U.S. patent application number 12/939479 was filed with the patent office on 2012-05-10 for turbine powered cleaning apparatus.
This patent application is currently assigned to WAFERTECH, LLC. Invention is credited to Guy Jacobson.
Application Number | 20120110779 12/939479 |
Document ID | / |
Family ID | 46018252 |
Filed Date | 2012-05-10 |
United States Patent
Application |
20120110779 |
Kind Code |
A1 |
Jacobson; Guy |
May 10, 2012 |
TURBINE POWERED CLEANING APPARATUS
Abstract
A rotary turbine cleaning device for cleaning semiconductor
fabrication equipment works in conjunction with a clean room vacuum
or other vacuum or other air pump. The fluid flow created by the
vacuum action causes the rotors of the turbine assembly to rotate,
thereby rotating the cleaning head. Attached to the cleaning head
are bristles or other cleaning media which may dislodge particles
from surfaces. The dislodged particles are drawn into the tube
through an opening at the end of the tube and the vacuum
action.
Inventors: |
Jacobson; Guy; (Camas,
WA) |
Assignee: |
WAFERTECH, LLC
Camas
WA
|
Family ID: |
46018252 |
Appl. No.: |
12/939479 |
Filed: |
November 4, 2010 |
Current U.S.
Class: |
15/387 ;
15/21.1 |
Current CPC
Class: |
A46B 2200/3013 20130101;
A46B 13/001 20130101; A46B 13/02 20130101; B08B 1/04 20130101; A46B
13/003 20130101; A46B 15/0053 20130101 |
Class at
Publication: |
15/387 ;
15/21.1 |
International
Class: |
A47L 5/10 20060101
A47L005/10; A46B 13/00 20060101 A46B013/00 |
Claims
1. A cleaning apparatus comprising: a tube having a first end
coupled to an air pump and a rotatable cleaning device disposed at
a second end, said rotatable cleaning device comprising: a turbine
with an axial shaft; a rotatable head coupled to said shaft at said
second end; and bristles extending from said rotatable head.
2. The cleaning apparatus as in claim 1, wherein said turbine
comprises a rotor assembly including said shaft and a plurality of
rotor blades.
3. The cleaning apparatus as in claim 1, wherein said air pump
comprises a vacuum and said turbine and said rotatable head are
removably coupled to said tube.
4. The cleaning apparatus as in claim 3, wherein said tube is a
flexible tube.
5. The cleaning apparatus as in claim 1, wherein said rotatable
head is removable and interchangeable with further rotatable heads
having different outer diameters than said rotatable head.
6. The cleaning apparatus as in claim 1, wherein a terminus of said
second end includes said shaft extending therethrough and an
annular opening surrounding said shaft.
7. The cleaning apparatus as in claim 1, wherein at least a segment
of said shaft is disposed within a sleeve fixedly coupled to said
tube and centrally located within said tube.
8. The cleaning apparatus as in claim 1, wherein at least a segment
of said shaft is disposed within a sleeve centrally located within
said tube, said sleeve coupled to said tube by a friction fitting
with ribs that contact an inner surface of said tube, said friction
fitting opposed on an outer surface of said tube by a flange formed
of a rigid material and which extends circumferentially around said
tube.
9. The cleaning apparatus as in claim 1, wherein said bristles
extend outwardly form said rotatable head, comprise a plurality of
axially spaced rows of bristles and include bristles formed of at
least two different materials.
10. The cleaning apparatus as in claim 1, wherein said first end is
coupled to said air pump by way of a vacuum hose interposed
therebetween.
11. The cleaning apparatus as in claim 1, further comprising
laminar flow vanes disposed within said tube and downstream from
said turbine.
12. The cleaning apparatus as in claim 1, further comprising a
lumen disposed within or adjacent a wall of said tube and coupled
to a fluid delivery source, said lumen terminating at said second
end and capable of dispensing a cleaning fluid at said second
end.
13. The cleaning apparatus as in claim 1, wherein said air pump
comprises a clean room vacuum and delivers an air flow ranging from
about 100-250 cubic feet per minute.
14. The cleaning apparatus as in claim 1, further comprising a
filter disposed between said rotatable head and said turbine.
15. A vacuum powered brush comprising: a vacuum system; a vacuum
hose having a first end coupled to said vacuum system; a rotatable
brush disposed at a second end of said vacuum hose, said rotatable
brush comprising: a turbine with an axial shaft and a plurality of
rotor blades disposed within said hose; and a rotatable brush head
disposed at said second end and coupled to said shaft.
