U.S. patent application number 09/882902 was filed with the patent office on 2002-12-19 for modular stamped sight glass assembly.
Invention is credited to Kacik, Ralph, Kohler, Jurgen, Roskavich, Ronald.
Application Number | 20020189554 09/882902 |
Document ID | / |
Family ID | 25381572 |
Filed Date | 2002-12-19 |
United States Patent
Application |
20020189554 |
Kind Code |
A1 |
Kohler, Jurgen ; et
al. |
December 19, 2002 |
MODULAR STAMPED SIGHT GLASS ASSEMBLY
Abstract
A sight glass assembly for a water heater flame trap and a
method of making same is disclosed. A rectangular-shaped sight
glass frame casing being comprised of a thin metal plate further
comprising a rounded rectangular cut-out window and two metal tabs
on opposite sides of the casing acting as a retainer to hold the
planar transparent material of the sight window tight to the
rectangular-shaped gasket. The metal frame casing of the sight
glass assembly attaches to the exterior of the flame trap
compartment of the hot water heater by: (a) either inserting the
tabs, further comprising metal clips, into the gasket whereby they
expand, locking the metal frame casing in place; or in a second
embodiment (b) riveting the tabs, now in the shape of a flange,
directly to the hot water heater shell. The metal frame casing is
formed by a metal stamping procedure that allows for easier and
more economic manufacture of the sight glass retainer.
Inventors: |
Kohler, Jurgen; (Medina,
OH) ; Kacik, Ralph; (North Royalton, OH) ;
Roskavich, Ronald; (North Royalton, OH) |
Correspondence
Address: |
ARTER & HADDEN, LLP
1100 HUNTINGTON BUILDING
925 EUCLID AVENUE
CLEVELAND
OH
44115-1475
US
|
Family ID: |
25381572 |
Appl. No.: |
09/882902 |
Filed: |
June 15, 2001 |
Current U.S.
Class: |
122/13.01 ;
122/494; 122/497; 122/499 |
Current CPC
Class: |
F23M 11/042
20130101 |
Class at
Publication: |
122/13.01 ;
122/497; 122/499; 122/494 |
International
Class: |
F23M 005/08 |
Claims
1. A sight glass assembly comprising (a) a frame casing having a
front face, side walls, an upper wall, a lower wall, an opening in
the front face, and securment extensions which extend from at least
two of the side walls; (b) a piece of planar transparent material
having an outer perimeter dimensioned to fit within the walls of
the frame, and to span the opening in the front face, wherein the
walls extend over the edges of the transparent material; (c) a
generally planar gasket having an outer perimeter greater than an
outer perimeter of the casing, and an opening having a perimeter
less than the outer perimeter of the transparent material wherein
the securement extensions are configured to engage with a structure
having an opening generally aligned with the openings in the gasket
and the frame to provide a sight glass through the opening in the
structure.
2. The sight glass assembly of claim 1 wherein the walls of the
frame are oriented approximately ninety degrees relative to the
front face of the frame.
3. The sight glass assembly of claim 1 wherein the securement
extensions extend in generally the same plane as the corresponding
wall.
4. The sight glass assembly of claim 1 wherein the securement
extensions extend in a plane generally parallel to the front face
of the frame.
5. The sight glass assembly of claim 1 wherein the securement
extensions are spring to compressively engage about an opening in a
structure.
6. The sight glass assembly of claim 1 wherein at least one of the
securement extensions is configured to receive a fastener for
attaching the frame to a structure.
7. The sight glass assembly of claim 1 wherein the gasket has an
outer perimeter dimensioned to extend beyond an opening in a
structure.
8. The sight glass assembly of claim 1 wherein the walls of the
frame extend away from the face to an extent not greater than a
thickness of the transparent material.
9. The sight glass assembly of claim 1 wherein the securement
extensions extend through the gasket.
10. The sight glass assembly of claim 1 wherein the securement
extensions overlie peripheral portions of the gasket.
