Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02325514 2004-05-12
TUB OVERFLOW WASTE ASSEMBLY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to overflow waste assemblies for tubs such as
bathtubs and spas, and more particularly, to an overflow waste assembly
utilizing
a screw-in retaining body in combination with an elbow fitting having at least
one
fulcrum member permitting engagement with a tub wall at various angles and an
annular gasket providing a reliable, water-tight seal on the tub interior
without an
exterior tub gasket. This invention also relates to an overflow waste assembly
having a polymeric screw-in retaining body with a removable, integrally molded
test plug and attached handle member.
2. Description of Related Art
The use of waste water overflow drains in tubs such as bathtubs and spas
is well known. Such overflow drains are typically located at or near the
maximum
intended fill level of the tub and in proximity to plumbing connecting the
main tub
drain to a sewer line. Prior art fittings for tub waste overflows are
disclosed, for
example, in the following United States patents: 1,010,469; 1,781,719;
2,052,565; 2,223,365; 2,243,204; and 5,890,241. Test plugs for hydraulic
testing
of plumbing systems are disclosed, for example, in U.S. patents 4,763,510;
5,507,501 and 5,890,241.
Tub waste overflows usually comprise some type of fitting that connects a
portion of the fitting on the inside of the tub to a drain line disposed
behind the
tub wall. A cover plate having recesses that admit water but not foreign
objects
into the drain system is generally provided on the inside of the tub. Sealing
gaskets are desirably utilized on both sides of the tub wall to prevent water
from
leaking around the fitting. Because tub wall angles can vary significantly,
tub
waste overflow assemblies are desirably adaptable to provide a water-tight
connection when installed in tubs having different wall angles, preferably
while
maintaining a substantially vertical waste drop. Tub waste overflow assemblies
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should also be capable of being hydraulically tested following installation
without
having to break the tub seal.
In applicant's U.S. Patent No. 6,192,531, issued February 27, 2001, a tub
waste overflow assembly is disclosed that is attachable to a tub wall by means
of
a threaded retaining body insertable through an overflow drain aperture in a
tub
wall to engage a cooperatively threaded pipe fitting on the opposite side of
the
tub wall. A chamfered washer is provided to cooperate with the retaining body
and an annular sealing gasket to produce a fluid-tight seal on the interior
surface
of the tub wall and frictionally engage a cover member spanning the overflow
drain aperture. Optionally, a removable test plug is molded in place across
the
mouth of the retaining body to facilitate hydraulic testing following
installation.
While this apparatus represents a significant and valuable improvement over
prior art devices, there remains a need for a tub overflow waste assembly that
does not require the use of an exterior tub gasket to accommodate various tub
and elbow angles, and that does not require the use of tools to install the
waste
assembly on the tub. Such an apparatus is disclosed herein.
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SUMMARY OF THE INVENTION
A tub waste overflow assembly is disclosed herein that is attachable to
a tub wall by means of a threaded retaining body insertable through an
overflow drain aperture in a tub wall to engage a cooperatively threaded pipe
fitting on the opposite side of the tub wall. According to one preferred
embodiment of the invention, a retaining body having an externally threaded
end is insertable through a tub overflow waste hole, and is cooperatively
alignable with the female end of an oppositely disposed drain pipe fitting
outside the tub. A forwardly facing annular flange on the cylindrical
retaining
body compresses a sealing gasket and washer against the interior tub wall,
thereby eliminating the need for a' rear tub seal. A fulcrum member is
desirably provided on the back side of the tub wall between the tub wall and
a facing annular flange on the drain pipe fitting to facilitate connection
with
the retaining body over a range of angular relationships between the tub wall
and the assembled elbow and retaining body. The retaining body preferably
has an annular recess disposed between the threads and flange for seating a
sealing ring preventing leakage between the drain pipe fitting and the
retaining body behind the tub wall.
The internal bore of the retaining body preferably has an integral test
plug with an attached handle member having wings projecting toward the tub
interior. The wings are useful for manually threading the retaining body into
the elbow and for tightening the retaining body and gasket against the tub
wall without the need for tools. The test plug and handle member can be
removed by knocking them out of the retaining body bore following
installation and pressure testing.
