Note: Descriptions are shown in the official language in which they were submitted.
CA 02546235 2006-05-11
Docket No.:5909-25
THREADED MACK WASHER
Background Of The Invention
[0001] Lavatories and bathtubs include a pluggable drain connected to a waste
pipe.
When a person wishes to wash, the drain is plugged and water is allowed to
collect in
the lavatory or tub. When finished washing, the person unplugs the drain to
permit
the waste water to drain away to a sewer.
[0002] The plugging function is usually accomplished by a pop-up. The pop-up
typically includes a threaded body inserted into the drain hole of the
lavatory. A
flange extends radially outwardly from the body to cover any gaps between the
pop-
up and the sidewall defining the drain hole and to provide a finished
appearance to the
drain. A nut and friction washer engage the threaded body and the bottom of
the
drain hole, as illustrated in Figure 2 cooperating with the flange to retain
the pop-up in
place. A mack washer is typically installed between the friction washer and
the drain
hole to seal the space between the drain hole and the pop-up body. However, as
illustrated in Figure 3, a gap exists between the inner wall of the mack
washer and the
minor diameter of the threaded portion of the pop-up body, thereby providing a
path
for seepage to occur. In addition, tightening a lock nut to urge the mack
washer into
sealing engagement with the lavatory tends to pull the bottom of the mack
washer
away from the pop-up body, thereby increasing the likelihood of seepage.
Summary Of The Invention
[0003] The present invention overcomes these and other problems by providing
an
effective seal against the threaded portion of the pop-up body. The present
invention
includes a mask washer having an internal surface with helical seal that
engages the
threads on the pop-up body and a beveled extension depending from the bottom
of the
mack washer. The helical seal follows the shape of the threads on the pop-up
body
and assumes the shape of the threads, extending generally to the minor
diameter of the
threads, thereby eliminating the seepage problem. In certain embodiments, the
helical
seal can be interrupted to facilitate engagement. The lock nut preferably
includes a
beveled seat configured to engage the beveled extension and urge the beveled
extension into further contact with the pop-up body, thereby increasing the
sealing
effect of the mack washer and preventing the bottom of the mack washer from
pulling
away from the pop-up body as the lock nut is tightened.
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[0004] ~ Other features and advantages will become apparent from the following
description when viewed in accordance with the accompanying drawings and
appended
claims.
Brief Description Of The Drawings
[0005] Figure 1 is a partially broken-away view of a lavatory illustrating a
pop-up
installation.
[0006] Figure 2 is a section view of the pop-up of Figure 1 with a
conventional mack
washer.
[0007) Figure 3 is a partial section view of the lavatory of Figure 1
illustrating a pop-
up with a conventional mack washer.
[0008] Figure 4 is a perspective view of a mack washer according to the
present
invention.
[0009] Figure S is a section view taken through the mack washer of Figure 4
and a
lock nut for use with the mack washer.
[0010] Figure 6 is a partial section view of the lavatory of Figure 1
illustrating the
mack washer according to the present invention as installed on a pop-up.
[0011] Figure 7 is a section view of an alternative embodiment of the mack
washer.
[0012] Figure 8 is a section view of the lavatory of Figure 1 illustrating the
alternative
mack washer as installed on a pop-up.
Detailed Description Of The Drawings
[0013] Figures 1 and 2 illustrate a conventional installation of a pop-up 10
in a
lavatory 12. A spout 14 includes a pop-up rod 16 connected to an adjustable
connector 20 which, in turn, is attached to an actuator 22. The actuator 22
extends
into the body 24 of the pop-up 10 and connects to a stopper 26 that is movable
up and
down along the axis A of the pop-up 10. Movement of the pop-up rod 16 causes
the
actuator 22 to pivot about a ball joint 30 to move the stopper 26 up and down
to open
and close the drain.
[0014] Figure 3 illustrates the installation of a conventional mack washer 32
on the
pop-up 10. Typically, the pop-up body 24 includes external threads 34 to
accept a
lock nut 36. The mack washer 32 includes a beveled portion 38 configured to
abut
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the bottom surface 40 of the lavatory drain 42 and a flat inner surface 39
configured to
seal against the threads 34. A friction washer 44 is disposed against the
bottom of the
mack washer 34 and the lock nut 36 abuts the bottom of the friction washer 44.
