U.S. patent application number 13/308733 was filed with the patent office on 2012-12-06 for sliding dishwasher lid seal.
Invention is credited to Matthew Cosgrove.
Application Number | 20120306334 13/308733 |
Document ID | / |
Family ID | 36293202 |
Filed Date | 2012-12-06 |
United States Patent
Application |
20120306334 |
Kind Code |
A1 |
Cosgrove; Matthew |
December 6, 2012 |
SLIDING DISHWASHER LID SEAL
Abstract
In a dishwasher of the type where an open top wash chamber
slides out of a cabinet for loading and a closure is provided in
the cabinet to close the chamber during washing, the closure is
provided with a water sealing elastomeric gasket containing a
magnetic material and the wash chamber top edges with a
complementary magnetic material such that when the chamber is in
the washing position magnetic forces cause the flexible gasket to
extend into sealing contact with the wash chamber top edges.
Inventors: |
Cosgrove; Matthew;
(Auckland, NZ) |
Family ID: |
36293202 |
Appl. No.: |
13/308733 |
Filed: |
December 1, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11718305 |
Oct 18, 2007 |
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PCT/NZ05/00306 |
Nov 18, 2005 |
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13308733 |
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Current U.S.
Class: |
312/237 |
Current CPC
Class: |
A47L 15/0084 20130101;
A47L 15/4263 20130101; A61B 5/0059 20130101; G01N 21/31
20130101 |
Class at
Publication: |
312/237 |
International
Class: |
A47L 15/42 20060101
A47L015/42 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 2004 |
NZ |
536816 |
Claims
1. A dishwasher having a cabinet containing one or more wash
chambers wherein at least one wash chamber has an open top and
slides out of said cabinet from a washing position for loading and
unloading, and a closure mounted in said cabinet which closes the
top of said wash chamber during the washing process, characterised
in that a flexible gasket containing a magnetic material is
provided at the periphery of said closure, the edges of said wash
chamber defining said open top contain a magnetic material such
that when said wash chamber is in or nearly in said washing
position the magnetic force between said gasket and said chamber
cause said gasket to engage in a substantially water tight seal
with the top of said wash chamber, and wherein said closure is
mounted to permit a limited movement in the chamber sliding
direction, and on the chamber being moved a limited distance from
said washing position said closure remains sealed against said
chamber and moves with it and upon further movement a lifting force
on said gasket tends to break said seal to minimise the resistance
to wash chamber sliding motion due to a frictional force between
said gasket and said wash chamber edges when said gasket is engaged
with said chamber edges.
2. A dishwasher according to claim 1 wherein said magnetic material
provided in said gasket is a series of magnets.
3. A dishwasher according to claim 1 wherein said magnetic material
provided in said gasket is a series of magnets and are aligned with
said second set of magnets mounted in said cabinet so that opposite
poles are adjacent when said lid is sealed against said
chamber.
4. A dishwasher according to any one of claims 1, 2 and 3 wherein
said magnets are electromagnets.
5. A dishwasher as claimed in claim 1 wherein said magnetic
material in said gasket is provided as a series of distributed
parts, and a set of magnets are mounted in said cabinet above but
forward of said distributed parts of magnetic material, and during
opening said set of magnets align with corresponding parts of
magnetic material in said gasket and exert said lifting force.
Description
[0001] This application is a continuation application of U.S. Ser.
No. 11/718,305 which has been assigned a 35 U.S.C. .sctn.371 date
of Oct. 18, 2007. U.S. Ser. No. 11/718,305 is a 35 U.S.C. .sctn.371
of PCT/NZ05/00306 filed on Nov. 18, 2005. This application also
claims priority to NZ 536816 filed on Nov. 24, 2004.
FIELD OF INVENTION
[0002] This invention relates to dishwashers of the type employing
a wash chamber which slides in and out of a cabinet, or from
kitchen joinery, and in particular to means for sealably closing
the open top of the wash chamber.
