of the carrier without
disconnecting the drive. Consequently, the timing between the
feeder and the other parts of the press is not lost when the
feeder carrier is pivoted to its service position.
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1 A press for converting work pieces into parts,
comprising a bed, a bolster mounted on the bed, a
plurality of columns mounted on the bolster and having a
way attached to each column, main drive means mounted on
the columns, a ram slidable upon the ways and driven by
the main drive means to reciprocate toward and away from
the bolster, upper and lower tooling means attached to the
ram and bolster, respectively, having a plurality of
stations for converting said work pieces into parts,
conveyor drive means mounted on the bolster, and conveyor
means mounted on the conveyor drive means for carrying
work pieces into and through the tooling means stations,
the bolster comprising a one-piece member which includes
locating means engageable with the conveyor drive means,
columns and lower tooling means for establishing the
correct positions of the conveyor drive means, the columns
and the lower tooling means with respect to one another,
such that they are aligned for cooperation.
A press for converting work pieces into parts,
comprising a bed, a plurality of columns mounted on the
bed and having a way attached to each column, main drive
means mounted on the columns, a ram slidable upon the ways
and driven by the main drive means to reciprocate toward
and away from the bed, upper and lower tooling means
attached to the ram and bed, respectively, having a
plurality of stations for processing said work pieces into
parts, conveyor drive means mounted on the bed, and
conveyor means mounted on the conveyor drive means for
carrying work pieces into and through the tooling means
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1 337029
1 stations, a feeder carrier mounted on a column opposite
the tooling means and pivotable about a hinge line away
from the tooling means to provide service access thereto,
stock feed means mounted on the feeder carrier for feeding
a strip stock into the stations of the tooling means,
feeder drive means connected to the main drive means for
driving said stock feed means, the feeder drive means
including a drive shaft mounted coaxially with the hinge
line so as to permit pivoting of the feeder carrier
without disconnecting the feeder drive means from the
stock feed means.
A press for converting work pieces into parts,
comprising a bed, a plurality of columns mounted on the
bed and having a way attached to each column, main drive
means mounted on the column, a ram slidable upon the ways
and driven by the main drive means to reciprocate toward
and away from the bed, upper and lower tooling means
attached to the ram and bed, respectively, having a
plurality of stations for processing said work pieces into
parts, a feeder carrier mounted on a column opposite the
tooling means and pivotable about a hinge line away from
the tooling means to provide service access thereto, stock
feed means mounted on the feeder carrier for feeding strip
stock into the stations of the tooling means, feeder drive
means connected to the main drive means for driving said
stock feed means, the feeder drive means including a drive
shaft mounted coaxially with the hinge line so as to
permit pivoting of the feeder carrier without
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1 337029
1 disconnecting the feeder drive means from the stock feedmeans.
In the press for converting work pieces into parts,
the press having lower tooling including a tool shoe
mounted on a bed and upper tooling mounted on a
reciprocating ram which moves the upper tooling into and
out of 9operative engagement with the lower tooling the
upper and a lower tooling having a plurality of stations
where work is performed on the work pieces, and an endless
conveyor having a forward run disposed between the upper
and lower tooling for successively advancing work pieces
to each of the stations of the tooling, the conveyor
having openings therein in which work pieces rest normally
spaced from the tooling, the improvement comprising a
travelling vacuum box which applies a vacuum to the side
of the conveyor opposite the work pieces so as to hold
them on the conveyor, the vacuum box comprising:
an open-top case surrounding the lower tooling
stations and fixed to the lower tool shoe; and
a frame engageable with the case and vertically
slidable with respect to the case, at least one of the
frame and case having seal means engageable with the other
such that the frame and case are slidable in sealing
relation, the frame having a pair of inwardly-facing,
longitudinal tracks which support the lateral edges of the
conveyor such that the conveyor moves vertically with the
frame, the frame being open on its top and bottom to
permit access by the top and bottom tooling to the work
pieces.
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1 337029
Brief Description of the Drawings
Fig. 1 is a front elevation view of the conversion
system of the present invention.
Fig. 2 is an end elevation view of the conversion
system, looking from the right side of Fig 1.
Fig. 3 is a top plan view of the bolster with the
lower die shoe omitted for clarity.
Fig. 4 is an enlarged front elevation view of the
bolster, with portions omitted, showing the conveyor system
mounted thereon.
Fig. 5 is an end elevation view of the bolster
looking from the right end of Fig. 4.
Fig. 6 is an elevation view of the tab stock feeder
mechanism, looking in the direction of line 6-6 of Fig. 2.
Fig. 7 is a plan view of the tab stock feeder mecha-
nism.
Fig. 8 is an enlarged front elevation view of the
tab feeder, with the cover omitted.
Fig. 9 is a side elevation view of the tab stock
feeder, looking from the right side of Fig. 8.