11. A modular sealed sight glass assembly adapted for attachment to
a wall section to provide a sealed view path, the assembly
comprising: a frame having a planar face wall and an opening in the
face wall defining a viewing port; framing walls extending
generally perpendicularly from a perimeter of the face wall, at
least one of the framing walls further comprising a securement
extension; a piece of transparent material dimensioned to fit
within the framing walls and against the face wall; a gasket having
an outer perimeter greater than the face wall of the frame, and an
internal opening having a perimeter less than a perimeter of the
piece of transparent material, the internal opening of the gasket
being generally aligned with the opening in the face wall, and the
gasket being positioned against the transparent material opposite
to the face wall of the frame.
12. The sight glass assembly of claim 11 wherein a perimeter of the
frame is generally rectangular.
13. The sight glass assembly of claim 11 wherein the framing walls
extend from the face wall to substantially cover edges of the
transparent material.
14. The sight glass assembly of claim 11 comprising a single
framing wall extending from each perimeter of the face wall.
15. The sight glass assembly of claim 11 comprising more than one
framing wall extending from a perimeter of the face wall.
16. The sight glass assembly of claim 11 wherein edges of the
framing walls contact the gasket, and wherein at least a portion of
the gasket extends beyond the framing walls.
17. The sight glass assembly of claim 11 wherein a securement
extension extends through the gasket.
18. The sight glass assembly of claim 11 wherein a securement
extension substantially overlies a portion of the gasket which
extends beyond the framing walls.
19. The sight glass assembly of claim 11 in combination with a wall
section of a chamber, wherein the wall section has an opening which
corresponds with the opening in the face wall.
20. A sight glass assembly in combination with a combustion
chamber, the combustion chamber having a shroud with at least one
wall and an opening through a cross-section of the shroud wall, a
sight glass frame having a face plate with an opening and perimeter
walls which extend perpendicularly from the face plate, a planar
transparent piece which fits within the perimeter walls of the
frame and against the face plate, and a gasket with an opening
which corresponds to the opening in the face plate and the opening
in the shroud wall and which extends at least partially beyond a
perimeter of the face plate, the gasket being positioned against
the shroud wall and about the opening in the shroud wall, and the
transparent material and face plate being positioned over the
gasket and attached to the shroud wall.
21. The sight glass assembly combination of claim 20 in further
combination with a water tank wherein the combustion chamber is a
heat source for the water tank.
22. The sight glass assembly combination of claim 20 wherein the
sight glass frame is formed as a metal stamping.
23. The sight glass assembly combination of 20 wherein the sight
glass assembly is attached to the shroud wall by a fastener.
24. The sight glass assembly combination of claim 20 wherein the
sight glass assembly is attached to the shroud wall by a securement
extension which extends from a perimeter wall of the sight glass
frame.
25. The sight glass assembly combination of claim 20 wherein the
gasket is in a partially compressed state between the transparent
piece and the shroud wall.
26. The sight glass assembly combination of claim 20 wherein the
securement extensions extend through the shroud wall.
27. The sight glass assembly combination of claim 20 wherein the
securement extensions extend laterally from the perimeter walls of
the sight glass frame.
28. The sight glass assembly combination of claim 20 wherein the
perimeter walls of the sight glass frame extend away from the face
plate a distance less than a thickness dimension of the transparent
piece.
29. The sight glass assembly combination of claim 20 in combination
with a water heater, wherein the combustion chamber is located
beneath a water tank of the water heater.
30. The sight glass assembly combination of claim 20 wherein the
sight glass assembly is generally aligned with a combustion source
within the combustion chamber.
31. A flame trap equipped water heater having: a water reservoir;
an open flame source positioned proximate to the water reservoir
and housed within a flame trap compartment; the flame trap
compartment at least partially enclosed by a cover panel attached
to an exterior of the water heater, the cover panel having an
opening; a sight glass assembly attached to the cover panel about
the opening, the sight glass assembly having a face plate with an
opening which corresponds to the opening in the cover panel and
which is configured to position and secure a transparent piece over
the corresponding openings and to position and secure a gasket
between the transparent piece and a periphery of the opening in the
cover panel about the corresponding openings.
Description
FIELD OF THE INVENTION
[0001] The present invention pertains generally to sight glass
assemblies and, more particularly, to low cost modular sight glass
assemblies which are suitable for installation where vapor control
is required.