According to another embodiment of the invention, a tub waste
overflow assembly is provided having a pipe fitting with female threads on
the end adjacent the tub and a forwardly facing annular flange with at least
one fulcrum member. The fulcrum member contacts the exterior tub wall
adjacent to the waste hole and facilitates attachment of the assembly to tub
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walls over a range of angles between the flange and tub wall without the need
for
a gasket on the exterior of the tub wall. Most preferably, the forwardly
facing
annular flange comprises two diametrically opposed fulcrum members projecting
outwardly toward the tub. The fitting is most preferably an 83° molded
plastic
elbow attached to a drain pipe and having female threads on the end nearest
the
tub, although other fittings and elbows with other included angles can also be
used within the scope of the invention. An externally threaded retaining body
attachable to the pipe fitting, a chamfered washer, and an annular sealing
gasket
are preferably provided to produce a fluid-tight seal on the interior surface
of the
tub wall when the retaining body is inserted partially through the tub waste
hole
from the inside of the tub, and threaded into engagement with the pipe fitting
behind the tub wall. An o-ring seal is preferably provided between the outside
surface of the retaining body, forwardly of the threaded section, and the
interior
of the elbow to prevent any fluid leaking past the threads from wetting the
space
behind the tub wall.
According to another preferred embodiment of the invention, a removable
test plug is molded in place across the mouth of the retaining body to
facilitate
hydraulic testing following installation, and a molded plastic handle member
is
attached to the test plug, preferably unitarily molded with the test plug, to
facilitate installation of the tub overflow waste assembly without tools.
Following
hydraulic testing, the test plug and handle member are removable by the
application of sufficient force to the handle member to rupture an annular web
connecting the test plug to the remainder of the retaining body. Following
removal of the test plug and handle member, a cover can be placed over the
assembly and attached by any suitable means such as fasteners, biasing
members, frictional engagement, and the like.
According to an aspect of the present invention, there is provided a tub
overflow waste assembly attachable to a tub wall through an aperture in the
tub
wall, the assembly comprising; a retaining body insertable through the
aperture,
the retaining body having an axial bore with external threads and a first
annular
flange disposed inwardly of the tub wall; a drain pipe fitting disposed
outwardly of
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the tub wall, the fitting having internal threads cooperatively aligned and
reversibly engageable with the external threads of the retaining body, and a
second annular flange facing the tub wall around the aperture; at least one
fulcrum member projecting forwardly of the second annular flange to contact
the
tub wall when the external threads of the retaining body are threaded into the
internal threads of the fitting; a sealing member disposed between the first
annular flange and the tub wall; a removable test plug traversing the axial
bore
adjacent the first annular flange; and a handle member attached to the test
plug
and projecting away from the aperture into the tub.
According to another aspect of the present invention, there is provided a
tub overflow waste assembly attachable to an internally threaded drain pipe
fitting through an aperture in a tub wall, the assembly comprising; a
retaining
body insertable through the aperture, the retaining body having an axial bore
and
a cylindrical wall with external threads and a first annular flange disposed
inwardly of the tub wall, the external threads being cooperatively aligned and
reversibly engageable with the drain pipe fitting; a sealing member disposed
between the first annular flange and the tub wall; a removable test plug
traversing the axial bore adjacent the first annular flange; and a handle
member
attached to the test plug and projecting away from the aperture and into the
tub.
This apparatus represents a significant and valuable improvement over
prior art devices that require the use of an exterior tub gasket to
accommodate
various tub and elbow angles, and that require the use of tools to install the
waste assembly on the tub.
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BRIEF DESCRIPTION OF THE DRAWINGS
The apparatus of the invention is further described and explained in
relation to the following figures of the drawings wherein:
FIG. 1 is a simplified, cross-sectional, front elevation view of a
preferred embodiment of the tub overflow waste assembly of the invention as
5 installed in the waste hole of a tub wall;
FIG. 2 is a front elevation view of the elbow portion of the tub overflow
waste assembly of the invention as shown in FIG. 1, showing one of the
projecting fulcrum members on the flange face;
FIG. 3 is a side elevation view of the elbow shown in FIG. 2, showing
two diametrically opposed pivot fulcrum projections on the flange face;
FIG. 4 is an exploded view of the installed tub overflow waste
assembly of FIG. 1;
FIG. 5 is a side elevation view of the retaining body of FIGS. 1 and 4;
and
FIG. 6 is a cross-sectional elevation view taken along line 6-6 of FIG.
