CA2238813A1 - Improvements relating to electrically powered liquid heating appliances and controls therefor - Google Patents
Improvements relating to electrically powered liquid heating appliances and controls therefor Download PDFInfo
- Publication number
- CA2238813A1 CA2238813A1 CA 2238813 CA2238813A CA2238813A1 CA 2238813 A1 CA2238813 A1 CA 2238813A1 CA 2238813 CA2238813 CA 2238813 CA 2238813 A CA2238813 A CA 2238813A CA 2238813 A1 CA2238813 A1 CA 2238813A1
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- CA
- Canada
- Prior art keywords
- appliance
- combination
- power connector
- protection control
- connector
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J27/00—Cooking-vessels
- A47J27/21—Water-boiling vessels, e.g. kettles
- A47J27/21008—Water-boiling vessels, e.g. kettles electrically heated
- A47J27/2105—Water-boiling vessels, e.g. kettles electrically heated of the cordless type, i.e. whereby the water vessel can be plugged into an electrically-powered base element
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J27/00—Cooking-vessels
- A47J27/21—Water-boiling vessels, e.g. kettles
- A47J27/21008—Water-boiling vessels, e.g. kettles electrically heated
- A47J27/21058—Control devices to avoid overheating, i.e. "dry" boiling, or to detect boiling of the water
- A47J27/21066—Details concerning the mounting thereof in or on the water boiling vessel
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- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Cookers (AREA)
Abstract
A cordless electrical appliance (10) such as an electrical kettle has an element protection control (1) and an appliance power connector (4), the element protection control (1) and the appliance connector (4) being separate items which are coupled to respective ends of an elongate mounting bracket (18). The mounting bracket is affixed to the underside (16) of a planar heating element (12) by stud formations (17). By virtue of this arrangement the number of formations (17) provided on the planar heating element (12) can be minimized.
Description
- CA 02238813 1998-0~-27 I~PRoVE~E~rT~ REL~TING TO E~ECT~IC~LLY P~WE~ED
LIQ~ID ~EA~ING APP~ NCES P~nD CO ~ ROLS T~E~EFOR
Field of the Invention:
This invention concerns improvements relating to electrically powered liquid heating appliances and controls there~or. Th-e present invention may be applied to liquid heating appliances such as electric kettles, hot water jugs, urns, pans, laboratory equipment etc., and in the ~ollowing the invention will be described with re~erence to electric kettles and hot water jugs though it is to be understood that the invention is not limited to such appliances.
Backqround o~ the Invention:
In the ~ield o~ electric kettle design, there has been a recent move awa~ ~rom the use o~ conventional metal sheathed heating elements to using planar heating elements. Planar heating elements have previously been incorporated into metal bodied appliances without undue di~iculty, ~or example by forming the element as a bottom wall o~ the metal liquid heating vessel. With the widespread availability o~ lighter and cheaper plastics materials, plastics moulded liquid heating appliances -CA 02238813 1998-0~-27 have become popular. However, the incorporation of a planar heating element in such appliances has ~een more complicated.
In European Patent EP 0 285 839 there is described a kettle havlnq a moulded plastics body and incorporating a planar heating element as a bottom wall of the liquid heating vessel. The planar heating element is supported on a projecting ledge of the plastics body and has a large downwardly projecting pillar at the centre of its lower face. The element is clamped against a seal by securing a moulded bottom cover, which has a clamping flange around its periphery for engaging the projecting ledge, to the downwardly projecting pillar with a nut. An element protection control, for switching o~f the appliance in the event of an overtemperature condition arising at the heating element, is provided on the underside o~
the planar heating element and is wired to a power connector at the side of the appliance. This design is not suitable for cordless appliances and the central pillar prevents the desirable positioning o~
the power connector at the centre of the kettle base.
It is also known from International Patent Application W094/18807, to provide a planar heating element mounted on an integral element protection control and power connector provided in an opening of CA 02238813 1998-0~-27 a base wall of an appliance. The element is held in place by fasteners which pass through holes in the integral protection control and power connector and which are secured in the heating element. A sealing ring is provided between the raised planar element and the base wall to provide a watertight seal. A problem with such an arrangement is that it has among other things an overhanging eiement which is dif~icult to clean and an increased ~; ni mum water volume to be heated. In addition, such an arrangement lacks flexibility, the integration of the element protection control with the power connector limiting the ability of the appliance designer to design appliances with freedom and furthermore, imposing severe tolerance constraints upon the manufacturers of such appliances.
Recently, there has been produced a cordless electric kettle incorporating a flat heating element.
Cordless appliances have power supplied to the appliance proper via a base unit, the appliance proper and the base unit having complementary electrical connector parts adapted to come together to provide appropriate electrical connections through the base unit to the heating element in the appliance proper when the latter is seated on the base. An element protection control is mounted directly onto the underside of the element by fixing formations on the ... .~, . . .
CA 02238813 1998-0~-27 element. In addition, an appliance power connector is indirectly mounted onto the element via a metal mounting bracket. A moulded plastics bottom cover of the kettle is held in place by screws w~ich pass through mounting holes of the connector, through holes in the bracket and which are screwed into a specially formed plastics moulding that is provided between the connector and the element. The construction o~ this kettle requires two separate mounting operations to secure the control and connector to the heating element. In addition, two additional flexible cables are required to make the electrical connections.