BACKGROUND OF THE INVENTION
[0002] Sight glass assemblies are widely used in many different
types of machines and vessels to observe internal workings. For
many installations, the sight glass window and the surrounding
framework must be appropriately engineered to withstand and contain
the internal environment. This can require a complex assembly of
parts, including bezels with multiple interfacing components, and
glass or transparent layers with highly engineered interfaces
between the glass and the bezel housing. For example, U.S. Pat.
Nos. 3,941,460; 3,977,251; 4,169,309; 4,182,179; 4,206,537;
4,436,375; 4,468,095; 5,210,658 and 5,763,776 all disclose complex
sight glass assemblies with heavy machined frame structures secured
about a glass piece and attached to a vessel in high pressure or
corrosive environments. These types of assemblies are of course
costly to produce, assemble and install, and are therefore
generally found on specialized industrial equipment, such as
chemical and food processing equipment. Because it is critical in
these applications to maintain the view path for inspection of
internal conditions, these types of highly engineered sight glass
assemblies are justified.
[0003] In other applications, the environment may be less hostile
or corrosive, allowing for a less complex construction. For
example, U.S. Pat. No. 5,735,168 discloses a sight glass assembly
for use on an animal feeder that does not require access to the
interior, but which contains multiple layers and at least four
fasteners for attachment to a wall. In other words, the design and
construction of a sight glass assembly is highly dependent upon the
installation environment.
[0004] The development of new type of water heater has created a
new application for an effective yet economical sight glass
assembly. Until recently water heaters have been manufactured with
the pilot light and burner contained in a open air shroud
underneath the water tank. This allows flammable vapors to easily
come into contact with the open flame of the pilot or burner and
cause an uncontrolled explosion or fire. To prevent this, a
vapor-controlled flame chamber has been developed for use with a
water heater. As described for example by U.S. Pat. No. 6,116,195,
an enclosed flame trap assembly for water heaters has an air inlet
in the form of a plate with a plurality of ports, each port being
sized and shaped to cause air and extraneous fumes to pass through
the ports at a velocity higher than the flame velocity of the
extraneous fumes, to confine ignition and combustion of extraneous
fumes within the combustion chamber. More specifically, the patent
describes the exact design of openings or "ports" in the air inlet
which inhibit flames from ignition of extraneous fumes from exiting
the flame trap assembly. This greatly reduces the risk of
accidental home fires caused by flammable vapors coming into
contact with the flame of the water heater burner. This innovation
has been heralded as a significant safety improvement in water
heater home safety by the U.S. Consumer Product Safety Commission.
The flame trap assembly however, is otherwise substantially sealed,
which interferes with inspection of the pilot and burner flame.
[0005] Thus the need is created to incorporate a sight glass into
this type of flame trap assembly to enable visual inspection of the
burner assembly and operation, particularly with respect to gas
flow in the absence of a flame, which could lead to gas poisoning
or uncontrolled explosion.
[0006] This type of sight glass is primarily subject to heat,
rather than pressure. Otherwise, the primary performance criteria
(in addition to providing the view path) is to maintain the vapor
control integrity of the flame trap assembly. Therefore, a
principal objective of the invention is to provide a sight glass
assembly which maintains the vapor control function of the flame
trap assembly but which is economical for mass production in flame
trap equipped water heaters.
SUMMARY OF THE INVENTION
[0007] The present invention provides novel solutions to these and
other aspects of water heater flame control systems, by providing a
modular sight glass assembly frame that does not require custom
fasteners or fittings, but still creates a sufficient seal and
window area. The design is also economical to produce and assemble.
In one embodiment the securing tabs allow for the sight glass
assembly to be easily snapped into position on the exterior of the
flame trap compartment. In another, the sight glass assembly is
secured by two rivet-like fasteners, allowing for a more flexible
placement and less cutout area in the flame trap assembly
compartment wall.
[0008] In accordance with one general aspect of the invention,
there is provided a sight glass assembly with frame casing having a
front face, side walls, an upper wall, a lower wall, an opening in
the front face, and securment extensions which extend from at least
two of the side walls; a piece of planar transparent material
having an outer perimeter dimensioned to fit within the walls of
the frame, and to span the opening in the front face, wherein the
walls extend over the edges of the transparent material; a
generally planar gasket having an outer perimeter greater than an
outer perimeter of the casing, and an opening having a perimeter
less than the outer perimeter of the transparent material wherein
the securement extensions are configured to engage with a structure
having an opening generally aligned with the openings in the gasket
and the frame to provide a sight glass through the opening in the
structure.