Unfortunately, as illustrated in Figure 3, the conventional mack washer 32
does not
reach in to the minor diameter D of the threads 34, thereby leaving gaps 46
between
the muck washer 32 and the threads 34 of the pop-up body 24. Those gaps 46
allow
seepage past the mack washer 32, causing consumer complaints. In addition,
increased tightening of the lock nut 36 tends to cause the mack washer to
pivot about
the inner edge of the bottom surface 42 of the lavatory, pulling the bottom of
the
mack washer 32 away from the threads 34, further aggravating the seepage
problem.
[0015) Figures 4-6 illustrate a mack washer 50 according to the present
invention.
The mack washer 50 includes an inner surface 52, an upper surface 54, a lower
surface 56, and a beveled annular sealing portion 60 extending downwardly from
the
lower surface 56 at the inner surface 52. The upper surface 54 includes a
beveled
portion 62 that extends radially outwardly and downwardly. The inner surface
52
includes helical seals 64 that conform to the external threads 34 on the pop-
up body
24 and generally extend into the minor diameter D, thereby eliminating the
seepage
problem associated with conventional mack washers 32. In certain embodiments
of
the invention, the helical seals 64 are interrupted, as indicated at 66.
[0016) A lock nut 70 includes a beveled sealing surface 72 configured to match
and
engage the beveled annular sealing portion 60 of the mack washer 50. Internal
threads 74 engage the external threads 34 of the pop-up body 24. Tightening
movement of the nut 70 on the external threads 34 urges the beveled sealing
surface
72 into sealing engagement with the annular sealing portion 60, urging the
sealing
portion 60 into tighter contact with the external threads 34, thereby
preventing the
mack washer 50 from pivoting about the inner edge of the bottom surface 40 and
providing additional protection against seepage.
[0017) Figure 7 illustrates an alternative embodiment of the invention. Mack
washer
80 includes a beveled sealing portion 81 and at least two sets of interrupted
helical
seals 82, 84. The first set of helical seals 82 are configured as fine threads
for use
with a metal pop-up body, whereas the second set of seals 84 are configured as
coarse
threads for use with a plastic pop-up body. In certain embodiments, each set
of seals
82, 84 comprise two segments disposed 180° apart and extending about a
quarter of
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the way around the circumference of the inner surface 86. In addition, the
seals 82,
84 alternate around the circumference, leaving a gap 88 between each set of
seals.
[0018] Figure 8 illustrates the mack washer 50, 80 installed on the pop-up
body 24
and secured by a friction washer 90 and a conventional lock nut 92. The
friction
washer 90 includes a beveled sealing surface 94 configured to mate with the
beveled
sealing portion 60 of the mack washer 50, 80. The lock nut 92 urges the
friction
washer 90 into engagement with the mack washer 50, 80.
[0019] The present invention further includes a method of sealing a pop-up
body in a
drain opening. A pop-up having an externally threaded body is positioned in
the drain
opening and a mack washer is installed on the threaded body below the drain
opening.
Preferably, the mack washer includes an inner surface with at least one
helical seal
configured to engage the threads of the pop-up body. A lock nut having
internal
threads configured to engage the threaded body is positioned against the
bottom
surface of the mack washer, urging the mack washer into sealing engagement
with the
bottom of the drain opening and the threads of the pop-up body.
[0020] In one preferred embodiment, the mack washer further includes an
annular
sealing portion extending downwardly from the bottom surface and the lock nut
further includes an upper surface having a beveled portion configured to match
and
engage the annular sealing portion.
[0021] In another preferred embodiment, the mask washer includes an annular
sealing
portion extending downwardly from the bottom surface and a friction washer
includes
an annular sealing portion configured to mate with and engage the annular
sealing
portion. The friction washer is disposed between the mack washer and the lock
nut,
so that the lock nut urges engagement between the friction washer and the mask
washer.
[0022] The above-described embodiments, of course, are not to be construed as
limiting the breadth of the present invention. Modifications and other
alternative
constructions will be apparent which are within the spirit and scope of the
invention
as defined in the appended claims.
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