These cables are quite expensive, being insulated with high temperature resistant insulation.
Ob~ects and SummarY of the Invention:
An object of the present invention is to overcome or substantially reduce at least some of the aforementioned problems.
According to the present invention, in one of its aspects, there is provided a combination of an element protection control and an appliance power connector which are each coupled to a mounting bracket for mounting to a heating element of the appliance.
The provision of a mounting bracket is advantageous over the known arrangements because it CA 02238813 1998-0~-27 .-enables both the element protection control and the appliance power connector to be affixed to the heating element at a single location. Accordingly, separate mounting studs or the like need not be provi~ed on the heating element ~or each of the control and the connector as in the conventional arrangements.
Furthermore, the provision o~ the mounting bracket enables the assembly of the kettle to be simplified with the mounting of the control and connector being carried out in a single operation.
The mounting bracket preferably includes means for accommodating small di~erences in the mounting position of the appliance power connector relative to the heating element. More specifically, the lS accommodating means may for example comprise an elongate through-hole in the mounting bracket for co-operating with a threaded ~astener over a range of different positions. This feature provides ~or greater positional tolerance between mounting formations on the heating element to which the mounting bracket is fixed and mounting formations on a bottom cover of the appliance which may be affixed to the connector.
The present invention also extends to an electrically powered heating appliance comprising a liquid heating vessel and a bottom cover and including .
:.
CA 02238813 1998-0~-27 ~-~
an element protection control, an appliance power connector and a mounting bracket according to the teachings hereof. The invention is particularly, though not exclusively, applicable to liquid heating appliances wherein the electrical heating element o~
the appliance is of the planar type, for example as is described in British Patent Application GB-A-2 283 155.
The above and further features of the present invention are set forth with particularity in the appended claims and together with the advantages thereof will become clear from consideration of the following detailed description of an exemplary embodiment of the invention which is illustrated in the accompanying drawings.
DescriPtion of the Drawin~s:
Figure 1 is a perspective view of an element protection control generally in accordance with the teachings of GB-A-2 194 099 and GB-A-2 248 724, specifically in accordance with the teachings o~
British Patent Application GB 9S22594.2 a copy whereo~
is appended as an integral part hereof and as used in the hereinafter described exemplary embodiment of the present invention;
Figure 2 is a.. perspective view of an appliance -CA 02238813 1998-0~-27 power connector in accordance with the teachings of W094/06185, specifically in accordance with the teachings of the abovementioned and appended British Patent Application No. 9522594.2 and as used in the hereinafter described exemplary embodiment o~ the present invention; and Fisure 3 is a part sectional, part cut-away side elevation view showing the element protection control of Figure 1 and the appliance power connector of Figure 2 connected together and to a mounting brac~et serving additionally for mounting a heating element in a liquid heating appliance.
Detailed DescriPtion of the Embodiment:
Referring first to Figure 1 of the accompanying drawings, there is illustrated therein an element protection control 1 which is a modified form of the control that is desc~ibed in GB-A-2 194 099 with reference to Figures 3A, 3B and 3C thereof, or a modified form of the control that is described in GB-A-2 248 724, or a modified form of the controls that are described in GB-A-2 283 155 and GB-A-2 283 156.
More specifically, the element protection control 1 is as described in the appended copy of British Patent Application No. 9522594.2 which forms an integral part hereof. Reference should be had to the aforementioned , .,. ~ ",j, ,~, CA 02238813 1998-0~-27 specifications and to the appended copy of British Patent Application No. 9522594.2 for a full understanding of all aspects and advantages of the element protection control 1 which will be described only briefly in the following. The disclosures of GB-A-2 194 099, GB-A-2 248 724, GB-A-2 283 155 and GB-A-2 283 156 are incorporated herein by reference and the disclosure of British Patent Application No. 9522594.2 is incorporated into this description by provision of the appended copy.
The element protection control 1 provides for the supply of electric current through the control to the heating element of an electrically powered water heating vessel or the like to which the control is affixed, subject to the condition of a bimetallic blade 2 of the control. The bimetallic blade 2 is held in close thermal contact with the heating element and in response to an element overtemperature condition is arranged to open a set of switching contacts within the control thereby to interrupt the supply of electric current through the control. The bimetallic blade 2 is snap-acting in its operation and acts upon a push-rod to open the switching contacts.
A secondary level of protection is afforded by mounting the bimetallic blade 2 on a carrier 3 which is formed of a plastics material having a CA 02238813 1998-0~-27 .
predetermined melting temperature, the carrier being under spring pressure in use of the control and being arranged so that in the event, however unlikely, of the bimetallic blade 2 failing to operate so that the heating element temperature continues to rise the carrier will begin to soften and will deform under its spring pressure so enabling a set of spring contacts to open within the control. Further details of the general construction and operation of the control 1 will become clear from consideration of the above-referenced specifications.