[0009] In accordance with another general aspect of the invention,
there is provided a modular sealed sight glass assembly adapted for
attachment to a wall section to provide a sealed view path,
including a frame having a planar face wall and an opening in the
face wall defining a viewing port; framing walls extending
generally perpendicularly from a perimeter of the face wall, at
least one of the framing walls further comprising a securement
extension; a piece of transparent material dimensioned to fit
within the framing walls and against the face wall; a gasket having
an outer perimeter greater than the face wall of the frame, and an
internal opening having a perimeter less than a perimeter of the
piece of transparent material, the internal opening of the gasket
being generally aligned with the opening in the face wall, and the
gasket being positioned against the transparent material opposite
to the face wall of the frame.
[0010] And in accordance with another aspect of the invention,
there is provided a sight glass assembly in combination with a
combustion chamber, the combustion chamber having a shroud with at
least one wall and an opening through a cross-section of the shroud
wall, a sight glass frame having a face plate with an opening and
perimeter walls which extend perpendicularly from the face plate, a
planar transparent piece which fits within the perimeter walls of
the frame and against the face plate, and a gasket with an opening
which corresponds to the opening in the face plate and the opening
in the shroud wall and which extends at least partially beyond a
perimeter of the face plate, the gasket being positioned against
the shroud wall and about the opening in the shroud wall, and the
transparent material and face plate being positioned over the
gasket and attached to the shroud wall.
[0011] These and other aspects of the invention are herein
described with reference to the accompanying Figures representative
of several of many possible embodiments of the principles and
concepts of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1 is an isometric view of the sight glass assembly
installed in a generic water heater.
[0013] FIG. 2 is an exploded isometric view of the elements of the
first embodiment of the sight glass assembly.
[0014] FIG. 3 is an exploded side view of the first embodiment of
the sight glass assembly.
[0015] FIG. 4 is a cross-sectional view of the first embodiment of
the sight glass assembly as installed in a generic water
heater.
[0016] FIG. 5 is a cross-sectional view of the second embodiment of
the sight glass assembly as installed in a generic water
heater.
[0017] FIG. 5A is an exploded side view of the elements in the
second embodiment of the sight glass assembly with a modified side
wall design.
[0018] FIG. 6 is an exploded isometric view of the second
embodiment of the sight glass assembly.
DETAILED DESCRIPTION OF PREFERRED AND ALTERNATE EMBODIMENTS
[0019] A first embodiment of the sight glass assembly 10 is shown
in FIGS. 2 through 4. The sight glass assembly 10 is attached to
the cover panel 8 of the flame trap compartment 6 of a water heater
4, wherein the flame trap assembly compartment is located generally
below the water tank. The cover panel 8 or an area thereof such as
recessed area 9, may be flat, planar, and slightly recessed from
the curved cylindrical exterior wall of the water heater 4, or of
the same curvature of the cylindrical exterior wall. The flame trap
compartment 6 is also generally referred to herein as a "shroud",
and the wall of the flame trap compartment or the cover panel as a
"shroud wall". The sight glass assembly 10 comprises a metal frame
or casing 12, a piece of planar transparent material 18, e.g., made
of glass or plastic, and a generally planar flexible gasket 20. The
frame 12 has a top wall 14, a bottom wall 15, and two opposed side
walls 16, formed generally as angled flanges from a face 13 of the
frame. Walls 14, 15 and 16 are also referred to herein as
"perimeter walls". Face 13 is also referred to as a "face plate".
The top wall 14 and bottom wall 15 are formed by two rounded tabs
or flap-like elements bent generally 90.degree. from the face 13 of
the frame 12. Preferably, the extent of the walls 14 and 15 from
face 13 is less than or equal to, and not greater than, the
thickness of the planar transparent material 18.
