Note: Descriptions are shown in the official language in which they were submitted.
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tMP~QV~MeNTs 1N ~o~~~ss w~'rER IMM~RSI~~
HEATING fMPf~EMENTS
The present invention relates to improvements in cordless water
immersion heating implements such as kettles and jugs.
Cordless kettles and Jugs are becoming ever increasingly popular,
however, the design of such implements particularly when an auto turn-off
facility is required upon boiling of water is difficult and creates
manufacturing
problems with increased costs. It is conventional in this art for jug or
kettle
manufacturers to build the implement around an available control or control in
1 0 combination with an immersion heating element which is supplied to them by
a
specialist supplier of such controls. Thus, the control is either a single
unit
combined in a particular arrangement or it is a number of separate elements
which need to be separately installed in the kettle or jug. These conventional
arrangements have a number of perceived problems which include
'1 5 (i) that the thermally sensitive switch such as a bimetal or similar
device
provided to disconnect power on a boil condition is either located in the
top of the kettle or jug requiring wiring to be supplied from the base
region of the kettle or jug where the remainder of the controls are located,
or it is located with the other controls in the base region requiring a
20 relatively complicated external steam delivery path to the switch;
(ii) that power interconnect system between the power supply base and the
cordless kettle or jug is normally specific such that the kettle or jug can be
connected to the base in only one particular orientation;
(iii) that the controls together with at least part of the power
interconnection
25 between the base and the jug ar kettle are commonly largely carried by
the Jug or kettle thereby requiring the use o1 a bulky and unsightly
housing section to hold same usually located beneath the handle. This
control housing section, in many designs also takes up at least part of the
possible water holding volume within the kettle or Jug; and
30 (iv) , that the thermally responsive switch (such as a bimetal) and
commonly
many other parts of the control are produced as separate elements and
placed in an assembly (or partial assembly) in simple Juxtaposition with
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other control elements rather than truly integrating the various parts to
limit the complication, cost and size of the corrtrol assembly as a whol~.
We will hereinafter refer to "kettles" but it will be understood that this
term
will include jugs and any other similar water immersion heating implement.
' The objectives of the present invention are to provide improved
arrangements In kettles (particularly so-called cordless kettlos) whioh will
overcome or minimise at least some of the aforementioned problems associated
with conventionally known devices.
According to a first aspect of the present invention, there is provided an
electrically operated water immersion heating device comprising a base section
adapted to be conn~cted fio a power source, an upper section defining a water
retaining vessel having an immersion heating moans located therein, ,and
power connection means between said upper section and said base section
allowing said upper section to be detached, when desired, from said base
1 5 section, said power connection means enabling electric power to be
supplied to
said heating means when said upper section is operably connected to said
base section, said d~vice being characterised by the provision of a steam flow
path communicating with an upp~r region of Bald upper section of the device
and axtvnding to a position within said base soctlon, and a thermally
responsive
switch means arranged in said base section to discontinue the supply o~f power
to said heating means upon steam passing down said steam flow path when a
boil condition occurs in said water retaining vessel.
Conveniently, said power connection moans is such as to permit said
upper section to be oQerably connected to said base section in more than one
relative rotational position. Preferably, said upper section is operably
connectable to said baso section 1n any relative rotational position about an
axes
of rotation. Conveniently, said stoam slow path includes an annular or part
rannular trap soctian looated batwoon said upper and base sections of the
d~vice. The annular (or part annular) trap section may be located in the
bottom
~ Q of said upper section or the top of said bas~ section or partially in both
said
upper and base sections, Conveniently, opening means or passage means
loads from said annular (or part annular) trap section to a position at toast
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adjacent the thermally responsive switch means.
In a further aspect, the present invention provides an electrically operated
water immersion heating device, said device including power supply means
comprising at least a first electrical contact member moveable into electrical
engagement with a second electrical contact member to allow pewer to be
supplied therethrough to an electrical resistance immersion heating means, at
least one of said first and second contact members losing formed by a
thermally
responsive electrically conductive member which is capable of movement
between a first position establishing an electrically conductive path between
said first and second contact members and a second position breaking said
electrically conductive path between said first and second contact members
upon said thermally responsive electrically conductive member sensing a
predetermined temperature, and a steam flow path leading from an upper
region of said device to a position at least adjacent to said thermally
responsive
15' al~Gtrically conductive member so as to move said member to said second
position upon steam flowing along said flow path, Preferably, manually
operable reset means is provided to move said thermally responsive
electrically
conductive member to said first position as desired. The aforesaid arrangement
may be provided 1n a power supply arrangement for a conventional kettle or
mar be arranged in the power connection between a base section and an
upper section of a cordless kettle. The arrangement may of course be provided
in any of the previously described immersion h~ating devices according to 'the
present invention.
Several preferred ~mbodiments will now be described with reference to
they accompanying drawings although it will b~ apparent to those skilled In
the
art~~that other arrangements will fall within the scope of this Invention. In
the
drawings :
Figuras 1 a and 1 b arA schematic cross-section views of first and second
preferred embodiments of a kettle according to one aspect of the present
3 0 invention;
Figure 2 is a view similar to Figures 1 a and t b but showing a third
preferred embodiment;
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Figure 3 is a cross-sectional view of the lower section of a cordless kettle
according to a further preferred embodiment; and
Figure 4 is a view similar to Figure 3 showing a still further preferred
embodiment.
