U.S. patent application number 15/386288 was filed with the patent office on 2017-06-22 for post mounting assembly and method for molten metal pump.
The applicant listed for this patent is Karl E. Greer. Invention is credited to Karl E. Greer.
Application Number | 20170175772 15/386288 |
Document ID | / |
Family ID | 59066062 |
Filed Date | 2017-06-22 |
United States Patent
Application |
20170175772 |
Kind Code |
A1 |
Greer; Karl E. |
June 22, 2017 |
Post Mounting Assembly and Method for Molten Metal Pump
Abstract
A molten metal pump apparatus that includes a base member, at
least two (2) support members or posts, and a post socket. The
lower end of each post is mounted to a mounting bore of the base
member and forms a cement-less pump joint. The upper end of the
post is connected to the post socket to form a cement-less pump
joint. The post socket is defined by a first half and a second half
that have an open or separated position for receiving the upper end
of the post and a closed or joined position for securing the upper
end of the post.
Inventors: |
Greer; Karl E.; (Lewisport,
KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Greer; Karl E. |
Lewisport |
KY |
US |
|
|
Family ID: |
59066062 |
Appl. No.: |
15/386288 |
Filed: |
December 21, 2016 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62270357 |
Dec 21, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/20 20130101;
F04D 29/605 20130101; F04D 7/065 20130101 |
International
Class: |
F04D 29/60 20060101
F04D029/60; F04D 7/06 20060101 F04D007/06 |
Claims
1. A post mounting assembly for a molten metal pump, said post
mounting assembly comprising: a pump base to be submerged in molten
metal, a post socket assembly including a plate member supported
above a level of the molten metal by at least two (2) vertical
support posts, each of said at least two (2) vertical support posts
having a longitudinal length that extends from said pump base to
said post socket assembly, wherein each of said at least two (2)
vertical support posts include an upper end for connecting to said
post socket assembly and a lower end for connecting to said pump
base, wherein said pump base includes at least two (2) mounting
bores that each define a void that extends completely through the
pump base, said void having a length, and wherein each of said
mounting bores configured for receiving said lower end of said post
and having a substantially circular configuration and including at
least one (1) tab member that defines a flat surface and a lower
edge, said at least one (1) tab member having a vertical length,
and wherein said length is greater than said vertical length, and
wherein each mounting bore further defines a first distance that
equals the diameter of the mounting bore at a point that includes
the at least one (1) tab member, and a second distance that equals
the diameter of the mounting bore below the lower edge that does
not include the at least one (1) tab member, and wherein said lower
end includes at least one (1) flat surface configured to mate with
said flat surface of said at least one (1) tab member, and said
lower end further includes a stop and a ledge, said upper end is
sized for receipt within an interior of a housing of said post
socket assembly and wherein said plate member and housing are
defined by a first half and a second half that have an open or
separated position and a closed or joined position.
2. The assembly of claim 1, wherein each of said at least two (2)
vertical support posts include a protective sleeve configured for
protecting a defined mid-section of each of said posts.
3. The assembly of claim 2, wherein each of said at least two (2)
vertical support posts include a first groove that horizontally
extends around said post and is disposed within said defined
mid-section.
4. The assembly of claim 3, wherein each of said at least two (2)
vertical support posts include a second groove that horizontally
extends around a lower portion of said defined mid-section, and
wherein said first groove horizontally extends around an upper
portion of said defined mid-section.
5. The assembly of claim 2, wherein each of said at least two (2)
vertical support posts include at least one (1) groove that
vertically extends an approximate length of said defined
mid-section.
6. The assembly of claim 2, wherein each of said at least two (2)
vertical support posts include a plurality of notches that include
a first notch disposed at a lower portion of said defined
mid-section and a second notch disposed at an upper portion of said
defined mid-section.