The appliance power connector 4 shown in Figure 2 is an appliance connector inlet part of a plug-and-socket type cordless connection system substantially as described in W0 94/06185 with reference to Figures 7 to 11 thereof. More particularly, the appliance connector inlet part 4 is similar in its construction to the part 130 shown in Figure 8B of the drawings of W0 94/06185 and is adapted to be mated with a complementary plug or appliance connector part 23 (see Figure 3 of the accompanying drawings) which is substantially as shown in Figure 9 of W0 94/0618S, the appliance connector and appliance connector inlet parts being con~igured to enable relative rotation between the two parts throughout a full 360~ of rotation. The appliance CA 02238813 1998-0~-27 ~' connector inlet part 4 comprises a generally cylindrical cup-shaped member 5 formed of moulded plastics material and having a central pillar (not shown) ~ormed with a central opening. An earth or ground terminal is provided centrally of the opening, a neutral terminal is provided in the side wall o~ the opening and a live terminal is provided on the outside wall of the pillar. As shown in Figure 2 which shows the cup-shaped appliance connector inlet part 4 in inverted position, the earth, neutral and live terminals are connected to respective spade or tab terminals 6, 7 and 8.
The element protection control 1 of Figure 1 and the appliance connector inlet part 4 of Figure 2 are adapted and arranged to be directly electrically coupled to each other in the manner described in aforementioned British Patent Application No.
9522594.2. As described therein the element protection control 1 and the appliance connector inlet part 4 may be successfully mated with each other with the terminal parts 7 and 8 of the latter engaged in recesses of the ~ormer throughout a range of relative positions and relative orientations of the two parts.
This is advantageous in that it facilitates manufacture to larger tolerances. Furthermore, again as described in British Patent Application CA 02238813 1998-0~-27 No. 9522594.2, the element protection control l may be coupled on top of the appliance connector inlet part 4, thereby enabling a li~uid heating vessel to be designed with a smaller diameter than would -otherwise be possible, or the two parts may be adapted to be interconnected in side-by-side relationship thus providing a lower overall height than the 'on top' configuration.
Referring to Figure 3 there is shown a cordless li~uid heating appliance 10, such as a cordless kettle, embodying the present invention. The appliance 10 has a plastics walled vessel 11 and a substantially planar electrical heating element 12 provided as a bottom wall of the vessel ll. The heating element 12 is supported on an inwardly projecting ledge or seat 13 of the vessel ll and is sealed thereto to be water-tight by means of a ring seal 14.
The heating element 12 is made of stainless steel Zo to prevent corrosion occurring on the upper face 15 thereof. The lower face 16 of the heating element 12 has a layer of aluminium spun thereon to improve the distribution of heat across the element 12, and also to provide a mounting surface for the appliance controls. A resistance heating element (not shown) is clenched into the aluminium layer in a manner known CA 02238813 1998-0~-27 per se. At a central region of the lower sur~ace 16, two spaced-apart stud ~ormations 17 are provided for ~ixing a pair of elongate mounting brac~ets 18 to the heating element lZ. Only a single ~ormation 17 and mounting bracket 18 can be seen in Figure 3 because the other formation 17 and bracket 18 are provided directly behind those shown in Figure 3 and are not visible in the side view of this Figure.
The element protection control 1 is secured by rivets for example to one end of each of the mounting brackets 18 so as to enable the bimetal 2 and the plastics material carrier 3 to be located in close thermal contact with the underside of the heating element 12, the rivets passing through the holes 30 provided in the control 1. Power is supplied to the element protection control l by way of the appliance connector inlet part 4 which is directly electrically coupled to the controI 1 in the previously mentioned 'on top' configuration and, dependent upon the condition of the control, is transferred through the control and to electrical terminations o~ the heating element by means of electrical conductors. The appliance connector inlet part 4 is mounted to the other ends of the elongate mounting brackets 18, the brackets 18 being so shaped as to support and secure the inlet part 4 in operative relationship with the ~ .~.
CA 02238813 1998-0~-27 ~
.. .
element protection control 1. However, it is also possible for the mounting brackets to be so shaped as to mount the element protection control 1 and the inlet part 4 in the previously mentioned side-by-side configuration.
The connector inlet part 4 is provided on opposite sides thereof with mounting lugs 19 (see Figure Z). The elongate mounting brackets 18 include through-holes 20 at the ends thereof which are adapted to align with the mounting lugs 19 of the inlet part 4 when the latter is positioned in the base of the appliance 10. Screws 21 pass through the holes 20 and into the mounting lugs 19 to fix the inlet part 4 to the mounting brackets 18.
A bottom cover 22 of the appliance 10 is also secured to the mounting brackets 18 by the screws 21 which pass through apertures in the cover 22 which are aligned with the mounting lugs 19. The bottom cover 22 engages the inwardly pro~ecting ledge 13 of the vessel 11, and the arrangement is such that the effect of securing the bottom cover 22 to the mounting brac~ets 18 is to pull the heating element 12 down onto the ring seal 14. Accordingly, when the appliance 10 is thus assembled, the heating element 12 is effectively sealed with respect to the interior of the vessel 11.