PRIOR ART
[0003] Mechanisms for sealably closing the open top of sliding wash
chambers for dishwashers are disclosed in U.S. Pat. Nos. 5,470,142;
6,189,551; and 6,571,808.
[0004] The use of electric motors to lower a lid onto the top of a
wash chamber or electric pumps to inflate gaskets to form a seal
between a lid and the wash chamber add to the complexity of such
dishwashers and increase costs. Lids mechanically actuated by the
force required to extend or retract the sliding wash chamber avoid
these complexities but do not result in reliable lid seals due to
the fact that the gasket must inevitably engage the rim of the wash
chamber while the wash chamber is still undergoing horizontal
motion either on retraction or withdrawal.
SUMMARY OF INVENTION
[0005] It is an object of the present invention to provide a
dishwasher of the type described which overcomes the abovementioned
problems.
[0006] Accordingly in one aspect the invention consists in:
[0007] a dishwasher having a cabinet containing one or more wash
chambers wherein at least one wash chamber has an open top and
slides out of said cabinet from a washing position for loading and
unloading, and a closure mounted in said cabinet which closes the
top of said wash chamber during the washing process,
[0008] characterised in that a flexible gasket containing a
magnetic material fitted is provided at the periphery of said
closure, and the edges of said wash chamber defining said open top
contain a magnetic material such that when said wash chamber is in
or nearly in said washing position the magnetic force between said
gasket and said chamber cause said gasket to engage in a
substantially water tight seal with the top of said wash
chamber.
[0009] In a second aspect the invention consists in a magnetic seal
for the lid and wash chamber of a dishwasher of the type wherein
one wash chamber has an open top and slides out of said cabinet
from a washing position for loading and unloading and a closure
mounted in said cabinet which closes the top of said wash chamber
during the washing process, the improvement comprising:
[0010] a flexible gasket formed from a low friction material and
containing a magnetic material fitted to said closure which when
said wash chamber is in or nearly in the washing position is
attracted by magnetic force to engage in a substantially water
tight seal with the top of said wash chamber.
[0011] To those skilled in the art to which the invention relates,
many changes in construction and widely differing embodiments and
applications of the invention will suggest themselves without
departing from the scope of the invention as defined in the
appended claims. The disclosures and the descriptions herein are
purely illustrative and are not intended to be in any sense
limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows a dishwasher of the type to which the present
invention applies;
[0013] FIG. 2 shows a diagrammatic vertical longitudinal section of
a dishwasher with fixed rigid lid and single wash chamber;
[0014] FIG. 3 shows diagrammatically a sealing arrangement for the
FIG. 2 embodiment employing a magnetic gasket (at the side of the
wash chamber);
[0015] FIG. 4 shows one implementation of the sealing arrangement
of FIG. 1 at the side of the wash chamber of FIG. 3;
[0016] FIG. 5 shows a diagrammatic vertical longitudinal section of
a floating rigid lid alternative to FIG. 2 employing a magnetic
gasket with the wash chamber withdrawn;
[0017] FIG. 6 shows the FIG. 5 embodiment with the wash chamber
retracted;
[0018] FIG. 7 shows an interior view of a portion of the lid and
wash chamber for the FIG. 5 embodiment;
[0019] FIG. 8 shows a sealing arrangement for the FIG. 5 embodiment
of the front of the wash chamber;
[0020] FIG. 9 shows a sealing arrangement for the FIG. 5 embodiment
of the back of the wash chamber;
[0021] FIG. 10 shows a diagrammatic vertical longitudinal section
of a fixed rigid lid with a moveable magnetic gasket with the wash
chamber withdrawn;
[0022] FIG. 11 shows the FIG. 9 embodiment with the wash chamber
retracted;
[0023] FIG. 12 shows an alternative form of magnetic gasket for a
fixed rigid lid dishwasher; and
[0024] FIG. 13 shows diagrammatically a further embodiment where a
further set of magnets are incorporated in the dishwasher cabinet
above the lid to provide a force to break the gasket seal during
withdrawal of the tub from the cabinet.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The type of dishwasher to which the present invention is
applicable is shown in FIG. 1. One or two slideable wash chambers 1
are mounted in a cabinet 6, each wash chamber having its own
complete and independent wash system. The wash chambers are slid
out of the cabinet for top loading and washing operations in a
chambers is initiated when that chamber is retracted into a washing
position within the cabinet and its open top sealed by a lid or
other closure device which is mounted within the dishwasher cabinet
and remains in the cabinet upon withdrawal of the wash chamber. The
present invention is concerned with the manner in which such "lids"
or "closures" form a watertight seal with the wash chamber rim.