16. The vacuum powered brush as in claim 15, wherein at least a
segment of said shaft is disposed within a sleeve coupled to said
tube and centrally located within said tube, and said bristles are
formed of nylon.
17. The vacuum powered brush as in claim 15, further comprising
laminar flow vanes disposed within said tube and downstream from
said turbine, wherein said bristles comprise a plurality of axially
spaced rows of said bristles and said bristles include bristles
formed of at least two different materials.
18. The vacuum powered brush as in claim 15, wherein a diameter of
said rotatable brush head is different than an outer diameter of
said tube and said rotatable brush head is interchangeable with
further rotatable brush heads having different diameters.
19. The vacuum powered brush as in claim 15, wherein a terminus of
said second end includes said shaft extending therethrough and an
annular opening surrounding said shaft and further comprising
laminar flow vanes disposed within said tube and downstream from
said turbine.
20. The vacuum powered brush as in claim 15, further comprising a
lumen disposed within or adjacent a wall of said tube and coupled
to a fluid delivery source, said lumen terminating at said second
end and capable of dispensing a cleaning fluid at said second
end.
21. A cleaning apparatus comprising: a tube having a first end
coupled directly or indirectly to an air pump and a rotatable
cleaning device disposed at a second end thereof, said rotatable
cleaning device comprising: a turbine with an axial shaft that
protrudes from said second end; a head fixedly coupled to said
shaft at said second end; and a cleaning member coupled to and
extending peripherally from said head, said cleaning member formed
of a cleaning material comprising at least one of a scouring pad
material formed of intertwined mesh and a compressible porous
material.
22. The cleaning apparatus as in claim 21, wherein said cleaning
member comprises a plurality of discrete portions said cleaning
material.
Description
TECHNICAL FIELD
[0001] The invention relates, most generally, to a vacuum powered
turbine cleaning device used to remove particles from semiconductor
manufacturing tools.
BACKGROUND
[0002] The semiconductor manufacturing industry utilizes various
types of manufacturing or processing equipment, also known as
processing tools, to fabricate advanced semiconductor integrated
circuit devices and other devices that are highly integrated. These
highly integrated devices are formed to very tight design
tolerances and include increasingly smaller feature sizes. As
feature sizes continue to shrink further within the sub-micron
range, the devices are more susceptible to damage due to particle
contamination. Particle contamination therefore becomes an
increasingly serious problem as even the smallest particles and
very low particle densities must be controlled because device
functionality can be destroyed by even one small particle. The
manufacturing tools used to fabricate semiconductor devices must
therefore be maintained at high levels of cleanliness. It is
therefore of critical importance to prevent the accumulation of
particles in such manufacturing tools and to completely remove any
and all particles from such manufacturing tools when cleaning or
other maintenance procedures are carried out upon the tool.
[0003] Many processing tools are available and used to coat
semiconductor substrates with photoresist or other photosensitive
materials. Much of the foreign material introduced into the
processing, i.e. coating, chamber is unused and must be removed
from the processing environment. This includes the photoresist
materials that are spun off the edges of semiconductor substrates
that rotate at high speeds. The processing tools include outlet and
exhaust ports and tubes through which the unused material is
expelled. A buildup of residue of the unused coating material can
accumulate in these ports and tubes. The buildup in the tubes can
clog the tubes, block the ports or restrict exhaust flow. Moreover,
the residue can become a major source of particle contamination,
especially as it dries and delaminates. Defects that commonly occur
on substrate surfaces result from particles that originate from
exhaust ducts. As a result, these ports and tubes are cleaned
regularly. When such exhaust systems are cleaned, they must
therefore be thoroughly and completely cleaned so as to remove all
particles and prevent the particles from becoming disgorged back
into the main processing, i.e. coating, chamber of the processing
system where they can contaminate devices and ruin device
functionality. The cleaning process itself must be carried out in a
manner that does not generate particles.
[0004] Conventional cleaning methods are carried out using brushes
such as bottle-brushes, i.e. long, cylindrical brushes with brittle
bristles designed to extend into and clean bottles. These
bottle-brushes are inserted into the exhaust ports and used to
dislodge and remove particles. When this occurs, however, many
particles that become generated or dislodged from the residue
formed in the exhaust port, are spread throughout the coating
chamber and eventually find their way onto substrate surfaces. This
re-introduction of particles back into the coating, i.e. processing
chamber during the cleaning procedure, must be eliminated.