[0020] The transparent planar material 18 may be a type of glass,
colored or clear, so long as it allows the status of the flame to
be determined. The gasket 20, 33 material may be made of a flexible
polymer or rubber that will sufficiently create the necessary seal
to isolate the inner flame trap assembly from exterior
elements.
[0021] In this embodiment, each side wall 16 has a securing tab 17
or "securement extension" which extends from an edge of the wall 16
opposite face 13. Tabs 17 are configured to extend through the
slots 19 in the flexible gasket 20 and into the cover panel 8 of
the flame trap compartment 6, such as by engaging a perimeter
portion of opening 23 in cover panel 8, or through a similar
opening in a wall section of any other installation or
application.
[0022] Frame 12 has an opening 11 formed in the front face 13,
generally equal in size and preferably smaller than a corresponding
opening 21 in the flexible gasket 20. The planar transparent
material 18 is dimensioned to fit within the four walls (14, 15 and
16) of the frame 12, and to completely cover the gasket opening 21,
as shown in the assembled state in cross-section in FIG. 4.
[0023] The frame 12 is preferably a single piece stamping made of
appropriate steel, such as for example Martinsite M130, in a
progressive or sequential die cutting and stamping operation,
wherein the frame is die cut as a single piece, and each of the
perimeter walls and tabs formed by conventional stamping methods.
This enables high speed production of frames to close finished
tolerances, with the strength required to securely hold the
assembly in place when installed, and to establish the desired
vapor seal with the transparent layer and gasket. Other forms of
manufacture of the frame, such as by molding of engineered plastic
material is also within the scope of the invention.
[0024] The combination of the frame 12, transparent layer 18 and
gasket 20 provides a modular sight glass assembly suitable for use
in a wide variety of applications, and particularly suited for
vapor-controlled installations such as the described water heater
flame trap assemblies. The modular sight glass assembly is
particularly advantageous to the manufacturer of the end product as
it can be provided as a pre-assembled unit ready for final
installation, as further described. This produces substantial cost
savings over conventional manufacturing and assembly operations
wherein each component of a sight glass is handled separately.
[0025] As further shown in FIGS. 2-4, to install the sight glass
assembly in the described water heater flame trap, the frame 12 is
aligned with the opening 23 and pressed against cover panel 8 to
engage the tangs 22 of tabs 17 with the perimeter of opening 23.
The tangs 22 are sprung to extend past the edges of opening 23 once
inserted beyond cover panel 8, in permanent compressive engagement
of the frame 12 against the transparent layer 18, gasket 20 and
cover panel 8, to provide a vapor-proof sight glass in the water
heater flame trap. This embodiment substantially reduces the amount
of time required for installation of a sight glass assembly in the
flame trap type water heater.
[0026] An alternate embodiment of a modular vapor-proof sight glass
assembly 30 is shown in FIG.5, FIG.5A, and FIG.6. This embodiment
30 differs mainly from the first embodiment 10 with respect to the
manner of attachment of the frame 12 to the cover panel 8 of the
flame trap compartment 6. In this case, the side walls 16 have a
securing flange 37 which extends in the plane generally parallel to
the front face 13 of frame 32. Each flange 37 has a circular
opening 35 for fastener 36 such as a rivet, screw or other suitable
device to extend through the flange 37 and the wall section of the
cover panel 8.
[0027] The gasket 33 extends to meet the dimensions of the modified
frame 32, i.e. to traverse substantially the entire width of the
frame 37, and contains two openings 34 which correspond in location
with the fastener openings 35 in the frame 32.
[0028] FIG. 5A illustrates an alternate embodiment of the sight
glass assembly frame 32, wherein the top wall 14 and the bottom
wall 15 are formed by a single tab or flap-like element 38 bent
away from the face 13 of the frame 32. The single tab 38 is
centered on the wall, generally equidistant from the side walls 16,
which creates a stiffer overall structure and consequent increased
effectiveness in establishing the vapor barrier by compression of
the gasket against the cover panel.
[0029] The invention thus provides a cost-efficient modular sight
glass assembly configured for a wide variety of installations, and
particularly suited for use in a vapor-controlled environment such
as the described flame trap, or other types of gas or combustion
vessels or devices. The sight glass assembly is preferably
pre-assembled for final installation as a modular unit.
* * * * *