Figure 1 of the drawings shows schematically a first embodiment of a
cordless kettle 10 having a base section 11 and an upper section 12 defining a
water receiving vessel having a water retaining compartment 13. An upper
opening 14 p~rmits discharge or introduction of water from or to the
compartment 13. An electric resistance heating element 16 of any conventional
1 0 design is provided in a lower region of the compartment 13 and connection
of
power to the element 16 is achieved by an appropriate power connection
means 17 acting between the vessel 12 and the base section 11. The power
connection means comprises appropriate first contacts 18 (one of which is
illustrated) carried by the vessel 12 which electrically engage with second
1 5 contacts 19 (again one of which is illustrated) located in the base
section 11.
The contacts are electrically engaged when the vessel 12 is engaged an the
base 11 In the position Illustrated. Power Is supplied Pram an external source
through a normal supply cord 20 and via an ~lectrical connection 21 to the
contacts 19. A steam delivery path 22 is provld9d via a riser tube 23
internally
20 of the vessel leading from an upper end 24 adjacent but below a top wall 25
of
the vessel through the base wall 26 of the vessel 12. In an alternative
embodiment the steam delivery path may be located externally of the vessel 12.
The passage 27 defined by the riser tube 23 opens at its lower end over an
opening 28 in the tap wall 29 of the base section 11. The opening 28 is
located
2 5 directly adjacent a thermally responsive switch means 30 which may be a
bimetalllc switch or any other similar device. This switch means 30 is adapted
to break the electrical connection to at (east one of the second contacts 19
when
steam passes dawn the passage 27 upon water boiling In the vessel 12.
Appropriate reset means (not shown) would be provided in this and other
embodiments
3 0 described hereinafter to reset the switch means 30 to reactivate the
kettle when and if
desired. The reset means may be of any conventional type and further may be
automatically operated or may be of the type requiring manual intervention.
Figure 1b
represents a still further embodiment where the switch means 30 is
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formed by at least one of the active second contacts 19 being itself formed as
an
electrically conductive Thermally responsive member capable of moving to the
position 31 shown in dotted outline upon sensing a predetermined temperature
level. This predetermined t~nnperature level is achieved by providing a
further
passage 32 in the base section 11 leading from the opening 28 to a discharge
end 33 adjacent t0 the contact 19. it wilt of course be appreciated that the
positioning of the steam flow passagos and other illustrated integers may be
varied to suit manufacturing techniques as may be desir~d, Figure 2
illustrates
a still further embodiment somewhat similar to Figure 1 b except in this case
the
1 0 steam flow passage 27 opens through a side wall of the vessel 12 Into a
passage 34 leading to a discharge opening 35 which again is located adjacent
a thermally responsive member forming a second contact 19.
Figures 3 and 4 illustrate still further preferred embodiments wherein the
vessel 12 can be connected to the base section 11 in any angular configuration
1 5 about a central axis 36. In this case the power connection means 17
between
the base suction 11 and the vessel 12 permits relativ~ rotation between the
'two
parts while still maintaining the power connection. The base section 11
includes a central annular wall 37 projecting upwardly from the b~~ station
top
wall 29 adapted to project into a space dofinad by an annular wall 38
projecting
20 inwardly from the botkom wall 26 of the vessel 12. A wall 39 spans the top
of the
annular wall 38 and a boss 40 projects downwardly from this wall. The boss 40
as-an internal annular space 41 which divides the boss 40 into a central pin
42
and an outer annular wall 43, A first annular contact ring 44 is fixed to an
Inner
surface of the outer annular wall 43 and a second annular contact ring 45 is
25 fixed to an outer surface of the central pin 42. Within the central pin 42,
a third
contact 46 is formed adapted to receive an upwardly projecting contact pin 47
located within the base section 11. An annular wall 48 Is also carried within
the
base section 11 located around the oonte~ct p1n .4~'. Contact efiripo 49, 60
are
also provided, one outwardly of tho wall 48 and one inwardly of the wall 48 so
30 as~~o rvspeGtively electrically engage the contact rings 44p 46 when
connected
as';shown in Figure 3. The arrangement is such as to allow the vessel 12 and
the, base sectian 11 to be connected in any angular position and be rotated
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relative to one another. A steam path 22 is formed by a tube 23 forming a
passage 27 leading from an upper region in the vessel 12 through its base wall
26 into a steam trap 51 located between a pair of annular downwardly
depending walls 52, The walls 52 are adapted to fit within an annular upwardly
open space 53 formed within the base section 11. one opening 54 leads
through a base wall 55 of the space 53 and is adapted to diroct steam into a
thermally responsive switch means 30 (of any desired type) which will break
the
pow~r connection from lead 20 to tho connection means 17, Thus, pow~r is
disconnected from the heating olement 16 when water boils within the vessel
1 0 12. Any suitable reset means (not shown) would be provided to reset tho
switch
means 30 to recommence kettle operation when desired. ~ Figure 4 illustrates
schematically a modification of the embodiment of Fgure 3. In this case at
least
one of the contact strips 49, 50 is formed as a thermally responsive member
(bimetallic or the Ilke) to form the switch means 30 and the steam path 22
leads
1 5 directly into the space 41 to be directed onto the contact strips 49, 50
when
water boils within the kettle. The arrangement disclosed uses inner and outer
annular manifolds 56, 57 In the wall 37 connected by a number of flow
openings. Th~ inner manifold 56 communicates with one or mere openings 58
in the wall 40. If necessary, an insulation strip 59 may b~ carried an each of
the
20 contact strips 49, 54. Again a suitable reset mechanism (not illustrated)
would
be used to reactive the kettle when desired.