BRIEF DESCRIPTION OF THE DRAWING
[0005] The disclosure is best understood from the following
detailed description when read in conjunction with the accompanying
drawing. It is emphasized that, according to common practice, the
various features of the drawing are not necessarily to scale. On
the contrary, the dimensions of the various features are
arbitrarily expanded or reduced for clarity. Like numerals denote
like features throughout the specification and drawing.
[0006] FIG. 1 is a side view in partial cross-section, illustrating
an exemplary turbine-powered cleaning apparatus according to the
disclosure;
[0007] FIG. 2A is a side view in partial cross-section,
illustrating a further exemplary turbine-powered cleaning apparatus
according to the disclosure;
[0008] FIGS. 2B and 2C show a friction fitting used in the
embodiment of FIG. 2A;
[0009] FIGS. 2D and 2E show another embodiment of a friction
fitting that includes a filter;
[0010] FIG. 3 is a side view illustrating a further exemplary
turbine-powered cleaning apparatus being used in a cleaning
operation;
[0011] FIG. 4 is a side view illustrating another exemplary
embodiment of a turbine-powered cleaning apparatus according to the
disclosure; and
[0012] FIG. 5 is a side view showing yet another exemplary
embodiment of a turbine-powered cleaning apparatus according to the
disclosure.
DETAILED DESCRIPTION
[0013] The disclosure provides a brush or other cleaning member or
device that is turbine-powered. A multi-rotor turbine assembly is
affixed within a tube or hose that is coupled to an air pump such
as a vacuum system. The fluid flow causes the rotors and thus the
shaft of the turbine assembly to rotate. The head of the brush or
other cleaning member is affixed to the shaft and rotates along
with the shaft and the bristles or other cleaning media extend
outwardly due to centrifugal force, dislodging particles which are
sucked into the tube through an annular opening at the end of the
tube due to the vacuum action.
[0014] FIG. 1 is a side view in partial cross-section illustrating
an exemplary turbine-powered cleaning apparatus according to the
disclosure. The turbine-powered cleaning member embodiment
illustrated in FIG. 1 is turbine-powered brush 10. Turbine-powered
brush 10 includes tube 12, head 14 and turbine assembly 16 within
tube 12. Tube 12 may be a vacuum hose or other suitable tube such
as a Teflon tube but tube 12 may be formed of various other
suitable materials in other exemplary embodiments. Tube 12 may be
flexible or rigid. Tube 12 includes inner surface 20, outer surface
22 and diameter 24. Tube 12 is shown in a cut-away cross section,
with other components including the components inside tube 12 and
the head portion, shown in side view.
[0015] In one exemplary embodiment, diameter 24 of tube 12 may be 1
inch, but in other exemplary embodiments, diameter 24 may range
from 0.25 inches to 4 or 5 inches. Tube 12 includes first end 28
and a second end coupled to a vacuum source, air pump, or other
source that causes fluid flow as indicated by fluid flow arrow 32
at vacuum source end 30. In one exemplary embodiment, tube 12 may
be several feet long and vacuum source end 30 is coupled to a
vacuum source. In one exemplary embodiment, vacuum source end 30
may represent that tube 12 includes a length of about 8 inches to
about 24 inches and may be attachable, using any of various
mechanical means such as threads, to a conventional vacuum hose
such as a clean room vacuum hose. The vacuum source may be a clean
room vacuum system such as an exemplary clean room vacuum system
manufactured by Nilfisk CFM of Malvern, Pa. but other suitable
clean room or other vacuum systems may be used as well.
[0016] Various air pumps or vacuum systems may be used to produce
fluid flow which may advantageously be air flow such as flow of the
clean room air. Various suitable clean room vacuum systems or other
commercially available vacuum sources may be used. Fluid flow using
commercially available vacuum sources may range from about 50-300
cubic feet per minute, but other fluid flow values may be attained
using other vacuum sources and may be used in other exemplary
embodiments.
[0017] Turbine assembly 16 includes a plurality of rotors 36 that
cause shaft 38 to rotate when rotors 36 rotate due to fluid flow as
indicated by fluid flow arrow 32. Fluid flow 32 created by the
vacuum source can be used to cause the rotary motion of rotors 36
and shaft 38 at speeds of 15,000 RPM or greater in one exemplary
embodiment. Rotors 36 may be formed of thin-gauge anodized steel or
other suitable rigid material such as other metals and the number
of illustrated rotors--five--is intended to be exemplary only.