7. A post mounting assembly for a molten metal pump, said post
mounting assembly comprising: a pump base, a post socket assembly
that includes a plate member and a housing, said plate member
configured for attaching to a pump's motor mounting plate, and at
least two (2) vertical support posts, each of said posts having a
longitudinal length that extends from said pump base to said post
socket assembly, wherein said pump base includes at least two (2)
mounting bores that define a void, and wherein said void having a
length, and said bores including at least one (1) tab member that
defines a flat surface and a lower edge, and wherein said tab
member having a vertical length, and wherein said length is greater
than said vertical length, and wherein each mounting bore defines a
first distance that equals the diameter of the mounting bore at a
point that includes the at least one (1) tab member, and a second
distance that equals the diameter of the mounting bore below the
lower edge that does not include the at least one (1) tab member,
and wherein a lower end of each of said at least two (2) vertical
support posts include at least one (1) flat surface configured to
mate with said flat surface of said tab member, said lower end
further includes a stop and a ledge, and wherein an upper end of
each of said two (2) vertical support posts is sized for receipt
within an interior of said housing, and wherein said plate member
and housing are defined by a first half and a second half that have
an open or separated position and a closed or joined position.
8. The assembly of claim 7, wherein each of said at least two (2)
vertical support posts include a defined mid-section, and includes
a protection sleeve that substantially covers said defined
mid-section.
9. The assembly of claim 8, wherein each of said at least two (2)
vertical support posts further include a first groove that
horizontally extends around said post and is disposed within said
defined mid-section.
10. The assembly of claim 9, wherein each of said at least two (2)
vertical support posts include a second groove that horizontally
extends around a lower portion of said defined mid-section, and
wherein said first groove horizontally extends around an upper
portion of said defined mid-section.
11. The assembly of claim 8, wherein each of said at least two (2)
vertical support posts include at least one (1) groove that
vertically extends an approximate length of said defined
mid-section.
12. The assembly of claim 8, wherein each of said at least two (2)
vertical support posts include a plurality of notches that include
a first notch disposed at a lower portion of said defined
mid-section and a second notch disposed at an upper portion of said
defined mid-section.
13. A method for assembling a post mounted assembly for a molten
metal pump comprising the steps: aligning at least one (1) flat
surface of a support post's lower end with a flat surface of a
mounting bore disposed in a pump base, inserting said lower end in
said mounting bore until a stop on said lower end is in abutting
contact with a top surface of said pump base, rotating said lower
end within said mounting bore until said support post is in locking
engagement with said pump base, attaching a first half of a post
socket to a pump's motor mounting plate, positioning an upper end
of said support post within a defined interior portion of said
first half, aligning a first aperture in said first half with an
aperture in said upper end of said support post, inserting a pin
member through said first aperture and partially through said
aperture of said upper end, positioning a second half of said post
socket with said upper end of said post and with said first half
aligning a second aperture in said second half with said aperture
in said upper end, urging said pin member through said aperture in
said upper end and through said second aperture, securing said pin
member with a retainer, and attaching said second half to the
pump's motor mounting plate.
14. The method of claim 13, including the step of pouring a fill
composition into a mold between a side of the mold and a defined
mid-section of said support post.
15. The method of claim 14, wherein said support post includes a
first groove that horizontally extends around said support post and
is disposed within said defined mid-section.
16. The method of claim 15, wherein said support post includes a
second groove that horizontally extends around a lower portion of
said defined mid-section, and wherein said first groove extends
around an upper portion of said defined mid-section.
17. The method of claim 14, wherein said support post includes at
least one (1) groove that vertically extends an approximate length
of said defined mid-section.
18. The method of claim 14, wherein said support post includes a
plurality of notches that includes a first notch disposed at a
lower portion of said defined mid-section and second notch disposed
at an upper portion of said defined mid-section.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] U.S. Provisional Application for Patent No. 62/270,357,
filed Dec. 21, 2015, with title "Post Mounting Assembly and Method
for Molten Metal Pump" which is hereby incorporated by reference.
Applicant claims priority pursuant to 35 U.S.C. Par. 119(e)(i).
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED
RESEARCH AND DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention relates to pumping molten metal and more
particularly to molten metal pump apparatus and methods for
assembling and disassembling such apparatus.
[0005] 2. Brief Description of Prior Art
[0006] A molten metal pump apparatus generally includes a motor
mounted above a molten metal bath. The motor drives a rotatable
impeller pump having one or more impellers submerged in the bath.
In operation, the rotating impellers draw molten material from the
bath and pump it through a conduit routed to a subsequent station
for further processing.