Fig. 10 is a side elevation view of the tab stock
feeder, looking from the left side of Fig. 8.
Fig. 11 is a diagrammatic perspective view of the
vacuum box and associated apparatus.
Fig. 12 is a section taken generally along line 12-
12 of Fig. 11, with the ram in a raised position.
Fig. 13 is a section taken generally along line 13-
13 of Fig. 11, with the ram in a lowered position.
Fig. 14 is a detail view showing the construction of
the vacuum box frame.
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Detailed Description of the Invention
The conversion system or press is shown generally at
10 in Figs. 1 and 2. For purposes of description, the portion
of the press shown in Fig. 1 will be termed the front of the
machine. The right hand side as seen in Fig. 1 will be called
the input side with the left hand side referred to as the
output side. The side not shown in Fig. 1 will be denoted the
back of the machine. The press includes a pair of legs 12
supporting a press bed 14. Certain auxiliary equipment such
as a vacuum pump 16, and a vacuum manifold 18 may be attached
to the press bed.
A unitary bolster 20 rests on top of the press bed
14, and is keyed thereto as at 22. It will be noted that the
bolster 20 extends beyond the edges of the bed 14. Details of
the inventive bolster will be described below.
Four columns or uprights 24 are mounted on top of
the bolster 20. Each column includes a way or track 25. A
crown 26 is supported on top of the columns 24. The bed 14,
bolster 20, columns 24 and crown 26 are fastened together by
tie rods 27 extending through these components. Inside the
crown is a main drive means, including a motor, crankshaft,
and flywheel (not shown). The various components of the press
are driven by means of mechanical connections to the crank-
shaft. For example, rotary down stackers 28 which place
shells onto a conveyor are driven by belts connected to the
crankshaft. The housings for the belts are shown at 30. They
are connected to gear boxes 32. Drive shafts shown schemati-
cally at 34 connect the gear boxes 32 to the down stackers.
A ram 36 is slidable on the ways 25. It is driven
by the crankshaft in a reciprocating motion. Tooling shown
generally at 38 is located between the ram 36, and the bolster
20. The tooling shown is lane and tab tooling for converting
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can ends. This tooling comprises the usual dies and punches
required to form the ends. As is customary, the tooling is
divided into upper and lower sets, including an upper die shoe
40, and a lower die shoe 42. The upper shoe 40 is affixed to
the ram 36, and moves therewith. The lower die shoe is keyed
to the bolster 20, as described below. The usual die fixtures
and punch holders are mounted on the die shoes. A traveling
vacuum box is indicated schematically at 44.
The press includes a transfer or conveyor system,
including a main gear box 46 driven from the crankshaft by
belt 47 (seen in Fig.4). The gear box 46 drives a head end
pulley 48, which is mounted for rotation on a pair of brackets
50. The brackets are attached to the bolster. A tail end
pulley 52 is mounted at the other of the bolster. It is
covered by a shroud 54. An endless conveyor belt illustrated
schematically at 56 is driven by the pulley 48, and revolves
about pulley 52. The belt 56 has openings 57 for receiving
shells.
A strip stock feeder shown generally at 58 is
20- mounted at the back of the press, opposite the area of the
tooling. This apparatus feeds a strip stock material which,
in the embodiment shown, is used to make the tab parts of the
can ends. Details of the stock feed mechanism 58 will be
described below.
Turning now to Figs. 3-5, details of the bolster 20
and the conveyor system are shown. The bolster is an
elongated slab of steel, approximately 6 inches thick. The
upper surface of the bolster has a plurality of locating means
in the form of keyways for establishing the positions of
components mounted on the bolster, namely, the columns 24 and
lower die shoe 42. There is a lateral keyway 60 for each of
the columns, which is aligned with a matching keyway 62 (Fig.
~ _q ~ 3 3 7 ~ 2 9
4) on the bottom of the columns to precisely set the position
of the columns along the length of the bolster. A key 61 fits
into the matching keyways. The two columns at the rear of the
bolster also have longitudinal keyways 64 (Fig. 3). These
keys fix the lateral position of the rear two columns.
Central keyways 66 establish the center line of the bolster.
They are used to fix the lower die shoe 42 in position. They
also establish a reference line for drilling the bolt holes
used to mount the brackets 50. The keyways 60 and 64 are
machined into the bolster with reference to the central
keyways.
The bolster has vacuum supply ports 68 in communica-
tion with passages 70, which extend through the bolster.
Passages 70 are connected to the vacuum manifold 18 through
mating passages in the bed 14.