CA 02238813 1998-0~-27 The provision of mounting lugs 19 on the inlet part 4 is par'icularly advantageous because it obviates the need for the provision of a specially ~ormed plastics moulding as is required in the aforementioned recently produced cordless electric kettle. In addition, the reduced number of components required for assembly of the appliance advantageously reduces the cost of the appliance.
The through-holes 20 in the mounting brackets 18 are oversized (elongate) so as to allow relative movement of the connector inlet part 4 and the bottom cover 22 with respect to the heating element 12. The bottom cover 22 is always accurately aligned with the connector inlet part 4 but may be positionally adjusted within the clearance in the through-holes 20 during assembly to accommodate tolerances in the heating element manufacture.
Figure 3 shows thë cordless appliance 10 set upon its base 24 with the complementary base connector part 23 of the cordless connection system engaged with the appliance connector inlet part 4. The base connector part 23 is substantially as described in W0 94/06185.
Having thus described the present invention by reference to a specific embodiment, it is to be well appreciated that modifications and variations thereto are possible without departure from the spirit and CA 02238813 1998-0~-27 ~-.
scope of the present invention as set forth in the appended claims. For example, the present inventian is not limited to the herein described kind of element protection control and is not limited to tne herein described kind o~ cordless connection system. In fact, the present invention could be readily applied to a corded rather than a cordless appliance, i.e. an appliance in which power is supplied to the appliance connector inlet via a flexible power cord. In addition, whereas the above described embodiment uses two mounting brackets, these could readily be replaced by a single mounting bracket per~orming the same function. The invention furthermore is not limited to use with planar electric heating elements of the described kind, but could also be used with other kinds of planar electric heating elements such as those of the kind which comprise a substrate having a resistance heating trac~ or layer formed thereupon.
One such element which has been proposed comprises a stainless steel substrate having an electrically insulating layer ~ormed on one side thereof, a resistance heating track or layer formed on the electrically insulating layer and a further electrically insulating layer formed over the resistance heating track or layer. As disclosed in GB-A-2 283 156, openings can be provided in the CA 022388l3 l998-05-27 ;~
last-mentioned electrically insulating layer to provide power supply terminations o~ the heating element, and the element protection control can ~e ~ormed with spring terminals arranged to contact said power sl~pply terminations when the control is operatively juxtaposed with the heating element.
There follows a copy o~ British Patent Application No. 9522594.2 as an integral and essential part of the ~oregoing description.
LIQ~ID ~EA~ING APP~ NCES P~nD CO ~ ROLS T~E~EFOR
Field of the Invention:
This invention concerns improvements relating to electrically powered liquid heating appliances and controls there~or. Th-e present invention may be applied to liquid heating appliances such as electric kettles, hot water jugs, urns, pans, laboratory equipment etc., and in the ~ollowing the invention will be described with re~erence to electric kettles and hot water jugs though it is to be understood that the invention is not limited to such appliances.
Backqround o~ the Invention:
In the ~ield o~ electric kettle design, there has been a recent move awa~ ~rom the use o~ conventional metal sheathed heating elements to using planar heating elements. Planar heating elements have previously been incorporated into metal bodied appliances without undue di~iculty, ~or example by forming the element as a bottom wall o~ the metal liquid heating vessel. With the widespread availability o~ lighter and cheaper plastics materials, plastics moulded liquid heating appliances -CA 02238813 1998-0~-27 have become popular. However, the incorporation of a planar heating element in such appliances has ~een more complicated.
In European Patent EP 0 285 839 there is described a kettle havlnq a moulded plastics body and incorporating a planar heating element as a bottom wall of the liquid heating vessel. The planar heating element is supported on a projecting ledge of the plastics body and has a large downwardly projecting pillar at the centre of its lower face. The element is clamped against a seal by securing a moulded bottom cover, which has a clamping flange around its periphery for engaging the projecting ledge, to the downwardly projecting pillar with a nut. An element protection control, for switching o~f the appliance in the event of an overtemperature condition arising at the heating element, is provided on the underside o~
the planar heating element and is wired to a power connector at the side of the appliance. This design is not suitable for cordless appliances and the central pillar prevents the desirable positioning o~
the power connector at the centre of the kettle base.
It is also known from International Patent Application W094/18807, to provide a planar heating element mounted on an integral element protection control and power connector provided in an opening of CA 02238813 1998-0~-27 a base wall of an appliance. The element is held in place by fasteners which pass through holes in the integral protection control and power connector and which are secured in the heating element. A sealing ring is provided between the raised planar element and the base wall to provide a watertight seal. A problem with such an arrangement is that it has among other things an overhanging eiement which is dif~icult to clean and an increased ~; ni mum water volume to be heated. In addition, such an arrangement lacks flexibility, the integration of the element protection control with the power connector limiting the ability of the appliance designer to design appliances with freedom and furthermore, imposing severe tolerance constraints upon the manufacturers of such appliances.
Recently, there has been produced a cordless electric kettle incorporating a flat heating element.
Cordless appliances have power supplied to the appliance proper via a base unit, the appliance proper and the base unit having complementary electrical connector parts adapted to come together to provide appropriate electrical connections through the base unit to the heating element in the appliance proper when the latter is seated on the base. An element protection control is mounted directly onto the underside of the element by fixing formations on the ... .~, . . .