[0007] The molten metal pump typically includes a base having inlet
and outlet passages for intake and discharge of the molten metal
being pumped. The pump base together with the impeller are
submerged in the molten metal, supported on the bottom of the
vessel containing the molten metal. The pump base is typically
connected by refractory cement and/or mechanical arrangements to a
plurality of vertically extending support posts which are also
connected to a drive arrangement positioned above the level molten
metal. In typical installations, these vertically extending posts
may be several feet long, e.g. one to four feet in length or
longer, in order to provide adequate clearance between the molten
metal level.
[0008] The portions of the pump assembly submerged in the molten
metal are directly contacted and exposed to the harsh conditions
thereof, and are formed of refractory material such as graphite,
silicone carbide, alumina, zirconia or hexalloy. The posts extend
through a level of the molten metal and are connected to a motor
mounting plate of the drive arrangement positioned above the level
molten metal.
[0009] In prior art arrangements, downwardly opening post sockets
are fixed to the motor mounting plate and receive the upper ends of
the posts. One or more post sockets may be fixed to a post support
plate, as by welding, and the support plate is secured to the motor
mounting plate. In prior art arrangements, the posts may also be
secured within the post's sockets by means of a refractory cement,
bolts or other clamping devices.
[0010] Despite the positive properties for this described
application, graphite and ceramics still corrode and deteriorate
over time. The vertical posts that extend through a level of molten
metal begin to erode as a result of use and molten metal pumps must
be more frequently maintained and replaced than other types of
pumps. The replacement or servicing of a pump having operating
components submersed in molten metal is a time consuming exercise.
First, the pump must be removed from the molten metal which
generally causes down time. Then the pump along with the molten
metal contained thereon must be allowed to sufficiently cool to
allow it to be disassembled. Once the deteriorated components are
sufficiently cooled, the vertical posts that have sufficiently
deteriorated are replaced, and the molten metal buildup on the
various pump surfaces must be sufficiently removed to allow
disassembly and/or re-use of the pump components. Then the pump
must be reassembled with the combination of old components or
parts, along with the replacement parts.
[0011] As previously described, there are certain components of the
pump which are typically cemented together in order to achieve a
balanced and sufficiently rigid pump structure to allow continuous
operation of the pump. However, when the pump must be disassembled,
the cemented joints can be very difficult to disassemble.
[0012] In the case of the vertical posts between the pump base and
the motor mount structure, the posts have traditionally been
cemented into bored holes within the base. In the case of the base
for example, when the pump is disassembled, the cemented portion of
the posts must normally then be chipped, dug or drilled out in
order to allow a new post to be placed in the same bore. This makes
the disassembly much more difficult. A most significant
disadvantage to prior art arrangements is therefore the need to
cleanly remove the post when it is necessary to replace the
post.
[0013] Further, during assembly of the pump, it is important that
the pump components be accurately aligned in order for the pump
system to work efficiently once it is back in the molten metal. The
combination of the components are very heavy, and once the posts
for example are cemented in place as described above, it is then
very difficult if not impossible to align if necessary.
[0014] As will be seen from the subsequent description, the
preferred embodiments of the present invention overcome
shortcomings of the prior art.
SUMMARY OF THE INVENTION
[0015] A post mounting assembly for assembling and disassembling a
molten metal pump. The post mounting assembly includes a pump base,
at least two (2) support members or posts, and post sockets. Each
post may include a protective sleeve that surrounds the post's
mid-section. The post socket having a first half and a second half
that when joined defines a body portion for receiving an upper end
of the post.
[0016] The assembly of the posts to the mounting base illustrates
an embodiment of a cement-less pump joint which is an objective of
the present invention. Further, the assembly of the post to the
post socket illustrates an embodiment of a cement-less pump joint
which is a further object of the present invention. As a result, a
replacement post identical to posts of the present invention may be
provided without the need to dig out a cement joint but instead can
be more easily removed and replaced.
[0017] The base of the present invention includes at least two (2)
mounting bores therethrough for receiving the lower end of the
post. Each mounting bore includes at least one tab disposed
substantially adjacent the upper surface of the base member. The at
least one tab includes flat surfaces that align with flat surfaces
disposed on the lower end of the posts such that the lower end of
the posts can be inserted in the mounting bores and rotating the
posts within the mounting bores effectively secures the posts to
the base member.