Shaft 38 may be formed of steel or other metals or various other
suitable non-deformable and rigid materials in various exemplary
embodiments.
[0018] Shaft 38 extends through support sleeve 40 and within chuck
42 and is coupled to head 14 such that, when shaft 38 rotates, head
14 also rotates. Support sleeve 40 is centrally and fixedly coupled
to tube 12 by means of mounting screws 44 and alignment screws 46
in the exemplary embodiment, but other suitable coupling means may
be used in other exemplary embodiments. In various other exemplary
embodiments, such as one that will be shown in FIG. 2, turbine
powered brush 10 may be removable from tube 12 and may be secured
in place within tube 12, using various friction-fitting means.
Again referring to FIG. 1, according to the illustrated embodiment,
mounting screws 40 are received within openings in tube 12. Support
sleeve 40 may be formed of a poly-carbonate material or Lexan.RTM.
or other suitable materials. Shaft 38 rotates freely within support
sleeve 40. Chuck 42 secures shaft 38 to head 14. Chuck 42 extends
into head 14 and surrounds shaft 38. Shaft 38 and chuck 42 protrude
from tube 12 at terminus 50 of first end 28 which includes annular
opening 52. Annular opening 52 surrounding the head 14/chuck 42
assembly serves as an air intake when the air pump or vacuum source
is turned on to create fluid flow 32. Additional support for shaft
38 may be supplied by bearing race 56 which is in contact with and
combines with thrust bearing 58 which contains ball bearings.
Thrust bearing 58 is coupled to and rotates along with chuck 42 due
to the ball bearings which facilitate low friction movement and
load bearing capabilities. Bearing race 56 and thrust bearing 58
may be used in conjunction with one or more washers to prevent
slippage but these components are intended to be exemplary only.
Various other thrust bearings or other mechanisms capable of
performing the same function may be used in other exemplary
embodiments. Chuck 42 and thrust bearing 58 may be formed of an
alloy such as brass but other metals and alloys may be used in
other exemplary embodiments.
[0019] Head 14 may be formed of Teflon or other suitable
non-corrosive materials. Bristles 62 may be formed of stainless
steel, Kevlar, nylon or other similar materials, or other suitable
materials. In the illustrated embodiment, it can be seen that there
are two axially spaced rows of bristles 62. According to one
exemplary embodiment, bristles 62 may include bristles formed of
two or more different materials such as the aforementioned
materials. In one exemplary embodiment, one of the rows of bristles
62 may be formed of one material and another of the rows of
bristles 62 may be formed of a further material. Bristles 62 extend
outwardly due to centrifugal force when shaft 38 and head 14
rotate. Bristles 62 may be secured to head 14 by an o-ring 66
received within a corresponding channel that extends around the
periphery of head 14. Other bristle arrangements may be used in
other exemplary embodiments. According to one exemplary embodiment,
only one row of bristles that extends peripherally around head 14
to form a row that is substantially orthogonal to shaft 38, may be
used and may include bristles formed of two or more different
materials. Balancing set screws 64 or other suitable means may be
used to properly balance head 14.
[0020] Tube 12 may be rigid or flexible according to various
exemplary embodiments and may be stabilized by flanges 68 that
extend circumferentially around tube 12, contacting outer surface
22. Wall fenders 70 may be o-rings or other pliable materials that
extend around flanges 68 and may be received within a corresponding
channel 72 of flange 68. Wall fenders 70 and flanges 68 are also
shown in cut-away cross-sectional view. Laminar flow vanes 76 may
be included within tube 12 to stabilize tube 12 and guide fluid
flow 32. Laminar flow vanes 76 may be formed of poly-carbonate,
Lexan.RTM. or other suitable materials and may advantageously
maintain fluid flow in a laminar state.
[0021] FIG. 2A is a side view showing another exemplary embodiment
of a turbine-powered cleaning brush. In the embodiment in FIG. 2A,
also shown with tube 12, flanges 68 and wall fenders 70 shown in
cutaway cross section, winged friction fitting member 75 is secured
within tube 12. Winged friction fitting member 75 is shown in front
and side views in FIG. 2B and FIG. 2C, respectively, as well.
Winged friction fitting member 75 includes centrally disposed
support sleeve 40 that receives shaft 38 and also ribs 77 that
extend from support sleeve 40 and abut inner surface 20 of tube 12.