CA 02238813 1998-0~-27 element. In addition, an appliance power connector is indirectly mounted onto the element via a metal mounting bracket. A moulded plastics bottom cover of the kettle is held in place by screws w~ich pass through mounting holes of the connector, through holes in the bracket and which are screwed into a specially formed plastics moulding that is provided between the connector and the element. The construction o~ this kettle requires two separate mounting operations to secure the control and connector to the heating element. In addition, two additional flexible cables are required to make the electrical connections.
These cables are quite expensive, being insulated with high temperature resistant insulation.
Ob~ects and SummarY of the Invention:
An object of the present invention is to overcome or substantially reduce at least some of the aforementioned problems.
According to the present invention, in one of its aspects, there is provided a combination of an element protection control and an appliance power connector which are each coupled to a mounting bracket for mounting to a heating element of the appliance.
The provision of a mounting bracket is advantageous over the known arrangements because it CA 02238813 1998-0~-27 .-enables both the element protection control and the appliance power connector to be affixed to the heating element at a single location. Accordingly, separate mounting studs or the like need not be provi~ed on the heating element ~or each of the control and the connector as in the conventional arrangements.
Furthermore, the provision o~ the mounting bracket enables the assembly of the kettle to be simplified with the mounting of the control and connector being carried out in a single operation.
The mounting bracket preferably includes means for accommodating small di~erences in the mounting position of the appliance power connector relative to the heating element. More specifically, the lS accommodating means may for example comprise an elongate through-hole in the mounting bracket for co-operating with a threaded ~astener over a range of different positions. This feature provides ~or greater positional tolerance between mounting formations on the heating element to which the mounting bracket is fixed and mounting formations on a bottom cover of the appliance which may be affixed to the connector.
The present invention also extends to an electrically powered heating appliance comprising a liquid heating vessel and a bottom cover and including .
:.
CA 02238813 1998-0~-27 ~-~
an element protection control, an appliance power connector and a mounting bracket according to the teachings hereof. The invention is particularly, though not exclusively, applicable to liquid heating appliances wherein the electrical heating element o~
the appliance is of the planar type, for example as is described in British Patent Application GB-A-2 283 155.
The above and further features of the present invention are set forth with particularity in the appended claims and together with the advantages thereof will become clear from consideration of the following detailed description of an exemplary embodiment of the invention which is illustrated in the accompanying drawings.
DescriPtion of the Drawin~s:
Figure 1 is a perspective view of an element protection control generally in accordance with the teachings of GB-A-2 194 099 and GB-A-2 248 724, specifically in accordance with the teachings o~
British Patent Application GB 9S22594.2 a copy whereo~
is appended as an integral part hereof and as used in the hereinafter described exemplary embodiment of the present invention;
Figure 2 is a.. perspective view of an appliance -CA 02238813 1998-0~-27 power connector in accordance with the teachings of W094/06185, specifically in accordance with the teachings of the abovementioned and appended British Patent Application No. 9522594.2 and as used in the hereinafter described exemplary embodiment o~ the present invention; and Fisure 3 is a part sectional, part cut-away side elevation view showing the element protection control of Figure 1 and the appliance power connector of Figure 2 connected together and to a mounting brac~et serving additionally for mounting a heating element in a liquid heating appliance.
Detailed DescriPtion of the Embodiment:
Referring first to Figure 1 of the accompanying drawings, there is illustrated therein an element protection control 1 which is a modified form of the control that is desc~ibed in GB-A-2 194 099 with reference to Figures 3A, 3B and 3C thereof, or a modified form of the control that is described in GB-A-2 248 724, or a modified form of the controls that are described in GB-A-2 283 155 and GB-A-2 283 156.
More specifically, the element protection control 1 is as described in the appended copy of British Patent Application No. 9522594.2 which forms an integral part hereof. Reference should be had to the aforementioned , .,. ~ ",j, ,~, CA 02238813 1998-0~-27 specifications and to the appended copy of British Patent Application No. 9522594.2 for a full understanding of all aspects and advantages of the element protection control 1 which will be described only briefly in the following. The disclosures of GB-A-2 194 099, GB-A-2 248 724, GB-A-2 283 155 and GB-A-2 283 156 are incorporated herein by reference and the disclosure of British Patent Application No. 9522594.2 is incorporated into this description by provision of the appended copy.
The element protection control 1 provides for the supply of electric current through the control to the heating element of an electrically powered water heating vessel or the like to which the control is affixed, subject to the condition of a bimetallic blade 2 of the control. The bimetallic blade 2 is held in close thermal contact with the heating element and in response to an element overtemperature condition is arranged to open a set of switching contacts within the control thereby to interrupt the supply of electric current through the control. The bimetallic blade 2 is snap-acting in its operation and acts upon a push-rod to open the switching contacts.
A secondary level of protection is afforded by mounting the bimetallic blade 2 on a carrier 3 which is formed of a plastics material having a CA 02238813 1998-0~-27 .
predetermined melting temperature, the carrier being under spring pressure in use of the control and being arranged so that in the event, however unlikely, of the bimetallic blade 2 failing to operate so that the heating element temperature continues to rise the carrier will begin to soften and will deform under its spring pressure so enabling a set of spring contacts to open within the control. Further details of the general construction and operation of the control 1 will become clear from consideration of the above-referenced specifications.