[0018] The upper end of the posts are shaped and sized to be
received within the post socket. The post socket and the upper end
of the posts include apertures for alignment and for receipt of a
pin member that secures the upper end of the post to the post
socket. The coupling configuration between the upper end of the
post and the post socket provides very tight tolerances such that
the joint connection as described does not require equipment to
align the pump during assembly and installation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a top perspective view of a pump base for a molten
metal pump.
[0020] FIG. 2 illustrates one of the bored holes within the pump
base for mounting a vertical post.
[0021] FIG. 3 illustrates a vertically extending post with a
portion of the protective sleeve removed for illustration.
[0022] FIG. 4 illustrates an upper end of the post of FIG. 3.
[0023] FIG. 5 illustrates a lower end of the post of FIG. 3.
[0024] FIG. 6 is a top perspective view of a post socket.
[0025] FIG. 7 is an alternate embodiment of the vertically
extending post with a portion of the protective sleeve removed for
illustration.
[0026] FIG. 8 is a second alternate embodiment of the vertically
extending post with a portion of the protective sleeve removed for
illustration.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] In accordance with the present invention, a post mounting
assembly and method for molten metal pump is disclosed. The post
mounting assembly is directed to a molten metal pump apparatus and
method for assembling and disassembling such apparatus.
Specifically, it will be noted in the drawings that the post
mounting assembly provides a pump assembly which does not require
as many or any cemented joints as does prior art pumps. Further,
the present invention provides a pump and assembly system which
tends to self-align the pump during the assembly process thereby
reducing or eliminating the need for alignment apparatuses. In the
broadest context, the post mounting assembly for molten metal pump
consists of components configured and correlated with respect to
each other so as to attain the desired objective.
[0028] FIGS. 1-6 illustrate a preferred embodiment of a post
mounting assembly made in accordance with the present invention.
The assembly of the present invention includes a pump base 10
(shown in FIG. 1), at least two (2) support members or posts 20
(shown in FIGS. 3-5), and a post socket assembly 30 shown in (FIG.
6).
[0029] A molten metal pump (not shown) generally includes a base
having an impeller mounted therein. The impeller is secured to a
driveshaft mounted for rotation within the base. The upper end of
the driveshaft is connected to a motor.
[0030] The pump further includes at least two (2) identical
vertical support members that are spaced apart to provide
stability. Each of the vertical support members include an end for
connection to a motor mounting plate. Each of the support members
further include an end for connection to the base.
[0031] Referring to FIG. 3, the at least two (2) support members or
posts illustrated as numeral 20 for the present invention include
an upper end 22 for connection to the motor mounting plate, and a
lower end 24 for connection to the base member 10. Each upper end
22 of the posts 20 are connected to the motor mounting plate using
the post socket 30. The post socket assembly 30 is described below
in greater detail.
[0032] Referring to FIGS. 1-2, the base member 10 includes at least
two (2) mounting bores 12 therethrough for receiving the lower end
24 of the post 20. As stated, the mounting bores 12 define a void
completely through the base member 10. As shown, the mounting bores
12 have a substantially circular configuration and each mounting
bore 12 includes at least one tab member 14 that is vertical the
upper surface 10A of the base member 10. As illustrated, a top edge
14A of each tab member 14 is substantially adjacent the upper
surface 10A. Each tab member 14 further defines a flat surface 15
within the mounting bore 12 (best shown in FIG. 2), and a lower
edge 16.
[0033] As shown in FIG. 2, each of the mounting bores 12 include a
first distance designated as "D1" which is the diameter of the bore
12 with the at least one tab member 14, and a second distance
designated as "D2" (shown in FIG. 1) which is the diameter of the
bore 12 below the lower edge 16 of the at least one tab member 14.
The first distance D1 is less than the second distance D2 of the
mounting bore 12.
[0034] FIG. 5 best shows the lower end 24 of the posts 20. The
lower end 24 sized and shaped to be received within the mounting
bore 12 of the base 10. More particularly, the lower end 24, like
the mounting bore 12 includes at least one flat surface 25 and a
surface 28 adjacent each of the at least one flat surface 25.