[0026] A first embodiment of the invention will be described with
reference to FIGS. 2 to 4. In this embodiment the dishwasher lid
and chamber rim have a wedge shaped configuration as shown in FIG.
1. When chamber 1 is fully retracted into the dishwasher cabinet in
the position illustrated (the "washing position") the chamber rim 2
almost touches the sealing edges 3 of lid 4. The vertical spacing
between rim 2 and edge 3 is then sufficiently small to allow the
sealing device 5 to form a water tight seal in a manner which will
now be described with reference to FIG. 3.
[0027] Lid 4 is mounted within cabinet 6 in a fixed horizontal and
vertical position. The periphery of lid 4 carries a gasket
indicated generally as 5. This comprises a compliant elastomeric
web section 7 which retains an abutment section 8 which in one form
is moulded about an iron insert 9. Abutment member 8 is intended to
abut against wash chamber rim 2 when the chamber is fully retracted
in cabinet 6. Wash chamber rim 2 contains a magnet member 10 which
extends continuously around the periphery of the rim and which is
embedded in the rim by moulding or some alternate insertion method.
When the wash chamber is almost fully retracted the magnet 10
attracts iron insert 9 downwards which causes the gasket 5 to
engage with rim 2 with the final portion of travel of the wash
chamber being conducted with the gasket sliding over the rim.
[0028] The material used for abutment member 8 must have the
appropriate properties to allow a sliding contact with chamber rim
2 with minimal wear over the lifetime of the dishwasher. Any wear
will ultimately result in leakage of water from the wash chamber
during washing operations. One preferred material is PTFE which may
either be in tape form adhered to the lower surface of the abutment
member or alternatively co-moulded onto the lower surface of the
abutment member. The material used for the sealing device web and
abutment member can be any suitable compliant elastomeric material
which is mouldable or extrudable.
[0029] Instead of using an iron insert in abutment member 8 a
magnet could be inserted here with an iron insert placed in the
wash chamber rim. As a further alternative it would be possible to
use electro-magnets on both sides which has the advantage that when
the wash chamber is to be withdrawn from the cabinet a repellent
force could be produced to release sealing device 5 from the wash
chamber rim.
[0030] Where electro-magnets with repel mode are not used, then on
withdrawal of the wash chamber from the cabinet the chamber rim 2
slides against the sealing device 5 with the complementary wedge
shape of lid 4 and wash chamber rim increasing the vertical spacing
therebetween as the drawer moves horizontally. At a certain point
the vertical spacing is such that the restoring force of the
sealing device 5 exceeds the magnetic attraction force and the
sealing device snaps away from the chamber rim.
[0031] The need for a low friction slip coat is not only to reduce
wear with usage, but also to reduce the force required to open the
dishwasher. That is, the horizontal force a user must apply to
withdraw the wash chamber from the cabinet. In production the
gasket 5 may be fixed to the lid 4 by mechanical means. A
configuration which allows this is shown in FIG. 4. The gasket 5 is
provided with an engagement member 11 extending from web 7 and this
is jammed within a channel or groove 12 formed around the periphery
of lid 4. Engagement member 11 may be provided with any profile
commonly used in the gasket art to ensure adequate retention within
the lid channel.
[0032] A second form of lid mechanism using a magnetic sealing
device will be described with reference to FIGS. 5 to 8. In this
embodiment the lid is floating rather than being fixed in a
vertical location and is arranged to move down onto the rim of the
wash chamber when the chamber is fully retracted into the
cabinet.