The appliance power connector 4 shown in Figure 2 is an appliance connector inlet part of a plug-and-socket type cordless connection system substantially as described in W0 94/06185 with reference to Figures 7 to 11 thereof. More particularly, the appliance connector inlet part 4 is similar in its construction to the part 130 shown in Figure 8B of the drawings of W0 94/06185 and is adapted to be mated with a complementary plug or appliance connector part 23 (see Figure 3 of the accompanying drawings) which is substantially as shown in Figure 9 of W0 94/0618S, the appliance connector and appliance connector inlet parts being con~igured to enable relative rotation between the two parts throughout a full 360~ of rotation. The appliance CA 02238813 1998-0~-27 ~' connector inlet part 4 comprises a generally cylindrical cup-shaped member 5 formed of moulded plastics material and having a central pillar (not shown) ~ormed with a central opening. An earth or ground terminal is provided centrally of the opening, a neutral terminal is provided in the side wall o~ the opening and a live terminal is provided on the outside wall of the pillar. As shown in Figure 2 which shows the cup-shaped appliance connector inlet part 4 in inverted position, the earth, neutral and live terminals are connected to respective spade or tab terminals 6, 7 and 8.
The element protection control 1 of Figure 1 and the appliance connector inlet part 4 of Figure 2 are adapted and arranged to be directly electrically coupled to each other in the manner described in aforementioned British Patent Application No.
9522594.2. As described therein the element protection control 1 and the appliance connector inlet part 4 may be successfully mated with each other with the terminal parts 7 and 8 of the latter engaged in recesses of the ~ormer throughout a range of relative positions and relative orientations of the two parts.
This is advantageous in that it facilitates manufacture to larger tolerances. Furthermore, again as described in British Patent Application CA 02238813 1998-0~-27 No. 9522594.2, the element protection control l may be coupled on top of the appliance connector inlet part 4, thereby enabling a li~uid heating vessel to be designed with a smaller diameter than would -otherwise be possible, or the two parts may be adapted to be interconnected in side-by-side relationship thus providing a lower overall height than the 'on top' configuration.
Referring to Figure 3 there is shown a cordless li~uid heating appliance 10, such as a cordless kettle, embodying the present invention. The appliance 10 has a plastics walled vessel 11 and a substantially planar electrical heating element 12 provided as a bottom wall of the vessel ll. The heating element 12 is supported on an inwardly projecting ledge or seat 13 of the vessel ll and is sealed thereto to be water-tight by means of a ring seal 14.
The heating element 12 is made of stainless steel Zo to prevent corrosion occurring on the upper face 15 thereof. The lower face 16 of the heating element 12 has a layer of aluminium spun thereon to improve the distribution of heat across the element 12, and also to provide a mounting surface for the appliance controls. A resistance heating element (not shown) is clenched into the aluminium layer in a manner known CA 02238813 1998-0~-27 per se. At a central region of the lower sur~ace 16, two spaced-apart stud ~ormations 17 are provided for ~ixing a pair of elongate mounting brac~ets 18 to the heating element lZ. Only a single ~ormation 17 and mounting bracket 18 can be seen in Figure 3 because the other formation 17 and bracket 18 are provided directly behind those shown in Figure 3 and are not visible in the side view of this Figure.
The element protection control 1 is secured by rivets for example to one end of each of the mounting brackets 18 so as to enable the bimetal 2 and the plastics material carrier 3 to be located in close thermal contact with the underside of the heating element 12, the rivets passing through the holes 30 provided in the control 1. Power is supplied to the element protection control l by way of the appliance connector inlet part 4 which is directly electrically coupled to the controI 1 in the previously mentioned 'on top' configuration and, dependent upon the condition of the control, is transferred through the control and to electrical terminations o~ the heating element by means of electrical conductors. The appliance connector inlet part 4 is mounted to the other ends of the elongate mounting brackets 18, the brackets 18 being so shaped as to support and secure the inlet part 4 in operative relationship with the ~ .~.
CA 02238813 1998-0~-27 ~
.. .
element protection control 1. However, it is also possible for the mounting brackets to be so shaped as to mount the element protection control 1 and the inlet part 4 in the previously mentioned side-by-side configuration.
The connector inlet part 4 is provided on opposite sides thereof with mounting lugs 19 (see Figure Z). The elongate mounting brackets 18 include through-holes 20 at the ends thereof which are adapted to align with the mounting lugs 19 of the inlet part 4 when the latter is positioned in the base of the appliance 10. Screws 21 pass through the holes 20 and into the mounting lugs 19 to fix the inlet part 4 to the mounting brackets 18.
A bottom cover 22 of the appliance 10 is also secured to the mounting brackets 18 by the screws 21 which pass through apertures in the cover 22 which are aligned with the mounting lugs 19. The bottom cover 22 engages the inwardly pro~ecting ledge 13 of the vessel 11, and the arrangement is such that the effect of securing the bottom cover 22 to the mounting brac~ets 18 is to pull the heating element 12 down onto the ring seal 14. Accordingly, when the appliance 10 is thus assembled, the heating element 12 is effectively sealed with respect to the interior of the vessel 11.