The input end of the bolster has a U-shaped cutout
shown at 72. The cutout forms a pair of arms 74. The U-
shaped cutout 72 accommodates the tail end pulley 52 between
the arms 74. Immediately adjacent the cutout, on the upper
surface of the bolster is a depression 76. A saddle 78 fits
in the depression 76, and carries the bearings for mounting
the tail end pulley 52. A cylinder 80 is mounted between the
bolster and the saddle 78 for adjusting the longitudinal
position of the saddle, thereby controlling the tension on the
conveyor belt 56. A pair of restraining bars 82 are fixed to
the bolster arms 74 to hold the saddle in the depression 76.
The conveyor belt 56 is supported on its forward run
adjacent the tail end pulley 52 by a plate 84. The plate is
mounted on a bridge structure 86 attached to the bolster. The
bridge 86 also supports the down stackers 28.
From the plate 84 the forward run of the conveyor
progresses between two of the columns 24, and then into the
1 3 3 7029
area of the tooling. The forward run of the conveyor is
supported in the tooling area by the vacuum box 44, as will be
described in detail below. Upon leaving the tooling area, the
forward run of the conveyor proceeds between the two output
side columns to an output d-evice where the finished can ends
are discharged. The conveyor belt winds around the head end
or drive pulley 48 to begin the return run. The return run is
accommodated by a channel 88 cut in the underside of the
bolster as shown in Fig. 4.
The bolster 20 provides an integrated support member
for the various press components. In the embodiment shown the
bolster extends beyond the columns to provide support for the
transfer system or conveyor. The bolster also assures proper
alignment of the components mounted thereon.
Looking now at Figs. 6-10, the stock feed mechanism
58 is shown in detail. Although it could be used to feed any
type of work pieces or stock, in the illustrated embodiment it
is used to feed the tab stock strip, so hereinafter the stock
feeder will be referred to as the tab feeder. Since the
feeder is supplying the tab stock to the tab tooling, it is
located opposite or adjacent-to the tab tooling, on the rear
side of the machine. Thus, the tab stock is fed transversely
to the direction of the main conveyor belt. As a result of
this required positioning for the feeder, it blocks service
access to the tooling. The present invention alleviates this
difficulty by pivotally mounting the tab feeder 58 to one of
the columns 24. The feeder pivots about a hinge line from its
normal working position to a service position shown in phantom
at 90 in Fig. 7.
The feeder components are mounted on a carrier
comprising top and bottom plates 92 and 94, and first and
second side plates 96 and 98. A removable cover 100 encloses
1 337029
"
the carrier on three sides.
The feeder carrier is pivotally mounted by a bracket
118, which is bolted to a column 24. The bracket includes a
stiffener 120, and upper and lower extensions 122. The exten-
sions mount bearings about which the top and bottom plates arepivotable. These bearings define a hinge line or rotational
axis 124.
The first side plate 96 carries a pair of locating
pads 102 and 104 (Fig. 10), which define horizontal and
vertical locating surfaces, respectively. The first side
plate also has a pin 106, on which a latch 108 is pivotally
mounted.
The rear edge of the lower die shoe 42 has milled
surfaces 110 and 112. When the feeder is in the closed or
operating position, the pads 102 and 104 of the first end
plate engage these milled surfaces to locate the carrier in
the correct position with respect to the die shoe. Immediate-
ly adjacent these milled surfaces is a slot 114 into which a
hook portion of the latch 108 fits to engage a removable bolt
116 for holding the feeder in the closed position.
The actual apparatus for feeding the tab stock is
conventional, and may be purchased from Fergurson Manufactur-
ing of St. Louis, Missouri. Briefly, that mechanism includes
a right angle gear box 126 having a shaft 128, which is
coaxial with the hinge line 124. Gear box 126 drives a belt
130 about an adjustable idler 132, which is mounted on the
second side plate 98. The side plate has a U-shaped cutout
134 permitting passage of the belt and idler. The belt 130
drives a stock input device 136 and a stock output device 138.
The stock itself is shown diagrammatically at 140 in Fig. 7.
It will be understood that associated equipment, such as lube
units and a scrap chopper have been omitted or only partially
1 337029
shown. ~1~~
Nechanical power to the gear box 126 is provided
through a belt 142, driven by a right angle drive 144 (Figs. 6
and 7). This drive in turn receives power from belt 146,
which engages an output shaft of the main gear box 46.
It can be seen that with this drive arrangement the
carrier can be rotated about the hinge line 124 without the
need for disconnecting any of the belts. The timing of the
tab feeders is not lost when the carrier pivots between
operating and service positions. The locating surfaces on
pads 102 and 104 assure that the carrier will always line up
in the correct position with respect to the lower die shoe.
Looking now at Figs. 11-14, the traveling vacuum box
44 is shown in detail. The vacuum box 44 is located on the
lower die shoe 42. The lower die shoe also has a plurality of
guide sleeves 148 fixed thereto. Guide posts 150 depending
from the upper die shoe 40, slide in the sleeves 148 to
maintain registration between the upper and lower tooling.