[0035] In application, aligning the at least one flat surface 25 of
the post's lower end 24 with the flat surface 15 of the mounting
bore 12 enables the lower end 24 of the posts 20 to be inserted in
the mounting bore 12 until the upper surface 10A is in contact with
a stop 27 of the lower end 24. Further, once the stop 27 is in
contact with the upper surface 10A as described, the post's lower
end 24 will be disposed within the mounting bore 12 and below the
lower edge 16 of the at least one tab member 14 such that a ledge
29 of the lower end 24 is in abutting communications with the lower
edge 16. As illustrated, the ledge 29 is adjacent the surfaces 25,
28. In this position, the post 20 can rotate within the bore
12.
[0036] Once the lower end 24 is inserted in the mounting bore 12 as
described, rotating the post 20 within the mounting bore 12
effectively secures the post 20 to the base member 10.
[0037] As should be understood, further rotating the post 20 within
the mounting bore 12 until the surfaces 15 and 25 are aligned
releases the post 20 from the mounting bore 12.
[0038] The assembly of the lower end 24 of the posts 20 to the
mounting base 10 as described illustrates an embodiment of a
cement-less pump joint which is an objective of the present
invention. Therefore a replacement post identical to post 20 may be
provided without the need to dig out a cement joint but instead can
be more easily removed and replaced.
[0039] Referring to FIG. 6, a post socket assembly 30 generally
includes an upper plate 31 and a body portion 32. In application,
the upper plate 31 is secured to the pump's motor mounting plate
(not shown) in any convenient manner, such as, threaded fasteners.
The body portion 32 having an opening 33 to access an interior 34.
The opening 33 and interior 34 are sized for receipt of the upper
end 22 of the post 20.
[0040] As will be further described, the upper end 22 of the post
20 is secured within the interior 34 of the body portion 32 with a
pin member (not shown) known in the art that in application, is
inserted through a post aperture 26 (see FIG. 4) that extends
through the upper end 22 of the post and a socket aperture 36 that
extends through the body portion 32 of the socket 30. More
particularly, the pin member secures the upper end 22 of the post
20 to the post socket 30. The pin member is inserted through the
aligned apertures 26, 36 when the upper end 22 of the post is
positioned within the interior 34 of the body portion 32 of the
post socket 30. A retainer (not shown) known in the art secures the
pin member within the apertures 26, 36.
[0041] After the upper end 22 of the post 20 is received in the
interior 34 of the body portion 32, and the apertures 26, 36
aligned as described, the pin member is inserted through the
apertures 26, 36 and retained. The pin member is dimensioned such
that it fits snugly but slidingly in the passageway defined by the
apertures 26, 36 having the substantially same diameter, and is of
a length such that it extends through the body portion 32.
[0042] Accurate positioning of the vertical posts 20 is permitted
prior to inserting the pin member. Thus, the pin member when filled
through the apertures 26, 36, will set the posts 20 at a precise
position. The result is a precise positioning of the posts and
results in precise axial position of the pump's components.
[0043] As illustrated, the assembly 30 including the upper plate 31
and body portion 32 are defined by a first half 37 (as illustrated
first half 37 includes half 32A of the body portion 32 and half 31A
of the upper plate 31) and a second half 38 (as illustrated second
half 38 includes half 32B of the body portion 32 and half 31B of
the upper plate 31). In application, the assembly 30 can be
separated or opened (not shown) for inserting or removing the upper
end 22 of the posts 20, or in the closed position as shown in FIG.
6 for retaining the upper end 22 of the posts 20 as described.
[0044] In application, the upper plate of the first half 37 is
appropriately attached to the pump's motor mounting plate with
bolts (not shown) for example through apertures 39A. The upper end
of the post is then positioned with the interior 34 of the body
portion of the first half. The pin member can then be partially
inserted through the socket aperture in the first half 37 and
partially through the aperture 26 of the post. The second half 38
of the body portion is now positioned with the upper end of the
post such that the pin member can pass through the socket aperture
of the second half 38 and retained. The upper plate of the second
half 38 can then be appropriately attached to the pump's motor
mounting plate with bolts (not shown) for example through apertures
39B.