[0033] The form of floating lid 21 is best seen in FIG. 7 where
wash chamber 1 is shown fully extended from the cabinet. Lid 21
comprises a horizontal planar lid section proper 22 with integral
side flanges 23 and 24. Lid section 22 accommodates a magnetic
sealing device 25 about its periphery and this sealing device is
similar in principle to that already described with reference to
FIG. 3.
[0034] In this embodiment when the chamber is fully extended as
shown in FIG. 5 and FIG. 7, the front edge of the lid is held above
rim 2 of the wash chamber by a pair of rollers 26 mounted at the
front ends of lid flanges 23 and 24. These rollers roll along the
outer edges of chamber rim 2 when the chamber is retracted and
extended from the cabinet.
[0035] The interior surfaces of lid flanges 23 and 24 are provided
with two camming surfaces 27 and 28. The wash chamber is provided
with a pair of rollers 29 on each side of the rear face of the
chamber through lugs 30. Chamber rollers 29 engage with respective
cam surfaces 27 and 28 to cause the rear of the lid to be raised as
the chamber is retracted.
[0036] The side extremities of the chamber rim 2 which align with
the tracks of rollers 26 are provided with semi-circular
depressions 31 which together with the edges of rim 2 form a cam
surface for rollers 26. When the chamber is almost fully retracted
rollers 26 commence to enter semi-circular sections 31 to allow the
front of the lid structure to move down towards the wash chamber
rim. At the same time the chamber rollers 29 (see FIG. 6) enter the
upward portion 32 of cam surface 27 to allow the rear of the lid to
descend down onto chamber rim 2. The lid rests on the rim of the
wash chamber by virtue of its own weight but sealing of the wash
chamber is effected by gasket 5 snapping to the magnet provided in
the chamber rim to be held closed in a watertight seal by the
applied magnetic forces.
[0037] With this lid embodiment the magnetic sealing device does
not require a compliant elastomeric web section since it is not
necessary for the abutment portion of the seal to move horizontally
in relation to the lid while still bearing against it. In this
embodiment the lid moves in the vertical direction and the sealing
device may be rigidly connected to the lid. A suitable
implementation of magnetic seal is shown in FIG. 8. A magnet 10 is
provided in rim 2 as in the previous embodiment, while an iron
insert 33 is attached to the lid by a resilient extruded member 34.
Iron insert 33 is still provided on its lower surface with a low
friction slip coat 35, but this is simply to reduce the opening
force required to pull the sliding wash chamber out from the
cabinet.
[0038] A third form of lid configuration will now be described with
reference to FIGS. 10 and 11. In this embodiment the lid is fixed
within the dishwasher cabinet with the lid sealing device having
extended movement in the vertical direction controlled by rollers
mounted either side at the front of the sealing device which run on
cam surfaces provided in the rim of the wash chamber as in the
second described embodiment.
[0039] Lid 41 is fix mounted in the top of the cabinet and can be
inclined front to rear as shown or can be horizontal. The lid
carries at its periphery a magnetic sealing device 42 similar to
those described in connection with the previous embodiments of the
invention. However in this case in one form (that shown in FIG. 10)
magnetic material only needs to be incorporated in the sealing
device along the front and rear edges of the lid because the
sealing device is provided with front to rear stiffening members 43
on each side of the lid.
[0040] The sealing device thus floats from the lid in a similar
manner to that described with reference to the first embodiment of
the invention. However in the present embodiment a wedging action
between chamber rim and lid is not used and thus the sealing device
must be maintained above and clear of the chamber rim until the
chamber is substantially in the washing position. To achieve this
requirement two side mounted rollers 34 are attached to the lower
surface of the sealing device 42. Rollers 44 run in tracks or cam
surfaces provided in the outer edges of the chamber rim. One end of
those cam surfaces assumes the form of a semi circle 31 into which
roller 44 may drop on full retraction of the chamber. The opposite
edge of the cam surfaces has a ramped lead-in portion 45 to guide
the roller up onto the central portion of the cam surface upon
initial insertion of the chamber into the cabinet.