CA 02238813 1998-0~-27 The provision of mounting lugs 19 on the inlet part 4 is par'icularly advantageous because it obviates the need for the provision of a specially ~ormed plastics moulding as is required in the aforementioned recently produced cordless electric kettle. In addition, the reduced number of components required for assembly of the appliance advantageously reduces the cost of the appliance.
The through-holes 20 in the mounting brackets 18 are oversized (elongate) so as to allow relative movement of the connector inlet part 4 and the bottom cover 22 with respect to the heating element 12. The bottom cover 22 is always accurately aligned with the connector inlet part 4 but may be positionally adjusted within the clearance in the through-holes 20 during assembly to accommodate tolerances in the heating element manufacture.
Figure 3 shows thë cordless appliance 10 set upon its base 24 with the complementary base connector part 23 of the cordless connection system engaged with the appliance connector inlet part 4. The base connector part 23 is substantially as described in W0 94/06185.
Having thus described the present invention by reference to a specific embodiment, it is to be well appreciated that modifications and variations thereto are possible without departure from the spirit and CA 02238813 1998-0~-27 ~-.
scope of the present invention as set forth in the appended claims. For example, the present inventian is not limited to the herein described kind of element protection control and is not limited to tne herein described kind o~ cordless connection system. In fact, the present invention could be readily applied to a corded rather than a cordless appliance, i.e. an appliance in which power is supplied to the appliance connector inlet via a flexible power cord. In addition, whereas the above described embodiment uses two mounting brackets, these could readily be replaced by a single mounting bracket per~orming the same function. The invention furthermore is not limited to use with planar electric heating elements of the described kind, but could also be used with other kinds of planar electric heating elements such as those of the kind which comprise a substrate having a resistance heating trac~ or layer formed thereupon.
One such element which has been proposed comprises a stainless steel substrate having an electrically insulating layer ~ormed on one side thereof, a resistance heating track or layer formed on the electrically insulating layer and a further electrically insulating layer formed over the resistance heating track or layer. As disclosed in GB-A-2 283 156, openings can be provided in the CA 022388l3 l998-05-27 ;~
last-mentioned electrically insulating layer to provide power supply terminations o~ the heating element, and the element protection control can ~e ~ormed with spring terminals arranged to contact said power sl~pply terminations when the control is operatively juxtaposed with the heating element.
There follows a copy o~ British Patent Application No. 9522594.2 as an integral and essential part of the ~oregoing description.
Claims (15)
1. A combination of an element protection control, an appliance power connector and a mounting bracket for an electrically powered heating appliance, said element protection control and said appliance power connector each being coupled to said mounting bracket for mounting to a heating element of said appliance.
2. A combination as claimed in claim 1, wherein said mounting bracket includes means for permitting adjustment of the relative mounting position between the appliance power connector and the heating element.
3. A combination as claimed in claim 2, wherein said adjustment means comprises an elongate through-hole for co-operating with a fastener extending through said hole.
4. A combination as claimed in any preceding claim wherein the mounting bracket comprises an elongate member which is arranged at one end thereof to be coupled to the element protection control and at the other end thereof to be coupled to the appliance power connector.
5. A combination as claimed in any preceding claim, wherein the mounting bracket is arranged to mount said element protection control on top of said appliance power connector or in side-by-side relationship with said appliance power connector.
6. A combination as claimed in any preceding claim, wherein the appliance power connector comprises at least one mounting lug for receiving a fastener.
7. A combination as claimed in any preceding claim, wherein the element protection control and the appliance power connector comprise electrical connector parts adapted to be coupled together so as to enable effective interconnection therebetween within a range of relative positions thereof.
8. A combination as claimed in any preceding claim, wherein said element protection control comprises a bimetal mounted to a thermally collapsible carrier, the action of the bimetal is arranged to provide a primary control function, and the thermally-induced collapse of the carrier is arranged to provide a secondary or back-up control function.
9. A combination as claimed in any preceding claim wherein said appliance power connector comprises an inlet part of a cordless connection system adapted for engagement with a complementary connector part enabling engagement of the two connector parts substantially irrespective of the relative rotational orientation thereof in the plane transverse to the engagement direction of the parts.
10. A combination as claimed in claim 9 wherein said inlet part and said complementary connector part are generally coaxially arranged.
11. A combination substantially as described herein with reference to the accompanying drawings.
12. A combination as claimed in any preceding claim affixed to an electric heating element.
13. A combination as claimed in claim 12 wherein said electric heating element comprises a generally planar heating element having the element protection control, appliance power connector and mounting bracket affixed to one side thereof.
14. An electrically powered heating appliance comprising a liquid heating vessel and a combination as claimed in claim 13.