Winged friction fitting member 75 is sized in conjunction with tube
12 to fit snugly within tube 12. End faces 81 of ribs 77 contact
inner surfaces 20. According to one exemplary embodiment, winged
friction fitting member 75 may work in conjunction with flange 68
and wall fenders 70 to form a friction fitting. Flange 68 may be
formed of metal or other suitable rigid materials and may fit
snugly on an opposed outer surface 22 of tube 12. According to one
exemplary embodiment, ribs 77 may be formed of metals, plastics,
other polymers or other suitable rigid materials. According to
other exemplary embodiments, ribs 77 may be spring loaded members
that may be compressible and urge an outward force to provide
contact to inner surfaces 20.
[0022] FIGS. 2D and 2E illustrate another exemplary embodiment of
winged friction fitting member 75 in front and side views,
respectively. According to this illustrated embodiment, winged
friction fitting member 75 includes filter 79. Filter 79 may be
used to trap large particles upstream from turbine assembly 16. The
embodiment in which filter 79 is a screen, is intended to be
exemplary only and in another exemplary embodiments, other filters
types may be used. In addition to the illustrated embodiment in
which filter 79 is integrated within winged friction fitting member
75, filter 79 may be positioned in various other locations within
tube 12, in other exemplary embodiments.
[0023] FIG. 3 shows turbo-powered brush 10 being used in a cleaning
operation. In the illustrated embodiment, the maximum diameter of
head 14 is less than diameter 24 of tube 12 but the diameter of
head 14 plus bristles 62 and 84 extending outwardly, is greater
than diameter 24. According to various exemplary embodiments, head
14 may be removable and interchangeable with other heads having
different diameters. As such, the maximum diameter of head 14 may
be less than, equal to or greater than diameter 24 of tube 12.
Semiconductor processing tool 90 includes exhaust duct 80 which
extends from processing chamber 94. Exhaust duct 80 includes
residue 82 adhering to its inner surfaces. Semiconductor processing
tool 90 may be a coating tool in one exemplary embodiment in which
residue 82 may be unused photoresist or ARC (anti-reflective
coating) or any of various other coating materials applied to a
substrate during semiconductor fabrication operation such as a
coating operation. Turbine-powered brush 10 may be used to clean
various other ducts, exhaust ports and outlet tubes of other
semiconductor manufacturing equipment in other exemplary
embodiments.
[0024] Fluid flow is indicated by fluid flow arrow 32 and is a
result of tube 12 being coupled to a vacuum source, air pump or
other fluid flow source. According to the illustrated embodiment,
head 14 includes bristles 62 and further bristles 84, either or
both of which may be formed of stainless steel, nylon, Kevlar.RTM.,
combinations thereof, or other suitable materials. Centrifugal
force causes each of the aforementioned bristles to extend
outwardly and rotate, dislodging particles 88 from residue 80
within duct 80. Fluid flow 32 causes the turbine (not shown in FIG.
3) to cause head 14 and bristles 66, 84 to rotate and also creates
air flow as indicated by air flow arrows 92. Air and particles 88
enter tube 12 at terminus 50 through annular opening 52. With
liberated particles 88 sucked into tube 12 as such, the particles
do not reenter processing chamber 94 of semiconductor processing
tool 90 and therefore do not create particle contamination.
[0025] FIG. 4 shows another exemplary embodiment of turbo-powered
brush 10 with bristles 62 and further bristles 84 extending from
head 14. Lumen 96 is affixed to outer surface 22 of tube 12 and may
be secured in place by of flanges 68 and wall fenders 70. In other
exemplary embodiments, not illustrated, the walls of tube 12 may be
thick enough to accommodate a lumen therein. According to either
exemplary embodiments, the lumen is attached to a fluid source at
end 98 and is capable of dispensing the fluid at outlet port 100.
The fluid may be acetone, isopropyl alcohol, or other suitable
cleaning fluids or solvents that are useful in cleaning surfaces
and/or dissolving materials in semiconductor processing tools, or
both. Cleaning fluid 102 may be dispensed as a spray or as a mist
and may exit lumen 96 as cleaning fluid 102 at outlet port 100. The
flow of cleaning fluid 102 is controlled to work in conjunction
with the cleaning action of bristles 62, 84 and also in conjunction
with the vacuum provided due to the vacuum or other air pump
affixed to tube 12. In this manner, cleaning fluid 102 dispensed at
outlet port 100 may be sucked back into tube 12 due to the vacuum
force after moistening residue or other materials being removed by
turbo-powered brush 10.