5.
Like reference numerals are used to indicate like parts in all figures of
the drawings.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. I and 2, tub overflow waste assembly 10 of the
invention preferably comprises retaining body 14, chamfered washer 16 and tub
gasket 18. Retaining body 14 is preferably adapted for insertion through
aperture 28 in tub wall 20 and for threaded engagement with internally
threaded
female end 38 of a drain pipe coupling such as elbow 12 disposed behind tub
wall 20.
Referring to FIGS. 1-4, elbow 12 is preferably a molded plastic article
having two substantially transverse internal bore sections with center lines
intersecting at an angle 21 ranging from about 83° to about 90°.
Referring to
FIGS. 1, 4 and 6, retaining body 14 preferably comprises a substantially
cylindrical bore 46, an externally threaded section 34, an annular flange
having
inclined surface 40 and forwardly facing surface 56, and a plurality of
circumferentially spaced, forwardly projecting lugs 50. Annular recess 15 is
desirably provided between externally threaded section 34 and the annular
flange of retaining body 14 to seat a sealing ring 13, most preferably an
elastomeric o-ring, that seals against the interior of elbow 12 to prevent any
water that might leak past threaded section 34 into the space behind the tub.
Although retaining body 14 can be made of metal, it is preferably made of a
durable polymeric material such as acrylonitrile butadiene styrene terpolymer
("ABS"). According to a particularly preferred embodiment of the invention,
retaining body 14 is made of a moldable polymeric resin, and further comprises
a
relatively thin, disk-shaped, knock-out test plug 44 traversing axial bore 46.
Test
plug 44 is either unitarily molded in place or otherwise provided interiorly
of
forwardly facing surface 56 to facilitate hydraulic testing. Handle member 48
is
desirably attached to test plug 44 and projects forwardly toward the tub
interior.
Handle member 48 permits retaining body 14 to be installed in aperture 28 of
tub
20 without tools. The thickness of test plug 44 is preferably adequate to
resist the
torque required to thread retaining body 14 into elbow 12 and to resist
rupture
when exposed to the
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hydraulic pressures encountered during leak testing but susceptible to being
removed following such testing., Although not shown in the drawing, a
beveled recess can be provided around the edges of test plug 44 to weaken
the edges of the plug and facilitate its removal. Following installation and
hydraulic testing, test plug 44 and handle member 48 can be removed by the
application of force to handle member 48.
Referring to FIGS. 5 and 6, handle member 48 preferably comprises
stem portion 52 projecting forwardly from test plug 44 and wing members 54
projecting radially outward from the stem portion 52. Wing members 54 can
be easily grasped by the user when threading retaining body 14 into elbow
12 during installation (FIGS. 1 and 4). While the structure shown in the
drawings is preferred, it should be understood that the configuration of
handle member 48 can vary within the scope of the invention so long as the
handle is easily graspable by the user and is attached to test plug 44 in such
manner that more force is required to detach handle member 48 from test
plug 44 than is required to detach test plug 44 from the remainder of
retaining body 14. Thus, for example, stem 52 can comprise a forwardly
projecting cylindrical wall attached to test plug 44 and wings 54 can project
radially outward from the cylindrical wall. Where retaining body 14 is molded
- 20 from a polymeric resin, mold design considerations will necessarily
affect the
preferred configuration of handle member 48.
Test plug 44 and handle member 48 can be unitarily molded together
with the remainder of retaining body 14, or retaining body 14 can be molded
in parts that are then attached: by other similarly effective means such as
sonic welding, spin welding, sowent dasea aanesives, yr me m
Circumferentially spaced, forwardly projecting lugs 50 are desirably provided
on flange surface 56 for use in threading or unthreading retaining body 14
from elbow 12 following the removal of test plug 44 and handle member 48.
It should be understood that lugs 50 can likewise be located at other
positions on surface 56 within the scope of the invention.