15. An electrically powered heating appliance as claimed in claim 14 wherein said planar heating element is sealingly secured in said liquid heating vessel by virtue of a bottom cover of said vessel being secured to said mounting bracket.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GBGB9524176.6A GB9524176D0 (en) | 1995-11-27 | 1995-11-27 | Improvements relating to electrically powered liquid heating appliances and controls therefor |
| GB9524176.6 | 1997-11-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2238813A1 true CA2238813A1 (en) | 1997-06-05 |
Family
ID=10784483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2238813 Abandoned CA2238813A1 (en) | 1995-11-27 | 1996-11-27 | Improvements relating to electrically powered liquid heating appliances and controls therefor |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0869730A1 (en) |
| CN (1) | CN1135091C (en) |
| AU (1) | AU2011497A (en) |
| CA (1) | CA2238813A1 (en) |
| GB (2) | GB9524176D0 (en) |
| HK (1) | HK1014625A1 (en) |
| WO (1) | WO1997019627A1 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2319154A (en) * | 1996-10-02 | 1998-05-13 | Pifco Ltd | Mounting heating element in liquid heating apparatus |
| GB2322274B (en) * | 1997-02-17 | 1999-01-13 | Strix Ltd | Controls for electric heaters |
| DE69817596T2 (en) | 1997-10-07 | 2004-06-24 | Otter Controls Ltd., Buxton | IMPROVEMENTS TO ELECTRICALLY HEATED COOKING VESSELS |
| GB2346540B (en) * | 1999-02-08 | 2002-10-09 | Otter Controls Ltd | Improvements relating tp electrically heated vessels |
| EP1858297B1 (en) * | 1999-10-11 | 2012-08-15 | Strix Limited | Cordless electrical appliances |
| DK199901805A (en) * | 1999-12-16 | 2001-06-17 | Pi Design Ag | Couplings for an electric consumer, especially for a coffee maker and means for securing the coupler |
| FR2895222B1 (en) * | 2005-12-22 | 2010-01-01 | Seb Sa | COOKING APPARATUS COMPRISING A SIMPLIFIED POWER SUPPLY AND CONTROL SUBASSEMBLY |
| CN102412489A (en) * | 2011-12-31 | 2012-04-11 | 钻宝电子有限公司 | Lower base of electric kettle socket and electric kettle socket with same |
| EP3001511B1 (en) * | 2013-05-23 | 2020-03-18 | Guangdong Xinbao Electrical Appliances Holdings Co. Ltd. | Coupler for use in liquid heater and liquid heater |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3231717A (en) * | 1963-11-15 | 1966-01-25 | Texas Instruments Inc | Electrically heated vessel and detachable temperature-regulating connector therefor |
| GB8618372D0 (en) * | 1986-07-28 | 1986-09-03 | Otter Controls Ltd | Thermal control units |
| DE3711637A1 (en) * | 1987-04-07 | 1988-10-27 | Ego Elektro Blanc & Fischer | ELECTRIC HEATING CASE |
| GB9020032D0 (en) * | 1990-09-13 | 1990-10-24 | Otter Controls Ltd | Improvements relating to thermal control units |
| WO1994006185A1 (en) * | 1992-09-02 | 1994-03-17 | Otter Controls Limited | Charging unit for cordless appliances |
| GB9302965D0 (en) * | 1993-02-15 | 1993-03-31 | Strix Ltd | Immersion heaters |
| GB2283156B (en) * | 1993-10-21 | 1997-09-17 | Otter Controls Ltd | Improvements relating to electrical heating elements and controls therefor |
| GB2283155B (en) * | 1993-10-21 | 1997-08-06 | Otter Controls Ltd | Improvements relating to electrically heated water boiling vessels |
| GB9400543D0 (en) * | 1994-01-13 | 1994-03-09 | Strix Ltd | Water heating apparatus |
| US5437003A (en) * | 1994-12-16 | 1995-07-25 | Hot Aqua Industries, Inc. | In line tankless water heater with upper heating compartment, lower wiring compartment, and microswitch compartment disposed therebetween |
-
1995
- 1995-11-27 GB GBGB9524176.6A patent/GB9524176D0/en active Pending
-
1996
- 1996-11-27 AU AU20114/97A patent/AU2011497A/en not_active Abandoned
- 1996-11-27 EP EP96942436A patent/EP0869730A1/en not_active Withdrawn
- 1996-11-27 CA CA 2238813 patent/CA2238813A1/en not_active Abandoned
- 1996-11-27 GB GB9624664A patent/GB2307602B/en not_active Expired - Fee Related
- 1996-11-27 WO PCT/GB1996/002924 patent/WO1997019627A1/en not_active Application Discontinuation
- 1996-11-27 CN CNB961996579A patent/CN1135091C/en not_active Expired - Fee Related
-
1998
- 1998-12-28 HK HK98115777A patent/HK1014625A1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| HK1014625A1 (en) | 1999-09-30 |
| GB2307602A (en) | 1997-05-28 |
| GB2307602B (en) | 2000-07-12 |
| AU2011497A (en) | 1997-06-19 |
| CN1135091C (en) | 2004-01-21 |
| EP0869730A1 (en) | 1998-10-14 |
| WO1997019627A1 (en) | 1997-06-05 |
| CN1226142A (en) | 1999-08-18 |
| GB9624664D0 (en) | 1997-01-15 |
| GB9524176D0 (en) | 1996-01-31 |
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Legal Events
| Date | Code | Title | Description |
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| FZDE | Dead |