[0026] FIG. 5 shows another exemplary cleaning device according to
the disclosure. Turbo powered cleaning apparatus 110 includes
several of the previously described features. In the illustrated
exemplary embodiment of FIG. 5, affixed to head 14 is cleaning
member 112. In one exemplary embodiment, cleaning member 112
consists of a plurality of discrete cleaning member sections that
extend radially outward from head 14 and shaft 38 and are
positioned generally linearly along a single row that extends
substantially orthogonal to shaft 38 and peripherally around head
14. According to one exemplary embodiment, each of a plurality of
discrete sections of cleaning member 112 may be formed of a sponge
material or other compressible porous material. According to other
exemplary embodiments, each of a plurality of discrete sections of
cleaning member 112 may be formed of intertwined mesh such as a
scouring pad. Other materials may be used in other exemplary
embodiments and cleaning member 112 may take on other shapes
besides the illustrated embodiment of discrete portions. According
to another exemplary embodiment, cleaning member 112 may be a
member that extends continuously around head 14 instead of a
plurality of discrete sections.
[0027] According to one aspect of the disclosure, a cleaning
apparatus is provided. The cleaning apparatus comprises a tube
having a first end coupled to an air pump and a rotatable cleaning
device disposed at a second end, the rotatable cleaning device
including a turbine with an axial shaft protruding from the second
end, a rotatable head coupled to the shaft at the second end, and,
bristles extending outwardly from the rotatable head.
[0028] According to another aspect, the disclosure provides a
vacuum-powered brush. The vacuum-powered brush comprises a vacuum
system and a vacuum hose having a first end coupled to the vacuum
system. The vacuum-powered brush further comprises a rotatable
brush disposed at a second end of the vacuum tube, the rotatable
brush including a turbine with an axial shaft that protrudes from
the second end of the tube and a plurality of rotor blades disposed
within the hose and a rotatable brush head coupled to the shaft at
the second end.
[0029] According to another aspect, the disclosure provides a
cleaning apparatus comprising a tube having a first end coupled to
an air pump and a rotatable cleaning device disposed at a second
end. The rotatable cleaning device comprises a turbine with an
axial shaft protruding from the second end, a head fixedly coupled
to the shaft at the second end and a cleaning member coupled to and
extending peripherally from the head. The cleaning member includes
at least one of a scouring pad material formed of intertwined mesh
and a compressible porous material.
[0030] The preceding merely illustrates the principles of the
disclosure. It will thus be appreciated that those skilled in the
art will be able to devise various arrangements which, although not
explicitly described or shown herein, embody the principles of the
disclosure and are included within its spirit and scope. For
example, in addition to the embodiments recited, the disclosure
also covers various other combinations of the disclosed features.
Each of the following claims of this document constitutes a
separate embodiment, and embodiments that combine different claims
and/or different embodiments are within the scope of the disclosure
and will be apparent to those of ordinary skill in the art after
reviewing this document.
[0031] Furthermore, all examples and conditional language recited
herein are principally intended expressly to be only for
pedagogical purposes and to aid the reader in understanding the
principles of the disclosure and the concepts contributed to
furthering the art, and are to be construed as being without
limitation to such specifically recited examples and conditions.
Moreover, all statements herein reciting principles, aspects, and
embodiments, as well as specific examples thereof, are intended to
encompass both structural and functional equivalents thereof.
Additionally, it is intended that such equivalents include both
currently known equivalents and equivalents developed in the
future, i.e., any elements developed that perform the same
function, regardless of structure.
[0032] This description of the exemplary embodiments is intended to
be read in connection with the figures of the accompanying drawing,
which are to be considered part of the entire written description.
In the description, relative terms such as "lower," "upper,"
"horizontal," "vertical," "above," "below," "up," "down," "top" and
"bottom" as well as derivatives thereof (e.g., "horizontally,"
"downwardly," "upwardly," etc.) should be construed to refer to the
orientation as then described or as shown in the drawing under
discussion. These relative terms are for convenience of description
and do not require that the apparatus be constructed or operated in
a particular orientation. Terms concerning attachments, coupling
and the like, such as "connected" and "interconnected," refer to a
relationship wherein structures are secured or attached to one
another either directly or indirectly through intervening
structures, as well as both movable or rigid attachments or
relationships, unless expressly described otherwise.
[0033] Although the disclosure has been described in terms of
exemplary embodiments, it is not limited thereto. Rather, the
appended claims should be construed broadly, to include other
variants and embodiments of the disclosure, which may be made by
those skilled in the art without departing from the scope and range
of equivalents.
* * * * *