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Referring again to FIGS. 1 and 4, during installation of tub overflow waste
assembly 10 on tub wall 20, the externally threaded end of retaining body 14
is
inserted through chamfered washer 16 and interior tub gasket 18, then through
aperture 28 in tub wall 20 and into threaded engagement with female threads 38
of elbow 12. Handle member 48 on retaining body 14 is useful for rotating
retaining body 14 relative to elbow 12 during tightening of assembly 10.
Threaded section 34 of retaining body 14 will desirably engage threads 38 of
elbow 12 sufficiently that o-ring 13 in annular recess 15 engages the smooth
interior flange portion of elbow 12.
As retaining body 14 is threaded into elbow 26, inclined annular flange
surface 40 of retaining body 14 desirably contacts and abuts against
correspondingly inclined, chamfered annular surface 42 of washer 16.
Chamfered washer 16 is preferably made of polypropylene or any other similarly
useful, durable polymeric material and further comprises a substantially
cylindrical collar section 58 adjacent to annular surface 42. The inside
diameter
of cylindrical collar section 58 is desirably slightly greater than the
outside
diameter of male threaded section 34 of retaining body 14 to permit threaded
section 34 to extend through it in a closely fitting relationship whenever
inclined
annular surface 40 of retaining body 14 is fully seated against chamfered
annular
surface 42 during tightening. Chamfered washer 16 preferably has a stepped
outside wall having an outside diameter greater than the diameter of aperture
28
through tub wall 20, and a recessed cylinder wall 32 having a diameter
slightly
less than the diameter of aperture 28. Recessed cylinder wall 32 locates
chamfered washer 16 in aperture 28. The annular flange shoulder extending
radially outward from wall 32 is preferably sufficiently wide to overlap the
interior
surface of tub wall 20 around aperture 28 and provide sufficient surface area
contacting interior tub gasket 18 to produce a fluid-tight seal relative to
aperture
28 whenever retaining body 14 is tightened relative to elbow 12. Interior tub
gasket 18 is preferably made of rubber, such as ethylene propylene diamine
rubber (EPDM), or any other compressible material that is similarly useful as
a
gasket between retaining
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9
body 14 and the interior surface of tub wall 20. If desired, following removal
of test plug 44 and handle member 48, cover 17, shown in phantom outline in
FIG. 1, made of metal or plastic can be attached by frictional engagement at
locations spaced around the perimeter of washer 16, or otherwise, over the
open end of retaining body 14. Such a cover will have slots or the like
permitting water to flow past the cover and into retaining body 14 and drain
pipe elbow 12.
In~ the past, relatively thick, elastomeric sealing rings have been
provided around the waste hole on the outside of tub walls to facilitate
attachment of a drain pipe fitting andlor to provide a fluid-tight seal. Such
"back-side" gaskets were often needed to adjust for variations in the included
angle between the annular face of the elbow or other drain pipe fitting and
the tub wall. Such angular variations can be caused by different slopes in
the tub wall, by the use of elbows having slightly different angles, or by
drain
pipes installed at slightly irregular angles. According to one embodiment of
the invention disclosed herein, as described in relation to FIGS. 1-4., elbow
12 preferably comprises at least one fulcrum member 26, most preferably
having a curvilinear surface, projecting outwardly from the forwardly facing
surface 24 of annular flange 22. According to a particularly preferred
embodiment of the invention, two diametrically opposed, elongated,
curvilinear fulcrum members 26 are disposed on face 24 of annular flange
22. When elbow is molded from a polymeric material, fulcrum members 26
can be unitarily molded onto the face of the flange. Fulcrum members 26 are
desirably positioned so as to make abutting contact with that portion of
outside surface 30 of tub 20 that is adjacent to aperture 28 so that elbow 12
can be pivoted on fulcrum members 26 relative to tub 20, varying angle 23 to
facilitate the alignment of internal threads 38 of elbow 12 with external
threads 34 of retaining body 14. It will also be appreciated by those of
ordinary skill in the art upon reading this disclosure that other similarly
effective means can be provided within the scope of the invention to function
as a fulcrum member between elbow 12 and tub 20.
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Other alterations and modifications of the invention will likewise
become apparent to those of ordinary skill in the art upon reading the present
disclosure, and it is intended that the scope of the invention disclosed
herein
be limited only by the broadest interpretation of the appended claims to
5 which the inventor is legally entitled.