The upper and lower die shoes also have stop blocks 152, which
limit the downward motion of the die shoe 40. A plurality of
tool holders or fixtures 154, which define the progressive
work stations of the tooling, are fixed to the upper and lower
die shoes.
The traveling vacuum box itself comprises an open-
top case 156 bolted to the lower die shoe 42. The case
surrounds the tool holders 154 of the work stations. The
upper inside edge of the case has a seal element 158 (Fig.
14). The case also includes end blocks 160 (Figs. 11 and 13).
The end blocks mount stop members 162 and 164. Stops 162 may
be retained by bolts 165. The interior of the case communi-
cates with vacuum supply passages 166 (Fig. 12) formed in the
die plate 42. These communicate with the vacuum ports 68 in
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the bolster.
The vacuum box also includes a traveling frame shown
generally at 168. The ends of the frame are defined by belt
lowering bars 170 on each end. The belt lowering bars have
corner members through which bolts connect the bars to end
support rails 172. The end support rails 172 have openings
174, which accommodate the stop members 162. The openings 174
and stops 162 cooperate to provide an up limit stop for the
frame 168. The end support rails 172 are also bolted to
spring-loaded frame supports 176. These supports extend
through the blocks 160 into receptacles in the lower die shoe
42. Springs 178 bias the frame upwardly. There is a frame
support 176 at each corner of the frame.
The belt lowering bars 170 and end support rails 172
are connected by three sets of rails, each having an upper and
lower member. An upper center rail 180 is attached to the
belt lowering bars 170, and located by a spacer 182. As best
seen in Fig. 12 the upper center rail 180 has three central
ribs 183, and corners 184. A lower center rail 186 is
connected to the end support rails 172 and has dimples 187.
First and second sets of outer rails include a top
outer rail 188, which is a generally Z-shaped part with its
upper surface having a single rib 190 and a lip or flange 192.
The top outer rails cooperate with lower outer rails 194,
which are channel shaped members having a pair of dimples 195
on its upper edge. The ends of the lower outer rails are
attached to the end support rails 172. It will be noted that
the outside surfaces of the lower outer rails 194 engage the
seals 15~ of the case in sealing relation. Together the upper
and lower outer rails 188 and 194 define tracks in which the
forward run of the conveyor belt 56 travels.
The upper die shoe 40 has four sockets in which
ILl 1 337~29
actuators 196 are placed. The actuators are biased downwardly
by springs 198. The movement of the actuators within the
socket is constrained by flanges 200, which are trapped
between a stop 202 and a plate 204. The actuators have feet
S 206, which are engageable with the belt lowering bar 170 when
the ram lowers the die shoe 40. The springs 198 have a higher
spring rate than that of springs 178.
The operation of the vacuum box is as follows. The
conveyor 56 is threaded through the three sets of rails in the
vacuum box frame 168. That is, the lateral edges of the
conveyor belt are held in the tracks formed by the upper and
lower outer rails 188 and 194. In particular, the outer edges
of the belt are held between the ribs 190 and dimples 195.
This is best seen in Fig. 14. The center of the belt is
trapped between center rails 180 and 186, and particularly
between the ribs 183 and dimples 187. Thus, the conveyor belt
56 is constrained to travel with the frame of the vacuum box.
The shells are shown at 208. They rest in the
openings 57 in the conveyor belt 56. The lateral edges of the
shells are trapped between the belt on the underside, and the
lips or flanges 192 of the outer rails, and the corners 184 of
the center upper rail. Thus, the shells are positively held
in place in the conveyor belt by the lips 192, and corners
184, as well as being held by the vacuum in the interior of
the vacuum box 44.
During a downstroke of the ram, the upper die plate
40 carries the actuators 196 into engagement with the belt
lowering bars 170. Since the actuator springs 198 are stiffer
than the frame support springs 178, the actuators force the
frame 168 downwardly until the stops 164 bottom on the blocks
160. As the frame travels down it carries the conveyor belt
56 with it, thereby carrying the shells into contact with the
~ 1 337029
lower tools prior to the upper tools coming down on the
shells. When the frame bottoms, the actuator springs 198
compress within the upper die shoe sockets to allow the ram to
carry the upper tools to bottom dead center without damaging
the vacuum box. Upon retraction of the ram, the tools leave
contact with the shells first, and then the actuator stops 202
engage the flange 200 to lift the actuators off of the vacuum
box frame. As the actuators rise, the frame also moves
upwardly under the influence of its support springs 178 until
10- slots 174 engage stops 162. Once the shells are out of
contact with the lower tools, the conveyor belt indexes them
forwardly to the next work station.
Nhile a preferred form of the invention has been
shown and described, it will be understood that alterations
could be made thereto without departing from the scope of the
following claims.
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