[0041] In operation, as the chamber is retracted back into the
cabinet, rollers 34 hold the front of the sealing device above the
chamber rim and by virtue of the presence of stiffeners 43 keep the
sealing device clear of the rim until the chamber is nearly fully
retracted when the vertical spacing between the rear chamber rim
and the rear sealing device magnet reduces sufficiently for the
magnetic forces to snap the seal onto the rim. When the chamber is
fully retracted the rollers 44 descend into the semi circular cam
surfaces 31 allowing the front and sides of the sealing device to
snap onto the chamber rim under the influence of the magnetic
forces.
[0042] The surfaces of the sealing device are provided with a slip
coat so that the rear edge of the sealing device may easily slide
over the rim with the aid of ramped section 45. In addition to this
electro-magnets may be used so that until the chamber is fully
retracted cause a repulsive force to exist between the chamber rim
and the sealing device to ensure the sealing device remains clear
of the chamber.
[0043] In practical implementations of the magnetic sealing device
disclosed it may be necessary to incorporate a lip seal to ensure a
fully watertight seal when dirt particles contaminate the abutting
surfaces. A magnetic sealing gasket incorporating a lip seal is
shown in FIG. 12. In the form shown a compliant elastomeric web
section 51 is anchored about the periphery of a fixed lid 4 with
its distal extremity being forked in cross section to provide three
web sections 52, 53 and 54. Web sections 52 and 53 each carry
respective magnetic material inserts 55 and 56. Alternatively web
sections 52 and 53 may be attached to the magnetic material other
than by overmoulding in which case the magnetic material is covered
with a low friction slip coat.
[0044] Central web section 54 is configured to provide an abutment
portion 57 at its distal edge with a central section 58 provided
with resilience to urge the abutment portion 57 onto the rim of the
chamber when in the closed or sealing position.
[0045] In a further embodiment where the lid is fixed vertically
and magnets are contained in the gasket the lid is allowed to move
horizontally for a short distance with the tub on opening so that
the gasket magnets align with another set of magnets mounted in the
dishwasher cabinet above the lid which provide an attraction force
to break the gasket seal to the tub.
[0046] FIG. 13 shows a tub which has been withdrawn a distance "d"
from the dishwasher cabinet. (Distance d has been exaggerated in
FIG. 13). In this embodiment a second set of magnets 61a to 61d
(only four are shown for illustrative purposes) is mounted in the
cabinet chassis 6 immediately above lid 4. This set is forwardly
displaced by distance d relative to the positions of the gasket
magnets 62a to 62d when the tub is fully retracted within the
cabinet. The chassis magnets 61 are oriented so that the polarity
of the (N) poles which face the lid(s) is opposite to the polarity
of the poles of the gasket magnets 62 which face the lid.
[0047] When the tub is withdrawn by d the two sets of magnets 61
and 62 align and the resultant attraction force tends to lift the
gasket 5 off the tub rim 2 in opposition to the attracting force
between the gasket magnets 62 and the magnetic material in the tub
rim 2.
[0048] The inevitable spacing between the chassis magnets 61 and
the gasket magnets 62 means the lifting force will not exceed the
sealing force unless expensive powerful rare earth magnets or
electromagnets are used for magnets 61. In this embodiment of the
invention it is proposed that only a few of the chassis magnets be
of this type. Once these magnets lift a section of the gasket from
the tub rim the section of the gasket under the next ordinary
magnet 61 will be moved closer to it and with the reduced spacing
the stronger attraction force will overcome the sealing force
exerted on that section. Once that section has in turn lifted the
same effect will occur on the next adjacent gasket section. The
process will ripple around the gasket to "peel" it completely off
the tub rim. The tub can then be further withdrawn without
resistance due to the magnetic gasket sealing forces.
* * * * *