[0045] As should be understood, once the first and second halves
37,38 are positioned as described with upper end 22 retained with
pin member as disclosed, and the halves 37,38 are attached to the
motor mounting plate as described, the halves 37, 38 are
effectively joined with one another with the upper end 22 properly
aligned and affixed therein.
[0046] The assembly of the upper end 22 of the post 20 to the post
socket 30 as described illustrates an embodiment of a cement-less
pump joint which is an objective of the present invention.
Therefore a replacement post identical to posts 20 may be provided
without the need to dig out a cement joint but instead can be more
easily removed and replaced.
[0047] This coupling configuration between the upper end 22 of the
posts 20 and the post socket 30 provides very tight tolerances such
that the joint connection as described does not require other jigs
or equipment in order to align the pump during assembly and
installation.
[0048] It should be appreciated that according to the post mounting
assembly and method as described, the posts 20 can be mounted to
the base member 10 and the post socket 30 without requiring cement.
As a result, disassembling the pump becomes much less difficult.
Further, the present invention provides a pump and assembly system
which tends to self-align the pump during the assembly process.
[0049] As shown in FIG. 3, the post 20 may further include a first
groove 21A and a second groove 21B that each horizontally extend
around a mid-section designated as "MS" of the posts 20, with the
first groove 21A being just below an upper point P1 of the
mid-section MS, and the second groove 21B being just above point P2
of the mid-section MS. It should be understood that the mid-section
MS of the posts 20 represents an area on the posts that commonly
corrodes and breaks due to use.
[0050] The posts 20 may further include a protective sleeve 23 or
wrap for holding and protecting the mid-section MS of the posts 20.
More particularly, the sleeve is a protective sleeve that is
configured for providing protection, e.g., to slow down the
corrosion and erosion process that naturally occurs due to
extending submersion in the molten metal.
[0051] In the preferred embodiment, the protective sleeve 23 is in
surrounding relationship to the mid-section MS of the posts 20 as
shown, e.g., substantially from point P1 approximately above the
first groove 21A towards a point P2 approximately below the second
groove 21B. The sleeve 23 may extend a slightly greater or lesser
distance than the illustrated and described distance from P1 to
P2.
[0052] The purpose of the sleeve 23 is to separate the molten metal
from the mid-section MS of the posts 20 during application. By
limiting or lessening the extent of communication between the
molten metal and the mid-section of the posts 20, the Applicant has
found the extent and speed of corrosion is minimized during
use.
[0053] During manufacture, a fill composition (not shown) for the
protective sleeve 23 is poured into a mold between the sides of the
mold and the mid-section MS of each post 20. The fill composition
intersperses around the mid-section MS and forms a wall surrounding
the post 20. As should be understood, the fill composition further
fills the grooves 21A, 21B during the pouring process. The term
"pour" is used for the introduction of the fill composition into
the mold, and is intended to encompass any method of introducing a
fill composition into the mold in a liquid or other fluent form. It
is important that the fill composition be fluent because otherwise,
the fill composition will not intersperse around that area defined
as the mid-section MS and the grooves 21A, 21B.
[0054] FIG. 7 shows an alternate embodiment of pouring the
protective sleeve 23' to the mid-section MS of the posts 20' as
described. In FIG. 7, post 20' includes at least one groove 21'
that vertically extends the approximate length of the mid-section
MS, where an upper end 21A' of the groove being just below an upper
point P1 of the mid-section MS, and the lower end of the groove
21B' being approximately adjacent or just above point P2 of the
mid-section MS. The sleeve 23' may extend a slightly greater or
lesser distance than the illustrated and described distance from P1
to P2.
[0055] FIG. 8 is a second alternative embodiment illustrating a
post 20'' having a plurality of vertically aligned notches 21''
with the upper most notch designated as 21A'' being just below an
upper point P1 of the mid-section MS, and the lower most notch
designated as 21B'' being just above point P2 of the mid-section
MS. As with the other described embodiments, the sleeve 23'' may
extend a slightly greater or lesser distance than the illustrated
and described distance from P1 to P2.
[0056] Although the description above contains many specificities,
these should not be construed as limiting the scope of the
invention but as merely providing illustrations of some of the
presently preferred embodiments of this invention. Thus the scope
of the invention should be determined by the appended claims in the
formal application and their legal equivalents, rather than by the
examples given.
* * * * *